US1759476A - Work-supporting member for printing machines - Google Patents

Description

F. M. ALLEN WORK SUPPORTING MEMBER FOR PRINTING MACHINES Original Filed Sept. 10, 1927 May 20, 1930.

- ATTORNEY X Q x INVENTOR ALL N Fatented May 20, 1930 UNITED STATES PATENT OFFICE FRANK M. ALLEN, or SUMMIT, NEW JERSEY, ASSIGNOR 'ro GoNGoLEUM-NAIRN, Inc, A CORPORATION on NEWHYORK' WORK-SUPPORTING MEMBER FOR IPRIN'IING MACHINES Beflled for abandoned application Serial No. 218,636, filed September 10, 1927. This'applieation filed March 21, 1930. Serial No. 437,647.

This invention relates to printing machines, and more particularly to printing machines of the bed-and-platen type as de scribed and claimed in the Waldron Patent No. 1,145,821.

Printing machines of the type referred to, comprise, in general, a set ofplatens carrying printing blocks, which are adapted to be reciprocated by suitable mechanism to impress a design upon a base material as it is conveyed step by step through the machine over the bed and work-supporting members. In the present-day machines, the work-supporting members consist of fiat pads each having a wood backing and a top of wool felt of uniform thickness, covered with oilcloth or similar material. The pads are suitably cradled in the framework of the print machine beneath the set of platens, the felt faces being adapted to provide flat, compressible work-supporting surfaces, against which the print blocks may abut without injury to their printing surfaces. Intermediate the worksupporting members orpads, and in a plane therewith, are wood or steel plates, forming with said pads a continuous flat bed over which the work is conveyed. As thefiat print block is brought into association with the work supported by the flat felt pad for the purpose of depositing paint thereon, or for flattening or mashing the paint previously deposited, a strong cohesive relation is set up between the print block and the work, whereby the raising of the print block from the printed surface is opposed with great resistance. This efi'ect is particularly noticeable when a relatively heavy layerof paint is being deposited, as, for example, when decorating hard-surfaced floor coverings with a film of paint of suflicient thickness to form a wearing surface. In consequence, the work is slightly raised 1 from the work-supporting member by the suction of the block, until the opposing forces break the bond and the work is suddenly torn from the block. Frequently this results in spattering the paint and in many'instances the paint is raised in pits and points so that the work has an uneven and rough appearance. With relatively slow reciprocation of the platens and blocks, this defect, while apparent, is not serious, but as the speed of operation is increased, the defect becomes most serious and functions as one of the chief factors in limiting the printing capacity of the machine. v The chief object of my invention is to provide a novel work-supporting member for print machines of the bed-an'd-platen type, which is of simple and durable construction and which is adapted to substantially eliminate the defect outlined above and to permit an increased speed of operation.

In the accompanying drawings, forming a part of this'specification:

Figure 1 illustrates a portion of a conventional bed-an'd-platen print machine, embodying the novel work-supporting members con-,

structed in accordance with the principles of my invention;

Figure 2 is a longitudinal elevation of said work-supporting members;

Figure 3 is an enlarged sectional elevatio taken on the line33 of Figure 2;

Figure 4 is a sectional elevation of a modified form of, work-supporting member likewise embodying the principles of my invention.

Referring to the drawings: 7

1 designates the platens of a bed-and-platen type print machine, carrying the flat print blocks 2. Beneath'the platens and forming a continuous surface over which the work to be printed is conveyed step by step through the machine, is the bed 3 supported by the framework 4. The bed consists of pads or work-supporting members 5 positioned beneath each platen and intermediate members or plates 6 of metal or wood. Preferably, the pads or work-supporting members 5 are removably cradled in the frame 4, whereby they may be easily replaced in case of wear or damage.

According to the principles of my invention, the pad or work-supporting member 5 is of resilient construction having a worksupporting surface which is-normally conures 2 and 3, I have shown a preferred form of construction of work-supporting member or pad. Such pad comprises a backing mem- "ber 10 of laminated wood slightly greater in surface area than'the. surface area of its cor-g responding print block. Along each upper longitudinal edge of the member 10 and attachedthereto are'grooved metal strips 11 7 adapted to support and retainwa normally convexed spring steel plate 12. The relation of the plate'12 totheretaining members 11 is such as to permit free flexing movements of the former, while preventing any substantial lateral movementthereof. Over the plate 12 is a thick layer of felt 13 adapted to provide a relatively soft surface against which the print block may abut without injuryto the printing surface thereof. Preferably, the felt is covered with a good grade of oilcloth 13 providing a surface of low friction, over which the work may pass.

a print block, should, in all events, be comparable with the normal downward pressure exerted by the blocks and platens during the printing operation. ,I have found it most desirable that the force required should be considerably less than such printing pressure,

- in order to insure a complete flexing of 'the pad to conform with the surface of the print block. Preferably, the plate 12 is so tempered as to exert a substantially uniform upward pressure over its entire surface when flexed to a flat work-supporting surface, so

is obtained. Y

that a uniform impression of the print block In Figure 4, I have'shown a modifiedform usual manner.

of resilient convex work-supporting member,

consisting of a sponge rubberblock 15', suitably cradled in the supporting member 16. The sponge rubber block is preferably moulded in such double convex form as to exert a uniform'upward pressure when the worksupporting surface is compressed by the print block to the planethereof. Other suitable compressible elastic material may be substituted for the sponge rubber if desired.

In the operation of a bed-and-platen type printingmachine embodying my invention, the platens and blocks are reciprocated in the 'upon the work supported by the convex resilient pad, there is line-contact engagement of such block and work at the center y of the pad in contrast with the overall plane- As the print block descends contact engagement as in the present-day machines. As the print block is forced into further engagement by extended line-contact under the pressure exerted by the platen, the Work-supporting member is flexed to conform with the surface of the flat block, thereby causing a complete and uniform contact of the print block with the work. As the 7' print block, having reachedthe end" of its" downward stroke, commences its upward movement, the work still firmly held between the block and. the center of the resilient pad,

is separatedfrom the blockat the edges 0;

smoothly and easily by the line-contact disengagement, as shown in Figure 1. The pad continulngto flex toits normal convex position as'tlie block'recedes,the;line-contact disengagement of the work and print block continues until the two are entirely separated."

This feature of line-contact disengagement, similar to-the peeling. action in rotary printing machines, entirely avoids the sudden plane-cleavage of the bond between the print block and the work. Furthermore, such operationsubstantially eliminates all spattering occurring from the sudden separation of the print block and work, and avoids the formation of pits and points of paint.. Of chief importance, however, is the fact thatby employing work-supporting members having 3 the characteristics of myinvention, Iamable to obtaina considerably increased speed of reciprocation of the printblocks,'which results in increased capacity of the print machine, and at the same time produces prints which have a uniformand even finish.

It will be obvious to those skilled in' the art that numerous modifications may bemade in the manner of carrying out my invention,

and I do not wish to limit its scope, except as defined in the appended claims. .1. :J I

This application isa rerfile of application,

Serial No. 218,636, filed September 10th,

* 1. In a bed=and-platenf combination, a printing member having a flat printing surface and. arresilient work-supporting member, including a normally convexed spring plate, adaptedto be flexed to a substantially flat work supporting surface during the printing operatio combination, a flat'block printingmembe'r and a resilient work-supportingmember, said work-supporting member having a normally convexed work-supporting surface adapted to be flexed to a substantially flat work-supporting surface during the printing opera tion.

3. In a bed-and-platen print machine, in combination, a flat block printing member and a resilient work-supporting member, said work-supporting member being adapted to cause line-contact engagementand disen i p i V print machine, in

2. In a bed and-platen:print machine, inf I gagement of the printing member and the Work.

4. In a bed and platen print machine, in combination, a resilient normally convex Work supporting member, adapted to flex under printing pressure to provide a .flat Work supporting surfaoe, and a printing member having a flat printing surface and adapted to reciprocate toward and from the Work supporting member, and to flex the latter into the plane of the former.

5. In a bed-and-platen print machine, in

combination, a printing member having a flat printing surface, and a resilient work supporting member adapted to provide a flat Work-supporting surface during a portion of the print period and to cause line contact disengagement of the printing member and the Work. 7

In testimony whereof, I aflix my signature. FRANK M. ALLEN.

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