GB2230950A - Picture frames - Google Patents

Abstract

A frame for a picture, poster or the like is spring-loaded 26 to extend in at least one direction to apply slight tension to the item 28 held by the frame and to take account of expansion and contraction of the item with variations in for example temperature and humidity. Means may also be provided to apply a tension in the sideways direction. <IMAGE>

Description

FRAMES This invention relates to frames for items of sheet material, such as pictures, posters, maps, screens, wall coverings and textiles. This application is supplemental to United Kingdom Patent Application No 8830430.8 filed 30 December 1988 and European Patent Application No 88312386.1 filed 29 December 1988, the contents of which are incorporated herein by reference as if set out in full below.

In order to permit sheet material, particularly paper, held by a frame to expand and contract as a result of, for example, variations in ambient temperature or humidity, the frame of the earlier application has two rail members to which the sheet material is attached and two telescopic frame members which are resiliently biassed to extend and which act between the rail members to hold the sheet material gently in tension.

In the frames specifically described in the earlier applications, there is a joint between each rail member and each frame member which permits the members to pivot not only about an axis perpendicular to the plane of the frame, but also at least about an axis generally parallel to the rail member. This latter pivotal action is not required in order that the frame can allow expansion and contraction of the sheet material and will mean that the frame can twist out of a generally planar configuration, and therefore steps are taken to inhibit such a twisting effect by incorporating a cross-member or by a spline arrangement at the joints and at the telescoping parts of the frame members.The former pivotal action is also not required if the apparatus is to be designed merely to cope with uniform expansion and contraction of the sheet material, or if some degree of flexibility is provided in the rail and/or frame members.

The present invention is concerned more particularly with a frame for an item of sheet material, comprising: a set of frame members connected together to form the frame with an opposite pair of the members being movable towards and away from each other; means to attach an item of sheet material between said opposite pair of frame members so that the frame members frame the item; and means for resiliently biassing said opposite pair of frame members apart so as to tension the item.

In accordance with said one aspect of the present invention, the frame is as defined in the preceding paragraph, but is not as disclosed in the previous application.

In accordance with another aspect of the present invention, each connection of the frame members is such as to inhibit any substantial pivotal movement of the respective members relative to each other about axes lying in the plane of the frame. At least one of the connections of the members may include means to permit pivoting of the respective members about an axis substantially perpendicular to the plane of the frame. Also, at least one of the connections of the frame members may include means to inhibit any substantial pivotal movement of the respective frame members.

There follows a description by way of example of specific embodiments of the present invention with reference to the accompanying drawings, in which: Figure 1 is an isometric view of one embodiment of a frame according to the present invention; Figure 2 is a more detailed exploded view on a larger scale of a corner joint and part of a stile member employed in the frame of figure 1; Figure 3 is a more detailed view of an end of a rail member and a clamp for holding an item of sheet material, employed in the frame of figure 1; Figure 4 is a modified embodiment of a frame according to the present invention; and Figure 5 is an exploded perspective view of a modified form of corner joint.

Referring to figure 1, the frame comprises four frame members, namely an upper rail 10, a lower rail 12, a left stile 14, and a right stile 16 connected by four corner joints 18. Each of the left and right stiles 14, 16 includes an upper tubular portion 20, a lower tubular portion 22, a pin 24 extending between and within the upper and lower tubular portions 20, 22 so that the left and right stiles 14, 16 are telescopically extendable, and a compression coil spring 26 encircling the pin 24 and bearing between the upper and lower tubular portions 20, 22 to urge them in a direction to extend the length of the left or right stile 14, 16.Preferably, the pin 24 and the upper and lower tubular portions 20, 22 have inter-engaging splines, as described- with reference to figure 6 of the previous applications, in order to prevent rotation of the tubular portions 20, 22 relative to each other about their own axes.

A poster 28 or other item to be displayed is attached to the upper and lower rails 10, 12, for example in the manner described with reference to figure 4 or figure 5 of the previous application or in the manner described in United Kingdom Patent Application No 8903883.0, the content of which is incorporated herein by reference as if set out in full below.

Thus, the poster 28 is held under gentle tension in the vertical direction by virtue of the action of the springs 26 on the stiles 20. Also, depending upon the method of attaching the top and bottom of the poster to the upper and lower rails 10, 12, tensioning in the horizontal direction may also be provided.

Referring now to figures 2 and 3 which illustrate the form of corner connection provided in the arrangement of figure 1, the corner joint 18 comprises a ball shaped element 30, from which an integral spigot 32 projects. The spigot 32 engages in the end of the stile 14,16 and has a key-way (not shown) which co-operates with an integral spline 34 extending longitudinally and internally of the stile 14,16, to prevent rotation of the corner joint 18 relative to the stile about the axis of the stile. The spigot 32 projects a sufficient distance into the stile and is a sufficiently tight push fit therein to prevent any substantial wobbling of the corner joint relative to the end of the stile.

As shown in figure 3, each end of each rail 10/12 is fitted with a clamp 36 to grip the corner of the poster in exactly the same way as described in the earlier applications and to exert a side-ways tension to the poster. A spigot 38 projects from the end of the rail 10/12 and is a sufficiently tight fit into a co-operating recess 60 in the ball 30 of the corner joint 18 to prevent any substantial wobbling of the corner joint relative to the end of the rail 10/12.

The recess 60 is formed with a pair of splines 62 which engage key-ways 64 in the spigot 38 to prevent rotation of the corner joint 18 relative to the rail 10/12 about the axis of the rail 10/12.

It will be appreciated from the above that the spigots 32,38 prevent any substantial pivoting of the rails and stiles at the corners of the frame, although a small degree of movement may be provided, and the splines 34,62 and key-ways 64 resist twisting of the frame out of its own plane.

In order to assemble the frame and a poster, the rails and stiles are cut if required to length, and the poster is attached to the rails. The corner joints are then attached to the stiles and to one of the rails. The stiles are then manually compressed longitudinally and the other corner connections are completed. When the stiles are subsequently released, they expand to hold the poster in tension.

Referring now to figure 4, there is shown a modification to the frame described above with reference to figure 1, in which like elements are designated by like reference numerals. In the case of the arrangement of figure 4, the upper and lower rails 10, 12 are each formed of a pair of sections 38 telescopically joined by a pin 40, with a compression coil spring 42 acting between the pairs of rail sections 38 to urge them apart and thus extend the frame in the horizontal direction. The action is therefore similar to that provided by the stiles 14, 16. The poster is fixed at the regions denoted by reference numeral 44 to the outer ends of the rail portions 38 by the devices such as those referred to above in the earlier applications. Thus, the frame of figure 4 provides gentle stretching of the poster 28 in the sideways direction in addition to the vertical direction.

Figure 5 shows a modified corner joint which may be used in the arrangement of figure 1 or figure 4 as an alternative for the corner joint shown in figures 2 and 3. The corner joint of figure 5 provides for pivoting of the associated rails and stiles about an axis 46 which is perpendicular to the plane of the frame. In order to provide this function, the corner joint has two lapped portions 48, 50, one of which is provided with an aperture 52 and the other of which has a pin 54 with a slightly enlarged head which is a snap fit in the aperture 52 so that the enlarged head 56 holds the joint together, and so that the pin 54 can freely rotate in the aperture 52.In order to provide for connection of the joint to the rails and stiles, the portion 48 has a spigot 32 to fit into an end of a stile, and the portion 50 has a similar spigot 32 to fit into an end of tubular form of rail, each of the spigots having key-ways to fit co-operating splines in the rail and stile. The arrangement permits skewing of the frame in its own plane in order to take account of non-uniform expansion and contraction of the poster, and yet in combination with the spline and key-way arrangement described above resists twisting of the frame out of its own plane.

It will be appreciated that many other modifications and developments may be made to the frames described above. For example, referring to figure 2, rather than each corner joint 18 and its associated rail and stile being separately formed, these elements may be integral, so that in the case of the figure 1 arrangement the frame would be formed by two telescoping U-shaped sub-frames, and in the case of the figure 4 arrangement the frame would be formed from four L-shaped sub-frames. This would not, of course, provide the advantage of the arrangement shown in the drawings which permits the elements of the frame to be sold in a compact package with the rails and stiles packaged parallel to one another, for assembly by the end-user into the finished frame.

Claims (9)

1. A frame for an item of sheet material comprising: a set of frame members connected together to form the frame with an opposite pair of the members being movable towards and away from each other; means to attach an item of sheet material between said opposite pair of members so that the frame members frame the item; and means for resiliently biassing said opposite pair of members apart so as to tension the item; but not including a frame as disclosed in United Kingdom Patent Application No 8830430.8.

2. A frame for an item of sheet material, comprising: a set of frame members connected together to form the frame with an opposite pair of the members being movable towards and away from each other; means to attach an item of sheet material between said opposite pair of members so that the frame members frame the item; and means for resiliently biassing said opposite pair of members apart so as to tension the item; each connection of the members being such as to inhibit any substantial pivotal movement of the respective members relative to each other about axes lying in the plane of the frame.

3. A frame as claimed in claim 1 or 2, wherein at least one of the connections of the members includes means to permit pivoting of the respective members about an axis substantially perpendicular to the plane of the frame.

4. A frame as claimed in any preceding claim, wherein at least one of the connections of the members includes means to inhibit any substantial pivotal movement of the respective frame members.

5. A frame as claimed in claim 4, wherein the members have a degree of flexibility to permit skewing of the frame in its own plane.

6. A frame as claimed in any preceding claim, wherein the members extending between said opposite pair of members are each telescopic and spring-loaded in a direction to extend in length.

7. A frame as claimed in any preceding claim, wherein the attachment means to each of said opposite members comprises a pair of elements mounted adjacent opposite ends of each member and adapted to clamp the item of sheet material thereto, and means to bias the pair of elements away from each other to tension the item in the direction parallel to that member.

8. A frame as claimed in any of claims 1 to 6, wherein said opposite pair of frame members are each telescopic and spring-loaded to extend so as to tension the item of sheet material in a direction parallel to each of said opposite pair of frame members.

9. A frame for an item of sheet material, substantially as described with reference to the drawings.