GB2121864A

GB2121864A - Hose clamps

Info

Publication number: GB2121864A
Application number: GB08217682A
Authority: GB
Inventors: Clinton G Smith
Original assignee: Smith W H & Sons
Current assignee: Smith W H & Sons
Priority date: 1982-06-18
Filing date: 1982-06-18
Publication date: 1984-01-04

Abstract

The clamp comprises a moulded plastics member 10 and an internally threaded fastener 11. The member 10 comprises a flexible substantially inelastic strap 12, an externally screw- threaded portion 13 and a body 14, and is moulded in one piece from a plastics material, having a high tensile strength. In use, the portion 13 is inserted into a passageway through the body 14 and the fastener 11 is screwed onto portion 13. <IMAGE>

Description

SPECIFICATION Improvements relating to fastening devices for hoses This invention concerns improvements in or relating to fastener devices for hoses and like elongate member.

For fastening a hose to a cylindrical body, it is known to use metal fastener devices which are often referred to as "clips", for example "Jubiliee" (R.T.M.) clips, of the kind comprising a metal strap having one end portion secured to a worm assembly and having the other end portion shaped to provide a rack to engage the worm, so that the worm can be rotated to draw the other end portion through the worm, whereby to constrict the strap around the hose and thereby clamp the hose around the cylindrical body. Such fastener devices have many other uses, e.g. to clamp hose connectors to taps, and may be used as bundling ties to fasten together, in a bundle, several elongate members such as cables, rods, tubes and the like, and have the advantage that they can exert high clamping pressures.However such fastener devices have several disadvantages in that they are expensive to manufacture, they corrode or have to be made, at even greater expense, from corrosion resistant materials, the rack is exposed to and traps debris which can cause damage and prevent the clip being released, are subject to rapid rack wear when released and tightened repeatedly and can cut into the hose.

What is needed is a fastener device which can be used repeatedly without being subject to rapid wear and which can be constructed so as to obviate or reduce the other aforementioned disadvantages, whilst retaining the ability to exert a high clamping pressure.

According to the present invention there is provided a fastener device comprising a moulded plastics member, wherein said member comprises a flexible elongate strap, an externally threaded screw portion at one end of the strap and a hollow body at the other end of the strap, wherein said body has a mouth at one end through which the screw portion may be inserted into the body and an abutment at the other end beyond which the screw portion projects in use to receive an internally threaded fastener so that the fastener abuts the abutment.

The body and screw portion are preferably mutually shaped to interengage so as to permit longitudinal movement of the screw portion whilst restricting rotational movement of the screw portion relative to the body. For example, a tongue may be provided in the body to engage in a groove in the screw portion, or the screw portion and body interior may have non-circular crosssections. Also, a part or parts of the strap portion may engage in the body to resist rotation.

The ends of the strap are preferably thickened and shaped to merge smoothly with the body and screw portion whereby to avoid abrupt changes in cross section at the ends of the strap.

The invention will be described further, by way of example with reference to the accompanying drawings, wherein:~ Figure 1 shows a fastener device of the invention in side elevation; Figure 2 shows, in part sectional side elevation, a moulded plastics member of the fastener device, in an as-moulded condition; Figure 3 shows a section on the line lil~lil in Figure 1; Figures 4 and 5 are enlarged longitudinal sectional and transverse cross-sectional views of a body and screw portions of the moulded plastics member; and Figures 6 and 7 are views similar to Figures 4 and 5 showing a modified form of the plastics member.

The fastener device comprises the moulded plastics member 10 and an internally threaded fastener 11. The member 10 comprises a flexible substantially inelastic strap 12, a screw portion 13 and a body 14, and is moulded in one piece from a plastics material, such as Nylon, having a high tensile strength.

The strap 12 may be of rectangular, substantially rectangular or oval transverse crosssection, but is preferably of a cross-section which is ridged or convex to provide a longitudinal protuberance 20 on one side of the strap; and the ends 21 and 22 of the strap preferably taper in thickness to merge smoothly with the body 14 and screw portion 13 to avoid abrupt major changes in the cross-section of the strap at its junctions with the body 14 and portion 13.

The screw portion 13 has an external thread 30 and has a circular or substantially circular transverse cross-section. In the form shown in Figures 4 and 5, the screw portion 13 is provided with a longitudinal groove 31. In all forms, the portion 13 is thicker than the strap 12, and is therefore considerably stiffer than the strap and relatively inflexible.

The width of the strap may be the same or less than the overall diameter of the screw portion, or as shown in Figures 6 and 7, said width may be greater than said diameter.

The body 14 is hollow and has an interior 40 which extends from a mouth 41 at one end of the body to an abutment 42 at the other end of the body. The interior 40 may be of cylindrical shape, but in the form shown in Figures 4 and 5 a longitudinal tongue 43 projects into the interior to engage in the groove 31, whereas in the form shown in Figures 6 and 7 the interior includes two diametrically opposed grooves 44 to receive margins 23 of the strap.

The end 21 of the strap 12 merges with the periphery of the body adjacent the mouth 41.

In use, the strap is bent around a hose or other member or members and the free end 32 of the screw portion 13 is inserted into the body 14 via the mouth, and is pushed through the interior until the free end 32 projects beyond the abutment 42 to receive the fastener 11, as shown in Figure 1.

When the fastener 11 is rotated to draw the screw portion further through the body, the loop formed by the strap is reduced and tightens around the hose. If the material of the hose is soft or resilient the protuberance 20 becomes embedded in the hose to a depth which is restricted by the flanking surfaces 24.

It will be readily appreciated that the tongue and groove in the form shown in Figures 4 and 5, and the grooves and margins in the form shown in Figures 6 and 7 interengage to serve as means to prevent rotation of the screw portion relative to the body. Alternatively one or more interengagiing flats or other surfaces may be provided on the screw portion and in the interior of the body to serve as said means.

The fastener device may be used repeatedly and in use the screw portion is substantially protected and provides a greatly increased working length of thread in engagement with the fastener when compared with a known clip of equivalent strap width. The fastener device is inexpensive to manufacture and may be used with any suitable internally threaded fastener.

Claims

1. A fastener device comprising a moulded plastics mamber, wherein said member comprises a flexible elongate strap, an externally threaded screw portion at one end of the strap and a hollow body at the other end of the strap, wherein said body has a mouth at one end through which the screw portion may be inserted into the body and an abutment at the other end beyond which the screw portion projects in use to receive an internally threaded fastener so that the fastener abuts the abutment.

2. A fastener device as claimed in Claim 1 wherein the body and screw portion are mutually shaped to interengage so as to permit longitudinal movement of the screw portion whilst restricting rotational movement of the screw portion relative to the body.

3. A fastener device as claimed in Claim 2 wherein the width of the strap is greater than the overall diameter of the screw portion, and wherein two diametrically opposed grooves extend longitudinally of the interior of the hollow body to receive margins of the strap.

4. A fastener device as claimed in Claim 1 , 2 or 3 wherein the ends of the strap are thickened and shaped to merge smoothly with the body and screw portion.

5. A fastener device as claimed in Claim 1,2,3 or 4 wherein a protuberance extends longitudinally along one side of the strap.

6. A fastener device substantially as hereinbefore described with reference to Figures 1 and 2, or Figures 1 and 2 as modified by Figures 4 and 5 or Figures 6 and 7 of the accompanying drawings.