US3043219A - Printing press machinery - Google Patents

Description

July 10, 1962 P DIETRICH PRINTING passs MACHINERY 2 Sheets-Sheet 1 Filed NOV. 21, 1958 3,M3,Zl9 Patented July 10, 1982 3,ti43,219 PRINTING PRESS MACHEQERY Paul Dietrich, Augsburg, Germany, assignor to Maschinenfahrik Augshurg-Nurnherg, A.G., Augsburg, Germany, a corporation of Germany Filed Nov. 21, 1958, Ser. No. 775,437 Claims priority, application Germany Dec. 7, 1957 3 Claims. (Cl. 101-373) This invention relates to printing presses and, more particularly, to apparatus and devices for clamping pn'nting plates, such as stereotype plates and the like, onto the plate cylinders of rotary printing presses by means of movable clamping hooks mounted in the plate cylinder for engaging recesses on the underside of the printing plate.

As is well known, in the mounting or clamping of printplates such as stereotype plates and the like onto the surface of the printing cylinders of rotary printing presses, it may be desired to have such plates held firmly onto the cylinder by clamping means wholly beneath or covered by the plates so that the outer printing surface of the plated cylinder is not interrupted by clamping devices, particularly in web-fed continuous printing presses, and also so that the plates are held firmly onto the plate cylinders against the inevitable play of centrifugal forces present with high speed printing presses and despite some flexing or stretching which may be inherent in the particular material from which the plates are made.

ulf it is attempted to accomplish the foregoing by an arrangement of movable hooks rotatably or pivotally mounted Within the plate cylinder on a shaft extending across the cylinder, some difficulties may be experienced in obtaining a firm and uniform clamping pressure of hooks clear across the cylinder due to torsional effects of the shaft on which the hooks are pivotally mounted, and particularly in wider presses. Similarly, particularly with high speed presses of substantial width the considerable weight of type-metal stereotype plates may, indeed, accentuate such non-uniformity of clamping under the high centrifugal forces to which such plates are subject in use, with substantial damage, or at least down time, resulting from such loosening. Similarly, it it is attempted to correct the foregoing situation by mounting the several clamping means on a rotatable shaft and angularly or helically spaced to compensate torsional variations in the angular displacement of the shaft upon rotation thereof from only one end thereof in moving the several hooks into clamping position, additional difficulties may be encountered in connection with, for example, predetermining exactly the required angular displacement of the hooks for ultimate uniform clamping pressure and/or with regard to substantial dimensional variations and non-uniformity among, particularly, stereotype plates.

According to this invention, however, a firm and uniform clamping of printing plates such as sterotype plates and the like, is achieved on the plate cylinder of high speed rotary printing presses by providing, mounted in the plate cylinder, a plurality of independently pivotally mounted swingable hooks for engaging a recess on the underside of the plate adjacent one axial edge thereof with the hooks being forced into clamping position 'by the cam action of a rotating member mounted separately from the pivotal mounting of the hooks and independent of torsion movement at the hook pivots for positive and uniform engagement across the axial extent with the plate cylinder substantially independent of torsional deflections. Similarly, according to this invention, such positive clamping of the opposite axial edge of the printing plate is cooperatively arranged by having corresponding oppositely directed movable hooks independently mounted for pivotal movement substantially free of torsional variations of a common shaft and either resiliently urged into firm engagement o-r similarly cammed into clamping position.

One object of this invention is to provide means for clamping opposite axial edges of printing plates and the like to the plate cylinder of a rotary printing press with a plurality of clamping hooks in the plate cylinder engaged with the underside of the printing plate whereby a uniformity of clamping pressure across the cylinder is achieved independent of and notwithstanding torsional deflections which might be experienced if the plurality of hooks were rotatably mounted on a common shaft extending the length of the printing cylinder.

Another object of this invention is to provide plate clamping means of the character described for rotary printing presses in which a plurality of plate clamping hooks are arranged separately and independently ivotally mounted across the plate cylinder for swinging motion with respect to the printing plate to be clamped, and providing a rotary camming mechanism substantially independent of the pivotal mountings of the hooks for urging the hooks into clamping engagement independently of torsion effects on the pivotal mountings thereof.

A further object of this invention is to provide, in rotary printing press plate cylinders of the character described, clamping means for engaging opposite axial edges of printing plates including a plurality of clamping hook means pivotally mounted in the cylinder for engagement with one axial edge of the printing plate and a similar plurality of clamping hooks for engaging the opposite axial edge thereof, with camming means for urging the clamping hooks into clamping engagement and mounted in the plate cylinder separately from the clamping hooks and independently of torsional non-uniformity or deflections to which the hooks are subject.

A still further object of the invention is to provide, in rotaryprinting press plate cylinders of the character described, clamping means for engaging opposite axial edges of printing plates including a plurality of clamping hook means pivotally mounted in the cylinder for engagement with one axial edge of the printing plate and a similar plurality of clamping hooks for engaging the opposite axial edge thereof,.with camming means for urging the clamping hooks into clamping engagement and mounted in the plate cylinder separately from the clamping hooks and independently of torsional non-uniformity or deflections to Which the hooks are subject for clamping one axial edge of the plate, and resilient means for urging the hooks clamping the opposite edge of the plate into clamping position for firm but resilient cooperative clamping engagement with the first set of hooks as adjusting by the cam means operative thereon.

Other objects and advantages of this invention will be apparent from the following description, the accompanying drawings, and the appended claims.

In the drawings- FIG. 1 is a transverse section through a plate cylinder embodying this invention and taken along the line 1-1 of FIG. 3;

FIG. 2 is a fragmentary detail view on a larger scale of a portion of the embodiment of FIG. 1;

FIG. 3 is an axial partial section of a plate cylinder embodying this invention and taken along the line III-III of FIG. 1;

FIG. 4 is a fragmentary view on a larger scale of a detail of a further embodiment of one aspect of this invention; and i v FIG. 5 is a partial transverse section along the line V--V of FIG. 3.

Referring to the drawings, in which like characters of reference refer to like parts throughout the several views against hooks 15.

,3 thereof, a plate cylinder of a rotary printing press is indicated at as having two stereotype plates 11 and 12 clamped around the surface thereof. Each of the plates 11 and 12 include, adjacent opposite axial edges thereof, a recess or clamping notch 13 for the engagement therein of a plurality of clamping hooks 14, forengaging one axial edge of the plates 11 and 12, and an additional plurality of hooks for engaging the opposite axial edge of plates 11 and 12. Y

1 As indicated, particularly in FIGS. 1 and 3, although there are a number of hooks 1 and 15 spaced at various points along the axial extent of cylinder 10, each of the hooks 14 and 15 is separately or independently mounted within cylinder 10 for independent pivotal movement into and out of clamping engagement with the notches or recesses 13 adjacent opposite axial edges of the plates 11 and 12. In the illustrated embodiment, such independent pivotal mounting includes a more or less cylindrical bearing portion on each ofthe hooks 14- and 15, having an axis generally parallel to the axis of cylinder 10, and supported generally in cylindrical axial recesses 21 in cylinder 10. As will be noted, particularly from the enlarged showing of FIG. 2, the foregoing arrangement permits of the swinging or pivotal movement of clamping 7 books 14 and 15 toward'and away from clamping engageor out of clamping positions were achieved inerely by rotation of such common shaft from but one end thereof. With the aforementioned independent pivotal mounting of hooks 14, movement thereof into clamping position is satisfactorily accomplished, according to this invention, by a cam or clamping spindle arrangement illustrated at 25 as being generally a rod or rotatable shaft extending axially of the cylinder long an axis generally parallel thereto and having a fiat or cam surface 26 thereon. The axis of shaft 25 is displaced from the axis of pivotal mounting 20 of hooks 14 such that, when shaft 25 is ro- 1 tated so as to present flat 26 to hooks 14, the hooks may relax from clamping position, but, when shaft 25 is otherwise rotated to a different angular position, hooks 14 are cammed or forced into clamping position in recess 13 of plates 11 or 12 as illustrated by the left-hand hook 14 in FIG. 1 andthe right-handbook 14 in FIG. 2, and satisfactory results 'are achieved by mounting shaft 25 in a generally cylindrical bearing recess 27 in cylinder 10.

' As previously-noted, the axial edge ofeither plate 11 or 12 opposite to the edge clamped by hooks 14 is clampedby the hooks '15, but preferably in a resilient, although firmly resistant, manner. Thus. whereas the v camor shaft 25 for hooks 14 is positively rotated into clamping position by operating means (not shown) at one end of the plate cylinder and accessible to an oper- A ing force of hooks 14 may act. As will be understood, of course, the length of lever arm and the strength of compression spring 36 are correlated to provide adequate clamping pressure. In this connection, and, of course, depending upon the size and speed of the printing press and plates, a single lever arm 35 and spring 36 may be arranged to control the clamping pressure of a plurality of clamping hooks 15 through a cross-bar 37 (as illustrated by the top four books 15in FIG. 3 or the next lower pair of hooks in FIG. 3) or, in certain cases, satisfactory results are achieved by having an individual lever arm 35 and spring 36 for each hook 15, as illustrated in the bottom two hooks 15 of FIG. 3. Also, satisfactory results are achieved by providing a more or less radial bore 38 in cylinder 10 for accommodating spring'36 with an adjustable screw 39 or the like, for adjusting the tension or force of spring 36 and accessible from the outer surface of cylinder lti when such surface is not covered by one of the plates 11 or 12. Similarly, as illustrated in FIG. 4, in certain cases satisfactory results are achieved by having a compression springdil mounted in a recess 41, preferably around a 'slidable holding pin 4-2 acting directly on each of the books 15 for resiliently yet firmly urging hook 15 into'clamping position, and particularly in places where the size and speed is such as not to require the extra clamping force obtainable with the eccentric lever arm arrangement 35.

With such resilient clamping of the, hooks 15, as will be understood, it is preferred to provide a spring-loaded locking pin arrangement, as illustrated at 45 for locking shaft 25 into .a particular angular position to which it is set by the aforementioned operating means therefor, and, the several hooks 14 are also preferably provided with a fairly soft compression spring 46 for urging the hooks into open or disengaged position (as indicated by the right-hand hook 14 in FIG. 1) upon relaxation or rotation of the cam shaft 25 into open or non-clamping position.

As illustrative of a satisfactory'and simple means for assembling and fabricating a plate cylinder 10 embodying this'invention may be noted that the axial or longitudinal pressure strip or member 50 running along plate cylinder lu and being afiixed thereto by a plurality of bolts 51.

Preferably the outer circumferential dimension of member 50 is sufficientto extend beneath the axial edges of two adjacent printing plates 11 and 12, for forming a firm clamping surface for cooperation with clamping hooks 14 and 15, and preferably includes :circumferentially Wider portions forming seating surfaces 52 axially between adjacent hooks 14 and 15 for direct bearing engagement with the main core of cylinder 16, as illustrated particularly in FIG. 5. The radially inner surface of member 59 may satisfactorily include a curved recess for cooperation with a corresponding curved recess in cylinder 19 to form the cylindrical bearing surfaces 21 in which hooks 14 and 15 are individualy mounted for pivotal movement as noted.

As will be apparent from the foregoing illustrative explana tion of a structure embodying this invention, positive clamping of one axial edge ofprinting' plates 11 or 12'to plate cylin'derlti is achieved by the positive urging ator from the outside .thereof, a'similar shaft 28 with a. 7

similar flat or cam surface 29 rotatably mounted in a cylindrical recess or bearing surface 30 is provided for automatically resilient rotation and camming .action .As illustrative of one satisfactory manner of achieving this resilient cooperative clamping pressure may be noted. the provision of a plurality of -lever arms 35 mounted on shaft 28 at various points strong yet resilient force against which the positive clampof pivoted hooks 14 into recesses 13 under the action of cammed shaft 25 so that the plate, through recess 13 therein, is circumferentiallyfand radially held firmly in position by hook 14 acting against pressure strip or member 50. At the same time, although clamping hooks 15 acaamo as may be incurred in use and particularly in very high speed or long runs of the printing press. Accordingly, a

simple and economical arrangement is provided, having simplicity and easy access for adjustment, whereby firm and uniform clamping of the printing plates is provided across the axial extent of the plate cylinder, free of torsional deflections or non-uniformity due to rotary elements thereof and/or actual radial moments of clamping pressure, and yet resiliently arranged to maintain a uniform and firm clamping pressure despite Variations of the plate in use.

While the methods and forms of apparatus herein described constitute a preferred embodiment of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

I claim:

1. In a device for clamping stereotype printing plates and the like onto the plate cylinder of a rotary printing press, the combination which comprises a set of clamping hooks for clamping engagement with each of the opposite axial edges of said plates, means for separately and individually pivotally mounting said clamping hooks in said plate cylinder for arcuate swinging movement of said hooks selectively into and out of clamping engagement with said plates, said pivotal mounting means supporting each of said hooks substantially continuously throughout the axial extent thereof adjacent the axis of said pivotal mounting, rotatable cam means for swinging each of said hooks in each of said sets of hooks into said clamping position upon rotation of said cam means, spring means for rotating said cam means for one of said sets of hooks for resiliently urging said hooks into said clamping position along one axial edge of said plate, and operative means accessible from an end of said cylinder for rotating said cam means for the set of hooks at the opposite edge of said plate for swinging said hooks into and out of said clamping position.

2. In a device for clamping stereotype printing plates onto the plate cylinder of a rotary printing press, the combination which comprises a set of separate clamping hooks for clamping engagement with each of the opposite axial edges of said printing plate, means for separately and individually pivotally mounting said clamping hooks in said plate cylinder for arcuate swinging movement of said hooks selectively into and out of clamping engagement with said plate, means for resiliently urging one of said sets of hooks at one edge of said plate each into said clamping position, a rotatable longitudinal shaft in said cylinder and extending therealong adjacent the set of hooks at the opposite edge of said plate but separately from said pivotal mounting thereof for swinging each of said hooks into clamping position upon rotation of said shaft, said shaft having cam surfaces for urging said hooks into said clamping position in one angular rotational position of said shaft and being relieved sufficiently in another angular rotational position for permitting retracting said hooks substantially completely into said cylincler to facilitate removal of said printing plate therefrom, each of said separate hooks engaged by said shaft including cylindrical bearing surfaces for said pivotal mounting of said hooks along the radially inner edges thereof substantially throughout the axial extent thereof, said separate hooks directly engaging said cam surfaces on said longitudinal shaft substantially throughout the axial extent of each of said hooks, and said means for pivotally mounting said clamping hooks including a fixed semi-cylindrical groove extending axially in said cylinder forming a rigid bearing support for receiving and supporting said cylindrical bearing surfaces on a plurality of said hooks engaged by said shaft, and a removable rigid axial member for cooperating with said groove to engage said cylindrical bearing surfaceson said hooks and to complete said pivotal mounting and support thereof.

3. A stereotype plate clamping device as recited in claim 2 in which the axis of rotation of said longitudinal shaft having said cam surfaces thereon is positioned in said cylinder radially outwardly of the axis of said pivotal mounting of said hooks whereby said direct engagement of said cam surfaces with said hooks is spaced along said hooks radially outwardly of the axis of said pivotal mounting thereof, each of said hooks having a substantially uniform cross section throughout the entire axial extent thereof, and which device also includes operating means accessible from one end of said cylinder for rotating said longitudinal shaft and said cam surfaces thereon.

References Cited in the file of this patent UNITED STATES PATENTS 2,047,357 Crafts July 14, 1936 2,180,732 Durham Nov. 21, 1939 2,236,230 Worthington Mar. 25, 1941 2,413,174 Crafts et a1 Dec. 24, 1946 2,689,411 Huck Sept. 21, 1954 2,708,875 Harless May 24, 1955 2,818,806 Harless Jan. 7, 1958 2,832,288 Harless Apr. 29, 1958 2,900,903 Chase Aug. 25, 1959 FOREIGN PATENTS 583,771 Great Britain Dec. 30, 1946

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