US3410204A - Line printer and coordinated line feed means - Google Patents

Description

Nov. 12, 1968 H. F. BURKHARD 3,410,204

LINE PRINTER AND COORDINATE!) LINE FEED MEANS Filed Oct. 21, 1966 2 Sheets-Sheet 1 FIG.|

INVENTOR,

HENRY F. BURKHARD Nov. 12, 1968 H. F. BURKHARD 3,410,294

LINE PRINTER AND COOHDINATED LINE FEED MEANS 2 Sheets-Sheet 2 ,II \\\nYEI I2 25 PRINTING 8-CONTROL 65 43 SIGNAL GENERATOR Filed 00 21, 1966 FIG. 2

SELECTOR LOGIC FIG. 4

INPUT D E E rr. E N L m L AM N R G E l N S E G INVENTOR, HENRY F. BURKHARD ATTORNEYS United States Patent 3,410,204 LINE PRINTER AND (ZOORDINATED LINE FEED MEANS Henry F. Burkhard, Eatontown, N.J., assignor to the United States of America as represented by the Secretary of the Army Filed Oct. 21, 1966, Ser. No. 588,639 3 Claims. (Cl. 101-93) ABSTRACT OF THE DISCLOSURE A printer is provided with print heads which are capable of printing on a print receiving medium during the line feed operation. A first group of print heads, at the beginning of the line, are moved from the normal printing location down one line width so that these print heads will be in position to start printing the next line. During the line feed operation, a sprocket mechanism will line feed both the medium and the first group of print heads in unison up to the normal printing location. As the medium and the heads are being fed, however, printing may take place since the heads and medium are at a zero relative velocity and the heads are properly aligned with the medium.

The present invention relates to high speed printers, and more particularly to an improved printer capable of printing at a high constant rate which is not interrupted during line feed operations.

Those concerned with the development of high rate telegraphs, computers, data processors, etc., have recognized the need for increasing substantially the speed of present day high speed printers. However, one of the problems confronting designers of high speed printers has been the elimination of the time delays introduced as a result of the line feed operation. Such time delays result in either the loss of some information or the necessity of providing a storage means for storing the information received during the line feed period. The present invention overcomes these ditliculties by providing a printing device which has means for printing during the line feed periods.

The exact nature of this invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification relating to the annexed drawing in which:

FIGURE 1 is a perspective view of the invention;

FIGURES 2 and 3 represent side views, partly in section, of the invention as shown in FIGURE 1; and

FIGURE 4 is a block diagram of the electronic controls for the invention of FIGURES 1-3.

Referring now to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, there is shown a printer contained in a housing 11 having anentrance slot 12 and anexit slot 13 for a sheet ofpaper 14 which is fed past theprinter 10 by afeed mechanism 15.

Feed mechanism 15 comprises adrive roller 16 havingsprockets 17 thereon, and anidler roller 18. Apaper feed tractor 19, which includes an endlessflexible belt 20 havingsprockets 21 andopenings 22 located at the edges thereof, extends aroundrollers 16 and 18.Sprockets 17 onroller 16 communicate withopenings 22 to drivetractor 19.Roller 16 is driven by a motor 70', FIGURE 4, attached to driveshaft 23. Idlerroller 18 is mounted onshaft 24 to freely rotate under the influence oftractor 19 which is in frictional contact therewith.

A sheet ofpaper 14 having perforations 26 at the edges thereof extends from the fanfold through slot Patented Nov. 12, 1968 12 to the interior of housing 11 where it passes overtractor 19 withsprockets 21 extending through slots 26. Thepaper 14 then passes throughslot 13 to the exterior of housing 11.

Theprinter 10 comprisesmoveable printing heads 30 andstationary printing heads 31 which are mounted on an axle in juxtaposition to thepaper 14.Heads 30 are free to rotate aboutaxle 32 and eachhead 30 has a depending printinghead lifter arm 33.Printing heads 30 and 31 may take any of the well known froms which print on either a mechanical, thermal, optical, or electrical principle. An example of a suitable thermal printing head may be found in US. Patent 3,161,457.

The dashed lines in FIGURE 1 extending fromheads 30 toheads 31 indicate that the heads, either moveable or stationary, located in these locations have been omitted to simplify the illustration.

A control mechanism for controlling the position ofmoveable printing heads 30 includes a series ofrelease magnets 40 and a litter bar 41 mounted on apedestal 42.Release magnets 40 comprise a U-shaped portion having acoil 43 wound thereon and a pivotedstud 44 connected to the U-shaped portion by aspring 45 which normally biases thestud 44 to a position just under arm 33 (see FIGURE 3). In this position the printing heads are held bystud 44 in the normal printing position and are aligned withstationary heads 31. However, upon energization ofmagnet 40,stud 44 is moved out from underarm 33 and the associatedhead 30 will rotate aboutaxle 32 untilarm 33 rests on bar 41, which is normally biased down uponpedestal 42 bysprings 46 to the position shown in FIGURE 3. Bar 41 is guided for free movement in the vertical direction by atriangular shaft 48 which is free to ride in vertical slots 47. The triangular shaft and the slot cooperate to permit rotation of bar 41 in the counterclockwise direction as seen in FIGURES 2 and 3. However, rotation in the clockwise direction by bar 41 is prevented past the position shown in FIGURES 2 and 3. Bar 41 also includes anose portion 49 which protrudes pastpedestal 42 into the path of movement ofsprockets 21. Sprockets 21 will lift bar 41 offpedestal 42 when thepaper 14 is being fed. When bar 41 has reached the uppermost position,coil 43 will be deenergized,stud 44 will be released and move to the position just underarm 33, and asolenoid 50 mounted on housing 11 will be energized to movearmature 51 into contact with bar 4 1 to rotate the bar 41, thereby strippingnose 49 offsprockets 21 and permittingsprings 46 to force bar 41 down ontopedestal 42.

The sequence of operations of the printer and the movements of the various controls may be best understood with references to FIGURES 2, 3, and 4. The input line would usually contain the printing information and the control instructions such as line feed. This information may be in coded form. Alogic circuit 61 will process the input signal and determine if it is a printing signal or a control signal. If the input signal is a printing signal, it will be fed togenerator 62 vialine 63 where theproper printing head 30 or 31 will be energized via one of the lines contained incable 64.Generator 62 will also generate a control signal to operatemagnets 40 by energizing one of thecoils 43 viacable 65 which passes through areset switching device 71. The printing heads are normally in the position shown in FIGURE 3 when the printing signal is transmitted to theheads 30 and 31 bygenerator 62. After ahead 30 performs its particular printing operation, thecorresponding coil 43 will be en ergized permitting the head to be released and fall to a position wherearm 33 rests on bar 41. Theheads 30 will remain in this position until a line feed operation is initated. A line feed operation will be initiated by eithergenerator 62 vialine 67 when thelast head 31 has been operated (end of line), or by an input signal vialine 66 when a Line Feed" signal has been received at theinput 60. Linefeed signal generator 68 will then energizemotor 70 vialine 69. Motor 70 will rotateroller 16 which will drivetractor 19 to lift both thepaper 14 and bar 41 viasprockets 21. Now, aspaper 14 is being fed,heads 30 will be moving up to the normal printing position as shown in FIGURE 3. However, since the printing heads and the paper are both moving in unison during this line feed operation, printing may continue during this period. Therefore, because printing is now possible during the line feed operation,generator 62 may continue to transmit printing information overline 64 without any loss of information or storage requirement. The number of moveable heads 30 which are employed will depend on the length of time required to complete the line feed operation and the rate at which information is being received overline 60.

After the line feed operation is completed, themotor 70 will generate a reset signal over line 7'2 to energize thereset switch 71, thereby deenergizing allcoils 43 and releasingstuds 44. A signal is also fed tosolenoid 50 when motor '70 has completed its rotation, thereby energizing thesolenoid 50 and moving armature 51 (see FIGURE 2) into contact with bar 41 to rotate the latter out of engagement withsprockets 21. It is again pointed out that during the line feed operation printing information may continue to be fed to the printing heads overcable 64 without any interruption.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings.

It is noted, for example, that the moveable printing heads 30 may be designed to move along a more complex path than the simple are shown in the drawing. It would, of course, be desirable to provide a motion for the moveable printing heads 30 which would eliminate any relative motion between the paper and the heads during the line feed operation. For example, in the disclosed embodiment a vertical translational motion ofheads 30 would produce less relative movement between theheads 30 and thepaper 14 during the line feed operation than would the simple rotational motion which is shown merely for purposes of illustration. Of course, in machines using other modes of printing even more complex movements of the printing elements and the feed mechanisms would be required. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A printer comprising; a plurality of print heads linearly disposed at a first printing station; a print receiving medium; energizable printing means operably associated with each said print head to cause said print heads to print selective characters on said medium; means responsive to the operation of each said printing means for moving a predetermined fixed group of said print heads to a second printing station upon energization of said printing means; feed means for intermittently feeding said medium and for moving simultaneously said print heads at said second station back to said first station while feeding said medium at substantially the same linear speed in the direction of feed of said medium; and said predetermined fixed group of print heads being in printing relationship with said medium during said movement.

2. A printer comprising; a plurality of printing means for printing in succession a plurality of selective characters in a line on a print receiving medium, feed means for feeding said medium in a step by step fashion past said printing means in a direction substantially perpendicular to said line to form a plurality of successive parallel lines of print on said medium; means associated with each said printing means of a group of said printing means located at the beginning of said line, for moving the associated printing means from the original printing position through a distance of one of said line widths in a direction opposite to the direction of feed for said medium; and means responsive to said feed means for moving the printing means of said group back to the said original printing position with substantially zero relative speed between said medium and said printing means in the direction of feed of said medium.

3. A printer comprising; a plurality of print heads, each said head having means for printing selective characters on a print receiving medium; said print heads mounted side by side along a first line, a feed tractor mounted adjacent said print heads for movement in a first direction perpendicular to the line of said print heads; means on said tractor for engaging a print receiving medium; input means for energizing said print heads in succession from one end to the other end of said line of said print heads; a first group of said print heads at said one end being moveable out of said first line to a second line parallel to said first line, means associated with each said print head of said first group for moving said associated print head from said first line to said second line upon energization of said print head by said input means; and drive means for moving said feed tractor and said print heads of said first group into said first line with substantially zero relative speed in said first direction.

References Cited UNITED STATES PATENTS 196,025 10/1877 Kurtzmann t 101-92 1,506,242 8/ 1924 Keller 10192 1,896,538 2/1933 Bryce t 101--93 2,915,966 12/1959 Jacoby 10193 2,915,967 12/1959 Gehring et al. 101-93 2,935,016 5/1960 Miller 101-93 3,128,694 4/1964 Kittler 10193 3,139,820 7/1964 Kittler 101--93 3,228,325 1/ 1966 Miller 10193 3,309,989 3/ 1967 Solheim et al. 101---93 WILLIAM B. PENN, Primary Examiner.

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