AU771795B2

AU771795B2 - Improvements to cutting tools a nibbler, jigsaw and knife attachment to an electric drill

Info

Publication number: AU771795B2
Application number: AU31297/00A
Authority: AU
Inventors: Alan Mitchell
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-05-05
Filing date: 2000-05-04
Publication date: 2004-04-01
Anticipated expiration: 2020-05-04
Also published as: AU3129700A

Description

A nibbler, jigsaw and knife attachment to a drill.

This invention relates to a novel nibbler, jigsaw and knife cutting tool which can be attached to an electric drill The tool is essentially a nibbler which cuts on the upstroke. A novel part of the nibbler is that the tool can be used to cut at two places on the barrel.

(s3) When cutting flat sheet material or corrugated iron, the metal is passed between the the forepart at the first slot in the barrel. When an aperture is required to be cut, the tool can be used to cut on the forepart of the barrel. When cutting a small aperture, a narrow end of the blade is used. This end is narrower in depth and more sharply tapered. This allows the tool to negotiate a small radius. The forepart of the barrel and its slot are so shaped to allow the tool to cut corrugated iron or even a right angle cut on a gutter.

The tool is also a jig saw and a knife. To prevent interference with the cutting anvil, the teeth of the jig saw and the edge of the knife blade are set below the upper surface of the blades. All blades have a central saddle portion which straddles the rim of an angled ball race. This ball race fits a rotating body coupled to a nut fitted to the drill spindle after the chuck has been removed.. Blades fit a slotted barrel, the depth of the slot being slightly deeper than the depth of the blade to give working clearance.

Other versions of the same invention will also be described with relation to drawings,"A","B" and A body part ideally moulded in a suitable plastic, is recessed at to fit the parallel part of a drill body which is behind the drill chuck. On an electric drill this is 43 m.m. in diameter. A clamping screw allows clamping to the drill body. Several slots allow some flexing, allowing the body to fit drills which vary slightly in the 43 m.m. part. At the extreme right of the drawing is shown a .e9tion of a drill body labeled to which the plastic body fits.

(2 5 Ti§~ dy part of plastic or metal is fitted with a bearing which can be one or more ball races or a hardened bush. The latter is shown at To this bearing is fitted a spindle assembly comprising of three parts. At the right side of the spindle is fitted a driving socket shown fitted with a flange and threaded into the spindle.

Distal to that on the left of the spindle is fitted an angled ball race holding block .o This is machined to accept an angled ball race (13) which is retained by circlip The balt race mounting block is shown internally threaded to take a drill chuck the threaded portion (16) fittingthe block (12).

The revolving angled ball race, gives the required reciprocation to the cutting blade.

To the upper portion of the body part is fitted a hardened steel bush This .iii3 bush accepts the barrel (22) and is slotted vertically at (34) to take a peg in the barrel. The bush is machined eccentric to give more material on the upper side in order to give sufficient metal for a thread to take the barrel holding screw (19) which is fitted with a lock nut (20) to prevent slackening of the screw during use of the tool. The locking screw is pointed at the point entering a countersink hole in the barrel.

The Barrel.

The barrel is made ofteughened steel and is round bodied up to the forepart which contains the cutting anvils. The barrel (22) is slotted from the bottom side to be slightly deeper than the depth of the cutting blades. The enlarged zS2 forepart is slotted at (23) and It is from these slots that the cutting chips emerge when cutting. The foremost slot (23) is also slotted vertically on both sides fss) a.i shaped to be curved in order to allow the tool to cut corrugated iron. A web of metal, (27) thinner than the cutter blade is left. This web has to be thinner than the blade in order to pass through the cut being made by the blade.

The cutting anvils, (25) and (26) are fitted, They can be of hardened steel or Tungsten carbide and silver soldered in place.

Blades.

Blades are shown in drawing The blade (30) is shown with a central saddle portion Th left side of the blade is shown fitted with two cutting notches. The f6remost notch is used to cut when the forepart of the barrel is resting on the material. The cutting chips then emerge from the first slot (23) in the barrel.

The second notch (34)4in tle cutter will make the cut when the material is fed between the first slot the cuttings emerging from the second slot (24) The right hand side of the cutting blade is shown narrowed and is more sharply tapered. This end is used to cut apertures as a small radius will result. A hole as small as 20m.m. diameter can be cut with this blade.

Cutting corrugated iron, The tool is fitted with the wide end of the blade for cutting and the tool will follow the curves of the iron with the chips emerging from the 6) secqnd slot. An aperture is cut using the narrow end of the blade which is inserted in a slot cut in the material, Cutting is done at the forepart of the barrel and the cuttings emerge from the first slot. To cut on the forepart of the barrel, the material is rested upon a sheet of polystyrene foam. This supports the sheet and the blade can penetrate the foam.

The cutting notch in the blade is not v4 'A deep notch will cut fast but leave a ragged edge.

A drawing of the plastic body is repeated on drawing It shows the plastic body fitted with the steel bush (18) which supports the barrel (shown shaded) The tool is also a jigsaw and a knife. A jigsaw, knife blade, shown double ended, is shown at (35) The teeth of these blades are set below the top surface of the blade so as not to interfere with the cutting anvils on the barrel.

A safety cover is shown at This is this open on the front at (37) to allow a drill chuck to be fitted without removing the cover. An angled sl6t allows the cover to fit two pegs on the plastic body. (not shown) Rotating the cover locks the cover onto the body.

A round cutter tool. (drawing Instead of a flat blade the tool can be fitted with a round blade which also cuts on the upstroke. Such a tool is shown, the barrel (39) is bored at to take a round bodied shuttle (41) fitted with a saddle (42) and a round bodied punch (43) which is threaded to fit the shutile body A 16lit nut (44) is shown.

The blade is there fore adjustable longitudinally. The blade sas a cutting notch or slot (45) at its forepart. This notch is cut to be ecchtric to tie body. This gives it more strength as it is not meant for use on heavy materials.

The forepart of the barrel is similar to the flat bpi l c-er barrel and the cutting g(9) slots are labeled the same numbers, (23) and (24) The tool cuts in the same manner as the flat blad4ed utte. It has one advantage in that the tool can be rotated upon the round blade tqcuta squared corner with a m.m. radius corner. This is an advantage for cutting electronic panels.

A shearing tool.

This tool is shown also in drawing It cuts on the down stroke and only requires a barrel with one slot as shown in (47) The blade, (51) has curved cutting edges and cuts as this part enters the anvil. It is fast cutting and suitable for thin gauge material such as aluminium or plastic.

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