GB2233359A

GB2233359A - Access flooring

Info

Publication number: GB2233359A
Application number: GB9009324A
Authority: GB
Inventors: Alfred Philip Burns
Original assignee: Dorman Smith Holdings Ltd
Current assignee: Dorman Smith Holdings Ltd
Priority date: 1989-04-27
Filing date: 1990-04-26
Publication date: 1991-01-09
Also published as: GB9009324D0

Abstract

An underfloor cable trunking system comprises open topped cable trunking 10 and, closing the open top of the trunking, a multiplicity of substantially flat cover plates 15 arranged in alignment along the trunking with their neighbouring side edges in abutment one with another. Some or all of the abutting side edges are provided with at least one indented portion 25 such that, in cooperation with a similar indented portion on a corresponding abutting side edge, two adjacent side edges define therebetween one or more apertures in which may be received one or more fixing elements. Directly or indirectly supported on the trunking is a load bearing structure including a plurality of transversely extending beams 13, some or all of the beams being provided with one or more fixing holes. The arrangement is such that marginal portions of adjacent cover plates overlie the transversely extending beams and are releasably secured thereto by means of fixing elements received within the apertures defined between adjacent side edges and within the fixing holes in the transversely extending beams. <IMAGE>

Description

UNDERFLOOR CABLE TRUNKING This invention relates to underfloor cable trunking systems of the kind comprising underfloor trunking for housing electric power, telephone and other service cables and, at predetermined positions in the system, boxes which house and provide access to socket outlets associated with the power, telephone and other service cables, such boxes generally and hereinafter being referred to as "access" boxes.

There are generally two kinds of flush underfloor cable trunking systems. One is used with a "false" floor, supported on jacks or other upstanding supports so that there is a void beneath the floor. The other type of system is used with solid floors in which a "ribbon screed" is laid so as to support the cable trunking. The present invention attempts to provide an underfloor cable trunking system which is suitable for use with either 'false' or solid floors.

Accordingly there is provided an underfloor cable trunking system comprising open topped cable trunking and, closing the open top of the trunking, a multiplicity of substantially flat cover plates arranged in alignment along the trunking with their neighbouring side edges in abutment one with another, some or all of the abutting side edges being provided with at least one indented portion such that, in cooperation with a similar indented portion on a corresponding abutting side edge, two adjacent side edges define therebetween one or more apertures in which may be received one or more fixing elements; and, directly or indirectly supported on the trunking, a load bearing structure including a plurality of transversely extending beams, some or all of the beams being provided with one or more fixing holes; the arrangement being such that marginal portions of adjacent cover plates overlie the transversely extending beams and are releasably secured thereto by means of fixing elements received within the apertures defined between adjacent side edges and within the fixing holes in the transversely extending beams.

The indented portions of the cover plates combine to form the apertures in which the fixing elements are received. This has the advantage that one transversely extending beam can support two adjacent cover plates. An additional advantage is that the number of fixing elements to be operated when several cover plates are to be inserted or removed is considerably reduced. The invention can therefore be considered to be an improvement to applicant's earlier UK patent number 2175963B in which each cover plate is fixed separately at its four corners to separate supporting structures.

Preferably each of the abutting side edges of the cover plates is provided with two indented portions. Each indented portion is preferably semicircular in shape, so as to define a circular aperture with the indented portion of an adjacent side edge.

Preferably the one or more fixing elements each include a head and a threaded shank. Preferably a washer is provided on some or all of the fixing elements adjacent the head thereof. Where the fixing element is applied with a rotary movement, there may be a tendency for the two adjacent cover plates defining the aperture for the fixing element to be pushed apart. The provision of a washer helps to prevent such rotary movement from being transferred to the cover plates and hence decreases the tendency for the cover plates to be pushed apart.

Preferably each of the cover plates is recessed in the area of the or each indented portion so as to receive the head of one of the fixing elements, such that the head of the fixing element does not protrude beyond the surface of the cover plate. In one preferred arrangement the area of the or each indented portion is depressed so as to extend below the plane of each flat cover plate. The head of one of the fixing elements can then be received in the depressed area.

In this arrangement, the one or more fixing holes are preferably each located in a concave area of the transverse beam, each concave area being adapted to receive a depressed area of one of the cover plates.

Where a washer is present, it is preferably provided with a recess in which the head of one of the fixing elements is received, and the one or more recesses in each of the cover plates are such as to receive both the head of one of the fixing elements and the washer, such that neither the head of the fixing element nor the washer protrude beyond the surface of the cover plate. In a similar manner to the cover plates, the washer is conveniently provided with a depressed area extending below the general plane of the washer so as to define the recess in which the head of one of the fixing elements is received.

Preferably the one or more fixing elements comprise threaded screws, and the fixing holes in the transverse beams are tapped so as to receive the screws. Alternatively the one or more fixing elements comprise threaded bolts, the fixing holes in the transverse beams being clearance holes, and there is provided a nut on each bolt which may be tightened to secure the bolt and a transverse beam one against the other.

The load bearing structure may comprise a plurality of longitudinally extending supports, the supports interlinking the transversely extending beams and being releasably secured thereto.

At one or more positions a cover plate and the longitudinally extending supports therebelow may be omitted and replaced by an access box including a body portion and a frame, the body portion being of a size such that it is received between adjacent transversely extending beams, and the frame including one or more indented portions adapted to cooperate with the side edges of adjacent cover plates to define one or more apertures in which fixing elements may be received. Thus any one of the cover plates may be removed and an access box may take its place, the frame being secured to the transverse beams in a similar fashion to the cover plates.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of the trunking of the underfloor cable trunking assembly; Figs. 2 to 4 are respectively a perspective view, a side elevation and a fragmentary plan view of a transverse support beam; Fig. 5 is a perspective view of an assembly of cover plates; Fig. 6 is a fragmentary sectional view through the junction of two cover plates and a transverse support beam showing the securement thereof; and Fig. 7 is a fragmentary plan view of an access box cover plate and neighbouring cover plates.

Referring to Fig. 1 of the drawings, the underfloor cable trunking system comprises open-topped cable trunking 10 of substantially transversely elongate U-configuration whereof the upstanding limbs 11 are, at their free ends, inwardly and downwardly turned as indicated at 12. Mounted within the trunking 10 at equidistantly spaced locations are transverse support beams 13, each of which, at each end, has open-topped hook configurations 14 for location under the ends 12 of the trunking limbs 11.

The transverse beams 13 form part of a load bearing structure, whereof the other part is longitudinally-extending supports (not shown) which interconnect adjacent transverse beams 13 and serve to support with the latter a multiplicity of substantially flat rectangular cover plates 15 which serve to close the open top of the trunking 10 at floor level, the cover plates 15 and transverse beams 13 being bolted or screwed together. The cover plates 15 are disposed in edgeto-edge abutting relationship flush with a floor (not shown) of premises in which the trunking system is laid.

At predetermined locations a cover plate 15 is replaced by a cover plate 16 of an access box (not shown).

The trunking system is, in this instance, supported on beams 17 which are, in turn, adjustably supported by jacks 18, disposed in a void beneath the premises' floor.

Each transverse beam 13 is of inverted U-shape with the free ends of its limbs 19 turned out to define support flanges 20 through which the beam 13 is connected to the floor of the trunking 10 by any convenient means.

Each transverse beam 13 has a top surface 21 on which abutting edges of adjacent cover plates 15 rest and which, at each end adjacent to the hook configurations 14, has a depressed region 22.

Within each depressed region 22 there is provided a circular downwardly-extending frusto-conical shaped recess 23 terminating in a screw or bolt-receiving hole 24.

Each cover plate 15 at its opposed transverse edge is formed, adjacent each corner, with a semi-circular, downwardly-extending indentation 25 adapted to be aligned, in use, with a corresponding indentation 25 in a neighbouring cover plate 15.

The abutting longitudinal edges of two adjacent cover plates 15 thus define two circular downwardly-extending frusto-conical shaped apertured recesses 25,25 which are positioned to be in nesting alignment with the holed recesses 23,24 of the transverse beam 13 on which the longitudinal edges rest.

The securement of the adjacent cover plates 15 together and to the supporting transverse beam 13 is effected by washers 27 and screws or bolts 28.

Each washer 27 is of concave construction with a flat peripheral flange 29, and each screw or bolt 28 consists of a shank 30 and a frusto-conical shaped head 31.

Securement is effected by locating a washer 27,29 within an apertured recess 25,25 defined by adjacent cover plates 15 and inserting the screw or bolt shank 30 therethrough and through the hole 24 to screw or bolt the cover plates 15 and transverse beam 13 together with or without the use of nuts (not shown).

Due to its shape, the head 31 of the screw or bolt 28 it is accommodated within the recess 25,25 and does not protrude above the level of the cover plates 15.

At predetermined locations of the trunking system a cover plate 15 is omitted together with the underlying longitudinally-extending supports of the load bearing structure and an access box is fitted between the adjacent transverse beams 13. The access box has, as aforesaid, a cover plate 16 defined by a rectangular frame 32 configured at its opposed longitudinal edges like the cover plates 15 for securement to adjacent abutting cover plates 15 in the manner described above. The rectangular frame 32 surrounds an access door 33 hinged at one longitudinal edge for upward opening to permit access to sockets, outlets, etc. (not shown) within the trunking 10.

In an alternative arrangement the cover plates 15 are indented without depression and the support beams have non-depressed wholly level top surfaces with a bolt or screw receiving hole adjacent each end. In this instance, the washer is of flat configuration and the head of the bolt or screw is also flat.

The cover plate/transverse beam assembly and securing means disclosed herein is disclosed and claimed in our copending Patent Application No. of even date.

Claims

1. An underfloor cable trunking system comprising open topped cable trunking and, closing the open top of the trunking, a multiplicity of substantially flat cover plates arranged in alignment along the trunking with their neighbouring side edges in abutment one with another, some or all of the abutting side edges being provided with at least one indented portion such that, in cooperation with a similar indented portion on a corresponding abutting side edge, two adjacent side edges define therebetween one or more apertures in which may be received one or more fixing elements; and, directly or indirectly supported on the trunking, a load bearing structure including a plurality of transversely extending beams, some or all of the beams being provided with one or more fixing holes; the arrangement being such that marginal portions of adjacent cover plates overlie the transversely extending beams and are releasably secured thereto by means of fixing elements received within the apertures defined between adjacent side edges and within the fixing holes in the transversely extending beams.

2. A trunking system according to claim 1 wherein each of the abutting side edges is provided with two indented portions.

3. A trunking system according to claim 1 or claim 2 wherein each indented portion is semicircular in shape, so as to define a circular aperture with the indented portion of an adjacent side edge.

4. A trunking system according to any of claims 1 to 3 wherein the one or more fixing elements each include a head and a threaded shank.

5. A trunking system according to claim 4 wherein a washer is provided on some or all of the fixing elements adjacent the head thereof.

6. A trunking system according to claim 4 or claim 5 wherein each of the cover plates is recessed in the area of the or each indented portion so as to receive the head of one of the fixing elements, such that the head of the fixing element does not protrude beyond the surface of the cover plate.

7. A trunking system according to claim 6 wherein the area of the or each indented portion is depressed so as to extend below the plane of each flat cover plate.

8. A trunking system according to claim 7 wherein the one or more fixing holes are each located in a concave area of the transverse beams, each concave area being adapted to receive a depressed area of one of the cover plates.

9. A trunking system according to any of claims 6 to 8 when appendant to claim 5 wherein the washer is provided with a recess in which the head of one of the fixing elements is received; and the one or more recesses in each of the cover plates are such as to receive both the head of one of the fixing elements and the washer, such that neither the head of the fixing element nor the washer protrudes beyond the surface of the cover plate.

10. A trunking system according to claim 9 wherein the washer is provided with a depressed area extending below the general plane of the washer so as to define the recess in which the head of one of the fixing elements is received.

11. A trunking system according to any of claims 4 to 10 wherein the one or more fixing elements comprise threaded screws, and the fixing holes in the transverse beams are tapped so as to receive the screws.

12. A trunking system according to any of claims 4 to 10 wherein the one or more fixing elements comprise threaded bolts, the fixing holes in the transverse beams are clearance holes, and there is provided a nut on each bolt which may be tightened to secure the bolt and transverse beam one against the other.

13. A trunking system according to any of claims 1 to 12 wherein the load bearing structure includes a plurality of longitudinally extending supports, the supports interlinking the transversely extending beams and being releasably secured thereto.

14. A trunking system according to claim 13 wherein at one or more positions a cover plate and the longitudinally extending supports therebelow are omitted and replaced by an access box including a body portion and a frame, the body portion being of a size such that it is received between adjacent transversely extending beams, and the frame including one or more indented portions adapted to cooperate with the side edges of adjacent cover plates to define one or more apertures in which fixing elements may be received.

15. A trunking system substantially as hereinbefore described with reference to the accompanying drawings.

16. Securing means for securing first and second members one to another, whereof the first member includes a substantially planar region having a recessed aperture therein while the second member has an aperture corresponding to the recessed aperture of the first member, the securing means comprising a fixing element including a head and a threaded shank, the shank being adapted to pass through the recessed aperture in the substantially planar region of the first member and to be received in the corresponding aperture in the second member; and a washer adapted to be located on the fixing element adjacent the head thereof, and being provided with a recess for receiving the head of the fixing element, and the arrangement being such that, in use, the head of the fixing element and the washer are received in the recess of the first member so that neither the head of the fixing element nor the washer protrudes beyond the surface of the substantially planar region of the first member.

17. Securing means according to claim 16 wherein the washer is provided with a depressed portion which extends below the general plane of the washer, the head of the fixing element being adapted to be received in the depressed portion.

18. Securing means according to claim 16 or 17 wherein the fixing element comprises a threaded screw adapted to be received in a tapped aperture in the second member.

19. Securing means according to claim 16 or 17 wherein the fixing element comprises a threaded bolt provided with a complementary nut, the threaded bolt, in use, being adapted to be received in a clearance hole in the second member and to co-operate with the nut to secure the first and second members one against the other.

20. Securing means substantially as hereinbefore described with reference to the accompanying drawings.

21. A structural assembly comprising first and second members, the first member including a substantially planar region; a fixing element including a head and a threaded shank, the shank passing through an aperture in the substantially planar region of the first member and being received in a corresponding aperture in the second member; and a washer located on the fixing element adjacent the head thereof, the arrangement being such that the washer is provided with a recess in which the head of the fixing element is received, and the first member is also recessed in the area of the aperture so as to receive the head of the fixing element and the washer, such that neither the head of the fixing element nor the washer protrudes beyond the surface of the substantially planar region of the first member.

22. A structural assembly according to claim 21 wherein the washer is provided with a depressed portion which extends below the general plane of the washer, the head of the fixing element being received in the depressed portion.

23. A structural assembly according to claim 21 or claim 22 wherein the first member is provided, in the area of the aperture, with a depressed portion which extends below the plane of the substantially planar region, the washer and the head of the fixing element being received in the depressed portion.

24. A structural assembly according to claim 23 wherein the corresponding aperture in the second member is located in a concave region adapted to receive at least a part of the depressed portion of the first member.

25. A structural assembly according to any of claims 21 to 24 wherein the fixing element comprises a threaded screw and the corresponding aperture in the second member is tapped to receive the screw.

26. A structural assembly according to any of claims 21 to 24 wherein the fixing element comprises a threaded bolt, the corresponding aperture in the second member is a clearance hole, and there is provided a nut on the bolt which may be tightened to secure the first and second members one against the other.

27. A structural assembly substantially as hereinbefore described with reference to the accompanying drawings.