GB2172369A - Nut and bolt assembly - Google Patents

Abstract

A nut comprising a piece of material which may be cropped from a metallic strip so as to be of square or rectangular configuration, said material being shaped into a developable form such as a part-cylindrical form and being pierced to provide an aperture which is then plunged to push out material around the aperture, thus providing an aperture having an axial length which is greater than the thickness of the original material. The interior of the plunged aperture is then formed with a screw thread 22. <IMAGE>

Description

SPECIFICATION Nut and bolt assembly This invention relates to a nut and bolt assembly which is especially (but not exclusively) intended for use in a scaffolding fitting such as a sleeve connector which is arranged in use to connect together two elongate scaffolding members (such as a pair of scaffolding tubes) in a co-axial, end-toend relationship.

Such a connector may be in the form of a split sleeve which is of a generally U-shaped configuration in cross-section but in which the portions of the sleeve adjacent to its free edges are turned outwardly to provide, on such portions, exterior surfaces which are of concave configuration. In use, adjacent ends of the two elongate scaffolding members to be connected together are inserted into opposite ends of the sleeve and the latter is then contracted into clamping engagement with said members by means of a pair of nut and bolt assemblies disposed respectively at opposite ends of the sleeve, the bolt of each assembly extending through a pair of aligned holes respectively formed in said two outwardly turned portions of the sleeve adjacent its free edges.The aforesaid concave exterior surface of one of said portions provides a seating for the nut of a nut and bolt assembly and one object of the present invention is to provide, in an inexpensive form, a nut which can be used in such a seating although it is to be understood that the nut can also be used in other applications if desired.

In accordance with the invention there is provided a nut which is formed from a flat imperforate piece of metallic material which is pierced to provide an aperture and shaped to a developable form, the portion of material around said aperture then being pushed outwardly to project from one surface of said piece in order to form an aperture having an overall axial length which is greater than the original thickness of the material and which is subsequently formed with a screw thread.

The nut is conveniently formed from a piece of material (which may be of square or rectangular configuration) cropped from a metallic strip and the developable form into which it is shaped may be of part-cylindrical or any other convenient form.

The aperture is then preferably plunged to push out material around the aperture so that such material projects from one surface, preferably the concave surface, of the nut.

Any suitable and known form of bolt may be used with a nut which is formed as above-described but in one convenient and novel embodiment (as described in our prior patent 2,039,233) the bolt is formed from a length of cylindrical rod which is provided at one end with a external screw thread and at the other end with a part spherical head (as by means of a forging or a cold-heading operation) which is then flattened to a disc-like form and pierced to form in the flattened end a non-circular aperture adapted to receive the end of a tool which has a cross-sectional configuration similar to that of the aperture and which can be inserted into the aperture for the purpose of turning the bolt.

The invention will now be more particularly described with reference to the accompanyng drawing wherein Figure 1 is aperspective view of a scaffolding fitting (which in this instance is a sleeve connector intended for use in connecting together two elongate scaffolding members in a co-axial, end-to-end relationship) incorporating examples of nuts formed in accordance with the invention, and Figures 2-5 are perspective views which show respectively different stages in forming the nuts which are seen in Figure 1.

Referring now to the drawings there is shown in Figure 1 a sleeve connector which is intended for use in connecting together a pair of elongate scaffolding members (such as a pair of scaffolding tubes) (not shown) in a co-axial end-to-end relationship and such sleeve connector comprises a split sleeve 10 which in use is arranged at its opposite ends to embrace the adjacent ends of said scaffolding members. There is also provided a partition 11 which extends across the interior of said sleeve, said partition having a pair of oppositely disposed outwardly directed projections which extend respectively through a pair of oppositely disposed slots formed in the sleeve (one of such slots being indicated by reference numeral 12 in Figure 1) for the purpose of locating the partition within the sleeve.In use the adjacent end surfaces of the two scaffolding members to be connected will abut the opposite surfaces of said partition.

As will be inferred from Figure 1 said split sleeve 10 is of generally U-shaped configuration in crosssection but the portions of said sleeve adjacent to its free edges namely portions 13 and 14 are turned outwardly to provide on such portions exterior surfaces which are of concave configuration.

There is also provided a pair of nut and bolt assemblies which each comprise a bolt 15 and a nut 16 said assemblies being disposed respectively adjacent to the opposite ends of the sleeve and in use tightening of each nut 16 relative to its bolt 15 will have the effect of contracting the associated end of the sleeve onto one of the two scaffolding members which will have been assembled to the sleeve by inserting their adjacent ends into the interior of the sleeve. The interior surface of the sleeve will then be forced into a gripping relationship with the exterior surfaces of the scaffolding members and will thus secure them in a co-axial end-to-end relationship.

Turning now to Figures 2-5 each of the nuts 16 shown in Figure 1 is formd from a piece of material indicated in Figure 2 by reference numeral 17 which is of square or rectangular configuration and which is conveniently cropped from a metallic bar or strip. Such piece of material 17 is then formed by a press tool into a developable form to provide a curved configuration indicated by reference numeral 18 in Figure 3 whilst at the same time a central aperture indicated by reference numeral 19 is also formed. In the next stage, illustrated in Figure 4, the central hole 19 is enlarged and also "plunged" as indicated by reference numeral 20 in Figure 4 so that material is pushed out around the aperture (now indicated by reference numeral 21) so that such material projects one surface, preferably the concave surface as shown.Such an arrangement provides an axial length of the aperture 21 which is greater than the original thickness of the material 17. Finally, as illustrated in Figure 5 the aperture 21 is tapped to form an internal screw thread 22 and this completes in an inexpensive but effective manner the formation of the nut 16.

The generally curved configuration of each nut 16 enables it to fit snugly into the concave part of the exterior of the sleeve 10 adjacent to one of the free edges thereof, such concave exterior surface of the sleeve engaging the convex surface of the nut and once the nut has been sufficiently tightened on the associated bolt 15 the inter-engagement of such concave and convex surfaces will prevent any inadvertent further rotation of the nut.

Tightening of each nut and bolt assembly is in fact effected by turning the head 23 of each bolt which is formed, as will be seen from Figure 1 with a non-circular (in this case square) aperture 24.

Conveniently each bolt 15 is formed from a short length of rod material which is formed at one end, as by means of a forging or a cold-heading operation, with a part-spherical head which is then flattened to a generally disc-like configuration as is indicated by the aforesaid reference numeral 23.

Piercing of said flattened head 23 is then effected to form the aforesaid non-circular aperture 24 which is thus adapted to receive the end of a tool of similar cross-sectional configuration whereby the tool can be used to rotate the bolt and thereby contract the sleeve 10 as above described. Each nut and bolt assembly also includes a plain washer 25 and a further washer which is formed integrally with a pair of spaced parallel lips or flanges which project in directions parallel to the axis of the associated bolt 15 and which in use are arranged so that their free edges engage in suitable recesses formed in the exterior surface of said U-shaped portions of the sleeve 10. Thus on tightening of each bolt 15 by applying the aforementioned tool to the aperture 24 in the flattened head 23 the nut at one end of each bolt assembly and the aforementioned lips or flanges of the flanged washer at the other end of the assembly will respectively contact the exteriors of the opposite sides of the split sleeve in order to effect contraction thereof and the consequent clamping engagement of a scaffolding member inserted into the sleeve.

As above described the aforementioned nut and bolt have been applied to a sleeve connector but it is also to be understood that a nut constructed in accordance with the present invention can be used in other applications, such as other scaffolding fittings, instead.

Claims (7)

1. A nut which is formed from a flat imperforate piece of metallic material which is pierced to provide an aperture and shaped to a developable form, the portion of material around said aperture being pushed outwardly to project from one surface of said piece in order to form an aperture having an overall axial length which is greater than the original thickness of the material and which is subsequently formed with a screw thread.

2. A nut as claimed in Claim 1 which is formed from a piece of material of square or rectangular configuration.

3. A nut as claimed in Claim 1 or Claim 2 in which the developable form into which said material is shaped is of part-cylindrical configuration.

4. A nut as claimed in any one of the preceding claims wherein said aperture is plunged to push out material around the aperture.

5. A nut as claimed in Claim 4 when dependent upon Claim 3 wherein the material which is pushed out around the aperture projects from the concave surface of the nut.

6. A nut as claimed in any one of the preceding claims in combination with a bolt which is formed from a length of cylindrical rod which is provided at one end with an external screw thread and at the other end with a part-spherical head which is flattened to a disc-like form and pierced to form in the flattened end a non-circular aperture adapted to receive the end of a tool for the purpose of turning the bolt.

7. A nut substantially as hereinbefore described with reference to and as shown in the accompanying drawing.