GB2172794A - Overhead track support systems - Google Patents

Abstract

Elongate track members (1) are of uniform cross-section and comprise a lower open-ended hollow section (2) having a lower central open slot (3) extending lengthwise between opposite ends, and at an upper side a central upwardly extending upright flange (4) extending lengthwise from end-to-end and having a T-head transverse flange (5). Splice plates (10) are of short length relative to the track members (1), and each comprise a lower channel section and an upper upright web (11) adapted to fit in close fitting relation about the track members (1) with the upright web (11) abutting the flange (4) and engaging between the T-head (5) and an upper side of the hollow-section (2). The channel section closely fits about the hollow section (2) with a lower flange terminating short of the slot (3). Track members (1) are secured in end-to-end relation by splice plates (10) overlapping the joint and disposed at opposite sides, the assembly being secured by bolts passing through the flanges (4, 11) of the members (1) and the plates (10). Threaded bores (18) are provided at intervals along the channel section of the splice plates whereby grub screws or the like may be employed to ensure playfree location of the plates relative to the members and precise alignment of the members. <IMAGE>

Description

SPECIFICATION Overhead track support systems This invention relates to an overhead support system and is particularly, but not exclusively, concerned with such a system for use in theatres to provide an overhead suspension track for curtains or other suspended apparatus or people.

In known track systems for these purposes, there are provided open-ended elongate track members of box-like section having an elongate slot extending along a lower side and formed of folded sheet metal e.g. steel to provide a rigid elongate support member within which pulley support means may run with a suspension support depending therefrom through the slot. Means to connect track members in alignment comprise splice plates adapted in pairs to form splice and support members. Each splice plate comprises an upper flange formed with a lower portion of half box-form such that when the upper flange portions of a pair are abutted the half-box portions may embrace the box-like section, lower facing edges of the half-box portions being spaced apart sufficiently to avoid obstructing the slot of the track member.

The splice members are assembled by bolts passing through the abutting flange portions, and the sides of the half-box portions are provided with ap array of threaded apertures into which bolts are screwed for engaging the external surfaces of a track member to secure it therein. The splice plates are formed from folded sheet metal e.g. steel and the half-box portions provide a large clearance fit around the track member box-section, the bolts in the threaded apertures serving to take up the clearance and to centre the track member such that two track members may be substantially precisely aligned within the splice. This is time consuming and requires skill and care to avoid obstruction in use due to slight misalignment of the track members.The large number of bolts required presents difficulties in assembly, storage and transport of a support system comprising a multiplicity of track members and splices and also present external projections in assembled use which may present hazards to lines, ropes, chains or the like used with the system for supporting and traversing purposes.

It is an object to provide an improved overhead support system.

An overhead track system according to the present invention comprises a plurality of elongate track members of uniform cross-section and a plurality of splice plates of configured uniform section adapted to fit closely about an outer profile of the track member.

Each track member comprises an open-ended box-section having at a lower side a central slot extending lengthwise and from end-to-end of the member, and at an upper side a central upwardly extending upright flange also extending lengthwise of the member and from end-to-end thereof.

The upright flange is suitably formed with a Tform head ortransverseflange.

Opposed edges of the box section at opposite sides of the slot are suitably turned up at an inclination.

Inner corners of the box section are suitably radiused and the member is suitably an extrusion for example aluminium or an alloy thereof.

The box section is suitably square and formed with flat outer surfaces and may-be formed as ani' extrusion.

Each splice plate comprises a profiled member of short length relative to a track member and of uniform cross-section throughout its length, the cross-section comprising a lower channel section having an upright web and transverse flanges of which the upper is formed with an upwardly extending flange parallel to and extending away from the web outwardly of the channel. The lower transverse flange extends from the web a lesser distance than the upper flange and is suitably chamfered upwardly at its free edge.

Respective trapezoidal thickening ribs extend externally of the channel along the upper flange adjacent the web and along the web and are provided with threaded bores at spaced intervals for grub or allen screws.

The upwardly extending flange is dimensioned to fit closely within the space between the T-form flange of the track member and an upper surface of the box-like portion thereof and the profile of a splicatember is such that with the upwardly extending flange so fitted in abutment with the upright flange of the track member the channel section embraces the box-like portion in close fitting relation with the free edge of the lower flange thereof terminating short of the track member slot.

The upwardly extending flanges of the splice plate and of a track member are suitably provided with complementary bores for the receipt of securing bolts.

The invention includes a kit of parts for a splice assembly as described and an overhead system assembled from a plurality of track n ers and splice plates of the form described.

The invention will now be described, by way of example, with reference to the accompanying partly diagrammatic drawings, in which: Figure lisa fragmentary perspective view of an end of a track section according to the invention; Figure 2 is a perspective.view of a splice plate according to the invention; Figure 3 is a fragmentary perspective view of a pair of track members in alignment with a splice plate in position; Figure 4 is an end view of a splice assembly; Figure 5 is an end view of the track member of Figure 1; Figure 6 is an end view of the splice plate of Figure 2; and Figure 7 is a fragmentary side elevation of the splice assembly of Figure 3.

Referring now to Figures 1 and 5, a track member 1 which may be of any predetermined length comprises an open-ended lower box-section 2 of generally square form and having a longitudinal central slot 3 formed in its lower side and extending from end-to-end of the member 1. An upright flange 4 extends centrally of the upper side of section 2 from end-to-end of member 1 and is formed with an upper transverse flange 5 in T-shape manner. The member is of unitary nature being integrally formed for example as an aluminium extrusion. Opposed edges 6 of box-like section 2 at opposite sides of slot 3 are turned up at an inclination and inner corner 7 of the box 2 are suitably radiused.

The flanges 4,5 may be formed in any desired manner with holes, not shown, for mounting purposes.

Referring now to Figures 2 and 6 the splice plate 10 comprises an elongate but relatively short member of uniform cross-section and adapted to fit about a side of the track member of Figure 1 as shown in Figures 3,4 and 7. The member 10 comprises an upperflange 11 from which depends a channel-shaped section 12 arranged with its web 13 parallel to the flange 11 and with flanges 14 normal thereto, the flange 11 extending upwardly from an end of the upper channel flange 14. Inner surfaces of the channel section 12 are adapted to fit closely about outer faces of the track box section 2 as shown in Figures 3 and 4 with the lower flanges 14 terminating short of the slot 3. The edges 15 of the lower flange 14 is chamfered to provide a smooth merging with the inclined edge portions 6.A trapezoidal section rib 16 extends along an outer upper edge of the channel section of the plate 10 and a similar rib 17 extends along an outer surface of the web 13 and a level slightly below a median line. The ribs 16 and 17 are formed at spaced intervals with threaded bores 18 for grub-screws e.g. allen key screws not shown. The bores 18 are suitably countersunk so that the screws do not extend externally of the flange plate 10 in use.

The splice plate is of unitary form and is suitably integrally formed by extrusion for example from aluminium.

The flange 11 is of height such as to fit closely between the upper flange 5 and an upper surface of the box section 2 of a track member 1 as seen in Figures 3,4 and 7 and is formed with spaced holes 19 so that when a pair of splice plates 10 are assembled at opposite sides of a pair of track members 1 arranged in end-to-end alignment bolts may be passed through the holes 19 and corresponding holes formed in the flanges 4 of the member 1 to secure the member 1 in end-to-end alignment. The grub or allen screws in the bores 18 serve to dlamp the end portions of the track member in position by engaging outer side and top surfaces of the box section 2 thereof.

It will be understood that the box sections 2 and the slots 3 provide passage for traversing devices and suspension means in known manner.

The track system of the invention provides for close play-free fit between the splice plates 10 and the track members 1 so that a play-free alignment of end-to-end members 1 is obtained with facility. The external profile of the box-like sections formed by the pair of splice plates 11 in a splice assembly presents minimal obstruction to traversing member ropes and the like and is also convenient for storage and transport when disassembled. As a result of the section form of the track member 1 and splice plates 11 a rigid assembly is obtained with facility and track alignment problems are largely obviated.

Claims (16)

1. An overhead track support system comprising a plurality of elongate track members of uniform cross-section and a plurality of splice plates of configured uniform cross-section and adapted to fit closely about an outer profile of a track member, each track member comprising an open ended hollow section having at a lower side a central open slot extending lengthwise and from end-to-end of the member, and at an upper side a central upwardly extending upright flange extending lengthwise and from end-to-end of the member, each splice plate comprising a profiled member of short length relative to a track member and comprising a lower channel section formed at an upper flange edge with an upright upwardly extending web, each splice plate being adapted to fit in close relationship about a track member with the upright web abutting the upright flange of the track member and channel section closely fitting about the hollow section of the track member, a lower flange of the channel section terminating short of the slot, whereby a pair of track members may be secured in end-to-end relationship by disposing a pair of splice plates in overlapping relationship with respect to abutted ends of the track member and at opposite sides thereof and securing the splice plates to the members through the upright webs of the splice plates and the upright webs of the track members.

2. A track member in or for track systems as claimed in claim 1, in which the hollow section is a box section of rectangular cross-section.

3. Atrack member as claimed in claim 2, in which opposed edges of the box section at opposite sides of the slot are turned up at an inclination.

4. Atrack member as claimed in claim 2 or 3, in which inner corners of the box section are radiussed.

5. A track member as claimed in any of claims 2 to 4, in which the box section is formed with flat outer surfaces.

6. A track member as claimed in any of claims 2 to 5, in which the track members are metal extrusions.

7. A track member as claimed in claim 6, in which the metal is aluminium or an aluminium alloy.

8. A track or track member as claimed in any preceding claim in which the upright flange is formed with an upper transverse flange in the manner of a T-head.

9. A splice plate in or for a track system as claimed in claim 1, comprising a profiled member of short length relative to a track member and of uniform cross-section throughout its length, the crosssection comprising a lower channel section having an upright web and transverse flanges of which the upper is formed at an end distal from the web with an upwardly extending flange parallel to and extending away from the web outwardly of the channel.

10. Splice plate as claimed in claim 9, in which the lower flange of the channel extends from the web a lesser distance than the upper flange.

11. A splice as claimed in claim 9 or 10, in which the lower flange is chamfered upwardly at its free edge.

12. A splice plate as claimed in any of claims 9 to 11, in which external thickening ribs extend longitudinally and externally of the channel along the upper flange thereof adjacent the web, and along the web and threaded bores extend through the plate at intervals along the thickening ribs.

13. A splice plate as claimed in claim 12, in which the ribs are chamfered at opposite sides to present generally trapezoidal rib sections thickening towards their bases.

14. A splice plate as claimed in any of claims 9 to 13, in which the upwardly extending flange is formed with a pair of bores spaced apart longitudinally of the plate.

15. A track system as claimed in claim 1 and comprising a plurality of track members as claimed in claim 8 and a splice plate as claimed in claim 9, in which the upwardly extending flange of the splice plate is adapted to fit closely within the space between the Tform transverse flange of a track member and an upper external surface portion of the hollow section with said splice-plate flange abutting the upright flange of the track member and the channel section embracing the hollow section in close fitting relation with the free edge at a lower side of the channel section terminating short of the track member slot.

16. A track system substantially as hereinbefore described with reference to the accompanying drawings.