US2928342A - Safety lock structure for internal lockup printing cylinders - Google Patents

Description

March 15, 1960 H. w. FAE'BER 2,923,342

SAFETY LOCK STRUCTURE FOR INTERNAILZ/LOCKUP PRINTING CYLINDERS Filed May z8, 1957 3 Sheets-Sheet 1 IN VEN TOR. HA RRY W. FAEBER his ATTORNEYS SAFETY LOCK STRUCTURE FOR INTERNAL LOCKUP PRINTING CYLINDERS Filed May 28, 1957 March 15, 1960 H. w. FAEBER 3 Sheets-Sheet 2 INVENTOR. F/6.2. HARRY W. FAEBER his ATTORNEYS March 15, 1960 H. w. FAEBER 2,928,342

SAFETY LOCK STRUCTURE FOR INTERNAL LOCKUP PRINTING CYLINDERS Filed May 28, 1957 v 3 Sheets-Sheet 3 llllll l l- MI I! -54 VA -11 I k: {lgj 5} f 11 5 if Z \1 3 I [I]! Z9 IN "I I. '1

Jill HI "KI I ll INVENTOR. HARRY W. FAEBER 37a gu 7 his ATTORNEYS SAFETY LOCK STRUCTURE FOR- INTERNAL LOCKUP PRINTING CYLINDERS Harry W. Faeber, Larchmont, N.Y., assignor to Time, Incorporated, New York, N.Y., a. corporation of New York Application May 28, 1957, Serial No. 662,051 9 Claims. (Cl, 101378) press have a tendency to loosen the lockingv action be tween the cylinder and the plate. Accordingly, to insure against the detachment of a plate from its supporting cylinder, it is important to provide means for locking the plate clamping mechanism.

The present invention provides an improved and effective means for lteking the plate clamping mechanism to insure that vibration will not accidentally loosen the locking action. In addition, in the event that the operator neglects to adjust the lock-up means of the. present invention in operative position prior to'starting up the I;

press, the present invention includes, as an additional safety feature, provision for automatically setting. the locking means tolocking position during the very first cycle'of rotation of the rotary cylinder.

For a complete understanding of the present invention, reference may be made to the detailed description which follows and to the accompanying drawings in which:

Figure l is a cross-sectional elevation view of a print ing couple wherein the plate cylinder .is' equipped with the locking mechanism of the present invention;

Figure' 2 is a fragmentary view ofthe circumference of the plate cylinder, that is to say, a view substantially along the line 22 of Figure 1 looking in-the direction of the arrows;

Figure 3 is a cross-sectional view taken along the-line 33 of Figure 2 looking in the direction of the arrows; t

Figure 4 is an enlarged view of one of the-components of the present invention; and

Figure 5 is a sectional view taken along the line 55 of Figure 3 looking in the direction of the arrows.

The present invention is shown as applicable to a plate clamping mechanism of the type described in United States Letters Patent, No. 2,621,590, ,of H. W. Faeber. Referring to Figure 1 of the drawings, a rotatable plate carrying cylinder and a rotatable impression cylinder is in tangential relationship therewith constitute a printing couple of a printing press. The plate carrying cylinder 10, formed of steel or any other'suitable material, is supported by a longitudinal shaft 12 which extends between side frames (not shown) of the press. The impression cylinder is similarly supported on a shaft which extends between the side frames of the machine. The cylinder 10 carries a plurality of circumferentially hired rates Patent mentioned patent.

* ice thereof for engaging companion recesses formed'in the.

are. atfixed by. screws 18 to the outer surface of the cylinder 10. a v

In some printing presses it is customary to'rnount sixteen printing plates to the plate cylinder), and each such printing plate is mounted to the plate cylinder by six clamping elements or, that is to say, by two groups of three clamping elements. The clip portions 14 of one of the two banks of clamping elements face in one direction and the clip portions of the other bank face in the opposite direction, To mount a. printing plate to the cylinder, the clamping elements of the two banks are moved in opposite directionsaway from each other into locking engagement with the mating recesses formed in the .printing'plate. To detach a printing plate, the clamping elements of the two banks are adjusted toward each other. As will be explained below, all of the clamping elements in a given bank are adjustable simultaneously by a single adjusting means. i

As shown in Figure 2, one end of the cylinder 10 accommodates'a plurality of pairs of rotatable concentric shafts 19, 20 arranged in a circular array within the cylinder and near the outer periphery thereof. Similarly, the other end of the cylinder 10 accommodates a pinrality of pairs of rotatable concentric shafts 21, 22 arranged in circular array within the cylinder and near the outer periphery'thereof. At both ends, the shafts 20 and 22 extend beyond the outer shafts. The shafts l9 and.20 are rotatable'independently of each other, as are the shafts 21, 22. Each of the shafts 19, 20, 21 and 22carries three pinions 23 thereon '(only one ofwhich is shown 'in the drawings), andeach pinion mesheswith rack teeth formed in the underside of one of the slides 15. Thus, the rotationof each of the shafts adjusts in unison three of the clamping elements 13.

At their extreme outboard ends, each of the shafts 19, 20; 21 and 22 carries a gear 25 which, as best shown in Figure. 3, meshes with a radially disposed worm 26.

The worm 26 is rotatably accommodated within one of thesegments 1tia.(see Figure l) which are carried at both ends of the cylinder 10. The outer end' of the worm 26 carries-a. cylindrical head 27 havingaIpo lygonal or non-circular keyhole 28' formed therein for receiving the end of an adjusting key (not-shown). The rotation of'the worm'26. imparts rotational movement to the gear 25 and to the corresponding shaft 19, 20,. 21 or 22 on which it is mounted to make possible the movement in unison of the threeclamping-elements-13 which are'adjustable thereby. =1 I The plate clamping-mechanism as thus far described is conventional and forms no part ofthe present invention. Fora more detailed description of this plate clamp-T I ing mechanism, reference -may be had to thexabove- Turning now to the present invention, the-adjusting heads27 are located around the periphery of the cyliri} der 10 in pairs, one for the adjustment of the respective outer-shaft Her 21 and one for the adjustmentofnthe respective inner shaft 20 or 22; The present invention provides a mechanism for locking both of these adjusting heads 27 in fixed position after they have beenadjusted to mount a printing plate to the cylinder 10. Ag-

adjustable plate clamping elements 13 (see Figure 2), j

.cordingly, as best shown in Figure 3, a circular recess 30 is, formed axially in the segment ltla such that both heads27 communicate with the recess, anda retatable cylinder 31 (see Figure 4) which houses a pair of spring The bodyof the cylinder 31 (see Figure 4) comprises three spaced apart journal portions 31a of circular crosssectlonto facilitate the rotational adjustment of the cylinder 31 within the circular recess 30.. ,Thecylinder 31 is cutaway intermediate the journal portions31a, and these intermediate portions 31b of the cylinder carry the spring urged locking elements 32 which are slidably accommodatedxin holes of substantially square cross-section.

The body of the slidable locking element 32 is hollow and open at the rear to receive'therein a compression spring .34 and a spring retaining rod 35. $1011 spring 34 acts against the head 35a of the rod, urging the locking element in the opposite direction or forwardly. The outer surface of thexhead 35a is preferably curved in substantially complementary fashion to the curvature of the wall which it engages, and the frictional contact between the head 35a and the wall helps to'hold the cylinder 31 in an adjusted position. Thus, the head 35a serves as a backing for the spring 34 whereby pressure is exerted on the locking element 32, urging, the tooth-like formation 32a into engagement with the ser rated outer surface of the head 27. The movement of the locking element 32 toward the outer surface of the head 27, however, is. limited by the engagement of a shoulder 32b formed by an outwardly disposed projecting flange at the rear end ofthe locking element with the 7 surface of the portion 31b within which the locking ele-' ment is accommodated. The shoulder 32b does not prevent the tooth-like formation 32a from engaging one of the grooves in the serrated head 27, but it does prevent interference between the tooth-likerformation and the surface which defines the wall of the-recess 30 when the cylinder is rotated within the recess 30 to move the tooth-like formation 32a to an inoperative position out of engagement with the head.27. Thus, for example, the cylinder 31 may be rotated approximately 90 to move the locking elements contained therein to a substantiallyvertical position withinrthe recess 30, thereby freeing both of the. worms 26 for rotation. As best shown in Figure 3, the extremeforward edge of the tooth-like formation 32a is curved in convex'ffashion, thereby providing an edge which is substantiallycomplementary to the wall defining the recess 30.

As best shown in Figure 4, the extreme outer end of the cylinder 31 is of slightly larger diameter than the main body of the cylinder 31, and this end of thecylinder is coupled to a manually operated control arm 39 by a splined connection (see Figure 1)..

When the cylinder 31 is in locking position, that is to say, the position shown in Figure 3 of the drawings,

the control arm 39 will be recessed within a slot 40 The compresformed within the circumference ofx the segment 10a. Seven of the control arms-'39. are shownin this position i in Figure. 1 of the drawings. In each case it is noted that the outer edge of the'arm' 39'extends substantially tangentially with respect to the outer periphery of the cylinder. One ofthe control ,arms 39 in Figure 1 is plate cylinder 10. v path to be engaged by the outer surface of the impression cylinder 11, as will be explainedmo're fully below, To

facilitate positionin'gthe control arm 39 in one or the other of these: positions, the control arm 39 is provided with a circular hub'portion 39a having a pair 'of spaced end of-a spring urged plunger 43 of square cross-section accommodated within a housing '44, The housings 44- 'are held by screws 44a to the sides of the segments 10a.

'apart notches 41, 42 which are engageable by the Wedge a The housing 44 contains a square'hole 45 which accommodates a compression spring 46 at the lower end thereof, urging the plunger into engagement with the hub 39a of the control arm 39 so as to engage one or the other of the notches 41, 42.

The operation of the locking mechanism of the present invention is apparentfrom the foregoing description. Withthe respective control arm 39 in the raised or release position, the cylinder 31 is adjusted to a, position at which the locking elements 32 carried thereby are vertically disposed within, the recess 30 or, in other words, out of engagement with the adjusting heads,27. Thus, with the locking elements 32 in this position, the pair of adjusting heads 27 which arereleased are free to be rotated by a key. As explained above, the rotation of the adjusting heads 27 transmits movement in unison to three of the plate clamping elements 13 through adjusting mechanism which includes the worm 26, the pinion 25, and the respective shaft 19, 20, 21 or 22. When a printing plate has been placed on the cylinder and plate clamping elements 13 adjusted to the plate clamping position, the control arm 39 is depressed, thus rotating the cylinder 31 to bring the tooth-like formations 32a of each of the locking elements 32 into engagement with the serrated outer peripheries of the adjusting heads 27. The lock ing elements 32 will, of course, prevent rotation of the wormdue to vibration effects during the operation of the press.

If by chance the tooth-like formation 32a is not aligned with respect to acorresponding groove of the respective adjusting head 27, this is of no concern,;because spring 34 will yieldand locking element32 will recede without damage to its own tooth or to theteeth on the periphery of head 27. The locking element will, nevertheless, be held into spring urged engagement with the head, so that in the event of any tendency of the plate clamps to loosen during operation of the, press, the maximum rotation permitted tetheworm 26 will be less than the distance between adjacent grooves formed on the outer periphery of the head 27, since the 'locking element 32 will engage the first such groove presented, to it.

In order to afiord a self-lockingfrictional engagement between the tooth 32d and the groove of the adjusting head 27, the flanks of each tooth (see Figure 5) are substantially planar surfaces which frictionally engage the surfaces definingthe groove inthe worm head 27 forming an included angle x. The magnitude of this angle is important because, if it is too large, the tendency of the worm head-27 to rotate due to vibration of ,the machine would cause the lockinggelementto rec'ede and ;To provide a spring 34 thusrelease the safety lock. strong enough to insure continued engagement under such condition would be impractical in view of the limited space available to accommodate the spring; In order to insurea locking action by the tooth 320, the angle defined "by the planar surface of the. flankloftthetooth and the surface of the groove which it frictionally engages must be less'tha'nthe angle corresponding to the coefficient of For example, when static friction between the surfaces. steel gearsare employed, and tassumlng that'the centerlines ofv the grooves of the worm head 27 are substantially radial to the axis of rotation of the worm, andwhen the number ofteeth is 34, the angle of the tooth flank haun not exceed about 3 /2. Asa safetyfeature, the present invention provides a safeguardflagairist the possibility that the operator will the release position, the

10,- Thus, if :the press is started while the control arm is in the raised or unlocked position, during the very first cycle of operation of theplate cylinder the arm 39 will strike the outer surface of the impression cylinder 11, moving the arm to locked position before the plate cylinder has accelerated sufiiciently to build up appreciable centrifugal force on the plate. In additio'n, the movement of the arm to locked position occurs before the plate is subjected to repeated pounding due to printing engagement with the impression cylinder, and thus before the effect of vibration has had an opportunity to exert any tendency to separate the plate from the plate cylinder, or to cause the plate holding mechanism to release the plate. a

The invention has been shown in a single preferred form and by way of example only, and obviously many variations and modifications may be made therein without departing from the spirit of the invention. The inventio'n, therefore, is not to be limited to any specified form or embodiment, except in so far as such limitations are set forth in the appended claims.

I claim:

1. A clamping mechanism for mounting a printing plate to a rotary cylinder of a printing press comprising a plate clamping element slidably mounted circumferentially of said cylinder, adjusting means for the plate clamping element carried by said rotary cylinder for moving said clamping element into locking and releasing positions, a rotatable control member for controlling the operation of said adjusting means, means forming an axial serration on said rotatable control memberya housing rotatably mounted in the cylinder adjacent the control member on an axis which is at an angle to the axis of rotation of the control member, a spring urged locking member to prevent interference between the tooth-like formation and the wall defining the circular recess in the cylinder when the housing is rotated from locked to released positions.

5. A clamping mechanism asset forth in claim 3 ineluding a plurality of notches formed in the rotatable element slidably mounted within the housing and movable into locking engagement with the adjusting means in one position of the housing, and manually engageable means whereby said housing may be rotated to a release position to disengage the locking element from the adjusting means.

2. A clamping mechanism for mounting a printing plate to a rotary cylinder of a printing press comprising a plate clamping element carried by said rotary cylinder, adjusting means carried by the rotary cylinder for moving the clamping element to locked and released positions, a housing rotatably mounted in the cylinder, a wall partly surrounding the housing, an opening in the wall adjacent a part of the adjusting means, a spring-urged locking element slidably mounted within the housing to engage and lock the adjusting means through said opening in one position of the housing, a control arm accessible from outside the rotary cylinder whereby the housing may be rotated to the released positio'n to disengage the locking element from the adjusting means, the-rotation of the housing to released position moving the locking element out of engagement with the adjusting means and into engagement with the wall, the control arm in open position projecting from the rotary cylinder, and means in the path of the control arm in open position to engage and restore to a locked position.

3. A clamping mechanism for mounting a printing plate to a rotary cylinder of a printing press comprising a plate clamping element carried by said rotary cylinder, adjusting means therefor to move said plate clamping element to locked and released positions, said adjusting means including a serrated rotatable member, a wall defining a circular recess in the cylinder adjacent said serrated rotatable member, an opening in said wall adjacent said adjusting means, a housing rotatably mounted in said circular recess, a spring urged locking element slidably mounted within the housing, said spring urged locking element being engageable with the serrated member in one adjusted position of the rotatable housing and being disengaged therefrom and engageable with the wall in another position of the rotatable housing, and a control arm accessible from the exterior of the rotatable cylinhousing and a spring urged detent engageable therewith to facilitate positioning the rotatable housing in locked or released positions. 7

6. A clamping mechanism as set forth in claim 3 wherein the rear of the locking element is hollow to accommodate therein a spring and a movable spring re taining memberwhich is engageable with the wall defining the circular recess.

7. A clamping mechanism for mounting a printing plate to a rotary cylinder of a printing press comprising a plate clamping means, adjusting means therefor to clamp and unclamp a printing plate to the rotary cylinder, means for locking and releasing said adjusting means, a member associated with said locking means movable into one position when the locking means is locked and into another position when the locking means is released, and means interposed in the path of travel of the movable member in the released position to engage and automatically move the member tolocking position during the rotation of the rotary cylinder.

8. A clamping mechanism for mounting a printing plate to a rotary cylinder of a printing press comprising a' plate clamping elementslidably mounted circumfcrentially of said cylinder, means carried by saidrotary cylinder for adjusting said clamping element, means for looking the clamping element in an adjusted position, a control handle for controlling the operation of said locking means, the control arm being recessed within the cylinder when in locked position and projecting outwardly from the cylinder when in released position, and means disposed in the path of travel-of the locking arm and engageable therewith to move the arm to locking positio during the rotation of the rotary cylinder.

9. A plate clamping mechanism for mounting a printing plate to a rotary cylinder of a printing press comprising a plate clamping element slidably mounted circumferentially of said cylinder, a radially disposed rotatable control element having longitudinal serrations thereon, means connecting said rotatable control element to the plate clamping element whereby the rotation of the control element adjusts the position of the plate clamping element, a housing rotatably mounted in the cylinder on an axis perpendicular to the axis of rotation of the control element, a spring-urged locking element slidably mounted within the housing, said locking element having a tooth-like portion at the end thereof which moves in a direction parallel with the longitudinal serrations of the control element when the housing is rotated so as to be movable into locking engagement with the control element in one position of the housing, and manually engageable means whereby said housing may be ro'tated independently of the control element to slidably disengage the tooth-like portion of the locking element from the longitudinal serrations of the rotatable control element to disengage the locking element from the control member.

References Cited in the file of this patent UNITED STATES PATENTS 2,075,559 Tollison Mar. 30, 1937 2,413,174 Crafts et al. Dec. 24, 1946 2,496,200 Crafts Ian. 31, 1950 2,621,590 Faeber Dec. 16, 1952 2,832,288 Harless Apr. 29, 1,958

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