US3370690A - Sheet handler-stripper - Google Patents

Description

Feb. 27, 1968 R. R. SEEDORF SHEET HANDLER-STRIPPER Filed Oct. 21, 1965 4 Sheets-Sheet 1 Feb. 27, 1968 R. R. SEEDORF SHEET HANDLERSTRIPPER 4 Sheets-Sheet 2 Filed Oct. 21, 1965 5 Elllllflllllllll Feb. 27, 1968 R. R. SEEDORF 3,370,690

SHEET HANDLERSTRIPPER Filed Oct. 21, 1965 4 Sheets-Sheet 3 Feb. 27, 1968 R. R. SEEDORF SHEET HANDLER-STRIPPER 4 Sheets-Sheet 4 Filed Oct. 21, 1965 N MWN United States Patent O 3,370,690 SHEET HANDLER-STRIPPER Robert R. Seedorf, Barrington,'lll., assignor to The Roy M. Mofiitt Company, a corporation of Illinois Filed Oct. 21, 1965, Ser. No. 500,074 13 Claims. (Cl. 198-20) ABSTRACT OF THE DISCLOSURE A sheet handler and stripper for use with a sheet dryer including a base having a shaft movably mounted thereon, a plurality of tubes communicating with a vacuum source secured to the shaft and having an opening along one side thereof, a perforated belt for each of the tubes having a run thereof substantially in contact with the opening therein, means for selectively driving the belts, and sensing means for operating the drive means for a predetermined time after a sheet holder of the sheet dryer passes the belt.

Background of the invention It is conventional in sheet dryers to provide a conveyor with wickets for supporting sheets traveling through the dryer. Use of such wicket conveyors in sheet dryers has solved many of the problems attendant the drying of sheets as the wickets provide a generally satisfactory support for the sheets as they are passed through the dryer. As is well known, in a typical wicket conveyor, the wickets are supported on the conveyor at an angle in the range of about 45 to about 75 and are closely placed along the length thereof. This construction maximizes the number of sheets that can be dried during any given period of operation of the dryer, and accordingly, is a very practical construction from the standpoint of equipment size and the like.

However, such wicket conveyor constructions present various sheet handling problems in the loading and unloading of the wicket conveyor. In the case of loading the wicket conveyor, the problem is easily solved by feeding the sheets to be dried to the space between adjacent wickets by a rapidly moving conveyor, which method of feeding is well known in the art. In the case of unloading or stripping sheets from such wicket conveyors, the problem is not susceptible to so easy a solution. Many such wicket conveyors include on the end of each wicket remote from the point of attachment of the wicket to the conveyor, a transverse hook-like member which serves as a support to limit movement of the sheet on the wicket during such times as the wicket projects downwardly from the dryer conveyor. In such a case, use of a continuously moving conveyor as a stripper to engage the sheet upon the wicket and remove it from the space between that wicket and the adjacent wicket, would drive the sheet into the transverse or hooklike portion to be hung-up thereon and defy unloading or be crumpled thereagainst and ruin the sheet.

Summary of the invention The principal object of the invention is to provide a new and improved sheet handler and stripper for sheet dryers of the wicket-type.

More specifically, it is an object of the invention to provide stripping means for unloading sheets from wickets such that the sheets will not be crushed against hook-like end portions on the wickets.

Another object of the invention is the provision of such a stripping means for unloading sheet dryers of the wicket type wherein conveying means are intermittently operable for a predetermined time period whereby the 3,376,699 Patented Feb. 27, 1968 sheet to be unloaded may engage the conveying means while the latter is temporarily maintained stationary to be held thereby while the wicket conveyor moves the hook-like end portion of the wicket away from the edge of the sheet whereupon the conveying means is actuated to remove the sheet from the space between the wickets.

Another object of the invention is the provision of such a sheet handling and stripping device for use with wicket conveyors wherein the sheet to be unloaded from the wicket conveyor is subjected to a vacuum to draw the sheet against the conveying means.

Another object of the invention is the provision of a sheet handler and stripping device for use with sheet dryers of the wicket type wherein the sheet handler and stripper is responsive to jamming of sheets on the wicket conveyor or the sheet handler and stripper and includes means responsive to such jamming for terminating the operation of the wicket conveyor and other equipment, such as a printer, used therewith.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings.

Description of the drawings FIGURE 1 is a side elevation of a form of the invention used in conjunction with a sheet dryer of the wicket yp FIGURE 2 is an enlarged side elevation thereof;

FIGURE 3 is a side elevation thereof with certain of the belts broken away;

FIGURE 4 is'an expanded view of a vacuum manifold arrangement;

FIGURE 5 is a side elevation of a fragment of a portion of a control therefor;

FIGURE 6 is a fragmentary vertical section taken approximately along the line 6-6 of FIGURE 5; and

FIGURE 7 is a combined schematic and block diagram of a control circuit.

Detailed description An exemplary form of the invention, generally designated 10, is shown in FIGURE 1 in conjunction with a sheet dryer of the wicket type, generally designated 12. Thesheet dryer 12 may be conventional or may be of the type disclosed in applicants copending application Ser. No. 140,052, filed Sept. 22, 1961, now Patent No. 3,192,648, the details of which are herein incorporated by reference. Thesheet dryer 12 includes a drying chamber, generally designated 14 through which a suitable endless conveyor is driven by a drive train connected to the drive of a printer 136 or by an auxiliary drive shown schematically at 134 in FIG. 7. The conveyor mounts a plurality ofwickets 16 having transverse or hook-like ends 17, and may be guided by conventional means such that thewickets 16 follow the path of travel indicated at 18.

Preferably, for purposes that will be seen hereinafter, the ends of the conveyor are guided such that at some point during the reversal of the direction of eachwicket 16, eachwicket 16 will fall away from the followingwicket 16. In the embodiment of thesheet dryer 12 shown in FIG. 1, it is intended that the conveyor supporting thewickets 16 be driven in a generally counterclockwise direction. As a result of the conveyor being driven in such a direction, it will be appreciated that the falling away occurrence described above will inherently take place at the left-hand end 20 of thesheet dryer 12 as thewickets 16 are conveyed from the upper run of the conveyor to the lower run thereof. However, at the right-hand end 22 of thesheet dryer 12, thewickets 16 are moved from the lower run of the conveyor to the upper run thereof and such action will not inherently occur, Accordingly, the wickets are mounted on the conveyor in an angular relation somewhat less than 90 and the conveyor is made to undergo a rather abrupt change of direction. As a result of such construction, during about the first portion of the rotation of eachwicket 16 at the right-hand end 22 of thesheet dryer 12, eachwicket 16 will fall away in a downward arcuate path from the followingwicket 16, as shown in FIG. 1, and subsequently be further rotated and elevated to the upper run of the conveyor. Additionally, theenclosure 14 of thesheet dryer 12 is provided with suitable ducts and blowers 24 to circulate drying air within theenclosure 14 to dry sheets carried by thewicket 16. The sheets to be dried may be fed to thewicket 16 by conventional means at the right-hand end 22 of thesheet dryer 12 as from a conventional printer, shown schematically at 135 in FIG. 7.

The sheet handler and stripper 10 for removing dried sheets from thewicket 16 may be placed adjacent the right-hand end 22 of thesheet dryer 12, as shown in FIG. 1, or if desired may be placed adjacent the left-hand end of thesheet dryer 12, depending on the processing requirements for any given type of sheet.

Turning now to FIGURES 2 and 3, there is seen a more detailed view of the sheet handler stripper made according to the invention. Generally, the invention includes a base which may be portable and mounts a plurality of movable arms bearing intermittently movable sheet engaging belts provided with vacuum means for holding sheets on the belts and wicket sensing means for operating the belts in a predetermined manner to unload the wickets. More specifically, thesheet handler stripper 10 includes abase 26 which is mounted on a plurality of rollers orcasters 28 so as to provide a portable structure. Such a construction is particularly advantageous insofar as it lends flexibility to the processing operation by simplifying movement of thesheet handler stripper 10 to either of theends 20 or 22 of thesheet dryer 12. If desired, thebase 26 may include suitable means for changing its height relative to the surface on which it is supported. On the upper end of thebase 26 there is mounted a pillow block bearing 30 and a flange block bearing 31 which rotatably supports ashaft 32. Theshaft 32 has ahollow center 34 and a plurality ofnotches 36 in its periphery which communicate with thehollow center 34. Theshaft 32 is threaded, as at 37, about the area of eachnotch 36. A hollow rectangular saddle member 38 is mounted on an internally threaded sleeve 39. Each of thenotches 36 is arranged to be surrounded by a sleeve 39 such that fluid communications may be established between thehollow center 34 of theshaft 32 of the hollow saddle of the saddle member 38. The threaded relationship between theshaft 32 and the sleeve 39 provides a fluid connection. Each mounting member 38 is received in a fluid tight relation within a rectangular opening 49 in the bottom surface of arectangular tube 42. Eachtube 42 has its ends sealed (as at 44 in FIG, 3) and includes a flatupper surface 46 having anelongated slot 48 therein which communicates with the center of thetube 42.

As best seen in FIGURES 2 and 3, abifurcated yoke 56 is secured to the outer end of each of thetubes 42. Each of the bifurcatedyokes 56 supports arotatable sheave 52 such that theflat surface 46 of eachtube 42 is essentially tangential to one point on the driving surface of thesheave 52.

Theouter tubes 42 also support adjacent their lowermost ends, a pair of generally downwardly projectingplates 54. If desired additional plates may be secured to theother tube 42. Theplates 54, in turn, journal arotatable shaft 56 on which is mounted a plurality ofsheaves 58. Thesheaves 58 and theshaft 56 are rotatably supported on theend plates 54 such that theflat surface 46 of eachtube 42 is essentially tangential to a point on the driving surface of eachsheave 58.

As may be seen in FIG. 3, eachsheave 58 is aligned with atube 42 and the sheave supported thereon. Eachsheave 58 and sheave 59 are surrounded by anendless belt 60 having a plurality of apertures 62 therein. As a result of the construction just described, one .runof eachbelt 60 will be substantially in contact with theflat surface 46 of eachtube 42 and the apertures 62 in each belt.

periodically will be in fluid communication with theelongated slot 48 and ultimately thehollow center 34 of theshaft 32. Thehollow center 34 of theshaft 32 communicates through suitable means, such as a rotary union, not shown, with a vacuum pump or centrifugal blower 64 mounted on thebase 10. The blower 64 is driven by asuitable motor 66 and is mounted such that its. intake is arranged coaxially with theshaft 32. By virtue of the foregoing construction, it will be obvious that when themotor 66 is energized, the blower 64 will evacuate/thehollow center 34 of theshaft 32 and thetubes 42. As a result, a region of low pressure or partial vacuum will be present along the run of thebelts 60 having the apertures 62 therein communicating with theslot 48 in thetubes 42 to hold sheets engaged by thebelts 66 against the latter.

Theshaft 32 also includes a step portion which is formed by the reception of the smaller,-solid shaft 68 within thehollow center 34 at the end of theshaft 32. The relationship of theshaft 68 and theshaft 32 is such that the former element serves to seal one end of theshaft 32. Additionally, theshaft 68 provides an extension of theshaft 34 which is received within thepillow block 30 as seen in FIG. 3. About the portion of theshaft 68 intermediate theshaft 32 and thepillow block 30, there is mounted a 3-groove sheave 71 havinggrooves 72 and 74 and which is rotatable relative to theshaft 68. The groove 72 is aligned with a sheave 7 6 secured to theshaft 56 and with asuitable idler assembly 78. A belt is trained:

about the groove '72 and thesheave 76 and theidler assembly 78 such that when the sheave 71 is driven, shaft 55 and thebelts 60 will be driven. Thegroove 74 is aligned with asheave 82 and anidler assembly 84. Thesheave 82 is mounted on the output shaft of adrive motor 88, Which is mounted on the base26. A conventional,

magnetic clutch 89 is included in themotor assemblage 88. Abelt 86 is trained through thegroove 74 and about thesheave 82 and theidler assembly 84 such that when thesheave 82 is driven, the sheave 71 will also be driven.

Themotor 88 and the magnetic clutch 89 operate to cause thebelts 60 to undergo intermittentmovement to unload sheets from thewickets 16 through intermittent energization of the clutch 89 in response to the passing of thewickets 16 by thebelts 60. By means of an L-shapedbracket 90 secured to theshaft 32 adjacent one end thereof, there is mounted asensor 92 which is operative to energize the magnetic clutch 89 to ultimately drive the sheave 72 and effect movement of the belt60. Thesensor 92 detects the present of eachwicket 16 as it passes thereby. To accomplish this function, thesensor 92 may comprise a microswitch, an electric eye or a magnetic proximity detector. Thesensor 92 is placeda distance from the run of thebelts 60 which are substantially in contact with theflat surface 46 of thetubes 42, a distance at least equal to the length of thetransverse end portions 17 of thewickets 16 such that the magnetic clutch 89 is actuated only after the wickettransverse end portions 17 have passed below the'sheets engagingrun of the belts 69.

Turning now to FIGURES 5 and 6, there is seen a structure for positioning thebelts 60 relative towickets 16 and for sensing jamming of the conveying structure to terminate printer and dryer operation. Abushing 94 is mounted on theshaft 68. Thebushing 94 may be secured to theshaft 68 in a variety of positions by means of aset screw 96 threaded within thebushing 94 and arranged to firmly engage theshaft 68. Rigidly secured to gle throw, normallyopen switch 102, the latter being mounted on thebase 26 and being maintained in a closed position by theactuator 98. Adjacent theswitch operator 100, there is placed an adjustable movement limiting mechanism comprising a nut 104 secured to thebase 26 and in which is received a threadedscrew 106. Thescrew 106 is arranged in the path of theswitch actuator 98 and, as seen in FIG. 6, is arranged to limit the counterclockwise movement of theswitch actuator 98. As an ultimate result of this construction, the counterclockwise movement of theshaft 32 is also limited. However, when theshaft 32 is rotated in a clockwise direction, it will be obvious that theswitch actuator 98, which is arranged to close switch 182 during contact with theoperator 100 thereof, will be'rotated away from thescrew 106 and the operator 1100 thereby permitting theswitch 102 to open. Thescrew 106 also serves as an adjustment for regulating the extent of such movement required to cause theswitch 102 to open by adjustably limiting the extent of depression of theswitch operator 100 by theactuator 98. As will be seen hereinafter, the switch arrangement just described is used to terminate the operation of a printer and the dryer drive in the event that a sheet sticks to a wicket or a component of the sheet handler and stripper.

Referring to FIG. 5, asecond bushing 108 surrounds theshaft 68 and may be secured thereto in a variety of positions by aset screw 110 threaded therein and adapted to firmly engage theshaft 68. Thebushing 108 is also provided with anaperture 112 in a side thereof which receives oneend 114 of aspiral spring 116 coiled about theshaft 68. Theother end 118 of thespring 116 is secured to thebase 26 by a screw 120. Thespring 116 is arranged to rotatably bias thebushing 108 and thus theshafts 68 and 32 in counterclockwise direction in reference to FIG-URES 2 and 6 such that theswitch actuator 98 is biased against thelimit screw 106. The construction just described permits adjustment of the angular relationship between thetubes 42 and the base 26 by varying the angular position of theswitch actuator 98 on the shaft 63 and also permits adjustment of the degree of bias applied to thetubes 42 toward the position just mentioned by vary ing the position of thebushing 108 with respect to theshaft 68. Additionally, as mentioned above, the construction permits the varying of the tube movement sensitivity of the switch 162 by varying'the position of thescrew 106.

Accordingly, thetubes 42 may be placed such that the run of thebelt 60 that is in substantially full contact with thefiat surface 46, will be approximately parallel to thewickets 16 as they pass thereby.

Turning now to FIG. 7, there is seen a form of a control circuit that may be used in practicing the invention. A pair oflines 122 and 124 are adapted to be connected to a source of power. Thevacuum pump motor 66 and thedrive motor 88 are connected across thelines 122 and 124 in parallel and are serially arranged with an off-onswitch 126 in theline 122. Additionally, in parallel with themotor 66 and 88 and in series with theswitch 126, a sensor and time delay control '128 is connected across thelines 122 and 124. Thesensor 92 is connected to the sensor andtime delay control 128. Thecontrol 128 also includes aswitch 130 that is initially closed by the response of thesensor 92 to a passingwicket 16 and which is maintained closed for a predetermined time thereafter. Conventional means as, for example, a motor which is initially energized by a pulse from thesensor 92 driving a cam surface and which is maintained energized during and deenergized after a predetermined period of revolution by another switch (not shown) in contact with the cam surface may be used to actuate theswitch 130. In series with theswitch 130, and across thelines 122 and 1-24, is a magneticclutch control 132 of conventional construction. The magnetic clutch 89 is connected to the magneticclutch control 132 and is arranged, upon energization of the magneticclutch control 132 through theswitch 130, to cause thebelts 60 to be driven.

The auxiliary dryer drive is indicated schematically at 134 and is connected across thelines 122 and 124. A printer and control therefor for sequentially printing sheets to be used in conjunction with thesheet dryer 12 is schematically indicated at 136. The printer 136 is connected directly to theline 124 and is connected to theline 122 through a pair of parallel circuits comprising acycle switch 138 and a printer cut-01f circuit 140. Thecycle switch 138 provides an alternative path for energization of the printer that is opened only when the printer has completed a cycle such that the latter cannot be stopped in mid-cycle. The printer cut-0E circuit 140 is in turn controlled by the double polesingle throw switch 102 through one pole thereof. The other pole of the double polesingle throw switch 102 controls a cut-ofl? circuit 142 for the dryer auxiliary drive 134. The cut-off circuits 140 and 142 may comprise relay switches in the power supplies for the printer 136 and the dryer auxiliary 134 that are maintained closed so long as theswitch 102 is closed. The dryer auxiliary drive 134 and the printer 136 additionally include separate manual off-on switches, not shown.

' The operation of the exemplary form of the invention described is as follows. The sheet stripper andhandler 10 is placed in an appropriate position relative to thesheet dryer 12, as for example the position shown adjacent the right-hand end of thesheet dryer 12 as shown in FIG. 1. The set screws 96 and in thebushings 94 and 108 respectively are loosened and theshaft 32 rotated within thebearings 30 and 31 such that the run of thebelt 60 substantially in contact withflat surface 46 of thetubes 42 is approximately parallel to awicket 16 from which a sheet is to be removed. Additionally, since the sheet dryer conveyor includes a plurality of side-byside wickets 16, such as shown in FIG. 3, thebase 26 is positioned such as to locate thebelts 60 in between thewickets 16. With thetubes 42 disposed in the proper angular relationship to thewicket 16, the bushing 94 (see FIG. 6) is rotated in a counterclockwise direction until theactuator arm 98 contacts thelimit screw 106,

thus closing theswitch 102. Theset screw 96 is then tightened. Thebushing 108 is then rotated in a clockwise direction against the bias of thespring 116 at least until there is suflicient bias exerted thereagainst to maintain thetubes 42 in the desired angular relationship with thewicket 16. If it is desired that thetubes 42 be subjected to a greater bias such that a greater force exerted thereagainst is required to cause them to deviate from the preselected position, thebushing 108 may be further rotated in a clockwise direction. When the desirable bias is achieved, theset screw 110 is tightened to cause the bias of thespring 116 to be exerted against theshafts 68 and 32 and thetubes 42.

At this point, the operation of the printer 136 may be initiated and thedryer 12 actuated, the conveyor being driven by the printer drive or the auxiliary drive 134. Theswitch 126 is then closed to energize thevacuum pump motor 66, thedrive motor 88 and the sensor and clutch control circuitry. Printed sheets to be dried are conveyed from the printer 136 to thesheet dryer 12 and are loaded on the conveyor thereof to be passed through thesheet dryer 12 to be dried. As a result, eachwicket 16 will support a sheet. The sheets are conveyed by thewicket 16 to thedryer enclosure 14 and eventually to the sheet handler andstripper 10.

Referring specifically to FIG. 2, awicket 16 bearing a sheet will be moved downwardly toward thebelts 60. At some point in such movement, the sheet will engage thebelts 60 and be drawn thereagainst by the low pressure adjacent each aperture 62 in thebelts 60. At this point, thebelts 60 are stationary. Further movement of thewicket 16 results in the wicket '16 falling away" from thebelts 60 such that thetransverse end portion 17 of eachwicket 16 is moved below the plane of thebelts 60 and out of the path of the sheets during stripping 7 movement. Still further movement of thewicket 16 causes it to be positioned adjacent thesensor 92 which responds thereto toenergize the time delay mechanism and close theswitch 130 fora predetermined amount of-time. The closing of theswitch 130 causes the magneticclutch control 132 to be energized to actuate the magnetic clutch 89 and cause the sheave 71 to be driven to move thebelts 60. Thebelts 60 then move the sheet out of the path of thefollowing wicket 16 with the sheet held thereon by the pressure differential created by the aperture 62 communicating with the vacuum pump 64. By virtue of the placement of thesensor 92 in relation to the sheet contacting run of thebelts 60, thetransverse end portion 17 of eachwicket 16 is below the surface of the sheet contacting run of thebelts 60 before movement of thebelts 60 is initiated and therefore will not obstruct movement of the sheets by thebelts 6! The period during which theswitch 130 is closed is preselected such that movement of thebelts 60 will be terminated prior to the contact thereof by a sheet carried on the following wicket If for some reason, a sheet on awicket 16 jams against thebelts 60 or their associated structure, it will be appreciated, that further movement of the wicket will cause thefollowing wicket 16 to engage the sheet to cause thebelts 60 and thearms 42 to be rotated clockwise about the pivotal support provided by the bearings and731. Should a sheet stick to a wicket-16, further movement of the sheet by the fouled wicket will cause similar movement of thearms 42. In the event thedrive 88 or the clutch 89 and associated circuitry of the sheet handler and stripper fail to initiate movement of thebelts 60, the-followingwicket 16 will engage the sheet to rotate thearms 42. Such a rotation will cause theshafts 32 and 68 to be rotated clockwise to lift theswitch actuator 98 off of thelimit screw 106 and the operator 1&0 ofswitch 102 to permit the latter to open. The opening of theswitch 102, as noted previously, will immediately terminate operation of the dryer auxiliary drive 134 if used or will terminate operation of the printer upon completion.

of the printing cycle in which it is engaged when the alternative path provided by thecycle switch 138 is additionally opened, and thus stop the dryer conveyor when the latter is being driven by the printer 136.

Having described a specific embodiment of my invention as required byUSC 112, I do not wish to be limited to the exemplary construction set forth, but rather,

to have my invention construed according to the true conveyor comprising intermittently operable stripper conveying means having a flat elongated conveying surface for engaging dried sheets carried by said wickets along substantially the entirelength of the sheets to support the same along their length and for conveying dried sheets away from said wickets and means responsive to the presence of a wicket at a point adjacent said conveying means for actuating" said conveying means after said hook-like end has passed said conveying surface for a predetermined time period sufiicient to remove a dried sheet from said wicket conveyor and less than the period of timerrequired for said movable wicket conveyor to carry the next subsequent wicket to said point adjacent said conveying means.

The combination of claim 1 wherein said flat elongated conveying surface comprises a run of an endless conveying structure, said endless conveying structure ineluding means for permitting fluid communication through said run and a vacuum manifold substantially in v contact with said run and communicating with said fluid communication means whereby dried sheets on said end- 1 less conveying structure are subjected to a vacuum to prising: first conveying means mounting a plurality of wickets, each of said wickets having a hook-like end portion and an elongated portion adapted to support a printed sheet for movement through a sheet treatment zone; second conveying 'means including at least two spaced belts disposed adjacent'said first conveying means each having an elongated sheet engaging, conveying run and arranged so that each of'said wickets may pass through a position between said belts with said elongated portion approximately parallel to" said runs; means for driving said belts; and means for sensing the presence of a Wicket at approximately said position for energizing said drive means for a time period less than the'tirne' period required for said first conveying means to move a subsequent wicket to said position, 7 i

4. The combination of. claim 3 wherein said belts are fluid pervious, said combination further including a vacuum manifold associated with said run of each of said belts having an opening disposed adjacent said run.

5. The stripping means of claim 3 including a portable.

tween said .second conveying means and said driving; means, and means responsive t said sensing means for' engaging said clutch for said predetermined time period,

each of said driving means, clutch and clutch engaging means being mounted on said portable base.

7. A sheet handler and stripper for use with a sheet dryer of the wicket type comprising: I

(a) a base,

(b) a shaft mounted on said base,

(c) a plurality of tubes secured to said shaft and adapted to have their interiors in fluid conimunica tion with a vacuum source,

(d) each said tubes including an opening extending therethrough into the interior of said tubes,

(e) a first sheave disposed at one end of each of said tubes,

(f) a second sheave disposed at the other end of each of said tubes,

g) a plurality of perforated belts each trained about one of said first and second sheaves and having'a run thereof substantially in contact with one of said tubes,

(h) drive means for selectively driving each of said belts; and

(i) wicket sensing means for a predetermined time after a wicket passes said belt.

-8. A sheet handler and stripper for use with a sheet adapted to have their interiors in fluid communicae.

tion with a vacuum source, (d) each said tubes including an elongated slot extending therethrough into the. interior of said tubes,

.(e) a first sheave disposed at one end of each of'saidtubes, (f) a second sheave disposed at the of said tubes, (g) a perforated belt trained about said first and second means for operating said drive other-end of each a sheet dryer of the wicket type comprising:

(a) a base,

(b) means mounting said base for selective movement thereof,

(c) a shaft pivotally mounted on said base and having a hollow center adapted to communicate with a vacuum source,

(d) a plurality of tubes secured to said shaft and having their interiors in fluid communication with said hollow center,

(e) each said tubes including a flat surface extending substantially the length thereof, said flat surface including an elongated slot extending therethrough into the interior of said tubes,

(f) a first sheave disposed at one end of each of said tubes,

(g) a second sheave disposed at the other end of each of said tubes,

(h) a perforated belt trained about said first and second sheaves and having a run thereof substantially in contact with said flat surface,

(i) motor means (j) drive means including a selectively operable clutch interconnecting said motor means and one of said sheaves for selectively driving said belt,

(k) wicket sensing means for operating said clutch to drive said belt for a predetermined time after a wicket pases said belt,

(1) means for adjustably and yieldably biasing said shaft in a plurality of positions relative to said base, and

(m) means responsive to rotation of said shaft from the position in which it is biased for deenergizing a sheet dryer of the wicket type.

10. A sheet handler and stripper for use with a sheet dryer having a sheet holder comprising:

=(a) a base, (to) a shaft movably mounted on said base,

(c) a tube means secured to said shaft and adapted to have the interior thereof in fluid communication with a vacuum source,

(d) said tube means including an opening connecting the exterior thereof with the interior thereof,

(e) a perforated belt having a run thereof substantially in contact with the opening of said tube means,

(f) drive means for selectively driving said belt; and

(g) sensing means for operating said drive means for a predetermined time after a sheet holder passes said belt.

11. A sheet handler comprising:

(a) a base;

(b) wheel means supporting said base whereby said base may be moved from location to location as desired;

(0) tube means mounted on said base and adapted to have their interior in fluid communication with a vacuum source, said tube means including an elongated opening having edges and connecting the ex terior thereof with the interior thereof;

(d) fluid pervious belts mounted for movement along said tube with a run thereof in contact with the edges of said opening;

(e) drive means for selectively driving said belt, said drive means being mounted on said base and movable therewith; and

(f) sensing means mounted on said base for sensing the presence of a sheet holder and for operating said drive means for a predetermined time period after a sheet holder is located at a point adjacent said belt.

12. Sheet handling means for use with a sheet heat treatment unit of the wicket type having a movable wicket conveyor mounting a plurality of wickets adapted to carry sheets to be treated through a heat transfer chamber, said sheet handling means comprising: intermittently operable conveying means including a movable surface for engaging said sheets and for conveying said sheets to a desired location relative to said wicket conveyor, means responsive to the presence of a wicket at a point adjacent said conveying means for actuating said conveying means for a predetermined time period sufficient to move a sheet to a desired position relative to the wicket and less than the period of time required for the wicker conveyor to carry the next subsequent wicket to said point adjacent said conveying means, and means for producing a vacuum only at said surface for holding sheets thereagainst.

13. The handling means ofclaim 12 wherein said movable surface comprises a run of an endless belt and wherein said vacuum means comprise means in said belt for permitting the passage of fluid through said belt and a vacuum manifold in continuous communication with said last named means.

References Cited UNITED STATES PATENTS 926,302 6/1909 Swahn 19 8-20 2,167,676 8/ 1939 Pechy 198-102 2,593,415 4/1952 Cummings 198-20 2,648,420 8/1953 Best et al. 198-l34 XR 2,772,880 12/1956 Garrett. 3,029,927 4/1962 Farwell 198-134 3,051,296 8/1962 Mertz 198- 134 3,147,971 9/1964 Key 271-69 XR EVON C. BLUNK, Primary Examiner. R. J. HICKEY, Assistant Examiner.

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