GB2050212A

GB2050212A - Masonry drilling guide

Info

Publication number: GB2050212A
Application number: GB7919775A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-06-07
Filing date: 1979-06-07
Publication date: 1981-01-07

Abstract

A masonry drilling aid comprises a sleeve 4 with a flange 3 having slots 8 forming a cross. The slots are aligned with a marked cross to centralise the sleeve 4. A drill guide 5 or expendable ferrule is slidable in the sleeve 4. The guide end is sharp to penetrate plaster and to be retained by the plaster when a drill bit is applied to the plaster. <IMAGE>

Description

SPECIFICATION Masonry drilling aid This invention relates to apparatus for use with conventional rotory masonry drills in a manner which assists in the accurate location of the drilled hole and a particular, but not sole, application of the invention is to the drilling of holes in plastered walls as may be found in a typical dwelling house. Because of its relatively soft texture, plaster does not always provide the required support to the drill as it enters the wall and there is a tendency for the drill to go off centre as it seeks an easy entry into the backing brickwork.

This tendency is particularly undesirable when the article to be fixed to the wall has more than one fixing hole at fixed locations.

This invention seeks to provide means of ensuring more robust support for the drill during its initial entry into the wall in a manner whereby a relatively unskilled person may drill holes in walls with reasonable accuracy.

According to the present invention a masonry drilling aid comprises a first part suitably adapted to serve as a marking template whereby a suitable mark including a cross may be placed on the wall to indicate the centre of the intended hole and the said cross being subsequently viewed the sighting slots in a second part in which position a central hole in the said second part is coaxial with the centre of the wall marking said central hole serving as a guide to a third part which is adapted to serve in the first instance as a punch whereby a sharp blow at the end of the third part furthermost from the face of the wall causes a sharpened extremity at the other end of the third part to become embedded in the plaster and thus hold the assembly of the second and third parts firmly to the face of the wall at the required location in which position a central hole in the third part serves as a guide to the drill in drilling the hole in the wall.

According to a second embodiment of the invention a masonry drilling aid for use by persons more skilled in drilling in a perpendicular manner is arranged in a modified form to embrace the essential principle described for the first embodiment above wherein the said first part is used in the described manner for marking the wall but the said second part while retaining the said sighting slots is made in a shortened form and is used solely as a guide for the driving of a suitably shaped and sharpened ferrule into the plaster said ferrule remaining permanently embedded in the plaster and providing means whereby the hole in the wall may be drilled via the central hole in the said ferrule.

In order that the invention may be more readily understood it will be explained, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a plan view of the first part.

Figure 2 is a plan view of the assembly of the second and third parts.

Figure 3 is a part sectional elevation of the assembly of the second and third parts.

Figure 4 is a cross section of the ferrule in accordance with a second embodiment of the invention.

Figure 5 is a plan view of the modified second part in accordance with a second embodiment of the invention.

Figure 6 is a part sectional elevation of the modified second part in accordance with a second embodiment of the invention.

Figure 7 is a cross sectional view of the apparatus in use in accordance with the first embodiment of the invention.

Figure 8 is a cross sectional view of the apparatus in use in accordance with the second embodiment of the invention.

Referring to Fig. 1 a marking template 1, preferably made from a suitably strong thin transparent plastic sheet is provided with slots 2 which in a preferred arrangement are in the form of a cross. In use the marking template 1 is held flat against the wall at a position where the centre of the cross is coincidental with the centre of the hole to be drilled into the wall and while in this position a cross is marked on the wall with a suitable instrument.

Figs. 2 and 3 show the assembly of the second and third parts of the invention in which a centrally located body 4 shown in typical circular outline serves as a guide to a drill guide bush 5 which has a sliding relationship with central body 4. The central body 4 is provided at one end with a flange 3 which may have any suitable outline. A plurality of slots 8 are provided in the flange 3 in order that the lines drawn on the wall by use of the marking template 1 may be sighted and the apparatus centralised accordingly. The innermost end of the drill guide bush 5 is arranged with a tapered counterbore 7 the leading edge of which is sharpened and suitably hardened.

The outermost end of the drill guide bush 5 is upset in a manner that limits its movement toward the wall. With the apparatus lined up with the wall markings the outermost end of the drill guide bush 5 is given sufficient sharp blows to cause its innermost sharpened end 7 to penetrate the plaster surface of the wall.

In this position and with the flange 3 held flat against the wall the drilling of the hole may be executed as generally shown in Fig. 7 with the drill being guided by the central hole 6 in the guide bush 5.

In a second embodiment of the invention the masonry drilling aid appears in a modified form but using the same principles as described for the first embodiment.

Figs. 4, 5 and 6 show that the drill guide bush 5 (Figs. 2 and 3) has been replaced with a ferrule 9 the end 10 of which is prepared in the same manner as described for the end 7 of the bush 5 (Figs. 2 and 3). Whereas the end of the drill guide bush is retractable and can be used many times the ferrule 9 is expendable and can if so desired remain permanently embedded in the plaster. The hole in the wall is then drilled using the central hole 11 in the ferrule 9 as a guide.

In order to ensure that the ferrule is embedded in the plaster at the required location a guide device 1 2 of similar form to that described for the first embodiment is provided with sighting slots 14 to enable the apparatus to be correctly alligned with the wall marking said guide being provided with a central hole 1 3 of essentially the same diameter as that of the ferrule 9.

Fig. 8 shows this modified form of the apparatus in use. The guide 1 2 is held firmly against the wall having be alligned with the wall markings and the ferrule 9 is held on the spigot of a suitable punch 1 5 ready for embedding in the plaster via the central hole 1 3 in the guide 12.

Claims

1. A drilling aid comprising a base part adapted to lie against the wall at a location where a hole is to be formed, a hole in the base part and means on the part to align the hole in the part with an indication on the wall at the required location of the hole, a further part in the form of a hollow punch having an end adapted to be driven into the wall through the hole in the first part to provide a guide for a drill.

2. A drilling aid as claimed in Claim 1 wherein the base part is formed with a hollow tubular guide concentric with the hole to guide the further part through the hole.

3. A drilling aid as claimed in Claim 2 wherein the hollow tubular guide has a counterbore at the end remote from the bore part to provide a shoulder facing forward at the open end of the guide and the hollow punch has an encircling shoulder adjacent the end remote from said end adapted to be driven into the wall, the shoulder in the tubular guide when the end of the punch projects from the base part to be driven into the wall.

4. A drilling aid as claimed in Claim 1 or Claim 2 wherein the hollow punch is in the form of a ferrule to be embedded into the wall by other means such as a hand held punch.

5. A drilling aid as claimed in any of the preceeding claims wherein the base part is formed with cross slots aligned with the access of the hole in the base to enable the base to be aligned with a cross marked on the wall.

6. A drilling aid as claimed in any of the preceeding claims wherein a template is provided having intersecting cross slots for marking a cross on a wall at a location where a hole is to be formed.

7. A drilling aid to assist in the drilling of masonry as hereinbefore described with respect to the accompanying drawings.