GB2366591A

GB2366591A - Anchor member for engaging track in safety line system

Info

Publication number: GB2366591A
Application number: GB0022154A
Authority: GB
Inventors: Christopher Patrick Noe Cronin; Neil Howard Darracott
Original assignee: Total Fabrications Ltd
Current assignee: Total Fabrications Ltd
Priority date: 2000-09-09
Filing date: 2000-09-09
Publication date: 2002-03-13
Anticipated expiration: 2020-09-09
Also published as: GB0022154D0; GB2366591B

Abstract

The anchor member, for engaging a track 10 which is generally T-shaped in transverse cross-section with an opening 15 extending along between laterally extending side recesses 16, comprises a body 20 adapted to extend through the opening into the track and formations 25,32 that are adapted to extend laterally outwards in opposite directions into the recesses. The formations are movable in their orientation between a first position where they can be passed through the opening and a second position where they extend into the recesses so as to hold the anchor in engagement with the track, with the anchor member also including a locking means 28 to retain the formations in the second position. The formations are preferably spaced-apart T-shaped elements, the stem portions of which extend through the opening in the track and the transverse portions of which engage the recesses when in the second position. One T-shaped element may be movable either angularly about the axis of its stem or lengthwise of the axis of its stem relative to the body of the anchor member, with the T-section being resiliently biased towards the position where it engages the recesses.

Description

2366591 PATENTS ACT 1977 A10155GB-GMD Title: Anchor Member Engageable with

a Track

Description of Invention

This invention relates to an anchor member engageable with a track which may be provided in or in association with an elongate element. The anchor member may engage the track for movement therealong while remaining captive relative thereto.

More particularly an anchor member according to the invention is engageable with a track which is generally T-shaped in transverse crosssection, being defined by a base, side walls upstanding therefrom, and inturned lips extending towards one another from the free ends of the side walls. For captive -.engagement with such a track the anchor member requires to have at least one part or formation which also is generally Tshaped as viewed in crosssection transversely of the track.

The invention has been devised in relation to the engagement of a movable anchor member, for attachment of a safety line, with a track formation which extends lengthwise of a structural truss comprising a number of elongate elements disposed in spaced generally parallel relationship to one another with transversely extending elements therebetween, the structural truss preferably being of polygonal configuration in crosssection with elongate elements at the comers thereof. Such a structural truss in which one or more of its elongate elements has a lengthwise extending track formation is the subject of our UK patent application no. 9930628.4. Such structural trusses may be used, for example, in stage or exhibition construction, where a structure might require to be erected for a relatively short period of time and then dismantled. Personnel working on such structures might require to work at a substantial height above the ground, and the ability of a worker to attach himself to a safety line which 2 in turn is connected to an anchor member movable along a truss ensures safety while minimising any inhibition of the worker's freedom of movement lengthwise of the truss.

Engagement of an anchor member with its track has in many cases hitherto. required the anchor member to be passed lengthwise into the track from an end thereof and similarly the anchor member has only been able to be disengaged from the track at an end thereof. Whilst this provides a high degree of safety in respect of the security with which the anchor member is held captive when it is in, for example, a mid-position along the track, it would in many cases be convenient if the anchor member were to be engageable with and disengageable from the track at such a midposition. At the same tuine as providing this convenient ability, however, there should be a high degree of security against unintentional disengagement from the track.

It is broadly the object of the present invention to provide an improved anchor member for such engagement with a track.

According to the invention, we provide an anchor member for captive engagement with a track, the track being of undercut configuration in crosssection comprising an opening leading into respective laterallyoutwardlyextending recesses at each side; the anchor member comprising a body, means adapted to extend through the opening of the track formation, and formations adapted to extend laterally outwardly generally in opposite directions into said recesses; said formations of the anchor member being movable in respect of their disposition and/or orientation between a first condition wherein they can be passed through said opening into the track and a second condition wherein they extend into said recesses to hold the anchor member in engagement with the track, there being provided locking means for retaining said formations in said second condition.

Preferably said formations engage each said recess at spaced positions along the track.

Said formations of the anchor member may be afforded by spaced generally T-shaped elements which, when the anchor member is engaged with the track, have stem portions which extend through the opening of the track and transverse portions which extend laterally outwardly in opposite directions into said recesses of the track.

One of said T-shaped elements may be movable angularly about the axis of its stem portion relative to the body of the anchor member, whilst another may be movable lengthwise of its stem portion relative to the body of the anchor member.

The body of the anchor member may further comprise a guide portion which extends lengthwise of the body, for disposition within the opening of the track. Such guide portion will be generally in alignment with the stem portions of the T-shaped elements. The above described angular movement of one of the T-shaped elements about the axis of its stem portion enables it to be moved to a position in which its transverse portion is generally in alignment with the guide portion, to pass through the opening of the track, whilst a 90' movement of the T-shaped element about the axis of stem portion causes its transverse portion to extend laterally outwardly of the guide portion to enter the recesses of the track.

However if a guide portion is not provided the anchor member may be guided adequately by the T-shaped elements.

The T-shaped element which is movable lengthwise of its stem portion may be caused by such movement to assume a position in which its transverse portion is clear of the guide portion of the anchor member, so that with the anchor member as a whole extending transversely of the track the transverse portion of the T-shaped element may be passed through the opening into the track, after which movement of the anchor member through 90' or thereabouts causes the transverse portion of the T-shaped element to extend laterally into the recesses of the track. The guide portion of the anchor member can then be 4 moved into the opening to the track, and the T-shaped element returned, by movement lengthwise of its stem portion to the position in which its transverse portion lies in the vicinity of the guide portion of the anchor member, to hold the anchor member captive to the track. Thereafter the T-shaped element which is movable angularly about the axis of its stem portion can be moved so that its transverse portion also extends into the recesses of the track.

The anchor member is then guided for movement lengthwise of the track and held captive to the track by its guide portion and by the two transverse portions of the T-shaped elements. If the anchor member were not to be required to be movable lengthwise of the track, the dimensions and/or configuration of its T-shaped elements and/or guide portion may be such that the anchor member is held stationary relative to the track.

Preferably the T-shaped elements are resiliently biased to the positions they respectively assume when the anchor member is engaged with the track as aforesaid. Suitable springs or other resilient elements may operate on the T-shaped elements in the senses in which they are movable.

Preferably the locking means cooperates with the T-shaped elements to prevent their respective angular and lengthwise movements about their stem portions. The locking means may comprise a locking member which extends from the stem portion of the angularly moveable T-shaped element and is engageable with the stem portion of the axially movable T-shaped element.

The locking member may be provided on an arm extending transversely from an end portion of the stem of the angularly movable T-shaped element, the locking member being spring-biased radially away from the stem portion to be engageable with the stem portion of the axially-movable T-shaped element. It may engage beneath a head provided at the end of the stem portion of the axially movable T-shaped element, to prevent such axial movement thereof.

The invention will now be described by way of example with reference to the accompanying drawings, of which:- Figure I is a perspective view showing an anchor member in accordance with the invention, in a mounting/dismounting condition in relation to an elongate track member; Figure 2 is a perspective view showing the condition of the anchor member when engaged with the track member; Figure 3 is a perspective view illustrating a further possible arrangement of track-engaging formations of the anchor member; Figures 4 and 5 illustrate diagrammatically yet a further possible arrangement of track-engaging formations of the anchor member.

Referring to the drawings, in Figure I there is shown part of an elongate element 10 which may be an extrusion of an aluminium alloy and form part of or be provided in association with a structural truss. It comprises a box section portion indicated generally at I I and a portion which defines a track formation. The latter- portion comprises a recessed base wall 12 (which also constitutes one side of the box section portion 11), side wall portions 13 upstanding from the base 12, and opposed intumed lips 14 extending towards one another from the free ends of the side wall portions B. The track thus defined is generally T-shaped in cross-section, with an opening 15 between the adjacent ends of the lips 14 leading to oppositely outwardly extending recesses 16 behind the lips 14. Also visible on the elongate element 10 are external ribs and the like, but these will not be described in any further detail as they do not form part of the present invention.

An anchor member engageable with the track comprises a body indicated generally at 20. The body, may be in one piece or, as illustrated, may be of laminated construction comprising a number of body parts indicated at 20a, 20b, 20c disposed upon one another and secured together by any convenient means (not shown). Such construction enables the provision of internal cavities in the body for the reception of springs and the like for the purposes described hereafter, and for an anchor ring 21 for connection of a 6 security line to be held captive to the body. The part 20-c of the body 20 includes a guide portion 22 which when the anchor member is engaged with the track lies in the opening 15 between the free ends of the lips 14. The body may be of metal, e.g. aluminiurn alloy, or/and may be of a suitable plastics material.

Movably mounted relative to the body there are two generally T-shaped elements, one adjacent each end of the body. The first of such T-shaped elements comprises a stem 23 which is received in the body for angular movement about its axis 24, and a transverse portion 25 at one end of the stem. The angular movement provides for the transverse portion 25 to be moved between the position in which it is shown in Figure I in which it lies in alignment with the guide portion 22 and the position in which it is shown in Figure 2 in which it extends transversely outwardly relative to the guide portion 22, to lie within the recesses 16 of the track when the anchor member is engaged with the track. Spring biasing means (not shown) preferably biases it to the latter position. Above the body 20 the stem 23 has secured to it a boss 26 from which an arm 27 extends radially outwardly relative to the axis 24. The arm 27 carries a locking member 28 which is spring biased away from the boss 26, the end of the locking member 28 being forked at 29. Beneath the locking member 28 there is a projection, e.g. a pin (not shown), which engages with a groove in the upper surface of the body 20, the groove comprising an arcuate portion 30 concentric with the axis 24 and a straight portion 31 extending therefrom towards the opposite end of the body 20. This means that the locking member 28 is only able to move away from the boss 26 when it is facing the opposite end of the body 20 and the transverse portion 25 extends laterally outwardly relative to the guide portion 22. Conversely the Tshaped element is only able to be moved angularly about the axis 24 after the locking member 28 has been moved towards the boss 26 against the action of its biasing spring.

The other T-shaped element comprises a stem 32 and a transverse portion 33 at one end thereof The other end of the stem 32 has a head 34 secured thereto, and angular movement of the stem and transverse member 33 about the axis 35 of the stem is prevented from taking place for example by the stem being of non-circular cross-sectional shape (e.g. oval as illustrated), by interengaging formations on the stem and body, or otherwise. The T-shaped element is, however, movable lengthwise of the axis of the stem, and is spring biased to the position in which it is shown in Figure 2, with the head 34 spaced from the upper surface of the body 20 of the anchor element and the transverse portion 33 generally in line with the lower surface of the guide portion 22 of the anchor element. The T-shaped element is movable to the position shown in Figure 1, in which the transverse portion 33 is clear of the.guide portion 22, by pressing on the head 34.

To -engage the anchor member with the track at a mid-position of the track, the anchor member is held in the orientation relative to the track in which it is depicted in Figure 1, and the head 34 depressed so that the transverse portion 33 is clear of the guide portion 22. This enables the transverse portion to be passed through the opening 15 of the track, after which the anchor member can be moved bodily through about 90' so that the transverse portion 33 extends outwardly in opposite directions into the recesses 16 of the track. The guide portion 22 of the anchor member can enter the opening 15, and as it does so the transverse portion 33 is returned, under the influence of its spring biasing, to the position in which it is shown in Figure 2.

When the guide portion 22 of the anchor member lies in the opening 15 of the track, the transverse portion 25 of the other T-shaped element is in alignment with the recesses 16 of the track. This T-shaped element can then be moved angularly about the axis 24 of its stem 2' 3 so that the transverse portion enters the recesses 16 of the track, such movement being effected by pressing on the locking member 28 possibly assisted by any spring-biasing 8 means provided in association with this T-shaped element. When the locking member 28 is in the position extending towards the opposite end of the body 20, corresponding to the disposition of the transverse portion 25 substantially perpendicular to the length of the body 20, the pin beneath the locking member 28 is able to enter the straight portion 31 of the groove in the upper surface of the body 20 and the locking member 28 move under the action of its biasing spring away from the boss 26 so that its forked end 29 embraces the stem 32 beneath the head 34. When this position has been assumed, it will be appreciated that the cooperation of the locking member 28 with the stem 34 of the other T- shaped element requires a sequence of operations which is the reverse of the above described sequence to be performed before the anchor member can be disengaged from the track. Such a sequence is most unlikely to be carried out unintentionally.

Referring now to Figure 3 of the drawings, this illustrates diagrammatically another way in which track-engaging formations of an anchor member can be arranged. Figure 3) shows a first element 50 having upstanding portions 51 with track-en aging formations 52 thereon. A further element 53 g 1, has upstanding wall portions 54 with track engaging formations 55 thereon.

They are shown in full lines in Figure 3) in a position assumed when they are engaged with a track, with the upstanding wall portions 51, 54 in back to back relationship to extend through the opening of a track as previously described, and the formations 52, 55 extending away from one another to enter the recesses beyond the opening of the track.

The elements 50, 53 are supported by a body of an anchor member in such a way that they are able to move longitudinally of the track relative to one another and also transversely of the track so that they are able to assume an alternative relative position in which the element 50 and its associated parts is shown in broken lines in Figure '). In this relative position the formations 52, are in alignment with one another in the longitudinal direction so that they 9 can pass through the opening of the track. Then return of the elements 53, 50 to the relative position first described causes the formations 52, 55 to engage the track in such a way that they cannot be removed therefrom. In the drawing, end faces of the formations 52, 55 and the associated upstanding walls 51, 54 are shown as inclined cam surfaces which may cooperate in the course of such relative movement of the elements. An y suitable locking means operative between the elements 50, 53 and the body of the anchor member will be provided for ensuring that the condition of secure engagement of the track is retained until disengagement from the track is required.

Referring now the Figures 4 and 5 of the drawings, these show yet another embodiment which includes a body 60 above which is shown a support member 61. The support member 61 caiTies, for pivotal movement about a spindle 62, two spaced track-engaging elements 63 with respective engaging fori-nationg-.64. The member 61 further carries, for pivotal movement about a spindle (not shown) but whose axis is indicated at 65 parallel to the spindle 62, two spaced track-engaging elements 66 with engaging formation 67. The formations 67 face in the opposite direction to the formations 64, transversely of a track part of which is indicated at 68. All the elements 63, 66 are pivotably engaged with a further spindle 69 which extends parallel to the aforementioned spindles and is carried by a portion 70 upstanding from the body 60. The result of such engagement is that a movement of the body 60 away from the member 61 to the position illustrated in Figure 5 effects a pivotal movement of the elements 63), 66 to a retracted position shown in Figure 5 in which their formations 64, 67 are able to pass through the opening of the track 68. It will of course be appreciated that some lost motion has to be provided in the connection between the elements 63, 66, 70 and the spindle 69 to accommodate the respective different arcuate paths of movement of the pails of the elements which cooperate with the spindle.

When in the condition shown in Figure 4 the formations 64, 67 extend into the recesses of the track 68 to retain the anchor member to the track and guide it for movement there along. Guide formations are shown at 71 on the member 61, for cooperation with the boundaries of the opening of the track. Suitable locking means operative between the body 60 and member 61 would be provided for holding them in the position shown in Figure 4, release of such locking means enabling them to be moved to a position shown in Figure 5 for engagement with the track or release therefrom as may be required.

In the present specification "comprise" means "includes or consists of' and "comprising" means "Including or consisting of'.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof

Claims

1. An anchor member for captive engagement with a track, the track being of undercut configuration in cross-section comprising an opening leading into respective laterally-outwardly-extending recesses at each side; the anchor member comprising a body, means adapted to extend through the opening of the track formation, and formations adapted to extend laterally outwardly generally in opposite directions into said recesses; said formations of the anchor member being movable in respect of their disposition and/or orientation between a first condition wherein they can be passed through said opening into the track and a second condition wherein they extend into said recesses to hold the anchor member in engagement with the track, there being provided locking means for retaining said formations in said second condition.

2. An anchor member according to Claim I wherein said formations engage each said recess at spaced positions along the track.

3. An anchor member according to Claim 2 wherein said formations are afforded by spaced generally T-shaped elements having stem portions which, when the anchor member is engaged with the track, extend through the opening into the track and transverse portions which extend laterally outwardly in opposite directions into said recesses of the track.

4. An anchor member according to Claim 3 wherein one of said T-shaped elements is movable angularly about the axis of its stem portion relative to the body of the anchor member.

5. An anchor member according to Claim 3 or Claim 4 wherein one of said Tshaped elements is movable lengthwise of the axis of its stem portion relative to the body of the anchor member.-

6. An anchor member according to any one of Claims 3 to 5 wherein the body comprises a guide portion extending lengthwise of the body, for disposition in the opening of the track.

7. An anchor member according to Claim 6 as appendant to Claim 4 wherein said angular movement of the T-shaped element causes its transverse portion to be moved between positions in which it is generally in alignment with the guide portion and in which it extends laterally outwardly of the guide portion.

8. An anchor member according to Claim 6 or Claim 7 as appendant to Claim 5 wherein said T-shaped element movable lengthwise of the axis of its stem portion is movable to a position in which its transverse portion is clear of the guide portion of the anchor member.

9. An anchor member according to any one of Claims 3 to 8 wherein said Tshaped elements are resiliently biased to positions they assume when the anchor member is engaged with the track.

10. An anchor member according to any one of Claims 4 to 9 wherein said locking means cooperates with the T-shaped elements to prevent their respective movements about the axes of their stem portion.

11. An anchor member according to Claim 10 wherein the locking means comprises a locking member which extends from the stem portion of the 13 angularly movable T-shaped element and it is engageable with the stem portion of the axially movable T-shaped element.

12. An anchor member according to Claim I I wherein the locking member is spring biased into said engagement.

13. An anchor member substantially as hereinbefore described with reference to the accompanying drawings.

14. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.