Tensioning sheet material

Description

TECHNICAL FIELD OF THE INVENTION

This invention relates to the tensioning of sheet material such as PVC, canvas and other textiles for forming banners, signage, vehicle graphics and the like.

BACKGROUND ART

Many methods of tensioning sheet material have been proposed, some of which have employed rivets for attachment to a frame, while another has utilised rods in a peripheral hem of the sheet material for insertion into a complemental channel in the frame.

It is an object of the present invention to provide a very simple arrangement which is easy to use and which results in a firm anchor as well as an excellent aesthetic appearance.

DISCLOSURE OF THE INVENTION

According to the invention an assembly for the tensioning of sheet material in a frame includes a channel in the frame adapted to receive the sheet material and a flexible strip having formations which are a force-fit into the channel to hold the sheet material therein and which, on release expand against the sheet material for a positive anchorage.

In a preferred form of the invention the channel has an opening which is narrower than the channel and the strip has feet which engage under the opening when released from the step of force-fitting into the channel.

The strip may be made from a suitable polymeric material and which includes a portion insertable into the channel of the frame and a top portion which has a surface which is aesthetically chosen for the particular article involved.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is described below with reference to the accompanying drawings, in which:

FIG. 1 is an isometric view of a strip for use in the invention;

FIG. 2 is a cross sectional view thereof;

FIG. 3 is an isometric view of a portion of a channel for a frame;

FIG. 4 is a sectional view thereof;

FIG. 5 is an isometric view of an alternative shape of frame;

FIG. 6 is a sectional view thereof;

FIG. 7 is an isometric view of a further alternative shape of frame;

FIG. 8 is a sectional view thereof;

and

FIG. 9 is an isometric view of a corner of a frame in assembled state.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 3 illustrates a simple form of frame 10 which comprises a channel with overhang 12 thereby constituting a narrow opening 14. FIGS. 5 and 7 are alternative shapes, each having an extension such as the arm 16 of FIG. 5 or the box section 18 of FIG. 7.

The strip 20—see FIGS. 1 and 2 is an extrusion of polymeric material which has a resilient zone 22 with feet 24. The width of the feet exceeds the width of the opening of the channel.

The sheet material is located over the frame and the strip is force-fitted into the channel to capture the sheet material 21 between the zone 22 and the channel. It may be necessary to use a mallet to effect the force-fit of the zone 22 into the channel. Once into the channel the zone 22 relaxes and engages the sheet material in the channel below the edges of the narrow opening thereof—see FIG. 9.

The top surface 30 of the strip may be plain or patterned to suit the requirements. In FIG. 9 it is slightly curved in cross-section and hides the channel from view.