US2803460A

US2803460A - Sheet feeding

Info

Publication number: US2803460A
Application number: US343649A
Authority: US
Inventors: Meltendorf Max
Original assignee: Planeta Druckmaschinenwerk AG
Current assignee: Planeta Druckmaschinenwerk AG
Priority date: 1953-03-20
Filing date: 1953-03-20
Publication date: 1957-08-20
Anticipated expiration: 1974-08-20

Description

1957 M. MELTENDORF 2,803,460

SHEET FEEDING Filed March 20, 1953 2 She ts-Sheet 1 /4 Hang "Aug. 20, 1957 M. MELTENDORF SHEET FEEDING 2 Sheets-Sheet 2 Filed March 20, 1953 INVEN TOR. Y fiI/YX -//z 72-4 905;

United States Patent SHEET FEEDING Max Meltendorf, Radebeul, Germany, assignor to VEB Druckmaschinenwerk Planeta, VVB Polygraph, Radcbeul, Germany Application March 20, 1953, Serial N 0. 343,649

5 Claims. (Cl. 271-58) This invention relates to a method and device for guiding sheets of paper or the like in accurate alignment to printing machines or the like by acting on the first sheet of a continuous stream of overlapping sheets fed to the machine in such manner that each sheet projects somewhat beyond the next.

In known devices of this kind, the minimum spacing of the sheets depends on the time required for registration or, in other words, the time interval during which the sheet is adjusted relative to the front registration gauges, drawn sideways and put in position for accurate feeding incorrect alignment.

In the known devices, the time required for registration is determined by the width of the groove in the sheetcarrying cylinder, since registration can be effected only during the period in which the printing surfaces of the cylinders are not in contact with each other. Large cylinder diameters, however, do not permit a higher output of printed material, since the peripheral speed of the sheets printed cannot be increased beyond a certain empirical value.

It is known to increase the printing speed by commencing with the registration of the second sheet of a sequence of overlapping sheets fed to the machine while this is still partly covered by the first sheet. In one of the known devices of this class an additional gripper arrangement is provided which engages the front edge of the second sheet, partly overlapped by the first sheet, and slowly advances it towards the front registration marks while the first or top sheet is being withdrawn. The front registration marks in this device then act on the upper surface of a sheet, so that the second sheet can only abut against these marks after the first overlying sheet has been fully withdrawn.

The arrangement according to the invention differs from this device insofar as the second sheet is advanced already to the registration marks while it is still covered by the first sheet. Owing to this arrangement, which avoids rapid movements of the grippers and feeding means, the printing speed can nevertheless be considerably increased. Furthermore, the registration of the sheets can be effected at high operating speeds, independently of the width of the groove in the cylinder.

In further accordance with the invention the second sheet is laterally registered as soon as the rear edge of the first sheet has passed the means drawing it forward, whereupon it is engaged by the grippers, brought into registration and drawn forward.

The registration of the second sheet on its front edge is advantageously effected by registration marks operating below, so that the time hitherto required for the complete release of the front registration marks by the first sheet is no longer lost. The new sheet will already be guided up to the front registration marks shortly after the front edge of the sheet engaged by the grippers has left the feed table.

The time available for registration of the front edge of a sheet that has arrived at the front registration marks is therefore relatively long, since the time for the pulling forward of the sheet can be extended to shortly before the swinging grippers close prior to their return.

The time interval covering the closing of the grippers and the beginning of the conveying of the sheet may be relatively short, since it includes merely the operation initiating the engagement of the means for feeding the sheet.

One embodiment of the invention is illustrated, by way of example, in Figs. 1-5 of the accompanying drawings showing five difierent working positions. Figs. 6 and 7 show the actual structure of some of the parts of the device partly in section, while Fig. 8 is a plan view.

On the table 1 advances a succession of

overlapping sheets

2a, 2b the front or leading edges of which project slightly beyond the next. Movable front registering gauges 3 and catching means 4 are disposed opposite the front edge of the table 1. The registering gauges 3 for the front edges of the sheets and the catching means 4 operate from below into the space between the front edge of the table 1 and a rotatable cylinder 9. The catching means 4 has a jaw-like head which projects beyond the plane of the table 1 when it is in the operative position shown in Fig. 1. The mouth of the jaw-like head of the catching means 4 is capable of catching the front edge of the sheet 2a underlying the sheet 2 as shown in Fig. 1. The front registering gauge 3 serves to carry out a front registry of said sheet 2a when it is in the operative position of Fig. 1. Furthermore the top surface of the jaw 4 engages the overlapping sheet 2 for lifting the trailing portion thereof. A side registering device 5 comprising a roller 12 and an insert 14 in the table 1 may cause a side registry of the sheet 2a when the roller 5 is in the position of Fig. 2.

The fingers 6 and the grippers 7 reciprocating about pivots engage the sheet 2a aligned by the front registering gauges 3 and side registering device 5. The grippers 7 lead the sheet 2a to the grippers 8 of the cylinder 9 after the registry of the sheet by the registering means 3 and 5 has been eflected and the feeler 6 is disengaged from the sheet 2a.

According to Fig. l, the first sheet 2 engaged by the grippers 8 of the cylinder 9, is led over the top surface of the jaw of the catching means 4 lifting the sheet, while the fingers 6 and the device 5 remain inoperative. The second sheet 2a then projects into the mouth of the jaw 4 and is aligned by the front registering gauges 3, although it is still partly covered by the first sheet 2.

According to Fig. 2, the rear or trailing edge of the aligned first sheet 2 is disengaged from the side registering means 5 and the rollers 12 thereof lie on the second sheet 2a and commence the lateral displacement thereof.

As shown in Fig. 3, the grippers 7 have engaged the front edge of the sheet 2a after its lateral adjustment has shortly before been completed and the side registering means 5 have -become inoperative again.

Fig. 4 shows the fingers 6 in operation. The front registering gauges 3 have swung downwardly about their pivots, and the catching means 4 previously engaged with the sheet 2a has also moved down, so that the grippers 7 can draw the sheet 2a immediately after the operation of the fingers 6 has come to the end.

In the position shown in Fig. 5 the sheet 2a engaged by the grippers 7 has been taken up by the grippers 8 onto the cylinder 9, and the front registering gauges 3 and the catching means 4 have returned to their operating positions. The sheet 2a has been lifted up slightly by the top surface of the jaw of the catching means 4 to permit the sheet 2b lying beneath it to move freely up to the front registering gauges 3. The sheet 2b abuts with its front edge against the registering gauges 3 before the trailing r 3 end ofthe sheet 20 is drawn by the grippers 8 over the upper surface of thejaw of the catchingmeans 4.v

I claim: 1. A device for feeding sheet material to a printing machine or the'like, comprising in'combination: attable;

for conveyinglsheets in. overlapping relation to oneiarb other, said. table having a front edge, conveyingmeans' spacedfrom said front edge of said table and movable for pulling the leading overlapping'sheet'from said table,

catching means, said catching means beingrreciprocable 10 betweenan inoperativetposition and'an operative posh tion wherein it extends from below into the space, defined by the front edge of the tablet-and said conveying means, into a plane abovevthe plane of said table for lifting the trailing portion of said overlapping sheetiands for'catchingthe leadingedge of the next sheet underlying said first mentionedioverlapping sheet, front registering gauge means reciprocablebetween. an inoperative position and anoperative position wherein said front regis:

tering gauge means extend into said space between the conveying means and the front edge of the table forengaging said leading edge of said underlying sheet and registering same, the operative positions of said catching means. and of said registering gauge means being substantially in alignment with each other, and gripping means being in the shape of a jaw, the upper edge of'said' jaw being capable of engagement with said first mentioned side registering means reciprocable between an inoperative" position and an operative position wherein it engages said next sheet for registering same sidewise.

References Cited in the file of this patent UNITED STATES PATENTS 1,984,588 Liebusch Dec. 18, 1934 1,991,003 Stevens Feb. 12, 1935 2,008,165 Wormser July'16, 1935 2,011,745 Wormser Aug. 20, 1935 2,011,776v Reinartz Aug.[20, 1935" 2,248,079 Harrold July8, 1941 2,317,993 Harrold May4; 1943' 2,377,447 Peyrebrune June 5, 1945 2,466,862 Peyrebrune Apr. 12, 1949 2,642,282 Blackhouse June 16, 1953' FOREIGN PATENTS 36,265 Holland Sept. 16; 1935" 665,104 Germany Sept; 19, 1938'