GB2210569A - A jig assembly - Google Patents

Abstract

The jig (1) comprises a base plate having two major surfaces, one major surface (2) being flat and intended, in use, to be flat against a wall or the like, the second major surface (3) having a plurality of hollow cylindrical tubular members (5, 6, 7) extending substantially perpendicularly thereto, the tubular members (5, 6, 7) being disposed adjacent to one another and corresponding to the outline of a recess to be produced. The array is rectangular e.g. for a switch socket to be drilled out, or circular e.g. for a light socket, here a circular plate has attachable annular plates with tubes for different diameters. <IMAGE>

Description

"A JIG ASSEMBLY" The present invention relates to a jig assembly and, more particularly, to a jig assembly which facilitates the formation of recesses, for example, a wall.

Jig assemblies are, of course, extremely well known.

However, most jig assemblies are utilised to retain a workpiece in a desired location whilst the workpiece is subjected to one or more drilling operations. The thus-drilled workpiece is then utilised in a further manufacturing process.

It is often desired to form recesses in walls or the like to receive, for example, the box portion of an electrical socket. Depending upon the nature of the surface in which the recess is to be formed, the formation of the recess may be both time-consuming and difficult. The simplest way that this may be achieved is by marking the wall in the desired location with the outline of the recess which is to be formed.

The wall is then chiselled out until the appropriately sized recess has been formed. It will be readily apparent that this method is not entirely satisfactory. Firstly, the chisel must be hand-held and this does not lend itself to accurate guidance of the chisel. Secondly, the act of chiselling the wall may cause plaster work externally of the outline of the recess to chip and flake. It will be readily apparent that if the damaged plaster work is still visible after the front plate of the electrical socket has been fitted, this is not aesthetically pleasing.

A further known technique used to prepare recesses for receiving electrical sockets necessitates the use of a template. This template has a size of the size of the recess which is to be formed and is in the form of a thin plastics material or cardboard sheet. The periphery of the sheet is provided with a plurality of semi-circular cut-out portions which adjoin one another. Such a template is affixed to a wall using, for example, adhesive tape. When affixed to the wall, the cut-out portions indicate drilling points.

By providing a drill hole in the wall in the location of each of these portions, the wall is, effectively, perforated.

The template is then removed and a hammer and chisel are employed to interconnect the drill holes and to form the recess.

In theory, the use of such a template does reduce the time needed to produce the recess in the wall and also facilitates the production of a recess of the desired size.

However, such an arrangement also suffers from certain disadvantages. Firstly, the use of , particularly, an electric drill sets up strong vibrational forces and these may cause the template to become dislodged from the wall.

This problem could, of course, be overcome by permanently affixing the template to the wall using, for example, glue.

Since the portion of the wall surface to which the template has been affixed is discarded after the recess has been formed, no problems arise in th:s respect. Hover, it i31 be readily apparent that once such a template plate has been permanently affixed to the wall, it cannot be reused. A further problem may arise due to the nature of the wall in which the recess is being made. Many houses have cavity walls. Although it is relatively easy to keep a drill steady when drilling through plaster, it is almost invariably necessary to drill into the brickwork located beneath the plaster. Naturally, when the drill strikes the brickwork, there is a tendency for the drill to slip. The guidance offered to the drill by a template is not sufficient to prevent such slippage.

The present invention therefore seeks to provide a jig which can be retained in position on wall or the like and, when located in position, provides guidance for a drill so as to permit the outline of a recess to be drilled accurately in the wall. Furthermore, the present invention seeks to provide a jig which offers sufficient guidance to the drill to prevent, or at least minimise, slippage of the drill when the nature of the wall or the like being drilled changes.

According to the present invention there is provided a jig comprising a base plate having two major surfaces, one major surface being flat and intended, in use, to lie flat against a wall or the like, the second major surface having a plurality of hollow cylindrical tubular members extending substantially perpendicularly thereto, the tubular members being disposed adjacent to one another and corresponding to the outline of the recess to be produced.

As mentioned hereinbefore, the primary intended use of the jig assembly of the present invention is to enable a recess to be formed accurately in a wall to facilitate. 'the fitting of an electrical socket. Accordingly, the free ends of the guide tubes, in a preferred embodiment, define a substantially rectangular outline corresponding to that of an electrical socket.

However, conventional domestic electrical sockets may be single sockets or double sockets. In an advantageous embodiment of the present invention, therefore, the same jig can be utilised for producing recesses suitable for either a single socket or a double socket. It should, however, be borne in mind the recess required to accommodate a double socket is not twice the size of the recess required to accommodate a single socket.Accordingly, in a desirable embodiment of the present invention, a peripheral array of guide tubes is provided, the free ends of the peripheral array of guide tubes defining a rectangular outline corresponding to that of a double socket, a further row of;guide tubes also being provided, which further row of guide tubes sub-divides the rectangle defined by the free ends of the peripheral guide tubes into two smaller rectangles, one of which is larger than the other, the larger of the two rectangles corresponding to the size of a single electrical socket.

As has been mentioned hereinbefore, the nature of the wall or the like in which the recess is being formed is not consistent. Accordingly, it may sometimes be found that the mere drilling of holes in a pattern corresponding to the outline of the recess to be produced is not sufficient. To overcome this problem, an advantageous embodiment of the present invention provides for the provision of an additional set of guide tubes, the free ends of which extend substantially diagonally across one or both of the rectangles defined by the upper ends of the peripheral array of guide tubes or the peripheral array of guide tubes and the further row of guide tubes.

Reference has been made hereinbefore to the free ends of the peripheral tubes defining a rectangular outline. In a desirable aspect, the present invention provides for the free ends of the guide tubes to define a circular outline.

Such a circular outline may be used for providing a circular cross-sectional recess which permits the mounting of wall lights on a wall.

The invention will bb further described, by way of example, with reference to the accompanying drawing, the single figure of which shows a perspective view of a jig assembly in accordance with the present invention.

In the drawing there is shown a jig assembly in accordance with the present invention which comprises a base plate 1 having two opposed major surfaces 2 and 3. One of these surfaces 2 is planar and, in use, is intended to lie flat against a wall. The plate 1 has throughbores 4 formed therein through which a drill may be inserted to drill a hole in the wall. Once these holes in the walls have been drilled, the holes are plugged and the jig assembly is detachably affixed to the wall by means of screws (not shown) so that the planar surface 2 lies flush with the wall.

From the opposed surface 3 of the base plate 1, a plurality of hollow cylindrical guide tubes project substantially perpendicularly. The guide tubes have a circular internal cross-section so dimensioned as to be capable of receiving a drill. The tubes 5 are located adjacent one another and may be interconnected by any suitable means, such as webs, so as to impart added rigidity to the tubes. The shape defined by the free ends of the tubes 5, which are all of the same length, corresponds to the outline of a recess which it is desired to provide in the wall.

As shown in the drawing, this outline is suitable for forming a recess capable of receiving a double electrical socket.

In the drawing, it will be seen that there is a further row of guide tubes 6 extending substantially parallel to the shorter sides of the rectangle formed by the free ends of the peripheral guide tubes 5. The guide tubes 6 are identical to the guide tubes 5 and may also be interconnected to provide added rigidity. It will be seen that the row of guide tubes 6 divides the rectangle formed by the free ends of the guide tubes 5 into two smaller rectangles, one of which is larger than the other. The larger of these rectangles corresponds substantially in size to that of a single domestic electrical socket.

It will further be seen that each of the two rectangles formed by the inclusion of the row of guide tubes 6 includes an additional diagonal row of guide tubes. These guide tubes 7 are identical in size to the guide tubes 5 and 6. It will be readily apparent that these diagonal rows of guide tubes 7 divide each rectangle in half. The purpose of this will become apparent hereinafter.

The use of the jig assembly in accordance with the present invention will now be described. The jig assembly is held against the wall or the like in which a recess is to be provided in a desired location. The position of the apertures 4 is then marked. The jig assembly is then removed an holes are drilled at the locations which have been marked.

After plugging these holes, the jig is affixed to the wall by means of screws so that the planar surface 2 of the jig lies in abutment with the wall.

At this stage, it will be assumed that it is desired to perform a recess in a wall to accommodate a double electrical domestic socket. Using a suitable masonry drill, holes are drilled in the wall by inserting the drill into each of the guide tubes 5 in turn. By suitably selecting the length of the guide tubes, or by providing a stop member on the drill itself, the depth of penetration of the drill into the wall can be controlled. After drilling a hole in the wall through each of the guide tubes in turn, the jig assembly is removed from the wall by unscrewing the screws holding the jig assembly in position. The wall now has a series of holes formed therein, the holes being in a rectangular array. These holes are relatively close together and, in essence, the wall has been perforated. The undrilled portions between each hole can then be readily removed using a hammer and chisel.

When all of the material has been removed, there remains a recess suitably sized so as to receive the box member of a domestic electrical double socket. By controlling the depth of penetration of the drill into the wall, the recess thus produced will not be excessively deep. Although the formation of an excessively deep recess has no adverse effect upon the installation of the socket, time and effort will have been wasted in removing the surplus material. Moreover, the jig assembly of the present invention ensures that the recess produced is sufficiently large to receive the box member or members of a double socket whilst, at the same time, ensuring that the recess in the wall will be hidden by the front plate of the socket member once this has been affixed.

The same procedure is followed if it is desired to make a recess which is capable of receiving a single domestic electric socket. However, in this case, not all of the peripheral guide tubes 5 are utilised. Instead, the user merely drills through the guide tubes 5 and 6 defining the larger or the two internal rectangles.

If the wall or other material into which drilling is being effected proves particularly resistant to drilling, it may be desirable to drill through the guide tubes 7 in a manner similar to that described hereinbefore with reference to the guide tubes 5 and 6. By so doing, once the jig has been removed from the wall, the user merely has to chisel out two relatively small triangular sections as opposed to a relatively large rectangular portion.

It will be readily apparent that various minor modification can be made to the jig assembly of the present invention without departing from the scope thereof. Thus, for example, the guide tubes may be disposed in a circular array. This is of use when forming a recess in a wall into which a wall light is to be mounted. It would also be possible to provide a solid central base plate having guide tubes formed thereon and a plurality of annular ring plates, also carrying guide tubes, which can be attached to the solid circular base plate. By so doing, the diameter of the jig assembly can be varied and a single jig may be used for forming recesses of different diameters in the wall.

Claims (6)

1. A jig comprising a base plate having two major surfaces, one major surface being flat and intended, in use, to be flat against a wall or the like, the second major surface having a plurality of hollow cylindrical tubular members extending substantially perpendicularly thereto, the tubular members being disposed adjacent to one another and corresponding to the outline of a recess to be produced.

2. A jig as claimed in claim 1, wherein a peripheral array of guide tubes is provided, the free ends of the guide tubes define a substantially rectangular outline corresponding to the shape of an electrical socket.

3. A jig as claimed in claim 2, wherein a peripheral array of guide tubes is provided, the free ends of the peripheral array of guide tubes defining a rectangular outline corresponding to that of a double electrical socket, a further row of guide tubes also being provided, which further row of guide tubes sub-divides the rectangle defined by the free ends of the peripheral guide tubes into two smaller rectangles, one of which is larger than the other, the larger of the two rectangles corresponding to the size of a single electrical socket.

4. A jig as claimed in claim 2 or 3, wherein at least one additional set of guide tubes is provided, the free ends of the additional set of guide tubes extending diagonally across one or both rectangles defined by the upper ends of the peripheral array of guide tubes or by the peripheral array of guide tubes and the further row of guide tubes.

5. A jig as claimed in claim 1, wherein the free ends of the guide tubes define a circular outline.

6. A jig as claimed in claim 1 constructed and arranged to operate substantially as hereinbefore described with reference to the accompanying drawings.