GB2181468A - Locking device for an elongate element. eg, a wall tie - Google Patents

Abstract

A locking device for securing an elongate element 21 in an opening, such as one end of a wall tie 15, comprises an abutment 25, a locking part 26, and at least one locking ring 31, the locking ring 31 being positioned between the locking part 26 and the abutment 25, the locking ring 31 being expandable into engagement with the inside surface of the opening 15 upon relative rotation between the locking part 26 and the elongate element 21 which reduces the separation between the locking part 26 and the abutment 25, an expandable locking member 60 being provided to lock the locking part 26 against rotation in the opening 15, at least the outermost end of the locking part 26 being received in the locking member 60 and the locking part having an outer cam surface (51 Fig. 3) which upon the locking part 26 being urged further inwardly of the locking member 60, causes the locking member 60 to expand outwardly to engage the inside surface of the opening. <IMAGE>

Description

SPECIFICATION Locking device for an elongate element This invention relates to a locking device for securing an elongate element within an opening in a structure and more particularly, but not exclusively, to a locking device for securing an elongate element comprising a wall tie, in an opening. However, the invention may be used to secure other elongate elements such as screws or bolts which are used to attach articles such as brackets to a structure, which brackets may be used to support shelves or the like. Alternatively, such elongate elements comprise studding to which articles are attached, spaced from the surface of the structure, which studs or other elongate elements may be used to rest articles such as shelves thereon directly.

Original wall ties, i.e. those which are secured in position by the bricklayer during the original construction of a cavity wall structure, tend in time to rust through due to the presence of moisture in the cavity, and the inner and outer walls thus become relatively movable. To prevent the building collapsing, it is necessary to secure new wall ties in position.

In the past, because access cannot be gained to the cavity, it has been necessary to dismantle the inner, or more usually outer, wall, secure new ties in position and reconstruct the inner or outer wall. This is obviously costly, time consuming and very inconvenient.

More recently, remedial wall ties have been developed which can be located in position without the need to dismantle either the inner or the outer wall. An opening is bored through, usually the outer wall for each tie, into the inner wall but usually not extending through the inner wall. The tie is then passed through the bore in the outer wall, an inner end of the tie extending into a blind opening in the inner wall and being provided with a device to lock the inner end of the wall tie in the blind opening in the inner wall. The outer end of the wall tie is then secured relative to the outer wall.

In other applications, such as securing an elongate element, such as a screw within an opening in a structure such as, for example, a masonry wall, the usual method of securing the screw is to plug the opening with an insert and insert a screw threaded end of the screw by rotation, into the insert. The insert expands and hence frictionally grips the inside surface of the opening and prevents withdrawal of the elongate element.

Where studding is concerned, it is at present necessary to fix the studding in position, with for example cement, the cement trapping an abutment such as a hook, to prevent withdrawal.

It is an object of the present invention to provide a new or improved locking device for securing an elongate element within an opening in a structure.

According to one aspect of the invention, we provide a locking device for securing an elongate element in an opening, the device comprising an abutment, a locking part, and at least one locking ring, the locking ring being positioned inwardly of the end of the element between the locking part, and the abutment, the locking ring being expandable into engagement with the inside surface of the opening upon relative rotation between the locking part and the elongate element, which reduces the separation between the locking part and the abutment, an expandable locking member being provided to lock the locking part against rotation in the opening, at least the outermost end of the locking part being received in the locking member, and the locking part having an outer cam surface which upon the locking part being urged further inwardly of the locking member, causes the locking member to expand outwardly to engage the inside surface of the opening.

It has been faund that such a locking means provides an efficient means of restraining the locking part against rotation in the opening.

Thus upon the elongate element being rotated, relative rotation can occur between the locking part and the elongate element to reduce the separation between the locking part and the abutment, to cause the locking ring (or rings) to expand outwardly.

The locking part may be urged further inwardly of the locking member upon an axial movement of the elongate element, inwardly of the opening. For example, the opposite end of the elongate element may be struck with a hammer.

In order to resist axial movement of the locking part away from the abutment and to cause the separation between the locking part and the abutment to decrease upon relative rotation between the locking part and the abutment, the end of the elongate element on which the locking part is received, and the locking part may have corresponding screw threads.

It will be appreciated that a significant frictional force will be developed between the locking member and the locking part as the locking part is urged further inwardly of the locking member. This in itself may be sufficient to resist relative rotation occurring between the locking member and locking part.

Preferably however, the locking part and locking member each have co-operating formations which abut and prevent relative rotation occurring.

For example, the locking part may have an axially extending groove in its outer surface, and the locking member may have an inwardly extending tongue which is received in the groove and rides along the groove as the locking part is urged further inwardly of the locking member.

The cam outer surface of the locking part is preferably conical. The locking part may have at its outer end a region of constant smaller diameter which extends along the locking part from the end to the smallest diameter end of the conical surface, and at its other end, the locking part may have a region of constant but greater diameter which extends from the innerrnost end to the larger diameter end of the conical surface.

Thus the smaller diameter end can be easily received within the locking member without any, or with minimal expansion of the locking member occurring, but when the locking part is urged further inwardly of the locking member so that the conical surface engages the locking member, the locking member is caused to expand.

The locking part preferably comprises a sleeve having a slit which extends along its entire length, to enable the sleeve to expand.

The inwardly extending tongue, where provided, may comprise a deformed part of the periphery of the or another slit.

Alternatively, or in addition, a slit may be provided which extends along part way along the length of the sleeve to facilitate sleeve expansion, preferably from the end of the sleeve in which the locking part is received.

Preferably the locking member has at least one outwardly extending projection which is forced outwardly into engagement with the inside surface of the opening, when the locking member is expanded.

A plurality of such outwardly extending projections are preferably provided. For example, a plurality of cuts may be provided in the sleeve, the periphery of the cuts being deformed outwardly to provide a pair of ears for each cut.

For example, the cuts may comprise axially extending cuts from the end of the locking member in which the locking part is received.

The ears preferably are sharp to facilitate their engagement and/or digging in to the inside surface of the opening.

The locking member may be made of spring steel or any other suitable material. Preferably the locking ring of the device has a plurality of fingers extending radially outwardly, means being provided to cause the fingers to move outwardly into engagement with the inside surface of the opening as the locking ring is expanded.

Such an arrangement enables the locking device to be used to secure the elongate element in a wide variety of structures. In soft materials, the fingers of the locking ring can thus dig into the surface of the opening, whereas in harder materials, the fingers can dig in and/or deform to provide adequate friction, to resist high withdrawal forces.

The fingers of the locking ring may be made of a material such as plastic or soft metal which is malleable so that as the fingers are urged outwardly they become deformed making withdrawal of the element from the opening increasingly difficult.

The fingers may comprise a splayed end of the locking ring separated by slits cut axially of the ring, the outermost edges of the fingers providing abutment portions which engage i.e. frictionally engage and/or dig into the inside surface of the opening.

The locking ring may have fingers at each end, the fingers at each end being, in use, urged outwardly as the separation between the abutment and the locking part is reduced.

An element may be provided intermediate the locking part and the ring to engage one end of the locking ring and an element of the abutment may be provided to engage the fingers of the other end of the locking ring, the intermediate element, and element of the abutment being generally conical to ensure that the fingers move uniformly outwardly to provide efficient grip of the inside surface of the opening.

The end of the elongate element may have a polygonal formation adapted to be engaged with a tool having a corresponding shaped recess.

For example, the element may have a generally square end, and the tool may have a polygonal formation adapted to engage with a further tool such as a torque wrench, to facilitate rotation of the elongate element to cause the relative rotation between the locking part and the elongate element.

The elongate element may comprise a rod of a wall tie in which case the opening may be provided in an inner or outer wall of a cavity wall structure, the rod extending through a bore in the outer or inner wall of the structure and thraugh the cavity therebetween, into the opening in the inner or outer wall.

The opposite end of the rod in the bore in the outer or inner wall may be secured relative to the outer or inner wall via a further locking ring trapped between a further abutment of the rod and a still further locking part, the further locking ring (or rings) having a finger ar fingers which extend radially outwardly of the axis of the rod, the fingers being urged outwardly into engagement with an inside surface of the opening as the separation between the further locking part and the abutment is reduced.

The locking ring at the other end of the rod may be similar to the locking ring at the innermost end of the rod.

According to a second aspect of the invention,we provide a remedial wall tie having an elongate element comprising a rod, a locking device according to the first aspect of the invention for securing one end of the rod thereof in an opening in the inner or outer wall of a cavity wall structure.

According to a third aspect of the invention, we provide a method of securing an elongate element within an opening in a structure, using a locking device according to the first aspect of the invention, the method comprising the steps of locking the locking part against rotation in the opening by moving the elongate element axially, rotating the elongate element to move the- locking part axially towards the abutment to reduce the separation therebetween and to cause the fingers of the locking ring to move outwardly into engagement with the inside surface of the opening.

In the method according to the third aspect of the invention, the elongate element may be a rod of a wall tie according to the second aspect of the invention.

The invention will now be described with the aid of the accompanying drawings, in which: FIGURE 1 is a section through a cavity wall structure showing an elongate element comprising a wall tie, secured in an opening by a locking device in accordance with the invention, the tie and the locking device being shown partly in section, and partly in elevation; FIGURE 2 is an enlarged perspective view of a locking ring for use in the wall tie of Figure 1.

FIGURE 3 is a perspective view of a locking part and locking member for use with the locking device of Figure 1 prior to assembly, to an enlarged scale.

FIGURE 4 is an end view of the locking member to an enlarged scale.

FIGURE 5 is a side view, to a reduced scale, of a tool for use in for use in fixing the wall tie of figures 1 to 4 in position.

Referring to figure 1 of the drawings, a cavity wall structure 10 comprises an outer wall 11, an inner wall 12 and a cavity 13 therebetween. A bore 14 extends through the outer wall 11, and a continuation of the bore, indicated at 15, provides an opening which extends into the inner wall 12 but is blind, i.e.

has a closed end 16.

It will be seen that the closed end 16 of the opening is conical due to the drill shape by which the opening was provided. Of course, if desired, the bore 14 and/or opening 15 need not be drilled, but could be provided by any other method as desired and the opening 15 may be closed by an abutment in the opening 15 rather than having a closed end 16.

Received within the bore 14 and opening 15 is a wall tie 20 having an elongate element comprising a rod 21, end regions 22 and 23 of which are threaded, the threads extending inwardly of the rod 21 over a distance generally equal to the length of the bore 14 and opening 15 respectively.

However, one end of the rod has a square projection indicated at S.

The wall tie 20 at the end 23 received within the blind opening 15, is shown in section, whereas the end 22 of the wall tie 20 received within bore 14 is shown in elevation.

In each case, the wall 12, 11 is sectioned.

A nut 25 is screwed on the end 23 of the rod 21, and provides part of an abutment 30 of the tie with which one end of a locking ring 31, hereinafter described, co-operates.

The abutment 30 further comprises a generally conical element 27 which tapers from one end 28 which engages the nut 25 to another end 29 which is received within an open end of the locking ring 31. The element 27 has two tapered regions A,B, the taper of region B being of greater angle than the taper of region A.

A female threaded locking part 26 is also received on the threaded end 23 of the rod 21, the locking part abutting an intermediate part 35.

The intermediate part 25 has a shoulder 36 which engages the locking part 26, a projecting portion 37 which is received within another end of locking ring 31, and a generally conical surface 38 between shoulder 36 and portion 37.

The locking ring 31 is thus received on the rod 21, trapped between the abutment 30 and the locking part 26, the ring 31 being shown in detail in Figure 2.

The ring 31 comprises a plurality, in the present example eight, fingers 32 at each end of the locking ring, the fingers 32 being separated from one another by slits 33 which together with the fingers 52, extend generally axially of the rod 21 from the edges 38 of the fingers 32 to an unsplayed cylindrical part 34 of the ring 31.

In use, the ring 31 substantially completely surrounds the rod 21, although as the ring 31 is fabricated from sheet metal, there is a slit 39 extending along the entire length of the ring 31. If the locking ring 31 is fabricated in another manner or made for example moulded in plastics material or drawn from tube, such slit 39 may not be present, or if desired the slit may be closed by adhereing or otherwise permanently securing together the edges of the slit 39.

Each end of the ring 31 receives the end 29 of the element 27 or the end 37 of element 35.

The purpose of the tapered regions A,B, 38, is to ensure that the fingers 32 of the locking ring 31 are urged uniformly outwardly as hereinafter described, to engage inside surface 41 of the opening 15.

Because the locking part 26 and element 35 are separate relative rotation is permitted.

It will be appreciated that as the locking part 26 is rotated relative to rod 21 (in practice rod 21 is rotated relative to locking part 26) that the distance between the abutment 25 and the locking part 26 will decrease, at least in one sense of rotation. This will cause the conical element 27 and intermediate element 35 to be urged together so that the fingers 32 of the locking ring 31, are urged outwardly into abutment with the inside surface 41 of the bore 15. As can be seen from the drawing, the tapers of the regions A,B, of element 27 are of smaller angle than the taper of conical surface 38 of element 35 so that the fingers 32 which co-operate with element 27 tend to be urged outwardly the most.

As the fingers 32 of the locking ring 31 each extend radially outwardly of the axis of the rod 21, a considerable resistive force to withdrawal of the rod 21 from the bore 15 is exerted.

If the material of wall 12 is not too hard, the fingers 30 will cut or dig into the surface of the opening 15. Thus or otherwise a tight frictional grip will be achieved.

In practice, when the wall tie 20 is inserted into the bore 14 and opening 15, as the locking part 26 is then inaccessible, the rod 21 is rotated relative to the locking part 26. This is achieved using the tool shown in Figure 5 engaging the square projection S as hereinafter described.

It will be appreciated that unless the locking part 26 is locked against rotation in the opening 15, the locking part 26 will simply rotate in the opening 15 as the rod 21 is rotated, and thus the distance between the locking part 26 and the abutment 25 will not decrease. Hence a locking member 60 is provided to prevent the locking part 26 rotating.

The locking part 26 and locking member 60 will now be described in detail with reference to figures 3 and 4.

The locking part 26 has a threaded bore 50 to receive the threaded end 23 of rod 21 and a cam outer surface 51 which extends from a smaller diameter region 52 to a larger diameter region 53. In the cam surface 51 and along both of the regions 52,53, is a shallow groove 54 which extends longitudinally of the locking part 26.

As shown, the locking part 26 is solid, but could be provided by a suitable ring if required, although an internal filler such as a sleeve, or an extension of sleeve 43 may be required. The locking member 60 is made of spring steel of generally cylindrical configuration. A pair of slits 61,62, are provided in the member 60, one slit 61 extending throughout the full length of the member 60, whilst the other slit 62 extends only partly along the member 60 from one end 63 in which, in use, the smaller diameter region 52 of the locking part 26 is received.

A pair of cuts 65 are also provided in the end 63, the edges of which are bent outwardly to provide two pairs of sharp ears 66.

More than four ears may be pravided if desired, or less than four, by varying the number of cuts 65.

Further, the end of the slit 61 adjacent end 63 of the member 60 is bent inwardly to provide a tongue 68 which, in use, is received in the groove 54 of the locking part 26 when the locking part 26 and locking member 60 are engaged as shown in figure 1.

Operation of the wall tie 20, and in particular the manner in which it becomes locked in the opening 15, will now be described.

Once the opening 15 has been provided in wall 12, end 23 of the tie 20 is inserted inta the opening 15 through bore 14. At this point, the fingers 32 of the locking ring 31 are a minimum distance from the axis of the rod 21. Their external dimensions may be slightly greater than the internal dimension of the bore 14 opening 15, in which case the locking ring 31 may need to be urged along the bore 14 and into the opening 15 with the aid of a gentle tap with a hammer.

The end 28 of element 37, the shoulder 36 of element 35 as well as the fingers 66 are preferably all a close fit with the opening 15.

In any case, when forward edge 67 of the locking member 60 engages the conical surface 16 of the blind end of the bore 15, a gentle tapping on the square projection 5 of the wall tie, will move the locking part 26 axially, relatively inwardly of the end 63 of the locking member 60 and thus cause the locking member 60 to ride up over the cam surface 51 to move the ears 66 outwardly into abutting engagement with the inside surface 50 of the opening 15.

The locking member 60 thus becomes tightly trapped between the locking part 26 and the inside surface 41 of the opening 15, providing in turn, very tight frictional engagement between the locking part 26 and the locking member 60. Provided that the material in which the opening 15 is provided, is not too hard, the ears 66 of the locking member 60 will dig into the inside surface of the bore 15 to give added resistance to relative rotation between the locking member 60 and the opening 15 when the rod 21 is subjected to rotation.

Thus tapping of the projection S, i.e. moving the rod 21 axially, will secure the locking member 60 relative to the opening 15, and due to the frictional engagement between the cam surface 51 of the locking part 26 and the locking member 60, the locking part 26 will thus become secured against rotation in the opening 15. Further, of course the tongue 68 in the groove 54 of the locking part will prevent rotation occurring between the locking part 26 and locking member 60.

Thereafter, the rod 21 is rotated by engaging the tool 70 shown in figure 5 with the projection S. It can be seen that the tool 70 has a generally square recess 71 to receive projection S. At an opposite end thereof, the tool 70 has a hexagonal projection 72. When the tie 10 is received in the opening 15, the tool 70 is sufficiently long for the projection 72 of the tool to extend from the opening 15.

Thus a torque wrench, spanner, or other suitable tool can be engaged with the projection 72 to rotate the rod 21.

This rotation causes the distance between the abutment 25 and locking part 26 to decrease and hence the element 27 of abutment 25 and element 35 adjacent locking part 26, will be urged towards one another to splay the fingers 32 of locking ring 31 so that the fingers 32 of the locking rings 31 are urged outwardly into increasingly tight abutting engagement with the inside surface 41 of the opening 15 as the rod 21 is rotated.

In practice the fingers 32 adjacent element 27 provide main resistance to withdrawal of the rod 21 because these fingers 32 are urged outwardly the most.

If a withdrawal force is exerted however, the locking ring 31 will remain in position and element 35 may tend to be pulled into tighter engagement with the locking ring 31. This will cause the fingers 32 adjacent element 35 to be urged outwardly further.

Thus the greater the pull out force, the more resistance to withdrawal is exerted by the fingers 32 adjacent element 35.

Preferably a torque wrench is used so that a predetermined torque can be applied to rod 21. It has been found that the pull out force which the tie 10 is able to resist is dependant on the torque applied. Hence the tie 10 can be engaged to resist a predetermined pull-out force, depending of course on the material from which the inner wall 12 is made.

Thus rotation of the rad may be controlled by the torque wrench so that a predetermined deformation of the fingers 32, and a predetermined resistance to pull out, is obtained.

If necessary, a washer may be inserted between the element 35 and the locking part 26, to facilitate relative rotation therebetween as the rod 21 is rotated.

It will be appreciated that the locking member 60, locking ring 31, abutment 25 and the locking part 26, together provide a locking device to ensure that the tie 20 will be firmly locked in the opening 15 against axial withdrawal of the end 23 of the rod 21 from the opening 15.

Preferably, such a wall tie is capable of withstanding a withdrawal force of at least 600 Ibs, and more preferably up to more than 2000 Ibs, provided that the material of the structure in which the opening is provided, is capable of withstanding such withdrawal force.

The end 22 of the rod can be secured relative to wall 11 as follows.

Received on the end 22 of the rod 21 is a further locking ring 31' substantially identical to locking ring 31.

The fingers 32' at one end of the locking ring 31' engage an abutment 75 comprising a element 74, similar to element 27 at the opposite end of the rod 21, and an adjacent nut 75'.

The outer end of the locking ring 31' is engaged with a further female threaded locking part 77 which in turn is engaged with a nut 78 received on the threaded end 22 of the rod 21. Thus, upon rotation of the nut 78, for example with a socket spanner with a torque wrench, the distance between the locking part 77 and the abutment 75 will decrease, again urging the fingers 32 of locking ring 31 outwardly into increasingly tight frictional engagement with the inside surface 80 of the bore 14.

It can be seen that the outermost part 91 of the bore 14 is enlarged to permit insertion of a socket spanner. Alternatively, the nut 78 may be smaller than shown, to permit introduction of a spanner.

Further alternatively, instead of a separate locking part 77 and nut 78, these may together comprise a threaded collar, and the collar may extend beyond the end 22 of the rod 21, the collar having aligned slots in the end thereof to receive a screwdriver bit, for tightening.

The element 74, locking ring 31', locking part 77 and nut 78 may be received on the end 22 of the wall tie 20 once the other end 23 of the wall tie has been secured in the opening 15, although the entire wall tie is preferably fully assembled ready for locking, before the end 23 is inserted through bore 14 into opening 15.

Within the cavity 13, the rod 21 is provided with a rubber grommet 90 or other transversely extending member to cause any moisture accumulating on the wall tie 20 to drip therefrom into the cavity 13, rather than onto the inside surfaces of the walls 11 and 12.

Preferably the rod 21 of the wall tie 20 and the locking device thereof, apart from rubber grommet 90, and locking member 60 are entirely made from a rust resistant material, such as a high grade stainless steel, although any other suitable alloy or material giving adequate strength may be provided. Locking member 60 is preferably made from strong spring steel which may be suitably treated to resist corrosion, although could be made of stainless steel if required.

The wall tie 20 is intended to be used as a remedial wall tie, that is for insertion into existing cavity wall structures where the original wall ties have rusted through or otherwise become damaged.

Many modifications may be made to the wall tie described without departing from the scope of the invention. For example, the groove 54 in the locking part 26 may be omitted if not required, in which case the tongue 68 provided on the locking member 60 will also need to be omitted.

The abutments 25 and 75 need not be provided by nuts and washers as described, although this is the most convenient, but could be provided by outwardly extending integral parts of the rod 21 for examples.

The locking rings 31, 31' need not be of the exact configuration described. For example, differing numbers of fingers 32, 32', may be provided as necessary, and the fingers may be provided with contours to give strength as necessary, rather than being plain as described.

The projection S of the rod 21 need not be square but could be of any other polygonal configuration to engage with a tool. Alternatively, a clamp means may be used to secure the elongate element in the opening 15 or the end 22 may be slotted to receive a screwdriver bit. The inside surface of bore 14 need not be enlarged at 91 as described, but a special tool to engage the flats of the nut 77 may be used which does not require the additional space.

The invention has been described hereinbefore in relation to a locking device for a wall tie. However it will be appreciated that a locking device such as shown at end 23 of the rod 21 may be used to secure any elongate element in an opening/bore.

The device in accordance with the invention for example may be used to secure an elongate element in an opening or bore which has an obstruction therein such as a blind end which prevents the elongate element from passing entirely therethrough.

The device may be used to secure a stud received in an opening in a wall. The locking device may be used where the structure in which the elongate element is received is soft e.g. made of wood or plastic, as the fingers will dig deep into the surface of the opening to provide efficient grip and resistance against withdrawal, whereas, in a harder material such as brick, concrete or masonry generally, or metal, the fingers 32, 32' may dig into the surface of the opening a small amount only, and otherwise rely on frictional force between the fingers 32, 32' and the wall of the opening to provide resistance to withdrawal.

In suitable applications, the fingers the locking ring 31, 31' may extend angularly relative to the axis of the element.

The features disclosed in the foregoing de scription, in the following claims, or the ac company ing drawings, expressed in their spe cific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or compositions, as appropriate, may, separately or in any com bination of such features, be utilised for realis ing the invention in diverse forms thereof.

Claims (30)

1. A locking device for securing an elongate element in an opening, the device comprising an abutment, a locking part, and at least one locking ring, the locking ring being positioned inwardly of the end of the element between the locking part, and the abutment, the locking ring being expandable into engagement with the inside surface of the opening upon relative rotation between the locking part and the elongate element, which reduces the separation between the locking part and the abutment, an expandable locking member being provided to lock the locking part against rotation in the opening, at least the outermost end of the locking part being received in the locking member and the locking part having an outer cam surface which upon the locking part being urged further inwardly of the locking member, causes the locking member to expand outwardly to engage the inside surface of the opening.

2. A device according to claim 1 wherein the end of the elongate element on which the locking part is received, and the locking part itself, have corresponding screw threads.

3. A device according to claim 1 or claim 2 wherein relative rotation between the locking member and locking part is resisted by friction.

4. A device according to claim 1 or claim 2 wherein the locking part and locking member each have co-operating formations which abut and prevent relative rotation occurring.

5. A device according to claim 4 wherein the locking part has an axially extending groove in its outer surface, and the locking member has an inwardly extending tongue which is received in the groove and rides along the groove as the locking part is urged further inwardly of the locking member.

6. A device according to any one of the preceding claims wherein the cam outer surface of the locking part is conical.

7. A device according to claim 6 wherein the locking part has at its outer end a region of constant smaller diameter which extends along the locking part from the end to the smallest diameter end of the conical surface.

8. A device according to claim 7 wherein at its other end the locking part has a region of constant but greater diameter which extends from the innermost end to the larger diameter end of the conical surface.

9. A device according to any one of the preceding claims wherein the locking part comprises a sleeve having a slit which extends along its entire length, to enable the sleeve to expand.

10. A device according to claim 9 where appendant to claim 5 wherein the inwardly extending tongue comprises a deformed part of the periphery of the or another slit.

11. A device according to any one of the preceding claims wherein a slit is provided which extends part way along the length of the sleeve from the end of the sleeve in which the locking part is received.

12. A device according to any one of the preceding claims wherein the locking member has at least one outwardly extending projection.

13. A device according to claim 12 where appendant to claim 9 wherein the locking member has a plurality of outwardly extending projections provided by cuts in the sleeve, the peripheries of the cuts being deformed outwardly to provide a pair of ears for each cut.

14. A device according to claim 13 wherein the cuts comprise axially extending cuts from the end of the locking member in which the locking part is received.

15. A device according to claim 13 or claim 14 wherein the ears are sharp to facilitate engagement and/or digging in to the inside surface of the opening.

16. A device according to any one of the preceding claims wherein the locking member is made of spring steel.

17. A device according to any one of the preceding claims wherein the locking ring of the device has a plurality of fingers extending radially outwardly, which fingers are moved outwardly into engagement with the inside surface of the opening as the locking ring is expanded.

18. A device according to claim 17 wherein the fingers of the locking ring are made of a malleabie material.

19. A device according to claim 1 7 or claim 18 wherein the fingers comprise a splayed end of the locking ring separated by slits cut axially of the ring, the outermost edges of the fingers providing abutment portions which engage the inside surface of the opening.

20. A device according to any one of claims 17 to 19 wherein the locking ring has fingers at each end, the fingers being, in use, urged outwardly as the separation between the abutment and the locking part is reduced.

21. A device according to claim 20 wherein an element is provided intermediate the locking part and the ring to engage one end of the locking ring and an element of the abutment being provided to engage the fingers of the other end of the locking ring, the intermediate element, and element of the abutment being generally conical.

22. A device according to any one of the preceding claims wherein the end of the elongate element remote from the locking device has a polygonal formation adapted to be engaged with a tool having a corresponding shaped recess.

23. A device according to any one of the preceding claims wherein the elongate element comprises a rod of a wall tie, which, in use, extends through a bore in an outer or inner wall of a structure and through a cavity therebetween, into the opening in the inner or outer wall.

24. A device according to claim 13 wherein the opposite end of the rod in the bore in the outer or inner wall is secured relative to the outer or inner wall via a further locking ring trapped between a further abutment of the rod and a still further locking part, the further locking ring (or rings) having a finger or fingers which extend radially outwardly of the axis of the rod, the fingers being urged outwardly into engagement with an inside surface of the opening as the separation between the further locking part and the abutment is reduced.

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

26. A remedial wall tie having an elongate element comprising a rod, a locking device according to any one of claims 1 to 25 for securing one end of the rod thereof in an opening in the inner or outer wall of a cavity wall structure.

27. A remedial wall tie substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

28. A method of securing an elongate element within an opening in a structure, using a locking device according to any one of claims 1 to 25 the method comprising the steps of locking the locking part against rotation in the opening by moving the elongate element axially, rotating the elongate element to move the locking part axially towards the abutment to reduce the separation therebetween and to cause the fingers of the locking ring to move outwardly into engagement with the inside surface of the opening.

29. A method of securing an elongate element within an opening substantially as hereinbefore described with reference to the accompanying drawings.

30. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.