GB2474086A

GB2474086A - A cavity fixing device

Info

Publication number: GB2474086A
Application number: GB1000204A
Authority: GB
Inventors: Michael Antony Martin
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-01-07
Filing date: 2010-01-07
Publication date: 2011-04-06
Anticipated expiration: 2030-01-07
Also published as: GB2474086B; GB201000204D0

Abstract

A cavity fixing device comprising a headed bolt element 10 inserted through a first wedge shaped portion (1 Fig. 1) and into screw threaded engagement with a second wedge shaped portion 2. The wedge shaped portions are provided with cooperative planar slide faces (7 8 Fig. 1) which are inclined with respect to the axis of the bolt element 10 and is arranged such that screwing of the bolt element into the second portion causes the two wedges to slide laterally with respect to each other, forcing each portion against the inside face of a cavity wall "A", "B". Ribs (5 Fig. 1) may be provide on the outer surface of the wedge portions to frictionally engage with wall surfaces. A slot 12 is provided in the first portion to allow movement of the bolt. A door frame or window frame may be secured to the fixing device. It is made out of plastic, preferably recycled plastic which is waterproof and ensures the moisture barrier provided by the cavity "C" is not breached.

Description

CAVITY FIXING

TECHNICAL FIELD OF THE INVENTION

This invention relates to the fixing of items such as window and door frames in an aperture in a cavity wall.

BACKGROUND

When fitting a replacement window or door, for example, in a cavity wall, the new window frame is often secured to timber wedges which are cut to shape on site and driven into the cavity in various positions around the aperture. The task of cutting the wedges is time consuming, and there is a risk that if the wedge is even slightly oversize the two skins of the cavity wall will be forced apart necessitating extensive repair and redecoration work. In addition, unless an additional water-proof layer is used, which is frequently omitted, the wedge can act to transmit moisture between the external and internal skins of the wall.

An aim of the present invention may be viewed as being to speed up this operation and, at the same time, reduce the risk of incidental damage to the wall.

A further aim is to reduce the risk of damp transmission across the cavity.

SUMMARY OF THE INVENTION

The present invention proposes a cavity fixing device comprising a headed bolt element inserted through a first portion into screw-threaded engagement with a second portion, and in which the two portions are provided with a pair of mutually co-operable planar slide faces which are inclined with respect to the axis of the bolt element, and the arrangement is such that screwing the bolt element into the second portion causes the two portions to slide laterally with respect to each other.

The first and second portions preferably provide a pair of mutually parallel bearing surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings: Figure 1 is a side view of a cavity fixing device of the invention, shown in a first configuration, Figure 2 is an end view of the cavity fixing, viewed from the left in Fig. 1, and Figure 3 is an axial section through the cavity fixing shown in a second configuration secured in a cavity.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to Fig.s 1 and 2, the cavity fixing comprises first and second wedge elements 1 and 2, conveniently formed of recycled waste plastics material, and each providing a respective bearing face 3 and 4. The two bearing faces are mutually parallel and are each provided with ribs 5 or are otherwise profiled for increased frictional engagement. The two elements 1 and 2 are in mtuaI sliding engagement along a pair ofco-operating planar slide surfaces 7 and B respectively, which are mutually inclined with respect to the bearing surfaces 3 and 4.

A plastics bolt 10 (Fig. 2) having a slotted or similar drive head 11 is passed with slight clearance through a slot 12 formed in the first element 1 to extend perpendicular to the bearing faces 3 and 4. (The axis 13 of the bolt 10 is indicated in Fig. 1.) The outer end of the slot 1 2 is enlarged at 14 so that the head 11 of the bolt 10 is recessed into the first element 1. The shank 15 of the bolt 10 is provided with a coarse thread 1 6 which is screw.engaged in the second wedge element 2. -Referring to Fig. 3, the fixing device is, in use, inserted into a cavity C between wall skins A and B such that the bering surfaces 3 and 4 are generally parallel to the inner faces of the cavity, as shown. The bolt 10 is then screwed into the second element 2 using a suitable screw driver, so that the head 11 urges the first element 1 towards the second 2. This causes mutual sliding contact to take place between the surfaces 7 and 8 until, with sufficient turning of the bolt, the surfaces 3 and 4 come to bear frictionally against the opposite sides of the cavity due to mutual wedging action of the two elements 1 and 2.

Since the device is formed entirely of plastics it is completely waterproof and will not breach the moisture barrier provided by the cavity C. The device can be suitably drilled to receive a fixing screw, e.g. for fixing a window or door frame (not shown) into an aperture in the wall.

It will be appreciated that the second wedge member 2 could instead be drawn with a similar wedging action between a two-part first member 1 upon tightening the bolt 10, so that the two parts of the first member engage opposite sides of the cavity. The important feature of the present invention is the wedging action brought about by the sliding surfaces 3 and 4 which results in relative sliding movement of two bearing surfaces.

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