GB2266913A

GB2266913A - Roller shutter track joint

Info

Publication number: GB2266913A
Application number: GB9300888A
Authority: GB
Inventors: David John Cregan
Original assignee: NORTHERN DOORS
Current assignee: NORTHERN DOORS
Priority date: 1992-05-12
Filing date: 1993-01-18
Publication date: 1993-11-17
Anticipated expiration: 2013-01-18
Also published as: GB2266913B; GB9300888D0

Abstract

A joint (1) for the top track (2) of a horizontally deployable roller shutter, the track (2) having a longitudinally extending gap and being constructed to desired length from a plurality of lengths (4), the adjacent ends (5) of which are spaced apart to provide an expansion gap (6), with adjacent end zones (7) of the track lengths (4) joined together by joint plates (8) bolted to the track lengths by bolts/nuts (9) incorporating fusible elements (10) and passing through slotted holes (13), while the expansion gap (6) is bridged by two bridging rails (14) having mutually facing and spaced apart longitudinal edges (16) to define a longitudinally extending gap (17) contiguous with the gap of the track lengths (4). <IMAGE>

Description

ROLLER SHUTTER TRACK JOINT This invention relates to a track joint for a roller shutter, particularly a shutter having fire resistant qualities, of the kind operable about a vertical axis and hence deployable in a generally horizontal direction, principally to prevent the spread of fire between large spans.

Such a roller shutter - comprising a plurality of rollers from which depend a plurality of hangers on which are suspended a plurality of laths making up the so-called curtain - is supported from, and guided wholly or principally by, top track, and clearly in the event of fire the top track needs to maintain its integrity and remain stable when subjected to elevated temperatures. As the top track is conventionally an elongate creel section, and thus will suffer from there expansion, particularly in length, at elevated temperatures, it is therefore necessary to incorporate expansion joints within the track at predetermined centres to prevent buckling which might otherwise occur to prevent or restrict the essential closing action of the shutter.

According to the present invention there is provided a joint for the top track of a horizontally deployable roller shutter, the track having a longitudinally extending gap and being constructed to desired length from a plurality of lengths, the adjacent ends of which are spaced apart to provide an expansion gap, with adjacent end zones of the track lengths joined together by joint plates bolted to the track lengths by bolts/nuts incorporating fusible elements and passing through slotted holes, while the expansion gap is bridged by two bridging rails having mutually facing and spaced apart longitudinal edges to define a longitudinally extending gap contiguous with the gap of the track lengths.

Thus, smooth operation of the shutter is maintained at each joint by the two bridging rails to ensure the smooth passage of the curtain and roller assembly from one section of the track to the other without inhibiting the requirement for the track sections to slide together during expansion.

The track, and specifically each track length, preferably comprises an inner track element, generally of inverted "U"-shape the parallel limbs of which are provided with inturned flanges which are spaced apart to define the longitudinal slot for the movement, with little or no friction of the hangers passing through the gap, with the rollers being captivated, usually as part of a carriage, within the "U" section, while the track/track length is completed by a side plate secured externally to each parallel limb.

Each bolt/nut preferably comprises steel washers and fusible plastics washers, which when melted upon a prescribed temperature being reached, allow free movement of the joint sections through the slotted holes.

The invention will now be described in greater detail by way of example, with reference to the accompanying drawings, in which; Figure 1 is a side elevation of a joint in accordance with the invention; Figure 2 is a section on the line II - II of Figure 1; and Figure 3 is a plan view on the line III - III of Figure 1.

In the drawings, a roller shutter track joint 1 for a top track 2 of a horizontally deployable roller shutter - the conventional rollers, hangers and laths not being illustrated.

The top track 2 has a longitudinally extending gap 3 for passage of the hangers with clearance, the track 2 being constructed to desired overall length from a plurality of track lengths 4 with adjacent ends 5 spaced apart to define an expansion gap 6. Adjacent end zones 7 of each adjacent track length 4 are jointed together by common joint plates 8, one at each lateral side, which plates 8 are bolted to the end zones 7 of the track lengths 4 by bolts/nuts 9 incorporating fusible plastics washers 10 and passing through circular holes 11 in the end zones 7 in side plates 12 forming part of the track 2 and through slotted holes 13 in the joint plates 8 so that, at elevated temperatures of the track lengths 4, the latter may readily expand longitudinally, thus diminishing the expansion gap 6, and with the bolts/nuts 9 moving along the holes 13.

The gap 6 is bridged by two bridging rails 14 secured by welds 15 to the insides of the joint plates 8 and having mutually facing and spaced apart longitudinal edges 16 to define a longitudinally extending gap 17 contiguous with the gap 3 of the track 2.

The track 2 also comprises an inner track element 18 of inverted "U"-shape, the parallel limbs 19 of which are provided with inturned flanges 20 which are also spaced apart so as not to obstruct the gap 17, and seat on upper surfaces of the bridging rails 14 which are provided with an upwardly directed, longitudinally extending lip 21 to retain the track element 18 in position.

Claims

1. A joint for the top track of a horizontally deployable roller shutter, the track having a longitudinally extending gap and being constructed to desired length from a plurality of lengths, the adjacent ends of which are spaced apart to provide an expansion gap, with adjacent end zones of the track lengths joined together by joint plates bolted to the track lengths by bolts/nuts incorporating fusible elements and passing through slotted holes, while the expansion gap is bridged by two bridging rails having mutually facing and spaced apart longitudinal edges to define a longitudinally extending gap contiguous with the gap of the track lengths.

2. A joint as claimed in Claim 1, wherein the track, and specifically each track length, comprises an inner track element, generally of inverted "U"-shape the parallel limbs of which are provided with inturned flanges which are spaced apart to define the longitudinal slot for the movement, with little or no friction of the hangers passing through the gap, with the rollers being captivated, usually as part of a carriage, within the "U" section, while the track/track length is completed by a side plate secured externally to each parallel limb.

3. A joint as claimed in Claim 1 or Claim 2, wherein each bolt/nut comprises steel washers and fusible plastics washers, which when melted upon a prescribed temperature being reached, allow free movement of the joint sections through the slotted holes.

4. A joint substantially as hereinbefore described with reference to the accompanying drawings.