US2828689A - Sheet transporting mechanism for duplicating machines - Google Patents

Description

April 1 1958 2,828,689 SHEET TRANSPORTING MECHANISM FOR DUPLICATING MACHINES Filed April 17, 1956 w. RITZERFELD ETAL '7 Sheets-Sheet 1 InVemorS WiWel RVued M (1AA CDerMarA @(h erkl :slmwhmQ wlm April 1, 1958 w. RITZERFELD ET AL 2,828,689

SHEET TRANSPORTING MECHANISM FOR DUPLICATING MACHINES Filed April 17, 1956 7 Sheets-Sheet 2 Inventors:

April 1, 1958 w. RITZERFELD ET AL 2,828,689

SHEET TRANSPORTING MECHANISM FOR DUPLICATING MACHINES Filed April 17, 1956 '7 Sheets-Sheet I5 Inventor:- Wikalm QH'ZQYQH am April 1, 1958 w. RITZERFELD ET AL 2,828,689

SHEET TRANSPORTING MECHANISM FOR DUPLICATING MACHINES Filed April 17, 1956 -7 SheetsSheet 4 @emm Qww' 35= mum es em April 1, 1958 w; RXTZERFELD ET AL 2,828,589

SHEET TRANSPORTING MECHANISM FOR DUPLICATING MACHINES Filed April 17, 1956 7 Sheets-Sheet 5 I April '1, 1958 w. RITZERFELD ET AL 2,828,689

SHEET TRANSPORTING MECHANISM DUPLICATING MACHINES Filed April 17. 1956 7 Sheets-Sheet 6 lll April 1, 1958 w. RITZERFELD ET AL 2,828,689

SHEET TRANSPORTING MECHANISM FOR DUPLICATING MACHINES Filed April 17, 1956 7 Sheets-Sheet 7 &

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InVenf0r'5=- when Qwmrku M4 I Q k QH-RWQM &- MAMQ-QQA aszasss SHEET TRANfiWQRTiNG MECHANISM FOR BUPLKCATING MACHENES Wiihelm Ritzerfeld, Berlin-Dahlem, and Gerhard Ritzerfeld, lierlin firnnewald, Germany Appiication April 17, 1956, erial No. 578,784

(Jlaims priority, application Germany April 23, 1955 15 Claims. (Cl. 161-232) The present invention relates to a sheet transporting mechanism for duplicating machines and more particularly to a sheet transporting mechanism for a duplicating machine of the type in which lithographic printing forms are directly printed on a copy sheet.

it frequently happens in duplicating machines that copy sheets stick to the printing foil which is carried by the printing roller. This is particularly the case in duplicating machines which use a lithographic printing foil carrying a mirror script in a greasy ink.

i t is one object of the present invention to overcome this disadvantage, and to provide a sheet transporting mechanism for continuously transporting a copy sheet from a feeding station to a delivery station and through the printing line.

it is another object of the present invention to provide a sheet transporting mechanism which stops at a position in which copy sheets are inserted into the transporting mechanism.

it is another object of the present invention to provide a manual control of the sheet transporting mechanism in order to permit an irregular supply of copy sheets by a manual operation.

it is a further object of the present invention to provide means for ejecting printed copy sheets from the sheet transporting mechanism.

it is a further object of the present invention to prevent printing operaticns when no copy sheet is transported by the sheet transporting mechanism.

it is a further object of the present invention to provide a sheet transporting mechanism which completes a single cycle of operation during each revolution of the printing roller of the duplicating machine.

it is a further object of the present invention to automatically return the sheet transporting mechanism to an intitial position when a lag occurs between the printing roller and the sheet transporting mechanism.

With these objects in View, the present invention mainly consists in a duplicating machine which comprises, in

combination, a rotary printing roller; a pressure roller cooperating with the printing roller and defining with the same a printing line; a gripper device extending in axial direction of the rollers and being adapted to grip and release a copy sheet; first actuating means for actuating the gripper device to grip a copy sheet and being located on one side of the rollers; second actuating means for actuating the gripper device to release the copy sheet and being located on the other side of the rollers; transporting means for transporting in an operational cycle the gripper device from the first actuating means through the printing line to the second actuating means and back to the first actuating means whereby the copy sheet is transported through the printing line and printed between the rollers; and motion transmitting means connecting the printing roller with the transporting means for moving the transporting means through one operational cycle during each revolution of the printing roller.

tates Patent 0" 2,828,689 Patented Apr. 1, 1958 'ice The motion transmitting means preferably include a lost motion device for interrupting the movement of the transporting means while the first actuating means actuates the gripper device to grip the copy sheet.

in the preferred embodiment of the present invention, the transporting means include flexible loop-shaped elements, such as chains, guided over wheels, and supporting the gripper device. The gripper device preferably includes gripper means for gripping the copy sheets, ejector means'for ejecting the printed copy sheets, and sensing means for determining whether or not a copy sheet has been gripped by the gripper means. In the event that the sensing means indicate that no copy sheet has been gripped by the gripper means, the pressure roller is moved away from the printing roller so that no printing operation is carried out.

The first actuating means preferably include actuating lever means which are controlled by cam means connected to the printing roller for rotation therewith. The second actuating means preferably include a cam face which engages the gripper means and the sheet ejector means for actuating the same at the delivery station at which the printed sheets are deposited.

in a modified embodiment of the present invention, the transporting means are driven from the pressure roller, which in turn is operated from the printing roller by frictional engagement. An additional drive means for the sheet transporting mechanism is provided in this modified embodiment for positively returning the sheet transporting means to an initial position even if a lag between the sheet transporting means and the printing roller occurs due to insufficient frictional engagement.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. 'The invention iself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. l is a fragmentary side view, partly in section, of a duplicating machine provided with a sheet transporting mechanism according to the present invention;

Fig. 2 is a horizontal sectional view taken on line 2-2 in Fig. 1;

Fig. 3 is a fragmentary plan view of 2. according to the present invention;

Fig. 4 is a cross sectional view taken on line 4-4 in Fig. 3;

Fig. 5 is across sectional view taken on line 5-5 in Fig. 3;

Fig. 6 is a cross sectional view taken on line 6-6 in Fig. 3;

Fig. 7 is a fragmentary sectional view taken on line 7-7 in Fig. 8 and illustrating motion transmitting means for driving the sheet transporting mechanism from the printing roller;

Fig. 8 is a horizontal sectional view taken on line 8-8 in Fig. 7; v

Fig. 9 is a sectional view taken on line 9-9 in Fig. 8;

Figs. l0, ll, 12, and 13 are fragmentary cross sectional views on an enlarged scale illustrating consecutive operational positions of the gripper device during the release of a printed copy sheet at the delivery station;

Fig. 14 is a fragmentary side view illustrating a mechanism for moving the pressure roller to an inoperative position when no copy sheet is inserted into the gripper means at thefeeding station; and

Fig. 15 is a fragmentary side view of a duplicating machine for printing selected portions of the printing foil on the copy sheet, and provided with a sheet transporting gripper device the eccentric shaft the pressure roller is moved between an inoperative position spaced from the printing roller 1 and a printing position in which the pressure roller presses a copy sheet against the printing foil 3. The printing roller is driven from a motor 6 through pulleys 8 and 9,-a belt 7, and gears 10 and 11. The pressure roller 4 is driven from the printing roller 1 by frictional engagement.

The sheet transporting mechanism 12 according to the present invention comprises a gripper device 17 and transporting means for moving the gripper device 17. The

transporting means include elongated flexible loop-shaped chains 13 which pass about pairs of chain wheels 14, and 16. The pair of chain wheels 14 is fixedly mounted on the shaft 18. The pair of chain wheels 15 is loosely mounted on the end portions 4:: of the pressure roller 4 and are free to turn relative to the pressure roller. The pair of chain wheels 16 is fixedly connected to the delivery roller 19.

The sheet transporting mechanism 12 is driven through gears 20, 21 and through the segment gears 22 and 23, which are shown in greater detail in Figs. 7 and 8. The arrangement is such that the motion transmitting means 20, 21, 22 and 23 turn the chain wheels-14 at such rotary speed that the sheet transporting mechanism 12 completes one cycle of operation during each revolution of the printing roller 1. A cycle of operation is completed when the gripper device 12 has moved from its initial position illustrated in Fig. 1 along the loop-shaped path defined by the chains 13 and has returned to its initial position.

At the feeding station at which copy sheets are supplied to the gripper device, a holding means holds a stack of copy sheets 25. A projecting guide member 25b guides the uppermost sheet 26 toward the gripper device 17 when the feeding roller means 24 pushes sheet 26 toward the gripper device. A further guide plate 25c is provided for properly guiding the copy sheet 26. This arrangement, however, is not an object of the present invention. As best seen in Fig. 2, the shafts 18, 5 and .62 are turnably supported in the side walls 51 of the machine frame.

The gripper device 17 which transports the copy sheet 26 from the feeding station, through the printing line in the plane Q R and to the delivery station, is shown in greater detail in Figs. 36. An elongated support 27 is mounted at its ends on the chains 13 and carries a shaft 28 which pivotally supports the gripper means 29, the sheet sensing means 30, and the ejector means 31. A plurality of ejector means 31 and of gripper means 29 are provided on the support 27. A cam 37 is secured to one end of the support 27 The shape of cam 37 is best seen in Figs. 10 and ll, and its function will be described with respect to these figures hereinafter.

The sheet gripper means 29 are clearly shown in Fig. 4,

and include a lever pivoted on shaft 28, and a spring 32 which urges the lever 29 in clockwise direction. The free end-of the gripper 29 engages an oblique face 27a of the support 27 which is provided with recesses and 36 which will be described with reference to Figs. 5 and 6. The support 27 has projections 27b which together with the face 27a form a guide for properly positioning the leading edge of the copy sheet 26. Each pivoted gripper 29 has a cam follower projection 29a.

A sensing means is alsoprovided on the gripper device 17-, and is best seen in Fig. 5. Asensing lever 30 is pivotally mounted on the shaft 28, and is urged by a spring 33 to turn in clockwise direction into the associated recess 39' in the support 27. In Fig. 5, a copy sheet 26 is shown to be positioned on the oblique face 270, so that the sensing lever 30 cannot move into the associated recess 30' and is held by the copy sheet 26 in a slightly raised position. The other end of the sensing lever 30 is provided with a cam follower projection 3'60. The ejector means for ejecting a copy sheet at the delivery station are best seen in Fig. 6. An ejector lever 31 is urged by a spring 35 to turn in clockwise direction into a recess 36 in the face 27a of the support 27. It will be noted that the ejector lever 31 is located underneath the copy sheet 26 in its normal position. The rear end of the ejector lever 31 is provided with a cam follower projection 31a, and it will be understood that if the ejector lever 31 is turned in counterclockwise direction, the leading edge of the copy sheet 26 will be raised and pushed out of the guide defined by the face 27a and the projections 276. However, such operation is only possible when the gripper means 29 are turned in counterclockwise direction to release the copy sheet 26, as will be described hereinafter. The ends of the ejector levers 31 are connected by an ejector bar 34 in order to assure a more reliable action of the ejector means.

The motion transmitting means by which the sheet transporting mechanism is driven from the printing roller 1 in the embodiment of Fig. 1, is shown in greater detail in Figs. 7 and 8. The printing roller 1 has a tubular extension 39 on which the segment gear 23 is turnably mounted. The segment gear 23 has a peripheral portion along which no teeth are provided, and the toothless gap is bridged by a curved locking projection 41 which is arranged axially displaced with respect to gear 23 and is fixedly secured to the same. The gear 22 meshes with gear 23, and is driven by the same as long as the teeth of the gear 23 engage teeth of the gear 22 before the gap of the segment gear 23 is opposite the gear 22 during turning movement of the printing roller 1. The gear 22 carries a locking member 42 which is provided with a concave locking face engaged by the convex locking face of the gear 23 during passage of the toothless gap past the gear 22. The gear 22 is mounted on a pin 43 and drives through gear 21 the gear 20 which is fixedly connected to the shaft 18 which carries the drive chain wheels 14. Gear 21 is mounted on a pin 44.

The toothless gap in the segment gear 23 is so positioned that the chain wheels 14 come to a standstill while the gripper device 17 is located at the feeding station in the position illustrated in Fig. 1. The length of the locking projection 41 determines the time of standstill of the sheet transporting mechanism during a single revolution of the printing roller 1. It will be understood that the gears 22, 23 together with the locking elements 41 and 42 constitute a lost-motion device interrupting the operation of the motion transmitting means by which the printing roller 1 is connected to the chain wheels 14.

In order to assure that a copy sheet transported by the gripper device 12 is placed in proper position for printing from the printing foil attached to the printing roller it is necessary to connect the motion transmitting means for driving the'sheet transporting mechanism with the printing roller in a predetermined position of the printing roller 1. A coupling is provided for this purpose, and is shown in Fig. 9. The segment gear 23 carries a pin 47 about which a lever 46 is turnablc. The lever 46 has an upper arm 48 which is connected to the gear 23 by spring 57, and a lower angularly displaced arm 56 provided with a cam face 56a. A lever which is fixedly connected to the eccentric shaft 5 of the pressure roller 4, engages the arm 56 of lever 46 and holds the same in the illustrated position against the action of spring 57/ When lever 55 is turned in clockwise direction, the pressure roller approaches the printing roller, and

asespss at the same time the cam face 56a permits counterclockwise movement of lever 46 under the action of spring 57. The lever arm 48 carries a pin 49 which projects into a slot 50b of a coupling member 50. A coupling ring 59 is fixedly connected to the printing roller 1, and has a coupling recess 58 which cooperates with the coupling member 50. The coupling member 56 also cooperates with a member 53 pivotal about a pin 52, and urged by a spring 54 to turn into engagement with a stop 53a. When the machine is at a standstill, the lever 46 is in the illustrated position, and the coupling member 50 engages the member 53. When the lever 55 is turned, as previously described, the lever arm 48 moves to the left in Fig. 9 and pushes the coupling point 50a of the coupling member 50 into the recess 58 whereby the gear 23 is coupled to the coupling ring 59 and thereby to the printing roller 1. The above described elements constitute coupling means for coupling the printing roller 1 to the motion transmitting means which drives the sheet transporting means 12. When after one revolution of the printing roller 1 the arm 56 of lever 46 is again engaged by lever 55 in its previous position illustrated in Fig. 9, the coupling member is Withdrawn from the coupling recess 58, and the coupling means is released.

The lever 55 is connected by a link 60 with a lever 61, so that every time lever 55 with eccentric shaft is turned, the eccentric shaft 62 is also turned whereby the delivery roller and the chain wheels 16 are shifted. Thereby the tension of the chains 13 is maintained, although the position of the chain wheels 15 is changed by operating the lever 55 and thereby the pressure roller 15.

Due to the fact that the relative position between the driving printing roller 1 and the sheet transporting means 12 is determined by the coupling means 50, 58, 59, the gripping device 17 is moved through the plane Q-R when the recess 1a of the printing roller 1 is located opposite the pressure roller 4. Thereupon the gripping device carries the copy sheet further so that the copy sheet is properly positioned with respect to the printing foil 3 during the printing operation. Lever 55 may be operated at will by manual operation or by foot control.

While the gripper device 12 is held at a standstill by the lost- motion device 40, 41, 42, 22, 23, the gripper means 29 are operated by first actuating means. Referring again to Fig. 1, a cam 84 is mounted on the shaft 2 for rotation with the printing roller 1. Levers 81 are mounted on the shaft 43 and cooperate with the cam follower portions 29a of the gripper means 29. A cam follower lever 82 is connected to shaft 43, and carries a cam follower roller 83 cooperating with cam 84. When the gripper device is opposite the feeding station, the cam 84 effects opening of the gripper means 29 by levers 81 so that a copy sheet 26 can be inserted into the gripper means whereupon the cam 84 releases the cam follower 83 so that i the levers 81 are returned to an inoperative position by the springs 85. Thereupon the springs 32 effect closing of the gripper means 29 resulting in clamping of the copy sheet 26. The feeding station illustrated in Fig. 1 is automatic, but is also possible to insert the copy sheets into the gripper means by manual operation.

After the gripper means 29 have gripped a copy sheet 26, the transporting means 13 carry the sheet through the printing line and towards the delivery roller 19. The delivery station in which the copy sheets are ejected from the sheet transporting means, will now be described with reference to Figs. -13.

Levers 65 are mounted on a shaft 66 and are urged by springs 67 to press the rollers 64 against the delivery roller 19. At th end of shaft 66, a lever 65 is provided which carries a roller 64' which cooperates with cam 37 as best seen in Fig. 11.. Levers 68 are mounted on shaft 66 and carry cam means 69 on a rod 70. A uniform. spacing between the cam means 69 and the delivery roller 19 is assured by the levers 71 regardless of the turning of the eccentric shaft 62 of the delivery roller 19.

When the gripper device 17 approaches the delivery roller 19, earns 37 engage the rollers 64 and gradually turn the shaft 66 together with the levers 65 and rollers 64. Consequently, the gripper device 17 can pass under the rollers 64 without being engaged by the same. When the gripper device 17 moves further to the position shown in Fig. 12, the cam follower portions 29:: of the gripper means 29, the cam follower portions 30a of the sensing means 30, the cam follower portions 31a of the ejector means 31, 34 are engaged by the cam means 69. During further movement of the gripper device 17 the-cam means 69 opens the gripper means, the sensing means, and the ejector means as shown in Fig. 13. The gripper means 29 and the sensing means 30 release the copy sheet, While the ejector means 31, 34 push the copy sheet out of the opened gripper means and sensing means. The delivery roller 19 and the roller 64 move the copy sheet 26 further on until the copy sheet is deposited at a suitable table. Further movement of the transporting means 13 return the gripper device to the position shown in Fig. 1 in which the gripper device is again provided with another copy sheet. The gripper device 17 completes a full cycle of operation in the same time as the printing roller 1 completes one revolution. In the initial position of the gripper device illustrated in Fig. l, the lost- motion device 41, 42 again effects stopping of the gripper device until a sheet is supplied and gripped by the gripper means. Thereupon, the motion transmitting means between the printing rollers and the chain wheels 14 effect further movement of the sheet transporting device for the next cycle of operation.

In the event that no sheet is supplied to the gripper de vice 17 in the position shown in Fig. 1, the gripper device would move without a sheet between the printing roller 1 and the pressure roller 4 which might result in printing on the pressure roller. To prevent such disadvantageous occurrence, means are provided according to the present invention to move the pressure roller 4 to an inoperative position if no copy sheet is gripped by the gripper device 17.

The sensing means 34), which have been described with reference to Figs. 3 and 5, accomplish this function. In the event that no copy sheet 26 is gripped by the gripper means 29, the sensing means 39 will move from the position shown in Fig. 5 into a position in which the free end of the sensing means 30 is located in the recess 30, while the rear end, and more accurately the cam follower projection She will project upwardly. Fig. 14 shows the position I of the gripper device 17 in which a copy sheet is gripped. The gripper device II in Fig. 14 has not gripped a copy sheet, and consequently has assumed the position in which the rear end 30a of the sensing means 30 projects upwardly. it will be understood that only one gripper device-17 is provided although two are shown in Fig. 14 to explain the operation.

A lever 72 is mounted turnable about the pin 73 which is supported in the frame 51 of the machine. In the position Ii, the rear end 39a of the sensing means moves along a path which crosses the lever 72, so that the lever 72 is pivoted in clockwise direction. In the event that a sheet is gripped by the gripper means, the sensing means are held in the position I, and the lever 72 is not actuated. Lever '72 operates a contact 74, and closes the circuit of a relay 75 when the sensing means pivot lever 72 due to the fact that no copy sheet is gripped by the gripper means. The relay 75 attracts the lever 77 which is pivotal about the pin 76. Lever 77 is normally urged by spring 78 into a position in which a catch portion at the end thereof engages the end of a lever 79 and holds lever 79 in the position illustrated in Fig. 14 against the action of spring 80. When the relay 75 releases the lever 79 by retracting the catch lever 77, the lever 79 turns into the position illus- 'trated in dash and dot lines in Fig. 14, thereby turning shaft 5. Since shaft is an eccentric shaft, the pressure roller 4 is moved 'to a position spaced from the printing roller 1, so that no printing can take place. Consequently it is prevented that the pressure roller is pressed against the surface of the printing roller 1, or against the surface of a printing foil 3 thereon, if no copy sheet is gripped by the gripper means. The sheet transporting mechanism continues its movement until the gripper device 17 has returned to initial position I where it is stepped by the atclon of the lost-motion device described with reference to Fig. 9.

In the modified embodiment illustrated in Fig. 15, the sheet transporting mechanism according to the present invention is applied to a duplicating machine which is capable of printing selected portions of the printing foil 3 onto the copy sheet. In a machine of this type, the pressure roller 4 is moved into engagement with the printing roller to print a head portion from the printing foil, and is then moved out of engagement with the printing roller while an undesired portion of the printing foil 3 passes through the printing line. When a desired portion of the printing foil 3 is again placed opposite the pressure roller the pressure roller is automatically moved into engagement with the printing foil to printsuch other selected portions from the printing foil. This arrangement is known, and not an object of the present invention. It is however necessary that the sheet transporting means 12 stop While an undesired portion of the printing foil 3 passes through the printing line, so that the next following desired portion of the printing foil is printed adjacent to the preceding selected portion on the copy sheet.

The pressure roller is driven by frictional engagement from the printing roller 1, and consequently stops when the pressure roller 4 is moved out of engagement with the printing roller 1. It is necessary that the sheet transporting mechanism 12 according to the present invention also stops when an undesired portion of the printing foil 3 passes through the printing line while the pressure roller 4 is retracted to its inoperative position. Consequently, the sheet transporting mechanism illustrated in Fig. 15 is not driven directly from the printing roller 1, but through the pressure roller 4. Thereby, the sheet transporting mechanism stops when the pressure roller 4 is retraced and not driven from the printing roller, and consequently the sheet remains in the same position until an undesired portion of the printing foil 3 has passed through the printing line, whereupon the next following desired portion of the printing foil 3 is printed on the copy sheet adjacent the previously printed portion.

Fig. 15 shows the gripping device 17 in open position at the feeding station of the machine. When a copy sheet 26 is inserted into the opened gripper means, the coupling means 45 is actuated by manual operation as described with reference to Fig. 9 so that the continuously rotating printing roller 1 turns through the coupling ring 59, not shown in Fig. 15, the segment gears 85 and 87. In the embodiment illustrated in Fig. 15, the chain wheels 15 are fixedly connected to the pressure roller 4, and turn with the same. mechanism 12 moves only during rotation of the pressure roller 4.

The gripper means of the gripper device 17 are opened and closed to receive and hold a copy sheet, and then move toward the printing roller and the counterpressure roller. After the gripper device 17 has moved through the open clamping passage which is constituted by the members 88 and 89, it moves through the printing line and passes through the recess 38 in the printing drum 1. The movable clamping member 89 is turnable about a pin 91) and is operated through a linkage 91, 92, and a cam follower lever 93 turnable about a pin 95. The cam follower lever 93 carries a cam follower roller 94 cooperating with a cam 96 which turns together with the printing roller.

Consequently, the sheet transporting connected to the toggle levers A gear 97 is connected to the coupling means which couples the gear 97 for one revolution to the printing roller by moving the coupling member into the recess 53 of the coupling ring 59 which is fixed on the printing roller 1. 7 These coupling means have been described in great detail with reference to Fig. 9, and some of the members have been omitted in Fig. 15 for the sake of clarity.

A setof cams turns with the shaft 101, which is connected by the gears 99 and 93 to the gear 97. Consequently, the cam unit 100 is driven from the printing roller as long as the coupling means is engaged.

The coupling ring 59 carries a friction segment 102, which 'frictionally engages the pressure roller 4 after the operation of the toothed segment 86 has been terminated, so that the pressure roller 4 in operative position, and the sheet transporting mechanism 12 are moved. A shaft 103 carries a plurality of cam follower levers 104 having cam follower rollers 105. Springs 106 are connected to the levers 104 and urge the rollers into engagement with the cam unit 100. The pressure roller 4 is mounted on shaft 5 which is supported on lever means 111. Lever means 111 are turnable about a shaft 11.2 so that the pressure roller 4 is free to move between an inoperative position spaced from the printing roller and an operative position engaging the printing roller. A pair of toggle levers 108 and 109 are pivotally connected to each other, and connected at the ends thereof to the shaft 5 and to a fixed shaft 110, respectively. Link members are 103 and 109 and to the levers 104. Consequently, the toggle levers 108, 109 are operated by the cam unit 100 to move the pressure roller between inoperative and operative positions.

The cam unit 100 includes duplicating cams 120, cams 121, for printing the head portion of the printing foil 3, and cams 122 for printing selected lines from the printing foil 3. The pair of toggle levers 108, 109 is operated in accordance with the projections on cams 120, 121 and 122, and consequently the pressure roller is moved to operative position whenever a desired portion of the printing foil is located in the printing line. Such desired portions are preselected by suitably adjusting the positions of the cams 121 and 122.

During rotation of the cam unit 100, a spring mechanism 119 is wound up. For this purpose, a winding cam 123 is provided in the cam unit 100, and pivots during rotation thereof a lever 125 by engaging the roller 124. Pivotal movement of the lever 125 results in shifting of the link 127 whereby the lever 128 is turned about a shaft 129, and the link 130 turns the lever 131 about shaft 132. Lever 131 has a segment-shaped gear portion which meshes with the winding gear 133 of the spring mechanism 119. Consequently, the spring mechanism 119 is wound up while the cam unit 100 rotates. A turning of the gear 133 in counterclockwise direction is prevented by the pawl 115 which is turnably mounted on a pin 134 and is urged by spring 117 to engage ratchet teeth on the ratchet wheel 118, which is connected to the gear 133. As long as pawl 115 engages the ratchet teeth of the ratchet wheel 118, the wound up spring mechanism cannot return. Ratchet pawl 115 has a pin 116 which projects into a slot of the link 107. After the head portion, and selected line portions of the printing foil 3 have been printed, the release cam 113 engages the roller of the feeler lever 104, and pulls, together with toggle levers 108, 109, the pin 116 to the left so that the ratchet pawl 115 releases the ratchet wheel 118, permitting the spring mechanism to return to its unwound position. Since the spring mechanism 119 is connected to the shaft 18 which carries the chain wheels 14, the sheet transporting mechanism is moved, and the arrangement is such that the gripper device 17 is returned to its initial position at the feeding station. During such operation of the spring mechanism 119, the gripper device passes over the delivery roller 19, where the actuating means described with reference to Figs. 10-13 open the gripper means and actuate the ejector means, so that the printed copy sheetis deposited. The advantage of tie above described arrangements resides in that the gripper device is returned to initial position, even if it has lagged due to interruption of friction behind the printing roller 1 during a revolution of the same.

The clamping means 38, 5'39 are operated from the cam 96 to clamp a copy sheet while the pressure roller 4 is spaced from the printing roller 1. As previously described, the sheet transporting means are at standstill while the pressure roller 4 is spaced from the printing roller 1.

It will be understood that each of the elements described above, or two or more toget, er, may also find a useful application in other types of sheet transporting mechanism differing from the types de sribed above.

While the invention has been illustrated and described as embodied in a sheet transporting mechanism for a rotary duplicating machine and including gripper means for positively moving a copy sheet around a continuous endless path and through the printing line, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a duplicating machine, in combination, a rotary printing roller; a pressure roller cooperating with said printing roller and defining with the same a printing line; a gripper device extending in axial direction of said rollers and being adapted to grip and release a copy sheet; first actuating means for actuating said gripper device to grip a copy sheet and being located on one side of said rollers; second actuating means for actuating said gripper device to release the copy sheet and being located on the other 1 side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means whereby the copy sheet is transported through said printing line and printed between said rollers; and motion transmitting means connecting said printing roller with said transporting means for moving said transporting means through one operational cycle during each revolution of said printing roller, said motion transmitting means including a lost-motion device for interrupting the movement of said transporting means while said first actuating means actuate said gripper device to grip the copy sheet.

2. In a duplicating machine, in combination, a rotary printing roller; a pressure roller cooperating with said printing roller and defining with the same a printing line; a gripper device extending in axial direction of said rollers and being adapted to grip and release a copy sheet; first actuating means for actuating said gripper device to grip a copy sheet and being located on one side of said rollers; second actuating means for actuating said gripper device to release the copy sheet and being located on the other side or" said rollers; transporting means for transporting in an operational cycle sai gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means whereby the copy sheet is transported through said printing line and printed between said rollers; and motion transmitting means connecting said printing roller with said transporting means for moving said transportingmeans through one operational cycle during each revolution of said printing roller, said motion transmitting means including manually operated coupling means movable to a released position for separating said transporting means from said rotary printing roller, said motion transmitting means including a lost-motion device for interrupting the movement of said transporting means while said first actuating means actuate said gripper device to grip the copy sheet.

3. In a duplicating machine, in combination, a rotary printing roller adapted to support a printing foil; a pressure roller cooperating with said printing roller and defining with the same a printing line; a gripper device including an elongated support extending in axial direction of said rollers, and gripper means mounted on said support movable between an open position and a closed position for gripping a copy sheet, said gripper means tending to assume said closed position; first actuating means for moving said gripper means to said open position and being located on one side of said rollers; second actuating means for moving said gripper means to said open position and being located on the other side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means so that a copy sheet inserted into said gripper means in said open position is gripped by said gripper means moving to said closed position, transported through said printing line, and re leased by said gripper means moved to said open position by said second actuating means; and motion transmitting means connecting said printing roller with said transporting means for moving said transporting means through one operational cycle during each revolution of said printing roller, said motion transmitting means including a lost motion device for interrupting the movement of said transporting means while said gripper means moves to said open position under the action of said first actuating means and returns to said closed position for gripping a copy sheet. 7

4. In a duplicating machine, in combination, a rotary printing roller adapted to support a printing foil; a pressure roller cooperating with said printing roller and defining with the same a printing line; a gripper device including an elongated support extending in axial direction of said rollers, and gripper means mounted on said support movable between an open position and a closed position for gripping a copy sheet, said gripper means tending to assume said closed position; first actuating means for moving said gripper means to said open position and being located on one side of said rollers; second actuating means for moving said gripper means to said open position and being located on the other side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means, said transporting means including a pair of flexible loop-shaped elements respectively attached to the ends of said elongated support, and a plurality of wheel means for guiding said flexible loop-shaped elements so that a copy sheet inserted into said gripper means in said open position is gripped by said gripper means moving to said closed position, transported through said printing line, and released by said gripper means moved to said open position by said second actuating means; and motion transmitting means connecting said printing roller with said wheel means for moving said flexible loop-shaped elements through one operational cycle during each revolution of said printing roller, said motion transmitting means including a lostmotion device for interrupting the movement of said flexible loop-shaped elements while said gripper means moves to said open position under. the action of said first actuating means and returns to said closed position for gripping a copy sheet.

5. In a' duplicating machine, in combination, a rotary printingrroller adapted to support a printing foil; a pressure roller cooperating with said printing roller and defining with the same a printing line; a gripper device including an elongated support extending in axial direction of said rollers, sheet ejector means mounted on said elongated support and being movable between an inoperative position and an operative position, and gripper means mounted on said support movable between an open position and a closed position for gripping a copy sheet. said gripper means tending to assume said closed position; first actuating means for moving said gripper means to said open position and being located on one side of said rollers; second actuating means for moving said gripper means to said open position and said sheet ejector means to said operative position, said first actuating means being located on the other side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means so that a copy sheet inserted into said gripper means in said open position is gripped by said gripper means moving to said closed position, transported through said printing line, released by said gripper means moved to said open position by said second actuating means, and ejected by said sheet ejector means; and motion transmitting means connecting said printing roller with said transporting means for moving said transporting means through one operational cycle during each revolution of said printing roller, said motion transmitting means including a lost-motion device for interrupting the movement of said transporting means while said gripper means moves to said open position under the action of said first actuating means and returns to said closed position for gripping a copy sheet.

6. In a duplicating machine, in combination, a rotary printing roller adapted to support a printing foil; a pressure roller cooperating with said printing roller and defining with the same a printing line; a gripper device including an elongated support extending in axial direction of said rollers, sheet ejector means mounted on said elongated support and being movable between an inoperative position and an operative position, and gripper means mounted on said support movable between an open position and a closed position for gripping a copy sheet, said gripper means tending to assume said closed position; first actuating means for moving said gripper means to said open position and being located on one side of said rollers; second actuating means for moving said gripper means to said open position and said sheet ejector means to said operative position, said first actuating means being located on the other side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means, said transporting means including a pair of flexible loop-shaped elements respectively attached to the ends of said elongated support, and a plurality of wheel means for guiding said exible loop-shaped elements so that a copy sheet inserted into said gripper means in said open position is gripped by said gripper means moving to said closed position, transported through said printing line, released by said gripper means moved to said open position by said second actuating means, and ejected by said sheet ejector means; and motion transmitting means connecting said printing roller with said wheel means for moving said flexible loop-shaped elements through one operational cycle during each revolution of said printing roller, said motion transmitting means including a lost-motion device for interrupting the movement of said flexible loop-shaped elements while said gripper means moves to said open position under the action of said first actuating means and returns to said closed position for gripping a copy sheet.

7.'In a duplicating machine, in combination, a rotary printing roller adapted to support a printing foil, a pressure roller cooperating with said printing roller, said pressure roller being movable between a printing position defining with said printing roller a printing line and an inoperative position spaced from said printing roller; a gripper device including an elongated support extending in axial direction of said rollers, gripper means mounted on said support movable between an open position and a closed position for gripping a copy sheet, said gripper means tending to assume said closed position, and sheet sensing means mounted on said clongated support, said sheet sensing means tending to assume a first position and being movable to a second position and adapted to be held in said second position by a copy sheet gripped by said gripper means; first actuating means for moving said gripper means to said open position and being located on one side of said rollers; second actuating means for moving said gripper means to said open position and being located on the other side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means so that a copy sheet inserted into said gripper means in said open position is gripped by said gripper means moving to said closed position, transported through said printing line, and released by said gripper means moved to said open position by said second actuating means; control means connected to said pressure roller for moving the same between said operative and inoperative positions and including a control member located between said first actuating means and said rollers, said sheet sensing means in said first position engaging said control member and actuating said control means during movement of said transporting means for shifting said pressure roller to said inoperative position of the same; and motion transmitting means connecting said printing roller with said transporting means for moving said transporting means through one operational cycle during each revolution of said printing roller, said motion transmitting means including a lost motion device for interrupting the movement of said transporting means while said gripper means moves to said open position under the action of said first actuating means and returns to said closed position for gripping a copy sheet. a

8. In a duplicating machine, in combination, a rotar printing roller adapted to support a printing foil; a pressure roller cooperating with said printing roller, said pressure roller being movable between a printing position defining with said printing roller a printing line and an inoperative position spaced from said printing roller; a gripper device including an elongated support extending in axial direction of said rollers, gripper means mounted on said support movable between an open position and a closed position for gripping a copy sheet, said gripper means tending to assume said closed position, and sheet sensing means mounted on said elongated sup port, said sheet sensing means tending to assume a first position and being movable to a second position and adapted to be held in said second position by a copy sheet gripped by said gripper means; first actuating means for moving said gripper means to said open position and being located on one side of said rollers; second actuating means for moving said gripper means to said open position and being located on the other side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means, said transporting means including a pair of flexible loop-shaped elements respectively attached to the ends of said elongated support, and a plurality of wheel means for guiding said flexible loop-shaped elements so that a copy sheet-inserted into said gripper means in said open position is gripped by said gripper means moving to said closed po sition, transported through said printing line, and released by said gripper means moved to said open position by said second actuating means; control means connected to said pressure roller for moving the same between said operative and inoperative positions and including a control member located between said first actuating means and said rollers, said sheet sensing means in said first position engaging said control member and actuating said control means during movement of said transporting means for shifting said pressure roller to said inoperative position of the same; and motion transmitting means connecting said printing roller with said wheel means for moving said flexible loop-shaped elements through one operational cycle during each revolution of said printing roller, said motion transmitting means including a lost motion device for interrupting the movement of said flexible loop-shaped elements while said gripper means moves to said open position under the action of said first actuating means and returns to said closed position for gripping a copy sheet.

9. In a duplicating machine, in combination, a rotary printing roller adapted to support a printing foil; a pressure roller cooperating with said printing roller, said pressure roller being movable between a printing position defining with said printing roller a printing line and an inoperative position spaced from said printing roller; a gripper device including an elongated support extending in axial direction of said rollers, sheet ejector means mounted on said elongated support and being movable between an inoperative position and an operative position, gripper means mounted on said support movable between an open position and a closed position for gripping a copy sheet, said gripper means tending to assume said closed position, and sheet sensing means mounted on said elongated support, said sheet sensing means tending to assume a first position and being movable to a second position and adapted to be held in said second position by a copy sheet gripped by said gripper means; first actuating means for moving said gripper means to said open position and being located on one side of said rollers; second actuating means for moving said gripper means to said open position and said sheet ejector means to said operative position, said first actuating means being located on the other side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means, said transporting means including a pair of flexible loopshaped elements respectively attached to the ends of said elongated support, and a plurality of wheel means for guiding said flexible loop-shaped elements so that a copy sheet inserted into said gripper means in said open position is gripped by said gripper means moving to said closed position, transported through said printing line, released by said gripper means moved to said open position by said second actuating means, and ejected by said sheet ejector means; control means connected to said pressure roller for moving the same between said operative'and inoperative positions and including a control member located between said first actuating means and said rollers, said sheet sensing means in said first position engaging said control member and actuating said control means during movement of said transporting means for shifting said pressure roller to said inoperative position of the same; and motion transmitting means connecting said printing roller with said wheel means for moving said flexible loop-shaped elements through one operational cycle during each revolution of said printing roller, said motion transmitting means including a lost-motion device for interrupting the movement of said flexible loop-shaped elements while said gripper means moves to said open position under the action of said first actuating means and returns to said closed position for gripping a copy sheet.

10. In a duplicating machine, in combination, a rotary printing roller adapted to support a printing foil; apressure roller cooperating with said printing roller and defining with the same a printing line; a gripper device including an elongated support extending in axial direction of said rollers, sheet ejector means mounted on said elongated support and being movable between an inoperative position and an operative position, and gripper means mounted on said support movable between an open position and a closed position for gripping a copy sheet, said gripper means tending to assumesaid closed position; first actuating means for moving said gripper means to said open position and being located on one side of said rollers; second actuating means for moving said gripper means to said open position and said sheet ejector means to said operative position, said first actuating means being located on the other side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means, said transporting means including a pair of flexible loop-shaped elements respectively attached to the ends of said elongated support, and a plurality of wheel means for guiding said flexible loop-shaped elements so that a copy sheet inserted into said gripper means in said open position is gripped by said gripper means moving to said closed position, transported through said printing line, released by said gripper means moved to said open position by said second actuating means, and ejected by said sheet ejector means; and motion transmitting means connecting said printing roller with said Wheel means for moving said flexible loop-shaped elements through one operational cycle during each revolution of said printing roller, said motion transmitting means including a lost-motion device for interrupting the movement of said flexible loop-shaped elements while said gripper means moves to said open position under the action of said first actuating means and returns to said closed position for gripping a copy sheet; said motion transmitting means including manually operated coupling means movable to a released position for separating said transporting means from said rotary printing roller.

11. In a duplicating machine, in combination, a rotary printing roller adapted to support a printing foil; a pres sure roller cooperating with said printing roller and defining with the same a printing line; a gripper device including an elongated support extending in axial direction of said rollers, sheet ejector means mounted on said elongated support and being movable between an inoperative position and an operative position, and gripper means mounted on said support movable between an open position and a closed position for gripping a copy sheet, said gripper means tending to assume said closed position; first actuating means including cam means connected to said printing roller for rotation therewith'a'nd a cam follower lever for moving said gripper means to said open position and being located on one side of said rollers; second actuating means for moving said gripper means to said open position and said sheet ejector means to said operative position, said first actuating means being located on the other side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means, said transporting means including a pair of flexible loop-shaped elements respectively attached to the ends of said elongated support, and a plurality of wheel means for guiding said flexible loop-shaped elements so that a copy sheet inserted into said gripper means in said open position is gripped by said gripper means moving to said closed position, transported through said printing line, released by said gripper means moved to said open position by said second actuating means, and ejected by said sheet ejector means; and motion transmitting means connecting said printing roller with said wheel means for moving said flexible loop-shaped elements through one operational cycle during each revolution of said printing roller, said motion transmitting means including a lost-motion device for interrupting the movement of said flexible loop-shaped elements while said gripper means moves to said open position under the action of said first actuating means and returns to said closed position for gripping a copy sheet.

12. In a duplicating machine, in combination, a rotary printing roller adapted to support a printing foil; a pressure roller cooperating with said printing roller, said pressure roller being movable between a printing position defining with said printing roller a printing line and an inoperative position spaced from said printing roller; a gripper device including an elongated support extending in axial direction of said rollers, sheet ejector means mounted on said elongated support and being movable between an inoperative position and an operative position, gripper means mounted on said support movable between an open position and a closed position for gripping a copy sheet, said gripper means tending to assume said closed position, and sheet sensing means mounted on said elongated support, said sheet sensing means tending to assume a first position and being movable to a second position and adapted to be held in said second position by a copy sheet gripped by said gripper means; first actuating means including cam means connected to said printing roller for rotation therewith, and a cam follower lever for moving said gripper means to said open position and being located on one side of said rollers; second actuating means for moving said gripper means to said open position and said sheet ejector means to said operative position, said first actuating means being located on the other side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means, said transporting means including a pair of flexible loop-shaped elements respectively at tached to the ends of said elongated support, and a plurality of wheel means for guiding said flexible loopshaped elements so that a copy sheet inserted into said gripper means in said open position is gripped by said gripper means moving to said closed position, transported through said printing line, released by said gripper means moved to said open position by said second actuating means, and ejected by said sheet ejector means; control means connected to said pressure roller for moving the same between said operative and inoperative r positions and including a control member located between said first actuating means and said rollers, said sheet sensing means in said first position engaging said control member and actuating said control means during movement of said transporting means for shifting said pressure roller to said inoperative position of the same; and motion transmitting means connecting said'printing roller with said wheel means for moving said flexible loop-shaped elements through one operational cycle during each revolution of said printing roller, said motion transmitting means including a lost-motion device for interrupting the movement of said flexible loop-shaped elements while said gripper means moves to said open position under the action of said first actuating means and returns to said closed position for gripping a copy sheet.

13. In a duplicating machine, in combination, a rotary printing roller; a pressure roller cooperating with sai printing roller and defining with the same a printing line; a gripper device extending in axial direction of said rollers and being adapted to grip and release a copy sheet; first actuating means for actuating said gripper device to grip a copy'sheet and being located on one side of said rollers; second actuating means for actuating said gripper device to release the copy sheet and being located on the other side of said rollers; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line to said second actuating means and back to said first actuating means whereby the copy sheet is transported through said printing line and printed between said rollers, said transporting means including a drive gear; and motion transmitting means connecting said printing roller with said transporting means for moving said transporting means through one operational cycle during each revolution of said printing roller, said motion transmitting means including a segment gear having a toothless gap in the periphery thereof, a convex locking projection fixedly connected to said segment gear and bridging said gap, another gear meshing with said segment gear, a concave locking member fixedly connected to said other gear and cooperating with said looking projection to stop said other gear while said toothless gap of said segment gear passes said other gear, said other gear meshing with said drive gear of said transporting means, said gears being arranged in such relative position that the movement of said transporting means is interrupted while said first actuating means actuate said gripper device to grip the copy sheet.

14. In a duplicating machine, in combination, a rotary printing roller adapted to support a printing foil; a pressure roller cooperating with said printing roller and defining with the same a printing line; a gripper device including an elongated support extending in axial direction of said rollers, and gripper means mounted on said support movable between an open position and a closed position for gripping a copy sheet, said gripper means tending to assume said closed position; a cam fixedly connected to one end of said elongated support; first actuating means for moving said gripper means to said open position and being located on one side of said rollers; second actuating means for moving said gripper means to said open position and being located on the other side of said rollers; a pair of delivery rollers located between said second actuating means and said printing line, one of said delivery rollers being movable between a retracted position and a position engaging the other delivery roller for transporting a copy sheet; transporting means for transporting in an operational cycle said gripper device from said first actuating means through said printing line, to said delivery rollers, to said second actuating means and back to said first actuating means so that a copy sheet inserted into said gripper means in said open position is gripped by said gripper means moving to said closed position, transported through said printing line, and released by said gripper means moved to said open position by said second actuating means, said cam on said support shifting said one movable delivery roller to said retracted position during passage of said gripper device between said delivery rollers.

15. In a duplicating machine, in combination, a rotary printing roller; 3. pressure roller cooperating with said printing roller; a movable supporting means supporting said pressure roller for movement between a printing position defining with said printing roller a printing line and an inoperative position spaced from said printing roller; operating means for operating said movable supporting means and being driven from said printing roller; an elongated gripper device extending in axial direction of said printing roller and being adapted to grip and release a copy sheet; first actuating means for actuating said gripper device to grip a copy sheet and being located on one side of said printing line; second actuating means for actuating said gripper device to release the copysheet and being located on the other side of said printing line; transporting means for transporting said gripper, device in an operational cycle during each revolution of said printing roller from said first actuating means through-said printing line to said second actuating means and back to the first actuating means, said transporting means including a pair of flexible loop-shaped elements respectively attached to the ends of said gripper device, and a plurality of wheel means for guiding said flexible loop-shaped elements, one of said wheel means being connected to said pressure roller for rotation therewith; and motiontransmitting means including a friction drive connecting said printing roller with said pressure roller in said printing position of the latter and a pair of segment gears respectively connected to said printing roller and to said pressure roller for rotation therewith, and meshing with each other, said segment gears being effective during part of each revolution of said printing roller While said pressure roller is in said inoperative position, said motion transmitting means further including a spring mechanism connected to said printing roller to be wound up by the same, said spring mechanism including a rotary member con nected to another of said wheel means, ratchet means preventing return movement of said spring mechanism, release cam means driven from said printing roller, and

References Cited in the file of this patent UNlTED STATES PATENTS 2,257,490 Aberle Sept. 30, 1941 2,280,799 Davidson Apr. 28, 1942 2,374,668 Davidson May 1, 1945 2,387,750 Davidson Oct. 30, 1945 2,436,765 Davidson Feb. 24, 1948 2,542,073 Aberle Feb. 20, 1951

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