GB2479146A

GB2479146A - Hole cutter

Info

Publication number: GB2479146A
Application number: GB1005327A
Authority: GB
Inventors: Paul James Bentley
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-03-30
Filing date: 2010-03-30
Publication date: 2011-10-05
Also published as: GB201005327D0

Abstract

The circular cutter 1 may be used to produce a round hole in masonry, breeze block, brick etc to excavate a majority of the hole prior to a square cutter being used. The cutter includes a body member of dimensions approximating to the hole size required. The body member includes a base with a plurality of cutting faces. Wings 3 are provided with one or more teeth inserts 4, projections of a hard material such as tungsten carbide, and a plurality of debris egress apertures 5. A drive connection (6, Figure 2) projects from the opposite side of the inserts and is profiled for fitting in the chuck of a standard hammer drill. The base may be apertured at its centre to receive a drive spindle. The cutter may be provided with a pilot nose or guide rod projecting beyond cutting edges.

Description

Title of invention

TRJ CUT EBS

Field of the invention

This invention relates to a circular cutter to precede the use of a square hole cutter in the production of rectangular, and particularly square holes apertures or recesses (hereinafter referred to as a hole) in masonry, concrete, breeze block, bricks plaster etc. Typically excavating a round hole so the majority of the hole is excavated before a square cutter is used to complete a square hole recess to receive an industry standard metallic or plastic socket box to receive e.g. an electric switch or socket or likewise.

Background of the invention

The current circular cutter supplied with the square cutter performs the pre-excavation of the square hole adequately in for example breeze block but is not as good on hard brick. With this in mind the idea for a new improved round cutter was set about which could not only be more efficient in hard brick but also reduced the vibration allowing an electrician or fitter to drill more holes before maximum vibration exposure is reached.

Object of the invention The object of the invention is to produce a better version of the current round cutter to be more efficient in harder materials and also reduce vibration for the operator resulting in more holes being drilled before the legal maximum vibration exposure is met.

Summary of the invention

A round/circular cutter for use in producing a round hole in masonry etc to excavate a hole preceding a square cutter, with a body approximating the dimensions of the hole required, comprising a plurality of cutting faces, arms, wings each with inserts of hard material i.e. tungsten carbide with a drive connection on the opposite side of said inserts and so profiled for an adaptor to fit in an industry standard chuck.

Advantages of the Invention With the cutter in accordance with the invention the circular hole that precedes a square hole may be produced with a hammer drill with less vibration so more holes can be drilled before the maximum vibration exposure is met. And also the cutter will be quicker in harder materials than the previous round cutter and a longer life achieved due to more tips and a quicker drilling speed. n

Preferred Optional Features The tips of the cutter should be made of tungsten carbide or similar.

The body itself should be formed by method of cast.

The opposite side of the cutting face should be machined to receive an adaptor to fit an industry standard chuck.

The cutter should be supplied with an adaptor to fit an industry standard chuck.

Brief Description of Drawings

In the accompanying drawings: Figure 1 is an elevation on the rear end of the body member of Fig 4 in accordance with the invention.

Figure 2 & 3 is an explode view of Fig 7 in accordance with the invention.

Figure 4, 5 & 6 are a front elevation and two side elevations in accordance with the invention.

Fig 7 is an isometric view of the cutter and the adaptor in accordance with the invention.

Detailed Description of Drawings

A cutter (I) for use in producing a circular hole in masonry, breeze, brick ete, to excavate the majority of a hole preceding a square cutter comprising a body member (2) of dimensions approximating to the hole size required the body member (2) comprising a base with a plurality of cutting faces, arms, wings (3) provided with one or more inserts, (4) teeth, projections of hard material such as tungsten carbide or similar material, which provide a plurality of debris aggress apertures (5) and with a drive connection (6) projecting from the opposite side of said inserts and so profiled for fitting an industry standard chuck.

The cutter (1) has a rearward projecting spigot (7) provided with a female threaded hole (8) to receive a male threaded adaptor (9). The body member (2) is apertured at its centre to receive the drive spindle adaptor (9) providing a pilot guide rod (10) to project beyond the inserts and cutting edge. The adaptor will be provided with a shank (1 1) so suited to fit an industry standard hammer drill.

Claims

Claims I) A circular hole cutter for use in producing a round hole in masonry, breeze, brick Etc, to excavate the majority of a hole preceding a square cutter, comprising a body member of dimensions approximating to the hole size required, the body member comprising a base with a plurality of cutting surfaces, an arm, wings provided with one or more inserts, teeth, projections of hard material such as tungsten carbide or similar material, which provide a plurality of debris egress apertures and with a drive connection projecting from the opposite side of said inserts and so profiled for fitting in the chuck of an industry standard hammer drill.
2) A cutter as claimed in claim (1), wherein the base is apertured at its centre to receive a drive spindle.
3) A cutter as claimed in claim (2) wherein the cutter is provided with a pilot nose/guide rod projecting beyond the cutting edges.
4) A cutter as claimed in any preceding claim, wherein at least some components are produced by way of cast.
5) A cutter as claimed in any preceding claim wherein the body member is made of steel.
6) A kit of parts comprising, in combination a cutter in accordance with any of the preceding claims, and a drilling tool having a shank adapted for fitting an industry standard hammer drill.
7) A kit of parts as claimed in claim (6) wherein the drilling tool is a rotary drilling tool.
8) A kit of parts claimed in claim (6) where the cutting tool is provided with a pilot drill for use in an industry standard chuck.