GB2381035A

GB2381035A - A re-usable fixing device

Info

Publication number: GB2381035A
Application number: GB0206884A
Authority: GB
Inventors: Jeremy Richard Ravenhill
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-10-16
Filing date: 2002-03-23
Publication date: 2003-04-23
Anticipated expiration: 2022-03-23
Also published as: GB2381035B; GB0206884D0

Abstract

This invention relates to a re-usable fixing device, which is intended to fail under a predetermined load condition. The fixing includes a base 10 for attachment to a wall and a load-carrying element 11. In particular the base and load-carrying element have co-operating formations 17,24 for retaining the load-carrying element on the base in normal use and releasing it when a predetermined load is applied to the element.

Description

A Re-usable Fixing Device This invention relates to a re-usable fixing device for failing under predetermined load conditions.

There are many instances where it is desirable to have a fixing which fails, when subjected to a predetermined load or above. This is usually to prevent other more expensive parts of the equipment being broken, but safety considerations are often involved. In many instances the failure occurs by the fracture of an intentionally weak element, which can be replaced. However often this necessitates the use of tools and/or skilled labour.

A very particular need for a fixing device, which will fail in this way, has been identified in institutions where people, who are suicide risks, are housed. People who are intent on suicide, will utilise almost any location as a fixing for a ligature and so the authorities are faced with either providing a completely bare room, which is undesirable for many reasons, or providing fixings for curtain rails, hooks, towel rings, wardrobe rails etc., which will fail, when they experience a load of anything approaching bodyweight. However, it is undesirable that these fixings fail by fracture, because the occurrences may be frequent and fracture often implies sharp edges, which

could be utilised as a weapon or an alternative means of self harm.

Currently the only re-usable fixing available is a magnetic system. This has several disadvantages. First to provide magnets of sufficient strength is expensive and it is difficult to determine how to calculate the separation load. As is well known magnets are much more difficult to separate when force is applied orthogonally to the engaging surfaces, as opposed to when it is applied parallel to the engaging surfaces. Finally the components are made of metal and are readily turned into weapons, which can be used either for self-harm or against members of staff.

The present invention consists in a reusable fixing device for failing under predetermined load conditions

4 including a base for attachment to a wall or the like and a load carrying element characterised in that the base and load carrying element have co-operating formations for retaining the load carrying element on the base in normal use and releasing it when a predetermined load is applied to the element.

In a preferred embodiment the formations are constituted by or include a dome on one of the base or element and an opening for receiving the dome on the other

of the base or element. Depending on the relative dimensions of the dome and the opening the dome will locate and retain the load-carrying element. The dome is preferably resiliently mounted or deflectable.

It is, however, preferred that additionally or alternatively the formations are or constitute or include an open-mouthed channel with inwardly projecting lips on one of the base or element and co-operating flanges on the other of the base or element for introduction into the channel to be retained therein by the lips. The engagement between the lips and the channel, will, when the device also includes the dome, assist in retaining the element on the dome. Where there is no dome, then the retention will be a function of the frictional engagement between the flanges and the lips.

In one construction at least one end of the channel is open, so that the flanges can pass through the open end of the channel when the predetermined load is applied.

In a preferred embodiment the channel has an abutment, which causes the flanges to rotate, when the predetermined load is applied, so that they can pass through the mouth of the channel.

Conveniently the base incorporates the dome and the element has the opening for receiving the dome. Similarly the base may conveniently define an open-mouthed channel with inwardly projecting lips and the element may carry co- operating flanges.

The element may include or define a shaft for carrying a hook, ring or the like and/or may be provided with a screwdriver slot for facilitating its engagement on or removal from the base. In a similar vein, the element can be provided with a lever for assisting such rotation.

The element may define locations for rails. For example, the element may define a socket for one end of a wardrobe rail or, alternatively, it may carry a fixing for a curtain rail at its free end. In the latter case, known attachments often include a pair of flanges for engagement in an open-mouthed channel. It is preferred any such flanges should be dimensioned so that they cannot pass through the mouth of a channel on the base.

Although the invention has been defined above it is to be understood it includes any inventive combination of the features set out above or in the following description.

The invention can be performed in various ways and

specific embodiments will now be described with reference to the accompanying drawings in which: Figure 1 is a front view of a base plate according to one embodiment of the invention; Figure 2 is a view from below of the base plate of Figure 1; Figure 3 is a connecting element for a curtain rail for use with the base plate of Figure 1; Figure 4 is a front view of the connecting element of Figure 3 ; Figure 5 is a view from below of an assembly of a base plate, connecting element and a curtain rail ; Figure 6 is a front view of the assembly of Figure 5 ; Figure 7 is a front view of a hook incorporating a connecting element; Figure 8 is a side view of the hook of Figure 7 ; Figure 9 is a front view of an assembly of the hook and a base plate ; Figures 10 to 12 are corresponding views of a towel ring incorporating the fixing; Figure 13 is a side view of a wardrobe rail ; Figures 14 and 16 and 15 and 17 are respectively side views and end views of the telescopically interconnecting portions of the rail of Figure 13 ; Figures 18 to 21 correspond to Figures 1 to 4 for an alternative embodiment; and

Figures 22 and 23 illustrate a hook version of the alternative embodiment.

As has been indicated above, the fixing device includes a base and a load-carrying element. In Figures 1 to 3 the base is generally indicated at 10 and the loadcarrying element is generally indicated at 11.

As can be seen in Figures 1 and 2, the base comprises a flat plate 12, which is provided with holes for tamper proof fixing screws 13, at its top end, and an open-mouthed channel section, generally indicated at 14, at its lower end. The channel section 14 has inwardly turned in lips 15 to define a mouth 16 and a dome-like projection 17 within the base of the channel between the lips 15. On the lefthand side, the lower end of the lip section of the channel is closed off at 18 to form an abutment 19. The dome 17 may be formed above a recess 20 to allow tne dome 17 to be depressed, when sufficient load is applied. In the particular embodiment the base is an integral moulding and so the surrounding webs act to resiliently return the dome to its operative position. It will be appreciated that the dome could be fixed or otherwise resiliently or deflectably mounted.

Turning to Figures 3 and 4 the load-bearing element

comprises a shaft 21, which has pairs of flanges 22 and 23 at respective ends thereof. The flanges 22, which are at the upper end, as shown in Figure 3, are for fixing into the channel section of a curtain rail in a known manner. The flanges 23 are dimensioned to pass through the mouth 16, when orientated axially within the mouth and to be retained beneath the lips 15 when rotated through 900. A circular opening 24 is defined between the flanges 23 and is dimensioned to receive the dome 17.

In normal use, the base 10 is screwed to the wall of the room or, a wooden mounting or the like by screws 13.

The locking element 11 is then presented to the base 10 with its flanges 23 orientated axially along the mouth 16 so that the dome 17 enters the opening 24. The locking element 11 is then rotated through 90 so that the flanges 23 lie beneath the lips 15 and the left-hand flange engages the abutment 19. In this position the locking element 11 is fixed within the base 10 at a location determined by the dome 17 and it will resist normal attempts to displace it from the base 10.

It will be noted that the flanges 22 are offset by 90 from the flanges 23 and so when the flanges 23 are aligned horizontally, the flanges 22 extend vertically. This can clearly be seen in Figure 6 and in this position the

flanges 22 can locate and support a curtain rail 25, as shown in Figures 5 and 6. It will be understood that in order to achieve this the shaft 21 has to be rotated and conveniently it is provided with flats 26, which can be engaged by a spanner. The flanges 22 are sized so that they will not enter the mouth 16.

Once mounted, the fixing device will, together with similar fixing devices, support a curtain rail in the normal manner, until an excessive load is placed on the curtain rail. An excessive downward force applied to the shaft 21 will both tend to cam the edge of the opening 24 up the dome 17, causing the dome to depress and, because of the presence of the abutment 19 cause the flanges 23 to rotate. At the moment at which they become aligned with the mouth 16, the flanges will pass through the mouth, under the effect of the force, and the locking element 11 will be de-mounted. Hence, if the curtain rail is being used as a ligature point, the curtain rail will come off the wall before the ligature has any damaging effect upon the person, who is trying to commit suicide. It will be noted that because nothing in the device fractures, the curtain rail can easily be returned to its fixed position without any skilled labour and at most the use of a spanner as a tool. As some people will make attempts repeatedly, this can additionally have a cost saving.

When it is to be used in this environment, the locking device is to be made of plastics and, as far as possible, avoid sharp edges so that the occupant of the room is not provided with a weapon. In other context such as students rooms, the device could be suitably formed metal. It will however almost certainly be cheaper to fabricate from plastics material.

It will be appreciated that, depending on the level of the predetermined load, at which the device is intended to separate, various modifications can be contemplated. Thus in the alternative embodiment shown in Figures 18 to 20, there is no abutment; in this case the flanges simply pass through the open end of the channel when the locking element de-mounts from the dome 17. Indeed, in some instances, it may be possible simply to rely on the engagement between the dome 17 and the locking element. In this later embodiment, the bottom of the base 10 is made slightly concave to allow for the depression of the dome 17. However, an alternative approach would be to allow the opening 24 to flex or simply to rely on the opening 24 decamming from the dome 17. It will also be noted in the Figures 18 to 21 embodiment that the flat 26 is replaced with a lever 27.

Turning now to Figures 8 to 9, the base 10 is precisely as previously described. In this case the shaft 21 of the locking element is used to support a hook 28 and at its free end there is a screwdriver slot 29 to enable fixing rotation of the shaft 21. The operation is otherwise as previously described. A corresponding hook arrangement is shown in Figures 22 and 23 utilising the locking element shown in Figures 18 to 20.

Figures 10 to 12 are essentially similar to Figures 7 to 9 except the hook 28 is replaced by a towel ring 30.

In Figures 13 to 17, a wardrobe rail, generally indicated at 31 is made up of two telescopically engageable elements 32 and 33, each of which has locking flanges 23 at its free end. It will be understood that these free ends can readily be engaged in bases 10 located on opposed walls of a wardrobe.

The domes 17, shown in the specification, are all rendered as perfectly hemispherical. It will be understood that this is not necessarily required. What is needed is a raised portion with a suitable camming surface to enable the opening 24 to de-mount from the dome.

Claims

1. A reusable fixing device for failing under predetermined load conditions including a base for attachment to a wall or the like and a load carrying element characterised in that the base and load carrying element have co-operating formations for retaining the load carrying element on the base in normal use and releasing it when a predetermined load is applied to the element.

2. A device as claimed in claim 1 wherein the formations are constituted by or include a dome on one of the base or element and an opening for receiving the dome on the other of the base or element.

3. A device as claimed in Claim 2 wherein the dome is resiliently mounted.

4. A device as claimed in any one of Claims 1 to 3 wherein the formations are, constitute or include an open mouthed-channel with inwardly projecting lips on one of the base or element and co-operating flanges on the other of the base or element for introduction into the channel to be retained therein by the lips.

5. A device as claimed in claim 4 wherein at least one end of the channel is open so that the flanges can pass through the open end of the channel when the predetermined load is applied.

6. A device as claimed in claim 4 wherein the channel has an abutment, which causes the flanges to rotate when the predetermined load is applied so that they can pass through the mouth of the channel.

7. A device as claimed in anyone of the preceding claims wherein the base incorporates a dome and the element has an opening for receiving on the dome.

8. A device as claimed in claim 7 wherein the base defines an open mouthed channel with inwardly projecting lips and the element carries co-operating flanges.

9. A device as claimed in any one of the preceding claims wherein the element includes or defines a shaft for carrying a hook, ring or the like.

10. A device as claimed in claim 9 wherein the element includes a screwdriver slot for facilitating its

engagement or on removal from the base.

11. A device as claimed in any one of the claims 1 to 8 wherein the element defines a socket for a rail.

12. A device as claimed in any one of the preceding claims herein the device is substantially made of plastics material.