AU755733B2

AU755733B2 - Tool for loosening fastening devices

Info

Publication number: AU755733B2
Application number: AU65242/99A
Authority: AU
Inventors: Bernard Paul Van De Wetering
Original assignee: COSSACK TOWNS Pty Ltd
Current assignee: COSSACK TOWNS PTY Ltd
Priority date: 1998-12-16
Filing date: 1999-12-16
Publication date: 2002-12-19
Anticipated expiration: 2019-12-16
Also published as: AU6524299A

Description

Regulation 3.2 -1-

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION 4 4* 4* 4* t. *r STANDARD PATENT APPLICANT: COSSACK TOWNS PTY. LIMITED

NUMBER:

FILING DATE: Invention Title: TOOL FOR LOOSENING FASTENING DEVICES The following statement is a full description of this invention, including the best method of performing it known to me: 2 TOOL FOR LOOSENING FASTENING DEVICES Technical area This invention relates to the area of tools for the loosening and removal of fastening devices which devices include screws, bolts, nuts and the like.

Background to the invention It is often difficult to remove screws, bolts, threaded studs, common nuts, left and right hand threaded fasteners and other such devices. Many fastening devices are designed not to be undone and include one way screws and tamper proof screws and bolts.

Other fasteners may be difficult to remove because of damage such as damaged heads for bolts and screws and in fact heads of like devices may have been broken off. Extracting these devices can be time consuming and complicated particularly where they are difficult to access. Past removal techniques usually require that a damaged head of a screw or bolt be sawn off and the remainder of the device be either drilled out or have a centre hole drilled WP51\SPEC\WETERING-CAP\BV\15 December, 1999 3 therein to receive a stud remover. This procedure is particularly difficult where access is an issue.

Outline of the Invention It is the object of this invention to provide a tool for removing broken, deformed, damaged and anti removal type bolts, screws studs and nuts of either right or left hand thread.

The invention is a tool device including a body having a first end integral with a first member adapted to engage with a driving tool, and a second end integral with a second member having a cutting face which is provided with at least one tooth device on the periphery thereof such that, when the tooth device contacts a fastener to be removed and a force is applied to the driving tool, the tooth device at least partially enters the fastener and the tool device is caused to rotate causing an equivalent ooooo S rotation of the fastener and thereby loosening the fastener.

Once the fastener has been loosened the whole assembly can be rotated in a screw driver action to remove the fastener.

It is preferred that the driving tool be an impact driver although other appropriate devices may be used. It may also be wp51\SPEC\WETERING-CAP\BV\15 December, 1999 4 preferred that the second member be substantially cylindrical in shape although the invention is not limited to this shape.

It is further preferred that there be a plurality of tooth devices provided in order to provide good grip into a fastener.

It is also preferred that the tooth device used extend upwards and laterally from its base from the centre of the body of the tool device and have its maximum height at the periphery of that body. It is further preferred that an upper edge of the tooth o device be chamfered to reduce the possibility of a sharp edge of the tooth breaking.

It is preferred that where the tool device is to be used to undo a nut or bolt that the diameter of the second member be of a similar diameter to that of the object being unfastened. It is also preferred that where the device is to be used to remove a fastener which is recessed within another body that the second member of the tool device have a slightly smaller diameter than that of the recess.

In order that the invention may be more readily understood we shall describe by way of non limiting example specific embodiments thereof with reference to the accompanying drawings.

WP51\SPEC\WETERING-CAP\BV\15 December, 1999 Brief Description of the Drawing Figures Fig. 1 Shows a diagrammatic representation of an embodiment of the invention for use on nuts or bolt heads and the like; Fig. 2 Shows a plan view of the cutting face of the invention; Fig. 3 Shows a side view of a first embodiment of the invention; Fig. 4 Shows a side view of a second embodiment of the invention for use inside an aperture.

In a first embodiment 10 of the invention (Figure 1) the tool device is manufactured from tool metal and has a cylindrical body 20 connected at one end 21 to a hexagonal head 22 designed to engage with an impact wrench or other such device.

The other end 23 of the body is connected to a tubular member 24 terminating with four tooth members 25 arranged equally to form the cutting face of the tool.

The teeth 25 have their maximum height at the periphery of the tubular member 24 and have a sharp cutting edge 26 slanting WP51\SPEC\WETERING-CAP\BV\15 December, 1999 6 downwards and inwards towards the centre of the cutting face.

The arrangement is such that when the cutting face is placed over the head of a nut or bolt or other such fastener and a force is applied to the impact wrench the teeth dig into the fastener and a rotatory motion is applied which consequently causes the fastener to rotate thereby loosening the fastener and enabling it to be unscrewed.

The tooth shape is not critical to the invention however in this embodiment of the invention a bevel 27 is provided at the tip of each tooth and part way down each cutting edge 26 to minimise the possibility of the metal fracturing.

In another embodiment 30 of the invention (Figure 2) the cylindrical member 31 with the cutting face of the tool is of a diameter which enables it to enter into another aperture in which a fastening device may be located. This tool is then operated as previously described.

In a further embodiment of the invention it is envisaged that a locating spike may be positioned in the middle of the cutting face to act as a guide.

WP51\SPEC\WETERING-CAP\BV\15 December, 1999 Whilst we have described several specific embodiments of the invention it is envisaged that other embodiments of the invention will exhibit any number of and any combination of the features previously described.

It is therefore to be understood that variations and modifications in this can be made without departing from the spirit and scope of the invention.

*i WP51\SPEC\WETERING-CAP\BV\15 December, 1999

Claims

1. A tool device including a body having a first end integral with a first member adapted to engage with a driving tool, and a second end integral with a second member having a cutting face which is provided with at least one tooth device on the periphery thereof such that, when the tooth device contacts a fastener to be removed and a force is applied to the driving tool, the tooth device at least S. partially enters the fastener and the tool device is caused to rotate causing an equivalent rotation of the fastener and thereby loosening the fastener.

2. A tool device as claimed in claim 1 in which the driving go tool is an impact driver.

3. A tool device as claimed in claim 1 having a plurality of tooth devices.

4. A tool device as claimed in claim 3 wherein each tooth device has a base near the centre of the cutting face of the second member and extends upwards and laterally WP51\SPEC\WETERING-CAP\BV\15 December, 1999 therefrom to a maximum height at the periphery of the second member.

A tool device as claimed in any one of claims 1 to 4 in which an upper edge of the tooth device is provided with a bevel.

6. A tool device as claimed in any one of claims 1 to .f wherein the cutting face has a diameter of the same order of magnitude as that of a nut or bolt to be removed.

7. A tool device as claimed in any one of claims 1 to wherein the diameter of the second member and cutting face is less than that of an aperture having a fastener to be •removed recessed therein. t*

8. A tool device as claimed in claim 1 wherein the cutting face has a centrally located guide pin.

9. A tool device as claimed in any one of claims 1 to 8 in which the second member is substantially cylindrical Wp51\SPEC\WETERING-CAP\BV\15 December, 1999 I I A tool device substantially as herein described with reference to the accompanying drawings. DATED THIS 16 th DAY OF DECEMBER 1999 Cossack Towns Pty. Limited By its Patent Attorneys A. TATLOCK ASSOCIATES 0* 0:6 00.0 WP51\SPEC\WEERING-CAXP\SV\15 December, 1999