US3460472A

US3460472A - Transfer sheet clamping mechanism for a reproduction machine

Info

Publication number: US3460472A
Application number: US491561A
Authority: US
Inventors: Harold E Trumbull; James J Grimm
Original assignee: Xerox Corp
Current assignee: Xerox Corp
Priority date: 1965-09-30
Filing date: 1965-09-30
Publication date: 1969-08-12
Anticipated expiration: 1986-08-12

Description

Aug. 12, 1969 TRUMBULL ET AL 3,460,472

TRANSFER swam CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30, 1965 15 Sheets-Sheet 1 INVENTORS. HAROLD E. TRUM BULL JAMES J. GRIM k' f m #OR/VEI rs Aug. 12, 1969 H. E. TRUMBULL. ET AL TRANSFER SHEET CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30, 1965 15 Sheets-Sheet 2 INVENTORS. HAROLD E. TRUMBULL JAMES J. GRIMM BY Aug. 12, 1969 H. E. TRUMBULL E AL ,460, 7

TRANSFER SHEET CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30, 1965 15 Sheets-Sheet 3 INVENTORS. HAROLD E. TRUMBULL BY JAMES J. GRIMM ATTORNEYS TRANSFER SHEET CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30, 1965 1969 H. E. TRUMBULL ET AL 15 Sheets-Sheet 5 FIG. /6

INVENTORS. HAROLD E. TRU MIBULL Aug. 12, 1969 H. z. TRUMBULL E A 3,460, 7

TRANSFER SHEET CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30, 1965 15 Shees-$heet 6 SO L-l N m o 34 g INVENTORS. HAROLD E. TRUMBULL Aug. 12, 1969 T L ET AL 3,460,472

TRANSFER SHEET CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30. 1965 15 Sheets-Sheet INVENTORS. HAROLD E. TRUM BULL B JAMES J. GRIMM Q Q mwt TRANSFER SHEET CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30, 1965 Aug. 12, 1969 H. E. TRUMBULL E 15 Sheets-Sheet 8 TRUMBULL yMEs J. GRIMMI Aug. 12, 1969 H. E. TRUMBULL ET AL 3,46

TRANSFER SHEET CLAMPINCI MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30. 1965 15 Sheets-Sheet 9 m at .II

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INVENTORS. HAROLD E. TRUMBULL AMES J. GRlMlM BY Aug. 12, 1969 E. TRUMBULL ET Al. 3,460,472

TRANSFER SHEET CLAMYING MECHANISM FOR A'REPRODUCTION MACHINE Filed Sept. 50 1965 1s Sheets-Sheet 10 INVENTORS. HAROLD E. TRU MBULL BY JAMES J. GRIMM /& C

Aug. 12, 1969 H. E. TRUMBULL ET A 3, 6

TRANSFER SHEET CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30, 1965 15 Sheets-Sheet 11 mvxsmoizs. HARO E. TRUMBULL BY JAME GRIMM ATTORNEYS Aug. 12, 1969 H. E. TRUMBULL ET AL 3,460,472

TRANSFER SHEET CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30, 1965 l5 Sheets-Sheet 12 INVENTORS. HAROLD E. TRUMBULL JAMES J. GRIMM R y /X2.

Aug. 12, 1969 H. E. TRUMBULL ET AL 3,460,472

TRANSFER SHEET CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30, 1965 15 Sheets-Sheet 15 JNVENTORS. HAROL TRUMBULL JAMES GRIMM Aug. 12, 1969 H. E. TRUMBULL ET L ,460, 7

TRANSFER SHEET CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30, 1965 15 Sheets-Sheet 14.

c4 MOT-l SOL-l (g LMP-l 120v. g sow l l LS o INVENTORS. HAROLD E.TR BULL 2L5 BY AMES J. GR!

he. 26 Aozm 2, 1969 H. E. TRUMBULL ET AL 3,460,472

TRANSFER SHEET CLAMPING MECHANISM FOR A REPRODUCTION MACHINE Filed Sept. 30, 1965 15 Sheets-Sheet 15 INVENTORS. HA ROLD E. TRUM BULL BY AMES J. GRIMM United States Patent US. Cl. 101-432 1 Claim ABSTRACT OF THE DISCLOSURE A pressure-transfer reproduction machine for transferring ink from one sheet to another having rotatable drum and a pressure roller for exerting pressure between the drum and the roller. The machine has paper gripping devices for holding a transfer sheet upon the drum and includes an ejecting portion thereon for assisting in the removal of the transfer sheet from the machine.

The present invention relates to reproduction machines and more particularly to a gripping device for holding a transfer sheet to the drum of a machine which reproduces copies by mechanical pressure.

Generally, reproduction machines of the pressure transfer configuration which are particularly suited as an environment for the present invention are two broad types. One type, known as a spirit duplicator, requires a copying fluid or spirit which moistens each copy sheet as it passes between a rotatable platen which supports a master or transfer sheet and a pressure roller. The spirit dissolves some of the dye on the master sheet, and the resultant dis solved dyestutf is transferred to the copy sheet as it is transported between the rollers.

Another type of pressure transfer duplicating equip ment combines the effect of heat and pressure to effect transfer from a transfer sheet to a copy sheet. This type of equipment may take various forms and materials such as the use of fixing compositions for the dyes imprinted upon a master sheet wherein heat is utilized to cause or enhance reaction between the dye and the fixing composition. Special circuits and temperature control devices are provided in these duplicating machines for insuring optimum transfer conditions.

Significantly, the present invention takes on added importance in that it may be devised in a reproduction machine having compact size, requiring a minimum of operative steps, involving a completely dry process and which may be quickly brought into operation by the mere push of a button. With these advantages the machine, incorporating the invention, is particularly useful as a companion machine to the conventional typewriter, to be made a part of or an adjacent neighbor thereto and serve to eliminate the need to make carbon copies by use of the typewriter. In fact, the machine, incorporating the present invention, derives its most useful benefit in that reproduction of a typed original document may be accomplished solely by the machine, thus eliminating the cumbersome application of carbon paper to the typewriter and the burdensome manipulation of the carbon sheets in order to efiect erasures of the carbon sheets and correction to the original.

It is a principal object of the present invention to improve office reproducing machines incorporating a gripping device for clamping a transfer sheet to the drum of the machine, the machine being capable of making copies quickly, economically and accurately.

Another object of the invention is to allow positive closing of the gripping device for securely clamping the trans- 3,460,472 Patented Aug. 12, 1969 fer sheet to the drum of the machine and to allow selective opening of the gripping device for insertion of and removal of the transfer sheet.

Still another object of the invention is to assist in positive positioning of the transfer sheet for removal from the machine and to insure proper engagement of the strippers for such action.

In order to accomplish these and other objects of the invention, there is provided a sheet gripping or clamping mechanism in a reproducing machine which operates under a dry process requiring merely the application of pressure in order to effect transfer of information on an original document to ordinary copy paper. Any other suitable reproduction machine may be utilized with the present invention. The reproducing machine that will be described in association with the present invention comprises a rotatable drum for supporting therearound a transfer sheet and moving therewith an original document and then a sheet of copy paper. A roller is also pro vided and is arranged to be in pressure contact with the drum by means of a force producing mechanism for effecting ink transfer. Each revolution of the drum is adapted to complete one reproduction of the original document. There are included in the machine means for driving the drum, guide means and registering means for insuring accurate feeding and movement of the various sheets into and through the machine, under control of the programmer device, for controlling the movement or release of the sheets. The clamping devices are pivotally mounted for actuation relative to the periphery of the drum for positively clamping the transfer sheet thereto and includes means for positively positioning the transfer sheet for removal from the machine.

Further objects and advantages will become apparent after reading the following description when taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a right hand perspective view of the reproducin g machine which embodies the present invention;

FIG. 2 is a right hand perspective view of the reproduction machine with the covers removed, and a counter added;

FIG. 3 is a top view of the machine;

FIG. 4 is a sectional view of the machine taken along line 44 in FIG. 3;

FIG. 5 is a schematic view of the drum and pressure roller in peripheral contact to emphasize the crowned configuration to the roller;

FIG. 6 is a right hand end view of the machine with parts broken away;

FIG. 7 is a sectional view of the machine taken along the line 77 in FIG. 3 with parts broken away;

FIG. 8 is a sectional view of the machine taken along the line 88 in FIG. 3 with parts broken away;

FIG. 9 is a sectional view of the machine taken along line 9-9 in FIG. 3 with parts broken away;

FIGURE 10 is a left-hand view of the machine with parts broken away;

FIGURE 11 is a front view of the drum with parts broken away;

FIGURE 12 is a sectional view taken along line 12-12 in FIGURE 11 with parts broken away;

FIGURE 13 is a sectional view of the drum taken along line 13-13 in FIGURE 11 with parts broken away;

FIGURE 14 is a top view of the transfer sheet grippers;

FIGURE 15 is a side view of FIGURE 14;

FIGURE 16 is a schematic illustration of the relationship of the transfer material, an original, and the structure used in cooperation therewith;

FIGURES 17, 18, 19, and 20 are enlarged fragmentary views of the inventions various positions of operation;

FIGURES 21, 22, 23, and 24 are schematic views of portions of the programmer mechanism shown in various positions of operation;

FIGURE 25 is a schematic view of a portion of the drive mechanism in one position of operation; and

FIGURE 26 is a schematic electrical wiring diagram of the disclosed reproduction machine.

The reproducing machine to be described herein is particularly adapted for printing out copies on ordinary copy paper by means of a pressure transfer process involving a master or transfer sheet material produced as the first operative step in the use of the reproduction ma chine or of any particular run of the machine. The master or transfer sheet, in turn, derives or acquires the information to be reproduced from an original produced independently of the reproducing machine, such for example, by typing with a conventional typewriter.

In order to devise a transfer sheet that is usable with the present machine, the ink or pigment presented upon the transfer sheet must be transferable by the application of relatively high pressure. Production of the transfer sheet may be accomplished by two methods:

(a) The direct method wherein the transfer sheet is typed along with the original and a sheet of special carbon paper is positioned behind the transfer sheet with the carbon ink facing the master, and

(b) The indirect method wherein the informational image is formed by typing with a special typing ribbon onto the original from which the image is transferred to a transfer sheet under pressure. The present reproduction machine is adapted to accommodate a transfer sheet produced by either method; however, it is preferred that the indirect method be employed since this method would not involve the added manipulative steps with a typewriter, that is, arranging an original, a carbon sheet and transfer sheet material in a typewriter and insuring adequate alignment of these sheets relative to one another. Essentially, the indirect method involves single-sheet typing.

In the indirect method, the master sheet is generally made of wax paper which may be wax coated base stock paper, whereas in the direct method, the transfer sheet need not be wax coated. The ink formulation for either the ribbon in the indirect method or the carbon paper in the direct may include a small percentage of wax; a large percentage of pigment, usually iron oxide or carbon pigment; and a modifier, such as petroleum and chlorinated rubber, which serves as a binder.

In producing a transfer sheet by the indirect method, the ink from the typewriter ribbon is transferred to the original sheet by the striking of each typewriter key, as is the case with single-copy typing. The typed original is usable as such and may be mailed or routinely handled as an ordinary type ribbon copy. Reproductions of the original can be made by means of the present invention in view of the fact that a portion of the ink on the original will be transferred to the transfer sheet material by the application of pressure. To reproduce copies, the original sheet and a transfer sheet are aligned in the paper tray with the typed copy in contact with the coated surface of the tarnsfer sheet and fed into the machine incorporating the present invention wherein high pressure is applied as the sheets are rolled through the pressure area in the machine. This action transfers the ink from the original to the transfer sheet. The transfer sheet is retained in the machine while the original is fed out. To make copies, a sheet of ordinary copy paper is placed in the feed tray where it is automatically registered with the copy on the transfer sheet and then rolled through the pressure area of the machine. With the application of pressure, some of the ink is transferred from the transfer sheet to the copy sheet. This step may be repeated in order to produce any number of copy sheets, for example,

ten copies or more, depending upon the ink depth and the porosity of the papers utilized.

Throughout this description, the front of the reproducing machine, see FIG. 1, is regarded as that portion which the operator faces while placing sheet material on the machine for the reproduction. The right and left ends of the machine are regarded as being to the right and left of the operator as he faces the machine.

Referring to FIG. 1, the reproducing machine 2 embodying the present invention is shown. The reproducing machine 2 includes a front cover 4 and back cover 6. An input paper guide tray 7 is located in the top portion of the front cover 4 for inserting the transfer sheet and original or copy sheet. An indicator light 8 is mounted adjacent the input paper tray to indicate that the machine is ready for operation. A thumb Wheel 10 and number indicator Wheel 12 are mounted on the right hand side of the machine for dialing the number of copies desired. A push button 14 for commencing operation of the machine is located adjacent the number wheel. A paper exit guide 16 is located in the lower front portion of the machine.

In FIG. 2 the reproducing machine is shown with the covers removed. The machine includes a base 18 having mounted thereon a pair of side brackets 20 one on each side of the machine. A drum 22 shown in FIG. 11 includes a pair of end plates 24 each having a stud shaft 26 secured thereto. The drum 22 is mounted for rotation by the shafts 26 in the side brackets 20. Pivotally attached to each of the side brackets 20 is a side roll supports 28, between which is mounted a pressure roller 30. The pressure roller 30 is preferably a solid piece of metal and has stub shafts 32 thereon for mounting in the side roll supports 28. Each of the side roll supports 28 is pivotally mounted on the side brackets 20 about a shaft 34 secured thereto. The side roll supports 28 and the side brackets 20 are connected by means of a bolt 38 which is screwed into the upper portion 36 of each side roll support 28. The bolts 38 are mounted through the upper portion 40 of the side brackets 20., A spring 42 is mounted between the head of each 38 and an upper portion 40 of the side brackets 20, thereby forcing the side roll supports 28 and therefore the pressure roller 30 into lineal pressure contact with the drum 22.

The springs 42 are of relatively high strength in order to produce extremely high pressure contact between the pressure roller and the drum, in order to produce linear pressure on the order of between to 300 pounds per inch along the line of contact thereof.

The pressure roller 30 is mounted with the axis thereof substantially parallel to the axis of the drum, such that the roller 30 maintains peripheral contact with the drum 22. As will be presently described, the pressure roller is crowned or formed such that the peripheral diameter is larger at the center area, and tapering slightly toward the ends.

In FIG. 5, the crown configuration of the pressure roller 30 is shown schematically in relation to the drum. The tapered diameter from the center area, which is relatively flat toward the ends of the roller, as shown, are exaggerated in order to facilitate description. Good results have been attained from a configuration wherein each tapered end of the roller is approximately one-third of the length of the roller as is the center area, and the difference in diameter between the ends and the center area is on the order of one or two thousandths of an inch for a two and three-quarter inch diameter roller.

In operation of the machine during transfer there is a sheet of paper and a transfer sheet between the roller and the drum. An extremely high linear pressure or force exists along the linear contact of the roller and the drum with the paper and the transfer sheet therebetween as transmitted by the drum and pressure roller support shafts. Because the paper and transfer sheet are compressible and also because the supporting shafts are beyond the edge of the paper and the transfer sheet, the roller will be deflected; and if the pressure roller were of straight configuration, instead of crown, the pressure at the ends of the linear contact would be greater than at the center. The effect of this condition would be the production of copies that were darker at the edge portions of the copy sheet and lighter in the middle area. In addition, this uneven pressure axially along the drum produces a component of force which runs axially inwardly along the linear contact, and this component of force will result in the sheet being processed becoming wrinkled and creased out of shape.

With the provision of a crowned configuration to the pressure roller, the deflection of the roller caused by the extremely high pressure is balanced thereby resulting in parallel linear surfaces for the linear contact and even pressures throughout the contact. With the presence of an even pressure, the transferred image will be even in contrast or density. In addition, the balanced or even pressure will eliminate the axially directed component of force which would have produced wrinkling of the sheet.

The pressure roller 30 is driven by its frictional engagement with the drum 22. With this arrangement of the

support members

20, 28, relatively high pressures on the order of 175 to 300 pounds per linear inch may be achieved at the line of contact between the drum surface and the surface of the pressure roller.

From the foregoing it will be apparent that the linear force or pressure between the drum 22 and the pressure roller 30 is accomplished by the particular arrangement of the drum 22, roller 30, and the springs 42.

Means are provided for guiding sheets of material such as transfer of copy sheets and originals into, through and out of the machine. Other means are also provided to establish a relationship between the sheets for effecting programmed handling as the various sheets are conveyed through the machine and include sheet registration devices and sheet clamping mechanisms. In guiding sheets of material into the machine, the paper tray 7 is arranged above the machine to direct a single sheet or double sheets to the vicinity of the nip of the drum pressure roller arrangement. The tray 7 is provided with flanges 46 at each edge thereof for assisting in the lateral positioning of the sheets as the same are fed to the nip. An insert paper guide device 48, shown in FIG. 4-, is mounted on the upper portions 36 of the side roller supports 28 for directing and assisting in the positioning of the sheets of paper. A shutter 50, described below, is also provided for assisting in the positioning of the sheet.

In emerging from the machine, the sheet of material is guided by the paper exit guide mechanism generally indicated as 16. The paper exit guide 16 is pivotally mounted on the shafts 32, which, as previously stated, support the pressure roller 30 for rotation upon the machine. This paper exit guide mechanism includes an upper stripper 52 and a lower stripper 54. As shown in FIG. 4, the upper stripper 52 is slidably mounted in the paper exit guide 16 and adjustable relative thereto. The paper stripper 52 has slots 53 which ride along bolts 55 mounted on guide 16. The bolts 55 in slots 53 are provided to permit adjustment between the upper stripper 52 and the lower stripper 54 which is rigidly secured to the guide 16. The upper stripper is formed with a longitudinal edge adjacent the pressure roller 30 while lower stripper has a longitudinal edge 54' adjacent the drum 22. The longitudinal edges of

strippers

52, 54 are preferably knife edged in their outer extremities. As a sheet or sheets of material are forced out by the rotation of the drum and the pressure roller the sheet or sheets are prevented from adhering to the roller 30 and are stripped off this roller by the stripper 52 and guided out the paper exit guide. The lower stripper 54 is provided with slot 57 (see FIG. 16) to allow the transfer grippers and registration devices described below to pass therethrough without interferring with the stripper 54. The edge 54 of lower stripper 54 serves to strip the original and each copy sheet from the transfer sheet in a manner to be described below. The edge 54 of lower stripper 54 also strips both the transfer sheet and the last copy produced in the machine as described below.

The

strippers

52 and 54 on the paper exit guide 16 are maintained in operative relation with the pressure roller 30 and the drum 22 by a pair of paper exit guide locks 56 (see FIGS. 2 and 9). The paper exit guide locks 56 are pivotally mounted on end plates 58 of the paper guide exit guide 16 by means of pins 60 secured to plates 58. A slot 62 formed in each paper exit guide lock 56 engages a paper exit guide locking bracket 64 secured on the base 18 thereby maintaining the

strippers

52 and 54 in operative relation with the roller 30 and drum 22. A spring 66 secured at one end to each of the plates 58 and at the other end to the lock 56 maintains each guide lock 56 in engagement with each bracket 64 and against stops 68 mounted on the plates 58. The upper portion 70 of each guide lock is easily accessible from the front of the machine when the front covers are removed for permitting manipulation by the operator of the locks 56. The locks 56 are adapted for rotation counterclockwise as viewed in FIG. 9 for unlocking the paper exit guide 16, that is removing of the brackets 64 from the slots 62, for allowing clockwise rotation of the end plates 58 and consequently the paper guide 16. In this manner should a paper jam occur at this point, the paper guide may be removed to reposition the

strippers

52 and 54 and permit clearing of jammed material.

A first support bracket 72 is mounted on the base 11 at the rear thereof and a second support bracket 74 is mounted on the left hand side bracket 20 (see FIG. 3). A motor MOT1, for driving the drum 22, is supported thereabove by a support clamp 78 secured on the first support bracket 72 and by the second support bracket 74 secured on the bracket 20. The motor MOT-1 is provided with a gear reduction mechanism 80 mounted between the motor and the support bracket 74. The motor drives the drum 22 through a suitable chain 82 mounted between a drive gear 83 secured to the shaft of the motor and a sprocket 84 mounted on the left plate 24 of the drum.

The motor MOT-1 is provided with means for controlling rotation of its shaft and to serve as a brake for this rotation. This means includes a solenoid SOL-1 mounted on the upper portion 40 of the right hand support bracket 20 by a support member 38 and a braking device operable upon the motor when the solenoid is deenergized. The braking mechanism includes motor clamp mounted to the right hand side of the motor casing 91 for slidably supporting a brake shoe 92 which cooperates with a brake disc 94 which is secured to the shaft of the motor to be rotated therewith. The solenoid SOL1 is connected to brake shoe 92 for moving the same into and out of braking engagement with the brake disc 94 by means of a linkage comprising a brake link 96 connected to the solenoid armature and the brake shoe 92. The link 96 projects through a suitable opening formed in the clamp 90 and is normally biased by a spring 98 held in compression between the clamp 90 and shoe 92 in order to maintain the shoe 92 in engagement with the disc 94 when the solenoid SOL-1 is tie-energized. The brake shoe 92 is actuatable when the solenoid SOL-1 is energized to become disengaged from the disc 94 to permit actuation of the motor drive and rotation of the drum, as will be discussed below.

The machine is provided with means for establishing positionable and operative relationships between a transfer sheet and an original or copy sheet which are introduced into the machine in order to effect programmed handling of the machine operation. These means include sheet registration devices and clamping devices as Well as various operative mechanisms associated therewith.

Before commencing the description and operation of these devices, a brief outline of the sheet manipulation that occurs during the complete machine cycle will now be made. During the first stage of operation of the machine both a blank transfer sheet and an original which has been typed or otherwise imprinted with appropriate ink formulation, which will readily transfer from one sheet to another by the application of extreme pressures, are inserted into the nip of the drum-pressure roller combination. It is imperative at thi step that the transfer sheet be applied so that it will be in contact with the drum 22 during rotation thereof. Both the transfer sheet and the original are driven through the nip of the drum-pressure roller and during the drive, which in this stage will be a single revolution of the drum, the transfer sheet will become clamped to the drum and remains so while the original is immediately stripped and directed out of the machine by means of the paper exit guide 16, Thus, the appropriate ink content on the original typed script or the image areas is transferred to the transfer sheet forming a mirror image of the image areas on the transfer sheet.

The next step in the cycle of operation requires the insertion into the machine of individual sheets of copy paper. During this stage the image on the transfer sheet is transferred to each copy sheet as they are inserted individually in the machine. During each transfer, the transfer sheet remains on the drum and the copy sheet is stripped out of the machine until the last programmed copy sheet has been made. As the last copy sheet is being stripped out, the transfer sheet is also being removed from the machine so that both sheets more or less are removed substantially simultaneously.

For automatically controlling positioning of the original sheet of material from which a transfer sheet will drive its inked image and for automatic positioning of subsequently applied sheets of copy paper, the drum 22 is provided with a plurality of registration devices 106 each having a registration pin 108 against which the leading edges of copy sheets or the original sheets abuts and which are arranged in a line parallel to the axis of the drum but coincident with the periphery thereof. As shown in FIG. 13, the registration pin 108 extends radially of the drum beyond the periphery thereof and is formed wrth a forward portion 110 which serves as a registration stop and against which the leading edge of an original or copy sheet is adapted to abut. The upper surface 111 aids in the removal or stripping of the original or copy sheet from the machine after a pressure transfer cycle. Th registration device 106 is adapted to slide within a cylindrical element 112 which is tightly fitted into the openings 114 formed in the wall of the drum 22. As shown in FIG. 16, there are five registration devices mounted 1n openings 114 in the drum 22. These registration devices are arranged in a line parallel to the axis of the drum s that the stops 110 will be adapted to engage the leading edge of the original or copy sheet.

Means are provided for slidably retracting each of the pins 108 within the cylindrical element 112 and thus each of the pins 108 is formed with a slot 116 through which a fixed retaining pin 118 projects for permitting limited radial movement of pin 108 relative to the drum. The pin 118 may be secured to the walls of the cylindrical element 112. A lift means in the form of a spring 120 normally held in compression within the element 112 between a ledge 122 formed therein and the inner surface of the stop 110 normaly biases the registration pin 108 outwardly and the stop 110 slightly beyond the periphery of the drum surface.

As shown in FIGS. 16, 17, and 18, the registration stops 110 are adapted to engage a sheet of material such as copy paper or an original P. The sheet P, when laid upon the paper tray 7, is guided by the chute 48 and when moved toward the nip of the drum-pressure roller combination is prevented from assuming any position except that shown in FIGS. 16 and 17. The illustrated position as shown in FIG. 17 is that assumed by the original P and the transfer sheet T just prior to initial operation of a reproducing cycle. The forward edge of the sheet P is shown in engagement with the registration stop which is held slightly inward of the drum against the bias of the spring by the pressure roller 30 in engagement with the uppermost points of the stops. The purpose of the registration stop 110 is to position the copy sheet or original P along the nip of the drum-pressure roller combination prior to commencement of the operation of the machine. As the registration stops 110 are moved through the nip of the drum-pressure roller combination, they are forced radially inwardly of the drum.

The drum 22 is also provided with a plurality of transfer sheet grippers generally indicated as 126 which serve to selectively clamp and support a transfer sheet, designated by the letter T, to be the drum periphery. These transfer sheet grippers 126 are spaced alternately with the registration device 106 and are arranged along a line parallel to these devices but spaced slightly forward therefrom. As shown in FIG. 16, the transfer sheet T is formed with a scalloped support edge having extensions 128 which are each applied to one of the grippers. Since there are four illustrated extensions 128 only four grippers are necessary. It is also shown in FIG. 16 that the grippers 126 and the registration devices 106 are arranged such that the scalloped edges 128 of the transfer sheet T leads, or is forward of the leading edge of the original or copy sheet P. The transfer sheet is provided with a wax coating W for the purpose described above for use in the indirect method of the pressure transfer process.

The details of one of the transfer sheet grippers are shown in FIGS. 14 and 15. Each gripper includes a cylindrical insert 132 mounted in a suitable circular opening 134 formed in the wall of the drum 22 and is formed with a plate portion 135 bent across the open end of the insert. Each of the transfer sheet grippers 126 includes a clamping device 136 rotatably mounted on a shaft 138 secured in the walls of cylindrical insert 132. The grippers support the transfer sheet between the clamping devices 136 and the surfaces 137 of the plate portions 135. A spring 140 is mounted on the shaft 138 and serves to normally rotate the device 136 to maintain the clamping device 136 in a closed position as shown in FIGS. 15 and 18. The gripping device 136 is formed with a portion 141 that rotates therewith about the shaft 138 for aiding in the ejection of the transfer sheet from the machine as described below.

Each clamping device is provided with an extension arm 142 which has a roller 144 mounted on the extreme end thereof. The roller 144 is adapted to ride on transfer lock pivot arms 146 as shown in FIGS. 11 and 12. The pivot arms 146 are mounted on a shaft 148 mounted within the drum 22 on and between the side plates 24 in parallelism with the axis of the drum. Rotation of shaft 148 and consequently the levers 146 is effected by a transfer lock shaft actuator 150 secured to the shaft externally of the drum at one end thereof (see FIG. 11). The actuator 150, in turn, is rotated by a programming mechanism to be described hereinafter which is operable upon a roler 152 which is mounted on the end of the actuator 15 As the roller 152 is contacted by the programming mechanism, the transfer lock shaft actuator 150 rotates the shaft 148 thereby pivoting the arms 146 in a clockwise direction as shown in FIG. 12. Each of the arms 146 contacts one of the rollers 144 mounted on the extension arm 142 of the clamping device 136 and rotates this arm in a counterclockwise direction about the shaft 138 against the biasing action of the spring 140. This, in turn, will rotate the device 136 about the shaft 138 for releasing the extensions 128 of the transfer sheet T. The clamping devices 136, which remain in a normally closed position, are opened twice during the opera ion of the last;

reproduction cycle. They are opened when the machine comes to and remains at rest as shown in FIG. 17 thereby in condition for accepting a transfer sheet prior to operation of the machine. The clamping devices are also opened during the last cycle of operation at which time the gripper is opened by the programming mechanism to positively position the transfer sheet to be stripped out of the machine along with the last copy sheet made.

The reproduction machine is provided with a programmer mechanism 160, as shown in FIG. 9, which controls the operation of the machine once it is set in motion and in cooperation with a copy counting mechanism, a copy indicating mechanism, and an electrical control circuit. The programmer mechanism 160 illustrated in operative detail in FIGS. 21-24, is located on the right-hand side of the machine and comprises a number of control levers which assume various motions and positions during a single and complete reproduction cycle. Such a reproduction cycle requires at least two complete rotations of the drum 22, one to produce a mirror image on the transfer sheet and one revolution to produce one copy from the transfer sheet. The structure of the programmer mechanism and the copy indicating mechanism is such that every produced copy desired requires one full rotation of the drum. For any series or multiple copy program, there will be as many drum rotations as there are programmed copies to be made plus one additional rotation to produce the transfer sheet.

The machine is shown in the normally off position in FIGS. 4, 6, 7, 8, 9, and The machine in this position is ready to be programmed for operation and ready for actuation of the programmer mechanism and the push button 14.

After the thumb wheel 10 has been set, as described below, the push button 14 is then ready for operation. The indicator light 8 is turned on as described below, indicating that the machine is ready to accept a transfer sheet and an original.

The push button 14 is provided with slots 162 therein which ride on fixed pins 164 as it is depressed. The push button 14 is normally held in the outward position as shown in FIG. 9 by a spring 166 mounted in one of the slots 162 between the pins 164 and an internal surface of the button. The pins 164 are mounted on a bracket 168 which also supports the button 14. The bracket 168 has a retaining element 170 that contacts a stepped portion 172 formed on the push button for positioning and retaining the same in the bracket 168.

The push button 14 is formed with a cam. surface 174 which is adapted to operate a shutter gripper release link 176 in the form of a bellcrank pivotally mounted upon a pivot 178 secured to the bracket 168. A roller 180, mounted on the adjacent end of the bellcrank 176, rides a cam surface 174 as the button is depressed until it contacts an inclined step portion 175 thereon for rocking the bellcrank about the pivot pin 178. The other end of the bellcrank 176 contacts one end of a gripper lock 182 also in the form of a bellcrank pivotally mounted about a pivot pin 184 secured to a bracket 186. The bracket 186 is secured by a flange 187 to the right-hand side bracket 20 (see FIG. 7) in order to maintain the pivot pin 184 for the gripper lock in a fixed position. The gripper lock 182 is biased by a spring 188 secured between the other end of the gripper lock bellcrank 182 and the bracket 186 in the counterclockwise direction as shown in FIG. 9 in order to maintain the other end of the lock 182 in engagement with the adjacent end of the link 176.

It will be understood that as the link 176 is rotated by the engagement of the roller 180 upon the step 175 will produce clockwise rotation of the bellcrank lock 182.

One edge of the gripper lock 182 normally engages a transfer cam lock link pin 190 mounted on a transfer cam lock link 192 by the biasing action of the spring 188. The transfer cam lock link 192 is pivotally mounted on a pivot pin 194 secured in a fixed position on the right-hand side roll support 28.

With the bellcrank 176 held in a fixed position by the engagement of the roller to the cam. surface 174, the bellcrank 182 is also fixed and thereby remains normally locked against the pin 190. Looking of the pin prevents movement of the link 192 in the clockwise rotation. Upon the release of the pin 190 by depression of the button 14, the link 192 is free to rotate in a clockwise direction.

The transfer cam lock link 192 serves a dual function: (1) to close the transfer grippers 126 and (2) to retract the shutter 50. In accomplishing this first function, the transfer cam lock link 192 is operatively associated with a transfer insert actuator lever 196 pivotally mounted on a pin 198 secured to the right-hand side support 20. The upper end of the lever 196 is formed with a cam edge 199 adapted for engagement with a roller 202 mounted on the extreme end of the lever 192. A spring 204 attached to the base 18 and the lever 196 maintains the cam edge 199 in contact with the roller 202 for all positions of the

elements

192 and 196. A spring 206 attached between the transfer cam lock link 192 and the transfer insert actuator lever 196 normally biases the link in a clockwise direction and accomplishes this without affecting the action of the spring 204 in keeping the cam edge 199 on the roller 202. The roller 202 on transfer cam lock link moves along the cam surface 199 of the transfer insert actuator lever 196 for imparting limited rocking movement of the latter. At the lower end of the lever 196, there is formed a cam surface 207 which is adapted to engage the roller 152 on the actuator 150.

As will be described below, during a stage of the reproduction cycle, the roller 152 will engage the surface 207 which limits movement of the roller to produce a slight rotation of the actuator 150 to open the clamping devices 126 to the position shown in FIG. 17.

In the event the link 192 is rotated clockwise the roller 202 will slide downwardly along the cam surface 199 for permitting counterclockwise rotation by the lever 196 by the spring 204 to remove the surface 207 from the path of movement of the roller 152 thereby permitting unrestricted closing of the clamping devices 126 by means of the springs 140.

During the second function of the lock link 192 in retracting the shutter 50, the lock link 192 releases a shutter actuator link 208 from its normally held position as shown in FIG. 9, wherein the shutter link 208 holds the shutter 50 in a releasably held position. In order to accomplish this action, the lock link 192 is pivotally connected by a pin 210 to one end of the shutter link 208 which is pivotally connected by a pin 211 at the other end to a paper guide shutter actuator 212 secured to the shutter 50 (see FIGS. 9 and 10). The shutter 50* is supported for rotation about the shaft 32 of roller 30 by the shutter actuator 212 one mounted on each end thereof.

As the pin 190 is released by the rocking of the gripper lever lock 182, the transfer cam lock link 192 will rotate in a clockwise direction thereby moving the shutter link 208 out of a releasably fixed position provided by its contact with a pin 213 mounted on the drum 22 as shown in FIG. 9. When the machine is not in operation, the pin 213 abuts the adjacent end of the link 208 to maintain the same and the actuator 212 in the position shown in FIG. 9 wherein the shutter 50 is in a closed position as shown in FIG. 17. While in a closed position, the shutter 50 serves as a paper guide along with the paper guide 48.

As the link 192 is rotated in a clockwise movement, it moves the link 208 out of interfering relation with the pin 213, wherein the link 208 is free to swing to the right from the position shown in FIG. 21 to the position shown in FIG. 22, as indicated by the arrow. This action is possible by the provision of the pivot pins 210, 211 and the