US2976036A

US2976036A - Sheet feeder for printing and duplicating machines

Info

Publication number: US2976036A
Application number: US698636A
Authority: US
Inventors: Gericke Erich
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-12-03
Filing date: 1957-11-25
Publication date: 1961-03-21
Anticipated expiration: 1978-03-21

Description

E. GERICKE March 21, 1961 2,976,036

SHEET FEEDER FOR PRINTING AND DUPLICATING MACHINES Filed Nov. 25, 1957 3 Sheets-Sheet 1 FRICH GERICKE.

jm emon' E. GERICKE March 21, 1961 SHEET FEEDER FOR PRINTING AND DUPLICATING MACHINES Filed NOV. 25, 1957 3 Sheets-Sheet 2 Emcn GERICKE lm/emar 6 March 21, 1961 E. GERICKE 2,976,036

SHEET FEEDER FOR PRINTING AND DUPLICATING MACHINES Filed Nov. 25, 1957 3 Sheets-Sheet 5 ERICH GERICNEv fm/errzon' 32 M, ZAJLI- Pam-42 sheet lies flat on the conveyor.

United States Patent SHEET FEEDER FOR PRINTING AND DUPLICAT- ING MACHINES Erich Gericke, 14 Flemmingstrasse, Berlin-Steglitz, Germany The invention relates to a mechanism for feeding sheets into printing machines and is more particularly for use with offset printing machines.

The employment of belt or tape conveyors for feeding sheets into printing machines is already known, the tape conveyor providing a connection between the feeder proper and the printing machine. The conventional type of feeder lifts the sheet from the top of a pile and places its leading edge onto the receiving end of the conveyor, a smoothing roller generally being provided for pressing the sheet onto the conveyor to ensure that the whole of the The ta e conveyor consists of a number of endless belts or tapes all of which move at the same speed towards the printing machine and rollers located at various points press the sheet against the tape conveyor so that the sheet is conveyed to the front lays of the printing machine. Since the feeder proper is already of considerable proportions in relation to a small offset printing machine and the tape conveyor occupies nearly a like amount of space, and Weight, cost, and dimensions of a small offset machine is increased to such an extent as to render such feeders uneconomical, and feeders have been designed and constructed for use with medium-sized and small printing and duplicating machines, which can be positioned sufliciently close to the actual printing and duplicating machine to enable a tape conveyor for conveying the sheets from the pile to the front lays or to the impression cylinder of the machine to be dispensed with.

However, these feeders have the drawback that owing to the small available distance between the pile and the front lays or impression cylinder it is impossible to ensure accurate register of the sheet in the feeding operation, because there is not sufiicient space for the side lay to bring more than the leading half of the side of the sheet into proper register. The side lay cannot affect the rear half of the sheet because the latter still rests on the pile. If only the front part of the sheet is subject to lateral adjustment there is a strong tendency for the front edge of the sheet to back away from the front lays or the impression cylinder, because friction between the rear half 1 of the sheet and the pile prevents the rear half from at 'ice In the accompanying drawings, Figs. 1 and 2 illustrate two alternative forms of construction for solving the problem in the manner described, and

Fig. 3 schematically shows an offset printing machine equipped with a feeder according to the present invention.

In the embodiment of the invention illustrated in Fig. l, the front edge of the sheet on the top of pile 1 is raised by suckers 2. By the co-operation of a cam 3 with its associated cam follower 3a and of a cam 4 with its cam follower 4a, the two shafts 5 and 6 are moved, in such a way that the lifting suckers 2 convey the top sheet to front lays 7 not along a path parallel to the direction of paper feed but, according to the invention, with a simultaneous sideways motion by an amount S in as much as shaft 5 which carries the entire swinging feed mechanism is laterally, i.e.

axially, displaced by the said distance S owing to the cooperation of a lever 9 and a laterally displaceable earn slot 8. Hence, when the sheet comes into contact with the front lays 7 it will have been laterally displaced in relation to the pile by an amount S. Since the whole of the side edge of the sheet will thus overhang the side of the pile by the said amount S, the entire length of this edge is available for adjustment by a side lay 10 with a degree of precision impossible heretofore to achieve, the side lay being traversed by the co-operation of the roller of lever 9 and the cam plate 8, lever 9 being reciprocated by an eccentric 19 mounted on the impression cylinder.

In the form of construction illustrated in Fig. 2, the same result is achieved by an axially displaceable arrangement of a suction rod 13 in a bridge 12 adapted to be reciprocated by a feed lever 14 between the pile 1 of paper sheets and the front lays 7, the slidable lateral displacement of the suction rod 13 being produced by a cam in the form of an oblique vertical ramp '11. The disposition and motion of the side lay 10 is as described with reference to Fig. 1.

Fig. 3 illustrates the feeder according to the invention adapted, with the elimination of a tape conveyor, for use with an offset printing machine which is sheet fed from a pile. The pile is indicated by 1. The sheets are picked from the pile in regular succession and a finger member ensures that the top of the pile remains at a constant level. The sheets are lifted from the pile by suckers 2 of an air suction feeder according to the invention and forwarded to front lays 7. However, simultaneously with its forwarding motion, the air suction feeder displaces the sheet to the side by a predetermined amount 5. The purpose of this lateral displacement has already been described in detail. When the sheet contacts the front lays 7 and has been laterally adjusted by the side lay 10, it is entrained by grippers in an impression cylinder 17 and fed between an offset cylinder 15 and the impression cylinder 17. After having been printed the sheets are again stacked in a pile. To transfer the printing to the paper through the offset cylinder, a plate which is not shown in the drawing but which is located above the ofiset cylinder, is also required. This carries the plate, in this case a thin metal offset plate. This offset metal plate is inked by-inking rollers 18 mounted in an ink distributing frame 16.

Since in offset printing the thin metal plate also has to be moistened, a water fountain is likewise provided from which an immersion roller transfers water to a damping roller and thence to the plate cylinder.

I claim:

A sheet feeder for printing and duplicating machines comprising sheet forwarding means for lifting a sheet of paper from the top of a pile and conveying the same to the front and side lays of the printing machine for adjusting the sheet to accurate register, said forwarding means after the lifting of the sheet from the pile causing a sideways traversing movement in addition to their forward movement and then continuing their forwarding movement until the sheet reaches the front lays, means for moving a side lay transversely to adjust the lateral register of the sheet on the front lays, a swinging shaft on which said forwarding means are mounted, a rod provided upon said forwarding means and grippers mounted on said rod and means for displacing said rod transversely to the direction of forward feed.

References Cited in the file of this patent UNITED STATES PATENTS 1,014,269 Tichborne Jan. 9, 1912 1,095,126 Rogers et a1 Apr. 28, 1914 2,406,847 Neuhart Sept. 3, 1946 2,482,443 Tornros Sept. 20, 1949 2,809,831 Nordquist Oct. 15, 1957