AU599513B2 - An element for removal of sheared fixing means - Google Patents

Description

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COMMONWEALTH OF AUSTRAL& 99,51 3 Patents Act 1952 COMPLETE SPECIFICATION (Ori4ginal) FOR OFFICE USE Application Number:P16790 Lodged: i5/2/88 Complete Specification Lodged: Accepted: Published: Priority: Class Int. Class ,ttt# t ,r t~ r t r C t*

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Related Art: TO BE COMPLETED BY APPLICANT Name of Applicant: Bertram Hewitt Address of Applicant: 82 Coogee Road Wanneroo in the State of Western Australia, Commonwealth of Australia Actual Inventor: Bertram Hewitt Address for Service:- Wray Associates Primary industry House 239 Adelaide Terrace Perth Western Austral.ia 6000.

pOO)553 07/09/88 Complete Specification for the invention entitled: "An Element for Removal of Sheared Fixing Means" The following statement is a full description! of this invention, including the best method of performing it known to me:- 2 THIS INVENTION relates to an extraction facilitate removal of sheared fastening invention has been devised particularly, but to facilitate extraction of sheared studs.

device to members. The not solely, Where fastening elements such as machine screws, bolts and studs are employed to fasten objects together, the heads of such fastening elements can sometimes shear from the shanks of the fastening elements as a result of the application of excessive torque to the fastening elements or weakness in the fastenirtg elements. In such a situation it is sometimes extremely difficult to remove the shank of 4: a sheared fastening element from the body in which it is embedded without extensive damage to the body.

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4., 44 4' 4-34, *1 4 The present invention seeks to provide a novel device which can be readily fixed to the shank of a sheared fastening element to facilitate removal thereof.

TZ one form the invention resides in an extraction device for facilitating removal of a sheared fastening element comprising a body having a first face, a second face opposite to said first face and a passageway extending between the said faces, said body being provided with at least one portion extending inwardly at or adjacent said first face.

Preferably, said inwardly extending portion of the body comprises an annular flange.

.4r A N6 Preferably, the outer periphery of said body is configured to be engagable with a tool (such as a spanner) for applying torque to or otherwise manipulating the body portion.

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1 i i I 1 3 In another form the invention resides in a method for removing a sheared fixing element from a body in which it is at, least partially embedded comprising the following steps: Placing an extraction device of the type described adjacent to said fixing element such that said first face of the extraction device is adjacent said fixing element; securing said inwardly extending portion of the body of the extraction device to said fixing element; and manipulating said body to remove the sheared fixing element.

Where the fixing element is a threaded fixing element, the step of manipulating said body preferably comprises the 0 application of torque to the body to unscrew the threaded *e ~fixing element.

The invention will be better understood by reference to the following description of one specific embodiment thereof as shown in the accompanying drawings in which:- Fig. 1 is a top plan view of an extraction device; 0.* e m Fig. 2 is a side sectional view of the extraction device of Fig. 1; Fig. 3 is a side sectional view of the extraction device of Figs. 1 and 2, attached to a sheared fastening means; and Fig. 4 is a side sectional view of a sheared fastening means being removed.

The embodiment is directed towards a hollow element which contains a inwardly directing angular flange spaced inward from one face of the hollow element. The hollow element is placed against a sheared stud and spot welded to the stud along the periphery of the inner flange.

i_ ^tl 1 r.f)rtn~rw^(^ i* K s .T 2 4- The hollow element 10 comprises a body 10 which has first and second face 11 and 12 and which is hexagonally configured to be gripped by suitably sized spanner. The size of the hollow element will be dependent on the size of the sheared stud to be removed.

The hollow element is provided with a substantially cylindrical passageway 13 extending throughout the body of the hollow element. Contiguous to the first face 11 of the hollow element there is provided an inwardly directing angular flange 14 which extends from the inner wall of the passageway to a position such that the diameter of the S inner periphery of the angular flange is less than one kit# half of the diameter of the passageway at the other face.

In use, the hollow element is positioned on the face of a sheared stud 15 so that the first face of the hollow S element is positioned adjacent to the face of the stud. A suitably sized hollow element is chosen so that the diameter of the inner periphery of the angular flange is less than the diameter of the sheared stud (see Fig. 3).

The hollow element is fastened to the sheared stud by spot P. ~welding the inner periphery of the angular flange to the face of the sheared stud. When the weld 16 has cooled, the stud may be removed by rotating the hollow element.

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It will be appreciated that the hollow element according to the embodiment can be used to remove sheared fixing elements other than threaded studs and in particular can be used to remove fixing elements which do not incorporate screw threads. In the later case, the hollow element of this embodiment can be spot welded to the non-threaded fixing element and the fixing element extracted by manipulating the hollow element such as by twisting and pulling the hollow element.

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iL 4 5 Various other changes and modifications may be made to the embodiment described without departing from the present invention. For instance, the flange can be replaced with any type of inwardly projecting means such as protrudances, the sole requirement being the ability to spot weld or otherwise fix the hollow element to the face of the sheared fixing means.

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Claims (8)

1. 2. The device of claim 1 wherein the inwardly extending portion comprises an annular flange.
2. 3. The device of claims 1 or 2 wherein the outer periphery of the body is configured for engagement with a tool for manipulating the body. S0
3. 4. The device of claims 2 or 3 wherein the annular flange extends from the inner wall of the passageway such 54 that the size of the passageway through the inner periphery of the annular flange is less than one half of the diameter of the passageway at the other face.
4. 5. A method for removing a sheared fixing element from *5 5 a body in which it is at least partially embedded comprising the following steps: Positioning the extraction device of any one of the preceding claims adjacent to said fixing element such that said first face is adjacent said fixing element; securing said inwardly extending portion of the body to said fixing element; and manipulating said body to remove the sheared fixing element.
5. 6. The method of claim 5 where the inwardly extending Sportion is welded to the fixing element. A 7
6. 7. The method of claim 5 where the inwardly extending portion is soldered to the fixing element.
7. 8. An extraction device substantially as hereinbefore described with reference to the accompanying drawings.
8. 9. A method for removing a sheared fixing element substantially as hereinbefore described with reference to the accompanying drawings. DATED this first day of May, 1990 S BERTRAM HEWITT Applicant WRAY ASSOCIATES Perth, Western Australia Patent Attorneys for Applicant I I ICI "r a I.r Ir I i rISr 9 x- jl I i :I I S*ft11 V t