US2039784A

US2039784A - Sheet feed retarding mechanism for printing presses

Info

Publication number: US2039784A
Application number: US19572A
Authority: US
Inventors: William K Eckhard
Original assignee: Individual
Current assignee: CB Cottrell and Sons Co
Priority date: 1935-05-03
Filing date: 1935-05-03
Publication date: 1936-05-05
Anticipated expiration: 1953-05-05

Description

May 5, 1936. W. K. ECKHARD SHEET FEED RETARDING MECHANISM FOR PRINTING PRESSES Filed May Z5, 1955 4 Sheets-Sheet l INVENTOR.

ATTORNEYS May 5, 1936. w. K. ECKHARD 2,039,784

SHEET FEED RETARDNG MECHANISM FOR PRINTING PRESSES Filed May 5, 1935 4 Sheets-Sheet 2 Hw Y@ 1 I mmm mi May 5, 1936- w. K. ECKHARD SHEET FEED RETARDING MECHANISM ,FOR PRINTING PRESSES 4 Sheets-Sheet 3 Filed May 3, 1935 l INVNTOR.

ATTORNEYS I y May 5, 1936. W. K. ECKHARD I 2,039,784

SHEET FEED EETARDING MECHANISM FOR PRINTING PRESSES Filed May 5, 1955 4 sheets-sheet 4 K/Q'I@ INVENTOR.

ATTORNEYS v Patented May 5, 1936 UNITED STATES PATENT GFFICE SHEET FEED RETARDING RIECHANISM FOR PRINTING PRESSES Application May 3, 1935, Serial No. 19,572

6 Claims.

In sheet fed printing presses Where a single mechanism has been used for retarding tlr'e travel of the sheets from the feeder to the front sheet register or stop it has been found diflicult to sufficiently retard the travel of the sheets and deliver them in a normal flat condition because of the high speed of the feeder and the desirability of bringing the sheets down to a standstill at the front sheet register before Ythe sheets are taken by the sheet taking means.

The object of my invention is to obviate this difficulty by providing two coacting sheet straightening and retarding mechanisms located between the feeder and the front sheet register,

the first sheet straightening and Aretarding mechanism operating to receive the sheets from the feeder, straighten them and retard their travel to approximately the surface speed of the sheet taking means, and the second sheet 2,0 straightening and retarding mechanism operating to receive the sheets from the first sheet straightening and retarding mechanism and materially retard their travel on the way to the front register.

My invention more particularly comprises means for feeding sheets to the sheet register at p-rogressively lesser speeds comprising, a sheet feeder adapted to feed the sheets at a faster speed than the surface speed of the sheet taking means, a rst sheet straightening and retarding means including an endless chain carrier having gages adapted to be engaged by the leading edges of the sheets as they are advanced by the feeder, and a second sheet straightening and retarding mechanismincluding a reciprocating carrier having gages pivoted thereto, adapted to be engaged by the leading edges of the sheets as the gages on the rst sheet straightening and retarding mechanism leave the said leading edges of the sheets.

A practical embodiment of my invention is represented in the accompanying drawings, in which Fig. 1 represents in detail top plan so much of a sheet fed rotary printing press and its feeding mechanism as includes my invention, the parts being in the positions they assume when the swinging gages of the second sheet straightening and retarding mechanism are about to take control of the sheet from the gages of the first sheet straightening and retarding mechanism; Y

Fig. 2 represents a side View of the same;

Fig. 3 represents a detail side elevation showing the parts in the` positions they assume as the swinging gages of the second sheet straightening and retarding mechanism leave the sheet with its leading edge engaged by the front sheet register in position to be taken by the grippers 0f the sheet taking means; 5

Fig. l represents a detail side. view of the means for operating the front sheet register;

Fig. 5 represents a detail enlarged top plan View showing the relativeV positions of the gages on the rst and second sheet straightening and 10 retarding mechanisms as the control of the sheets is about to be taken by the swinging gages of the second sheet straightening and retarding mechanism;

Fig. 6 represents a side view of the same; l5

Fig. 7 represents a detail side View of the second sheet retarding mechanism with the parts in the Vpositions they assume when the swinging gages have dropped down out of the sheet path;

Fig. 8 represents a similar View with the parts 20 in the positions they assume as the gages are about to .be swung upwardly into position to receive the leading edge of a sheet from the gages of the first sheet straightening and retarding mechanism; 25

Fig. 9 represents in diagram the two cam means for respectively reciprocating the carriage of the second sheet straightening and retarding mechanism and swinging the gages pivoted to the carriage, the parts being at the lim- 30 its of their forward movements; and

Fig. r10 represents a similar diagram with the parts at the limits of their rearward movements.

The sheet taking'means is herein represented as an impression cylinder denoted by l, its shaft being .denoted by 2, which cylinder is driven at a predetermined surface speed. The tumbler actuated grippers 3 on the cylinder l may be operated in the usual manner by the tumbler cam 4 and its coacting pin 5, to take a sheet from the 10 front sheet register at the proper time; the pin for actuating the tumbler cam for delivering the sheet not being shown herein as it forms no part of the present invention.

The front sheet register may be of any well known or approved construction. In the form herein shown the front sheet stops 6 are-carried by the spring pressed rock lever l, which lever is in turn operated by the spring pressed rock lever 8 which carries a stud or roller 9 contacted by the cam I0 on the cylinder shaft 2 to swing the front sheet stops 6 downwardly out of engagement with the leading edge of the sheet as it is grasped by the cylinder grippers 3. It is obvious that two or more of these front sheet stops are provided to the surface speed of the cylinder I.

properly front register the sheet before it is taken by the cylinder grippers.

Y The means which I have shown forfeeding the sheets at successively reduced speeds to the front sheet stops 6, is constructed, arranged and operated as follows:

The inner end of the endless tape carrier of the sheet feeder is shown, which tape carrier is arranged to feed thesheets at a speed faster than The tapes II of the endless tape carrier pass around the pulleys I2 carried by the cross shaft I3 at the inner end of the carrier.

The rst sheet straightening and retarding mechanism includes two endless chains I4 (one only of which is shown herein) overlapping the endless tape carrier in substantially the plane of the sheet path, which chains are driven at a lesser speed than that of the endless tape carrier, preferably at approximately the surface speed of the cylinder I. These endlessV chains pass around inner and outer sprockets I5 and I6 carried by stud shafts I1 and I8 respectively. 'I'hese chains are provided with alined front sheet gages or hooks I 9 arranged in position to receive the leading edge of the sheet as it is advanced by the sheet feeding tapes II.

The second sheet straightening and retarding Vmechanism includes two carriages 20 (one only of which is shown herein) reciprocating on tracks 2| toward and awayV from the front sheet register stops 6 in substantially the plane of the sheet path. The said reciprocating carriages 20 are provided with swinging spring pressed front sheet gages or hooks V22 pivoted thereto to be swung Y into and out of the sheet path. 'I'hese front gages slower than that of the said gages I9, and rapidly retard the travel of the sheet until its leading edge reaches the front sheet register stops 6.

' The means for reciprocating each carriage 2|) of the second sheet straightening and retarding mechanism comprises a rotary cam 23 mounted on the cross shaft 24, the face of which cam is contacted by a stud or roller 25 carried by a spring pressed rock lever 26. This rock lever 26 is vconnected by a rod 2'I t'o another rock lever 28 which in turn is connected by a rod 29 to the carriage 20. It willbe understood that the face of the cam 23 is so shaped that at the time the gages 22 receive the leading edge of the advancing sheet from the gages I9 the carriages 20 will be traveling slightly slower than the gages I9. Immediately after gages 22 have received the leading edge of the advancing sheet the carriages 20 are decelerated so that the leading edge of the Vadvancing sheet reaches the front register or sheet stop at a greatly reduced speed. The means for swinging each of the gages 22 into'and out of the sheet path includes a stud or roller 30 carried by the gage,.which'stud or roller is caused to travel in an endless path by providing a cam groove 3| in the side of the tracks 2|, which` cam groove opens at its inner and outer ends through the top Vof the track. 'I'hese cam groove openings are so arranged that as the carriage 20 reaches the inward limit of its sliding movement the stud or roller 30 Will drop into the cam groove 3I and thus swing the gages 22 out of the sheet path. A plate spring 32 located in the cam groove` 3| is so positioned and shaped that the stud or roller 30 will force thefree end of the spring laterally out of the way on the outward sliding movement of the carriage and will permit the spring to snap back to its normal position as the carriage reaches the limit of its said outward movement. The stud or roller 30 will be caused to ride up out of the cam groove on the inclined outer edge of the spring 32 as the carriage is started on its inward sliding movement. This will swing the gages 22 upwardly into the sheet path in position to receive the leading edge of the advancing sheet from the gages on the endless chains of the first sheet straightening and retarding mechanism. Each endless chain I4 (there are preferably two) is driven through the

gears

33, 34 from the cross shaft 35. This cross shaft 35 is operatively connected to the cam shaft 24 through the train of

gears

36, 31, 38, 39, 40, 4I. The cross shaft I3 for the pulleys I2 at the inner end ofthe sheet feeding endless tape carrier is operatively connected to the cam shaft 24 through the gears 42, 43, 44, 45 and 46. The gear 4I on the cam shaft 24 is operatively connected through the gears 41 and 48 to the gear 49 on the cylinder I. Y

It will be understood that the sheet feeding mechanism herein shown and described is to be be used in connection with the usual side registering and sheet detecting mechanisms (not shown herein).

It is 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 myiinvention, 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 printing press, a sheet taking means, a sheet register and means for feeding sheets theretoV at progressively lesser speeds comprising, a sheet feeder adapted to feed the sheets at a faster speed than the surface speed of the sheet taking means, a first sheet straightening and retarding mechanism traveling at a lesser surface speed than the sheet feeder and adapted to receive the sheets from the sheet feeder and retard their travel to approximately the surface speed of the sheet taking means, and a second sheet straightening and retarding mechanism traveling at a lesser surface speed than the first sheet straightening and retarding mechanism and adapted to receive the sheets from the first sheet straightening and retarding mechanism and to materially retard their travel on the way to the sheet register.

2. In a printing press, a sheet taking means, I

a sheet register and means for feeding sheets thereto at progressively lesser speeds comprising, a sheet feeder adapted to feed the sheets at a faster speed than the surface'speed of the sheet taking means, a first sheet straightening and retarding mechanism having gages traveling in a looped path at a lesser' surface speed than the sheet feeder and adapted to receive the sheets from the sheet feeder and retard their travel to approximately the surface speed of the sheet taking means, and a second sheet straightening and retarding mechanism having gages also traveling in a looped path at a lesser surface speed than the first sheet straightening and retarding mechanism and adapted to receive the a sheet register and means for feeding sheets thereto at progressively lesser speeds comprising, a sheet feeder adapted to feed the sheets at a faster speed than the surface speed of the sheet taking means, a first sheet straightening and retarding mechanism including endless chains having gages traveling at a lesser surface speed than the sheet feeder and operable to receive the sheets from the sheet feeder and retard their travel to approximately the surface speed of the sheet taking means, and a second sheet straightening and retarding mechanism having gages traveling at a lesser surface speed than the rst sheet straightening and retarding mechanism and operable to receive the sheets from the first sheet straightening and retarding mechanism and to materially retard their travel on the way to the sheet register.

4. In a printing press, a sheet taking means, a sheet register and means for feeding sheets thereto at progressively lesser speeds comprising, a sheet feeder adapted to feed the sheets at a faster speed than the surface speed of the sheet taking means, a first sheet straightening and retarding mechanism including endless chains having gages operable to receive the sheets from the sheet feeder and retard their travel to approximately the surface speed of the sheet taking means, and a second sheet straightening and retarding mechanism including reciprocating carriages having swinging gages adapted to receive the sheets from the rst sheet straightening and retarding mechanism and still further retard their travel.

5. In a printing press, a sheet taking means, a sheet register and means for feeding sheets thereto at progressively lesser speeds comprising, a sheet feeder, a rst sheet straightening and retarding means including endless chains having gages operable to receive the sheets from the sheet feeder and retard their travel, and a second sheet straightening and retarding mechanism including reciprocating carriages having swinging gages adapted to receive the sheets from the first sheet straightening and retarding mechanism and still further retard their travel, rotary cam means being provided for reciprocating the said carriages and additional cam means being provided for guiding the carriage gages in their movements into and out of the sheet path.

6. In a printing press, a sheet taking means, a sheets register and means for feeding sheets thereto at progressively lesser speeds comprising, a sheet feeder adapted to feed the sheets at a faster speed than the surface speed of the sheet taking means, a rst sheet straightening and retarding mechanism including endless chains having gages operable to receive the sheets from the sheet feeder and retard their travel to approximately the surface speed of the sheet taking means, and a second sheet straightening and retarding mechanism including reciprocating carriages having swinging gages adapted to receive the sheets from the first sheet straightening and retarding mechanism and still further retard their travel, rotary cam means being provided for reciprocating the said carriages and additional cam means being provided for guiding the carriage gages in their movements into and out of the sheet path.

WILLIAM K. ECKHARD.