AU665336B2

AU665336B2 - Optimising chasing chisel

Info

Publication number: AU665336B2
Application number: AU79367/91A
Authority: AU
Inventors: Ron Kempin
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-08-02
Filing date: 1991-06-26
Publication date: 1996-01-04
Anticipated expiration: 2011-06-26
Also published as: AU7936791A

Description

1

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Page I This invention relates to an optimising chasing chisel with improvements in cutting grooves, chases and penetrations in brickwork and masonry. The invention also provides improvements in laminar separation of brickwork and masonry for the removal of ceramic tiles and/or rendering. This chisel is especially designed for cutting grooves, recesses and penetrations into brick structures. No dust is produced. The chisel provides for optimisation of the removal of materials by laminar separation.

Accordingly, the invention is directed to an optimising chasing chisel for cutting grooves, recesses, and penetrations comprising in elevation view, a handle merging into (ii) a tapered tool end with a curved upper concave surface (iii) a flat lower surface angled to the extended longitudinal axis of the handle (iv) a bevel between the curved upper surface and the flat lower surface to form a lending edge in plan view, the leading edge is V-shaped, ranging in width from 15mm to optional size (ii) a U-shaped recess with an optional radius is located at the junction ofthe V, optional in depth in relation to the foremost leading edge (iii) a handle as above, merging into the tool end by means of a radial curve.

As indicated above, the chisel is made in one piece from heat treated, shock resistant cold I 3 work tool steel. For example, water quenched and tempered carbon-vanadium cold work I 30 tool steel or similar may be used.

Z FIGURE 1 in plan view and FIGURE 2 in end elevation illustrates twin, opposing, angled beveled blades 6. FIGURE 3 in elevation clearly illustrates the bevel on the blade 6 and the flat surface 4 angled to the extended axis of the handle.

a. o PRIOR ART: CHASING BRICKWORK AND MASONRY.

At present, groove cutting, or clasing for the concealment of plumbing pipes and electrical conduit and cables, is effected by three stage process as follows: Stage 1 and 2: Two cuts are made in the brickwork or masonry with a friction saw. This operation generates large t o 40 volumes of dangerous silica dust, which is very harmful to health. Stage 3: The material between the two cuts is then removed by hand or machine driven cold chisel hammer.

NEW ART: CHASING BRICKWORK AND MASONRY.

The optimising chisel 10 will generate a groove in one operation. The twin opposed and angled blades 6 impose shock waves, crossing each other in front of the chisel 10, causing an IMPLOSION in that confined area (see FIGURE generating a clean groove, without shattering or defacing the surrounding area. The operation requires no sawing and generates no dust. The new chisel is designed Tor use by hand/electric/air operated hammers.

Snumber.

~L"nr^rr-l; 1 i Page 2 PRIOR ART: BRICKWORK AND MASONRY PENETRATIONS.

The standard cold chisel 20, having a double beveled cutting edge 11, (see FIGURE is used basically as a wedge for EXPLODING the piece of brickwork or masonry off the surface, in wide radius around the point of impact (see FIGURE The standard cold chisel is an EXPLOSION chisel and needs to be driven at an angle of 60 to 90 degrees to the surface to be cut, (see FIGURE until that section of the brickwork or masonry explodes off in a wide and random radius around the point of impact, (see FIGURE The method is slow and can damage the structure of the brickwork or masonry.

NEW ART: BRICKWORK AND MASONRY PENETRATIONS.

The optimising chisel 10, by generating an IMPLOSION between the twin blades 6, (see FIGURE will cut a clean profile in brickwork and masonry, without damaging the surrounding area or structure. It can be operate at any angle in relation to the surface from to 90 degrees, (see FIGURE The operation of the implosion principle is fast, dust free and safe and causes no damage to the structure of the brickwork or masonry.

PRIOR ART: LAMINAR SEPARATION FOR REMOVAL OF CERAMIC TILES AND/OR RENDER.

The standard hand or machine driven cold chisel 20, having a double bevel single blade 11, (see FIGURE needs to be driven at an angle between 60 and 90 degrees in relation to the surface to be cut, (see FIGURE If the angle is reduced below 60 degrees the chisel will glance off. At an angle of attack of 60 degrees, the cold chisel will generate an explosion in a radius around the point of impact, (see FIGURE removing a piece of the tile and substructure, leaving the surface rough, requiring rectification work to provide a smooth surface.

i: NEW ART: LAMINAR SEPARATION FOR REMOVAL OF CERAMIC TILES AND/OR

RENDER.

*i The optimising chisel 10 has a single bevel 5 similar to a wood chisel, (see FIGURE 3).

This single bevel 5, combined with twin angled blades 6(see FIGURE allows the optimising chisel to be used at angles as low as 5 degrees to the surface being cut, S (see FIGURE When the optimising chisel is driven under the edge of the tile, the tips 8 of the twin cutting blades engage on the first impact, holding the chisel down firmly to the surface. On the second impact, an IMPLOSION is generated in the mortar bed below the tile, ejecting the tile cleanly from the surface of the mortar or masonry, (see FIGURE 6).

This mode of operation provides a very fast, clean and safe laminar separation, leaving the surface of the substructure smooth and regular, requiring no rectification work for further processing.

Application number.

79367/91.

Claims

1. An optimising chasing chisel (10) for cutting grooves, recesses and penetrations comprising in elevation, a handle merging into (ii) a tapered tool end with a curved upper concave surface (iii) a flat lower surface angled to the extended longitudinal axis of the handle (iv) a bevel between the curved upper surface and the flat lower surface to is form a leading edge in plan view, the leading edge is V-shaped, ranging in width from 15mm to optional size. (ii) a U-shaped recess with an optional radius is located at the junction of the V, optional in depth in relation to the foremost leading edge (iii) a handle as above, merging into the tool end by means of a radial curve

2. An optimising chasing chisel according to claim 1, wherein the material for the chisel is heat treated, shock resistant cold work steel.

3. An optimising chisel according to Claim 2, wherein the steel is water quenched and tempered carbon-vanadium cold work tool steel. S 30

4. An optimising chasing chisel according to Claim 1, 2 or 3, which has application to chasing of brickwork and masonry penetrating brickwork and masonry, f as laminar separation for the removal of ceramic tiles and/or render.

5. An optimising chasing chisel, according to Claim 1, substantially as hereinbefore described, with reference to the accompanying drawings. 4 4* 4* 4

79367191.