US2218451A - Stencil screen construction - Google Patents

Description

0t.15, 1*940. c. A HEYNE 2,218,451

' sTENCIL SCREEN CONSTRUCTION Filed Sept. 27. 1938 IFM., 6.V liz-7 ,14 IN VEN TOR.

61A. HEYNE vllatenlzed Oct. 15,

f.fz,21 s,451

vPATENT .OFFICE sTENcn. SCREEN CONSTRUCTION Clarence A. Heyne, Alton, lll., assignor to Owens- Illinois Glass Company, a corporation of Ohio e Application September 27, 1938, Serial No. 23l,896 Claims. .(cl. 10i-127) The present invention relates to a stencil screen construction and more particularly to a screen unit adapted `for use either by ahand operation, or in a machine of the type in which the rstencil 5 screen is caused to move in tangential rolling line contact with the curved surface l of an article undergoing decoration while at the same time a vitreous enamel composition isv forced through the pervious portions of the screen by the spreadl0. ing action of a squeegee. The screen unit comprising the present invention is also adapted for usein the decoration of the iiat surfaces of articles by the usual process whereinA the screen is placed in stationarycontact with theflat surface l5` andthe squeegee is caused to traverse the pervious portions of the` screen.

In screen units of this type, the screen is usually held taut on an open rectangular screen frame formed oi' wood or other material to which the edges of the screen are glued, stapled or otherwise fastened, the whole formingl a rectangular box-like structure and' the screen forming the bottom thereof. The stencil screen material for screen units of the type just mentioned is usually a specially woven imported silk fabric, the normal J life of which is relatively short. Efforts have been made to employ a specially woven metal screen mesh in a construction of this nature because of the far longer screen life-attendantupon the use of the metal material. However, experience has proven that in such a. construction, if the screen comes into contact with the articleundergoing decoration, or with the article-supporting chuck or other part of the decorating apparatus along the edge. of the frame over which the screen is stretched, the transverse strands of the metal mesh will be come severed, thus necessitating` a new Screen.

It has been proposed to remedy the above ob.-

1jectionable conditions by the application of a sponge rubber or other resilient lining tothe underneath side of the frame on all four sides thereof over which the 'metal screen' may be stretched inthe usual manner. Such a `remedy is not entirely satisfactory in that there is a tendency for the transverse strands of the screen mesh to become severed along the lines described by screen mesh material is employed in connection With'a stencil screen frame.

The present invention is designed to overcome the above' mentioned objectionable characteristics of stencil screen unit design, particularly where a metal screen mesh.is employed,lby the provision of a mounting for the stencil screen wherein the tension in the short transverse strands of the screen material may be relieved to avoid severing thereof by the squeegee. cipal object ofthe invention` -it is another objectA to provide a stencil screen construction wherein the tension of the screen both laterallyand transversely maybe adjusted at will. A still further object is to provide a stencil screen unit of the 15l type'set forth above in which means is provided for permanently anchoring the ends` of the longitudinal and transverse strands Aoi the mesh in fixed position against unraveling o1' becoming frayed.` Yet another object of the invention is to 20 provide such a stencil screen construction in which the screen may be readily removed and replaced atwill.

The provision of a'sten'cil screen unit which is relativelyI simple in its construction, one which 25 may be set up for use and assembled in a stencilling machine witha minimum of eifort, one .which maybe manufactured at a low cost, and one which is rugged and durable and which consequently is unlikely to get out of order are further desiderata 30 that havebeen borne in mind in the production and development of the present invention.-

. Other objects and advantages of the invention will become 'apparent hereinafter.

In the accompanying drawing:, 35

Fig. l is a perspective view of-a stencil screen unit constructed in accordance with the principles of the present invention;

Fig. 2 is a sectional view taken along the plane indicated by the line 2--24 of Fig. l; 40

Fig. 3 is a sectional view taken along the plane vvindicated by the line 3 3 of Fig. l;

Fig. 41s a sectional view similar-to Fig. 3 showing a modled form of attaching means for the stencil screem' and Y 45 Figs. 5, 6 and 7 are fragmentary sectional views, diagrammatic in their representation, illustrating the manner in, which thestencil screen is reinforced at the edges thereof.

The stencil screen unit involves lin -its general organization a closed substantially rectangular metal frame I0 which is angular in cross-section and including longitudinal side bars l I and transverse end bars i2. The side and end bars Il and I2 are each provided with a Horizontal out- This. being the prin- 10 V heads of a like number of suspension screws I6.

' bars I2.

Suspended from the suspension screws and individually ladjustable vertically of the frame I0 are a. plurality of sub-frame members I1 which are substantially coextensive with the various respective side bars and end bars of the frame I0. Each of the sub-frame members I1 is formed with a horizontally extending flange I 8 which is reversed upon itself to provide a wall of double thickness in which the suspension screws I6 are threadedly received. Each sub-frame member I1 also includes a vertical attachment flange I9 adapted to bear against the vertical'ilange I4 of its respective side bar I I or end bar I2 as the case may be when the screen unit is assembled. The lower edge of each sub-frame member I'l is turned outwardly as at 20 and is adapted toreceive thereover the curved and reinforced edges of a stencil screen S which is thus stretched across the open frame I0 and forms the bottom of the open rectangular box-like structure. y

, Referring now to Figs. 3, 5, 6 and 7 wherein the manner of reinforcing the screen edges is disclosed, each edge of the screen S is reversed upon itself as indicated at 2| in Fig. 5. A metal rein- -forcing strip 22 which is U-shape in cross-section vreinforcing 'strip are bent into curved form. as

A strip 23 of resilient material, such as sponge rubber, is received between the screen S and the lower edge of each of the end bars I2 to prevent rupture of the strands of the screen should the latter contact any part of the decorating machine to which the screen unit is applied along the regions which are in contact with the end I'he strips 23 also serve to space the screen in' the regions of the longitudinal edges thereof from the side bars I I and thus materially reduce the tension of the transverse strands of the metal screen material.

It is to -be noted that thel suspension screws I6 are slotted to facilitate turning thereof in order that the tension of the screen which is stretched in one direction over the resilient strips 23 may be -adjusted so that any transverse slack existing in the screen may be taken up.

In Fig. 4 wherein a modified form of screen suspension is shown, an edge of the screen has vulcanized thereto one edge of a strip 23' of rubber material While the other edge of the strip 23' is vulcanized to one of the sub-frame members I1 at the lower edge of the latter, a' series ofapertures 24' formed at the lower edge of the subi'rame member Il serving toincrease the eil'ectiveness of the vulcanized joint. The strip 23 is stretched across the lower edge of the'frame I0.

I It is to be noted that the rubber strip 23' extends and connected thereto, the lower4 edges of the v screen frame projecting below the level oi the lower edges of the sub-frame, a stencil screen having its edges secured to the edges of the subframe and extending across the screen frame,

and a strip of yieldable material disposed between l the screen and lower edges of the screen frame at opposite ends of the latter.

2. A stencil screen unit comprising a screen frame, a sub-frame suspended from and surrounding the screen frame, the lower edges of the screen frame projecting below the level of the lower edges ofthe sub-frame, a stencil screen having its edges secured to the edges of the subframe and extending across the screen frame, a strip of yieldable material disposed between the screen and lower edges of the screen frame at opposite ends of the latter and serving to space the operative decorating portion of the screen below the plane of the lower edges of lthe screen iframe, and means for raising and lowering the sub-frame relative to the screen frame.

3. A stencil screen unit comprising a rectangular screen frame including side bars and end bars,

a four-piece sub-frame' surrounding the screen frame andincluding side members which are substantially coextensive with said side bars and end members and which are suspended from and are substantially coextensive with the end bars, the lower edges of the screen frame normally projecting below the lower edges of the sub-frame members, a stencil screen having its edges secured to the edges of the sub-frame members and extending across the screen frame, a strip of lyieldable material disposed between the screen and the lower edge of each end bar, and means for individually adjusting the position ofthe sub-frame members relative to the screen frame.

4. A stencil screen unit comprising a rectangular screen frame including side bars and end bars. a four-piece sub-frame surrounding the screen frame and including side members which are supported by and are substantially coextensive `with the side bars and end members which are supported by and are substantially coextensive with lthe end bars, the lower edges of the screen frame normally projecting below the lower edges of the sub-frame members, a stencil screen having its edges secured to the edges of the sub-frame members and extending across the screen frame, a strip of yieldablematerial disposed between the screen and the lower edge` of each end bar, and means foradjusting the position of the sub-frame end members relative to the screen frame.

5. A stencil screen unit comprising a rectangular screen frame whichis of right angle crosssection and having vertical anges and outwardly extending horizontal ilanges at the upper end of the former, sub-frame members adjustablysuspended from each of the outwardly extending horizontal ilanges, each sub-frame member including a lateral suspension flange and a verti` cal attachment flange, the lower edges of said attachment anges being turned outwardly and upwardly, a rectangular stencil screen, and a substantially inverted U-shaped reinforcement member secured to each edge of the screen and being receivable over the outwardly and upwardly turned lower edges of the sub-frame members.

CLARENCE A. HEYNE.

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