GB1573269A - Methods of making fork bolts and fork bolts so made - Google Patents

Description

(54) METHOD OF MAKING FORK BOLTS AND FORK BOLTS SO MADE (71) We, SCAFFOLDING SUPPLIES LIMITED, a British Company of Riverside Road, London SW17 OBE, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement-: This invention relates to fork bolts, that is bolts of the kind comprising a screwthreaded shank provided at one end with a pair of spaced parallel lugs directed away from the shank and each formed with a hole, the two holes being mutually aligned and extending transversely of the axis of the bolt. Fork bolts are used for many different purposes and are for example used in scaffolding.In normal use the shank is secured in place by means of a nut or nuts, and a component to be attached to the bolt is provided with a portion which is inserted between the lugs, that portion having a preformed hole which is aligned with the holes in the lugs, and a securing pin being inserted through the holes in the lugs and the hole in the portion of the component.

Hitherto some fork bolts have been made from forged blanks while others have been fabricated. The present invention aims to provide a simpler or less expensive method of manufacture than those normally used for production.

From one aspect the present invention consists in a- method of making a fork bolt in which there is provided a member comprising a shank provided with an axially projecting end portion, and a plate of elongated shape formed with an aperture spaced from its ends, the end portion of said member being inserted into the aperture and riveted to form a rivet head to secure the plate to the member, and those parts of the plate on either side of the aperture and riveted end portions being bent to form two spaced lugs projecting away from the shank, the said shank being screw-threaded before assembly of the member with the plate or subsequently, and holes being formed in the plate before assembly of the member with the plate or subsequently, the holes being such that in the completed bolt they are in the lugs and are mutually aligned transversely to the axis of the shank.

Preferably the shank is screw-threaded before the end portion of the member is inserted into the aperture for riveting.

The holes in the lugs are preferably formed in the plate before the plate is riveted to the member, though it would be possible in alternative methods to form the holes after the plate was riveted to the member and either before or after the plate is bent to form the two lugs.

In a preferred method of manufacture the rivet head is deformed by the lugs as they are bent up, the resultant engagement between the rivet and the adjacent parts of the lugs preventing or assisting in the prevention of relative rotation between the plate and the member. Further, it is preferred to weld the member to the underside of the plate, that is the side opposite to the side engaged by the rivet head. This also prevents relative rotation between the plate and the member as well as strengthening the bolt. Preferably the welding operation is carried out after the lugs have been bent up, for in this case the weld can fill the small gaps which may be produced between the shank and the plate, around the aperture, in consequence of the deformation of the part of the plate formed with the aperture which occurs during the bending operation.The welding operation could be an alternative to the deformation of the rivet head, but in a preferred method of manufacture the rivet is deformed and welding is also effected.

From another aspect the present invention consists in a fork bolt made by a method of the kind outlined above as being in accordance with one aspect of the present invention.

A fork bolt embodying the invention is illustrated, by way of example in the accompanying drawings, in which: Figure 1 is a front view of a screwthreaded member for incorporation in the fork bolt, Figure 2 is a plan view of a plate for incorporation in the fork bolt, Figure 3 is a front view of the screwthreaded member of Figure 1 and the plate of Figure 2 riveted together, Figure 4 is a front view of the completed fork bolt, and Figure 5 is a side view of the completed fork bolt.

In the manufacture of the fork bolt there are first produced a screw-threaded member 10 (Figure 1) and a plate 11 (Figure 2). Both are formed from steel.

The screw-threaded member 10 has a screw-threaded shank 12 with an axially extending end portion 13 of cylindrical shape and of smaller diameter than the shank. The plate 11 comprises a strip with rounded ends and formed with a central aperture 14 of the same nominal diameter as the end portion 13 of the member 10.

The plate 11 is also formed near its ends with two holes 15.

The end portion 13 is inserted into the aperture 14 and the projecting part thereof is subjected to a radial riveting operation which results in the formation of a rivet head 16 which serves to hold the plate 11 against the annular shoulder formed between the shank 12 and the end portion 13. The plate 11 is then bent by a pressing operation so that those parts of the plate on either side of the rivet head 16 are bent up to form two spaced, parallel lugs 17 projecting away from the shank 12. The arrangement is such that the two holes 15 are then mutually aligned and their common axis intersects the axis of the shank 12 and is at right angles to that axis.

In the bending operation the rivet head 16 is deformed, as shown at 18 so that the head is formed with parallel flats which engage the adjacent parts of the lugs and prevent relative rotation between the plate 11 and the member 10. Finally two fillet welds 19 are effected on the underside of the plate, securing the plate to the member and filling any small gaps that may have resulted from the bending up of the lugs.

In a modified construction, not illustrated, each end part of the plate 11 is so shaped as to provide an increased width of metal around the hole 15 formed in that end; in outline each end part is in the shape of about three-quarters of a circle, the circle having the same centre as the hole and having a diameter rather grater than the width of the central part of the plate.

WHAT WE CLAIM IS: 1. A method of making a fork bolt in which there is provided a member compris ing a shank provided with an axially pro jecting end portion, and a plate of elongated shape formed with an aperture spaced from its ends, the end portion of said member being inserted into the aperture and riveted to form a rivet head to secure the plate to the member, and those parts of the plate on either side of the aperture and riveted end portion being bent to form two spaced lugs projecting away from the shank, the said shank being screw-threaded before assembly of the member with the plate or subsequently, and holes being formed in the plate before assembly of the member with the plate or subsequently, the holes being such that in the completed bolt they are in the lugs and are mutually aligned transversely to the axis of the shank.

2. A method according to claim 1 in which the shank is screw-threaded before the end portion of the member is inserted into the aperture for riveting.

3. A method according to either of claims 1 and 2 in which the holes in the lugs are formed before the plate is riveted to the member.

4. A method according to any of claims 1 to 3 in which the rivet head is deformed by the lugs as they are bent up, the resultant engagement between the rivet head and the adjacent parts of the lugs preventing or assisting in the prevention of relative rotation between the plate and the member.

5. A method acording to any of claims 1 to 4 in which the member is welded to that side of the plate opposite to the side engaged by the rivet head.

6. A method according to claim 5 in which the welding is effected after the lugs have been bent up.

7. A method of making a fork bolt sub stantially as hereinbefore described with reference to the accompanying drawings.

8. A fork bolt made by a method according to any of the preceding claims.

9. A fork bolt according to claim 8 and

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. the shank and the plate, around the aperture, in consequence of the deformation of the part of the plate formed with the aperture which occurs during the bending operation. The welding operation could be an alternative to the deformation of the rivet head, but in a preferred method of manufacture the rivet is deformed and welding is also effected. From another aspect the present invention consists in a fork bolt made by a method of the kind outlined above as being in accordance with one aspect of the present invention. A fork bolt embodying the invention is illustrated, by way of example in the accompanying drawings, in which: Figure 1 is a front view of a screwthreaded member for incorporation in the fork bolt, Figure 2 is a plan view of a plate for incorporation in the fork bolt, Figure 3 is a front view of the screwthreaded member of Figure 1 and the plate of Figure 2 riveted together, Figure 4 is a front view of the completed fork bolt, and Figure 5 is a side view of the completed fork bolt. In the manufacture of the fork bolt there are first produced a screw-threaded member 10 (Figure 1) and a plate 11 (Figure 2). Both are formed from steel. The screw-threaded member 10 has a screw-threaded shank 12 with an axially extending end portion 13 of cylindrical shape and of smaller diameter than the shank. The plate 11 comprises a strip with rounded ends and formed with a central aperture 14 of the same nominal diameter as the end portion 13 of the member 10. The plate 11 is also formed near its ends with two holes 15. The end portion 13 is inserted into the aperture 14 and the projecting part thereof is subjected to a radial riveting operation which results in the formation of a rivet head 16 which serves to hold the plate 11 against the annular shoulder formed between the shank 12 and the end portion 13. The plate 11 is then bent by a pressing operation so that those parts of the plate on either side of the rivet head 16 are bent up to form two spaced, parallel lugs 17 projecting away from the shank 12. The arrangement is such that the two holes 15 are then mutually aligned and their common axis intersects the axis of the shank 12 and is at right angles to that axis. In the bending operation the rivet head 16 is deformed, as shown at 18 so that the head is formed with parallel flats which engage the adjacent parts of the lugs and prevent relative rotation between the plate 11 and the member 10. Finally two fillet welds 19 are effected on the underside of the plate, securing the plate to the member and filling any small gaps that may have resulted from the bending up of the lugs. In a modified construction, not illustrated, each end part of the plate 11 is so shaped as to provide an increased width of metal around the hole 15 formed in that end; in outline each end part is in the shape of about three-quarters of a circle, the circle having the same centre as the hole and having a diameter rather grater than the width of the central part of the plate. WHAT WE CLAIM IS:

1. A method of making a fork bolt in which there is provided a member compris ing a shank provided with an axially pro jecting end portion, and a plate of elongated shape formed with an aperture spaced from its ends, the end portion of said member being inserted into the aperture and riveted to form a rivet head to secure the plate to the member, and those parts of the plate on either side of the aperture and riveted end portion being bent to form two spaced lugs projecting away from the shank, the said shank being screw-threaded before assembly of the member with the plate or subsequently, and holes being formed in the plate before assembly of the member with the plate or subsequently, the holes being such that in the completed bolt they are in the lugs and are mutually aligned transversely to the axis of the shank.

2. A method according to claim 1 in which the shank is screw-threaded before the end portion of the member is inserted into the aperture for riveting.

3. A method according to either of claims 1 and 2 in which the holes in the lugs are formed before the plate is riveted to the member.

4. A method according to any of claims 1 to 3 in which the rivet head is deformed by the lugs as they are bent up, the resultant engagement between the rivet head and the adjacent parts of the lugs preventing or assisting in the prevention of relative rotation between the plate and the member.

5. A method acording to any of claims 1 to 4 in which the member is welded to that side of the plate opposite to the side engaged by the rivet head.

6. A method according to claim 5 in which the welding is effected after the lugs have been bent up.

7. A method of making a fork bolt sub stantially as hereinbefore described with reference to the accompanying drawings.

8. A fork bolt made by a method according to any of the preceding claims.

9. A fork bolt according to claim 8 and

substantially as hereinbefore described with reference to and as shown in the accompanying drawings.