US2758539A

US2758539A - Sheet strippers for rotary duplicators

Info

Publication number: US2758539A
Application number: US300208A
Authority: US
Inventors: Ritzerfeld Wilhelm; Ritzerfeld Gerhard
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-08-08
Filing date: 1952-07-22
Publication date: 1956-08-14
Anticipated expiration: 1973-08-14

Description

Aug. 14, 1956 Rn-zERFELD ETAL 2,758,539

SHEET STRIPPERS FOR ROTARY DUPLICATORS Filed Jfily 22, 1952 2 Sheets-Sheet 1 Fly. 1

Inventors:

LHEI-rq RITZERFELD 5 R ARD fiITzERFEl-D Aug. 14, 1956 w. RITZERFELD ETAI- SHEET STRIPPERS FOR ROTARY DUPLICATORS 2 Sheets-Sheet 2 Filed July 22, 1952 ,FTN

Inventors.- RITZER FELD WILHE'LM @ERHARD RITZER FELD BY. W

United States Patent Otfice 2,758,539 Patented Aug. 14, 1956 2,758,539 SHEET STRIPPERS FOR ROTARY DUPLICATORS Wilhelm Ritzerfeld, Berlin-Dahlem, and Gerhard Ritzerfeld, Berlin-Grunewald, Germany Application July 22, 1952, Serial No. 300,208 Claims priority, application Germany August 8, 1951 11 Claims. (Cl. 101-91) The present invention relates to rotary duplicators.

It is an object of the invention to provide an improved rotary duplicator of the type allowing to reproduce texts separated from each other on a printing form by more than one line in immediate juxtaposition on a copy sheet.

In connection with such duplicators, it is necessary for the movements of the copy sheets to be printed to be exactly matched to movements of different individual elements of the duplicators. Accordingly, it is a more specific object of the invention to provide simple and yet reliable means for co-ordinating such movements.

It is a further object of the invention to provide improved means for reliably separating copy sheets from the printing drum while the same is rotated from the end of one text to the beginning of another text separated from the first text on the printing form by more than one line.

These and other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of an embodiment of the invention when read in conjunction with the accompanying drawings, in which:

Fig. 1 is a side view of a rotary duplicator of the invention in its initial position;

Fig. 2 is a similar side view of the rotary duplicator of Fig. 1 in its position in which the printing of a first text on a copy sheet begins; and

Fig. 3 illustrates a section along the line 3-3 of Fig. 2, which for clarity has been expanded.

The printing drum 1 shown in the drawings is rotatable in the direction of the inscribed arrow together with a printing form 3 attached to the printing drum 1 by a clamping device 2. The term copy sheet as used herein is intended to embrace paper sheets, cards, labels, and the like on which a text is to be reproduced by the duplicator. On the movement of the printing drum 1, the rotation of a cam disc 4 for controlling the print of a first text (hereinafter called heading) and the rotation of a cam disc 5 for controlling the print of a subsequent text (hereinafter called the lines) are dependent, the cam discs 4 and 5 being linked to the printing drum 1 by means of gears that are known per se and are therefore not shown for clarity. The print of the heading on a copy sheet 6 is usually effected by means of stamps or the like printing matrices arranged on the printing drum at the vicinity of the clamping device 2, while the print of the lines is usually derived from a mirror script original prepared in the usual manner by a typewriter and constituting the printing form 3.

' Cams of the cam discs 4 and 5, co-operate with a

toggle lever arrangement

9, 10, 11, 12, 13, which moves a counter-pressure roller 8 mounted in supporting levers 7 towards and away from the printing drum 1 for cooperation therewith in timed relationship to the rotation of the printing drum 1. After the leading end of the copy sheet 6 has passed the line 14 where the printing takes place, the leading end of the copy sheet 6 is separated from the printing form 3 by strippers 16 keyed to,

and rotatable with, a shaft 15. The rotational move-' ment of the strippers 16 is controlled and effected by a 2 control lever 17 arranged on the same shaft 15. The control lever 17 is operated by a control disc 19 (Figs. 2 and 3) arranged on a shaft 18 of the printing drum so as to rotate bodily with the printing drum.

While the copy sheet 6 is inserted into the rotary duplicator, the strippers 16 engage slots 20, grooves, or the like provided in the periphery of the printing drum 1 and the clamping device 2, as can be seen from Fig. 2.

After the leading end of the copy sheet 6 has passed the line of printing 14, the strippers 16 are rotated by the control disc 19 and the control lever 17 to assume the position indicated in dash-dotted lines in 'Fig. 2 and, thus, separate the leading end of the copy sheet 6 from the printing form 3. After the strippers 16 have been rotated out of the slots 20 or the like by means of the control disc 19 and the control lever 17, the further control of the movement of the strippers 16 is elfected in dependence on the movements of the cam discs 4 and 5. To this end, a control movement initiated by the cam discs 4 and 5 is transferred to a follower 9 of the

toggle lever arrangement

9, 10, 11, 12, 13. To the follower 9, a lug 21 is linked which acts on a rotatable lever 22 mounted rotatably on'the shaft 15. During the movement of the rotatable lever 22, an abutment stud 23 arranged thereon bears against a lever 24 keyed to the shaft 15. As can be seen from Fig. l, the lever 24 then rotates the strippers 16 from the position indicated in dash-dotted lines in which, as likewise indicated in dash-dotted lines, the counter-pressure roller 8 is removed from the printing drum 1, that is to say between the printing of the heading and the printing of the lines, into the position indicated in full lines in which the strippers 16 are out of range of the counter-pressure roller 8 which, now, again presses against the printing drum 1 as indicated in full lines.

A spring 25 arranged between the rotatable lever 22 and the lever 24 fixed to the shaft 15 causes the lever 24 to be permanently urged towards the stud 23 of the rotatable lever 22. During the control of the strippers 16 by the control disc 19 and the control lever 17, the lever 24 is removed from the stud 23, while after the termination of 'this control process the lever 24 is caused by the spring 25 to bear against the stud 23.

In order to hold the copy sheet 6 in its position relative to the line of printing 14 while the counter-pressure roller.

8 is removed from the printing drum 3, clamp springs 27 fixed on a shaft 26 are pressed against the copy sheet 6. This is effected by means of a further control disc 28 (Fig. 1) likewise arranged on the shaft 18 of the printing drum 1 and rotatable therewith. The movement of the further control disc 28 is transferred to the clamp springs 27 by means'of a control lever 29 connected to the shaft 26 (see also Fig. 2).

From the foregoing description, it will be seen that a rotary duplicator has been provided, wherein all the successive operations required for printing a copy sheet from a printing form are controlled in a simple and reliable manner by the movements of the printing drum 1 and the. counter-pressure roller 8 co-operating therewith, the coun-,

ter-pressure roller 8 being moved in timed relationship towards and away from the printing drum 1 carrying the printing form 3 and being mounted in supporting levers 7 and controlled by the toggle lever arrangement '9, 1d, 11, 12, 13, which supporting levers 7 are rotatably mounted. The rotatably arranged strippers 16 engage,

while the latter is beingrotated forwards in order to' bring a next line of' the printing form'into'the printing position so as to be printed on the copy sheet 6 H when the same is again pressed against the printing drum 1 by the ;counter-pressureffroller 8 controlled by the cam discs 4 and 5 and the

toggle lever arrangement

9, 10, 11, 12, 13. In this respect, the provision is of importance of the control disc 19 connected to, and rotatable with, the printing drum 1, which control disc serves to rotate the strippers 16 by means of the control lever 17 and the lever 24 which is rotatably arranged on the shaft and is urged by the action of the spring 25 against the abutment stud 23. I

After the strippers: 16 have become active, that is to say after the copy sheet 6 has been removed from the printing form 3 by the strippers 16, then the control of the said strippers is subsequently effected in dependence on the movements of the counter-pressure roller 8 away from, and towards, the printing drum 1 in such a manner that the rotatable lever 24 supportingthe strippers 16 and arranged on the shaft 15 is linked by means of the connecting lug 21 to the follower 9 sensing the cam discs 4 and 5 for controlling the movements of the counterpressure roller 8 towards and away from the printing drum 1.

Moreover, during the time in which the copy sheet 6 has to be kept separated from the printing form 3 in order to bring the respective line to be printed of the printing form into the printing position, it is necessary for the copy sheet 6 to be kept at rest. This is effected in that the copy sheet 6 is held in its position by clamp springs 27 while the counter-pressure roller 8 is removed from the printing drum 1, the clamp springs 27 being controlled by a further control disc 28 rotating together with the printing drum 1.

It should be clearly understood that the embodiment described and illustrated is given by way of example only. Many modifications, omissions and additions are possible without departing from the spirit of this invention; For example, the clamp springs 27 for holding the copy sheet 6 may be replaced by any other suitable holding device. Again, the

toggle lever arrangement

9, 10, 11, 12, 13 may be replaced by any other suitable linkage.

We claim:

1. A rotary duplicator, comprising, in combination, a rotary printing drum adapted to support a printing form; a counter pressure roller cooperating with said printing drum and adapted to press a copy sheet against the printing form; movable supporting means supporting said counter-pressure roller for movement toward and away from said printing drum; rotary cam means driven from said printing drum and connected to said movable supporting means for moving said counter-pressure roller toward and away from said printing drum during each revolution of the same for printing spaced portions of the printing form in adjacent position on the copy sheet; a movable support; strippers mounted on said movable support adjacent a bight between said drum and said counter pressure roller and being movable toward and away from said printing drum and adapted to separate a copy sheet from the printing drum; first operating means driven from said printing drum in timed relationship with said 'cam means for moving said strippers in timed relationship with said printing drum so as to move the leading edge of a copy sheet away from said printing drum; rotary cam means and to said strippers for moving said strippers in timed relationship with said counter pressure roller so that said strippers move away from said drum and are adapted to separate acopy sheet from said printing drum whenever said counter pressure roller moves away from said printing drum while said printing drum continues rotation for moving, an undesired portion of the printing form past the copy sheet.

2. A rotary duplicator, comprising, in combination, a rotary printing drum adapted to support aprinting form; a counter pressure roller. cooperating with said printing and second operating means connected to said drum and adapted to press a copy sheet against the printing form; movable supporting means supporting said counter pressure roller for movement toward and away from said printing drum; rotary cam means driven from said printing drum and connected to said movable supporting means for moving said counter pressure roller toward arid away from said printing drum during each revolution of the same for printing spaced portions of the printing form in adjacent position on the copy sheet; a turnable supporting shaft; strippers secured to said shaft projecting into a bight between said printing drum and said counter pressure roller; a cam track secured to said printing drum for rotation therewith; a first control lever secured to said supporting shaft and having a free end guided in said cam track so that in predetermined positions of said printing drum said strippers are rocked away from said printing drum in timed relationship with said cam means for separating the leading edge of a copy sheet from the printing drum, and so that in other predetermined positions of said printing drum said cam track releases said free end of said first control lever; a second operating lever secured to said supporting shaft; an operating member freely turnably mounted on said supporting shaft and having an abutment; a spring connecting said second operating lever with said operating member and urging said second operating lever into engagement with said abutment; motion transmitting means connecting said operating member with said cam means and with said movable supporting means of said counter pressure roller in such manner that when said counterpressure roller moves away from said printing drum, said operating member is turned on said supporting shaft so that said spring moves said second control lever to a position corresponding to a movement of said strippers away from said printing drum for separating the copy sheet from said printing drum whenever said counter pressure roller moves away from said printing drum while said printing drum continues rotation for moving an undesired portion of the printing form past the copy sheet.

3. A rotary duplicator comprising, in combination, a rotary printing drum adapted to support a printing form; a counter pressure roller cooperating with said printing drum and adapted to press a copy sheet against the printing form; movable supporting means supporting said counter pressure roller for movement toward and away from said printing drum; rotary control means driven from said printing drum and connected to said movable supporting means for moving said counter pressure roller during each revolution of said printing drum toward and away from said printing drum for printing spaced portions of the printing form in adjacent position on the copy sheet; a movable support; stripper means mounted on said movable support adjacent a bight between said printing drum and said counter pressure roller and being movable toward and away from said printing drum between initial position adapted to engage the leading edge of a copy sheet and a plurality of positions farther spaced from said printing drum for separating the copy sheet from the printing form during rotation of said printing drum; first operating means driven from said printing drum for moving said stripper means in timed relationship with said printing drum out of said initial position so as to move the leading edge of a copy sheet away from said printing drum; and second operating means connecting said rotary control means to said stripper means for moving said stripper means in timed relationship with said counter pressure roller so that said stripper means move between said farther spaced positions toward and away from said printing drum for separating a copy sheet from said printing drum whenever said counter pressure roller moves away from said printing drum while said printing drum continues rotation for moving an undesired portion of the printing form past the copy sheet,

4. A rotary duplicator comprising, in combination, a

rotary printing drum adapted to support a printing form, said rotary printing drum being formed with circumferential grooves; a counter pressure roller cooperating with said printing drum and adapted to press a copy sheet against the printing form; movable supporting means supporting said counter pressure roller for movement toward and away from said printing drum; rotary control means driven from said printing drum and connected to said movable supporting means for moving said counter pressure roller during each revolution of said printing drum toward and away from said printing drum for printing spaced portions of the printing form in adjacent position on the copy sheet; a movable support; stripper means mounted on said movable support adjacent a bight between said printing drum and said counter pressure roller and being movable toward and away from said printing drum between initial position projecting into said grooves in said printing drum and adapted to engage the leading edge of a copy sheet and a plurality of positions farther spaced from said printing drum for separating the copy sheet from the printing form during rotation of said printing drum; first operating means driven from said printing drum for moving said stripper means in timed relationship with said printing drum out of said initial position so as to move the leading edge of a copy sheet away from said printing drum; and second operating means connecting said rotary control means to said stripper means for moving said stripper means in timed relationship with said counter pressure roller so that said stripper means move between said farther spaced positions toward and away from said printing drum for separating a copy sheet from said printing drum whenever said counter pressure roller moves away from said printing drum while said printing drum continues rotation for moving an undesired portion of the printing form past the copy sheet.

5. A rotary duplicator as claimed in claim 4 wherein said movable supporting means include a plurality of articulated levers, one of said articulated levers supporting said counter pressure roller.

6. A rotary duplicator as claimed in claim 5 wherein said rotary control means include a plurality of coaxial cam disks, and wherein one of said articulated levers is a cam follower engaging said cam disks.

7. A rotary duplicator as claimed in claim 4 wherein said movable support is a freely turnable shaft; and wherein said stripper means are secured to said shaft.

8. A rotary duplicator as claimed in claim 4 and including a cam member connected to said printing drum for rotation therewith; a holding means for holding a copy sheet stationary and being located adjacent another bight between said printing drum and said counter pressure roller, said holding means being movable between an operative holding position and an inoperative releasing position; and motion transmitting means connected to said holding means and including a cam follower member engaging said cam member so that said holding means is moved to said operative holding position whenever said counter pressure roller is in a position spaced from said printing drum.

9. A rotary duplicator comprising, in combination, a rotary printing drum adapted to support a printing form; a counter pressure roller cooperating with said printing drum and adapted to press a copy sheet against the printing form; movable supporting means supporting said counter pressure roller for movement toward and away from said printing drum; first control cam means driven from said printing drum; a plurality of articulated levers connected to said movable supporting means and including a cam follower lever engaging said first control cam means for moving said counter pressure roller during each revolution of said printing drum toward and away from said printing drum for printing spaced portions of the printing form in adjacent position on the copy sheet; a turnable shaft; stripper means secured to said shaft and projecting and away from said printing drum between an initial position adapted to engage the leading edge of a copy sheet and a plurality of positions farther spaced from said printing drum; second cam means driven by said printing drum; a cam follower lever secured to said turnable shaft and having a free end engaging said second cam means for moving said stripper means in timed relationship with said printing drum out of said initial position so as to move the leading edge of a copy sheet away from said printing drum; another lever secured to said turnable shaft; an operating member freely turnably mounted on said turnable shaft; an abutment of said operating member engaging said other lever during turning movement of said operating member; spring means connecting said operating member with said other lever for urging the same against said abutment; and a link' connecting said operating member with one of said articulated levers whereby said stripper means are moved in timed relationship with said counter pressure roller between said farther spaced positions.

10. A rotary duplicator comprising, in combination, a driven printing drum adapted to support a printing form and to move the same through a printing line; a counter pressure roller cooperating with said printing drum at said printing line; movable supporting means supporting said counter pressure roller for movement between an operative position engaging printing drum and an inoperative position spaced from said printing drum; supply means for supplying sheets to said printing drum so that said counter pressure roller and said printing drum grip a supply copy sheet along said printing line and transport the same in printing engagement with said printing form only when said counter pressure roller is in said operative position; holding means for maintaining the copy sheet stationary when said counter pressure roller is in said inoperative position; rotary cam means driven from the printing drum so as to turn in timed relationship with said printing form, said cam means engaging said movable supporting means and moving the same and therewith said counter pressure roller automatically and positively during each revolution of said printing drum through a selected cycle of movements from said operative position to said inoperative position when undesired portions of said printing form are moved by said printing drum past said printing line, and again to said operative position for printing desired portions of the printing form on the copy sheet adjacent to matter previously printed by said printing form; a turnable shaft; stripper means secured to said shaft and projecting into a bight between said printing drum and said counter pressure roller; and linkage means connecting said movable supporting means with said turnable shaft for turning said shaft in timed relationship with the movement of said counter pressure roller so that said stripper means separate the copy sheet from said printing drum whenever said counter pressure roller moves away from said printing drum while said printing drum continues rotation thereof.

11. A rotary duplicator as claimed in claim 10 wherein said movable supporting means include a plurality of articulated levers, one of said levers being a cam follower lever engaging said cam means, and wherein said linkage $62118 connect said cam follower lever with said turnable a t. 7

References Cited in the file of this patent UNITED STATES PATENTS 653,762 France Mar. 27, I929