GB2102905A

GB2102905A - Improvements in captive nuts

Info

Publication number: GB2102905A
Application number: GB08220876A
Authority: GB
Inventors: Alan Williams
Original assignee: CANNING BRETT Ltd
Current assignee: CANNING BRETT Ltd
Priority date: 1981-07-27
Filing date: 1982-07-19
Publication date: 1983-02-09
Also published as: GB2102905B

Abstract

A U-shaped captive nut made of sheet metal has two tangs 16, 17 pressed out of the plane of one of the arms, the edges 18, 19 of which are substantially straight and parallel so that a screw will engage between the tangs at only one point along each edge, whereby screws passing through the nut at various angles and at various lateral positions may engage with the tangs. <IMAGE>

Description

SPECIFICATION Improvements in captive nuts The invention relates to captive nuts of the type in which the nut clips onto the peripheral edge of panel of sheel material, in register with a slot or aperture in the panel, so as to receive a screw passing through the aperture or slot.

Such a captive nut normally comprises a strip of metal bent into a U-shape, the two arms of the U being urged together, by virtue of their resilience, to embrace the edge of a panel over which the nut is applied, one arm of the U being formed with a slot or aperture through which a screw may freely pass, and the other arm of the U having two tangs pressed out of the plane thereof, the free opposing edge of the tangs being so shaped and disposed as to engage the threaded portion of a screw passed between them.

Hitherto, it has been the practice for the opposed edges of the tangs to be concavely curved so that each tang partly embraces the screw as it passes through the nut, thus locating the screw transversely of its length. Also, the edges of the tangs are normally tilted in opposite directions relatively to the surface of the nut, so that each is inclined at substantially the same angle as the adjacent thread on the screw.

It has been found that conventional captive nuts, due to the shaping of the tangs, may not engage correctly with screws which do not extend substantially normally to the plane of the panel, and hence to the plane of the nut. In some applications, however, screws may frequently be disposed at anything up to 80 from the normal, and there is therefore a requirement for a captive nut which can accommodate such variations in the angle of the screw. Similarly, conventional captive nuts are not able to accommodate misalignment of the screw in a transverse direction even though the screw is presented in the correct angular alignment.

According to the invention there is provided a captive nut of the kind first referred to wherein the free opposing edges of said tangs are substantially straight and parallel as viewed in a direction at right angles to the surface of the nut.

Since the edges of the tangs are straight and parallel instead of being concavely curved, the screw may engage between the tangs at any point along the straight edges thereof and thus screws passing through the nut at various angles and at various positions will still engage with the tangs.

Preferably each of the opposing edges of the tangs is also parallel to the surface of the nut. The edge on one tang may be spaced further from the surface of the nut than the edge on the other tang so that each tang can engage between convolutions of the screw thread on the side of the screw adjacent thereto.

The aforesaid slot or aperture in the first said arm of the U-shaped strip is preferably elongate in the direction of said parallel edges of the tangs.

For example, the aperture may comprise a generally oval aperture having rounded ends.

Preferably the length of the slot or aperture is greater than the length of said edges of the tangs, and the width of the aperture is greater than the distance apart of said edges.

The following is a detailed description of an embodiment of the invention reference being made to the accompanying drawings in which: Figure 1 is a side elevation of a captive nut, Figure 2 is an elevation of the captive nut in position on the edge of a panel of sheet material, Figure 3 is a side view of the captive nut when in use to secure together two panels of sheet material, Figure 4 is a view in the direction of arrow "A" in Figure 3, Figure 5 is a similar view to Figure 3 showing the nut in use with an angularly misaligned screw, and Figures 6a and 6b show alternative forms of apertures in panels with which the nut is to be used.

Referring to Figure 1, the nut comprises a generally U-shaped strip 10 of hardened and tempered spring steel, the two arms of the U being indicated at 11 and 12. An elongate slot 13 is formed in the strip 10 between the two arms thereof to facilitate bending of the strip into the U-shape. The free ends of the two arms 11 and 12 are urged together by virtue of the resilience of the steel from which the nut is made.

The arm 11 of the nut is formed with an oval aperture 14 having bent-up lugs 1 5 at each side thereof. The arm 1 2 of the nut has two tangs 1 6 and 1 7 bent out of the surface thereof, the tangs having spaced opposed edges 18, 19 which are parallel to one another as viewed in a direction at right angles to the surface of the arm 12.

As will be seen from Figures 1 and 3, the edges 18, 19 are parallel to the surface of the arm 12, but the edge 1 9 is spaced further from the surface than the edge 1 8. This staggered arrangement ensures that the edges engage between the convolutions of the screw thread at opposite sides of a screw 27 passing between them, as best seen in Figure 3.

In use, the nut is applied over the peripheral edge of a sheet metal panel 20 which may be formed adjacent the edge with an open-mouthed slot 21 (see Figure 6a) which registers with the aperture 1 4 in the nut and with the space between the tangs 16 and 17. The free end of the arm 12 of the nut is formed with an upturned portion 22 to facilitate application of the nut onto the edge of the panel 20. The bent up lugs 1 5 serve to guide the nut into engagement with the slot 21.

Alternatively, as shown in Figure 6b, the panel 20 may be formed with an elongate hole 22 into which the lugs 1 5 snap as the nut is applied to the edge of the panel. The upper edges of the lugs 15 are inclined as they extend away from the open side of the U-shaped strip, so as to facilitate the application of the nut to the edge of the panel 20.

When the nut is in position on the panel 20, the screw 27 is passed through an elongate aperture 23 in the item 24 which is secured to the panel 20, for example a trim strip on a motor vehicle, and is then passed through the aperture 14 and slot 21 and into the space between the edges 1 8 and 19 of the tangs 16 and 17. The screw is then screwed into engagement with those edges and since the edges are parallel any portion of the edges may be engaged by the threads of the screw. Consequently, the nut will accommodate screws passing at various positions through the panels 20 and 24, as indicated by the arrows 25 in Figure 3, or passing at various angles through the panels, as indicated by the arrows 26 in Figures 4 and 5.

The aperture 14 in the arm 11 of the nut is elongate so as also to accommodate various angles and positions of the screw, but it will be appreciated that the aperture may be of any other desired configuration and might, for example, also be circular. It might also be in the form of an openended slot.

Claims

1. A captive nut comprising a strip of metal bent into a U-shape, the two arms of the U being urged together, by virtue of their resilience, to embrace the edge of a panel over which, in use, the nut is applied, one arm of the U being formed with a slot or aperture through which the screw may freely pass, and the other arm of the U having two tangs pressed out of the plane thereof, the free opposing edges of the tangs being so shaped and disposed as to engage the threaded portion of a screw passed between them, the free opposing edges of said tangs being substantially straight and parallel as viewed in a direction at right angles to the surface of the nut.

2. A captive nut according to claim 1, wherein each of the opposing edges of the tangs is parallel to the surface of the nut.

3. A captive nut according to claim 1 or claim 2, wherein the edge on one tang is spaced further from the surface of the nut than the edge on the other tang.

4. A captive nut according to any of claims 1 to 3, wherein the slot or aperture in the first said arm of the U-shaped strip is elongate in the direction of said parallel edges of the tangs.

5. A captive nut according to claim 4, wherein the aperture comprises a generally oval aperture having rounded ends.

6. A captive nut according to any of claims 1 to 5, wherein the length of the slot or aperture in the first said arm of the U-shaped strip is greater than the length of said edges of the tangs, and the width of the aperture is greater than the distance apart of said edges.

7. A captive nut according to any of claims 1 to 6, wherein the first arm of the U-shaped strip is formed with projecting lugs at opposite sides of the slot or aperture therein, said lugs projecting towards the other arm of the U-shaped strip.

8. A captive nut according to claim 7, wherein the edges of said lugs are inclined away from the first arm of the U-shaped strip as they extend away from the open side of the strip.

9. A captive nut substantially as hereinbefore described with reference to the accompanying drawings.