AU2008201679B2

AU2008201679B2 - Improved screw (separate wing)

Info

Publication number: AU2008201679B2
Application number: AU2008201679A
Authority: AU
Inventors: Given Not
Original assignee: Loi & Tran Pty Ltd
Current assignee: Loi & Tran Pty Ltd
Priority date: 2007-04-18
Filing date: 2008-04-17
Publication date: 2014-10-02
Anticipated expiration: 2028-04-17
Also published as: AU2008201679A1

Abstract

-13 A roofing screw having a body, an elongated thread on the body, means on one end of the body whereby roofing materials may be pierced, means on the other end of the body whereby the screw can be rotated, and a sleeve passing over the body and terminating close to the other end whereby the screw can be rotated and having at least one outwardly extending member whereby when the screw is screwed into and through a roofing sheet, the outwardly extending member forms an aperture which has a diameter greater than the diameter of the screw. In one form the sleeve has an internal thread which corresponds to the thread on the body so it can be connected thereto by being screwed onto the body. The sleeve may have at least two radially outwardly extending members each of which is formed at its outwardly extending edge to form the enlarged aperture. Y:\SPEC\Loi & Tran SeparateWing complete 130408.wpd AT/CM 15/4/08 51, 60 K'62

Description

Regulation 3.2 -1 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT APPLICANT: Loi & Tran Pty. Limited NUMBER: FILING DATE: Invention Title: IMPROVED SCREW (SEPARATE WING) The following statement is a full description of this invention, including the best method of performing it known to me: -2 IMPROVED SCREW (SEPARATE WING) Technical Area This invention relates to an improved screw and, in particular, to an improved screw of the type described and illustrated in our Australian Patent Application 2002214828 which was based on PCT patent application PCT/AU2001/01485 and entitled, "Cutting Screw". Background to the Invention That screw has been extremely successful in the market-place, in that when it is necessary to fix a roofing sheet to a batten, it is desirable that the aperture in the roofing sheet be larger than the diameter of the screw by means of which it is held, so that if there is any relative movement between the sheet and the frame, then it is unlikely that the sheet will suffer from stress fracturing. Whilst technically the previous screw completely overcame the immediate problem of protecting the sheet, it did have a disadvantage in manufacture, in that, to make a good seal about the aperture, roofing screws of this type have a generally cupped washer which locates under an extension on the head of the screw and, when the screw is tightened, conforms to the shape of the sheet to Y:\SPECLoi &Tran SeparaleWing complete 130408.wpd AT/CM 15/4/08 -3 which the screw is attached and with the previous screw, there was a difficulty in manufacture, in that the washer had to be substantially distorted to be placed over the extending wings on the screw. Also, as the screws were made in very large numbers and the manufacturing process is fast, there could be difficulties in forming the wings accurately. Outline of the Invention It is the object of the invention to provide a screw which, in operation, is equally satisfactory to the prior screw, but which is simpler to manufacture. The invention includes a roofing screw having a body, an elongated thread on the body, means on one end of the body whereby roofing materials may be pierced, means on the other end of the body whereby the screw can be rotated, and a sleeve passing over the body and terminating close to the end whereby the screw can be rotated and having at least one outwardly extending member whereby when the screw is screwed into and through a roofing sheet, the outwardly extending member forms an aperture which has a diameter greater than the diameter of the screw. It is preferred that the sleeve has an internal thread which corresponds to the thread on the body so that the sleeve can be connected thereto by being Y:\SPEC\Loi & Tran SeparaleWing complete 130408.wpd AT/CM 15/4/08 -4 screwed onto the body. It is preferred that there are at least two radially outwardly extending members each of which is formed at its outwardly extending edge to form the enlarged aperture. Preferably each outwardly directed member has a downwardly directed cutting member located radially outwardly from the body of the screw. The extending members on the threaded sleeve may be similar to those described in our previous patent application, that is, they may extend outwardly from the body of the sleeve and have a generally downwardly-directed, lower cutting tip, or they could be formed in a manner to ream an enlargement of the hole through which the body of the screw has passed. The screw may preferably have a resilient washer which can be passed over the body from the piercing end prior to the sleeve being fitted thereto. Description of an Embodiment of the Invention In order that the invention may be more readily understood, there shall be described particular forms of the screw of the invention, the description being based on the accompanying drawing, in which one embodiment of the screw is shown in an exploded view.. Y:\SPEC\Loi & Tran SeparateWing complete 130408.wpd AT/CM 15/4/08 -5 In each of these forms, the screw has a cylindrical body 58 of a required length, which body is formed with a screw thread 51 over at least a major portion of its length. In one particular form, which is designed for use with metal sheets and battens, one end of the body can be provided with a drill tip 53 which would normally have two cut-out portions 54 and a shaped tip 56 which is adapted to act to drill through metal members. In another embodiment, the tip may be tapered to a point with the thread extending effectively the whole of the length of the drill which is of a conventional form for use with wooden battens and in a still further form, the tip may be a composite tip which has the features both of a drill-tip, in having the cut-out portion, and the wood-entering screw with thread portions extending almost to the outer end. The particular form of tip is known and can be varied, depending upon required applications. The other end of the body is provided with a hexagonal or other shaped head 52 to enable driving tools to be connected thereto and, as the screw will normally be used for fixing roof members, it is preferred that the end be formed to receive a socket or the like on an electric or pneumatic drill or screw driver. YASPECLol & Tran SeparateWing complete 130408.wpd AT/CM 15/4/08 -6 Beneath the head there is preferably an extended outward portion 57 which acts as a rest for a washer 70, as will be described, and may preferably be formed integrally with the head. There is formed , for use in association with the screw, a sleeve member 66 which has a body 60 which has an internal thread 61 which is adapted to co operate with the thread 51 on the screw. On its periphery the sleeve 60 has at a pair of outwardly-directed member 62 which are adapted to form an aperture in the roofing sheet which is larger in diameter than the diameter of the screw to permit thermal expansion of the roofing sheet without placing pressure on the sheet as would be the case if the screw was a close fit to the aperture. In the illustrated embodiment, the members 62 each have a downwardly directed cutting member 63 located radially outward from the body of the screw. If required, the sleeve culd be formed by casting and it is possible to have more than two members 62. Also, the form of members can vary. It would be possible for them to be wedge shaped to effectively ream a larger diameter hole rather than to cut a larger diameter hole ot could be basically rectangular with a cutting edge n the lower surface thereof. Y:\SPEC\Loi & Tran SeparateWing complete 130408.wpd AT/CM 15/4/08 -7 The arrangement of the invention lets the screw to be formed in the normal way for screws of this type and a washer to be connected to the screw and located on the under-side of the extension of the head before the sleeve is fitted and without the necessity of any substantial distortion. The sleeve 66 can then be screwed onto the body and whilst this may be screwed along the length of the thread, which would normally cease where it was required that the collar be located, it could also be simply screwed onto the end of the thread and move along the thread automatically when the screw is being used. Alternatively, the sleeve could have a bore slightly greater than the diameter of the body of the screw so as to be able to be passed thereover and to make a frictional fit with an upper portion of the screw. In use, the first described form of the sleeve, there is a pair of outwardly-directed wings similar to those used in our Winfix screw, that is to say that the wings extend outwardly and have at their outer end a downwardly-directed portion which is adapted to act at a cutting edge against the sheet material through which the screw is to be passed and, on rotation of the screw together with the downward movement thereof, a circular aperture is formed with the cut-out portion either breaking and falling away, or remaining around the periphery of the screw body. Y:\SPEC\Loi & Tran SeparateWing complete 130408.wpd AT/CM 15/4/08 -8 This portion passes through the roofing-sheet and when the screw reaches its fully inserted position, that is, when the washer is in good contact with the top of the roofing sheet, then the collar is located beneath the upper surface of the roofing sheet. Similarly with the other forms of the invention, the members which extend from the sleeve rotate and are caused to move through the sheet because of the rotation and downward movement of the screw and these members, as stated above act to ream out the hole. With the form of device on the collar, there can be 2, 3 or 4 of these triangular blades which can give an effective reaming action. Again, in this embodiment, the blades are, when the screw is fully located, beneath the aperture in the roofing sheet, and above the batten into which the body of the screw is passed. It will be appreciated that at either embodiment the cutting edges can be formed to give optimum cut when the cutting members contact the roofing sheet, which is normally of a polycarbonate glass fibre or the like. Whilst we have described in this application various aspects of the invention, it is to be understood that variations and modifications, particularly in the forms of Y:\SPEC\Loi & Tran SeparareWing complete 130408.wpd AT/CM 15/4/08 -9 the cutting members associated with the sleeve, can readily be used. Y:\SPEC\Loi & Tran SeparateWing complete 130408.wpd AT/CM 1514/08

Claims

1. A roofing screw having a body, an elongated thread on the body, means on one end of the body whereby roofing materials may be pierced, means on the other end of the body whereby the screw can be rotated, and a sleeve having an internal thread which corresponds to the elongated thread on the body to facilitate screwing of the sleeve onto said body so as to be passed over the body to be positioned adjacent the end whereby the screw can be rotated and having at least one outwardly extending member whereby when the screw is screwed into and through a roofing sheet, the outwardly extending member forms an aperture which has a diameter greater than the diameter of the screw.

2. A roofing screw as claimed in claim 1 wherein the sleeve is removably mounted on said body.

3. A roofing screw as claimed in claim 1 or claim 2 wherein there are at least two radially outwardly extending members each of which is formed at its outwardly extending edge to form the enlarged aperture.

4. A roofing screw as claimed in claim 3 wherein each outwardly extending member has a downwardly directed cutting member located radially outwardly from the body of the screw.

5. A roofing screw as claimed in claim 3 wherein each outwardly extending member is formed so as to effect a reaming operation which enlarges the aperture. 11

6. A roofing screw as claimed in claim 5 wherein the outwardly extending members taper from their end close to the thread to the end closer to the end whereby the screw can be rotated.

7. A roofing screw as claimed in any preceding claim wherein there is a resilient washer placed on the body prior to the sleeve being placed thereon.

8. A roofing screw substantially as hereinbefore described with reference to the accompanying drawing.