GB2145462A - Securing layers of sheet material on studs and retaining collars therefor - Google Patents

Abstract

A method of securing flat objects such as carpeting and an underlayer in motor vehicles. A retaining collar (1) is mounted on a stud (13) by locking means (10) at the narrow end of a funnel- shaped conical body (2) of the collar, which has apertures (5) of which the edges provide abutments (17) for engagement by a tool to facilitate unscrewing of the collar from the stud. Individual collars (1) can be applied successively to a stud (13) to secure layers of material (14, 15, 16) independently, the collars stacking inside one another and the stud being of less height than the total thickness of the carpeting. The method enables the top layer of carpeting, when it has become dirty or worn, to be removed without disturbing or releasing any underlay. <IMAGE>

Description

SPECIFICATION Securing layers of sheet material on studs and retaining collars thereof This invention concerns securing layers of sheet material on studs and retaining collars therefor, and is more particularly concerned with retaining collars for securing layers of sheet material to a base support such as carpeting in motor vehicles, and the maner in which such collars can be used for this purpose.

A retaining collar is described in United States Patent Specification 3702024. The procedure there described is used for assembling a rigid plywood lining on a metallic inner wall of a cargo carrier, the plywood being drilled to provide a large hole within which, after placing the plywood in position on the wall, a smooth stud can be welded to the wall and the plywood panel thereafter secured by a retaining collar, or more particularly a spring retainer, pushed onto the stud. The spring retainer is said to be made of sheet metal and is generally conical in shape with a flange at the wide end and fingers to grip the stud at the narrow end and may be applied by a suitably shaped impact tool.Although it is said in the specification that the retainer can be removed by a similar tool, there is no clear description of how this can be achieved; in any event, the retainer would apparently be destroyed because it is said that a new one would be required to replace it.

A retaining collar also for use with a stud is described in German Gebrauchsmuster 8224277; this collar is detachable and suited for securing for instance carpeting and optionally an insulating mat to a base support such as a bonnet or a base plate of a motor vehicle.

The fastener of Gebrauchsmuster 8224277 is useful also in other applications in which flat objects have to be detachably attached to various kinds of supports.

Whereas the foregoing proposals are suitable for securing sheet materials, whether rigid or flexible, to a support, neither specification discloses a method which not only enables the material to be readily secured, but also enables a top sheet to be readily removed without disturbing others which may be underneath, a facility which may be especially desirable when the top sheet needs to be removed occasionally for cleaning or replacement and the flexibility or resilience of underplies makes it especially desirable that they remain permanently fastened.

It is accordingly an object of the present invention to provide an improved procedure and retaining collar therefore, with the aid of which several layers of flat flexible material can be separately secured to a stud on a support.

The foregoing object is achieved in accordance with the invention, which provides a method of securing a plurality of layers of sheet material comprising the steps of welding screw-threaded stud to a surface, applying one or more layers of sheet material to the surface with the stud accommodated in a hole in the material, pushing onto the stud, narrow end first, a retaining collar having a funnelshaped body with means at its narrow end for locking the collar on the study thread and with a retaining flange at its wide end which overlaps and thereby retains the layer of material, and applying at least one further layer of material and at least one further retaining collar, the body of which (or each of which) is largely accommodated in that of the preceding collar.

The invention also provides a retaining collar for securing a layer of sheet material in carrying out a method as set out in the last preceding paragraph comprising a funnelshaped body of circular cross section with locking means at its narrow end and a retaining flange at its wide end, characterised in that said locking means comprises resilient fingers enabling the collar to be pushed onto a screw thread and screwed off it, and the collar also comprises complimentary abutments accessible from inside its body and diametrically opposite one another for engagement by a suitable tool to facilitate unscrewing of the collar from the stud.

Preferably, a collar as referred to in the last preceding paragraph is moulded in one piece in a thermoplastic polymeric material, and may have apertures in the wall of the funnelshaped body, the edges of which provide the abutments to enable the collar to be unscrewed. The resilient fingers of locking means of such a collar may be disposed symmetrically about a central axis of the collar, and alternating with them around said axis may be guide ribs serving to centralise the collar on the stud when the fingers engage the stud thread.

Retaining collars in accordance with the invention allow several layers of flat flexible sheet material such as for instance carpeting, insulation panels or such like to be secured to a base support by means of weld studs. A specific advantage lies in that such layers are stackable individually. In practice, this means that when removing the layers lying at the top those lying below them remain firmly secured to the base support, so that not the whole lot of layers needs to be release, if for example the uppermost layer is to be removed for cleaning purposes or else is to replaced by a new one.

There now follows a description, to be read with reference to the accompanying drawings, of a retaining collar and a method of assembling layers of sheet material individually secured on a stud by a number of such collars, to illustrate the invention in its various aspects by way of example. This illustrative collar and the illustrative method in which it is used have been selected for description by way of example and not of limitation of the invention.

In the accompanying drawings; Figures la, ib and ic show a retaining collar according to the invention as viewed from the front, side (largely in section) and top respectively; and Figure 2 is a view in cross section of an assembly of layers of material each secured to the stud by a collar as shown in Fig. 1.

The illustrative collar 1 shown in Fig. 1 has a funnel-shaped body 2 with a conical wall 4.

While essentially funnel-shaped, the wall of the collar in accordance with the invention maybe of other than circular cross section, e.g. polygonal, though a polygonal collar would not usually be recommended where it is likely that a top one of a stack of collars is to be removed by unscrewing. The funnelshaped design of the body ensures that the collar can be arranged on a stud in a space saving manner, yet at the same time be positively retained, a number of such collars thereby being applied securely one on top of another in the form of a stack.

The collar 1 is provided with a facility 10 at the narrow end 11 of its body 1 for locking onto a stud. The locking facility 10 of the collar shown in Fig. 1 comprises fingers 7 (see Fig. 1 b) alternating with guide ribs 6, in a manner known in the prior art. It is the object of the locking facility 10 to form a detachable joint with the ridges of a stud. It is evident that the locking facility 10 can also be of any other suitable design as a function of the stud used for that purpose. Furthermore, it is also left to the discretion of one skilled in the art to arrange the locking facility 10 either inside the cone 2 as shown or to position it inside a separate cone which for example has been extended downwards.

At the wide end 3 of the cone 2 is provided a retaining flange 1 2. In the instance of the fastener having a conical body, this shoulder is in the form of a circular ring, sightly concave at its underside in radial section to make sure that the flange 1 2 bears down flatly around its periphery, so that a relatively high pressure can be exerted onto the object to be secured.

When using a collar with a conical body, or with a polygonal cross section, the retaining flange 1 2 may extend around its whole circumference or may be restricted to a few sections. There may well be applications in which it is not required to have an uninterrupted flange, but where it is sufficient or even desirable to have a flange for example only along the long sides of a pyramid of rectangular cross section.

The funnel-shaped wall 4 of a collar in accordance with the invention is mainly for the purpose of connecting the continuous flange to the locking facility. The wall need not be continuous. It may be interrupted by cut outs 5, so that the flange and locking facility are connected merely by an open frame work or cage. Both have a discontinuous flange and a discontinuous wall contribute to economy of material and consequential appreciable cost saving, especially in the mass production of collars for the car industry. In Fig. 2 are shown collars 1 stacked on top of one another, mounted on a threaded stud 1 3.

In carrying out the illustrative method, the collars secure independently an insulating mat 14, a cushioning layer 1 5 and carpeting 1 6 to a base support 17, for example a car body.

In such a case, it is plain that the collars introduced here can be used entirely as the situation demands; for example merely the insulating mat 14 may need to be secured and the other layers 15, 1 6 omitted.

It is also evident from Fig. 2 that there is theoretically no limit to the number of retaining collars which can be stacked one on top of another. If several layers are to be secured to one another, then the stud has to be correspondingly longer, but it is not intended that it should ever exceed the total thickness of the material disposed on the support.

In carrying out the illustrative method to form on assembly in accordance with the invention, as each layer of material 14, 1 5 and 1 6 is applied to the base support around the stud 13, a collar 1 is pushed down on the stud 1 3 to secure each layer independently.

The topmost collar can, however, be readily unscrewed by a suitable tool engaging abutments provided by the edges of the apertures 5 to release the uppermost layer 16 without disturbing the underplies 1 5 and 14.

Claims (9)

1. A method of securing a plurality of layers of sheet material on a surface comprising the steps of welding a screw-threaded stud (13) to said surface, applying one or more layers of sheet material (14, 15, 16) to the surface with the stud (13) accommodated in a hole in the material, pushing onto the stud (13), narrow end first, a retaining collar (1) having a funnel-shaped body (2) with means (10) at its narow end for locking the collar on the stud thread and with a retaining flange (12) at its wide end which overlaps and thereby retains the layer of material, and applying at least one further layer of material and at least one further retaining collar (1), the body (2) or which (or each of which) is largely accommodated in that of the preceding collar.

2. A retaining collar for securing a layer of sheet material on a stud in carrying out a method according to Claim 1 comprising a funnel-shaped body (2) of circular cross section with locking means (10) at its narrow end and a retaining flange (12) at its wide end, characterised in that said locking means comprises resilient fingers (7) enabling the collar (1) to be pushed onto a screw-thread and screwed off it, and the collar (1) also comprises complimentary abutments (17) accessible from inside its body and diametrically opposite one another for engagement by a suitable tool to facilitate unscrewing of the collar (1) from the stud (13).

3. A collar according to Claim 2 further characterised in that it is moulded in a thermoplastic polymeric material.

4. A collar according to Claim 3 further characterised in that said abutment (17) are provided by the edges of apertures (5) in the wall (4) of the funnel-shaped body (2).

5. A collar according to Claim 2 further characterised in that the resilient fingers (7) of said locking means (10) are disposed symmetrically about a central axis of the collar (1) and the collar also comprises guide ribs (6) alternating with said fingers around said axis, serving to centralise the collar (1) on a stud (13) when the fingers (7) engage the stud thread.

6. A method according to Claim 1 further characterised in that the retaining collars are ones according to any one of Claims 2, 3, 4 and 5.

7. A retaining collar substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

8. A method of securing a plurality of layers of sheet material to a support carried out substantially as herein before described with reference to Fig. 2 of the accompanying drawings.

9. A assembly comprising a plurality of layers of sheet material (14, 15, 16) secured to a threaded-weld stud (13) by a method according to Claim 1.