US2694363A - Cylinder gripper actuating mechanism - Google Patents

Description

NW. F6, E954 B. a. PAsQumELu CYLINDER GRIPPER ACTUATING MECHANISM 2 Sheets-Sheet. 1

Filed June 9, 1950 I INVENTOR. Bruno B. Pasquz'nel [l1 BY Mg, 444% z..

Mk 1954 B. B. PASQUINELLI CYLINDER GRIPPER ACTUATING MECHANISM 2 Sheets-Sheet 2 Filed June 9, 1950 JNVENTOR. Bra/20 B. Pasquzfnell BY ited States Patent Ofifice 2,694,363 Patented Nov. 16, 1954 CYLINDER omrran ACTUATING MECHANISM Bruno B. Pasquinelli, Chicago, Ill., assignor to Miehle Printing Press & Mfg. Company, Chicago, Ill., a corporation of Delaware Application June 9, 1950, Serial No. 167,204

3 Claims. (Cl. 101-409) This invention relates to printing presses. More particularly, it pertains to improvements in mechanism for actuating the gripper elements on a sheet carrying cylinder whereby the production potential of conventional printing presses can be substantially increased.

Heretofor, the mechanisms used for actuating the cylinder grippers of conventional printing presses presented a major problem in the task of increasing the production of such presses. This was due to the fact that the cams used in these mechanisms had to be designed to operate efficiently when the impression cylinders were in their printing position as well as when they were tripped and as a result, a compromise cam was the only solution. In other words, instead of designing a cam for a specific purpose, it was necessary to compromise on the contour of the cam in order to attain the best results for two positions of the impression cylinder. At moderate speeds this arrangement was satisfactory, however, at higher speeds the noise and vibrations set up in the mechanism due to the compromise contour of the cam were prohibitive.

Furthermore, in the past these cams were not provided with adjusting means whereby machining tolerances etc. could be compensated for and while such discrepancies needed no consideration at average press speeds, they were magnified proportionately as the speed was increased, thereby presenting a definite limitation to any substantial increase in press production.

Several attempts have been made in the art to eliminate these dilficulties, such as for example, by providing double surface cams as shown in Patent #2,ll9,754, and others, but none of these methods accomplish the desired results, due to the lack of adjustability. Moreover, they are expensive to manufacture.

With my invention I provide adjustment whereby the gripper actuating cam may be set with relation to the path of its coacting follower to provide smooth, quiet operation at substantially higher operating speeds and whereby all tolerances may be compensated for. As a matter of fact, tests have proved that the speed of a conventional press can be increased 33% over its former maximum limit when my device is applied.

Therefore, it is a primary object of my invention to provide cylinder gripper actuating means which are economical to manufacture and efiicient in operation whereby the speeds of printing presses may be substantially increased.

Another object of this invention resides in the provision of adjusting means for a gripper actuating cam whereby the position of the leading and trailing edges of the cam may be positively set and maintained with relation to the path traveled by its associated follower.

A still further object is to provide means for preloading the cam against the impact of the cam follower.

Other objects and advantages will become apparent from the following description when read in conjunction with the accompanying drawings which depict a preferred embodiment of my invention. However, while I have chosen to illustrate my invention as applied to the second cylinder of a conventional two-color flat bed printing press, it is merely by way of example and I do not wish to be limited to any specific details. It will be understood that my invention may be applied with similar results to the transfer cylinder as well as the first impression cylinder and, as a matter of fact, to any mechanisms incorporating relatively fixed cams and moving cam followers.

In the drawings, Figure 1 is an elevational view of a two-color printing press embodying my invention;

Figure 2 is an enlarged view of that portion of the press showing the manner in which my device is mounted on the cylinder journal box; and

Figure 3 is a plan view of Figure 2.

In Figure 1 of the drawings, a conventional two-color flat bed press is shown having a feed board 10 over which the sheets to be printed are fed to the impression cylinder 11 to receive the first impression. They are then transferred by the transfer cylinder 12 to the second impression cylinder 13 for the second impression after which they are taken by the grippers 14 of the conveyor 15 and deposited on a delivery pile.

The impression cylinders 11 and 13 are journalled in bearing blocks 16 and 17 which are slidably mounted in side frame members 18 and are arranged to raise and lower their respective cylinders in the conventional manner during operation of the press. The type bed 19 which carries the form to be printed, is supported by the frame members 18 and reciprocates back and forth in timed relation to the cylinders which rotate constantly in a clockwise direction and complete two revolutions for each reciprocation of the bed. When the press is in operation, the cylinders 11 and 13 are down in their printing position during the impression stroke of the bed and are raised i. e. tripped away from the bed during its return i. e. non-printing stroke. This tripping action is accomplished sequentially so that the tripping of the second cylinder 13 is deferred until the sheet which was printed by the first cylinder 11 passes and receives an impression from the second cylinder. Because the mechanism for accomplishing this tripping action of the cylinders forms no part of this invention, it has not been shown in the drawings, but anyone acquainted with the art will readily understand the operation thereof.

As is more clearly illustrated in Figure 2, a series of gripper elements 21 are arranged in the impression cylinder 13 on a supporting shaft 22, the projecting end of which carries the lever 23. A cam follower 24 is rotatably mounted on lever 23 and is arranged to cooperate with a relatively fixed cam 26 to actuate the gripper elements 21 to release a sheet for delivery. It will be understood that opening of the grippers 21 is effected by the cam 26 and they are closed in a conventional manner by the pressure of springs, not shown. A pin 27 is also provided in the cylinder 13 to engage lever 23 to thereby limit its return movement and maintain follower 24 in a predetermined position when the grippers 21 are closed. It will also be understood that the first impression cylinder 11 and transfer cylinder 12 are also equipped and operated in the same manner but for the purpose of illustration I have restricted my description and drawings to the second impression cylinder.

During normal operation of the press, the cylinder grippers 21 are timed to release the sheets for delivery while the impression cylinder has just begun its raising movement and while still substantially in its down position. However, if the cylinder is tripped, the grippers 21 release the sheet to the delivery conveyor when the cylinder is in its raised or non-printing position. As a result, cam 26 must be arranged to actuate the gripper elements in both positions efiiciently and with a smooth action to avoid excessive noise and extreme vibrations at high speeds.

To accomplish the desired action, cam 26 is mounted to move up and down with the cylinder so that its aporoach 28 and trailing edge 29 always remain tangent .0 the path 30 traveled by the follower 24. As will be seen by referring to Figures 2 and 3, cam 26 is pivotally supported on the shaft 31 and is arranged to be slidable axially thereon. Shaft 31 is in turn fixed in the projecting walls 32 and 33 of the bracket 34 which is fixed securely to the bearing block 17 by means of the bolts 36. It will be apparent, therefore, that any movement of the cylinder 13 with the bearing blocks 17 will be transmitted to the cam 26 also.

Cam 26 is also provided with adjustable bolts 37 and 33, the rounded heads of which are arranged to engage the flat heads of associated bolts 39 and 41 respectively which are threaded into the bracket 34. As a result,

after the cam 26 is mounted in position on the shaft 31, ,the bolts 37 and 38 are adjusted to position the approach 28 and trailing edge 29 of the cam 26 exactly tangent to the path 30 of the follower 24 and any manufacturing tolerances inthe contour of, the. cam are readily compensated for. This adjustment is of..extreme. im-

portance. Whilethe discrepancies inthe contour of the cam; 26 .are comparatively minute andare. 'of no consequence when presses are operated at moderate speeds, any substantial increase insuch speeds. proportionately magnifies. these variations until they become i deciding Tfactors. in determining the maximum speed of a press.

.QConsequently, it is imperative that adjustments be made .available to compensate for them in order to achieve .smooth, vibrationless operation at any speed.

The adjustable bolts 37 and 38 also serve an additional purpose. They permit preloading of the cam 26 whereby the full impact of the follower 24, as it engages the cam -26, is. absorbed by the bracket 34 through the bolts 37 ..and'38. and the-forces are not exerted on the shaft 31. Moreover, all free play in the mechanism can be com- ;pletely eliminated.

It is, also essential that cam 26- be moved into and out of.the path, of the follower 24 for each alternate revolution of the cylinder .13 to prevent release of the sheets during/the impression' revolution of the cylinder. For "this purpose the hub of cam 26 is provided with a verti- -.ca1 slot .42 to receive the head 43 f the shaft 44 slidably mounted in the frame 18. The projecting end of the shaft -44 -is.provided with a-diagonally disposed slot on its bottom, side to receive the curved, angularly disposed ,blade 47 formed integral with lever- 48 pivotally mounted von the stud 49. Therefore, when lever 48 is oscillated ,about the axis of stud 49, the contour of its blade47 effects a relative axial reciprocating movement of the shaft 44 and due to its engagement with the slot 42 of .thecam' 26, said cam ismoved axially on its supporting shaft'31 into and out of the path of the follower 24.

.The vertical slot 42 also permits the cam 26 to raise and lower with the cylinder while maintaining its engagement with the shaft 44.

,Lever 48 receives its oscillating motion through the rod 51 which is eccentrically connected to the drive disc '52 which disc is driven by a convenient member of the ,pressdrive. mechanism and is timed to make one revolution every two revolutions of the cylinder 13.

-While I-have herein disclosed a preferred embodiment of my invention, I. do not wish to be limited to specific .details as modifications in the design and arrangement of ,parts may be made without departing from the spirit of .my invention orthe scope of the appended claims.

I claim:

1.-.In a printing press the combination comprising, a rotating sheet carrying cylinder having printing and tripped positions, gripper elements mounted on said cylin- .;der, mechanism for actuatingsaid elements including a cam follower mounted on said cylinder for movement in a circular path therewith, a relatively stationary cam segment pivotally mounted for adjustment about an axis transverse to the path of said follower and having its .followerengaging surfacearranged to engage said..fol-

lower at a predetermined rotative position of the cylinder, said cam being mountedfor bodily movement with the cylinder whereby it is effective for both positions of said cylinder, and adjustable means associated with said cam for effecting angular displacement thereof about its pivot axis to thereby position its follower engaging surface substantially. tangent to the path of said follower.

2. In a printing press the combination comprising a rotating sheet carrying cylinder, gripper elements mounted on said cylinder, mechanism for actuating said elements including a cam follower mounted on said cylinder for movement in a circular path therewith, a relatively stationary cam segment pivotally mounted about an axis transverse to the path of said follower and having its follower engaging surface arranged to engage said follower at a predetermined rotative position of the cylinder,

adjustable means associated with said cam and'having operation when adjusted to effect angular displacement thereof about its pivot axis to thereby move its follower engaging surface substantially tangent to the path of the follower and to thereafter maintain such position, and continuously oscillating means having operation to reciprocate said cam laterally, parallel to its pivot axis, into and out of the path of said follower in timed relation to the rotary motion of said cylinder.

3; In a printing press the combination comprising a rotating sheet carrying cylinder having movement between printing and tripped positions, gripper elements on said cylinder, mechanism for actuating said elements in both positions of said cylinder including a cam follower mountedon the cylinder for movement in a circular path upon rotation of the cylinder, a relatively stationary cam segment adapted to coact with said follower and having its follower engaging surface in the path thereof, said cam being pivotally mounted about an axis transverse to the path of said follower, adjustable screw means carried by the cam segment for adjusting its follower engaging surface relative to the path of said follower, mounting means for said cam segment associated with said cylinder whereby said cam segment is moved bodily in unison with the cylinder between said printing and tripped positions, and reciprocating means having operation to move said cam segment laterally, parallel to its pivot axis, into and out of the path of said follower for each alternate revolution of the cylinder, said reciprocating means having a slidable connect1on with said cam whereby it is effective to move said cam for both positions of said cylinder.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 684,224 .Grandy Oct. 8, 1901 1,326,798 Smith Dec. 30, 1919 1,645,469 Albert Oct. 11, 1927 2,468,254 Deloye Apr. 26, 1949

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