US3924343A

US3924343A - Expansible device for stretching material and method

Info

Publication number: US3924343A
Application number: US521589A
Authority: US
Inventors: Robert C Johnson
Original assignee: Metalogic Inc
Current assignee: Metalogic Inc
Priority date: 1974-11-07
Filing date: 1974-11-07
Publication date: 1975-12-09
Anticipated expiration: 1992-12-09

Abstract

A frame for stretching material secured thereto comprising elongated defining frame elements having mitered ends adapted for juxtapositioning with the confronting end of an adjacent frame element, with rotatable stud means coacting between adjacent frame elements coupling the latter together, and providing for movement of the coupled frame elements relative to one another upon rotation of the stud means for causing stretching of the material attached to the frame. A novel method of stretching material is also disclosed.

Description

United States Patent [191 Johnson Dec. 9, 1975 EXPANSIBLE DEVICE FOR STRETCHING MATERIAL AND METHOD Robert C. Johnson, Pittsburgh, Pa.

[73] Assignee: Metalogic, Inc., Chagrin Falls, Ohio [22] Filed: Nov. 7, 1974 [21] Appl. No.: 521,589

[75] Inventor:

[52] US. Cl 38/102.l; 160/374.1 [51] Int. Cl. D06C 3/08 [58] Field of Search 160/374, 374.1, 371, 372;

[56] References Cited UNITED STATES PATENTS 375,906 1/1888 Whitmore 160/374.l

587,882 8/1897 Tarnke.. 160/3741 1,916,023 6/1933 Shull 160/374! 3,448,551 6/1969 Heller 160/374.1 X

3,494,409 2/1970 Prechtl et al. l60/374.l X

FOREIGN PATENTS OR APPLICATIONS 128,867 6/1901 Germany l60/374.l

Primary Exam inerGeo. V. Larkin Attorney, Agent, or FirmBalclwin, Egan, Walling & Fetzer ABSTRACT A frame for stretching material secured thereto comprising elongated defining frame elements having mitered ends adapted for juxtapositioning with the confronting end of an adjacent frame element, with rotatable stud means coacting between adjacent frame elements coupling the latter together, and providing for movement of the coupled frame elements relative to one another upon rotation of the stud means for causing stretching of the material attached to the frame. A novel method of zstretching material is also disclosed.

9 Claims, 10 Drawing Figures US. Patent Dec. 9 1975 3,924,343

FIGB

HPI I Wm EXPANSIBLE DEVICE FOR STRETCHING MATERIAL AND METHOD This invention relates in general to a device and method for stretching material, such as for instance canvas or other fabric, for use, for instance, in painting, weaving, decorating or the like, and more particularly to an expansible frame wherein rotatable means are provided coacting between adjacent of the defining frame elements, coupling the frame elements together and providing for predetermined adjustment of the frame elements relative to one another upon predetermined rotation of the rotatable means. The device and associated method is adapted for use by inexperienced individuals and will consistently give uniform results.

BACKGROUND OF THE INVENTION Various methods and devices for providing a taut surface on fabric-like materials has heretofore been employed. One of these prior art methods includes using a generally rigid wood frame and merely pulling the fabric over the frame and then fastening it in place to the frame, such as for instance by tacks or stapling. Any subsequent stretching which occurs due to moisture or other causes with such prior art arrangement is generally not able to be effectively compensated for.

Another prior art method has been to provide a frame member which embodies wedge means adapted to be driven into each corner of the frame to put desired tension on fabric material secured to the frame. This method likewise does not permit effective further adjustment of the tension on the material after the tension has once been applied by the wedge means, and it is difficult to control the initial tension on the material primarily because of the inability to control the tension impact on each of the four corners of the frame equally.

Another prior art method has been to use a metallic type frame and secure fabric material thereto by means of a groove in the metallic frame. Tightening of the fabric material is accomplished by expanding each of the telescopic-like corners to cause a tension to be applied to the material. Generally due to the usual lightness of the metallic frame members, only moderate tightening can be achieved before twisting or bending of the frame occurs.

SUMMARY OF THE INVENTION The present invention provides a frame formed of defining frame elements movable relative to one another, together with readily rotatable adjusting means accessible from exteriorly of the frame, for causing expansion of the frame to thus cause stretching of attached material.

Accordingly, an object of the invention is to provide a novel device for stretching material secured thereto, for use, for instance, in painting, weaving, decorating or the like.

A further object of the invention is to provide a device of the aforementioned type comprised of a plurality of frame elements having mitered ends adapted for juxtapositioning with the confronting end of an adjacent frame element, with the confronting ends having apertures therethrough disposed at generally right angles to the mitered face of the respective element, and with rotatable means including bushing means disposed in the apertures and stud means extending into the apertures in the adjacent elements and coacting in force applying relation with the bushing means, for causing relative expansion and contraction movement between the adjacentframe elements upon rotation of the stud means, thereby providing for adjustment stretching of material attached to the frame.

A still further object of the invention is to provide a device of the aforementioned type wherein the frame elements may be formed of wood for convenient attachment of the material to the frame and providing an arrangement which is economical to make and marketable in unassembled kit form, and wherein the device effectively and expeditiously provides for precise stretching of the material which will give uniform results every time irrespective of the use by inexperienced persons.

A still further object of the invention is to provide a device of the aforementioned type wherein the frame includes corner means for forming the comers for the frame irrespective of the expansion or contraction of the frame elements relative to one another, with the corner means imparting considerable strength and stability to the frame.

'A still further object of the invention is to provide a novel method for stretching material for use for instance in painting, weaving, decorating or the like.

Other objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a bottom plan view of a frame for stretching material constructed in accordance with the present invention, and illustrating a piece of material secured thereto;

FIG. 2 is an enlarged, fragmentary, sectional view of one of the corners of the frame of FIG. 1 with the rotatable means for causing expansion and retraction of the frame elements relative to one another;

FIG. 3 is a view similar to FIG. 2 except that the retatable means has been shown actuated so as to close the frame elements relative to one another into engaged relation at their mitered faces;

FIG. 4 is a top or frontal plan view of the frame of FIG. 1, with certain of the adjustable rotatable means having been actuated to cause movement of the respective frame elements relative to one another;

FIG. 5 is an enlarged, fragmentary, sectional view of one of the ends of one of the frame elements showing the aperture means therein disposed generally perpendicular to the plane of the mitered face of the element;

FIG. 6 is a top plan view of the mitered end of the frame element illustrated in FIG. 5;

FIG. 7 is a plan view of a piece of material which is adapted for securement to the expansible frame and illustrating a particular arrangement including an opening in the material, for insertion of a tool therethrough;

FIG. 8 is an enlarged, side elevational view of one of the corner members of the expansible frame assembly;

FIG. 9 is an end view taken from the bottom of FIG.

FIG. 10 is an elevational, partially sectioned, illustration of a tool which may be conveniently utilized in conjunction with the expansible frame, for adjusting the rotatable stud means thereof in the operation of stretching material on the frame.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now again to the drawings, there is shown an expansible and retractable material stretching device comprising a polygonal shaped frame which includes defining side elements 12 preferably formed of. wood or some other suitable material to which stretchable material, such as fabric 14, can be expeditiously fastened. In the embodiment illustrated, fastening of the fabric 14 to the frame 10 is accomplished by means of staples 16 disposed along the peripheral edge of the piece of fabric, and holding the latter in mounted attached condition on the frame 10. While staples have been illustrated, it will be understood that other suitable fastening means such as for instance adhesive, can be used to fasten material to the frame. If the frame is for weaving, upstanding pins can comprise the fastening means.

The side elements 12 are preferably of sufficient cross sectional area to provide substantial stiffness to the elements, with the elements having mitered ends defining end faces 18, which mitered faces are adapted for juxtapositioning with a confronting mitered face of the adjacent frame element, and as shown for instance in FIG. 3. Aperture means 20 is provided through each of the ends and extends generally perpendicular to the plane of the respective mitered face. Such aperture means extends from exteriorly of the respective frame element through the respective mitered face, and comprises, in the embodiment illustrated, an enlarged diameter opening 22, and a smaller diameter opening 24, axially aligned with opening 22 thereby providing shoulder 26 for a purpose to be hereinafter described.

Rotatable means 28 (FIGS. 2 and 3) are provided coacting between adjacent frame elements and coupling the latter together. Rotatable means 28 comprises in the embodiment illustrated, an elongated stud 30 which is threaded adjacent opposite ends thereof as at 30a, 30b, and preferably having a central nonthreaded knurled section 300, adapted for rotation by the fingers of an individual during assembly of the frame elements 12.

Stud 30 coacts in force applying relation with threaded

bushings

32,32a (FIGS. 2 and 3) positioned in the respective aperture means 20 in the respective frame element 12. Thread 30a and associated internally threaded bushing 32 can be for instance a righthand thread and the other end of the stud and associated thread internally threaded bushing 32a can be a left-hand thread, so that rotation of the stud 30 in one rotary direction causes movement of the frame elements toward one another. Rotation of the rotary stud 30 in the opposite rotary direction causes relative movement of the frame elements 12 away from one another.

Bushings

32,32a are of a lesser length than the length of the respective opening 22 in which they are disposed in non-movable relation, with such bushings engaging the aforementioned shoulder 26 in the associated aperture means thus positioning the bushing in the aperture means. A portion of the exterior of each of the bushings may be roughened, as by knurling and as at 33, to prevent rotation when in the respective opening 22.

At least one end of the stud 30 is provided with preferably a slot 36 (FIG. 2) adapted to receive a tool from exteriorly of the frame, for causing rotation of the stud and thus relative movem ent between the associated 4 frame elements 12 as will be hereinafter described in detail.

Each end of each frame element 12 preferably embodies a slot 38 (FIGS. 2 and 6) which is adapted to receive therein a portion of a corner member 40 (FIGS. 8 and 9) and more particularly the centrally located web 42 thereof, for forming a positive corner for the frame irrespective of the expansion of the frame elements relative to one another during stretching of the material.

Each of the comer members 40, in the embodiment illustrated, comprises flange portions 44 disposed in generally V-shaped configuration (FIG. 8) and connected by central web 42. Flange portions 44 are adapted to be received in recessed area 46 of the adjacent frame elements, so that such flange portions provide a generally flush continuation of the outer side edge 47 of the respective frame element. Corner portions 40 can be made of any suitable material, such as for instance, plastic or metal, such as for instance aluminum, and add substantial strength and stability to the frame regardless of the degree of expansion and/or retraction of the frame elements relative to one another.

As can be best seen in FIG. 7, the piece of material 14 is preferably so configured at its corners that a tab section 50 thereon will extend over the respective corner portion and be overlapped by the respective side portion 52 of the adjacent peripheral edge of the fabric. Since the tab 50 is not anchored down by staples or the like, the frame elements can expand, tensioning the fabric attached to the frame during adjustment of the rotatable means 28. The fabric section 14 is preferably provided with an opening 56 therein which is adapted for alignment with the aperture means 20 in the respective frame element and in generally overlying relation with respect to the slot 36 in the associated stud 30, so that a tool can be inserted from exteriorly of the frame 10, through the fabric into the aperture means 20, for engaging with the slot in the stud during rotation of the latter, thus applying stretching force to the fabric attached to the frame.

It will be seen that merely positioning the fabric with its dotted or prelaid out aligning lines 58 thereon, on the frame, will insure proper positioning of the opening 56 with respect to the aperture means 20, to provide for proper alignment of opening 56 in the material with the aperture means in the associated frame elements. Lines 58 corresponds to the side edges of the respective frame element.

Although a conventional screwdriver may be utilized, a tool member 60 may be provided for insertion into the aperture means, and into engagement with the stud 30, for rotating the latter. Such tool in the embodiment illustrated comprises a handle portion 62 having a shank portion 64 rigidly connected thereto, and with the shank portion having a blade 66 at its distal end, which blade 66 is adapted to be received in the aforementioned slot 36 in the respective stud 30, to provide for rotating the latter.

A collar member 68 is axially movable on the shank portion 64 and is adapted for engagement with an abutment 70 on the shank portion and is urged toward the abutment by means of a compression spring 72.

It will be understood that the blade and shank portion are adapted to be received into the bushing opening in the respective bushing, so that the blade 66 can engage the slot 36 in the stud 30. Movement of the shank portion 64 and associated blade 66 into the bushing will cause engagement of the collar 68 against the confronting end of the bushing, thereby causing compression of the compression spring 72. Upon release of the force applied to the handle, the spring 72 will cause retraction of the shank portion 64 and associated blade 66 from coaction with the slot 36 in the confronting end of the stud 30.

The stretching device of the invention may be conveniently provided in kit form, so that the parts can be readily assembled by anyone who may have no particular skill in utilizing the device, and which can be readily used by anyone with no particular skill and training, for stretching material for use for instance in painting, weaving, decorating and the like. When the kit is opened, the assembler can take the adjusting stud at the knurled midsection and rotate it so as to engage in threaded coaction with the respective metal bushing in a pair of confronting frame sections. This rotation will cause the two frame sections 12 to move toward each other. After the frame members 12 have been moved closer together by a few turns of the stud 30 the assembler can insert a screwdriver or the tool 60 into the aperture in the frame member which contains the slotted end 36 of the stud, for causing rotation of the stud until no further rotation is possible, or in other words, when the mitered faces of the two frame members abut tightly together, as shown for instance in FIG. 3. Such assembly procedure can then be repeated for the other unassembled sections of the frame which can then be aligned as shown for instance in FIG. 4 and connected by means of the associated rotatable means 28.

Prior to attaching the fabric material to the frame the comer tabs or portions 40 can be inserted into each comer. Such comer portions act as a stiffener to give strength to the structure and resist any tendency of the frame sections to twist during the stretching process. The corners 40 also act to maintain sharp right angle corners which would otherwise be lost as the stretching process opened gaps between adjacent frame members. As aforementioned, the material tabs 50 on fabric 14 aids to maintain corner portions 40 in place.

In assembling the fabric material 14 to the frame 10, the assembler may grasp the fabric material at the center or any side and fold the material over the edge of the adjacent frame element 12. Shoulder 74 (FIG. 6) on the back side of the respective frame element aids in securing the fabric evenly to the frame. The outermost periphery of the fabric can be expeditiously aligned along the back side of the associated frame element by matching it with a mark on the frame element. The material positioning process can then be repeated on the opposite side of the frame, and then again on the two remaining frame elements. The assembler can then attach staples 0r tacks progressively and alternately outwardly from the first attaching point, with the fasteners disposed along lines running parallel to the respective peripheral edge of the material and as shown in (FIG.

1). The assembler can then proceed with stretching of the fabric material if he is using tacks or staples, or if he has used an adhesive on the fabric, time must expire for the curing of the adhesive, prior to stretching the fabric. It will be seen therefore that assembly of the fabric to the frame becomes a simple matter.

After the unstretched material has been secured to the assembled frame the latter preferably being in the closed condition (FIG. 3), the process of stretching may begin. The assembler may insert a screwdriver or the tool 60 through any one of the clearly marked slits 56 cut in the fabric material, and rotate the tool one full turn in a direction so that relative expansion movement between the adjacent frame elements occurs. Such procedure will preferably be repeated successively at each corner until the fabric material begins to tighten up and will continue until the desired tautness of the material is accomplished. The assembler can easily check the uniformity of tautness by measuring the width of the gap between the adjacent frame elements 12. If it is not the same at each comer, he knows that the fabric materialis under uneven tension, and this may be easily corrected by readjusting the rotatable means 28 at any corner. With the use of the device hereinabove described, adjustments can be readily made at any time, and even after the assembly is completed, and after the work on the material is completed.

From the foregoing description and accompanying drawings, it will be seen that the invention provides a novel device for stretching of fabric material, for use for instance in painting, weaving, decorating or the like, and wherein the device comprises a frame including elongated defining frame elements movable relative to one another, with rotatable means coacting between adjacent of the frame elements and coupling the latter together. Predetermined adjustment of the rotatable means causes expansion of the frame, for causing stretching of the material. The invention also provides a novel arrangement of fabric material stretching frame wherein the rotatable adjustment means includes right and left hand threads on a rotatable stud coacting in force applying relation to bushings embedded in the associated frame element to cause relative movement therebetween. The invention also provides a novel method of stretching a material on a frame, and one wherein the stretching process can be precisely and effectively controlled and accomplished.

The terms and expressions which have been used are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of any of the features shown, or described, and it is recognized that various modifications are possible within the scope of the invention claimed.

What is claimed is:

1. A frame for stretching material secured thereto, said frame comprising elongated defining frame elements movable relative to one another, and rotatable means coacting between adjacent of said frame elements coupling the latter together, predetermined adjustment of said rotatable means causing expansion of said frame, for causing stretching of the material, and wherein said frame elements have mitered end faces adapted for juxtapositioning with the confronting mitered face of an adjacent element, each of said frame elements having an aperture therethrough disposed substantially at right angles to the respective mitered face and receiving therein in rotatable relation said rotatable means, each of said elements comprising a slot therein at the distal end thereof and receiving therein relatively movable corner means forming a comer for the frame irrespective of the expansion of the frame elements relative to one another during stretching of the material, said corner means imparting strength and stability to the frame regardless of the degree of expansion and retraction and the frame elements relative to one another.

2. A frame in accordance with claim 1 wherein said rotatable means includes bushing means disposed in said apertures and stud means extending into said apertures in said adjacent elements and coacting in force applying relation to said bushing means for causing relative movement between said adjacent frame elements upon rotation of said stud means, and means on said rotatable means accessible from exteriorly of the respective frame element for causing rotation of said stud means and thus adjustment and relative movement between the confronting ends of adjacent frame elements.

3. A frame in accordance with claim 2 wherein said apertures each comprises a first opening extending generally perpendicular to the plane of said mitered face of the respective frame element and an axially aligned second opening greater in diameter than said first opening, extending from exteriorly of the frame element and communicating with the first mentioned opening, said second mentioned opening being adapted to receive therein the respective bushing means, while both said first and second mentioned openings are adapted to receive in generally axial relation said stud means.

4. A frame in accordance with claim 1 wherein said frame elements are formed of wood for convenient attachment of the material to the frame, and as for instance, by means of staples applied to the frame elements and material prior to said predetermined adjustment of said rotatable means for stretching the material.

5. A frame in accordance with claim 1 wherein said rotatable means comprises an elongated threaded stud threaded on opposite ends thereof, means on an end of said stud adapted for engagement with a tool for causing rotation of the stud, and internally threaded, nonrotatable bushing members disposed in said apertures and coacting in threaded relation with the respective threaded end of said stud, said bushing at one of said threaded ends comprising a right hand internal thread while the bushing at the other of the threaded ends comprises a left hand internal thread, formed complementary to the threads on said stud, so that rotation of stud in one rotary direction causes adjacent frame elements to move away from one another while rotation of the stud in the opposite rotary direction causes the adjacent frame elements to be drawn toward one another, said means on one end of said stud for rotating said stud being accessible from exteriorly of at least one of said adjacent frame elements.

6. A frame in accordance with claim 1 wherein said corner means comprises a bracket member having a central web adapted to be received in the respective slot of the adjacent frame sections and flanges projecting laterally from said central web, said flanges defining the respective corner of the frame during relative movement between adjacent frame elements of the frame.

7. A frame in accordance with claim 1 wherein said rotatable means comprises a threaded stud member threaded at opposite ends thereof and having an intermediate non-threaded section separating the threaded section, one end comprising a right hand thread and the other end of said threaded member comprising a left hand thread, and means on at least one end of said threaded member for receiving a tool for providing for tool rotation of said threaded member relative to said frame elements.

8. A frame for stretching materials secured thereto, said frame comprising elongated defining frame elements movable relative to one another, and rotatable means coacting between adjacent of said frame elements coupling the latter together, predetermined adjustment of said rotatable means causing expansion of said frame for causing stretching of the material, and including comer means coacting between respective adjacent frame elements and movable relative to the latter for maintaining stability of the comers of the frame irrespective of adjustment movement of the frame elements relative to one another upon said predetermined rotation of said rotatable means.

9. In a method for stretching material including providing an expansible and retractable frame comprising elongated defining frame elements movably coupled to one another by plural force applying rotatable means, removably securing a piece of stretchable material to the frame elements along the latter, at least certain of said frame elements having a mitered end defining an end face adapted for juxtapositioning with the confronting end face of an adjacent frame element, with said mitered end having an aperture therethrough disposed at generally right angles to the mitered end face, said material having an opening therethrough, and aligning said opening in the material with said aperture for actuation of said rotatable means from exteriorly of said frame and through said material after securing said material to said frame, and inserting a hand tool through said aligned opening and aperture and rotating said rotatable means from exteriorly of said frame for actuation of said rotatable means to cause expansion of the frame.

Claims

1. A frame for stretching material secured thereto, said frame comprising elongated defining frame elements movable relative to one another, and rotatable means coacting between adjacent of said frame elements coupling the latter together, predetermined adjustment of said rotatable means causing expansion of said frame, for causing stretching of the material, and wherein said frame elements have mitered end faces adapted for juxtapositioning with the confronting mitered face of an adjacent element, each of said frame elements having an aperture therethrough disposed substantially at right angles to the respective mitered face and receiving therein in rotatable relation said rotatable means, each of said elements comprising a slot therein at the distal end thereof and receiving therein relatively movable corner means forming a corner for the frame irrespective of the expansion of the frame elements relative to one another during stretching of the material, said corner means imparting strength and stability to the frame regardless of the degree of expansion and retraction and the frame elements relative to one another.

5. A frame in accordance with claim 1 wherein said rotatable means comprises an elongated threaded stud threaded on opposite ends thereof, means on an end of said stud adapted for engagement with a tool for causing rotation of the stud, and internally threaded, non-rotatable bushing members disposed in said apertures and coacting in threaded relation with the respective threaded end of said stud, said bushing at one of said threaded ends comprising a right hand internal thread while the bushing at the other of the threaded ends comprises a left hand internal thread, formed complementary to the threads on said stud, so that rotation of stud in one rotary direction causes adjacent frame elements to move away from one another while rotation of the stud in the opposite rotary direction causes the adjacent frame elements to be drawn toward one another, said means on one end of said stud for rotating said stud being accessible from exteriorly of at least one of sAid adjacent frame elements.

8. A frame for stretching materials secured thereto, said frame comprising elongated defining frame elements movable relative to one another, and rotatable means coacting between adjacent of said frame elements coupling the latter together, predetermined adjustment of said rotatable means causing expansion of said frame for causing stretching of the material, and including corner means coacting between respective adjacent frame elements and movable relative to the latter for maintaining stability of the corners of the frame irrespective of adjustment movement of the frame elements relative to one another upon said predetermined rotation of said rotatable means.