US2818803A

US2818803A - Silk screen stencil and holder

Info

Publication number: US2818803A
Application number: US440567A
Authority: US
Inventors: Alvin K Levorson
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-06-30
Filing date: 1954-06-30
Publication date: 1958-01-07
Anticipated expiration: 1975-01-07

Description

Jan. 7, 1958 A. K. LEVORSON 2,818,803

SILK SCREEN STENCIL AND HOLDER Filed June 30, 1954 FIG. L

mmvrox ALVIN K. LEVORSON BY paratus and methods of manufacturing and using the same.

According to the usual prior art, the silk screen process for printing is restricted to the use of relatively large silk screen frames over which the silk can be readily stretched taut and tacked in place and which can be used under such circumstances as to maintain the silk more or less in a plane. According to the present invention, relatively small silk screen apparatus can easily be made and can be used in situations where it is desirable or necf3) essary to print on a curved surface. Thus the apparatus of the present invention can be used to substitute for stencils, taking advantage of all the known superiorities of silk screening over stenciling.

A principal object of this invention is to provide silk screen apparatus which is pliable, for use on and appli- 35 cation to curved surfaces as well as to plane surfaces.

Another object of this invention is to provide a method of making relatively small silk screen devices, including both rigid-frame types and other types, which are more or less pliable and thus adaptable for both flat and curved surfaces, and of making the same in a simple'and economical manner.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection wit the accompanying drawings wherein:

Fig. 1 is an isometric view of one preferred embodiment of an apparatus made according to the present invention; Fig. 2 is an isometric view showing the use of several print on involve the use of either stencils or cut-out paper masks of the type which adhere to the surface to be marked.

Ordinary stencils sulfer from the defect of not producing the most desirable type of legible characters and the paper mask system suffers from the defect of requiring extra time .of the craftsman to return to the job when the paint has set and peel ofi the masks and trim up the work.

Also, the paper mask system is relatively expensive in k that the lettering masks can be used only once and must then be discarded.

The ordinary silk screen process, requiring a rigid frame on which the silk is stretched taut and then tacked in place, is not adaptable for printing on curved surfaces nor for use with relatively small frames where there would be considerable difliculty in stretching and tacking the fabric.

Patented Jan. 7, 1958 According to the present invention, a relatively small silk screen printing apparatus can be provided, which can be flexible so that it can substitute for a stencil or a paper mask, and this apparatus is produced according to a method of the invention which facilitates easy manufacture of such small frames.

References is now made to the drawings.

In Fig. 1, illustrating one preferred embodiment of an apparatus of the present invention, the numeral 2 indi- 1 cates a piece of silk or the like of the type used in the silk screen process. It is generally rectangular in form and is shown as already having applied to it the usual cut-out film, leaving a section of the screen pervious to paint or ink in the shape of a particular indicium, in this case the number 4. At each of the opposite ends. of the piece of silk there is cemented, or otherwise adhered or fixed to it, a rigid framing element. shown as 4 and 6, are conveniently made of thin metal but can be made of wood, plastic, or other suitable material. in opposite directions to maintain the silk taut, as required Means are provided to urge the ends of the silk.

These elements,

in the silk screen printing process, these means being illustrated in perhaps their simplest preferred embodiment as j a piece of spring wire 8 having loops 10 and 12 at the ends thereof adapted to engage hook-

like lugs

14 and 16,

respectively, conveniently formed by being punched out of the metal strips 4 and 6, respectively. The lugs are preferably provided with a short section 18 extending at right r angles to the plane of the framing elements and a second 1 section 20 extending generally parallel to the plane of the framing elements.

The spring wire 8 has a central arcuate portion 22 and lying generally in a plane transverse to the plane of the framing elements 4 and 6 and two end portions, designated as

arms

24 and 26, lying generally in the plane of the framing elements and terminating, respectively, in the aforementioned lug-engaging loops 1t] and 12. The

spring wire 8 is of such a size and is so preformed that a it tends to urge apart the ends of the

arms

24 and 26,

thus urging the framing elements 4 and 6 in opposite directions, maintaining tension on the silk 2 to keep it taut. The

lugs

14 and 16 are located centrally of the width of the silk screen so that the screen is maintained evenly stretched.

The arcuate portion 22 of the spring wire 8 is substantially as remote from the longitudinal center line of the rectangle of silk as is the long edge of the rectangle, so

that it does not interfere with access of the usual squeegee to the indicia appearing on the silk screen.

In using the apparatus in Fig. 1 to print on a flat sur- I face, the device can be held flat against the surface by pressing a thumb and finger against each of the loops The portion 22 of the spring wire 8 serves as a convenient handle or bail to lift off the device from the surface being printed. If

desired, the device can be held in place on the surface to be printed by the use of pressure-sensitive tape or the like.

Ih Fig. 2 thereisshown the use of several examples of the"device" of Fig. 1 in the process of printing several characters in one operation on a curved surface such as a length of pipe, a portion of an automotive vehicle body, or the like. The several silk screen devices are placed in the desired position on the object to be printed, preferably with a slight overlap as shown at 23 to avoid accidental printing of aline between adjacent screens. Conveniently, the group of screens can be held in their proper relative positions by the use of masking tape 30 or the like. With the screens in position, the paint or other printing material is applied in the usual manner with a squeegee 34. The remarkable flexibility of these screens enabling them to be used on curved surfaces even of relatively small radius of curvature, is due to the fact that there are no framing elements whatever along two of the opposite sides of the rectangular piece of silk, and these sides are therefore flexible and free of any rigid restraint.

When it is desired to remove the silk screen from the supporting spring to facilitate cleaning of the screen and storage, one of the framing elements is simply tipped up at an angle to the plane of the screen and the loop of the spring wire is readily disengaged from the lug on the framing element.

The novel method of this invention used to manufacture the silk screen printing unit of Fig. 1 and other em bodirnents of this invention is illustrated in Fig. 3. To prepare an ordinary rigid rectangular frame of small size adapted for use with a single small-size numeral, for example, is quite difficult inasmuch as it is hard to stretch and tack the silk on such small frames individually and obtain a tight and evenly-stretched screen. To avoid this difiiculty, the method of this invention contemplates tli'e'use of a conveniently large-size frame from which the smallerones are made. In carrying out the method, an ordinary size frame 36 is used. This is cut from a piece' of plywood or made in any other well known manner of a size which is large enough to make it easy to stretch and tack the silk on it. The silk 38 is then stretched andtacked or otherwise fastened to the frame in the usual manner. To make smaller silk screen printing'units', a small frame, such as 39 or 40, of the desired size, is obtained and glued or cemented or otherwise suitably fi'xed to the silk area in the large frame. Wood, metal, plastic, or the like can be used for these small frames. Fibe'rboardlsuch as Masonite, has been found quite satisfactory and when such material is used in a thickness ofabout of an inch, the small frame is found to be sufficiently flexible to bend around gently curved surfaces as well as'b eing' able to print on fiat surfaces. After the cement is dry, the smaller screens are cut from the large screen and are ready for use. The film can be applied to me silk either beforeor after the small screen iscut'from the large one.

Asshow'n at '42 and 44, framing elements of the type used in the embodiment of Fig. 1 can also be used in the method of this invention instead of conventional rectangular framing elements. The framing elements can be adapted to frame one character or can be large enough to accommodate a plurality. In manufacturing devices as shown in Fig. l, the screen is prepared by applying to the tightly-stretched silk the usual process film in the ordinary manner. That is, the letters or other charae-tershave been cut and peeled from the backing sheet of the process film, the'film is then adhered to the bottomof' the :screen, and the backing sheet is peeled off. Either'prior to the application of the film to the silk or subsequentithereto, the

framing elements

42 and 44 are cemented to the silk and thereafter the appropriate porflea of-thesilk is cut out from the large screen. If desired, the indicia alone can be cut from the screen and the' framing elements fastened afterwards to the cut-out piece of silk bearing the indicia.

While the preferred embodiment of the apparatus illustrated in Fig. 1 shows the section of silk in-a rectangular" form with two opposite ends provided with rigid framing elements, this arrangement is apparently only one specific example of the broad concept of the invention. The

of trapezoids, for example, are usable as well as polygons on curved surfaces to be printed.

with curvilinear sides. The primary requirements are that the rigid framing elements be of such dimensions and so located on the silk that the silk is uniformly stretched and yet the device is pliable enough to bend In general, this requires that at least 'one side of the silk section beflexible and free of any rigid'restraint. Thus, it is possible to use a U-shaped frame which can be, if desired, made of a base'framing'elementto which are rigidly fixed at right 0 angles two other framing elements. With such a U-shaped arrangement, the side of the silk polygon extending across the-top of the U is left free'of any rigid restraint. Similarly, the framing'elements can consist of two arms'- joined together pivotally or rigidly, to form aV-shaped 5 area spannedby the silk. When the framing elements are pivoted in a V arrangement, the device assumes the appearance of a collapsible fan. Whenthe fan-type construction is used, resilient means can be included for urging the two arms-apart or they can be omitted and the arms can be pushed'apart by the craftsman by hand' to keep the'silk taut. Devices with such V-shaped frames I particularly suited for printing on conical surfaces.

While, in the embodiment of Fig. 1, the resilient means for urging the framing elements apart to uniformly stretch a the silk is shown simply as a piece of spring wire engaged at both ends with single, centrally placed lugs on the framing elements, any other type of resilient means will serve the purpose of the invention so long as they main tain the silk in the proper taut condition. The resilient means can be connected to the framing elements to urge them apart at more than one location. For example, in

theembodiment of Fig. 1, two lugs could be used at each end of the silk section so long as the resultant force'was 45 stretched.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. the scope of the appended claims, the invention may be practiced otherwise thanas specifically described.

What is claimed is:

1. A device of the character described comprisinga' generally rectangular piece of silk'or the like of the type stantially thewidth of the rectangular silk fastened to the silk at one end thereof across its Width; a second similar rigid member fastened across the width of the silk atthe other end of the rectangle; a spring for maintaining the screen in tension by urging the two rigid members in opposite directions, including a first arm lying generally in a plane parallel to the plane of said-first rigid member a second arm similar to said first arm and lying generally in the plane of saidfirst arm, and an arcuate portion 5 joining said arms and urging them apart and lying generally in a'plane transverse to the plane formed by said silk and said rigid members and passing over said plane in a region substantially at least as remote from that center line of said rectangle which is transverse to said rigid 0 member as is the edge of said rectangle parallel to said center line; and means on said rigid member lying generally on said center line of said rectangle engaged by said 5 tension.

It is therefore to be-understood that within 2. The device of claim 1 wherein the free ends of said arms of said spring are provided with loops and said rigid members are provided with hook-like lugs adapted to be engaged by said loops, whereby said spring detachably engages said rigid members.

References Cited in the file of this patent UNITED STATES PATENTS 6 Shapiro Dec. 31, 1940 Auston Apr. 18, 1944 Cluzel Sept. 2, 1952 FOREIGN PATENTS France Dec. 5, 1903 OTHER REFERENCES Hiett et 21.: Silk-screen Process Production, 3rd ed.,

Pannier et a1. Oct. 20, 1936 10 1950. Blandford Press, Ltd. London, pages 181-183.