GB2207689A - Adjustable strut with ball and socket joints for use in archwork structures - Google Patents

Abstract

Disclosed is a telescopic strut member for spanning between parallel girders in a roof supporting archwork structure in mining or tunnelling. Two elements forming the strut have U-shaped cross sections and one element is designed to be slidingly received within the other. Two U-shaped bolt clamps 4 and 5 are provided to lock the elements together to prevent relative movement therebetween and to provide a strut of predetermined length. The means for attaching each end of the strut member to a respective girder comprises two elements, one for securing to the girder and the other to the end of the strut, the two elements being linked by a ball 65 and socket 62 arrangement whereby they are articulably connected. <IMAGE>

Description

ADJUSTABLE STRUT FOR USE IN ARCHWORK STRUCTURES The present invention relates to struts used between archwork structures in mining or tunnelling.

In our co-pending application No.8711314 filed on the 18th Hay lid87, we have described an improved form of strut for use between archwork structures comprising an extendable strut member having first and second elements in telescopic engagement, first means for securing one element to the other at given relative positions, and second means secured at opposite ends of said first and said second elements to lock the said ends of the elements of adjacent struts securely at either side of a roof girder in an archwork structure.

In the embodiment described in application 8711314, the said second means comprises a U-shaped element secured at its upper free ends to the corresponding edge portions of said first and second elements and is dimensioned to receive a bolt member passing beneath the roof girder, the ends of the adjacent strut elements being located on the girder flange. This embodiment can be used without the need to modify the archwork structure.

In another embodiment, described in application No.8714294 filed 18th June 1987, which does require some modification of the structure, the second means may comprise a plate member secured to the respective ends of the strut and containing an aperture that can be aligned with a corresponding aperture formed in the web of an archwork girder and through which securing means, such as a bolt, can be passed to secure the end of the strut to the structure.

A single securing means may be used to secure the ends of adjacent struts to either sides of the web, by aligning apertures of the respective plate members with the apertures formed in the web.

In a further embodiment of the invention, the second means may be movably secured to opposite ends of the strut through a ball and socket connection, the shank of the ball or the socket being secured, such as by welding, to the said second means with the other shank of the ball or the socket being secured to an end of a strut.

Accordingly1 therefore, the present invention comprises first and second elongate members in telescopic engagement; first means for releasably securing said members to each other to prevent relative movement therebetween and to provide a strut of predetermined length; second means located at opposite end portions of said first and second members whereby the ends of the members may be releasably locked against the side and/or flange of a respective girder, wherein the said second means comprises a first element for securing to a respective girder and a second element secured to a respecti 'e end of an elongate member, one of said first or second elements including a socket member and the other element including a ball member cooperating with said socket member whereby the said first and second means are articulably connected.

The said first element of said second means may include a plate portion containing an aperture to be aligned with a corresponding aperture formed in the web of an archwork girder and through which further securing means, such as a bolt, can be passed to secure the said means to the structure. In an alternative arrangement, the said first element of said second means may include a member having a portion extending over an archwork girder flange and in contact with the said girder web, and a second portion comprising an element depending therefrom and containing an aperture dimensioned to receive third means, e.g. a bolt member, passing beneath the roof girder to a similar element located on the corresponding member of a second strut assembly positioned on the opposite side of the girder web whereby the first portion of both members may be firmly retained against the said girder web.The second portion may conveniently be a U-shaped element, or it may comprise an element containing an aperture to receive the bolt.

Two embodiments of the invention will now, therefore, be described with reference to the following drawings in which: Fig. 1 is a representation of a third embodiment of the invention, Fig. 2 is a representation of a cross section through A-A of Fig.l, Fig. 3 is a representation of a cross-section through B-B of Fig.l, Fig. 4 is a representation of a fourth embodiment of the invention, Fig. 5 is a representation of a cross section through X-X of Fig. 4, Fig. 6 is a representation of a cross sect ion through Y-Y of Fig. 5.

Referring to Figs. 1, 2 and 3 of the drawings1 a strut generally indicated at 1 comprises two U-shaped elements 2 and 3, element 3 having a wider section to enable element 2 to be received therein in sliding engagement. The elements are locked together in the fully extended position by the action of two conventional U-bolts 4 and 5 and clamping bars 34 and 5. The U-bolts are tack welded to element 3 in a spaced apart arrangement, and the clamping bars may be plain, serrated or have protrusions to assist clamping.

A third such bolt and clamp, shown in phantom outline, may be provided if required. A stop member 6 extends downwardly and outwardly from one end 10 of element 2 to engage with clamping bar 34 of U-bolt 4 to define the maximum extended position of elements 2 and 3.

The ends 12 of element 2 and 20 of element 3 are locked against the web of an archwork girder via ball 65, 65' and socket 62, 62' arrangements, in which the shank 6F,' of the ball 65' is secured by welding in the end 12 of element 2 and in the end 20 of element 3, shank 66 of ball 65 is secured in insert 67 which is itself welded into end 20 and has the same crosssectional dimensions as end 12 of element 2. Ball 65 is engaged w-ithin a socket 62 that is welded to a vertical plate 60 containing an aperture 61 to enable the plate to be clamped firmly against the web of an archwork girder via a suitable nut and bolt, the bolt passing through aperture 61 and a corresponding aperture in the archwork girder web. A corresponding plate 60' containing a socket 62' for ball 65' and an aperture 61' is located at the end 12 of element 2.

Referring to Figs. 4, 5 and 6 of the drawings, a strut, generally indicated at 1, comprises elements 2 and 3 in telescopic engagement as described with reference to Fig.l above. The ends 12 of element 2 and 20 of element 3 are located against the girder of an archwork structure via a ball and socket arrangement, in which the shank 66' of the ball 65' is welded into end 12 of element 2 and shank 66 of ball 65 is welded into the insert 67 which in turn is welded into end 20 of element 3, as described with reference to Figure 1. End members 70 consists of a first portion 71 containing a socket portion 75 in which ball 65 is retained, and a second portion 76 that is welded to the base of the portion 71 and contains an aperture through which a bolt may be passed.End 72 of member 70 includes a chamfered portion 73 for co-operation with flange 9 of a girder of an archwork structure having an upstanding web 7. A corresponding member 70' is positioned at the end of element 2 to receive ball member 65'. In certain constructions portions 71, 71', 76 and 76' of members 70, 70' may be integral, e.g. when member 70, 70' is a casting.

In use, member 70' at the end of element 2 is offered up to the upright portion 7 and flange 8 of a roof guide, and member 70 of element 3 of a second strut is offered up to the roof girder in -the corresponding position on the opposite side of the upright portion 7. A bolt, threaded at both eneds but including a nib 33 welded adjacent one threaded end for engagement with flange 9 of the girder, is positioned to extend through members 76, 76' below flanges 8 and 9 of the roof girder. ss The depth of the depending portion of members 76, 76' is arranged to ensure minimum play between the bolt, the members and the flanges of the girders. Nuts 31 and 32.are then screwed onto the threaded ends of bolt 30 and are tightened down against the outer sides of members 76, 76' to draw the opposed elements against flange 9, and the end 72', 72 of elements 2 and 3, against the roof girder whereby the elements are locked securely thereagainst.

The advantage of the socket and ball arrangement is that it enable roof struts to be positioned between girders that are offset in the X or Y axes and/or are not in parallel relationship to each other

Claims (6)

1. CLAIMS: 1. An extendable strut for spanning between the girders of an archway structure comprising: first and second elongate members in telescopic engagement; first means for releasably securing said members to each other to prevent relative movement therebetween and to provide a strut of predetermined length; second means located at opposite end portions of said first and second members whereby the ends of the members may be releasably locked against the side and/or flange of a respective girder;; wherein the said second means comprises a first element for securing to a respective girder and a second element secured to a respective end of an elongate member, one of said first or second elements including a socket member and the other element including a ball member cooperating with said socket member whereby the said first and second elements are articulably connected.
2. 2. A strut according to claim 1 wherein said first element includes a plate portion containing an aperture to be aligned with a corresponding aperture formed in the web of the said girder through which securing means is passed to secure the said plate to the girder, said socket member or said ball member being rigidly secured to said plate portion.
3. 3. A strut according to claim 1 wherein said first element includes a member having a first portion extending over an archwork girder flange to contact the said girder web and a second portion comprising a third element depending therefrom and containing an aperture dimensioned to receive means for securing said portion to a corresponding portion of a second strut positioned on the opposite side of the said girder.
4. 4. A strut member according to claim 3 wherein the said third element is U-shaped and is positioned and dimensioned to receive a bolt member being said securing means, said bolt member extending outwardly of said third elements positioned on either side of said girder, the end of the respective struts being drawn against said girder web by nut means threadedly engaging a corresponding threaded end portions of said bolt member.
5. 5. A strut member according to any one of the preceding claims wherein said first and second elements have a U-shaped sect ion and said first means comprises a U-bolt clamp member.
6. 6. A strut member according to claim 1 and as substantially herein described with reference to the drawings.