GB2229217A

GB2229217A - Fixing bolt

Info

Publication number: GB2229217A
Application number: GB8906057A
Authority: GB
Inventors: Andrew Charles Owens
Original assignee: ALTO SYSTEMS Ltd
Current assignee: ALTO SYSTEMS Ltd
Priority date: 1989-03-16
Filing date: 1989-03-16
Publication date: 1990-09-19
Anticipated expiration: 2009-03-16
Also published as: GB8906057D0; GB2229217B

Abstract

The bolt for releasably interconnecting apertured components e.g. of a temporary or dismountable structure has a body portion (4) to be located in the component aperture or apertures, a distal end having a recess or groove (6) which receives a captive ring (8) mounted for limited lateral sliding whereby it can be displaced out of alignment with the body periphery so preventing withdrawal of the bolt from the aperture or apertures. Conveniently the end of the bolt beyond the groove is of reduced diameter and may have a chamfered conical or hemispherical portion (10) at its tip to facilitate entry into the aperture or apertures, and the ring is also tapered or chafered for self alignment on assembly. In assembly the ring (8) drops under gravity to provide a projection below body portion (4). A cylindrical tool (20) is provided to facilitate disassembly. The tool may incorporate grooves or facet (24) mating with corresponding formations of the distal end so that only the correct tool will effect disassembly for greater security. <IMAGE>

Description

FIXING GOLT FOR DISM@UNTABLE STRUCTURES Temporary structures are oncoming much more commonplace and are used for many purposes typically.

scaffolding, grandstands and viewing galleries personnel barriers and tower cranes.

All of these structures are held together by fixing pins or by bolts and nuts which are often time consuming to install securely and which may be removed easily by vandals or unauthorised persons with a consequent high risk to persons and property.

The object of the present invention is to provide a toxins bolt which can be inserted readily through existing fixing holes and which is self-securing without the use of tools. In the prererred form the bolt cannot be removed easily without the use of a specialised key thus reducing the risks associated ith vandalism ano theft.

According to the invention a fixing bolt comprises an elongate body to be located in an aperture or alis-ned apertures of a component or components to be connected thereby, a distal end portion of the body having â peripheral groove or recess, and a locking ring captive in said groove or recess for limited lateral sliin- movement whereby it can be displaced out of alignment with the body periphery to prevent withdrawal of the bolt from said aperture or apertures in use.

Preferably the distal extremity of the body beyond said groove or recess is of lesser girth than that of the remainder of the body and the tip of said extremity may be chamfered, conical or part spherical to facilitate entry of the bolt into said aperture or apertures.

The periphery of the locking ring may also be chamfered or part conical so that it is self aligning with the body periphery on insertion into said aperture or apertures but resists axial withdrawal in the opposite longitudinal direction. a removal tool being provided which will fit over said distal extremity to coact with said chamfered or part conical periphery to re- align it with the body when the bolt is to be withdrawn for oisconnection of the component or components.

The bolt may have a head d proximal end so that it forms an integral fixing element, or its proximal end may form part of a component in the manner of a stud or spigot so that it is operably integral therewith for attachment of a further component or components thereto.

rl example of the invention will now be described with reference to the accompanying drawings in which Fi9.1 is an isometric view of the bolt9 rig.2 shows sieve and end elevations of the bolt, Fig.3 shows the oPeration or the removal key, and Fig.4 shows the security ki including the grooving and/or faceting.

The invention comprises of a bolt (2) having 2 cylindrical body portion (4) of sufficient length to p355 through the components to be connected. At least one end of the bolt incorporates a recessed portion () onto which is fitted a circular ring (8) and may incorporate 2 chamfered, conical, or hemispherical portion (10) at the extreme end of the bolt.

The ring has an external diameter similar in size to the body portion but has an internal cylindrical surface (12) such that the ring is a loose fit diametrically on the recessed portion of the bolt. The ring incorporates a conically tapered face (14).

The removal tool comprises of a cylindrical rod (20) similar in external diameter to the bolt and incorporating a recessed portion (22) at one end so shaped as to receive the distal end of the bolt and to cause the ring portion to become axially aligned with the bolt. The shaped end (10) may incorporate grooves or facets (16) around the periphery in such a pattern as to create a unique arrangement, the removal tool (20) must similarly incorporate identical grooves or facets (24), thus providing a unique security key.

In operation the conical end of the bolt is passed through the components to be connected causing the chamfering ring to become axially aligned with the bolt permitting the bolt to pass freely through the connecting holes. Once the bolt end emerges from the series of holes the ring, which is a loose fit on the bolt recess, drops down by the action of gravity thus providing a semicircular projection (18) below the bolt. preventing its subsequent withdrawal.

Where the bolt passes through components having voids within the connecting holes. the bolt becomes secure even if only partially inserted through the joint.

Removal of the bolt is effected by insertinc th tool over the end of the bolt such that the rine is caused to become axially aligned with the bolt. The bolt may then be pushed out using the extraction tool.

Claims

1. A fixing bolt comprising an elongate body to be located in an aperture or aligned apertures of one or more components to be connected or secured thereby, a distal end portion of the body having a peripheral groove or recess; and a locking ring captive in said groove or recess for limited lateral sliding movement whereby it can be displaced out of alignment with the periphery of the body to resist withdrawal of the bolt from said aperture or apertures in use.

2. A bolt as in Claim 1 wherein the distal extremity the body beyond said groove or recess is of lesser gir-.- than that of the remainder of the body.

3. h bolt as in Claim 1 or 2 wherein the periphery o,~ the locking ring is chamfered or part conical witl its lesser diameter end directed towards the distal extremity of the body whereby the rinks is self-aligninu with the body periphery on insertion of the distal end portion the body into said aperture or apertures but, on said displacement, resists axial withdrawal in the opposit longitudinal direction.

4. The combination of a bolt as in Claim 3 ann a cylindrical removal tool formed to fit over the distal extremity of the bolt body to coact with the periphe+, the locking ring to re-align the ring with the body T facilitating withdrawal of the bolt from the aperture or apertures when disconnection of said component or components is required.

5. A combination as in Claim 4 wherein the tool and said distal extremity are provided with complementary grooves or facets in a predetermined matching pattern whereby only a correctly formed tool can be employed to effect said re-alignment.

6. A bolt, or bolt and tool combination. as in any preceding claim wherein the tip of the distal end portion of the bolt body is chamfered, conical or part spheric-ul to facilitate entry into said aperture or apertures.

7. A bolt, or a combination of a bolt and tool, as in any preceding claim wherein the bolt has a headed proximal end to act as an integral fixing element.

8. A bolt, or a combination of a bolt and a tool, ac ln as any one of Claims 1 to 6 wherein a proximal end of t bolt is operatively fast with a further component in 1 manner of a stud or spigot operable for connection therewith of said one or more components having said aperture or apertures thereto.

9. A fixing bolt substantially as hereinbefore described with reference to and as shown in Figures 1 3 of the accompanying drawings.

10. A combination of a fixing bolt and a removal tool substantially as hereinbefore described with reference t and as shown in the accompanying drawings.

11. An assembly or structure including a plurality of components operatively connected by one or more bolts 2s in any preceding claim.