US1941093A

US1941093A - Sheet feeding mechanism for printing machines

Info

Publication number: US1941093A
Application number: US319815A
Authority: US
Inventors: Irving A Hunting
Original assignee: Irving Trust Co; R Hoe and Co Inc
Current assignee: Irving Trust Co; R Hoe and Co Inc
Priority date: 1928-11-16
Filing date: 1928-11-16
Publication date: 1933-12-26
Anticipated expiration: 1950-12-26

Description

SHEET FEEDING MEGHANISM FOR PRINTING MACHINES Dec. 26, 1933.

Dec. 26, 1933. x, A. HUNTING SHEET FEEDING MECHANISM FOR PRINTING MACHINES Filed Nov. 16, 1928 5 Sheets-Sheet 2 mvEN-ron l z/f' Dec. 26, 1933. A. HUNTING 1,941,093

SHEET FEEDING MECHANISM FOR PRINTING MACHINES Filed Nov. 16, 1928 5 Sheets-Sheet 3 INVENTGR Dec. 26, 1933. I l. A. HUNTING 1,941,093

SHEET FEEDING MECHANISM FOR PRINTING MACHINES Filed Nov. 16. 1928 5 Sheets-Sheet 4 INVEN'T'QF!v Dec. 26, 1933.

i. A. HUNTING SHEET FEEDING MECHANISM FOR PRINTING MACHINES Filed NOV. 16. 1928 5 Sheets-Shea?l 5 INVEN'I'QR Patented Dec.. 26, 1933 UNITED STATES PATENT oFFlcE SHEET FEEDING MECHANISM FOR PRINTING MACHINES pany, receiver Application November 18, 1928 Serial No. 319,815

7 Claims.

'I'he invention herein disclosed relates to feeding devices for printing machines adapted to print on sheet metal, pasteboard and similar materials. Printing machines of this class have heretofore been made with a feed table on which the operator places a sheet to be printed, a sheet guide and suitable forwarding mechanism which serves to convey the sheet from the feed table to the printing cylinders. In these machines the sheet guide is in alignment with the bite of the cylinders and a pusher engages the rear edge of the sheet to move it forward to the cylinders. In order that the pusher does not obstruct the sheet as it passes from the feed table to the sheet guide, the feed table is placed on a higher level and the sheet in passing from the feed table to the sheet guide is projected forward and drops on the sheet guide in front of the pusher. The invention disclosed herein constitutes an improvement in feeding mechanism of this class, for the feed table is here placed in alignment with the sheet guides and a mechanism is provided that removes the pusher from the p-..th of the oncoming sheet. From the time the sheet starts from the feed table, until it is printed, it is at all times, rigidly held and its motion perfectly controlled. It is thus possible to obtain accurate register in the printing when the invention disclosed herein is used.

In addition to being used with printing machines that are fed manually, this invention is also applicable to machines that are equipped with automatic feeders.

An object of the invention is to provide a feeding mechanism for a printing machine of the class described in which the motion of the sheet will be perfectly controlled during the time it is passing from the feed table or from the feeder to the printing cylinders.

Another object of the invention is to provide a feeding mechanism that will present the sheet to the cylinders in a manner to effect accurate register of the printing.

It is also an object of the invention to provide a feeding mechanism of generally improved construction, whereby the device will be simple, durable and inexpensive in construction, as well as convenient, practical, serviceable and efficient` in its use.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts, and in the details of construction hereinafter described and claimed, it

being understood that various changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

Figure 1 of the drawings is a side view of a portion of a printing machine showing the improved sheet feeding device and mechanism by which it is operated, the parts being shown in the position they occupy when a sheet is being fed into the bite of the printing cylinders.

Figure 2 is a view similar to Figure 1, but showing the parts as they appear when a sheet is being forwarded along the sheet guide.

Figure 3 is a sectional view on the line 3-3 70 of Figure 1 as viewed in the direction of the arrow.

Figure 4 is a detail side view of the pusher which forwards the sheet to the printing cylinders.

Figure 5 is a back view of the pusher as seen in the direction of arrow 5 in Figure 4; and

Figure 6 is a side view in outline of a printing machine of this class equipped with an automatic feeder.

Referring'to the drawings, 11 and 11 indicate the main side frames of a printing machine and 12 a support for a feed table 13. A sheet guide 14 has one of its ends in horizontal alignment with the feed table and the other end in alignment with the bite of the

printing cylinders

15 and 16, it being understood that 15 indicates a cylinder carrying the voffset blanket commonly used for this class of work, and 16 indicates the impression cylinder having grippers 1'7, that 90 are provided with registering faces or stops 17' which engage the front edge of the sheet. These registering grippers are secured to the shaft 18 and are operated by the cam 19, secured to the frame 11. This cam acts on the roller 20 car- 95 ried on arm 21 which is also secured to shaft 18.

Forwarding rollers

22 and 23 are connected together by the gear train 24, and may be driven by a chain which passes around the

idlers

25 and 26, and is driven by the sprocket 27, connected to the gear 28, meshing with the gear 29 on the main shaft 30.

Drop rollers

31 and 32 are carried in bell crank levers 33 and 34, pivoted respectively at 35 and 36 in the members 3'7 and 38. The

thumb nuts

39 and 40, 105 serve to adjust the position of the drop rollers4 with relation to the

members

37 and 38, which are secured to the shafts 41 and 42, and thus adjust the pressure of the drop rollers against the sheet being forwarded.

' described and indicated at '72.

Arm 43 is secured to shaft 42 and connected by link 44 with arm 45, pivoted on the stud l46 and carrying roller 4'7, which engages with cam 48, on the main shaft 30. Similarly arm 49 is secured toshaft 41 and connected by link 50 with arm 51 which as shown on Figure 3 is also pivoted on stud 46, and carries roller 52, which engages with cam 53 also on the main shaft 30. Arm 49 is also connected by the link 54 with arm 55, secured to -shaft 56.' This shaft also carries the sheet stop 57.

The pusher 58, of which one or more may be used is pivoted on the rod 59, secured to member 60, which slides on the rod 61. It will be understood that a similar member and rod are used at the other side of the machine.

The pusher arm 58 is maintained in operative position by the spring 58a carried on the rod 58h, one end of which is pivotally connected to the arm 58, while the other end passes freely through an adjustable bushing 58e, screw threaded into the member 58e, secured to a shaft hereinafter 'Ihe free end of the rod 58h is threaded and provided with lock nuts 58d. The pusher arm is thus yieldingly held in position and the lock nuts and the bushing provide means to adjust the position of the pusher arm and the tension of the spring.

One end of the rod 61 is pivoted on a Xed shaft 62, and the other end slides in suitable ways in the bracket 63, secured to the frame. A pin 64 serves to connect the rod 6l with a link 65, connected to one arm of the bell crank lever 66, the other arm of whichis connected by link 6'7 to one arm of bell crank lever 68, while the other arm carries the roller 69, which engages the cam '70, secured to the main shaft 30. It will be understood that the motion imparted to the lever 68 by the cam '70 results in alternately raising and lowering the pusher mechanism carried on the cross rod 59.

The members 60 are reciprocated along the rods 61 by means which consist of lugs '71, loose on the shaft '72, and held in place by washer '73 and screws '74. Rods '75 are adjustably locked to the lugs '7l by nuts '76, and connected to the arms 7'7, secured to the shaft '78. The arm '79 is also secured to this shaft and carries the roller which engages the grooved cam 81.

The front drops 82, are secured to the shaft 83, to which the arm 84 is also fastened, and link 85 connects the arm 84 to one end of the bell crank lever 86, the other end of the lever having a roller 8'7, in engagement with the cam 88, secured to the main shaft 30. The sheet stops are thus moved from the positions shown in Figure 2 to that shown in Figure l.

Side guide mechanism indicated at 89 is operated by bell crank levers 9G, links 91 and bell crank levers 92 which carry rollers 93 in engagement with cams 94.- One of these side guides is provided at each side of the machine and they serve to properly register the sheet sidewise.

The several cam rollers, except roller 80 which runs in a groove, are held in engagement with their respective cams by springs acting on the arms carrying them. Thus the spring 95 acts on arm 45, 96 on 51,9'7 on 68,98 on 86 and 99 on 92, there being two springs 99, one on each side of the machine.

In operation, a sheet of the material to be printed is placed on the feed table 13 and against the sheet stop 5'7. At the proper time, the stop is raised and the roller 31 descends and presses ing sheet.

the sheet against the moving roller 22 with suicient force that it moves forward along the sheet guide 14. Before the rear edge of the sheet has passed the roller 31, the roller 32 will have descended and press the sheet against the roller 23, thus continuing the forward motion of the sheet.

While the sheet is thus moving forward along the sheet guide, the position of the various elements of the machine are as shown in Figure 2, the pusher mechanism being depressed below the path of the sheet. When the sheet has passed the pusher arm 58, the pusher arm will be raised and moved forward engaging the rear edge of the sheet. At thesame time, the drop roller 32 is raised, and immediately thereafter the front drop 82 is moved out of the path of the oncom- The pusher meanwhile continues its motion, pushing the sheet forward to the printing fcylinders where it may .be engaged by the grippers 1'7 as shown.

In normal operation, the leading edge of the sheet reaches the front drops 82, just as they start tomove forward. At the same instant, the ends of the gripper ngers pass the leading edge of the sheet with but a very small clearance, and then start to close. In closing, the ends of the fingers move over the sheet which is being advanced by the pusher at a rate slightly above the peripheral speed ofthe printing cylinders,

and grip the sheet while it is still being acted on by the pusher.

If one of the forwarding rollers should fail to properly engage a sheet and it is forwarded askew, the leading portion of the forward edge of the sheet will strike one of the front drops 82, and be detained until the action of the pusher brings the sheet into engagement with the other drop also. At that instant, the front drops start to swing forward, and operation continues under normal conditions.

It will thus be understood that the front drops act to obstruct the passage of an improperly fed sheet until the gripper fingers have passed, and are in position to close on it.

As the speed of the pusher is greater than the peripheral speed of the cylinder and as the grippers move toward the sheet in closing, the forward edge of the sheet is pressed against the registering stops of the grippers, and when they close, the sheet is so held that it will be accurately positioned on the cylinder. The pusher arms being spring supported will yield and thus compensate for any variation in the size of the sheet, meanwhile pressing it firmly against the registering stops of the grippers.

It will be noted that from the time the sheet starts from the feed table, until it is printed, that it is constantly held and propelled forward by the feeding mechanism. In consequence the printing is registered with great accuracy.

In cases where an automatic feeder is used the feed table 13 and sheet stop 5'7 are omitted and the sheet is fed directly to the forwarding roller 22 by the sheet forwarding mechanism of the automatic feeder. Such an arrangement is shown in Figure 6, which is an outline drawing showing an automatic feeder operatively connected to a printing machine of this class. The feeder is indicated generally by the numeral 100. The feeder mechanism takes the sheets singly from the pile 101, forwards them along the guides 102, and presents them to the forwarding roller 22 of the printing machine in the proper timed relation to the movements of the machine, so there is no pause in the travel of the sheet from the time it is taken from the pile until it is printed.

Figure 6 also shows an elevating table indicated at 103 on which a pile of sheets may be placed when they are to be fed to the machine manually.

What I claim is:

l. The combination with a cylinder having a plurality of registering grippers for aligning a sheet of relatively stiff material, of a sheet feeding device having a sheet guide, a feed table in alignment therewith, a reciprocating pusher having an arm adapted, during its forward stroke,'to engage the rear edge of a sheet and advance it along the guide to the grippers, forwarding rollers arranged to advance the sheet along the guide and into position to be engaged by the pusher arm, and means to depress the pusher arm beneath the guide during its return stroke.

2. In a printing machine of the class described, a feed table, a sheet guide, means to engage a sheet near its leading edge and forward it from the feed table and along the guide, a second forwarding means to which the sheet is forwarded by the first named means and which uninterruptedly continues the forwarding movement, a pusher which acts on the sheet after it passes the,

second forwarding means, and printing -cylinders having registering grippers to which the sheet is forwarded by the forwarding means'and the pusher.

3. In a printing machine of the class described, a sheet guide, a forwarding roller and a drop roller co-acting therewith to forward a sheet along the guide, a second forwarding roller and a second drop roller co-acting therewith to forward the sheet beyond the zone through which the first named roller forwards it, a pusher which engages the sheet, and printing cylinders having registering grippers to which the sheet is uninterruptedly forwarded by the forwarding rollers and the pusher.

4. In a printing machine of the class described, a feed table, a sheet guide in alignment therewith, a forwarding roller and a drop roller coacting therewith to forward a sheet along the guld a second forwarding roller and a second drop roller co-acting therewith to forward the sheet beyond the zone through which the rst named roller forwards it, a reciprocating pusher which projects above the guide and engages the sheet on its forward stroke and recedes below the guide on its return stroke, and printing cylinders having registering grippers to which the sheet is uninterruptedly forwarded by the forwarding rollers and the pusher..

5. In a printing machine of the class described, printing cylinders having registering grippers, a sheet guide and forwarding rollers in alignment therewith arranged to receive a sheet and advanceit along the guide, and a pusher which engages the rear edge of the sheet and uninterruptedly advances it to the printing cylinders.

6. In a printing machine of the class described, an impression cylinder having a plurality of registering grippers for aligning a sheet of relatively stiff material, sheet guides, a feed table in substantially horizontal alignment with the sheet guides, a forwarding roller and a drop roller coacting therewith to take a sheet from the feed table and forward it along the guides, and a pusher arranged to overtake the sheet as it is moving forward and engage its rear edge to push it forward to the grippers. A

7. In a printing machine of the class described, 105 an impression cylinder having registering grippers, sheet guides, a feed table in substantially horizontal alignment with the sheet guides, a ilrst forwarding roller and a rst drop roller coacting therewith to take a sheet from the feed table and forward it along the guides, a second forwarding roller and a second drop roller coacting therewith to forward the sheet beyond the zone to which the first forwarding roller advanced it, and a pusher arranged to overtake the sheet as it is moving forward and engage its rear edge to push it forward to the grippers.

IRVING A. HUNTING.