US2179508A

US2179508A - Plate clamp for printing machines

Info

Publication number: US2179508A
Application number: US160218A
Authority: US
Inventors: George M Keller; William F Huck
Original assignee: R Hoe and Co Inc
Current assignee: R Hoe and Co Inc
Priority date: 1937-08-21
Filing date: 1937-08-21
Publication date: 1939-11-14
Anticipated expiration: 1956-11-14

Description

New. M, W39.

ou ao/ao ooll- G. M. KELLER ET AL PLATE CLAMP FOR PRINTING MACHINES Filed Aug. 2l, 1937 4 Sheets-Sheet l 7L L@ 25;@ M15;

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Filed ug- 21, 1937 L A R E L L E K M G PLATE CLAMP FOR PRINTING MACHINES M 31939- G. M KELLER Er AL.

PLATE CLAMP FOR PRINTING MACHINES Filed Aug. 2l, 1937 ENTORS )CQ/guy Sheets-Sheet 3 f Il f V f m v f Nov; M, 1939. G. M. KELLER ET A1.

PLATE CLAMP FOR PRINTING MACHINES Filed Aug. 2l, 1937 4 Sheets-Sheet 4 Mic/ INVENTQRS.

Patented Nov. 14, 1939 UNITED STATES PATENT OFFICE PLATE CLAMP Fon George M, Keller, Rochester,

Huck, Richmond Hill, N. Y.,

PRINTING MACHINES and William F. assignors to R.

Hoe & Co., Inc., New York, N. Y., a corpora- This invention relates to plate clamping means for printing and like machines, and more particularly to a plate clamping mechanism which includes a margin bar, arranged for use in securely clamping the straight edge of a curved printing plate to a form cylinder of a printing machine.

The plate clamping means of this invention is particularly adapted and arranged to engage the straight edge of a curved plate upon a form cylinder of a printing machine and hold it tightly thereagainst to prevent this plate edge from bowing upwardly away from the cylinder, due to centrifugal force developed when the cylinder is rotated or other cause. The clamping means of this invention includes a margin bar arranged on the cylinder to engage the straight edge of a curved printing plate, and means associated with this bar and actuated by centrifugal force developed by the rotative movement of the cylinder, to cause this bar to press against, and clamp, the plate to the cylinder by a pressure, which increases in proportion to the speed of rotation of the cylinder.

One object of this invention is to provide an improved plate clamping means of the above nature.

Another object is to provide in combination with a curved plate receiving cylinder, means actuated by centrifugal force developed when the cylinder is rotated, to securely hold a straight edge of the curved plate against the cylinder.

It is also an object of this invention to provide a plate clamping means of generally improved construction, whereby the device will be simple, durable and inexpensive in construction, as well as convenient, practical, serviceable and efficient in its use.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts, and in the details of construction hereinafter described and claimed.

The preferred embodiment of this invention is illustrated in the accompanying drawings, where- Figure l is a face view of a form cylinder of a printing machine, with plate clamping means embodying the features and principles of this invention associated therewith;

Figure 2 is an enlarged plan View of one end of a pair of printing plates and the margin bar constituting a part of the clamping means of this invention disposed between the straight edges thereof;

1937, Serial No. 160,218

(Cl. lOl- 378) Figure 3 is a longitudinal section taken on line 3-3 of Figure 2;

Figure 4 is a cross sectional view taken on line 4-4 of Figure 2 and showing the position of the parts when the cylinder is rapidly rotating;

Figure 5 is a cross sectional view similar to Figure 4 but showing the position of the parts when the cylinder is not rotating;

Figure 6 is a sectional view taken on line 6-6 of Figure 5;

Figure '7 is an enlarged plan view of one end of a pair of printing plates and a somewhat modifled form of margin bar constituting a part of the clamping means disposed between the straight edges thereof;

Figure 8 is a cross sectional view taken on line 8-8 of Figure 7;

Figure 9 is an enlarged plan view of another modified form of margin bar disposed between the straight edges of a pair of printing plates;

Figure 10 is a cross sectional View taken-on line Ill- Ill of Figure 9;

Figure 11 is an enlarged plan view of another modified form;

Figure 12 is a sectional view taken on line I2-I2 of Figure 11;

Figure 13 is an enlarged plan view of still another modiiied form; and

Figure 14 is a sectional view taken on line ll-fil of Figure 13.

The features and principles of this invention being especially adapted for association with the form cylinder of a printing machine, the drawings illustrate a form cylinder II having shaft ends I2 and I3 extending from its ends whereby it may be journaled in suitable supports (not shown) and be rotated to perform its usual function in combination with the other mechanisms of a printing machine. The cylinder Il is adapted to have a plurality of curved printing plates I4 mounted thereon and is provided with the usual curved edge clamping and locating members I5 and straight edge locating blocks I6. The plates Il generally extend peripherally about the cylinder I I and have the straight edges I1 and I 8 of one plate slightly spaced from, and in opposed relation to, the straight edges I1 and IB of another plate, the opposing edges of both plates being in abutment-with the edgel locating blocks I6.

The clamping members I5 impose a cross pressure upon the plates I4 and the rapid rotation of the cylinder II develops centrifugal force, both of which forces tend to bulge the centerof the plate I4 away from the cylinder. This bulging tendency is greatest at the straight edges I1 and I8 of the plates I4 for the central portions I8 are inherently stiifened by their arcuate formation. 'Ihis invention provides means to counteract this bulging tendency by the provision of margin bars 2I and 22, each having a shoulder 23 adapted to overlie a corresponding shoulder 24 formed on the straight edges I1 and I8 of the plate I4. Herein the margin bars 2| and 22 are shown provided with oppositely directed shoulders 23 whereby the shoulders 24 on the opposed edges I 1 and I8 of adjacent plates I4 will be simultaneously engaged.

The margin bars 2| and 22 extend lengthwise of the cylinder II along the straight edges I1 and I8 of the plates I4 and are each secured to a cylindrical weight 25, by means of a plurality of tie rods 28 which freely pass through openings 21 formed in the cylinder II. Each of the weights 25 is preferably disposed in an opening 28 formed in, and extending lengthwise of, the cylinder II and which is preferably disposed adjacent the periphery of the cylinder II and diametrically opposite the margin bar connected thereto. The openings 21 are preferably radially directed through the cylinder and are slightly larger in diameter than the rods 28 to permit a small amount of free movement for the margin bar in any direction. Likewise, the openings 28 are larger in diameter than the weights 25 to permit transverse movement of the weights therein. The bars 2| and 22 are connected to the rods 26 by screws 29 and the weights 25 are connected to the rods 26 by screws 3l.

Herein the weights 25 are shown somewhat longer than the margin bars 2| and 22, and these bars are shown somewhat shorter than a groove 32 provided in the cylinder I I to receive them. The margin bars 2l and 22 in this instance are T shaped in cross-section, the body portion being disposed in the groove 32 and the arm portions forming the oppositely directed shoulders 23.

'I'he groove 32 in which one of the bars 2| and 22 is disposed, is shown in communication with the openings in which the weight 25, connected to the opposite margin bar, is disposed. The tie rods 25 connecting one bar with its associated weight are shown passing through openings 33, formed in the weight connected with the opposite bar.

Each weight 25 is counterbored as at 34 to receive a compression spring 35. 'I'he counter-l bores 34 are herein shown in alignment with the tie rods 26, connected to the respective weight, and the spring 35 is therefore arranged to encircle the head of the screw 8| which is disposed in the counterbore. The springs 35 react between the bottom of the counterbores 34 and the undersurface of the margin bar overlying the respective weight which is connected to the opposite margin bar, whereby the bars 2| and 22 with their associated parts, tie rods 28 and weights 25 may be referred to as being floatingly mounted in the cylinder II. It will be obvious that, if margin bars are not diametrically opposed, the springs 35 can be arranged to react between the bottoms of the counterbores 34 and any suitable abutment secured to or forming part of the peripheral wall 36 of the cylinder II, and overlying the weight openings 28. Y

In thearrangement shown, the springs 35 in one weight 25 reacting against the margin bar connected to the opposite weight tends t0 reate an equalizlng effect whereby the action of the opposite margin bars 2l and 22 will engage the respective plate edges I1 and I8 with substantially equal pressure. Preferably the springs 85 are tensioned only sumciently to counterbalance the weight of the parts associated therewith and not sufllciently to interfere with the movements of these parts to press the margin bar upon the plate edge to clamp the straight plate edge to the cylinder II.

'Ihe margin bars 2| and 22 are forced against the straight plate edges I1 and I8 due to centrifugal force developed by rotation of the cylinder Il and acting on the weights 25 to throw them outwardly.' Movement of the weights transversely in the openings 28 will, through the tie rods 28, press the margin bar shoulders 23 against the corresponding shoulders 24 on the opposed straight edges I'I and I8 of the plates I4, to clamp these edges tightly to the cylinder II. Obviously, the faster the cylinder II rotates the .more centrifugal force is developed and hence the pressure of the margin bars 2I and 22 upon the plate straight edges will be correspondingly increased, thus overbalancing the tendency for these edges to bulge as above described, and maintaining them tightly against the periphery of the cylinder II.

In the form shown in Figures 7 and 8, the margin bar, disposed between the opposing straight edges I1 and I8 of the plates I4, is constituted by members 4I' and 42, each having a flange 43 extending along its outer edge to provide oppositely directed shoulders 44 adapted to overlie the corresponding shoulders 45 formed on the straight edges I 1 and I8. 'I'he abutting surfaces between the shoulders 44 and 45 are inclined from 4the plate edges I 'I and I8 outwardly toward the periphery whereby when the members 4I and 42 are spread apart the plates I4, at their edges I1 and I8, will be more firmly pressed against the cylinder II.

'Ihe means to spread the members 4I and 42 apart includes a weight 48 disposed in a longitudinally extending opening 41 formed in the cylinder II adjacent its periphery and directly below the plate straight edges I 1 and I8. The weights 46 are normally pressed radially outwardly by springs 48 and are guided in any radial movements by studs 49 which extend through the weights and into the cylinder II from a member spreading bar 5I. Each bar 5I has a base 52 seated in a groove 53 formed in the respective weight 46 and extends radially outwardly therefrom between the members 4I and 42. Adjacent the weight 46 the side surfaces of the bar 5I are inclined toward each other as at 54 from the base 52 to an intermediate straight portion 55, the side surfaces of which are parallel, and then the side surfaces are again inclined toward each other as at 56.

Intermediate the inclined side surfaced

portions

54 and 56 of the bar 5I and the adjacent members 4I and 42 non-friction members 51, such as hardened steel rods, may be disposed in recesses 58 formed in the members 4I and 42 against which these inclined surfaces act to spread the members 4I and 42, when centrifugal forge urges the weights 46 outwardly. The spreading action of the members 4I and 42 tends to force the inclined surfaces 44 of the members 4I and 42, peripherally over the inclined surfaces 45 of the plate edges I1 and I8 respectively, and increasing centrifugal force developed by increasing speed of rotation of the cylinder II will increasingly clamp the plate edges I1 and I8 against the cylinder. l

In the form shown inFlgures 9 and 10, the margin bar disposed between the opposing straight edges I1 and I8 of the plates I4 is constituted by a pair of cooperating members 6| and 62, each having a flange 63 extending along its outer edge to provide oppositely directed shoulders 64 adapted to overlie corresponding shoulders -05 formed on the straight edges I1 and I8. As in the previously described form, the abutting surfaces between the shoulders 64 and 65 are inclined so that when the flanges 63 of the members BI and 62 are spread apart these edges will be more rmly pressed against the cylinder II.

lI'he members 6| and 62 extend from the flanges 63 into the cylinder II through a slot 66, and have their inner edges fulcrumed respectively on the opposing inner edge 60 of the slot 66 where it joins an opening 61 extending longitudinally through the cylinder II adjacent its periphery and directly beneath the plate edges I1 and I8. Each of the members 6I and 62 is provided with a finger-like extension or extensions 68, the ends 69 of which are adapted to seat upon a flattened area 1| formed on a weight 12 disposed in the openings 61. A curved fulcrum surface 'I3 is provided between and on each of the members 8| and 82 whereby when the fingers 68 are spread by the action of the weight 12 being urged outwardly by centrifugal force the flanges 03 will be spread apart. Springs 14 are provided to react between the surface of the openings 61 and the weights 12 to constantly maintain the parts in engagement.

In the form shown in Figures l1 and l2, the margin bar is constituted by a plurality of members 8I and 82, each having a flange 83 extending along its outer edge forming a shoulder 84. The members are disposed in juxtaposed position with the flanges 83 oppositely directed whereby the shoulder 84 of one will overlie the straight edge I1 of one plate and the shoulder 84 of the next adjacent one will overlie the straight edge I8 of the other plate. The members 8| and 82 extend into the cylinder II and are each secured to a curved plate 85 disposed in a longitudinally extending opening 86 through a slot 81.

An edge 88 of each of the plates 85 is adapted to seat upon one of a series of shoulders 89 alternately formed on the sides of a weight 9| disposed in length to extend under all of the members 8| and 82. The other edge 92 of each of the plates 85 overlies a hole 93 formed in the side of the weight 9| opposite each of the shoulders 89 and is engaged by a spring 94 seated in the hole 93.

When the cylinder II is rotating rapidly, the parts assume the positions shown in Figures 11 and 12, the weight 9| being urged outwardly toward the periphery of the cylinder by centrifugal force. Movement of the weight 9| toward the periphery of the cylinder I has moved the curved plates 85 within the opening 86 against the tension of the springs 94 and the shoulders 84 of the flanges 83 have engaged the respective printing plate edges I1 or I8 to securely clamp the plates to the surface of the cylinder II. When the cylinder cornes to rest, the springs 94 will reversely move the curved plates 85 to release the clamping engagement of the shoulders 04 of the flanges 83 with the plate edges I1 and I8.

Referring to the form shown in Figures 13 and 14,

members

96 and 91 extend through a slot the opening 86 and which is of suilicient 98 formed in the cylinder II from a sleeve member 99 disposed in a longitudinally extending opening |0| formed in the cylinder II.v Each

member

96 and 91 is provided with a flange |02 forming a shoulder |03 which is adapted to overlie the adjacent straight edges Il'and I8 respectively of the printing plates. The

members

96 and 91 are arranged in juxtaposed position inl the cylnder and have their flanges |02 alternately directed to engage opposing printing plate edges.

A weight |04 extends through all of the sleeve members 99 and is connected to each member by a lug |05 extending inwardly from the internal periphery of the members 99 into a slot |08 provided in the weight. The lugs |05 of the members 99 are disposed on the side of the member opposite to that side toward which the flanges |02 extend and the members 99 are assembled on the weight |04 "'ith the lugs |05 of adjacent members alternately directed, whereby movement of the weight |04 outwardly under the urge of centrifugal force when the cylinder |I is rotated will cause the alternate sleeve members 99 to oppositely twist and the flanges |02 on the

respective members

96 and 91 will therefore clampingly engage the printing plate edges I1 and I8 respectively as shown in Figures 13 and 14. Springs |01 disposed in holes |08 formed in the weight |04 will react between the weight and each of the sleeve members 99 to twist the latter back into their normal position when the cylinder stops rotating.

It will be understood that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, and it will be further understood'that each and every novel feature and combination present in or possessed by the means herein disclosed forms a part of the invention included in this application.

What we claimis:

l. In plate clamping mechanism for the form cylinder of a printing machine adapted to use pre-curved printing plates, a margin bar arranged to operably move radially with respect to the axis of the cylinder, to engage a straight edge of a plate and clamp it to the cylinder, and a weight connected to the margin bar whereby it is moved to clamp the plate when the machine is operated.

2. In plate clamping mechanism for the form cylinder of a printing machine adapted to use curved printing plates, a movable margin bar, and means actuated by centrifugal force to operably move said bar into engagement with an edge of a plate on the cylinder and clamp it to the cylinder.

3. In mechanism for clamping a curved plate to the form cylinder of a printing machine, a movable margin bar extending lengthwise along and over a straight edge of the plate, and centrifugally affected means to. move said bar into clamping engagement with the plate straight edge to secure it to the cylinder.

4. In mechanism for clamping a curved plate to the form cylinder of a printing machine, a margin bar extending along and over an edge of -the plate, and means actuated by centrifugal force developed by the rotation of said cylinder to cause said bar to engage and clamp the plate to the cylinder by pressure varying with the rotative speed of said cylinder.

5. In a printing plate clamping mechanism, a

margin bar adapted to extend along and over an edge of the plate and being arranged to be operably moved into engagement with the plate edge and to clamp it to a cylinder of a printing ma- 5 chine, means actuated by centrifugal force developed by the rotation of the cylinder to so move the bar, and means to move said bar out of engagement with said edge.

6. In a printing plate clamping mechanism, a

margin bar adapted to extend along and over an edge of the plate and mounted adjacent the plate edge to be operably moved into engagement with the plate edge and to clamp it to a cylinder of a printing machine, and a weight connected to said bar and actuated by centrifugal i'orce to so move said margin bar.

7. In a printing plate clamping mechanism, a rotatable cylinder, a margin bar arranged to overlie a straight edge of a printing plate on said cylinder, and a weight carried by said cylinder to be acted upon by centrifugal force developed by the rotative movement of said cylinder to move said bar into engagement with the edge of said printing plate and clamp it to said cylinder.

8. In a printing plate clamping mechanism for securing printing plates to a rotatable form cylinder of a printing machine, a margin bar adapted to overlie a straight edge of the printing plate, and a weight connected to said bar and movable by centrifugal force to cause said bar to clamp the plate edge to the cylinder.

9. In a clamping mechanism for securing printing plates to a rotatable form cylinder of a printing machine, a movable margin bar adapted to overlie an edge of the printing plate, and a weight operably connected to said bar and carried by said cylinder to be affected by centrifugal force due to the rotative movement of the cylinder to cause said bar to clamp the plate to the cylinder.

10. In a mechanism for securing a curved plate upon a rotatable form cylinder of a printing machine, a margin bar mounted on the cylinder to overlie and moved toward an edge of the plate, and a radially movable weight carried by the cylinder and connected to said bar to move the bar into clamping engagement with the plate edge when the cylinder is rotated.

1l. In a plate clamping mechanism for securing a curved plate upon a rotatable form cylinder of a printing machine, a margin bar mounted on the cylinder to overlie and move toward an dge of the plate, a weight carried by the cylinder and connected to said bar to move the bar into clamping engagement with the plate edge when the cylinder is rotated, and resilient means to release the bar from clamping engagement with the plate edge when the cylinder is at rest.

12. In a plate clamping mechanism for securing curved plates upon a rotatable form cylinder of a printing machine, an inwardly movable margin bar disposed between opposing plate edges and being adapted to overlie each edge, a weight carried by the cylinder and arranged to move 14. In a plate clamping mechanism for secur- A ing a pair of substantially semi-cylindrical curved plates to a rotatable form cylinder of a printing machine, movable margin bars carried by the cylinder adjacent to and overlying adjacent straight edges of the plates, a centrifugally movable weight connected to each bar and being disposed adjacent the other bar, whereby centrifugal force developed by the rotation of said cylinder will cause said bars to engage the respective plate edges adjacent thereto.

15. In a plate clamping mechanism for securing a pair of substantially semi-cylindrical plates to a rotatable form cylinder of a printing machine, movable margin bars carried by the cylinder adjacent to and overlying opposite straight edges of the plates, centrifugally movable weights carried by the cylinder each connected to one bar and disposed adjacent the other bar, whereby centrifugal force developed by the rotation of said cylinder will cause said bars to engage the plate edges adjacent thereto, and a spring acting against each weight to hold said bars out of engagement with the plate edges, when the cylinder is at rest.

16. In mechanism to clamp a plate to a cylinder, a margin bar adapted to extend along and over an edge of the plate and being arranged to be moved radially with respect to the cylinder into engagement with the plate edge to clamp it to the cylinder, and means actuated by centrifugal force developed by the rotation of the cylinder to so move the bar.

1'7. In mechanism to clampfaiplate to a cylinder, a margin bar adapted to extend along and over an edge of the plate and being arranged to be moved peripherally with respect to the cylinder into engagement with the plate edge to clamp it to the cylinder, and means actuated by centrifugal force developed by rotation of the cylinder to so move the bar.

18. In mechanism to clamp the opposing edges of plates to a cylinder, a member adapted to extend along and over each edge and being arranged to be moved peripherally with respect to the cylinder into engagement with the respective plate edge to clamp it to the cylinder, and means actuated by centrifugal force developed by the rotation of the cylinder to simultaneously move said members.

GEORGE M. KELLER.

WILLIAM F. HUCK.