US2210573A - Sheet feeding mechanism for printing presses - Google Patents

Description

1940- w. K. ECKHARD 2.210.573

lNVENTOR ATTO RN EYS Aug. 6, 1940, w; K EKHARD 2.210.573

SHEET FEEDING MECHANISM FOR PRINTING PRESSES Filed Feb. 9,, 1959 2 Sheets-Sheet 2 INVENTOR ATTORNEYS Patented Aug. 6, 1940 UNITED STATES PATENT OFFICE SHEET FEEDING MECHANISM FOR PRINTING PRESSES Application February 9, 1939, Serial No. 255,371

16 Claims.

In sheet fed printing presses it has heretofore been usual to feed the sheets from the pile onto a conveyer at high speeds and then slow down the sheets to practically nothing at the front sheet stops.

As the printing and consequent feeding speeds have been increased, great difficulty has been encountered in properly feeding and registering the sheets. This has led to the more modern type of overlapping or streamline feeding because of its comparatively low sheet feed speed on the conveyer member of the feeder. One of the disadvantages of the overlapping feeding of the sheets has been the extremely small space left between the tail of the fed-in sheet and the head of the next sheet so that it has been diflicult to correctly convey the sheets to the front stop.

The object of my invention is to obviate this difliculty by speeding-up the free portion of the fed-in sheet to cause the tail of the fed-in sheet to be well spaced from the head of the next sheet, thereby permitting the properv and accurate registering of the said next sheet.

A practical embodiment of my invention is represented in the accompanying drawings:

Fig. 1 represents a detail section through so much of a sheet fed rotary printing press as will give a clear understanding of my invention, the parts being in the positions they assume as the free portion of the fed-in sheet is being speededup to space the tail of the fed-in .sheet from the head of the next sheet.

Fig. 2 represents a detail section taken in the plane of the line II-II of Fig. 1, looking in the direction of the arrows.

Fig. 3 represents a detail section taken in the plane of the line III-III of Fig. 2, looking in the direction of the arrows.

Fig. 4 represents a diagram showing the relative positions of the parts as the grippers on the rotary sheet carrier take the head of the fedin sheet from the sheet stop.

Fig. 5 represents a diagram showing one phase in the speeding-up of the said fed-in sheet.

Fig. 6 represents a diagram showing a succeeding phase in the speeding-up of the fed-in sheet.

Fig. '7 represents a diagram showing a third phase in which the tail of the fed-in sheet has passed out of control of the speed-up means, and the next sheet is being registered and fed to the sheet stop.

The feeder for the overlapping sheets is repre sented diagrammatically by I, and it may be pro vided with the usual sheet retarding device 2 and the front stop or guide 3. These elements may be of any well known or approved construction, and operated in the usual manner. Anexample of these elements and their operation may be found in my United States Letters Patent Nos. 2,039,784 and 2,039,785, granted May 5, 1936. It is therefore believed that a specific description of these elements and their operation will not be necessary herein.

The impression cylinder is denoted by 4 and its sheet grippers by 5. The rotary sheet transfer carrier is denoted by 6 and its grippers by I. These grippers I are arranged to take the head of the fed-in sheet from the sheet stop 3 and transfer it to the grippers 5 on the impression cylinder 4. The impression cylinder may be driven at a predetermined constant surface speed and the rotary sheet carrier may be driven at the same surface speed or at a variable surface speed, if desired, in any well known manner.

While in the present instance the overlapping sheets are shown as being taken from the front sheet stop by the rotary sheet carrier and transferred thereby to the impression cylinder, it is to be understood that this rotary sheet carrier in some instances may itself be the impression cylinder, and the sheets may then be fed directly thereto from the feeder, as clearly shown in my Letters Patent hereinbefore referred to.

The separate means for speeding-up the free portion of the fed-in sheet to space its tail from the next sheet, is herein shown as a rotary suction means which may be constructed, arranged, and operated as follows:

A positively driven hollow suction roll 8 is provided with circumferentially arranged perforations 9, the said roll being rotatably mounted on the stationary hollow inner member [0. This inner member is provided with side ports II which open the interior of the inner member to the perforations 9 in the suction roll as the perforations pass the said ports. An end passage l2 leads from the inner member II] to a suction pump, not shown herein.

The suction roll 8 may be driven to speed up the free portion of the fed-in sheet through the train of gears I3, I4, [5, l6, H, which connects the shaft 18 of the rotary sheet carrier with the shaft l9 of the suction roll.

From the above description it will be seen that the suction roll 8 maintains a constant speed-up pull on the free portion of the sheet as the sheet passes between the suction roll and the rotary sheet carrier.

It will also be understood that the surface speed of the suction roll may be adjusted to insure the tail of the fed-in sheet being spaced the desired distance from the head of the next sheet on the feeder, to permit the proper and accurate registry of the said next sheet before it is taken by the grippers on the rotary sheet carrier.

While I have shown a suction means for speeding-up the free portion of a fed-in sheet, it is evident that any suitable equivalent means may be employed for this purpose.

It is also evident that various changes may be resorted to in the construction, form and arrangement of the several parts without departing from the spirit and scope of my invention, and hence I do not intend to be limited to the particular embodiment herein shown and described, but what I claim is:

1. In a sheet fed rotary printing press, an

overlapping sheet feeder, means for taking the head of the sheet from the feeder, and suction means for speeding-up the free portion of the sheet to space its tail from the head'of the next succeeding sheet and thereby decreasing sheet tension in the sheet taking means.

In a sheet fed rotary printing press, an

overlapping sheet feeder, means for taking the,

head of the sheet from the feeder, and a positively driven suction roll for speeding up the free portion of the sheet to space its tail from the head of the next succeeding sheet and thereby decreasing sheet tension in the sheet taking means.

3. In a sheet fed rotary printing press, an overlapping sheet feeder, a rotary carrier for taking the head of the sheet from the feeder, and suction means for speeding up the free portion of the sheet, to space its tail from the head of the next succeeding sheet and thereby decreasing sheet tension in the rotary carrier.

4. In a sheet fed rotary printing press, an overlapping sheet feeder, a rotary carrier for taking the head of the sheet from the feeder, and a positively driven suction roll for speeding up the free portion of the sheet, to space its tail from the head of the next succeeding sheet.

5. In a sheet fed rotary printing press, an impression cylinder, an overlapping sheet feeder, means for taking the head of the sheet from the feeder and transferring it to the impression cylinder, and suction means for speeding-up the free portion of the sheet, to space its tall from the head of the next succeeding sheet and thereby decreasing sheet tension in the sheet taking means.

6. In a sheet fed rotary printing press, an impression cylinder, an overlapping sheet feeder, means for taking the head of the sheet from the feeder and transferring it to the impression cylinder, and a positively driven suction roll for speeding-up the free portion of the sheet, to space its tail from the head of the next succeeding sheet.

7. In a sheet fed rotary printing press, a front sheet stop, means for feeding overlapping sheets thereto including a sheet retarding device and a rotary carrier for taking the head of the sheet from the front sheet stop, and means for speeding up the free portion of the sheet to space its tail from the head of the next succeeding sheet and thereby decreasing sheet tension in the rotary carrier.

8. In a sheet fed rotary printing press, a front sheet stop, means for feeding overlapping sheets thereto including a sheet retarding device and a rotary carrier for taking the head of the sheet from the front sheet stop, and suction means for speeding up the free portion of the sheet to space its tail from the head of the next succeeding sheet and thereby decreasing sheet tension in the rotary carrier.

9. In a sheet fed rotary printing press, a front sheet stop, means for feeding overlapping sheets thereto including a sheet retarding device and a rotarycarrier for taking the head of the sheet from the front sheet stop, and a positively driven suction roll for speeding-up the free portion of the sheet to space its tail from the head of the next succeeding sheet.

10. In a sheet fed rotary printing press, an impression cylinder, a front sheet stop, means for feeding overlapping sheets thereto including a sheet retarding device and a rotary carrier for taking the head of the sheet from the front sheet stop and transferring it to the impression cylinder, and means for speeding-up the free portion of the sheet to space its tall from the head of the next succeeding sheet. I

.11. In a sheet fed rotary printing press, an impression cylinder, a front sheet stop, means for feeding overlapping sheets thereto including a sheet retarding device and a rotary carrier for taking the head of the sheet from the front sheet stop and transferring it to the impression cylinder and suction means for speeding up the free portion of the sheet to space its tail from the head of the next succeeding sheet.

.12. In a sheet fed rotary printing press, an impression cylinder, a front sheet stop, means for feeding overlapping sheets thereto including a sheet retarding device and a rotary carrier for taking the head of the sheet from the front sheet, stop and transferring it to the impression cylinder, and a positively driven suction roll for speeding-up the free portion of the sheet to space its tail from the head of the next succeeding sheet.

13. In a printing press or like machine, rotary sheet handling means having sheet grippers adapted to receive and advance the leading edge of a sheet, means for presenting the leading edge of a sheet to said grippers, and means effecting non-slipping engagement with the surface of an intermediate portion of a gripped sheet and driving said engaged portion forward at a greater speed than the speed of said grippers.

14. In a printing press or like'machine, a continuously rotating sheet handling cylinder, a rotary sheet transfer device arranged to take the leading edge of a sheet presented thereto, advance said sheet and transfer the same to said cylinder, means forpresenting sheets successively to said transfer device, and means effecting non-slipping engagement with the surface of an intermediate portion of a sheet taken by said transfer device and driving said engaged portion forward at a greater speed than the speed of said leading edge for advancing the rear edge of the sheet at greater speed than the leading edge thereof.

15. In a printing press or like machine, a continuously rotating sheet handling cylinder, a rotary sheet transfer device arranged to take the leading edge of a sheet presented thereto, advance said sheet and transfer the same to said cylinder, means for presenting sheets successively to said transfer device, and means effecting non-slipping engagement with the surface of an intermediate portion of a sheet taken by said transfer device and driving said engaged portion forward at a greater speed than the speed of said leading edge for advancing the rear edge of the sheet at greater speed than the leading edge thereof, said last mentioned means comprising rotary means engaging the sheet and rotated about its own axis with peripheral speed greater than the speed of the forward edge of said sheet. 16. In a sheet fed rotary printing press, an overlapping sheet feeder, means for takingthe WILLIAM K. ECKHARD.

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