WO1997006957A1

WO1997006957A1 - Stretching frame for use in silkscreening

Info

Publication number: WO1997006957A1
Application number: PCT/US1995/010548
Authority: WO
Inventors: James D. Larson
Original assignee: Larson James D
Priority date: 1993-11-03
Filing date: 1995-08-18
Publication date: 1997-02-27
Also published as: US5443003A

Abstract

This invention is a longitudinal strip (92) for use in silkscreening, adapted to have attached thereto the screening fabric (F), the strip including an interlocking mechanism (88) such that when the screen is under tension the strip (92) is securely fastened to the side frame element (6) of a retentive silk screen frame. The strip (92) may be preformed and the screen (F) cut and attached thereto to reflect and accommodate the flexure of the frame when the tension, appropriate to the material, is applied thereto.

Description

STRETCHING FRAME FOR USE IN SILKSCREENING

Technical Field

This invention relates to a silk screen stretching frame and, more particularly, to a stretching frame which allows the temporary removal and replacement of the screen fabric. An alternate approach is to provide a precut screen fabric including an attached flexible edge, which compensates for the flexure of the frame and the fabric, for removable attachment to the frame.

Background of the Invention

Historically, silk screening has been used for inexpensive decoration of materials, including clothing such as Tee shirts and the like, since a selected pattern can be reproduced with minimal labor and expense. More recently, designer clothes have also been silkscreened.

One of the drawbacks of silk screening lies in the fact that if a particular pattern was believed to be of the type which would be in demand for an extended period, then the screen would be stored, such that it could be reused without having to be replaced. This, of course, reguired utilization of a higher quality screen so that it could withstand the multiple usage, but beyond this concern a difficulty existed in the storage of the screen itself. Since the screen is stretched on a frame so that it can reproduce with high quality and integrity, it cannot be easily removed and replaced. Because of the difficulty in removing and replacing, these screens have historically been stored on the frame, which requires additional storage space, since the frame is bulky. This storage method further required that the person doing the screening carry an inventory of frames, since, obviously, a frame that is in storage cannot be used for another screening job until the initial screen has been removed and replaced.

Over the years, a large variety of means have been used for stretching fabric or the like, and these are illustrated by U.S. Patent No. 484,137 granted to Caufield, October 11, 1892, which discloses a device for keeping leather under tension during the curing process and includes means for adjusting the tension.

U.S. Patent No. 673,197 granted to Collins, April 30, 1901, discloses a device for stretching a garment.

U.S. Patent No. 721,749 granted to Sanders, March 30, 1903, discloses a device for stretching trousers, which includes a means for adjusting the stretching frame. U.S. Patent No. 886,400 discloses a shade roller which is of interest in the present invention, because it likewise discloses a means for securing the shade to the roller.

U.S. Patent No. 1,546,400 granted to Nichols, July 21, 1925, discloses a molding cloth stretcher wherein the cloth is secured to frame rollers by outwardly extending pins or the like and then the fabric is placed under tension.

U.S. Patent No. 1,711,670 granted to Brennan, May 7, 1929, discloses a method for securing a screen to a framework.

U.S. Patent No. 3,601,902 granted to Dubbs, August 31, 1971, discloses a silk screen stretching frame and the method of attaching the screen to the frame, as well as increasing the tension thereon.

U.S. Patent No. 3,908,293 granted to Newman, September 30, 1975, discloses a silk screen frame, as well as a method of attaching the screen and adjusting the tension. U.S. Patent No. 4,860,467 granted to Larson,

August 29, 1989, discloses a silk screen frame, the method of attaching the screen and the means for adjusting the tension on the screen.

Disclosure of the Invention

The present invention contemplates a silk screen frame device wherein the frame elements each include a removable strip to which the screen is attached. The strip is secured to the frame member in such a manner that adequate tension may be applied to the fabric, and further each of the frame elements includes an indexing means wherein the screen may be easily removed and replaced.

With the above-noted prior art and problems in mind, it is an object of the present invention to provide a silk screen frame wherein the screen may be easily removed from the frame and stored.

It is another object of the present invention to provide a silk screen frame including removable strips to which the silk screen is attached and wherein such strips are removable but provide reliable support during the tensioning and screening process.

A still further object of the present invention is to provide a silk screen frame wherein the tensioning upon the silk screen may be done from the exterior of the frame, permitting the use of automatic tensioning devices.

A further object of the present invention is to provide a precut silkscreen including a semi-rigid edge secured thereto wherein the cut screen and the edge accommodate the quality of the screen and the deflection of the frame when the screen is placed under the appro¬ priate tension as well as the necessary presoftening of the corners.

Yet another object of the present invention is to provide a method of preparing a silkscreen for ready use comprising the steps of determining the frame size, determining the fabric to be used, placing the fabric over a mold/template containing edge members which have been preformed to compensate for the deflection of the frame when placed under tension, securing the fabric to the strips, and cutting the fabric to the shape of the strips, whereby the strips may be removably placed into grooves in the frame and the screen placed under tension, resulting in a predictable screen surface which may be stored without the frame.

Brief Description of the Drawings Figure 1 is a pictorial representation of the present inventive framework from the back side.

Figure 2 is an enlarged view of the corner of the framework of Figure 1.

Figure 3 is a cross-sectional view of one species of the side element of the present inventive frame.

Figure 4 is a sectional view through another embodiment of the present invention.

Figure 5 is an isometric view of a tensioning member with the securing strip exploded away for clarity.

Figure 6 is a sectional view through the tensioning member of Figure 5.

Figure 7 is a sectional view through the corner of the inventive frame illustrating the means whereby the tension may be adjusted from a position exterior to the corner.

Figure 8 is a plan view of the template or mold used in preparing the ready-to-use screen. Figure 9 is a section along 9-9 of Figure 8 and including an exploded spline or edge element.

Figure 10 is an exploded view showing the fabric secured to the spline or edge prior to insertion into a protective cover. Figure 11 is an exploded view of the fabric with the protective cover ready to be placed in one element of the frame. Figure 12 is a plan view of the precut fabric with the spline and protective cover secured thereto.

Best Mode for Carrying Out the Invention As seen in Figure 1, the present invention includes a silk screen frame including four corner elements 2 interconnected by tensioning rods or tubes 4 having mounted thereon removable strips 6 to which the screen 8 is secured. Use of the strips as explained hereinafter permit the removal and storage of screens while freeing up the frames for additional use.

Reference is now had to Figure 2, which is an enlargement of the corner section of Figure 1, and it can be seen that tensioning rods 4 which are in the configuration of hollow cylinders have the strips 6 secured thereto by means of radially outwardly extending projections 10, which slip into complementary holes in the strips 6. The screen fabric is adhesively secured to the strips 6. As will be explained hereinafter, the axial lines 12 on the roller 4 are used during the retensioning of the screen when it is replaced for reuse and are used in conjunction with the marking 14 on the corner 2. The means for securing the frame elements 4 such that the screen is in tension as well as creating the tension are illustrated with a jam nut 16 and a hex head 18 for use in manual turning of the tube 4 with a standard wrench to create tension on the screen secured thereto.

Reference is had to Figure 3, which is a cross-section through the frame tube 4 and depicts the alignment grooves 12 as well as internal reinforcing ribs 20. A groove or slot 22 is adapted to receive a complementarily shaped strip 6, to which the fabric 8 is secured by adhesive. It is to be noted that the groove 22 includes a sloping front portion 24, a flat bottom 26 and a forwardly projecting lip 28 such that the strip 6, which includes complementarily shaped foot member 30 and flanges 34, 36, can be slid into the slot 22 and then held in position by the tension placed upon the screen itself.

Reference is now had to Figure 4, wherein a strip 6 is secured to a tube 4 and has a generally identical configuration; however, the fabric 8 is held in position by means of a groove 38 formed in the strip 6, into which an elastic compressible member 40 is snapped. Reference is now had to Figures 5 and 6, wherein the tube 4 includes a pair of diametrically opposed, somewhat flattened surfaces 42. Surfaces 42 lie within the circumference of the tube such that when the strip 6, having a downwardly projecting foot 44 complementary to slot 46 in the bottom of the flattened portion 42 of the tube 4, is in position, the fabric is presented with a substantially smooth, cylindrical surface. It is to be noted that a steel tube 48 is seen in the interior of the tube 4 in Figure 6. The steel tube is used in large frames to reinforce the aluminum tube and reduce flexure.

As seen in Figure 7, a cap screw 50 may be substituted for hex head 18 in Figure 2 to accommodate exterior tensioning means such as automatic tensioning. An aluminum plug 52 having an all-thread 54 seized therein is placed in the ends of the tensioning members 4. Loosening jam nut 56 allows adjustment of the screen tension by rotation of bolt 50. A standard hex head bolt 58 is used at the opposite end of each tube for locking purposes.

Although the inventive strip is shown in conjunction with a tube manufactured therefor, it is to be understood that with appropriate modifications it could be used with any retensionable frame having an axial slot along the exterior surface.

Reference is now had to Figure 8, wherein a plan view of the template or mold is shown, it being understood that each frame size would have its own template or mold for the particular screen material to be used. As seen in this view, the template or mold comprises a solid piece of material 80 having an outer edge 82 and an inner surface 84, wherein the two surfaces 82, 84 are at different elevations as explained hereinafter. Separating the two surfaces 82, 84 is a groove 86 which is configured to represent the deflection of the frame when the particular fabric is put under tension as well as accommodating the corners.

Referring now to Figure 9, a section along lines 9-9 of Figure 8, the outer surface 82 can be seen to be at a lower elevation than the inner surface 84 and a spline or edge member 88 having a double-sided tape 90 is about to be placed within the groove 86. The tape secures the fabric to the splines.

As seen in Figure 10, the silk screen fabric F with the spline 88 secured thereto is then inserted into an elongated protective shield 92 having a lower surface 94 including a lip 96, a rearward surface 98 substantially perpendicular to the bottom surface 94, and a wider, forwardly extending curved shield portion 100 including water and solvent traps 102. Prior to placing the fabric and an attached spline into the shield, an adhesive is placed in the shield such as the binding is permanent. Figure 9 discloses how the fabric edge with the fabric secured thereto is removably inserted into a frame member 6, which includes a groove having outwardly and inwardly tapered sides to wedge the edges and hold the material in place during the tensioning of the device.

As seen in Figure 12, the fabric with the edges secured thereto is shown such as it would appear prior to the sale and during storage. As seen in this view, when removed from the frame itself, the edge and the fabric assumes the position that it would take when under the pressures that are necessary to hold the fabric steady and accomplish the silk screening steps.

Although preferred embodiments of the invention have been disclosed herein for illustration, it should be understood that various changes, modifications and substitutions may be incorporated in such embodiment without departing from the spirit of the invention, which is defined by the claims which follow:

What is claimed is:

Claims

1. A stretching frame for use in the silkscreen industry, comprising: four side members mounted in a rectangular pattern, interconnected by corner members, whereby at least one of the side members is mounted for rotation; a removable strip member for each of the side members, whereby the strip member is secured to the respective side member and the screen is secured to the strip such that the screen, still attached to the strips, may be removed from the frame, stored and replaced upon the frame.

2. The frame as in claim 1, wherein the side members are cylindrical and include index means allowing the screen to be accurately replaced.

3. A frame as in claim 1, wherein the tension may be adjusted from a position exterior to the frame.

4. A strip of rigid material comprising an outer surface, including means for securement of an edge of a silkscreen fabric and an inner irregular surface, said inner irregular surface including at least one outwardly projecting ridge, said ridge being at an angle such that when the strip is placed upon the tube of a retensioning frame and pressure is applied to the screen fabric, the strip is releasably locked to the tube.

5. Means for securing a silk screen fabric to a silk screen frame wherein it is possible to adjust the screen tension by rotating the side frame elements about their longitudinal axis comprising a strip which is removably attached to each of the side frame elements, means to attach the screen fabric to the strips and means whereby the tensioning of the fabric secures the strips in place.

6. A precut and edged piece of fabric for silk screening, wherein the fabric is contoured to accommodate the size of the frame, the deflection of the frame when the fabric secured thereto is placed under tension, and wherein the edge is permanently affixed to the contoured fabric and capable of being removably secured to a silk screen frame, enabling the edged screen to be removed, stored and reused.

7. The silk screening fabric of claim 6, wherein the presoftening of the corners of the fabric is accommodated.

8. A method of preparing a fabric for a silk screen frame, comprising the steps of: a) placing a spline strip in a configuration which compensates for the size of the frame to be used and the deflection of the frame which will occur when the fabric which has been secured to the frame is placed under the maximum tension for which it is designed; b) adhesively securing the strips to the fabric; c) cutting the fabric along the outside edge of the spline strip, and; d) securing the spline strips to an edge piece which is designed to be removably secured to the frame.