GB2193550A - Fixing device - Google Patents

Abstract

A fixing device for retention in a hole (11) in material comprises a metal sleeve including a hollow cylindrical or tapered shank which may be slotted longitudinally, a head (4) at one end of the shank and a tapered portion at its other end, and an expander pin (5) retained between a pair of internal protrusions (6, 7). There is a further internal protrusion (8) towards the narrow end of the shank. In use, the shank is driven into the hole (11) which hole has a slightly smaller internal diameter than the external shank diameter. Matting, for example, is retained between the material and the head (4). The pin (5) is then driven along the shank into the part thereof in the masonry to maintain the interference fit of the sleeve in the hole. When the pin engages the protrusion (8) it can splay the shank and so that it bites into the material if it is relatively soft. <IMAGE>

Description

SPECIFICATION Fixing device This invention relates to a fixing device for use in providing a fixing into a hole formed in material, for example concrete or masonry.

A fixing device has been proposed having a hollow split sleeve which is passed into a hole formed in a hard material, and a pin of slightly larger diameter than the normal internal diameter of the sleeve is driven into the sleeve within the hole in order to expand the sleeve against the internal wall of the hole to lock it firmly in position. Whilst this arrangement is generally satisfactory for many applications, it has been found that in particularly hard materials and/or when the dimensional tolerance between the sleeve and hole wall is close, it is possible for the pin to jam in the sleeve before being driven fully home and it is then necessary to trim off the protruding part of the pin, giving rise to some inconvenience. It is, moreover, possible for the pins or sleeves to become separated on site prior to use, and retrieval of the missing parts can lead to inconvenient delay.

An object of the present invention is to provide an improved fixing device which alleviates or eliminates the aforesaid problems. The invention also provides a method of making the improved fixing device and a method of using the device to provide a fixing in hard material, such as masonry or concrete.

According to the present invention, a fixing device comprises a hollow longitudinally split sleeve for insertion into a smaller hole formed in material, and a pin which is shorter than or equal in length to the sleeve, the internal sleeve aperture and pin being shaped and/or dimensioned so that, in use, a part of the sleeve is received in the hole in the material, said part being received as an interference fit, the pin being movable along the sleeve tightly to retain said part of the sleeve in the hole.

In one convenient arrangement with soft material, the sleeve is provided with an internal protrusion towards a forward end thereof for engagement by the pin to splay out the end portion to bite into the material containing the hole.

Preferably, the pin is retained within the sleeve, prior to use of the device, to form, with the sleeve, a self-contained assembly from which the pin will not ordinarily become detached. This is of considerable general advantage on a building site in which separate components are readily misplaced and lost and it can be additionally advantageous when the device is being used in an overhead location, as in providing a fixing for an overhead floor or ceiling for example, from which items may be readily dropped.

In a typical practical arrangement, the pin is retained axially between a pair of internal protrusions towards the rearward end of the sleeve.

According to a further aspect of the invention, a method of forming a fixing to material comprises providing a fixing device which comprises a hollow longitudinally split sleeve and a pin which is shorter than or equal in length to the sleeve, providing an undersized aperture in said material, forcing part of the sleeve into said aperture, said part being an interference fit therein, and moving the pin along the sleeve tightly to retain said part of the sleeve in the aperture.

According to another aspect of the invention, a method of making a fixing device comprises providing a flat plate and forming a pair of protrusions towards one end thereof, rolling the plate into the form of a hollow tubular sleeve with the protrusions on its internal surface, and inserting into the sleeve a pin which is retained between said pair of protrusions.

Preferably, the sleeve may be formed with a taper narrowing away from its said one end, and may be formed also with an outwardly turned flange at its said one end to serve as a head. Additionally a further protrusion may be formed towards the other end of the plate, the further protrusion being on the internal surface of the sleeve.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a side elevation of one form of the fixing device of the invention; Figure 2 is a longitudinal cross-section of the device shown in Figure 1, and Figure 3A to 3D illustrate various stages involved in carrying out the method of the invention to effect a fixing operation.

The fixing device illustrated in Figures 1 and 2 includes a metal sleeve, indicated generally by the reference numeral 1, having a hollow, cylindrical shank 2 along which is formed a longitudinal slot 3.

Alternatively the shank could be slightly tapered. The larger end of the shank 2 has a peripheral radial flange 4 which acts as a head. The narrower end of the shank is tapered so as substantially to close the slot and form a lead-in 2a for the forward end of the shank.

Within the sleeve is housed a cylindrical, metal expander pin 5 which is retained in position near the larger end of the sleeve, prior to the device being used, by a pair inwardly directed protrusions 6, 7 which may conveniently be formed by pressing or rolling for example. Such retention of the expander pin is advantageous in that it not only prevents the sleeve and pin from becoming separated when lying around on site, but also enables the device to be used readily in a generally vertical position without the pin falling out. In this example, a further protrusion 8 is formed, again conveniently by pressing or rolling, to wards the narrow end of the tube for the purpose to be described. However the protrusion 8 can be omitted.

One typical use of the fixing device of the invention is to secure a layer of insulating matting 9 to the surface of a masonry or concrete wall 10, and the first step in the fixing method is to drill a hole 11 through the matting and into the wall, ensuring that the depth of the hole is slightly longer than the length of the sleeve 1 to be received within it. The hole should also have a diameter slightly smaller than the maximum external diameter of the shank of the sleeve. The forward end of the shank of the fixing device is then inserted into the hole 11 and the insertion of the shank 2 completed by driving it home until the flange 4 of the sleeve 1 comes into engagement with the outer face of the matting 9. The full diameter portion of the shank received in the hole 11 is received as a firm interference fit.

Accordingly during insertion the opposite edges of the slot in said full diameter portion are forced towards each other, and an outwardly projecting peripheral shoulder 12 is thus formed in the region of the interface between the wall and the matting. The shoulder 12 thus effectively abuts against the wall 10 and once the shank flange 4 engages the matting as shown in Figure 36, the shoulder acts to assist the head 4 in resisting further movement of the sleeve into the hole.

The next step is to insert a drift member 13 into the anchored sleeve and, by hammering this, to dislodge the pin 5 from its retention by the projections 6 and 7, enabling the pin to be pushed along the sleeve into a forward end portion thereof within the masonry where it ideally assumes a tight fit to retain the shank tightly against the wall of the hole. If the pin is finally driven to the end of the shank, it will come into engagement with the forward projection 8 and act in conjunction with this to splay out the extreme forward end portion of the sleeve, whilst still retaining the part of the shank behind the protrusion tightly against the wall of the hole. If the masonry is relatively soft, the splayed out end portion of the sleeve may bite into the masonry at regions 8A, as illustrated, although this would not happen to any great extent for example in very hard concrete.The drift 13 may then be withdrawn, leaving the fixing device securely in position in the masonry and retaining the matting 9 in its desired position.

The provision of the lead-in portion 2a reduces any tendency for the forward end of the shank to dig its own larger hole in the material 10 and push material in front of it when the shank is driven in, which would result in reduced pull-out resistance. It also provides easier location into the hole drilled through the matting.

It will be seen that, because the pin 5 is relatively short as compared with the sleeve, this will remain entirely hidden within the sleeve in its fixing position and obviate any necessity for trimming off projecting end portions of the pin, as is necessary with some conventional devices. Moreover, the facility for retaining the pin 5 within the sleeve prior to the latter being used in a fixing operation means that, as previously mentioned, the in convenience of pins and sleeves being separated and lost on site is eliminated, and that the use of the fixing device in overhead locations, such as for ceiling fixing, is facilitated because the pin cannot readily fall out of the sleeve.

If a hollow, longitudinally split sleeve alone were to be driven into an undersized diameter hole, the sleeve would initially be a tight fit therein. However, in time, this grip provided by the sleeve trying to recover its undeformed shape would weaken due to metal fatigue, to permit easy pull-out of the sleeve. The fixing device of the invention overcomes this by the pin substantially permanently retaining the tight engagement of the part of the sleeve against the hole surface. With soft material there is the assistance of splaying of the forward sleeve end if the protrusion 8 is provided. The pin could be driven in from wholly outside of the sleeve.

The device may very conveniently be made by commencing with a flat metal sheet, as of stainless steel for example, and using a pressing or rolling operation to form the protrusions 6 and 7, and protrusion 8 if required, rolling the plate into its tubular form with the protrusions on its internal surface, and inserting the pin as a 'snap-fit' into the sleeve to be retained between the protrusions 6 and 7. The flange 4 and end 2a are preferably formed during said rolling operation.

Instead of matting, the fixing device is also effective in securing timber to material 10 such as masonry, since there can be an additional interference fit of the sleeve in an undersized hole in the timber as well as the masonry, if the timber is relatively thick.

Another application is to secure a metallic bracket to the masonry or concrete 11.

Claims (22)

1. A fixing device comprising a hollow longitudinally split sleeve for insertion into a smaller hole formed in material, and a pin which is shorter than or equal in length to the sleeve, the internal sleeve aperture and pin being shaped and/or dimensioned so that, in use, a part of the sleeve is received in the hole in the material, said part being received as an interference fit, the pin being movable along the sleeve tightly to retain said part of the sleeve in the hole.

2. A fixing device as claimed in claim 1, wherein the sleeve is provided with an internal protrusion towards its forward end, for engagement by the pin to splay said end of the sleeve.

3. A fixing device as claimed in claim 1 or claim 2, wherein a forward end part of the sleeve is inwardly tapered.

4. A fixing device as claimed in any one of the preceding claims, wherein at its rearward end, the sleeve has a head.

5. A fixing device as claimed in any one of the preceding claims, wherein said sleeve has a shank which is tapered along its length, the shank narrowing in a direction towards its forward end.

6. A fixing device as claimed in any one of the preceding claims, wherein said sleeve has a shank which is cylindrical along its whole length or substantially its whole length.

7. A fixing device as claimed in any one of the preceding claims, wherein, prior to the use of the device, the pin is retained within the sleeve, to form, with the sleeve, a self-contained assembly from which the pin will not ordinarily become detached.

8. A fixing device as claimed in claim 7, wherein the pin is retained axially in the sleeve between a pair of internal protrusions towards a rearward end of the sleeve.

9. A fixing device as claimed in any one of the preceding claims, wherein said pin is cylindrical.

10. A method of forming a fixing to material comprises providing a fixing device which comprises a hollow longitudinally split sleeve and a pin which is shorter than or equal in length to the sleeve, providing an undersized aperture in said material, forcing part of the sleeve into said aperture, said part being an interference fit therein, and moving the pin along the sleeve tightly to retain said part of the sleeve in the aperture.

11. A method as claimed in claim 10, wherein the pin is driven to a position where it engages an internal protrusion adjacent a forward end of the sleeve, such engagement causing the extreme forward end portion of the sleeve to splay out.

12. A method as claimed in either of claims 10 and 11, wherein the pin is driven along the sleeve from a position where it is held axially in the sleeve between a pair of internal protrusions towards a rearward end of the sleeve.

13. A method as claimed in any one of claims 10 to 12, wherein the pin is driven to a position where it is contained wholly within the sleeve.

14. A method of making a fixing device comprises providing a flat plate and forming a pair of protrusions towards one end thereof, rolling the plate into the form of a hollow tubular sleeve with the protrusions on its internal surface, and inserting into the sleeve a pin which is retained between said pair of protrusions.

15. A method as claimed in claim 14, wherein the sleeve is formed with an outwardly turned flange at its said other end to serve as a head.

16. A method as claimed in either of claims 14 and 15, wherein an end part of the sleeve adjacent said first protrusion is tapered to narrow towards said one end.

17. A method as claimed in any one of claims 14 to 16, wherein the sleeve is formed with a shank having a taper along its length, the shank narrowing in a direction towards its said one end.

18. A method as claimed in any one of claims 14 to 17, wherein said sleeve is formed with a shank which is cylindrical along its whole length or substantially its whole length.

19. A method as claimed in any one of the preceding claims, wherein said plate is of metal and said protrusions are formed by a pressing or rolling operation.

20. A fixing device substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

21. A method of forming a fixing substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

22. A method of making a fixing device substantially as hereinbefore described with reference to the accompanying drawings.