US3839934A - Automatic tape-feed, indexing and cutting mechanism - Google Patents

Abstract

A machine for severing a strip into a plurality of strip segments, the strip having spaced reference indicia displayed thereon each at a selected distance from a corresponding position at which the strip is to be severed. The machine includes a cutter for severing the strip, a feed assembly for advancing the strip to the cutter, a probe for sensing the presence of any of the indicia at a selected position behind the cutter, and various switches for activating the feed assembly, deactivating the latter when the probe senses one of the indicia, activating the cutter when the feed assembly is deactivated, and deactivating the cutter after the strip has been severed.

Description

Unite States Patent [191 Russo Oct, 8, 1974 AUTQMATIC TAPE-FEED, INDEXING AND 3,699,832 10/1972 Smith et al 83/210 CUT'HNQ, MECHANHSM 3,760,667 9/1973 Maxey et al. 83/371 X V. N [75] Inventor Joseph Russo, ew York N Y Pumas} Exammer prank T. Yost [73] Assignee: Krakower, Samanowitz & Goldman,

N Y k, NY. ew 57 ABSTRACT [22] Med 1973 A machine for severing a strip into a plurality of strip [21] App]. No.: 355,265 'segments, the strip having spaced reference indicia displayed thereon each at a selected distance from a [52] CL 83/63 83/210 83/361 corresponding position at which the strip is to be sev- 83/365 83/371 ered The machine includes a cutter for severing the [51] Int. CL 826d 5/32B26d 5/34 strip, a feed assembly for advancing the strip to the [58] Field 's' g 'hi "83/210 1 371 365 cutter, a probe for sensing the presence of any of the indicia at a selected position behind the cutter, and

various switches for activating the feed assembly, de- [56] References Cited activating the latter when the prob-e senses one of the indicia, activating the cutter when the feed assembly is UNITED STATES PATENTS deactivated, and deactivatin the cutter after thestri 7 674 308 4/l954 K bl 83/210h b d g p n0 6 as gen evere 1 2,939,354 6/l960 King 83/2l0 X 3,559,519 2/1971 Westphal et a]. 83/210 21 Claims, 17 Drawing Figures AU;4 MODE 42 s START SWITCH MANUAL STOP FEEDSWITCH 60g y 412 4 16 416 4 20 11% a a t a 1e PROBE 'KE INVERTER J 'LE INVERTER 1l l 1 STOP c TC T c uT QZ iio P: rieg: mvzarsa FS QS TRIAC RECTIF ER CYCLE MANUAL MOTOR POWTER POWER COUNTER F FILTER CH 0*) 12v REG. 4(3240b POWER 1 408 RECTIFIER c X'FORMER FILTER \4O4 (U 35v. REG,

PAIENTEBHBT 81914 3839834 I FIG. 8

PATENTED 81974 3,839,934

SHEET 50F T FROM: REGULATOR 406 (FIG. 9)

l2 VOLTS TO CLUTCH STOP SCR 424 (FIG. l5)

T02 START CUT SCR -434 (FIG. l6)

FROM; REGULATOR 406 (FIG' 9) I2 VOLTS TO: INVERTER -4l6 (FIG. 13)

H TO

0-2 (FIGIO) TO: CLUTCH FEED Son 422 (FIG. l5)

FIG.

PATENIEU 81974 3.839.934

SHEET80F 7 FROM REGULATOR 406 (FIG. 9 l2 VOLTS T01 INVERTER 420 (FIG. l4)

FROMI INVERTER 4I6 (FlG. l3)

FIG. /2

FROM. REGULATOR 406 (FIG. 9) l2 VOLTS FROM: JUNCTION OF R-l3 a R-l4 (FIG. n)

R-4Z FROM:REGULATOR 1 40s (FIG.9) 'Wv l2 VOLTS I TO- 0-2 (FIG.IO)

FROM JUNCTION OF R-IS 8| R-l9 (FIG. 12)

To: CLUTCH STOP SCR 424 (FIG. 15)

PAIENTED 3 839.934

SHEET 7 OF 7 R-42 R-25 SWAN) FROM- REGULATOR (A40) 7 1 r 408 (FIG. 9)

-vvv\-|4 J. 35 VOLTS u C-H- W L l;

R-2b C (0 vv To: START CUT R-29 (FIG. l7) 1! SCR 434 SCR-f (FIG. I6) 424 FRoM:

FROMI 7 o:D 44 0-3 (FIG. H) 7 scR'azz FROM;

(FIG. I?) I [1-22 (FIG. I4)

I I FROMI REGULATOR 408 (FIG. 9)Icgm 35 VOLTS C-l3 SCR-A34 I FROM: 0-2 (FlG.l0) FROM: sw-s FROM- s.w-|0 (FIG. H) (FIG. l5)

T FIG. /6

FROM 1 CLUTCH FEED scR-422 (FIG. (5)

FROM START CUT SCR 454 H- T.

(FIG. (6)

FROM- REGULATOR 408 (FIG. 9) 35 VOLTS FROM JUNCTION OF L-l 8 C*IO (FIG. l5)

BACKGROUND OF THE INVENTION The present invention relates generally to a machine for severing a strip into a plurality of strip segments of selected elongate extent, and more particularly to an automatic tape-feed, indexing and cutting machine for severing microfiche, other intelligence displaying plastic-like or paper strips, and strips in general which have displayed thereon spaced cut-reference indicia each at a selected distance from a corresponding position at which the strip is to be severed.

Machines of the above type are in general well known and include a cutter for severing the strip, a feed assembly for advancing the strip to the cutter, a probe for sensing the presence of any of the indicia on the strip at a selected position behind the cutter, and various switches for both activating and deactivating the feed assembly and cutter at selected intervals.

Conventional machines of the above type have a number of disadvantages associated with them and generally cannot timely sever the strip precisely. This often results in the necessity to discard imprecisely severed strip segments as waste. In this respect, in order for the machine to precisely sever the strip, it is preferable that the probe be capable of discriminating reference indicia whose purpose is to signal cutting operations from non-reference intelligence characters displayed on the strip between the indicia. This discriminating capacity is generally absent from such conventional machines.

It is also preferable that the probe and feed assembly be operatively associated with one another in such a manner that when the probe senses one of the indicia there is an immediate deactivation of the feed assembly so that a cut position on the strip is precisely at the cutter and not beyond the latter.

However, because of the inertia of the moving mechanical parts of the machine, and the absence of a rapid acting coupling system between the electronic circuitry of the probe and the mechanically moving parts, such conventional types of cutting machines have proven to be less than precise and are, therefore, unreliable.

Moreover, because of the nature of the mechanical parts themselves, for example, the gears which are interposed between the drive motor and the stripcontacting feed elements, i.e., drive rollers and the like, there is a certain degree of backlash associated with such gears which compounds the degree of error associated with such cutting machines.

Still another disadvantage associated with such machines is the fact that whenever the switch associated with the power supply is for some reason opened during the feeding cycle of the machine, the feed assembly reacts to terminate advancement of the strip to the cutter. Upon reactivation of the machine subsequently, the cutter will act to sever the strip at the position in which it remained at the time of the previous power shut down. This may result in the severing of the strip improperly between the positions at which the strip should have severed. As a result that portion of the strip must be discarded as waste.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention is to provide an improved and novel automatic tapefeed, indexing and cutting mechanism which can discriminate cut-reference indicia from non-reference intelligence displayed on a tape or strip between the indiera.

It is another object of the present invention to provide such a machine in which there is arranged a mechanical coupling system interposed between the electronic circuitry of the probe and the strip-feeding elements which can effect a precise and immediate termi- 1 nation of the advancement of the strip when a cutreference mark on the strip is sensed by the circuitry.

It is still another object of the present invention to provide such a machine in which the drive gears for the feed assembly are of greatly improved anti-backlash nature.

It is a further object of the present invention to provide such a machine in which the feed assembly after opening of the power switch will continue for a short period to advance the strip toward the cutter until the very next indexing mark on the strip is sensed by the machine probe.

The above objects, as well as other objects which will subsequently become clear, may be achieved by pro viding' a machine which includes a cutter for severing the strip, a feed assembly for advancing the strip to the cutter, an improved probe for sensing the presence of any cut-reference indicia displayed on the Strip at a selected position behind the cutter, and a probe control system for selectively rendering the probe alternately operative and inoperative at selected intervals during the operation of the feed assembly so that nonreference intelligence displayed on the strip other than and between the indicia will fail to be sensed by the probe during the inoperative intervals thereof. A number of SCR switches are associated with the feed assembly and cutter to precisely activate and inactivate the cutter and feed assembly at selected intervals. An improved anti-backlash gear assembly is provided for driving the feed assembly to substantially obviate play or backlash between the driven and driver ars BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, characteristics and advantages of the present invention will be more clearly understood from the following detailed description thereof when read in conjunction with the accompanying drawings, in which:

FIG. I is a schematic view. in perspective of a roll of microfiche partially unwound;

FIG. 2 is a perspective view illustrating the machine pursuant to the present invention;

FIG. 3 is a schematic inverted plan view of the machine;

FIG. 4 is an elevational schematic view, partially in section, illustrating the feed and cutter actuating mechanism of the machine;

FIG. 5 is a schematic enlarged, plan view illustrating the association of the machine clntch and antibacklash gear assembly;

FIG. 6 is an enlarged schematic plan view of the clutch shown generally in FIG. 5;

FIG. 7 is an inverted, elevational, further enlarged, schematic view illustrating the anti-backlash gear assembly;

FIG. 8 is an enlarged vertical cross-sectional view of the probe of the present invention;

FIG. 9 is a diagrammatic block diagram of the electri cal control system of the present invention;

FIG. 10 illustrates the electrical circuitry of the probe and probe amplifier of the present invention;

FIG. 11 illustrates the electrical circuitry of a first time delay means of the present invention;

FIG. I2 illustrates electrical circuitry of a second time delay means pursuant to the present invention;

FIG. 13 illustrates electrical circuitry of a first inverter associated with the first time delay means pursuant to the present invention;

FIG. 14 illustrates electrical circuitry of a second inverter associated with the second time delay means pursuant to the present invention;

FIGS. 15 and 16 illustrate switching circuitry pursuant to the present invention; and

FIG. 17 illustrates feed-back switching means for overriding a power switch pursuant to the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, and more particularly to FIG. I, the present invention relates to a device or machine which is adapted to sever elongate strips of plastic or paper and the like into a plurality of stripsegments each having a selected discrete length. In this respect, an example of the elongate strip to be severed is that of a roll ofmicrofiche 20 wound upon a spool orcore 22 and having displayed thereonintelligence 24 separated by laterally extending borders 26. Theborder 26 are illustrated schematically in phantom and represent those portions of themicrofiche 20 which are to be severed by the device pursuant to the present invention. Extending along onelongitudinal edge 28 of themicrofiche 20 is a plurality of cut-reference indexing marks 30 which are separated from one another by respective ones of the laterally extendingborders 26 by a uniform distance from the latter.

FIG. 2 illustrates the device pursuant to the present invention. The device is generally denoted by thereference character 32 and is provided with ahousing 34 having an upper plate orplatform 36. At one end portion of theplatform 36 there is provided an enlarged cut-out 38 on each side of which extends one of a pair ofupstanding brackets 40. Each of thebrackets 40 is provided with a generallyU-shaped slot 42 which is adapted to receive and support freely anaxle portion 44 extending from respective ends of thespool 22 illustrated in FIG. 1.

Extending across the closed end of theenlarged cutout 38 is an upper idler guide roller 46 beneath which is disposed a lower idler guide roller 48. The rollers 46 and 48 have horizontal axes, respectively, and are freely journalled together in a pair ofupstanding brackets 49. Adjacent the rollers 46 and 48 is a pair ofidler guide rollers 50 which have respective vertical axes and are spaced from one another by an extent corresponding to the length of the rollers 46 and 48, this in turn corresponding to the lateral extent of themicrofiche 20 to be severed.

Extending forwardly from the vertical axisidler guide rollers 30 is a pair oftrack members 52 and 54 which are likewise spaced from one another by an extent corresponding to the lateral extent of themicrofiche 20. Thetrack member 54 is provided with an upperelongate slot 56 having a toothed rack 58 (FIG. 4) disposed along the upper rail thereof. Aprobe 60 which is adapted to be adjustably positioned both longitudinally and laterally of therack 58, and having a pinion gear 61 (FIG. 8) which meshes with thetoothed rack 58, is adjustably mounted on the slottedtrack member 54 for sensing or detecting the presence or absence of respective ones of the indexing marks 30 on themicrofiche 20.

A microfiche-feed assembly 62 is disposed at the forward end of thehousing 34 and is provided with anupper presser roller 64 and a lower drive roller 66 (FIG. 4). Theupper presser roller 64 is freely journalled in a spring-biased cantileveredbracket 68 which is pivotally arranged by means of a spring-hinge unit 70 (of conventional nature) upon a laterally extendingoverhead cross bar 72 spaced vertically above the upper plate orplatform 36. A tension-control knob 74 is threadedly mounted upon a threaded vertical shaft (not shown) which is fixed to thecross bar 72 and extends through an appropriate slot (not shown) formed in the cantileveredbracket 68.

Theoverhead cross bar 72 is mounted upon a pair ofsupports 76, 78 each having a respective cut out 80 conforming to the cross-section of thecross bar 72. Thecross bar 72 may, for example, be pivotally supported by means of a pin or the like (not shown) in the cut out 80 formed in thecross bar support 76. The opposite end of thecross bar 72 may be provided with a clamp-screw 82 which by conventional means (not shown) is adapted to tightly clamp that end of thecross bar 72 to thesupport 78 in the cut out 80 of the latter.

Extending laterally across the forward end of thehousing 34 and mounted upon theupper cross bar 72 is anupper cutting blade 84 of stationary nature. Thestationary blade 84 is presented with a cutting edge 85 (FIG. 4) which is spaced from theupper platform 36 by a distance corresponding to the thickness of themicrofiche 20. A lowerpivotal blade 86 is supported on abracket 88 having a pivotal axis 90 (FIG. 3). Thebracket 88 is pivotally journalled in respective overhangingportions 91 and 92 of the cross bar supports 76 and 78, respectively.Appropriate bearing assemblies 93 are provided in the overhangingportions 91 and 92 of thesupports 76 and 78, respectively, to permit theblade support bracket 88, and thereby thepivotal blade 86, to pivot relative to the upperstationary blade 84.

Preferably, thepivotal axis 90 of theblade support bracket 88 is tilted slightly such that the cutting edge portion of thepivotal blade 86 adjacent the overhangingportion 92 is slightly elevated relative to that of the cutting edge portion of thepivotal blade 86 adjacent the overhangingportion 91. However, it is to be understood that the at-rest position of the cutting edge portion of thepivotal blade 86, even at its highest end, is to be no higher than the upper surface of theupper platform 36 so that themicrofiche 20 can pass freely between theupper cutting blade 84 and the lowerpivotal blade 86.

Acontrol switch panel 94 is accessible upon theupper platform 36 to permit control over the various operations of thedevice 32 pursuant to the present invention. Likewise, a counter is disposed upon theupper platform 36 for indicating the number of cycles that thedevice 32 effects sequentially.

Referring now to FIG. 3, the underside of theplatform 36 supports an electrical circuit board orhousing 96 in which appropriate electrical circuitry, pursuant to the present invention, is disposed. Amotor unit 98 hav ing anoutput drive pulley 100 is likewise supported by the underside of theupper platform 36. The output drivepulley 100 is provided with a pair ofbelt grooves 102, 104. Associated with thebelt groove 102 is abelt 106 which is coupled with apulley 108 associated with a conventional clutch andspeed reducer assembly 110. The output of thespeed reducer 110 is coupled with ablade actuator 112 for effecting controlled pivotal movement of thelower blade 86 relative to the upperstationary blade 84.

Theblade actuator 112 may be of any conventional type, for example, a cam and cam follower arrangement or the like. However, it is preferred that theblade actuator 112 be provided with, as illustrated in FIG. 4, an eccentric or drive crank 114 coupled with the output of thespeed reducer 110, afirst link 116 pivotally associated with thecrank 114, and a second link 118 having one end thereof fixed to theblade support bracket 88 and the other end thereof pivotally associated with thelink 116. For these purposes, apin 120 couples thelink 116 to thecrank 114, whereas apin 112 couples thelink 116 with the link 118.

Referring again to FIG. 3, constrained within thebelt groove 104 of the output drivepulley 100, is asecond belt 124 which is associated with apulley 126. Thepulley 126 extendsfrom and is associated with a clutchbrake and anti-backlashgear drive assembly 128. Theassembly 128 is hingedly mounted on asupport 130 fixedly suspended from the underside of theplatform 36, and has a hinge axis 132 (shown in phantom). Aworm wheel 134 concealed by theassembly 128 and driven by a worm in the assembly 128 (to be described below) is provided with anaxle 136 upon which is concentrically mounted thedrive roller 66. Theplatform 36 is provided with a cut out 138 through which the periphery of thedrive roller 66 projects upwardly slightly for engagement with themicrofiche 20 as the latter is spring biased or pressed thereagainst by theupper presser roller 64. Anappropriate support bracket 140 is provided for the drive roller end of theaxle 136, whereas the opposite end of theaxle 136 is journalled in thesupport 130.

Referring now to FIG. 5, there is illustrated a schematic plan view of the clutch-brake and anti-backlashgear drive assembly 128. Theassembly 128 is provided with a housing l60'having a cut outportion 162 straddling thesupport 130 upon which theassembly 128 is hingedly mounted. Provided coaxially with thehinge axis 132 in the housing is a threadedbore 163 in which is threadedly constrained a socket ended setscrew 164. Thescrew 164 tightly bears against one of a pair ofball bearing assemblies 166 disposed in opposite ends of thesupport 130 and which define theaxis 132. Thehousing 160 is likewise provided with acavity 168 in which is disposed aclutch brake unit 170. Theunit 170 is provided with aflange 172 which is adapted to cover theend cavity 168 and is fastened to thehousing 160 by means ofrespective screws 174 or the like. Thehousing 160 is likewise provided with aninner cavity 175 of reduced width in which extends ajaw clamp piece 176 rotatably driven by the clutch-brake unit 170.

Also confined within theinner cavity 175 and separated from the clutch-brake unit 170 through the intermediary of apartition 177 or the like, is an antibacklashgear drive unit 178. Theunit 178 is provided with aworm 180 journalled freely insuitable bearings 182. In this respect, theworm 180 is axially hollow and is mounted upon acentral shaft 184 by means ofrespective set screws 186, thecentral shaft 184 extending through thebearings 182 in thepartition 177 into proximity with thejaw clamp piece 176 of theunit 170. A matingjaw clamp piece 188 is fastened to the end portion of thecentral shaft 184 by means of aset screw 190 or the like. Thejaw clamp piece 176 of theunit 170 is slightly axially separable from thejaw clamp piece 188 of theunit 178 and is adapted to mesh with and rotate thejaw clamp piece 188 when driven by theclutch brake unit 170.

Referring now to FIG. 6, theclutch brake unit 170 is provided with ahousing 192 upon which is fastened theflange 172 for securing theunit 170 to thehousing 160 of the clutch-brake and anti-backlashgear drive assembly 128. The clutch-brake unit 170 is provided within itshousing 192 with apole system 194 and acoil system 196 for generating a magnetic field. Adrive rotor 198 is rotatably journalled freely through the intermediary of a bearingassembly 200 in thehousing 192 and projects partially out of thehousing 192 so as to support thepulley 126 driven by thebelt 124. Thedrive rotor 198, although freely journalled, is prevented byspacers 199 from undergoing axial movement relative to a drivenrotor 202 mounted coaxially opposite and spaced from thedrive rotor 198. The drivenrotor 202 is rotatably journalled freely in thehousing 192 through the intermediary of a bearingassembly 204.

Fixedly secured to and extending coaxially from the drivenrotor 202 is ashaft extension 206. Theshaft extension 206 extends into and is received by abore 208 formed in thedrive rotor 198. The diameter of thebore 208 in thedrive rotor 198 is substantially larger than the diameter of theshaft extension 208 and, thus, theshaft extension 206 and driverotor 198 are slidably associated with another. It is, therefore, possible for thedrive rotor 198 to rotate relative to theshaft extension 206 of the drivenrotor 202 when the latter is braked.

Thedrive rotor 198 is provided with an open cavity 210, whereas the drivenrotor 202 is provided with a confrontingopen cavity 212. Acompression spring 214 is concentrically mounted upon theshaft extension 206 and bears at one of its opposite ends against aspacer 216 supported on theshaft extension 206, within the cavity 210 of thedrive rotor 198. Thespring 214 bears at its other end against aspacer 218 which is associated slidably with a ball bearing assembly 228 confined within thecavity 212 of the drivenrotor 202.

The drivenrotor 202 is provided with anouter shaft portion 222 which is freely journalled in and projects through theball bearing assembly 204. The extreme end of theouter shaft portion 222 supports thejaw clamp piece 176 which meshes with thejaw clamp piece 188 of theunit 178. In order to permit axial shifting of the drivenrotor 202 into and out of contact with thedrive rotor 198, theshaft extension 206 of the drivenrotor 202 terminates sufficiently remote from the closed end of thebore 208. In the absence of a mag netic field generated by thecoil 196, thespring 214 urges the drivenrotor 202 into contact with abrake pad 224. However, when a magnetic field is generated, the magnetic field overcomes the strength of thespring 214 and causes the drivenrotor 202 to approach, contact and rotate with thedrive rotor 198. Upon dissipation of the magnetic field, thespring 214 again urges the drivenrotor 202 against thebrake pad 224 to effect termination of the rotation of the drivenrotor 202, although thedrive rotor 198 continues to rotate by the continuously rotatingpulley 126. The axial spacing between thedrive rotor 198 and drivenrotor 202 is only slight. Therefore, thejaw clamp piece 176 fastened upon theouter shaft portion 222 of the drivenrotor 202 is only slightly axially separable from thejaw clamp piece 188 of theunit 178 and always remains in the meshing association therewith.

Referring now to FIG. 7, there is illustrated the antibacklashgear drive unit 178 in an inverted manner. Theunit 178 includes theaforementioned bracket support 130 upon which is hinged thehousing 160 for the entire clutch-brake and anti-backlashgear drive assembly 128. In this respect, thehousing 160 is hingedly supported at the lower end portion (upper end portion as seen in FIG. 7) of thesupport bracket 130 at the bearingassembly 166. Thesupport bracket 130 is likewise provided with a bearingassembly 242 which is coaxially mounted opposite a bearing assembly 244 in thesupport bracket 140 for thedrive roller 66. Theworm wheel 134 is mounted upon theworm wheel shaft 136 by means of acollar 248 integral with theworm wheel 134 and aset screw 250. The opposite end portions of theworm wheel shaft 136 are freely journalled in the bearingassemblies 242 and 244 of thesupport brackets 130 and 140, respectively. Thedrive roller 66 is press fit or otherwise conventionally secured to ahub 252. Thehub 252 is secured to theshaft 136 such as by means of setscrews 253.

The free end portion of thehousing 160, which is hingedly supported upon thesupport bracket 130, is provided with an aperture 254 beneath which is concentrically arranged a threadednut 256 of corresponding diameter, for supporting anadjustable thumb screw 258. Thethumb screw 258 is provided with anaperture 260 at one end thereof in which is constrained one end of atension spring 262. The opposite end of thespring 262 is secured to an aperture element or the like 264 provided in theupper platform 36.

Accordingly, thespring 262 acts to urge thehousing 160 pivotally toward theupper platform 36 such that theworm 180 is spring-biased against and intermeshes with the teeth of theworm wheel 134. This springbiased arrangement of theworm 180 andworm wheel 134 may be characterized as an anti-backlash gear drive system which obviates play and delimits clearance between the respective teeth of theworm 180 andworm wheel 184. Thus, whenever theworm 180 terminates rotation, theworm wheel 134 will be immediately responsive to the latter and without any backlash, theworm wheel 134 will likewise terminate its rotation.

Referring now to FIG. 8, there is illustrated theprobe 60 pursuant to the present invention. In this respect, theprobe 60 is adjustably supported both laterally and longitudinally of thetrack member 54, the latter having abase portion 280 affixed to theplatform 36 and separated horizontally from the vertical portion in which is provided therack 58. Thus, there is a clearance or space between thebase portion 280 and the vertical section which defines alower slot 282. The probe is provided with a light-detection housing 284 having avertical section 286, an upperhorizontal section 288 and a lowerhorizontal section 290. It is the lowerhorizontal section 290 which projects through the aforementionedlower slot 282 presented in thetrack member 54. The lowerhorizontal section 290 of thehousing 284 is provided with acentral bore 292 in which is contrained and press fit aplug 294 having an inclined end surface upon which amirror 296 is supported at an angle of substantially 45. Themirror 296 extends directly below anaperture 298 formed in the upper portion of the lowerhorizontal section 290. A photo-cell 300 fixedly projects into thecentral bore 292 for responding to light reflected by themirror 296. Respective electrical leads orterminals 302 extend externally from the photo-cell 300 to appropriate electrical circuitry as will be described below.

The upperhorizontal section 288 terminates in anend wall 304 in which is formed asemi-circular notch 306 for receiving and supporting ashaft 308 secured to thepinion 61. Thevertical section 286 is provided with anaperture 310 which is coaxially opposite thesemicircular notch 306 for receiving freely the end portion of theshaft 308. A pair of spacers are provided one on each side of thepinion 61 so as to maintain the latter in an axially fixed position relative to thevertical section 286 of thehousing 284.

A position-control andlamp support housing 314 is slidably mounted longitudinally but fixed laterally relative to thetrack member 54, thehousing 314 acting to support the light-detection housing 284 upon thetrack member 54. Thehousing 314 is provided with a threadedfront aperture 316 which communicates with aninner cavity 317. Threadedly fastened in theaperture 316 is aknob 318 having a threadedbody 320 which abuts axially against thevertical end wall 304 of the upperhorizontal section 288 of thehousing 284. Theknob 318 is provided with acentral bore 322 through which freely projects theshaft 308 for thepinion 61. The opposite end portion of thehousing 314 is provided with a pair ofend flanges 324 which conform in cross-section to the generally L-shaped cross-section of each of the portions of theupper slot 56 in thetrack member 54. It is theend flanges 324 which maintain the housing 3114 upon thetrack member 54 so that the housing is longitudinally slidable relative to theslot 56, but is restrained against lateral movement relative to the latter.

The lowermost portion of thehousing 314 is provided with acavity 326 in which is disposed a light source orlamp 328 having electrical leads orterminals 329 coupled with electrical circuitry as will be clarified below. Concentrically arranged upon theshaft 308 and extending externally of thehousing 314 is aspacer 330. Thespacer 330 is interposed between theknob 318 and apinion control knob 332. Thepinion control knob 332 is provided with acentral bore 334 for receiving theshaft 308, and a threaded opening extending radially of thebore 334 for receiving a threadedset screw 338 to tightly secure theknob 332 to the end of theshaft 308.

Accordingly, it is possible to accurately position theaperture 298 formed in the lowerhorizontal section 290 of thehousing 284 relative to thetrack member 54 for purposes of detecting selected ones of the indexing marks 30 on themicrofiche 20. In this respect, lateral adjustment of the light-detection housing 284 is effected simply by turning theknob 318. When theknob 318 is turned in one direction the end of the threadedbody portion 320 of theknob 318 will engage thevertical end wall 304 of the upperhorizontal section 288 of thehousing 284. This will cause thespacers 312 to transmit an axial force against thepinion 61, thereby causing thepinion 61 to shift laterally of therack 58. Thepinion 61 is only shifted slightly relative to therack 58 and, thus, the teeth of thepinion 61 always remain in intermeshing association with the teeth of therack 58. Shifting of thepinion 61 laterally of therack 58 also results in a shifting of theentire housing 284. Theaperture 298 formed in the lowerhorizontal section 290 of thehousing 284 is thereby shifted laterally relative to therack 58 so that its position will be precisely disposed below a selectedmark 30 on themicrofiche 20. Longitudinal adjustment of theprobe 60 is effected simply by turning theknob 332 which transmits rotary motion to theshaft 308 and thereby to thepinion 61. Rotation of thepinion 61 relative to therack 58 will affect a longitudinal excursion of theprobe 60 relative to therack 58.

CONTROL SYSTEM Referring now to FIG. 9, there is illustrated a diagrammatic block diagram of the electrical control system pursuant to the present invention. The control sys tem is associated with apower supply 400 and includes apower switch 402. Thepower supply 400 may, for example, have a 110 output. Thepower switch 402 is electrically coupled with themotor 98 which acts to drive both thespeed reducer assembly 110 and the clutch 170 which is associated with the anti-back-lashgear drive assembly 178. Apower transformer 404 is also electrically coupled with thepower switch 402 and acts to convert the AC power output into a 12 volt DC signal and a 35 volt DC signal. A pair of conventional rectifier, filter andvoltage regulator systems 406 and 408 respectively, are electrically coupled with the secondary windings of thepower transformer 404, thesystem 406 having a 12 volt output, and thesystem 408 having a 35 volt output.

Also electrically coupled with thepower supply 400 is aTRIAC 410 whose output is electrically coupled with themotor 98 and thepower transformer 404. TheTRlAC 410 has the capacity to override the condition of thepower switch 402 when the latter, for example, is open to maintain power to both themotor 98 and thepower transformer 404.

The electrical control system further includes a first self-deactivatingtime delay circuit 412 having an automaticmode start switch 414. Thetime delay circuit 412 is coupled with and governs the operation of theprobe 60 and, thus, at least in part may be characterized as a probe control means. Thetime delay circuit 412 is likewise electrically coupled with aninverter 416 which in turn is electrically coupled with a second selfdeactivatingtime delay circuit 418. Theinverter 416 acts to maintain the secondtime delay circuit 418 180 out of phase with the firsttime delay circuit 412. Thus, when thetime delay circuit 412 is in a condition of op eration, i.e., when thetime delay circuit 412 is in a con dition of delaying the operation of theprobe 60, theinverter 416 acts to render thetime delay circuit 418 inoperative.

The secondtime delay circuit 418 is electrically coupled with asecond inverter 420 which in turn is electrically coupled also with theprobe 60. Theinverter 420 functions to render theprobe 60 inoperative only when and only after the second time de1ay 418 has been activated for a selected interval and then deactivates itself.

Accordingly, when thefirst time delay 412 is activated by the automaticmode start switch 414, it renders theprobe 60 inoperative for a selected interval. During this interval, theinverter 416 renders thetime delay 418 inoperative and, thus, the output of theinverter 420 associated with theprobe 60 has no effect on the latter. However, after the selected interval of operation of thefirst time delay 412, e.g., after the latter deactivates itself, theprobe 60 is immediately activated. Likewise, theinverter 416 operates to activate thesecond time delay 410 for a second selected interval of reduced extent. However, theinverter 420 acts to maintain theprobe 60 operative during the operation of thesecond time delay 418. When thesecond time delay 418 is rendered inoperative, e.g., when the latter deactivates itself after the second selected interval of reduced extent, theinverter 420 acts to defeat or render inoperative theprobe 60.

The firsttime delay circuit 412 is also electrically coupled with a clutch feed SCR 422 (silicon control I rectifier) which acts to activate the clutch 170 associated with themicrofiche feed roller 66. Theprobe 60, on the other hand is electrically coupled with aclutch stop SCR 424 which acts to deactivate the clutch associated with themicrofiche feed roller 66. Moreover, theclutch feed SCR 422 and theclutch stop SCR 424 are operatively associated with one another such that when one is activated the other is deactivated. Thus, for example, when theclutch feed SCR 422 activates or engages the clutch 170, theclutch stop SCR 424 is deactivated. However, when theprobe 60 senses one of the reference indexing marks 30 on themicro fiche 20, it will activate theclutch stop SCR 424. The latter will in turn disengage thecllutch 170 and deactivate theclutch feed SCR 422.

A manualstop feed switch 426 is electrically coupled with theprobe 60 to effect a manual deactivation of the clutch 170, when desired, as is a second output from theinvertor 420 which is electrically coupled with theclutch stop SCR 424 to activate the latter and, thereby, terminate feeding themicrofiche 20 should theprobe 60 fail to sense one of the indexing marks 30 during the selected interval of reduced extent and operation of the secondtime delay circuit 418. Thus, should the entire selected period of reduced extent transpire so that thetime delay circuit 418 deactivates itself before theprobe 60 senses one of theindicia 30 on themicrofiche 20, then as a safeguard the second output of theconverter 420 activates theclutch stop SCR 424 to effect termination of the microfiche feed.

Theclutch feed SCR 422 is also electrically coupled with athird inverter 428 which in turn is electrically coupled with apulse generator 430. Thepulse generator 430 is electrically coupled with aTRlAC transformer 432 whose output or secondary winding is electrically coupled with theTRIAC 410. Theinverter 428,pulse generator 430 and theTRlAC transformer 432 may be characterized as a feed-back loop to theTRlAC 410 to override an opening of the:power switch 402 to continue advancement of themicrofiche 20 until theprobe 60 senses anext mark 30.

Theprobe 60 is also coupled with a start cutSCR 434 which is adapted to activate themicrofiche cutter blade 86 after theprobe 60 or stopclutch SCR 424 has effected termination of the feeding or advancement of themicrofiche 20. A stop cut switching means 436, preferably in the nature of a self-closing microswitch (although an SCR may be used likewise), is mechanically associated with a lobe (not shown) provided on thecrank 114 which drives thecutting blade 86. Thus, when theblade 86 has effected severing of themicrofiche strip 20, theswitch 436 acts to deactivate or disengage the clutch of thespeed reducer 110, thereby, deactivating thecutting blade 86. The stop cutswitch 436 is also electrically coupled with the firsttime delay circuit 412 so as to activate the latter and effect an automatic second and further cycling of the machine after the microfiche has been severed. Acycle counter coil 438 is electrically coupled with themicro-switch 436, the counter indicater associated with thecoil 438 being disposed on theplatform 36 and designated by thereference character 95 in FIG. 2.

Amanual cut switch 440 is interposed between and electrically coupled with theclutch feed SCR 422 and the start outSCR 434 to permit an operator, independently of theprobe 60, to effect a manual initiation of a cutting operation. Themanual cut switch 440 is electrically associated with theclutch feed SCR 422 in such a manner that when themanual cut switch 440 is closed, thecutting blade 86 will not be actuated until theclutch stop SCR 424 effects termination of the advancement of themicrofiche 20.

It will be understood, although not illustrated in FIG. 9, that the rectifier, filter andregulator system 408 whose output is 35 volts is electrically associated with theclutch feed SCR 422, theclutch stop SCR 424, the startclutch SCR 434, and thethird inverter 428. On the other hand, the rectifier, filter andregulator system 406 whose output is 12 volts, is electrically associated with theprobe 60, the firsttime delay circuit 412, thefirst inverter 416, the secondtime delay circuit 418, and thesecond inverter 420. For purposes of identification in FIG. 9, components associated with thesystem 408 are denoted by single asterisk. On the other hand, those components associated with thesystem 406 are denoted by a pair of asterisks.

PROBE AND PROBE AMPLIFIER- Referring now to FIG. 10, the electrical circuitry for theprobe 60 is illustrated within the box P (broken line), and the amplification circuitry for theprobe 60 is shown externally of the box P. The primary elements of theprobe 60 are thephotocell 300 and thelamp 328 associated with thephotocell 300. A double-pole, double-throw, switch SW-l is electrically coupled with thelamp 328 and may be moved between two extreme positions, namely the position in contact with the terminals T-l, as shown, and the position (not shown) in contact with the terminals T-2. A resistor R-l is electrically coupled withphotocell 300 in parallel therewith.

The nature of the circuitry of theprobe 60 is conventional, thephotocell 300 being adapted to distinguish either a darkly coloredindexing mark 30 on a lightly colored field of themicrofiche 20 or, alternatively, a lightly coloredindexing mark 30 on a darkly colored field of themicrofiche 20. The switch SW-l, when in a position in contact with the terminals T-I, is in a condition for distinguishing a darkly coloredindexing mark 30 relative to a lightly colored field of themicrofiche 20. When the switch SW-l is in contact with the terminals T-2, the photocell will distinguish a lightly coloredindexing mark 30 from a darkly colored field of themicrofiche 20.

A variable resistor R-2 (a potentiometer or the like) is electrically coupled in a series with a resistor R-3, the resistors R-2 and R-3 being in parallel with a preferably 0.1 microfarad capacitor G1 and a pair of Darlington transistor circuits Q-l and 0-2. The resistor R-2 controls the sensitivities of the circuits Q1 and Q-2. Each of the Darlington transistor circuits Q-l and 0-2 has an amplification factor of 10,000 or better and includes a pair of transistors whose collectors are commonly connected to one another. However, the emitter of one transistor of each pair is electrically coupled with the base of the second transistor of each pair, the emitter of the second transistor of each pair being electrically coupled to one another (to ground). Likewise, the collectors of each of the transistors of the circuit Q-l and each of the transistors of the circuit Q-2 are electrically coupled to one another. v

A normally closed switch SW-2 which corresponds to the manual stop feed switch 426 (FIG. 9) is electrically coupled with the commonly coupled emitters of the circuits 0-1 and Q-2 for purposes of deactivating the latter circuits in unison. The commonly coupled collec-. tors of the circuits 0-1 and 0-2 are electrically coupled in parallel with a resistor R-4 and a resistor R-S each having a rating of preferably 4.7K ohms. The resistor R-5 is electrically coupled with a base of a transistor Q-3 having an amplification factorin the range of, for example, -300, the collector of the transistor O-3 being electrically coupled with a terminal of thelamp 328. The emitter of the transistor Q-3 is electrically coupled with a pair of RC networks which govern the activation of theclutch stop SCR 424, and theSCR 434. One RC network, which is associated with theclutch stop SCR 424, includes a capacitor C2 and a resistor R-6 electrically coupled in parallel with one another, and a resistor R-S-and a diode D-l coupled in series with one another, and together in parallel with the capacitor C-2 and resistor R-6. The other RC network, which is associated with the start cutSCR 434, includes a capacitor C-3 and a resistor R-7 electrically coupled in parallel with one another, and a resistor R-9 and a diode D-2 coupled in series with one another and together in parallel with the resistor R-7 and capacitor C3. The capacitors C-2 and C-3 have, preferably, a rating of 5-15 microfarads, and the resistors R-6 and R-7 have, preferably, a rating of 5K ohms.

TIME DELAY CIRCUIT (412) Referring now to FIG. 11, thetime delay circuit 412 includes a pair of switches coupled in series with one another, namely a switch SW-3 mechanically associated with the micro-switch 436 (FIG. 9) which when opened and then closed will activate thetime delay circuit 412, and a switch SW-4 (the automaticmode start switch 414 denoted in FIG. 9).which when closed will permit thetime delay circuitry 412 to be continuously cyclically reactivated. A resistor R-l0 is coupled in series with the switch SW4 and is in turn electrically coupled in parallel with a resistor R-Il and a timecontrolling variable resistor R-12, the latter having a maximum rating of 10K ohms.

A 100-150 microfarad capacitor C4 is electrically coupled at one terminal with the variable resistor R-12, and at the other terminal with the resistor R-10 and a collector of a transistor 04 having an amplification factor of 150-300. The base of the transistor -4 is coupled with a resistor R-ll3 which is in turn electrically coupled in parallel with a resistor R-14 and a collector of a transistor 0-5 having an amplification factor of 150-300.

The base of the transistor 0-5 is electrically coupled with the capacitor C-4. The collector of the transistor 0-5 is likewise coupled in parallel with a K ohm resistor R- and a 5-15 microfarad capacitor C-5. A diode D3 is coupled with the resistor R-l5 and the capacitor C-5 and acts to channel current to theclutch feed SCR 422. The collector of the transistor 0-5 is also coupled with theinverter 416 as is the base of the transistor 0-4. The base of the transistor Q-4 and the collector of the transistor 0-5 are also commonly coupled with the base of the Darlington circuit 0-2 through the intermediary of a resistor R-40 and a diode D- coupled in series with one another.

Accordingly, the transistors 04 and 0-5 have an operative effect on the circuit 0-2 for determining when the transistor 0-3 will be fired to activate theclutch stop SCR 424 and the start cutSCR 434. When the transistor circuit 0-2 is on or activated by the transistors 0-4 and 0-5, the transistor 0-3 cannot activate theclutch stop SCR 424 and the start cutSCR 434. When the transistor circuit Q-2 is off or deactivated, then the transistor Q-3 can be activated to energize theSCR 424 and theSCR 434. However, the transistor 0-3 will not be activated until the transistor circuit 0-1 responds to the presence of anindexing mark 30 on themicrofiche 20 as sensed by thephotocell 300, and is in an off condition.

The transistors 0-4 and 0-5 operate 180 out of phase with one another (when one is off the other is on) and may be characterized as a mono-stable multivibrator whose output drives theclutch stop SCR 424 and the start cutSCR 434 and acts to defeat or inactivate temporarily the operation of theprobe 60 due to the control it exercises over the transistor circuitry Q-2. Thus, when the capacitor C-4 discharges, the transistor Q-5 is deactivated and the transistor 04 is activated to in turn activate the transistor 0-2. When 0-2 is activated, the timing cycle of thetime delay circuit 412 begins and prevents Q-3 from operating theclutch stop SCR 424 and the start cutSCR 434. When the capacitor C-4 is discharged, the transistor 05 is activated as is the transistor 0-3, and thereby theprobe 60.

TIME DELAY CIRCUIT (418) A secondtime delay circuit 418 is illustrated in FIG. 12 and includes a pair of transistors 06 and Q-7 each having an amplification factor of 150-300. The base of the transistor 0-6 is electrically coupled with the collector of the transistor 0-7 through the intermediary of a resistor RM. The base of the transistor 0-7 is electrically coupled with the collector of the transistor 0-6 through the intermediary of a 100-150 microfarad capacitor C-6. The capacitor 06 is electrically coupled with a time-controlling variable resistor R-l7 having a maximum rating of 10K ohms, and at its other terminal with a resistor R-18. A resistor R-l9 is electrically coupled in parallel with the resistor R-l7 at one side, and at the other side is electrically coupled in parallel with the resistor R-16 and the collector of the transistor 0-7. A 10K ohm resistor R-20 and a 5-15 microfarad capacitor C-7 are connected in parallel to the base of the transistor 0-6 and are together connected in series with INVERTER (416) Referring now to FIG. 13, there is illustrated theinverter 416 which is provided with a transistor Q-8 having an amplification factor of ISO-300. The base of the transistor Q-8 is coupled in parallel with a series arrangement of a resistor R-21 and a diode D5, and in parallel with a capacitor C8. The resistor R-2l is associated with the junction of the resistors R-l3 and R-l4 in FIG. 11. The collector of the transistor Q-8 is activated by the regulator of the system 406 (FIG. 9) through the intermediary of a resistor R-22. The collector of the transistor 0-8 is also associated with the capacitor C-7 (FIG. 12). In operation, theinverter 416 acts to maintain the secondtime delay circuit 418 180 out of phase with the firsttime delay circuit 412 through the intermediary of the transistor T-8. Thus, when the transistor 0-5 is inactivated so are the transistors 0-8 and 0-6, the latter inactivating the secondtime delay circuit 418. When the transistor 0-5 is activated, the transistors Q-8 and Q-6 are activated, the transistor Q-6 initiating the timing cycle of the secondtime delay circuit 418 which lasts until the capacitor C-6 is discharged.

INVERTER (420) Referring now to FIG. 14, there is illustrated asecond inverter circuit 420 which includes a transistor 0-9 having an amplification factor of -300. The base of the transistor Q-9 is coupled in parallel with a capacitor C-9 and with a series arrangement of a resistor R-23 and a diode D-6. The resistor R23 is associated with the junction of the collector of the transistor 0-7, the resistor R-l6 and the resistor R-19 (FIG. 12). The collector of the transistor 0-9 is powered by the regulator 406 (FIG. 9) and is coupled in parallel with both the latter and a resistor R-42 connected in series with theregulator 406. A resistor R-24 is coupled in parallel with the resistor R-42 and in series with a diode D-7 which is electrically coupled with the base of the transistor circuit 0-2 (FIG. 10) for controlling the latter independently of the transistors Q-4 and 0-5 in FIG. 11.

Also coupled with the collector of the transistor 0-9 are a resistor R-4l having a 10K ohm rating, and a capacitor C-40 having a 5-15 microfarad rating and connected in parallel with the resistor R-41. A diode D22 is connected to the resistor R41 and capacitor 040 and acts to channel current to theclutch stop SCR 424. Thus, when the transistor 0-9 is activated, namely when the second time delay circuit deactivates itself,

the transistor -9 will activate the transistor Q-2, thereby deactivating theprobe 60, and will activate theclutch stop SCR 424 to terminate advancement of thestrip 20. Since theclutch stop SCR 424 is coupled with the transistor 0-9 and not the start cutSCR 434, no cut will be effected upon termination of the advancement of the strip. Thus, the secondtime delay circuit 418 and thesecond inverter 420 act as a safeguard to terminate the feed of thestrip 20 if nomark 30 is sensed by theprobe 60 within the timing cycle of thedelay circuit 418. This will prevent a machine run-away.

CLUTCH FEED SCR (422) AND CLUTCH STOP SCR (424) Referring now to FIG. 15, theclutch feed SCR 422 and theclutch stop SCR 424, each having a minimum blocking potential of 400 volts and a circuit commutated turn-off time of a maximum of 50 microseconds, are each coupled with a capacitor 010 on opposite sides of the latter. The gate of theSCR 422 is electrically coupled with both the diode D-3 (FIG. 11) and a ground-channeling diode D-44 (FIG. 17). The gate of theSCR 424 is electrically coupled with the diode D-l (FIG. 10) and with the diode D-22 (FIG. 14).

One side of the capacitor C-10 is coupled in parallel with theSCR 422 and with a coil L-l of the clutch 170 (FIG. 6). The coil L-l is also coupled in parallel with a capacitor C-ll and a variable resistor R-25. The variable resistor R-25 is coupled in parallel with the regulator 408 (FIG. 9) and a resistor R-26. TheSCR 424 at one terminal is coupled in parallel with the capacitor C-10 and the resistor R-26. TheSCR 422 and theSCR 424 are associated with one another in what may be characterized as a flip-flop arrangement. Thus, when theclutch feed SCR 422 is activated, theSCR 424 is deactivated. On the other hand, when theclutch stop SCR 424 is activated, theclutch feed SCR 422 is deactivated. In this manner, the clutch coil L-l is alternately energized and deenergized by theSCR 422 and theSCR 424.

The manual cut switch 440 (FIG. 9) is also associated with theclutch feed SCR 422. In this respect, a 10K ohm resistor R-42 coupled in parallel with a -15 microfarad capacitor C-4l is coupled with theSCR 422 and a series arrangement of a diode D-42, a resistor R-43, a normally open manual switch SW-l0 (440) and the gate of the start cutSCR 434. When the switch SW40 is closed, theSCR 434 will be activated to initiate a cut, but only after theclutch stop SCR 424 is activated.

START CUT SCR (434) Referring now to FIG. 16, the start cutSCR 434 is coupled in parallel with a capacitor C-12 and the coil L-2 of the clutch associated with the speed reducer 110 (FIG. 3). The gate of theSCR 434 is coupled in parallel with the diode D-2 (FIG. to permit activation of theSCR 434 by the transistor Q-3 (FIG. 10), and also with the switch SW-lO (FIG. 15). A self-closing switch SW-S (switch 436 in FIG. 9) is electrically coupled in parallel with one side of the capacitor C-l2, a resistor R-27, a coil L-3 (coil 438) of thecounter 95 and with a capacitor C13. The other side of the resistor R-27 is coupled with a variable resistor R-28 which is connected in parallel with a capacitor G14 and the coil L-2 associated with the clutch of thespeed reducer 110. The resistor R-28 is also coupled with the regulator 408 (FIG. 9) to be powered by the latter.

Accordingly, when the transistor Q-3 (FIG. 10) is activated, the start cutSCR 434 is activated to power the coil L-2 which in turn engages the clutch of the speed reducer and actuates theblade 86 for severing thestrip 20. When the drive crank 114 associated with thecutting blade 86 effects one revolution, a lobe thereon (not shown) engages the switch SW-S and opens it. Upon opening of the switch SW-S, theSCR 434 is deactivated and the coil L-2 is deenergized thereby terminating power to thecutting blade 86. Each time the switch SW-S is opened, the coil L-3 associated with thecounter 95 is energized once to define a particular cutting count.

INVERTER (428), PULSE GENERATOR (430) AND TRIAC TRANSFORMER (432) Referring now to FIG. I7, there is illustrated a feedback circuit associated with the clutch feed SCR 422 (FIG. 15) for powering themotor 98 and thetransformer 404 until theprobe 60 senses one of theindicia 30 on the strip and terminates the advancement of thestrip 20. The feed-back loop, thus, acts independently of the power switch 402 (FIG. 9) and' continues to operate themotor 98 and thetransformer 404 even when thepower switch 402 is opened until theprobe 60 senses one of theindicia 30 onstrip 20.

In this respect, the feed-back loop comprises thethird inverter 428, thepulse generator 430 and theTRIAC'transformer 432, each denoted in FIG. 17 by a respective box in broken line. Theinverter 428 includes a transistor Q-10 having an amplification factor of -300 and whose base is coupled in parallel with a capacitor C-15, and a diode D-21 and a resistor R-29. The resistor R-29 is in series with the junction of the coil L1 and the capacitor 010 in FIG. 15. The collector of the transistor 0-10 is coupled with a resistor R-30 and is powered by the regulator 408 (FIG. 9).

Thepulse generator 430 includes a pair of transistors Q-ll and 0-12 each having an amplification factor of 150-300 and respective collectors which are coupled to opposite sides of a primary winding 432-P of thetransformer 432. The collectors of the transistors Q-ll and O-12 are also coupled with a pair of capacitors C-16 and C-l7, the capacitor C-16 being coupled with the base of the transistor Q-ll and the capacitor C-17 being coupled with the base of the transistor Q-12. The primary winding 432-P of thetransformer 432 is also electrically coupled with both the resistor R-30 and the collector of the transistor 0-10 of theinverter 428. One side of the secondary winding 432-S of thetransformer 432 is electrically coupled with the gate of theTRIAC 410, whereas the other side of the secondary winding 432-S is coupled with a primary terminal of theTRIAC 410. The latter said terminal of theTRIAC 410 and aropposite terminal of theTRIAC 410 are coupled in parallel with thepower switch 402, themotor 98, and the primary winding of thepower transformer 404. The pair of secondary windings of the power transformer are coupled, respectively, with thesystems 406 and 408. Thepower supply 400 is within a loop defined by theswitch 402 and themotor 98.

Accordingly, should theswitch 402 be closed, it shorts out and inactivates theTRIAC 410. However, should theswitch 402 be opened during a feeding cycle, theTRIAC 410 will override the openedswitch 402 and will continue to'power theclutch feed SCR 422 until amark 30 on thestrip 20 is sensed by theprobe 60, or until the second time delay circuit deactivates theclutch stop SCR 424.

A switch SW-12 is mechanically coupled with theswitch 402 and operates l80 out of phase with the latter. Thus, when theswitch 402 is opened, the switch SW-12 closes and directs current from a diode D-44 associated with the gate of theclutch feed SCR 422, and current from a diode D-45 associated with the gate of the start cutSCR 434, to ground. This will prevent the cutter from severing thestrip 20 when theswitch 402 is opened during a feeding cycle, but will permit the feeding cycle to continue until theprobe 60 senses amark 38 or is overriden by the secondtime delay circuit 418.

PARAMETERS It will be understood that certain components discussed above have preferred characteristics or parameters within the ranges defined. The other components may have a wide variety of characteristics, although not defined above, but which may be easily determined by being properly balanced with those defined, by artisans skilled in the art.

OPERATION OF THE MACHINE I A roll ofmicrofiche 20 is first disposed across theslot 38 in theupper platform 36 so that the opposite ends thereof rest in the brackets 41). The strip is partially unwound from the roll and is threaded between theguide rollers 48 and 49. The microfiche 21) is then pulled between thetracks 52 and 54 and threaded between theupper presser roller 64 and thelower drive roller 66. Themicrofiche 20 is then pushed forwardly so that it passes below the cutting edge of the upperstationary blade 84. Then one of the lateral borders 26 is aligned with the cutting edge of theupper blade 84, and the longitudinal position of theprobe 60 is adjusted by means of theknob 332 so that theaperture 298 beneath thelamp 328 coincides with the position of one of the indexing marks 30 which immediately trails thelateral border 26 oriented with the cutting edge of theupper blade 84. Then, by means of theknob 318 the lateral position of theaperture 298 beneath thelamp 328 is adjusted so that it also corresponds in position to whatever distance the first trailingindexing mark 30 is spaced from theedge 28 of themicrofiche 20.

Thepower switch 402 associated with themotor 98 and thepower transformer 404 is then closed to power each of the latter, as is the automatic start switch 414 (switch SW-4 in FIG. 11). Thetime delay circuit 412 and theclutch feed SCR 422 will thereby be actuated simultaneously. Upon actuation of thetime delay circuit 412, theprobe 60 will be rendered inoperative for a selected period as determined by the parameters of thetime delay circuit 412, e.g., the setting of the variable resistor R-12, so that it cannot respond to any intellignece which may lie along theedge 28 of themicrofiche 20 between themarks 30. During this initial inoperative period of theprobe 60, theclutch feed SCR 422 energizes the coil L-ll of the clutch 171) so that the clutch 170 is engaged and transmits power to theworm 180. The clutch 170 is engaged when thedrive rotor 198 is engaged by the axially shiftable drivenrotor 202 due to the excitation of thecoil 1% (L-1).

Because of the provision of the support housing which is pivotal relative to the bracket 138 (FIG. 7) and thespring 262 which urges the free end of thehousing 160 downwardly so that the worm 181) journaled in thehousing 160 is biased against theworm wheel 134, theworm wheel 134 is always immediately responsive to the worm 181). Thus, there is absent any play or backlash between the teeth of theworm wheel 134 and theworm 180. Accordingly, when theworm 180 is driven, theworm wheel 134 immediately responds and transmits rotation to thelower drive roller 66 which in turn frictionally advances themicro fiche 20 toward thecutters 84 and 86.

During the period of operation of the firsttime delay circuit 412, theinverter 416 renders the secondtime delay circuit 418 inoperative so that it cannot effect the condition of the probe 61). When thenext indexing mark 30 begins to closely approach theprobe 60, the firsttime delay circuit 412 deactivates itself pursuant to the setting of the resistor R-12 thereby activating theprobe 60. Theinverter 416 will in turn activate the secondtime delay circuit 418 which works through the intermediary of the inverter 4211 to permit operation of theprobe 60 for a selected period of lesser duration than the interval during which the probe 61) is rendered inoperative by the firsttime delay circuit 412.

Once theprobe 60 has been activated, theclutch stop SCR 424 is activated to thereby disengage the drivenrotor 282 of the clutch 171] from thedrive rotor 198. Thespring 214 urges the drivenrotor 202 into abutment with thebrake pad 224 to thereby terminate rotation of the driven rotor 2112. Upon the termination of rotation of the drivenrotor 282 "theworm 180 is likewise stopped. Again, because of the provision of the pivotal or hingedhousing 168 which supports theworm 180, and thespring 262 which urges theworm 180 into contact with theworm wheel 134, there is absent clearance between and backlash of theworm wheel 134 relative to theworm 180. This effects an immediate termination of the rotation of thelower drive roller 66. This in turn immediately stops the advancement of themicrofiche 20.

The start cutSCR 434 is then activated to in turn energize the coil L-2 associated with the clutch of the speed reducer 118. This will effect a single revolution of the drive crank 114 and an uplift of the lowerpivotal blade 86 relative to thestationary blade 84. Thestrip 28 is thereby severed. When theblade 86 returns to its at-rest position, as illustrated in FIG. 4, thecrank 114 is returned to its initial position, and the lobe (not shown) on thecrank 114 acts to open the self-closing micro-switch SW-S, e.g., the stop cutswitch 436 in FIG. 9, and the switch SIN-3 which are mechanically coupled with one another to open or close in unison. The switch SW-3', when closed (FIG. 11), acts to initiate a second and further cycle of the device by reactivating the firsttime delay circuitry 412.

If, for some reason, no indexing mark 31) appears within the period of operation of the secondtime delay circuit 418, for example the manufacturer of the microfiche failed to provide one of the indexing marks 30 in its proper position, then the secondtime delay circuit 418 through the intermediary of theinverter 420 deactivates the probe 611 and activates theclutch stop SCR 424. This in turn deenergizes the coil L-l of the clutch and effects termination of the rotation of theworm 180, thedrive worm wheel 134 and thelower driver roller 66. This prevents an uncontrolled runaway of the machine and permits operator inspection of themicrofiche 20.

A manual stop feed switch 426 (SW-2 in FIG. 10) is associated with the amplification circuitry of theprobe 60 to permit manual termination of the advancement of themicrofiche 20 when desired. The switch SW-2 when opened will deactivate both of the transistor circuits Q-l and -2 thereby activating the transistor Q-3 to in turn activate theclutch stop SCR 424. A switch SW-Il (FIG. is mechanically coupled with the switch SW-Z and operates 180 out of phase with the latter. Thus, when the switch SW-2 is opened, the switch SW-ll is closed thereby grounding the gate of the start outSCR 434 and preventing the latter from effecting a cut of the microfiche.

Likewise, amanual cut switch 440 is associated with the start outSCR 434 to permit a manual cutting operation, the switch 440 (FIG. 9) being associated with theclutch feed SCR 422 in a manner such that even when theswitch 440 is closed it will not effect a cutting operation until theclutch stop SCR 424 has effected termination of the advancement of themicrofiche 20, e.g., until theprobe 60 senses one of the indexing marks 30.

Having thus set forth the nature of the invention, it will be understood that numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the present invention which is for purposes of illustration only and not to be construed as a limitation of the invention.

What is claimed is:

1. In a machine for severing a strip into a plurality of strip segments of selected elongate extent, the strip having spaced reference indicia displayed thereon each at a selected distance from a corresponding position at which said strip is to be severed, the machine including cutting means for severing said strip, feed means for advancing said strip to said cutting means, probe means for sensing the presence of any of said indicia at a selected position behind said cutting means, first switching means operatively associated with said feed means for activating the latter, second switching means operatively associated with said probe means and said feed means for deactivating the latter when said probe means senses one of said indicia, third switching means operatively associated with said probe means and said cutting means for activating the latter when said probe means senses one of said indicia, and fourth switching means operatively associated with said cutting means for deactivating the latter when said strip is severed, an improvement comprising:

probe control means for selectively rendering said probe means alternately operative and inoperative at selected intervals during the operation of said feed means so that intelligence displayed on said strip other than and between said indicia will fail to be sensed by said probe means during the inoperative intervals of the latter, said probe control means including timing means operatively associated with said second switching means for activating the lat- 6 2. In a machine as claimed inclaim 1, wherein said probe control means includes a self-deactivating first time delay means operatively associated with said feed means and said probe means for deactivating the latter for a selected period during the operation of said feed means.

3. In a machine as claimed inclaim 2, wherein said first time delay means includes means for deactivating said probe means simultaneously upon activation of said feed means.

4. In a machine as claimed inclaim 2, wherein said timing means of said probe control means includes a self-deactivating second time delay means operatively associated with said first time delay means and said probe means for permitting said probe means to operate for a selected period of reduced extent during the operation of said feed means after said first time delay means is deactivated.

5. In a machine as claimed inclaim 4, including first inverter means interposed between and operatively associated with said first and second time delay means for alternately rendering said second time delay means inoperative and operative when said first time delay means is activated and deactivated, respectively.

6. In a machine as claimed inclaim 5, including second inverter means interposed between and operatively associated with said second time delay means and said probe means for deactivating the latter immediately after termination of said selected period of reduced extent of the operation of said second time delay means.

7. In a machine for severing a strip into a plurality of strip segments of selected elongate extent, the strip having spaced reference indicia displayed thereon each at a selected distance from a corresponding position at which said strip is to be severed, the machine including cutting means for severing said strip, feed means for advancing said strip to said cutting means, probe means for sensing the presence of any of said indicia at a selected position behind said cutting means, first switching means operatively associated with said feed means for activating the latter, second switching means operatively associated with said probe means and said feed means for deactivating the latter when said probe means senses one of said indicia, third switching means operatively associated with said probe means and said cutting means for activating the latter when said probe means senses one of said indicia, and fourth switching means operatively associated with said cutting means for deactivating the latter when said strip is severed, an improvement comprising:

a. probe control means for selectively rendering said probe means alternately operative and inoperative at selected intervals during the operation of said feed means so that intelligence displayed on said strip other than and between said indicia will fail to be sensed by said probe means during the inoperative intervals of the latter;

b. a manual power switch for powering said machine from an external electrical power supply; and

c. feed-back power means for by-passing said power switch when the latter is opened during advancement of said strip by said feed means to power the latter until said probe means next senses one of said indicia.

8. In a machine as claimed inclaim 7, wherein said feed-back power means includes a TRIAC, said external electrical power supply and power switch being coupled in series and together coupled in parallel with said TRIAC, and including a motor operatively associated with said feed means for driving the latter, said motor being coupled in parallel with said TRIAC and said in-series coupled external electrical power supply and power switch.

9. In a machine as claimed inclaim 3, wherein said probe means includes a photocell for responding to said indicia with a voltage drop, first transistor circuit means coupled with said photocell for responding to and being deactivated by a decrease in voltage across said photocell, second transistor circuit means coupled with said first transistor circuit means and said first time delay means for being deactivated by the latter when the latter is deactivated, and third transistor circuit means coupled with both said first and second transistor circuit means for being activated when both said first and second transistor circuit means are deactivated, said second and third switching means being coupled with said third transistor circuit means to be activated by the latter and, thereby, deactivate said feed means and activate said cutting means, respectively.

10. In a machine as claimed inclaim 9, wherein said first and second transistor circuit means each includes a pair of transistors whose collectors are all mutually coupled with one another, said third transistor circuit means including a single transistor whose base is coupled with the mutually coupled collectors of each of said pairs of transistors, the emitter of one transistor in each of said pairs being coupled with the base of the other transistor in each of said pairs, the emitter of the other transistor in one of said pairs being coupled with the emitter of the other transistor in the other of said pairs.

11. In a machine as claimed inclaim 10, including a light source operatively associated with said photocell, said single transistor having a collector coupled with a terminal of said light source, and an emitter coupled with saidsecond and third switching means.

12. In a machine as claimed inclaim 11, including a first resistor and a first capacitor coupled in parallel with one another and together in a series with a terminal of said second switching means, a second resistor and a second capacitor coupled in parallel with one another and together in series with a terminal of said third switching means, and a third capacitor coupled in parallel with said first transistor circuit means and said photocell.

13. In a machine as claimed inclaim 9, wherein said first time delay means includes a pair of transistors, and a time-controlling variable resistor having a pair of opposite terminals, one of said terminals being coupled with a base of one of said transistors, the other of said terminals being coupled with a collector of each of said transistors and with a base of the other transistor.

14. In a machine as claimed inclaim 13, including a capacitor interposed between and coupled with the base of said one of said transistors and with the collector of said other of said transistors.

15. In a machine as claimed inclaim 14, wherein the collector of said one of said transistors and the base of said other of said transistors are coupled with said second transistor circuit means and with said first switching means.

16. In a machine as claimed inclaim 15, including a resistor and a further capacitor coupled in parallel with one another and together in series with and between said collector of said one of said transistors and said first switching means.

17. In a machine as claimed inclaim 16, including a self-closing switch coupled at one terminal with an emitter of each of said transistors, and at its other terminal with the collector of said other of said transistors and through the intermediary of the first said capacitor to the base of said one of said transistors, said switch when opened and then closed acting to activate said other of said transistors and, thereby, initiate a timing cycle.

18. In a machine as claimed inclaim 13, wherein said probe control means includes a self-deactivating second time delay means operatively associated with said first time delay means and said probe means for permitting said probe means to operate for a selected period of reduced extent during the operation of said feed means after said first time delay means including a second pair of transistors, and a second time controlling variable resistor having a pair of opposite terminals, one of the latter said terminals being coupled with a base of one of said transistors of the latter said pair, the other of the latter said terminals being coupled with a collector of each of said transistors of the latter said pair and with a base of the other transistor of the latter said pair.

19. In a machine as claimed inclaim 9, wherein each of said first and second switching means includes a respective silicon control rectifier, each of said rectifiers having a pair of terminals similar to the other and a gate, one terminal of one of said rectifiers which corresponds to one terminal of the other rectifier being coupled with the latter through the intermediary of a capacitor, the other terminal of each of said rectifiers being coupled with one another, the gate of said one said rectifiers being coupled with said third transistor circuit means, the gate of said other rectifier being coupled with said first time delay means, and including a clutch coil for generating a magnetic field, said clutch coil having a pair of opposite terminals coupled in parallel with said capacitor.

20. In a machine as claimed inclaim 19, wherein said third switching means includes a silicon control rectifier, and said fourth switching means includes a mechanically actuable switch, the latter said rectifier including a pair of terminals and a gate, one of the latter said terminals being coupled with one terminal of the latter said switch through theintermediary of a further capacitor, the other terminal of the latter said rectifier and of the latter said switch being coupled with one another, said gate of the latter said rectifier being coupled with said third transistor circuit means, and including a further clutch coil for generating a magnetic field, the latter said clutch coil being coupled in parallel with the latter said capacitor.

21. In a machine for severing a strip into a plurality of strip segments of selected elongate extent, the strip having spaced reference indicia displayed thereon each at a selected distance from a corresponding position at which said strip is to be severed, the machine including cutting means for severing said strip, feed means for advancing said strip to said cutting means, probe means for sensing the presence of any of said indicia at a selected position behind said cutting means, first switching means operatively associated with said feed means for activating the latter, second switching means operatively associated with said probe means and said feed means for deactivating the latter when said probe means senses one of said indicia, third switching means operatively associated with said probe means and said cutting means for activating the latter when said probe means senses one of said indicia, and fourth switching means operatively associated with said cutting means for deactivating the latter when said strip is severed, an improvement comprising:

probe control means for selectively rendering said probe means alternately operative and inoperative at selected intervals during the operation of said feed means so that intelligence displayed on said strip other than and between said indicia will fail to be sensed by said probe means during the inoperative intervals of the latter, said probe control means including a selfdeactivating first time delay means operatively associated with said feed means and said probe means for deactivating the latter for a selected period during the operation of said feed means, and

a self-deactivating second time delay means operatively associated with said first time delay means and said probe means for permitting said probe means to operate for a selected period of reduced extent during the operation of said feed means after said first time delay means is deactivated;

first inverter means interposed between and operasecond inverter means interposed between and operatively associated with said second time delay means and said probe means for rendering each out of phase with the other and, thereby, operating said probe means during the time-delaying operation of said second time delay means.

Claims (21)

1. In a machine for severing a strip into a plurality of strip segments of selected elongate extent, the strip having spaced reference indicia displayed thereon each at a selected distance from a corresponding position at which said strip is to be severed, the machine including cutting means for severing said strip, feed means for advancing said strip to said cutting means, probe means for sensing the presence of any of said indicia at a selected position behind said cutting means, first switching means operatively associated with said feed means for activating the latter, second switching means operatively associated with said probe means and said feed means for deactivating the latter when said probe means senses one of said indicia, third switching means operatively associated with said probe means and said cutting means for activating the latter when said probe means senses one of said indicia, and fourth switching means operatively associated with said cutting means for deactivating the latter when said strip is severed, an improvement comprising: probe control means for selectively rendering said probe means alternately operative and inoperative at selected intervals during the operation of said feed means so that intelligence displayed on said strip other than and between said indicia will fail to be sensed by said probe means during the inoperative intervals of the latter, said probe control means including timing means operatively associated with said second switching means for activating the latter to deactivate said feed means when said probe means fails to sense one of said indicia within a selected time period during its operative interval.

2. In a machine as claimed in claim 1, wherein said probe control means includes a self-deactivating first time delay means operatively associated with said feed means and said probe means for deactivating the latter for a selected period during the operation of said feed means.

3. In a machine as claimed in claim 2, wherein said first time delay means includes means for deactivating said probe means simultaneously upon activation of said feed means.

4. In a machine as claimed in claim 2, wherein said timing means of said probe control means includes a self-deactivating second time delay means operatively associated with said first time delay means and said probe means for permitting said probe means to operate for a selected period of reduced extent during the operation of said feed means after said first time delay means is deactivated.

5. In a machine as claimed in claim 4, including first inverter means interposed between and operatively associated with said first and second time delay means for alternately rendering said second time delay means inoperative and operative when said first time delay means is activated and deactivated, respectively.

6. In a machine as claimed in claim 5, including second inverter means interposed between and operatively associated with said second time delay means and said probe means for deactivating the latter immediately after termination of said selected period of reduced extent of the operation of said second time delay means.

7. In a machine for severing a strip into a plurality of strip segments of selected elongate extent, the strip having spaced reference indicia displayed thereon each at a selected distance from a corresponding position at which said strip is to be severed, the machine including cutting means for severing said strip, feed means for advancing said strip to said cutting means, probe means for sensing the presence of any of said indicia at a selected position behind said cutting means, first switching means operatively associated with said feed means for activating the latter, second switching means operatively associated with said probe means and said feed means for deactivating the latter when said probe means senses one of said indicia, third switching means operatively associated with said probe means and said cutting means for activating the latter when said probe means senses one of said indicia, and fourth switching means operatively associated with said cutting means for deactivating the latter when said strip is severed, an improvement comprising: a. probe control means for selectively rendering said probe means alternately operative and inoperative at selected intervals during the operation of said feed means so that intelligence displayed on said strip other than and between said indicia will fail to be sensed by said probe means during the inoperative intervals of the latter; b. a manual power switch for powering said machine from an external electrical power supply; and c. feed-back power means for by-passing said power switch when the latter is opened during advancement of said strip by said feed means to power the latter until said probe means next senses one of said indicia.

8. In a machine as claimed in claim 7, wherein said feed-back power means includes a TRIAC, said external electrical power supply and power switch being coupled in series and together coupled in parallel with said TRIAC, and including a motor operatively associated with said feed means for driving the latter, said motor being coupled in parallel with said TRIAC and said in-series coupled external electrical power supply and power switch.

9. In a machine as claimed in claim 3, wherein said probe means includes a photocell for responding to said indicia with a voltage drop, first transistor circuit means coupled with said photocell for responding to and being deactivated by a decrease in voltage across said photocell, second transistor circuit means coupled with said first transistor circuit means and said first time delay means for being deactivated by the latter when the latter is deactivated, and third transistor circuit means coupled with both said first and second transistor circuit means for being activated when both said first and second transistor circuit means are deactivated, said second and third switching means being coupled with said third transistor circuit means to be activated by the latter and, thereby, deactivate said feed means and activate said cutting means, respectively.

10. In a machine as claimed in claim 9, wherein said first and second transistor circuit means each includes a pair of transistors whose collectors are all mutually coupled with one another, said third transistor circuit means including a single transistor whose base is coupled with the mutually coupled collectors of each of said pairs of transistors, the emitter of one transistor in each of said pairs being coupled with the base of the other transistor in each of said pairs, the emitter of the other transistor in one of said pairs being coupled with the emitter of the other transistor in the other of said pairs.

11. In a machine as claimed in claim 10, including a light source operatively associated with said photocell, said single transistor having a Collector coupled with a terminal of said light source, and an emitter coupled with said second and third switching means.

12. In a machine as claimed in claim 11, including a first resistor and a first capacitor coupled in parallel with one another and together in a series with a terminal of said second switching means, a second resistor and a second capacitor coupled in parallel with one another and together in series with a terminal of said third switching means, and a third capacitor coupled in parallel with said first transistor circuit means and said photocell.

13. In a machine as claimed in claim 9, wherein said first time delay means includes a pair of transistors, and a time-controlling variable resistor having a pair of opposite terminals, one of said terminals being coupled with a base of one of said transistors, the other of said terminals being coupled with a collector of each of said transistors and with a base of the other transistor.

14. In a machine as claimed in claim 13, including a capacitor interposed between and coupled with the base of said one of said transistors and with the collector of said other of said transistors.

15. In a machine as claimed in claim 14, wherein the collector of said one of said transistors and the base of said other of said transistors are coupled with said second transistor circuit means and with said first switching means.

16. In a machine as claimed in claim 15, including a resistor and a further capacitor coupled in parallel with one another and together in series with and between said collector of said one of said transistors and said first switching means.

17. In a machine as claimed in claim 16, including a self-closing switch coupled at one terminal with an emitter of each of said transistors, and at its other terminal with the collector of said other of said transistors and through the intermediary of the first said capacitor to the base of said one of said transistors, said switch when opened and then closed acting to activate said other of said transistors and, thereby, initiate a timing cycle.

18. In a machine as claimed in claim 13, wherein said probe control means includes a self-deactivating second time delay means operatively associated with said first time delay means and said probe means for permitting said probe means to operate for a selected period of reduced extent during the operation of said feed means after said first time delay means including a second pair of transistors, and a second time controlling variable resistor having a pair of opposite terminals, one of the latter said terminals being coupled with a base of one of said transistors of the latter said pair, the other of the latter said terminals being coupled with a collector of each of said transistors of the latter said pair and with a base of the other transistor of the latter said pair.

19. In a machine as claimed in claim 9, wherein each of said first and second switching means includes a respective silicon control rectifier, each of said rectifiers having a pair of terminals similar to the other and a gate, one terminal of one of said rectifiers which corresponds to one terminal of the other rectifier being coupled with the latter through the intermediary of a capacitor, the other terminal of each of said rectifiers being coupled with one another, the gate of said one said rectifiers being coupled with said third transistor circuit means, the gate of said other rectifier being coupled with said first time delay means, and including a clutch coil for generating a magnetic field, said clutch coil having a pair of opposite terminals coupled in parallel with said capacitor.

20. In a machine as claimed in claim 19, wherein said third switching means includes a silicon control rectifier, and said fourth switching means includes a mechanically actuable switch, the latter said rectifier including a pair of terminals and a gate, one of the latter said terminals being coupled with one terminal of the latter said switch thRough the intermediary of a further capacitor, the other terminal of the latter said rectifier and of the latter said switch being coupled with one another, said gate of the latter said rectifier being coupled with said third transistor circuit means, and including a further clutch coil for generating a magnetic field, the latter said clutch coil being coupled in parallel with the latter said capacitor.

21. In a machine for severing a strip into a plurality of strip segments of selected elongate extent, the strip having spaced reference indicia displayed thereon each at a selected distance from a corresponding position at which said strip is to be severed, the machine including cutting means for severing said strip, feed means for advancing said strip to said cutting means, probe means for sensing the presence of any of said indicia at a selected position behind said cutting means, first switching means operatively associated with said feed means for activating the latter, second switching means operatively associated with said probe means and said feed means for deactivating the latter when said probe means senses one of said indicia, third switching means operatively associated with said probe means and said cutting means for activating the latter when said probe means senses one of said indicia, and fourth switching means operatively associated with said cutting means for deactivating the latter when said strip is severed, an improvement comprising: probe control means for selectively rendering said probe means alternately operative and inoperative at selected intervals during the operation of said feed means so that intelligence displayed on said strip other than and between said indicia will fail to be sensed by said probe means during the inoperative intervals of the latter, said probe control means including a self-deactivating first time delay means operatively associated with said feed means and said probe means for deactivating the latter for a selected period during the operation of said feed means, and a self-deactivating second time delay means operatively associated with said first time delay means and said probe means for permitting said probe means to operate for a selected period of reduced extent during the operation of said feed means after said first time delay means is deactivated; first inverter means interposed between and operatively associated with said first and second time delay means for rendering each 180* out of phase with the other and, thereby, alternately rendering said second time delay means inoperative and operative when said first time delay means is activated and deactivated, respectively; and second inverter means interposed between and operatively associated with said second time delay means and said probe means for rendering each 180* out of phase with the other and, thereby, operating said probe means during the time-delaying operation of said second time delay means.

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