GB2178126A - Wall fastenings - Google Patents

Abstract

A fixing device for fastening loads to cavity walls, includes a backing plate 4 to be disposed within the cavity 17 abutting against the inner surface of said facing panel 18; and locating portion 5,6, whereby the backing plate is positioned by an operator by feeding said backing plate into the cavity through an aperture 20 in the panel 18. The backing plate 4 has threaded holes 7,8 for engagement by screws received in holes drilled in the panel 18. In a preferred embodiment, the device is formed of sheet metal, is provided with means for producing the aperture through which it is to be passed, and is further provided with an insert to plug the aperture and through which the securing means is secured. The locating portion may comprise a length of looped wire or cord. <IMAGE>

Description

SPECIFICATION Fixing device This invention relates to fixing devices for use with cavity walls or ceilings which are adapted to provide support for screws, bolts or other like securing means passing through the panels of such walls.

A cavity wall of the type with which the present invention is primarily concerned generally comprises two panels e.g. of plasterboard supported on studding and separated by a cavity. The panels are generally thin in comparison to the thickness of a solid wall, and are highly unsuitable for bearing loads. A screw, for example screwed directly into one of the panels is only supported around a small portion of its shaft, the end of the shaft protruding into the cavity. This situation is not assisted by use of a "rawlplug" or other proprietary stopping for assisting the seating of screws in masonry.

The loads borne by securing means affixed to walls may be predominantly vertical in nature, or may have to a greater or lesser extent a horizontal component. In the case of generally vertical loads, a screw can only support a small load before the material of the panel surrounding the screw begins to crumble and the seating of the screw becomes loose. In the case of loads in which there is a substantial horizontal component, the screw is easily pulled out because there is insufficient 'grip' around the shaft of the screw and no grip at all around the threaded portion because of the cavity.

In order to overcome this problem and enable a large load to be supported, it is necessary to provide some means of distributing the load over a larger, more substantial area of the cavity wall panel so that the load on the panel in the immediate vicinity of the securing means and hence the tendency of the panel to crumble is reduced.

With the increasing number of plasterboard cavity walls being erected in modern homes and offices, there is a great need for a device which solves this problem.

It is desirable that any such load-distributing means be located within the cavity adjacent to the inner surface of the panel through which the securing means is to pass. However, a further problem in the provision of such means is that the interior of the cavity is not readily accessible from outside, and the cutting of large access holes in the panel is generally not desirable since they must later be patched.

Various solutions to this problem have been proposed, including various kinds of toggle bolt. A spring toggle bolt for example, has a "toggle" which is forced open behind the panel as the bolt is screwed into the panel and abuts the inside surface, thus providing greater support for the bolt shaft over a slightly larger area of panel from the interior of the wall cavity.

Another example is the gravity operated toggle bolt which has a "toggle" comprising a portion which is pivotably attached to the bolt shaft and falls under gravity once the bolt has been pushed sufficiently far into the wall, such that it hangs parallel to the wall. Screwing of the bolt then causes the toggle to be brought to a position abutting the inner surface of the panel. With both types of toggle bolt mentioned above the strength of any fixing is limited by the size of the hole itself, and the support provided thereby is not always adequate for the task, particularly where the fixing of furniture is concerned.Further disadvantages include the fact that if the bolt is overtightened, it tends to draw that portion of the toggle nearest the shank of the bolt out through the hole, thus damaging the panel, and the fact that the portion of the toggle that abuts the inner surface of the panel often comprises the two edges of a U-shaped toggle and as this is tightened, the edges cut into the panel damaging it also. We have found in our tests with these and other proposals that substantial inflexibility of the backing plate when the screw or bolt is thoroughly tightened is extremely important.

We have now devised a fixing device which can readily be inserted into a cavity wall of the type we are considering and which provides a far more robust fixing than has previously been possible, especially when supporting heavy furniture.

According to the invention there is provided a fixing device adapted in use to provide support for and cooperate with a screw, bolt or other like securing means passing through a facing panel of a cavity wall or ceiling, said device including a substantially inflexible backing plate portion, to be disposed in use within the cavity parallel to and abutting against a portion of the inner surface of said facing panel in the region of said securing means, and locating means extending from the backing plate portion, whereby in use the backing plate portion is positioned by an operator from the facing side of the panel by holding said locating means and feeding said backing plate portion into the cavity through an aperture in the panel and locating it in a desired position for cooperation with said securing means.

Preferably, said securing means comprises a screw, threaded screw or bolt, and said backing plate portion is provided with a hole or holes, threaded if desired for receiving said screw or bolt.

Preferably, in one embodiment, the backing plate will be generally planar and the aperture in the shape of a corresponding slot.

The backing plate portion may be provided with a plurality of said threaded holes whereby the fixing device may be used to support a number of said bolts or screws.

The arrangement of the holes will depend upon the desired use. Clearly, the number of screws or bolts which the device may adequately support is limited by the size of the backing plate portion. The backing plate portion may be held in position by said bolts or screws or provided with other means for holding it in position.

In accordance with one embodiment of the invention, the locating means comprises a locating portion adapted in use to be disposed parallel and adjacent to the outer surface of said panel, and a neck portion joining said locating portion and said backing plate portion and extending perpendicularly thereto. If the backing plate portion is provided with holes which are located in use behind the panel, the locating portion serves as a useful guide to the positions of the holes which are not themselves visible.

In accordance with a preferred embodiment of the invention, the locating means is frangible from the backing plate portion, whereby the locating means may be detached from the backing plate portion after said backing plate portion has been secured in its desired position. The locating means may comprise a portion extending in use perpendicularly from one edge of the backing plate portion. Alternatively it may comprise a portion formed in the same plane as and extending out of the backing plate portion and which is adapted to be bent by the user into a desired position for location. Such bending may be achieved by a user either before the backing plate portion is fed through the aperture or afterwards. In this latter situation, wire, cord or like means may be used to assist in bending the locating means relative to the backing plate when the backing plate is behind the facing panel.The bend between the backing plate portion and the extending portion preferably is weakened so that repeated flexing thereof will ultimately cause the locating portion to break free from the backing plate portion when it is no longer required.

The device as described above is preferably fabricated from a single piece of sheet metal, suitably cut or formed and, where appropriate, bent to shape.

However, in another embodiment, the locating means and backing plate portion may be separately fabricated and the backing plate includes means for temporarily attaching thereto the locating means whilst location occurs.

Such an embodiment might comprise, for example locating means in the form of a pair of tongs adapted to cooperate for location with mating means on the backing plate and which can be removed once location and securing have been effected.

In accordance with a further preferred feature of the invention said backing plate portion is provided with a plurality of threaded holes to be located opposite said slot in use, and the device additionally includes a discrete insert member which may be retained within the slot and through which the securing means will generally pass. Such a member adds yet further to the strength of the assembly. Said insert member may either comprise a base portion and two side portions, said base portion being provided either with holes for registering with respective ones of the holes in the backing plate portion, or with projections which may be urged into the respective ones of the holes in the backing plate, or may be substantially solid either with or without said projections or holes.In either case, the insert member may be screwed, bolted or forcefitted to said backing plate portion, thereby securing said backing plate portion in position.

The insert member may be retained in the slot by means of a number of tabs which extend outwardly from said side portions and abut against the outer surface of the panel in use, and thereby prevent the insert member from being pushed into said cavity. Alternatively, the insert member may completely line the slot and be provided with an outwardly directed flange extending around the circumference thereof.

Preferably, the insert member and backing plate portion are each provided with three holes to be positioned in a row along the slot.

The two outer holes may receive screws for securing the insert member to the backing plate portion, and the central hole may receive the securing means for which the device is to provide support. The device then provides a particularly sturdy support and is also versatile.

It is of course possible to avoid having to cut a slot if a narrower, more elongate type of backing plate is employed. With an appro priate choice of dimensions, a simple substan tially circular aperture may be all that is re quired, and this can readily be provided using a drill or other means. In all the foregoing embodiments, the preferred backing plate ma serial is sheet metal, shaped or formed as ap propriate.

In accordance with a yet further highly pre ferred feature of the invention, the backing plate portion is provided in the form of an elongate generally 'U'-shaped element having a flattened base, the flattened base of the 'U' being the portion intended to abut the inner surface of the panel. Such a construction has great rigidity, especially when formed, as is desirable, from sheet metal which is of the order of about 0.1 cm in thickness or more.

Such a backing plate may be provided with one or more threaded holes for cooperation with corresponding threaded screws and may further be, and preferably is, provided with a discrete insert member in the form of a circu lar bush e.g. of metal or plastic provided also with an aperture through which securing means may pass. The combination will be provided with locating means which may either be in the form of a loop of wire, nylon or cord passing through small apertures in the backing plate and, preferably, the insert, or may be a conventional type of ratchet connector which also passes through both the backing plate and insert, a corresponding tongue for the ratchet being provided in the insert.

Further refinements in such an embodiment may include the provision of means to enable the backing plate itself to produce the desired aperture in the hands of an operator. This may take the form of a sharpened point or points and edge at one end of the elongate backing plate to enable the aperture in the panel to be formed by a twisting movement of the backing plate itself, thus obviating the need for any form of drill. Apertures may also be provided in the side arms of the 'U' shape at the end of the backing plate remote from the sharpened portion to accomodate a temporary handle so as to facilitate screwing out the aperture. The threaded screw itself could be used for this purpose though any other bar or rod of reasonable length and diameter could be used.

The advantages of a device as described immediately above will be evident. If the fixing is to be adequately strong, a backing plate of reasonable thickness and inflexibility will generally necessitate an aperture of at least 8 mm and more preferably at least 12 mm (about half an inch). Not many do-it-yourself enthusiasts possess a drill bit or even a suitable chuck for this size of aperture and so by providing the backing plate with its own 'selfcontained' aperture-cutting means, this problem is avoided. Use of the generally 'U'shaped backing plate most preferably made of metal and provided with one or more threaded apertures enables accurate positioning and thoroughly robust fixing.In addition, if the aperture in the insert through which the securing means passes is eccentrically mounted, a fine adjustment of the exact position of the aperture for securing is provided which can be of great benefit to the operator.

According to a further aspect of the invention we provide a method of situating a fixing device in a facing panel of a cavity wall or ceiling which comprises providing an aperture in said facing panel sufficient to enable the passage therethrough of a backing plate portion of said fixing device that it is desired to dispose within the cavity parallel to and abutting against the inner surface of said facing panel, and passing through said aperture in said panel and locating in a desired position the backing plate portion of said fixing device with which securing means can cooperate.

Such a method allows for the possibility that, according to a further embodiment, a backing plate portion alone may be fed through the aperture, whether in slot or circular form, and held and located by a loop of wire, cord, nylon or like holding means before securing means and optionaily, but preferably, insert means, is introduced.

A further aspect of this invention comprises a kit which includes a backing plate, and securing means. An alternative aspect comprises a kit which includes a backing plate and an insert of the type hereinbefore described, with or without securing means. Either of the above kits may include instructions for use and may include locating means or may make provision for these to be provided by the user.

Certain embodiments of the invention will now be described in detail by way of example only and with reference to the accompanying drawings in which: Figure 1 is a perspective view of a fixing device according to a first embodiment of the present invention.

Figure 2 is a perspective view showing the fixing device of Fig. 1 about to be inserted into a slot in a facing panel of a cavity wall of the type herein described.

Figure 3 is a perspective view showing the fixing device of Fig. 1 positioned in the wall cavity, after having been fed into the slot.

Figure 4 is a perspective view showing the fixing device of Fig. 1 positioned in the wall cavity ready for securing means to be fixed thereto.

Figure 5 is a cross-sectional view taken along line V-V in Fig. 3.

Figured is a front elevation showing a furniture wall-mounting bar ready to be secured in position using two such fixing devices.

Figure 7 is a perspective view of one end of the mounting bar after having been secured in position.

Figure 8 is a plan view of the backing member of a fixing device according to a second embodiment of the present invention.

Figure 9 is a front elevational view of the insert member of a fixing device according to the embodiment of Fig. 8.

Figure 10 is a perspective view, partly cut away showing the backing member and the insert member of Figs. 8 and 9 respectively positioned in the wall cavity.

Figure ii is a cross-sectional view taken along the line Xl-Xl in Fig. 10.

Figures 12a and 12b are perspective views alternative forms of insert member for the embodiment of the invention shown in Figs. 8 to 11.

Figure 13 illustrates an alternative embodiment of the invention, which uses the backing member of Fig. 8.

Figures 14 shows an exploded perspective view of an embodiment in which a backing member is located using wire, cord or similar holding means.

Figure 15a shows in perspective an alterna tive form of backing plate member.

Figure 15b shows a cross-sectional exploded view of the fixing of an item to a wall using a backing member shown in Fig. 15a.

Figure 16a shows an exploded perspective view of a further alternative form of device.

Figure 16b shows the device of Fig. 1 6a in assembled form in cross-section.

Figure 17 shows a schematic cross-section of a yet further alternative form of device.

Figs. 1 to 5 illustrate a fixing device constructed in accordance with a first embodiment of the present invention. The device illustrated and generally designated 1 is particularly adapted for use in fixing a mounting bar 2 (Figs. 6 and 7) to a plasterboard cavity wall 3. However, it will be understood that devices of this nature could be adapted for fixing a wide variety of articles to cavity walls or ceilings, such as wooden battens, shelving, pictures, wall brackets, electrical switch gear, wiring runs, ceiling roses and a host of other items.

Such mounting bars 2 are frequently used in mounting cabinets and shelves on walls, and are known in the art. The fixing device 1 comprises a backing plate portion 4, and locating means comprising a neck portion 5 and a locating portion 6. As can be seen from Fig.

1, the locating portion and the backing plate portion comprise flat metal plates which are oriented in substantially parallel planes. The neck portion comprises a further metal plate which joins the backing plate portion and the locating portion at their edges, and is oriented substantially perpendicular thereto. The device is preferably made from a single sheet of metal, suitably cut and bent. A pair of threaded holes 7, 8 are provided in the backing plate portion, whose function will be described hereinafter.

The mounting bar 2 comprises an elongate bar 10, having two mounting brackets 11, 12 affixed thereto for example by welding. The bar and brackets are again preferably formed from sheet metal. Each mounting bracket has two holes 13, 14, 15, 16 formed therethrough, in the region where the bracket is fixed to the bar. These holes pass through the bar 10 as well. As can be seen from Fig. 6, the brackets are substantially rectangular and their longer edges are disposed substantially perpendicularly to the longer edges of the bar.

Of the four holes in the brackets, the two which are disposed to the left of the brackets as viewed in Fig. 6, namely 13 and 15, are circular whilst the other two 14, 16 are slots.

For reasons which will later become clear, the two holes 7, 8 in the backing plate portion 4 of the fixing device 1 are positioned so that when the backing plate of the fixing device is placed behind one of the brackets 11, with the locating portion positioned right in the cor ner between the bracket and the bar, as viewed in Fig. 6, the hole 8 is aligned with circular hole 13 and the hole 7 is aligned with the lower portion of slot 14.

Fig. 6 shows the mounting bar 2 ready to be fixed to a cavity wall 3 using two fixing devices, 1 and 1'. The mounting bar is fixed to the wall with the aid of the two fixing devices as follows: Firstly, the mounting bar is offered up to the wall and held in the desired position. The locations of the holes 13, 14, 15 16 are marked on the wall, together with the positions of the lower edge of the bar 10 and the left hand edges of the brackets 11, 12 as viewed in Fig. 6. The mounting bar may then be put down. Next, a fixing device 1 is positioned on the wall with the holes 7, 8 aligned with the marked positions of the holes 13, 14 and the exact positions of the holes are marked on the wall. This step is necessary since the diameter of the holes 7, 8 is slightly less than the diameter of the holes 13, 14.The fixing device is then put down and holes are drilled through the panel 18 of the cavity walls at the marked positions of the holes 7, 8. A second fixing device 1' is then positioned on the wall with its holes 7', 8' aligned with the marked positions of the holes 15, 16 and the procedure is repeated.

Next, a horizontaliy elongate slot 20 is cut in the panel 18 through which the backing plate portion 4 of the fixing device 1 may pass. The thickness of the slot 20 should be equal to the width a of the neck portion and the upper edge of the slot 20 should be aligned with the marked position of the lower edge of the bar. The left hand vertical edge of the slot 20 should be located slightly to the left of the marked left hand vertical edge of the bracket 11 by an amount equal to the thickness of the metal from which device 1 is made. The width of the slot 20 should be equal to the maximum wdth of the backing plate portion 10, or preferably slightly larger for ease of movement.

The backing plate portion of the fixing device is then fed into the wall cavity 17 through the slot 20 whilst holding the locating portion, to a position in which the backing plate portion and the locating portion lie parallel to the surface of the panel 18 and the neck portion passes through the slot as shown in Fig. 3. The locating portion is then moved to the left as shown by the arrow in Fig. 3 until the neck portion abuts the left hand vertical edge of the slot 20. The device is then rotated through an angle of approximately 90" about the neck portion to the position shown in Fig. 4. Here, the neck portion lies flat against the left hand vertical edge of the slot 20. In this position, the holes 7, 8 register with the holes which have been drilled through the panel 18, and the fixing device is positioned ready to receive screws which are to secure the mounting bar 2 to the wall.

The procedure described above is repeated with the second fixing device 1', cutting a slot through which backing plate portion 4' may pass, the left hand vertical edge of the slot being located slightly to the left of the marked left hand edge of the bracket 12.

The mounting bar may then be secured to the wall using screws which pass through the holes 13, 14, 15, 16 in the brackets, through the drilled holes in the panel 18 and through the threaded holes 7, 8, 7', 8' in the backing plate portions 4, 4' of the fixing devices 1, 1'.

As the screws are tightened, the backing plate portions are pulled against the inner surface of the panel 15 and thus the backing plate portions 4, 4' of the fixing devices 1, 1' serve to strengthen the portion of the panel surrounding the screws which support the mounting bar 2. This helps to prevent the plasterboard from crumbling under the load supported by the mounting bar. Moreover, the final appearance of the mounting is neat, since the slots are covered by the brackets of the mounting bar 2, and the only portion of the fixing device which is visible is the locating portion 6.

Suitable dimensions for the device are as follows: a=width of neck portion=6.5 mm b=width of backing plate portion =53 mm c=depth of backing plate portion =45 mm d=length of neck portion thickness of plas terboard panel and any surface plaster work=15 mm e=depth of locating portion =20 mm f=width of locating portion= 16 mm.

It will be appreciated that these dimensions can be altered to suit different circumstances.

Clearly, fixing devices such as that described above may be used to mount a variety of articles to cavity walls, the only requirement being that the threaded holes in the backing plate portion be so positioned that they register with the desired positions of the screws which are to pass through panel of the cavity wall.

A second embodiment of the invention is illustrated in Figs. 8 to 11. This embodiment is extremely versatile in that the device is not specially adapted for any desired function and may be used for a variety of applications.

The fixing device consists of two discrete members, a backing member 31, illustrated in Fig. 8, and an insert member 32, illustrated in Fig. 9. The backing member 31 comprises a backing plate portion 33, and locating means comprising a neck portion 34 and a locating portion 35. Preferably the backing member 31 comprises and may be stamped out of a single piece of sheet metal. The backing plate portion 33 is generally rectangular, whilst the locating portion and the neck portion form a T-shape which extends from one edge of the backing plate portion. As shown, the backing plate portion is ready for use, with the plane of the backing plate portion oriented perpendicularly to that of the locating portion and neck portion. However, it is preferably provided in a flat form.For reasons which will be described hereinafter, the bend between the neck and backing plate portions is weakened so that repeated flexing of the bend will cause the neck portion to break away from the backing plate portion when it is no longer required. A number of drilled holes 41, 42, 43 are provided in the locating portion 35 and a number of threaded holes 44, 45, 46 are provided in the backing plate portion 33. Preferably, the hole 45 is larger than holes 44, 46 which are identical in diameter.

The insert member 32 in one embodiment is generally U-shaped in cross-section, as can be clearly seen from Fig. 10, and comprises side portions 36, 37 and a base portion 38.

The side portions include extensions 36a, 37a which carry tabs 40 at their edges. The tabs extend perpendicularly from the side portions 36, 37 and outwardly from the base portion 38. Three drilled holes 47, 48, 49 are pm vided in the base portion 38 of the insert member 32. The spacing between the holes corresponds to the spacing between the holes 44, 45, 46 in the backing plate portion of the backing member 32.

The fixing device according to this embodiment of the invention is simply adapted to provide support for a single screw which its to pass through a panel of a cavity wall. Thus if a cupboard, for example, is to be screwed to a cavity wall, one fixing device will be provided for each of the screws required.

The fixing device is used as follows. First, the desired position of the screw is marked on the wall. The backing member 31 is then placed against the wall with the hole 42 registering with the marked desired position of the screw and with the locating member oriented substantially horizontally. The positions of the holes 41, 42, 43 and the outline of the locating portion are then marked on the wall after which the backing member may be removed.

Next, a linear slot 50 is cut through the panel 18 of the cavity wall corresponding to the marked position of the locating portion 35.

This is preferably achieved by drilling holes at the marked positions of the holes 41, 42, 43 and then cutting a slot along the line of the holes. For this purpose, the backing plate portion or locating portion might be provided with a serrated edge or other means for use in this cutting and aperture-producing operation.

If necessary, the backing portion is now bent so that the neck portion and backing plate portion are oriented substantially perpendicularly. The backing member is then held by the locating portion, and the backing plate portion is fed into the cavity through the slot 50 and tilted to a position in which the backing plate portion is parallel to the wall. The locating portion is then moved sidewardly until the neck portion abuts against one vertical edge of the slot 50, and turned through approximately 90 so that the neck portion lies flat against one of the vertical edges of the slot 50, and the backing plate portion covers the slot from behind, as shown in Fig. 8.

Next, whilst holding the backing member in position, the insert member is pushed into the slot 50, base portion first, until the tabs 40 abut against the front surface of the panel 18 and further movement of the insert back into the slot is thereby prevented. The insert member is pushed sidewardly if necessary until the holes 47, 48, 49 in the insert member are aligned with respective ones of the holes 44, 45, 46 in the backing member.

The insert member will desirably be a snug fit within the slot and this should be borne in mind when cutting out the slot.

The insert member is next secured to the backing member by screwing a suitably sized threaded bolt 51 through the hole 45 in the backing member via the hole 48 in the insert member. The insert member is then held to the backing member by the head of the bolt.

Next, further screws 52, 53 are screwed into the threaded holes 44, 46 through respective ones of the holes 47 and 49 to firmly secure the insert member and the backing member in place.

The locating portion and neck portion of the backing member are then no longer required, and by flexing the bend between the neck portion and the edge of the backing plate portion as mentioned above, the neck portion and locating portion are broken free. The central bolt 51 may now be unscrewed, the insert and backing member remaining held in place by the other two bolts. Thus, the central bolt 51 may be used for securing an article to the cavity wall, it being firmly supported from behind by the backing plate portion.

The fixing device according to this embodiment of the invention is especially versatile since it can be used to hang almost any article on a cavity wall without any necessary modifications. If it is necessary to screw screws into the wall so closely together that it is not possible to provide one such fixing device for each screw, further threaded holes such as 55, 56, 57, 58 shown in the drawings could be provided in the backing plate portion for receiving screws passing through the panel in the region surrounding the slot.

Using a fixing device according to the present invention, it is possible to distribute the outward-pulling component of any load on the wall over a very large area thereof, depending on the size of the backing plate portion.

A further advantage of this embodiment of the invention is the fact that the slot is partially lined by the extensions of the metal side portions 36a, 37a of the insert and thus portions of the sides of the slot are prevented from crumbling. The insert member may alternatively be formed so as to entirely line the slot. This then protects all the sides of the slot from crumbling. The tabs 40 might be replaced by an outwardly directed flange extending from the side portions 36, 37.

A further advantage of the device is the fact that when in position it lies flush with the surface of the cavity wall panel. Thus not only gives a neat outward appearance, but also it means that the device does not obstruct the positioning of an article to be hung on the wall.

A yet further advantage of this embodiment is that with the insert member snugly fitting in the slot and secured to the backing member, any loading is more evenly distributed. A mainly vertical loading in particular, such as might be present when hanging heavy articles such as pictures, flower baskets, mirrors and the like, is more evenly distributed. This latter advantage clearly decreases if the slot is other than horizontal.

In order to further strengthen the fixing device, the backing plate portion might be provided with a number of ribs extending across its surface.

Suitable dimensions for the backing portion 31 are as follows: Width of backing plate portion 33=length of backing plate portion=50 mm.

Width of neck portion 34=7 mm.

Length of locating portion 35=48 mm.

Width of location portion =6 mm.

Diameter of hole 45=4 mm.

Diameter of holes 44, 46=3 mm.

Diameter of holes 41, 42, 43=3 mm.

Suitable dimensions for the insert member 32 are as follows: Length of base portion =34 mm.

Width of base portion=7 mm.

Depth of insert member from base portion to tabs=8.5 mm.

Diameter of hole 48=5 mm.

Diameter of holes 47, 49=42 mm.

The backing member and insert member are preferably fabricated from metal plate having a thickness of 1 mm, though other suitably robust materials may be used to suit varying circumstances.

Fig. 12a illustrates an alternative form of insert member which may be used in conjunction with the backing member 31. This insert member 60 comprises a body portion 61 formed e.g. from a plastics material as a onepiece moulding, and two plastics pegs 62, 63 which may be separate from or integrally formed with the body portion and which extend from holes 64, 65 in the body portion 61. The pegs are adapted to be received in the holes 52, 53 in the backing plate portion and are serrated so that once they have entered the holes they cannot be drawn out. As can be seen most clearly from Fig. 12, the body portion has a narrowed central portion having a hole 66 passing therethrough. The hole 66 is adapted to receive the central bolt 51. The 2 portions of the body portion which receive the pegs 64, 65 are each provided with an outwardly directed lip 67, 68.In use, this lip abuts against the surface of the wall panel and prevents the insert from being pushed into the wall cavity.

This form of insert member is easier to use than that previously described since once the backing member has been positioned as desired in the cavity, it simply needs to be held in place whilst the insert member is pushed or hammered in the slot so that the pegs 62, 63 enter the holes 52, 53 in the backing plate portion. If necessary, the insert member body and the backing plate portion may be drawn closer together using the bolt 51. If the pegs are separately formed, they will be prevented from being pushed into the body portion by the surfaces of the serrations 70 shown in Fig. 1 2a abutting against the body portion.

After they are firmly secured together, the bolt 51 may be removed and used as securing means for an article to be hung on the wall.

Fig. 1 2b shows an alternative form of insert member which is identical to that of Fig. 12a except that is is not provided with pegs 62, 63. This insert member may be secured to the backing member by means of screws passing through the holes 64, 65, in a similar manner to the securing of the insert member 32 of Fig. 9.

Using the first form of the insert member shown in Fig. 9, it is possible for the two outer holes 47, 49 to be used to receive securing screws for an article to be hung on the wall, with the bolt 51 serving to hold the insert member and the backing plate portion in place.

The same is possible using the plastics insert member shown in Fig. 12a. The insert member 60 may be held in place using the central bolt 51, and screws for securing an article to the cavity wall may be screwed into the holes 64, 65. If the pegs were integral with the body they would have to be first drilled out. If they were separately formed, they could simply be displaced as screws were screwed into the holes 64, 65 so that they fell into the cavity.

Clearly the same is also possible using the insert member shown in Fig. 12b.

Thus with suitably spaced holes 47 and 49 or 64 and 65, the device according to the second embodiment of the invention may also be used to secure the mounting bar 2 to a wall. Alternatively, a pair of such devices may be employed to secure a simple wooden batten or a range of similar items to a wall such as in the case where, for example, a shelf is being put up.

A further embodiment of the invention is shown in Fig. 13. In this embodiment, a device of the type described in Figs. 8, 10 and 11 is pushed through a slot 80 and then bent in situ. The bending of the neck portion 34 relative to the backing plate portion 33 is achieved by pulling on a length of looped wire 81 which, in cojunction with a point of weakening at the junction of the backing plate and neck portion, is adequate for the purpose.

This embodiment is of particular value in providing a fixing device for use with thicker, double- or more -skinned cavity walls such as are occasionally required for fire regulations. It will be appreciated that a bent device will be harder to insert when the panel is thicker unless the slot is made bigger, which is generally undesirable. Furthermore, in this embodiment, the slot 80 can be made much thinner, only just larger than the backing plate and this would enable the securing means to grip to an extent upon the panel material also, thus avoiding the need for an insert member.

It is also possible to do away with the need for a fixed or frangible locating portion. A backing plate portion alone may pushed through the slot and retained using a length of wire, cord, line or similar means threaded through the two holes 46 and 44. Once the plate is completely within the cavity it can be rotated and pulling on the wire will cause the backing plate portion to abut against and be oriented parallel to the panel with the holes registering with the slot. In embodiments which work on this principle, the wire or cord acts as a type of locating portion alone.

Fig. 14 shows an embodiment of the invention in which a fixed or frangible locating portion is dispensed with. The device according to this embodiment comprises a backing plate portion 100 having three holes 101, 102, 103 formed therethrough. Hole 102 is preferably threaded whilst holes 101 and 103 are plain.

Additional holes may be provided if required.

An insert member 110 for this embodiment is fabricated as a one-piece moulding and includes a body portion 111 provided with a thickened, generally cylindrical central portion 112 through which a hole 113 passess. The central portion is provided with an outwardly directed flange 115. Each end of the body portion is provided with a peg 120, having a serrated shaft, formed integrally with the body portion. The pegs are similar to the pegs 62, 63 of the insert member shown in Fig. 12a.

This embodiment of the invention is used as follows. Firstly, a loop of wire or nylon twine 130 is threaded through the two holes 101 and 103. Next, a slot 140 is cut in the facing panel of the cavity wall, the slot being shaped so as to allow the passage therethrough of the backing plate portion 100 and to enable the insertion therein of the insert member 110. However, it should be noted that since no locating portion is required for this device, the slot and hence the insert member may be made narrower than in the previously described embodiments. The backing plate portion is fed into the slot whilst holding onto the loop of wire 130 until it drops into the cavity. By simply pulling on the wire 130 the backing plate portion may be brought to its desired position behind the slot.A bolt 125 is passed through the hole 133 in the insert member, and whilst holding onto the wire to maintain the backing plate portion in position, the insert member 110 is offered up to the slot 140 such that the bolt 125 registers with the threaded hole 102, and the bolt 125 is then tightened. This will cause the pegs 120 to be forced into the holes 103, 101 in the backing plate portion. The insert member 110 is prevented from passing into the cavity by a flange 115 which abuts against the facing surface of the panel of the cavity wall. When the bolt 125 has been so tightened that the flange 115 abuts against the facing surface of the panel, and the backing plate portion 100 abuts against the inner surface, the bolt 125 may be removed.The insert member and the backing plate portion will be held together by the pegs 120 and the bolt may then be used, as before, to secure an article to the wall. The wire may be cut off and discarded.

In order to facilitate the insertion of the insert member into the slot, the body portion of the insert member including the central thickened portion is preferably tapered in cross section.

As with the insert member shown in Figs.

12 and 12a, the insert member of this embodiment may be provided without pegs and be adapted to be fixed to the backing plate portion by means of screws.

A simple embodiment of the invention which requires neither insert member nor locating portion is shown in Figs. 15a and 15b.

This consists of a backing plate portion 150 which is of elongate rectangular form, with a loop of wire, cord or the like 151 passing through holes 152, 153 either side of and near to a threaded fixing hole 156.

In this embodiment, the backing plate portion 150 is passed either through a hole 160 drilled in the panel equal in diameter to its narrowest dimension, or a slot of like length.

Tension is maintained on the wire 151 until an item 170 to be fixed to the wall is fixed by means of a bolt 173, passing through it and the hole 154 in the backing plate portion.

Clearly this embodiment is only seriously applicable in situations where the force of the load on the bolt is substantially horizontal and outward, and not in situations in which the force of the load on the bolt is substantially vertically downwards.

A further preferred embodiment of the invention is shown in Figs. 16a and 16b. Fig.

1 6a shows an exploded view of a device comprising a flattened 'U-shaped' elongate backing plate portion 200 formed of metal approx. 1 mm thick. At one end thereof, apertures 201 and 202 are provided for insertion of a temporary handle to enable facile twisting of the device around its elongate axis. At the other end thereof, the device tapers to a sharpened end and is provided with a sharpened drilling or gouging portion 203 for penetrating the panel to which the fixing is to be made. It will be realised that this embodiment is of particular application to fixings on panels of softer material, e.g. plasterboard or softboard.

A threaded aperture 204 is provided in the backing plate portion for engagement with a threaded screw 205. An insert 206, is generally cylindrical and formed of plastic or other generally non-resilient material as has a diameter approximately the same or slightly larger than the width of the backing plate portion. The insert has an aperture 207 eccentrically passing therethrough for the threaded screw. Narrow slots 208, 209 are formed in the backing plate portion and insert respectively for locating means 210 in the form of a plastic or nylon ratchet strip, having a retaining flange 211 at one end for situation behind and within the backing plate portion.

Fig. 16b shows the embodiment of Fig. 16a prior to final tightening up. To produce such a fixing, the threaded screw 205 or other rodlike element is inserted through apertures 201 and 202 to provide twisting purchase and point 203 and the sharpened end are twisted and pushed sufficiently far through the panel to provide an aperture of similar dimension to the width of the backing plate.

The backing plate portion is then withdrawn, the ratchet strip 210 is passed through slot 208 in the backing plate so as to be retained thereby and is then further passed through the insert 206 so that apertures 204 and 207 for the threaded screw 205 are aligned. The insert 206 is pushed down the ratchet strip and the threaded screw 205 passed through aperture 207 and partially screwed into aperture 204. The insert is then pushed into the aperture in the panel, where it should fit fairly snugly, and the threaded screw tightened. As a last step, the surplus locating means is cut off. The threaded screw may be removed if desired, since the backing plate is retained in position by the portion of the ratchet strip 210 that is retained.

In alternative similar embodiments to those of Figs. 16a and 16b (not shown), the insert and backing plate may be provided with pairs of apertures of different sizes so that the screw size may be varied to suit the load to be borne. Such an embodiment, including a further slight variation is shown in cross-section in Fig. 17. In such a situation, the locating means will desirably be a loop of nylon cord or twine 224 passing through smaller apertures 223 in a sliding, generally tubular pin 220 adapted to move within an aperture 221 in the insert 222 and anchored to the backing plate in two positions. Different sized apertures for each of differing screws are shown in dotted outline 225, 226. The tubular pin is intended to abut the backing plate and gives accurate alignment of the apertures for the screws in the insert with those in the backing plate.In addition, the tubular pin is formed longer than the depth of the insert to enable use with varying thicknesses of panel.

Assembly is completed by passing a threaded screw through one of the apertures 225 or 226 and screwing it into the corresponding aperture in the backing plate after pulling the backing plate 200 into alignment with the tubular pin 220 using the nylon cord 224. When the fixing is firm, the locating means, whether a nylon ratchet or a nylon loop 224, is then cut off, as is any surplus tubular pin protruding out of the insert. In order to retain the device, one of the screws must stay in the device, though this may be chosen to suit the load.

In all the instances mentioned in the embodiments of the invention described above where threaded holes are provided, drilled plain holes and self-tapping screws may alternatively be used, though these may detract from precise alignment or situation of the backing plates if too much torque is applied to tap the aperture before the assembly is fully tightened.

It is a further advantage in all the embodiments of the invention if the backing plate portion is provided with strengthening ribs.

Claims (16)

1. A fixing device adapted in use to provide support for and cooperate with a screw, bolt or other like securing means passing through a facing panel of a cavity wall or ceiling, said device including a substantially inflexible backing plate portion, to be disposed in use within the cavity parallel to and abutting against a portion of the inner surface of said facing panel in the region of said securing means; and locating means extending from the backing plate portion, whereby in use the backing plate portion is positioned by an operator from the facing side of the panel by holding said locating means and feeding said backing plate portion into the cavity through an aperture in the panel and locating it in a desired position for cooperation with said securing means.

2. A fixing device as claimed in claim 1 wherein the backing plate is generally planar and the aperture in the panel is a slot of corresponding size.

3. A fixing device as claimed in claim 1 wherein the backing platr is generally elongate and the aperture in the panel is substantially circular.

4. A fixing device as claimed in any of claims 1 to 3 wherein the device includes a discrete insert member which in use is retained in the aperture and through which in use the securing means passes.

5. A fixing device as claimed in any of claims 1 to 4 wherein the backing plate portion is provided with means for producing the desired aperture.

6. A fixing device as claimed in any of claims 1 to 5 wherein the backing plate portion is formed of sheet metal.

7. A fixing device as claimed in any of claims 1 to 6 wherein the backing plate portion additionally includes strengthening ribs or side arms for increased inflexibility.

8. A fixing device as claimed in any of claims 2 to 8 wherein the locating portion is frangible from the backing plate portion once the backing plate portion has been secured.

9. A fixing device as claimed in any of claims 3 to 7 wherein the backing plate portion is in the form of an elongate flattened 'Ushaped' member tapered at one end and provided at the tapered end with a sharpened point or points for locating and forming the desired aperture in the panel.

10. A fixing device as claimed in any of claims 3 to 7 and 9 wherein the locating means comprises a loop of wire, cord, nylon or like material or is a ratchet strip adapted to cooperate with a tongue situated in the insert member.

11. A fixing device as claimed in claim 1 substantially as hereinbefore described.

12. A fixing device substantially as hereinbefore described and with reference to any of the accompanying drawings.

13. A fixing device substantially as hereinbefore described and with reference to Figs.

16a and 16b of the accompanying drawings.

14. A method of situating a fixing device in a facing panel of a cavity wall or ceiling which comprises providing an aperture in said facing panel sufficient to enable the passage therethrough of a backing plate portion of said fixing device that it is desired to dispose within the cavity parallel to and abutting against the inner surface of said facing panel, and passing through said aperture in said panel and locating in a desired position the backing plate portion of said fixing device with which securing means can cooperate.

15. A method as claimed in claim 14 substantially as hereinbefore described and with reference to the accompanying drawings.

16. A kit comprising a backing plate portion, securing means and, optionally, an insert for use in combination with locating means in a method as claimed in claim 14 or claim 15.