US3195457A - Printing plate lockup means - Google Patents

Description

July 20, 1965 H. J. LUEHRS 3,195,457

PRINTING PLATE LOCKUP MEANS Filed May 22, 1965 Fig.1

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1 I INVENTOR W 5 6 U-Luzmws I 1 M ATTORNEYJ [Illlln United States Patent l 3,195,457 PRENTING PLATE LGCKU? MEANS Hans J. Luehrs, Avondale, RL, assignor to The Cottrell Company, Westerly, ill, a corporation 01 Delaware Filed May 22, 1963, der. No. 282,407 Claims. (Q1. 101-378) This invention relates to improved means to lock printing plates to cylinders of hi h speed rotary printing presses. It is particularly concerned with the requirements of continuous high speed multicolor quality printing operations wherein accurate and quick positioning on, and safe and iirm securing of the plates to, their cylinders is most essential for fast and continuosly sustained printing.

An object of the invention is to provide means for initially locating and securely clamping all plates in register on their cylinder quickly, together v ith means to minutely adjust and square individual plates for final proof before the actual printing run begins.

Another object is to maintain plates securely in their locations on the plate cylinder through the use of automatic takeup means for plate tail clamps, or clips, to corn pensate for changes in the plates which may occur during continuous sustained high speed runs or" the press, thereby eliminating press stops for manual takeup of the plate lockup means.

Another object of the invention is to provide a structure in which there is a single actuating position for insertion of a tool for the manual actuation of each plate clip, said position being attainable within narrow margins and within the range of long and short plates, or narrow or wide plates, such as non-bleeds, without alteration of the structural assembly of the plate cylinder or change in the arrangement of individual plate lockup blocks.

Another object is to provide a printing plate cylinder with a rugged yet compact plate lockup said lockup having a minimum space requirement in the cylinder in order to retain maximum rigidity of the plate cylinder and its bearers, and comprisin individually adjustable opposed plate clamps in each lockup block.

A further object is to provide a means for clamping plates to a printing cylinder which means include multiple identical units carried by the plate cylinder and having their components so arranged that actuating means may be inserted between plates to align same on the cylinder Within a limited circumferential range, said actuating means being operatively connected with the plate clamping means through rotatable elements.

Another object is to provide a structure of the character described in which the plate cylinder locking mechanism includes elements tending to make certain of the adjusting means to be non-reversible in the absence of the voluntary application thereto of a reversing force.

A further object is to provide a structure of the character described in which the above and other objects may effectively be attained as will appear from the detailed specification which follows.

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

FIG. 1 represents an end View, partially broken away and partially in section, of a cylinder fragment illustrated in FIG. 2, showing one complete plate clamped thereto according to my invention and with portions of adjacent plates being shown in clamped position on the same cylinder; together with the key for individually actuating each plate engaging means.

FIG. 1 may also be described as part of a section taken on the line l1 of FIG. 2, looking in the direction of the arrows.

PEG. 2 represents a portion of the plate cylinder surface showing one complete plate and portions of other plates fidhdgi-E? Patented duly 20, 1965 clamped to said cylinder according to my invention, with said cylinder section and plate being partly broken away.

FIG. 3 represents a section taken on the line Illlll of FIG. 2 and looking in the direction of the arrows.

FIG. 4 represents a swung out section taken on the line IV-IV of 2 and looking in the direction of the arrows.

Referring to the accompanying drawings, the plate cylinder is denoted by 1 and the plate locking units, all of which are identical, are denoted generally by 2. Said units 2 are removably located in the longitudinal channels 18, across said cylinder by means of screws 29, to hold body 2:: in channel 13 said units 2 being shaped for concentricity with the cylinder surface.

A complete printing plate (MG. 1) is designated as 3, its leading end by i and its tail end by 5. Said plate 3 has its leading underside provided with scarfs, or recesses, 27, precisely located to be engaged by plate clips 6, it being understood that the tail end of plate 3 is also provided with under cuts 34 to receive the plate cli s 3.3.

The operation of the lockup units 2 will be described only with relation to plate 3, since all plates are similarly held at their leading and trailing recessed edges by similar plate clips 6 and 13 mounted in similar units 2. It will be understood that the locking units above referred to are applied only to the leading and trailing plate edges as the usual plate clips or steps 19 may be applied to the sides of the plates to prevent undesired longitudinal movement of the plate with respect to the cylinder (see FIG. 2), but which permit longitudinal adjustment of the plates.

in operation, the lead end of plate 3, as indicated by the arrow of FIG. 2 showing the direction of rotation of the cylinder has the leading edge plate scarfs or undercuts 27 engaged over the clips 6 and its tail scarfs 34 over the tail clips 33.3. As stated, means for manually adjusting the position of the plate 3 are provided to individually manipu late all plate clips and same include the hand tool or key ti illustrated in FIG. 1. Said tool end 311 is inserted through a desired available recess or keyway 7 to engage and turn, by said end 8a, a worm 9, and or, when desired, a worm 14. it will be observed that worm wheels 16), 15, also engage helical gears 11, 16, respectively which in turn engage racks 3d, 31 on the bottoms of clips 6 and 13. The lower portions of worms 9 noted above re provided with teeth 36, to engage ends 38 of spring loaded plungers 12, which will prevent creep of the plate, or plates, due to vibration normally encountered at high printing speeds.

The manual actuation of the plate clips 6 noted above may not be necessary as said leading clips 6 are normally retained in one position at all times. This position is dependent on the accuracy of location of the scaris 27 in the bottom of the plate 3 which engage said clips 6 with relation to the printed matter on the face of each plate. However, minute circumferential adjustment for exact color registration is further obtainable by the actuation through the manual means 8 and 8a previously described. As above noted, the action of spring loaded plungers 12 in engaging the indexed detents 35, of worm 9, securely maintains such measurable adjustments.

The actuation of the tail clips 13 is accomplished by manual means, key and 8a engaging the desired worm 14 which meshes with worm wheel 15. Helical gear 16 is slidably mounted on a splined shaft 41, which is integral with worm wheel 15. With the tail clips 13 disengaged, the initially spring-loaded helical gears 16 are firmly pressed against thrust washers 17.

Turning worms 14 in clockwise direction will move clips 13 towards the tail scarfs 34 in the plate 3, with the revolving helical gears 16 retaining contact with washer 17, until clips 13 firmly engage the scarfs 34. With this termination of the clip motion, further turning of the worm 14 will cause the helical gears 15 to climb along the helical teeth 31 of clips 13 while sliding on the splined shaft 41 of worm wheel 15, until springs 32are solidly compressed to terminate the sliding motion of gear 16 on 1 based at one end against gear 15 and at its other end against gear 16 which is slidably mounted on said spline 41. When worm 14 is turned by the tool end 8a, said worm 14 engages gear 15 to turn gear 16 whichis mounted on the splined shaftof gear 15. Gear 16 slides across rack teeth 31 on clip 13 to urge said rack circumferentially of cylinder 1 in unit 2 so that compression of spring 32 urges clip 13 into operative engagement with scarf 34. In order to accomplish this, the'ends of spring 32 are not attached either to gear 15 or gear 16, but are merely based thereagainst (see FIG. 3, left side).

In actual printing operation, plate 3 maybe moved with respect to clips 6 due to the rolling action and the squeeze between the plate and impression cylinders (not shown) and plate tail clips 13 thus serve as a takeup for any such motion. t

The angle of the teeth of helical gears 16 is selected so as tobe substantially irreversible in that the hooks 13 will take up plate stretch, but will not back up. Thus, the lead clips 6 being fixedly positioned, the tailjclips 13 provide a given amount of non-reversible takeup to compensate for such plate stretchwhile retaining the necessary forces on the clips 13 to securely hold the plates to the cylinder. 7

This non-reversible takeup action will thus allow long sustained press runs without the stops which have been heretofore required to manually take up on conventional plate lockup mechanisms at frequent intervals to prevent plates from flying off and causing smash-ups.

For the sidewise adjustment of the plates, conventional side stops, or adjustable clips 19 and 35 are provided to position and square the plates, these clips being slidably adjustable in suit-able longitudinal grooves, (not shown), in a manner well known in the art.

The lower end 8a of hexagonal key 8 is fitted to the internal hex 20, 21 of worms 9 or 14, with sufficient clearance to manipulate the key in any position within a cirworm thereon, a wheel engaged thereby, its shaft, a gear formed integral with said-last named shaft, a rack on said leading edge plate hook engaged by said gear and a spring pressed detent engaging said vertical rotative means to maintain same in a desired rotative position and means for actuating said trailing edge plate hooks for holding each plate to the cylinder under tension comprising a vertical rotative operating member including worm thereon,

a wheel engaged thereby, a splined shaft formed integral with said wheel, a gear slidably mounted for longitudinal movement on said splined shaft, a spring located between and in contact with said wheel and gear to assist and maintain the longitudinal movement of said. gear, racks on each trailing edge plate hook engaged by said gear and means for rotating the vertical rotative elements whereby arcuate movement in a desired direction is imparted to each plate hook through the said gear and rack engagement for tensioning each plate on'the cylinder.

2. A printing plate lockup means in combination with a printing press cylinder and at least one printing plate having recesses at its underside leading and trailing edges, comprising plate locking units, leading and trailing edge plate hooks in each unit engaging plate recesses for holding such plate edges to the cylinder, supporting means for the hooks for their movement into and out of contact with their plate recesses, actuating mechanism in each unit for moving each hook into and out of contact with its plate recess, said actuating mechanism for each leading edge hook comprising a vertical rotative element including a cu'rnferential range for adjacent-bleednon bleed or cen- V worm thereon, a worm wheel engaged thereby, its'shaft, a gear formed integral with said shaft, a rack on said leading edge plate hook engaged by said gear and a spring pressed detent engaging said vertical rotativemeans to maintain same in a desired rotative position and means for actuating each trailing edge platehook comprising a vertical rotative operating member including a worm thereon, a worm wheel engaged thereby, a shaft formed integral with'said wheel, a gear slidably mounted on said shaft, a rack on each trailing edge plate hook and resilient means for biasing said gear longitudinally into operative engagement with said rack whereby rotation of the vertical rotative element imparts arcuate movement toeach plate hook through the said rack and gear engagement for tensioning a plate on the cylinder. 1.

3. The'combination according to claim 2 including a V plurality of plates in which a plurality of plate locking It will be noted that a series of lockup units is normally used for each plate. will lock plate 3, the lead end of a second plate and the tail end of a third plate, and the pattern shown will be repeated around and across the entire cylinder in uniform repetition. Since the units are uniform in construction they are interchangeable and, asindicated above, each plate hook is individually adjustable by actuation of rotative means having automatic non-reversible elements co-' acting therewith to maintain the plates in their desired locations on the cylinder.

As illustrated in FIG. 2, six units units'are arranged in symmetric disposition on said cylinder and in which the means for rotating the vertical 1 rotative elements include access ports to said vertical ele- Since it is evident that variousv changes may be made I in the form, construction and arrangement of theseveral parts without departing from the spirit and scope of my invention, I do not intend to be limited to the particular embodiment herein shownand described except as set hook comprising a vertical rotative element-including a tive elements angled from the vertical to accommodate an angled introduction between plates of the means for rotating the vertical rotative elements. 7

5. A printing plate lockup .meansin combination with a printing press cylinder and at lea'stone printing plate having recesses at its undersideleading and trailing edges, comprising plate locking units, leading and trailing edge plate hooks in each unit engaging plate recesses for holding such plate edges to the cylinder, supporting means for the hooks for their movement into and out of contact with their plate recesses, actuating mechanism in each unit for moving each hook into and out of contact with its plate recess, said actuating mechanism for each leading edge hook comprising a vertical rotative element ineluding a worm thereon, a worm wheel engaged thereby, its shaft, a gear formed integral with said shaft, a rack on said leading edge plate hook engaged by said gear, and a spring pressed detent engaging said vertical rota- I I tive means to maintain same in a desired rotative position and means for actuating each trailing edge plate hook comprising a vertical rotative operating member including a Worm thereon, a worm Wheel engaged thereby, a shaft formed integral with said Wheel, a gear slidably mounted on said shaft and resilient means for biasing said gear longitudinally into operative engagement with said rack and automatically maintaining each plate tail clamp in arcuate adjustment comprising a spring surrounding said Wheel shaft and the worm Wheel and gear contacted by said spring whereby said gear is biased longitudinally and maintained in operative engagement by said spring to urge each trailing edge plate hook into engagement with its plate recess.

References (Iited by the Examiner UNITED STATES PATENTS ROBERT E. PULFREY, Primary Examiner.

EUGENE R. CAPOZIO, Examiner.

Claims (1)

1. A PRITNING PLATE LOCKUP MEANS IN COMBINATION WITH A PRINTING PRESS CYLINDER AND AT LEAST ONE PRINTING PLATER HAVING RECESSES AT ITS UNDERSIDE LEADING AND TRAILING EDGES, COMPRISING PLATE LOCKING UNITS, LEADING AND TRAILING EDGE PLATE HOOKS IN EACH UNIT ENGAGING PLATE RECESSES FOR HOLDING SUCH PLATE TO THE CYLINDER, SUPPORTING MEANS FOR THE HOOKS FOR THEIR MOVEMENT INTO AND OUT OF CONTACT WITH THEIR PLATE RECESSES, ACTUATING MECHANISM IN EACH UNIT FOR MOVING EACH HOOK INTO AND OUT OF CONTACT WITH ITS PLATE RECESS, SAID ACTUATING MECHANISM FOR EACH LEADING EDGE HOOK COMPRISING A VERTICAL ROTATIVE ELEMENT INCLUDING A WORM THEREON, A WHEEL ENGAGED THEREBY, ITS SHAFT, A GEAR FORMED INTEGRAL WITH SAID LAST NAMED SHAFT, A RACK ON SAID LEADING EDGE PLATE HOOK ENGAGED BY SAID GEAR AND A SPRING PRESSED DETENT ENGAGING SAID VERTICAL ROTATIVE MEANS TO MAINTAIN SAME IN A DESIRED ROTATIVE POSITION AND MEANS FOR ACTUATING SAID TRAILING EDGE PLATE HOOKS FOR HOLDING EACH PLATE TO THE CYLINDER UNDER TENSION COMPRISING A VERTICAL ROTATIVE OPERATING MEMBER INCLUDING WORM THEREON, A WHEEL ENGAGED THEREBY, A SPLINED SHAFT FORMED INTEGRAL WITH SAID WHEEL, A GEAR SLIDABLY MOUNTED FOR LONGITUDINAL MOVEMENT ON SAID SPLINED SHAFT, A SPRING LOCATED BETWEEN AND IN CONTACT WITH SAID WHEEL AND GEAR TO ASSIST AND MAINTAIN THE LONGITUDINAL MOVEMENT OF SAID GEAR, RACKS ON EACH TRAILING EDGES PLATE HOOK ENGAGED BY SAID GEAR AND MEANS FOR ROTATING THE VERTICAL ROTATIVE ELEMENTS WHEREBY ARCUATE MOVEMENT IN A DESIRED DIRECTION IS IMPARTED TO EACH PLATE HOOK THROUGH THE SAID GEAR AND RACK ENGAGEMENT FOR TENSIONING EACH PLATE ON THE CYLINDER.

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