US3156184A

US3156184A - Plate clamp

Info

Publication number: US3156184A
Application number: US174490A
Authority: US
Inventors: Darl T Shank
Original assignee: Harris Intertype Corp
Current assignee: Harris Graphics Corp
Priority date: 1962-02-20
Filing date: 1962-02-20
Publication date: 1964-11-10
Anticipated expiration: 1981-11-10

Description

D. T. SHANK PLATE CLAMP Nov. 10, 1964 2 Sheets-Sheet 1 Filed Feb. 2G, 1962 INVENTOR.

DARL T. SHANK ATToFNEYs Nov. 10, 1964 D. T. SHAN K PLATE CLAMP Filed Feb. 20, 1962 Fna-1o 35 50 60 lo z. es 62 67 FIG-n 35 50 2 Sheets-Sheet 2 INV EN TOR.

DARL T. SHANK ATTORNEYS United States Patent O `i ce 3,156,184 Y PLATE CLAMP Darl T. Shank, Dayton, Ohio, assigner to Harris-Intertype Corporation, Cleveland, Ohio, a corporation of Delaware Filed Feb. 20, 1962, Ser. No. 174,490 7 Claims. (Cl. lill-415.1)

The present invention relates to plate clamps for coating or printing machines, and particularly to a novel plate clamp construction which Will rapidly connect the trailing edge of a flexible plate to a cylinder and then tension the plate to hold it immediately adjacent the cylinder.

The invention is concerned primarily, although not exclusively, with apparatus utilized to secure a flexible plate to a cylinder, as for instance, an embossed plate for use in paper coating machines or a lithographie printing plate used in a printing press. In such apparatus it is often desired and many times required that the trailing edge of the flexible plate be tightly clamped to the cylinder in such a manner that there will be no relative movement therebetween. In order to attain this closeness, the plate must be tensioned and it is desirable to apply this tension in conjunction with the clamping apparatus. Of particular importance is the requirement that such apparatus be simple in design for maximum dependability and that it be easily actuated preferably by simple manual movements so that the plate can be properly secured to the cylinder with a minimum of time and effort. j

Accordingly, a particular object of this invention is to provide apparatus for securely clamping a flexible plate to a cylinder including a clamp which will positively lock the iiexible plate to the cylinder in response to a manual actuation while being easily and quickly releasable.

Another object of the invention is to provide apparatus for securely clamping a llexible member to a cylinder and applying tensioning to the plate to hold the same close to the cylinder which requires only simple manual movements to clamp and tension the plate, as well as release this tension and unclamp the plate.

A further object of the invention is to provide a clamping and tensioning apparatus for securely holding the trailing edge of a fiexibie plate on a cylinder wherein the apparatus is capable of being sequentially operated 3,156,184 Patented- Nov. 10, 1964 FIG. 7 is a sectional View similar to FIG. 3 but illustrating the cam and clamp means in an alternate position;

FIG. 8 is a sectional view essentially along the line 3-8 of FIG. 2;

FIG. 9 is a sectional view similar to that of FIG. 7 and illustrating the cam means in an alternate position;

FIG. l0 is a sectional View essentially along the line lil-lil of FIG. 2; and

FlG. l1 is a sectional view essentially along the line 11-11 of FIG. 2.

Referring to the drawings which illustrate a preferred embodiment of the invention, FIG. 1 shows diagrammatically a cylinder 1t) similar to those utilized on a coating machine, printing press or the like and having an embossing or printing plate 11 of a flexible material secured thereto. The leading edge 13 of the plate 11 is rigidly clamped between the members 15-16 by the bolts 17 after the plate 11 has been manually aligned therebetween. The trailing edge 18 of the plate 11 is releasably clamped in a novel plate clamp 20 which, in addition to clamping the trailing edge 18, tensions the plate properly on the cylinder 1i).

As shown in FIGS. 2 and 3 the plate clamp 20 includes the elongated supporting bar or base plate 21 which is mounted for certain relative movements in the recess 23 cut in the cylinder 10, but held against movement in a radial direction with respect to the cylinder 10 by end pieces 2.5 which are secured to cylinder 11 at each end of the base plate 21 by the bolts 27 and which have a flange 23 which extends over the end of the plate 21. A bore or recess 30 in the base plate 21 holds the spring 31 which rides flange 23 to hold the plate against any signiicant radial movement with respect to the cylinder 10 while permitting it to move within limits toward ,and away from the shoulder 32 of recess 23. In addition, limited axial movement of the plate 21 with respect to the cylinder 10 to iirst clamp the plate and then apply tension thereto or to untension the plate and then unclamp the same which apparatus is simple in design for ultimate dependability and ease and speed of operation.

FIG. l is a schematic end view of a cylinder utilizing the invention to clamp a plate thereon;

FiG. 2 is a fragmentary plan view of a clamp built according to the invention;

FIG. 3 is a sectional view taken essentially along the line 3-3 of FIG.y 2;

FIG. 4 is a fragmentary illustration, partially in section, showing an end clamp; Y

FIG. 5 is a similar sectional view taken essentially along the line 5--5 of FiG. 2;

, FIG. 6 is a sectional view similar to that of FlG. 4 butY showing. the cams in an alternate positiomjis accomplished and controlled by a screw member" 33 threaded through each end clamp 25 for engagement with the end of the plate 21. By retracting the screw 33 on one end of the plate 2.1 and tightening the screw on the other end the plate 21 can be moved axially on the cylinder 1b.

The apparatus utilized to clamp the edge 13 of the flexible plate 11 to the support plate 21, as shown in FIG. 3, includes an elongated clamp bar 35 which is substantially coextensive with the plate 21, save the clearance provided for the end clamps 25, A plurality of spaced pivot bolts 36 having semi-spherical heads 37 are inserted through the openings 39 in the clamp bar 35 and screwed into the threaded bores 40 of the support plate 21 thereby pivotally securing this clamp bar 3S on plate 21. A

The surfaces of the openings 3g and the spherical heads 37 are similarly shaped so that the clamp bar 35 will pivot about the heads 37 between the positions shown in FIGS. 3 and 7. The bolts 36 can be screwed into or out of the plate Z1 to permit the effective pivot point of bar 35 to be raised or lowered to compensate for the varying thickness of the plate 11, so that the clamping surface 41 will t iiat against the plate 11. After the proper adjustments are made each of the 'bolts 36 isV locked into position by a pin 42 which is forced thereagainst by rotating theV threaded plug i3 in the similarly threaded bore 44 of the 3 support plate 21. The clamping surface 41 which engages the edge 18 of plate 11 is knurled so that it is held against slippage, and the opposite side of the clamp bar 35 includes a cam follower portion 47 engaging the cam bar 56 which is coextensive with clamp bar 35.

A coil spring 51 is placed in each of the longitudinally spaced recesses 52, see FIGS. 2 and 5, in such a manner that the springs tend to move the clamp bar 35 about the pivot bolt 36 to relieve any pressure exerted by the surface 41 on the edge 13 of plate 1l. On the other hand, the clamp bar 35 may be pivoted against the bias of these springs 51 to a clamping position by the cam bar 5t) which is rotatably journaled in bearings 53 and rides in a groove 54 formed in the support plate 21. FIG. 7 illustrates the cam bar t) moved to an inactive position wherein the spring 51 has rotated the clamp bar 35 in a clockwise direction to release the clamping pressure on the edge 1S of the flexible plate l1. Further counterclockwise rotation of cam bar 5@ from this position is prohibited by the ear 55 formed thereon.

A cam actuator block 56 utilized to rotate cam bar 5G is rigidly secured thereto by the pins 57 at a position midway between the ends of the assembly and both the clamp bar 35 and the support plate 21 are cut out at S (see FIGS. 2 and 8) in order that this block 56 may rotate freely and to provide surfaces on which the bearings 53 are mounted by the bolts 59.

The apparatus for tensioning the plate 11 on the cylinder once it has been clamped to the support bar 21 includes a spring means shown in FIG. 10 and a manually actuated means shown in FIG. 1l both of which move 4the support plate 2l away from shoulders 32 (to the right as viewed in FIG. l). The spring means include a coil spring 6) interposed between the disk 62 mounted in the recess d3 of the support plate 2l and the shoulder 32 for urging the plate Z1 to the right thereby tensioning the tiexible plate 11 when the latter is clamped thereto. The force exerted by spring 60 can be varied within certain limits by the threaded plug 65 which engages the similarly threaded bore 67 in the plate 21. On the other hand, each of the manually actuated tensioning means shown in FIG. l1 includes a manually adjustable pin 7d slidably mounted in a bore 71 of the plate 21. Pin 70 is forced against the shoulder 32 of the cylinder 1t? by rotation of the threaded bolt 73 which engages similarly threaded bore 74. The bolt 73 has an enlarged head 75 with radial openings 77 therein for inser-tion of a tool or bar to facilitate the rotation thereof and a lock nut 78 is provided for locking the bolt 73 in position. It should be appreciated that this tensioning means is of the positive type whereas the spring tensioning means of FIG. l() merely provides tensioning in an amount equal to the biasing effect of the springs 63.

A tensioning cam Si) is rigidly held on the cam bar 5t) on either side or" the actuator block 56 by pins 31 and acts against the stationary blocks 82 secured to cylinder 1G by the bolts 83. The cam 8G has an annular extension 84-85 and formed integrally therewith on either side thereof. As shown, one of these extensions 84 accommodates the pin 81 to secure the cam to the bar Sti while the other extension 85 engages the bearing 53 to support both the cam 3l? and cam bar 5d. As shown in FG. 5 rotation of the tensioning cam 80 effects movement of the support plate 21 toward the shoulder 32 to a position wherein this tension is released, that is, to an active position wherein the plate 2l is moved toward the left against the bias of the spring @il thereby relieving the tension on the plate 1l. Naturally, if the positive tensioning means of FIG. 1l is engaged it must be retracte before the cam 8? can move the support plate 21| to the left for relieving this tension. FG. 6 shows the tensioning cam 80 rotated to an inactive position wherein it no longer engages the block 82 and the spring 6d of the positive tensioning means of FlG. ll are free to apply tension to the plate 1i. Hence, Vit should Vbe apparent L that the primary purpose of the tensioning cam is to relieve the tensioning being applied to the plate 11 by the spring 64B and to move the plate 21 toward the shoulder 32..

Since the tensioning cam 80 and the cam bar 50 are rigidly interconnected and hence rotate together their relative angular position must be precisely established before they are interconnected to insure proper operation of the invention. This precise positioning permits a highly desirable sequence of operations to take place, and can best be explained by setting forth the sequence of operations. Starting with the cam bar 5t) in the position shown in FIG. 7 wherein spring 60 pivots the clamp bar 35 to its released position, clockwise rotation of cam bar Sil will clamp the edge 17 of the plate 11 to the support plate 21 thereby pivoting the clamp bar 35 against the bias of spring 50 to the position shown in FIG, 5, wherein the plate 11 is securely clamped to the plate 21. Further clockwise rotation of the cam bar Sil then moves the tensioning cam 80 from the active position shown in FIG. 5 to the inactive position shown in FIG. 6 wherein the cam @il is spaced from the block 82 and tensioning is applied to the plate 11 by the spring d@ or the positive means shown in FIG. 11. The tensioning and clamping of the plate 11 is relieved by rotating the bar 3S in a counterclockwise direction from the position shown in FIG. 5. It should be apparent from the foregoing that the cam bar 50 and the tension cam 80 are so shaped that tensioning will never be applied unless the plate 11 is first clamped to the support plate 21. The clamp bar 35 cannot release the plate 11 unless the tension applied thereto has been previously relieved.

Rotation of the cam bar 50 is accomplished by inserting an appropriate tool 87 into one of the two angularly spaced holes 88 and 89 (FIGS. 8-9) in the block 56 to thereby rotate the same. These holes are angularly spaced so that when the system is mounted in its operative environment a tool inserted in the hole 88 will rotate the block 56 only a sufficient amount to rotate the cam bar 50 between the positions shown in FIGS. 5 and 7 whereas when the tool is withdrawn from the hole 88 and inserted in the other hole S7 the cam bar S0 can be rotated between the positions shown in FIGS. 5 and 6. The limits on the movement of the tool are imposed by the clearance between the tool and the machinery associated with the plate clamp. The dual set of holes therefore conveniently limit the movement of tool 87 to thereby separate the clamping and tensioning phases of the mechanism. While this is the preferred manner of applying rotation to the cam bar 50 and the tension cam Sil, it is within the contemplation of the invention that other and structurally different expedients can be utilized. For example, the cam 50 could be extended past the end clamp 25 and a suitable configuration formed on this end for gripping with an appropriate tool.

While the invention has been shown and described in connection with a cylinder used in coating machinery or a printing press, it should be understood that it may nd use in other environment without departing from the scope of the invention. For example, the novel plate clamp could be utilized to clamp and tension flexible or semiiexible members on a fiat surface. The amount of tensioning can be varied by merely altering the apparatus to provide for more or less movement of the plate 21 toward and away from the shoulder 32 as well as by changing the bias of spring.

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

What is claimed is:

l. A plate clamp for releasably securing and tensioning a flexible member on a mounting surface, comprising an elongated support plate mounted for limited movement with respect to said surface, clamping means mounted on said plate and movable to a lirst position for cooperation with said plate in clamping one end of the member to said plate and also movable to a second position releasing the one end of the member, first spring means urging said clamping means forward to said second position, a first cam means operable on said clamping means and movable between an active position holding said clamping means in said first position and an inactive position wherein said first spring means moves said clamping means to its said second position, second spring means urging said plate toward a tensioning position for applying tension to the member, second cam means operable on said plate and movable to one position to move said plate against said second spring means for relieving tension in the member, said second cam means also being movable to an opposite position causing said second spring means to tension the member, and singular cam actuator means operable to move said first cam means to its said active position and then to move said second cam means to its said opposite position.

2. A plate clamp for releasably securing and tensioning a flexible member on a mounting surface, comprising an elongated support plate mounted for limited movement with respect to said surface, clamping means mounted on said plate and movable to a first position for cooperation with said plate in clamping one end of the member to said plate and also movable to a second position releasing the one end of the member, rst spring means urging said clamping means forward to said second position, a first cam means operable on said clamping means and movable between an active position holding said clamping means in said first position and an inactive position wherein said first spring means moves said clamping means to its said second position, second spring means urging said plate toward a tensioning position for applying tension to said member, second cam means operable on said plate and movable to one position to move said plate against said second spring means for relieving tension in the member, said second cam means also being movable to an opposite position causing said second spring means to tension the member, and a cam actuator for sequentially moving said first cam means to its said active position and then moving said second cam means to its said opposite position and then moving said second cam means to said one position and then moving said first cam means to said inactive position.

3. A plate clamp for releasably securing and tensioning a iiexible member on a mounting surface comprising an elongated support plate mounted for limited movement with respect to said surface, clamping means mounted on said plate and movable to a first position for cooperation with said plate in clamping one end of the member to said plate and also movable to a second position releasing the one end of the member, rst spring means urging said clamping means forward to said second position, a first cam means operable on said clamping means and movable between an active position holding said clamping means in said lirst position and an inactive position wherein said first spring means moves said clamping means to its said second position for moving said plate to a tensioning position for applying tension to the member, second cam means connected to move said plate against said second spring means to relieve tension in the member, said second cam means also being movable to an opposite position causing said second spring means to tension the member, and singular can actuator means operable to move said vfirst cam means to its said active position and thenito move said second cam means to its said opposite position.

4. A plate clamp for releasably securing and tensioning a flexible member on a mounting surface, comprising an elongated support plate mounted for limited movement. with respect to said surface, clamping means mounted on said plate and movable to a irst position for cooperation with said plate in clamping one end of the member to said plate and also movable to a second position releasing the one end of the member, first spring means urging said clamping means to said second position, a cam bar operable on said clamping means and movable between an active position holding said clamping means in said first position and an inactive position wherein said first spring means moves said clamping means to its said second position, second spring means urging said plate toward a tensioning position for applying tension to the member, a tensioning cam operable to move said plate against said second spring means to relieve tension in the member, said tensioning cam also being movable to an opposite position causing said second spring means to tension the member, said cam bar and said tensioning cam being operably interconnected in angularly offset relation for positioning said cam bar in said active posi tion before said tensioning cam is moved to said inactive position.

5. A plate clamp for securing releasably one end of a flexible member to a support surface and for applying tensioning to the member, comprising an elongated support plate mounted for movement with respect to said surface, clamping mean-s substantially coextensive with said support plate and mounted thereon for pivotal movement between a clamping position wherein said clamping means cooperates with sm'd plate to clamp the one end .of the iiexible member therebetween and an unclamping position wherein said clamping means releases the one end, a cam bar mounted on said support plate for movement between an active position wherein said clamping means is moved to said clamping position and an inactive position wherein said clamping means is moved to said unclamping position, a tensioning cam operable to move said supoprt plate between one position wherein tension is applied to said member and an opposite position wherein said tension is relieved, said cam bar and said tensioning cam being secured together in angulariy offset relation for positioning said cam bar in said active position when said tensioning cam is in said opposite position.

6. A plate clamp for releasably securing and tensioning a flexible member on a mounting surface, comprising an elongated support plate mounted for limited movement with respect to said surface, clamping means substantially coextensive with and mounted on said plate and movable to a Iirst position for cooperation with said plate in clamping one end of the member to said plate and also movable to a second position releasing the one end of the member, spring means for moving said clamping means to said second position, a cam bar mounted on and substantially coextensive with said plate and movable between an active position holding said clamping means in said first position and an inactive position wherein said spring means moves said clamping means to its said second position, iirst means for moving said plate toward a tensioning position for applying tension to the member, a tensioning cam rigidly mounted on said cam bar in angularly oifset relation for moving said plate to relieve tension in the member and also for movement to an opposite position for permitting said iirst means to move said plate to said tensioning position, and cam actuator means connected to said cam bar for moving said cam bar to its said active position and then moving said tensioning cam to its said opposite position.

7. A plate clamp for releasably securing and tensioning a liexible member on a mounting surface, comprising an elongated support plate mounted for limited movement with respect to said surface, clamping means substantially coex-tensive with and mounted on said plate and movable to a irst position for cooperation with said plate in clamping `one end of the member to said plate and` also movable .to a second position, releasing the one end of the member, spring means for moving said clamping means to said lsecond position, a cam bar mounted on and substantially coextensive with saidplate and movable `between an active position holding said clamping means relation on said earn bar for moving said tensioning cam 10 E to and from its said opposite position only when said cam bar is in said active position, and cam actuator means for moving said cam bar.

References Cited in the tile of this patent UNITED STATES PATENTS 1,765,530 Harrold June 24, 1930 FOREIGN PATENTS 840,745 Great Britain July 13, 1960 UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTIGN Patent No. 3,156, 184 November IOY 1964 Dar-1 TIa Shank It is hereby certified that error appears n the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 49, after "surface" insert a comma;

line 67, for "can"v read cam column 6, line 35, for

"supoprt" read support Signed and sealed this 30th day of March 1965a (SEAL) Attest:V A

ERNEST W. SWIDER` EDWARD J. BRENNER Attesting Officer Commissioner of Patents

Claims

1. A PLATE CLAMP FOR RELEASABLY SECURING AND TENSIONING A FLEXIBLE MEMBER ON A MOUNTING SURFACE, COMPRISING AN ELONGATED SUPPORT PLATE MOUNTED FOR LIMITED MOVEMENT WITH RESPECT TO SAID SURFACE, CLAMPING MEANS MOUNTED ON SAID PLATE AND MOVABLE TO A FIRST POSITION FOR COOPERATION WITH SAID PLATE IN CLAMPING ONE END OF THE MEMBER TO SAID PLATE AND ALSO MOVABLE TO A SECOND POSITION RELEASING THE ONE END OF THE MEMBER, FIRST SPRING MEANS URGING SAID CLAMPING MEANS FORWARD TO SAID SECOND POSITION, A FIRST CAM MEANS OPERABLE ON SAID CLAMPING MEANS AND MOVABLE BETWEN AN ACTIVE POSITION HOLDING SAID CLAMPING MEANS IN SAID FIRST POSITION AND AN INACTIVE POSITION WHEREIN SAID FIRST SPRING MEANS MOVES SAID CLAMPING MEANS TO ITS SAID SECOND POSITION, SECOND SPRING MEANS URGING SAID PLATE TOWARD A TENSIONING POSITION FOR APPLYING TENSION TO THE MEMBER, SECOND CAM MEANS OPERABLE ON SAID PLATE AND MOVABLE TO ONE POSITION TO MOVE SAID PLATE AGAINST SAID SECOND SPRING MEANS FOR RELIEVING TENSION IN THE MEMBER, SAID SECOND CAM MEANS ALSO BEING MOVABLE TO AN OPPOSITE POSITION CAUSING SAID SECOND SPRING MEANS TO TENSION THE MEMBER, AND SINGULAR CAM ACTUATOR MEANS OPERABLE TO MOVE SAID FIRST CAM MEANS TO ITS SAID ACTIVE POSITION AND THEN TO MOVE SAID SECOND CAM MEANS TO ITS SAID OPPOSITE POSITION.