GB2061440A

GB2061440A - Fastener Device

Info

Publication number: GB2061440A
Application number: GB8033590A
Authority: GB
Original assignee: Henry Lindsay Ltd
Current assignee: Henry Lindsay Ltd
Priority date: 1979-06-11
Filing date: 1979-06-11
Publication date: 1981-05-13

Abstract

The fastener device comprises a tubular member (30) which is taken through aligned holes in two parts (31, 32) which are to be fastened together, and which is slotted so as to be radially expandible by an externally threaded core member (38) which extends through the tubular member (30) and engages an internally threaded core head (37) to draw the latter into the tubular member (30) when the core member (38) is rotated. Lugs project from the core head (37) to engage in the slots in the tubular member (30) to prevent rotation of the core head (37). A resilient retaining ring (40) engages the outer periphery of the tubular member (30) and the lugs to hold the core head (37) in assembly with the tubular member (30) prior to use. <IMAGE>

Description

SPECIFICATION Fastener Device This invention relates to a fastener device for fastening two or more parts together.

According to the invention, there is provided a fastener device for fastening two or more parts together comprising: a tubular member which can be taken through aligned holes in two components to be fastened together; an integral head provided at one end of said tubular member to engage the surface surrounding the entrance to one of said holes; slots formed in said tubular member and extending from the end thereof remote from said one end and towards said head; an externally threaded core member which can be taken through the tubular member; an internally threaded core head engageable externally with said remote end of the tubular member and engageable internally by said core member so that the latter can move the core head axially into engagement with said remote end and towards the head of the tubular member so as to deform the tubular member radially outwardly;; lugs projecting from said core head to engage each in a respective one of said slots so as to oppose rotation of the core head relative to the tubular member, at least during initial movement of the core head towards the head of the tubular member; and a resilient retaining ring engaging with the outer periphery of said tubular member, near said remote end thereof, and with said lugs so as radially to constrain the lugs and to resist axial movement of the core head away from said head of the tubular member whereby the core head and the tubular member remain coupled together when not in service, and prior to said radial deformation of the tubular member.

The externally threaded core member may comprise a stud or a bolt, as desired. A nut threaded on the core member can engage the head of the tubular member and, upon tightening, can cause the core member to draw the core head axially of the tubular member.

Conveniently, each lug projects generally axially from the outer periphery of the core head and has a radial depth substantially equal to the radial depth of the corresponding slot in the tubular member.

A seating for the resilient retaining ring may be formed in the outer periphery of the tubular member, comprising a generally annular groove, which extends around the periphery of the tubular member between successive slots.

Preferably, each lug has a depression, which forms a continuation of the annular groove when the lug is received in the corresponding slot, whereby the lug is constrained radially inwardly by the retaining ring, and also is held so as to resist axial movement of the core head.

Conveniently, the retaining ring may take the form of a split ring which is fabricated simply and cheaply. In this respect, it should be borne in mind that the function of the retaining ring is to hold together the core head and the tubular member, before they are used on site, and to resist any initial tendency of the core head to rotate as it moves into engagement with the remote end of the tubular member. When the core head expands the tubular member radially, the retaining ring will be disengaged from its seating, but by this time the core head will have strong frictional engagement with the tubular member which will resist any subsequent tendency of the core head to rotate relative to the tubular member.

In order to resist any tendency for the tubular member to rotate in a hole or holes in one or two parts respectively, the outer periphery of the tubular member, adjacent to the head of the tubular member, may have one or more radial projections which are engageable with the edge or edges of the hole or holes.

A fastener device according to the invention is particularly suitable for use in fastening components to hollow steel sections, in which access cannot readily be had to the interior of the hollow sections.

One embodiment of fastener device according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawings in which Figure 1 is a longitudinal sectional view of the fastener device; Figure 2 is an end view of a tubular member of the fastener device; and Figure 3 is an end view of part of a core member of the fastener device.

Referring now to the drawings, there is shown an embodiment of fastener device for fastening two or more parts together. The fastener device comprises a tubular member 30 which can be taken through aligned holes in two components 31 and 32 which are to be fastened together, the tubular member 30 having an integral head 33 provided at one end to engage the surface 34 surrounding the entrance to the hole in the part 31. Evidently, if desired, a single plate may be accommodated in some or all of the space occupied by components 31 and 32.

Slots 35 are formed in the tubular member 30 and extend axially from an end 36 of the tubular member 30 and towards the head 33. The slots 35 enable the tubular member to be radially outwardly deformed by the core head 37, as will be explained in more detail below. An externally threaded core member 38 can be taken through the tubular member 30 and may take the form of a stud or bolt, as required. The core member 38 passes with clearance through a plane bore in the tubular member 30, and engages with an internal screw thread provided in the core head 37.

The core head 37 is frusto-conical and, upon axial movement of the core member 38 and the core head 37 to the left, as seen in Figure 1, (by rotation of the head of a bolt, or a nut on a stud, when the core member 38 is a bolt or a stud respectively), the core head 37 moves into deforming-engagement with the end 36 of the tubular member 30 so as to deform the latter radially outwardly.

In addition to enabling radially outward deformation of the tubular member 30, the slots 35 also have a holding function with respect to the core head 37. Thus, the core head 37 is provided with a number of axially extending lugs which correspond in number and position to the slots 35, so that each slot 35 can receive a respective lug. The core head 37 is shown in Figure 3, to a reduced scale as compared with Figures 1 and 2, and has three equally circumferentially spaced lugs 39. The lugs 39 project axially from the outer periphery of the core head 37 to be received in respective ones of the slots 35. The radial depth of the lugs 39 is substantially the same as the radial depth of the respective slots 35, and the engagement of each lug 39 in a respective slot 35 prevents rotation of the core head 37 relative to the tubular member 30.Evidently, there will be a tendency for the core head 37 to rotate when the core member 38 is threaded into the core head 37. Also, if the core member 38 should be rotated with a view to moving the core head 37 axially in the direction towards the head 33 of the tubular member 30, this also would tend to rotate the core head 37.

For convenience in handling and storage, it is intended that the tubular member 30 and the core head 37 should be capable of being maintained in an assembled form. To this end, a resilient retaining ring 30 is provided which engages with the outer periphery of the tubular member 30, near the end 36, and with the lugs 39 so as radially to constrain the lugs and to resist axial movement of the core head 37 in a direction away from the head 33 and the end 36 of the tubular member 30. A seating is provided in the outer periphery of the tubular member 30 and comprises a generally annular groove 41 which extends around the periphery of the tubular member 30 between successive ones of the slots 35. Each lug 39, which is received in a respective slot 35, has a depression which mates with the annular groove 41 so as to form a continuation thereof.Conveniently, the resilient retaining ring 40 comprises a split ring.

Evidently, when the core head 37 moves axially to the left in Figure 1 , from the position shown in the upper part of Figure 1 to the position shown at 37a in the lower part of Figure 1, the retaining ring 40 will become unseated, or will no longer engage with the depressions provided on lugs 39. However, the lugs 39 may remain engaged in the slots 35, through additional resistance to rotation of the core head 37 will be provided by virtue of the strong frictional contact between the frusto-conical engaging surface 42 of the core head 37 with the internal surface of the tubular member 30.

In order to resist rotation of the tubular member 30 in the aligned holes in the parts 31 and 32, as shown in Figure 2, radially outward projections 43 may be provided on the outer periphery of the tubular member 30, extending up to the head 33.

The fastener device may be used to enable two parts to be assembled in a factory, to be dissassembled by dismounting one of the parts while retaining the fastener device in position in the other of the parts, and to be subsequently reassembled on site in simple manner by remounting the dismounted part on the fastener device. However, the fastener device is also particularly suitable for use with hollow steel sections. With such use, it is desirable to prevent access of water to the interior of the hollow section, so that it is preferred that the head 33 should be formed with an annular groove 44 in which a sealing ring can be housed.

Claims

1. A fastener device for fastening two or more parts together comprising: a tubular member which can be taken through aligned holes in two components to be fastened together; an integral head provided at one end of said tubular member to engage the surface surrounding the entrance to one of said holes; slots formed in said tubular member and extending from the end thereof remote from said one end and towards said head; an externally threaded core member which can be taken through the tubular member; an internally threaded core head engageable externally with said remote end of the tubular member and engageable internally by said core member so that the latter can move the core head axially into engagement with said remote end and towards the head of the tubular member so as to deform the tubular member radially outwardly;; lugs projecting from said core head to engage each in a respective one of said slots so as to oppose rotation of the core head relative to the tubular member, at least during initial movement of the core head towards the head of the tubular member; and a resilient retaining ring engaging with the outer periphery of said tubular member, near said remote end thereof, and with said lugs so as radially to constrain the lugs and to resist axial movement of the core head away from said head of the tubular member whereby the core head and the tubular member remain coupled together when not in service, and prior to said radial deformation of the tubular member.

2. A fastener device according to Claim 1, in which said externally threaded core member comprises a stud or a bolt.

3. A fastener device according to Claim 1 or 2, in which each lug projects generally axially from the outer periphery of said core head and has a radial depth substantially equal to the radial depth of the corresponding slot in said tubular member.

4. A fastener device according to any one of the preceding claims, in which a seating for said resilient retaining ring is formed in the outer periphery of said tubular member.

5. A fastener device according to Claim 4, in which said seating comprises a generally annular groove which extends around the periphery of the tubular member between successive slots.

6. A fastener device according to Claim 5, in which each lug has a depression which forms a continuation of said annular groove when the lug is received in a corresponding slot, whereby the lug is constrained radially inwardly by said retaining ring and also is held so as to resist axial movement of the core head.

7. A fastener device according to any one of the preceding claims, in which said retaining ring takes the form of a split ring.

8. A fastener device according to any one of the preceding claims, in which the outer periphery of said tubular member, adjacent to the head of the tubular member, has one or more radial projections which are engageable with the edge of a hole in a component so as to resist rotation of the tubular member relative to the hole.

9. A fastener device according to Claim 1 and substantially as hereinbefore described with reference to, and as shown in Figures 1 to 3 of the accompanying drawings.