IMPROVEMENTS IN AND RELATING TO ROLLER DOOR ASSEMBLIES

Abstract: A roller door assembly comprises a roller door (10) having on its vertical edges restraining means (12, 112), at each edge of the door opposing members forming a gap therebetween, the restraining (12, 112) means being on one side of the gap with the door on the other side thereof, whereby upto a desired pressure or force on the door the restraining (12, 112) means cannot pass through said gaps but at said desired pressure or force the restraining means are compressed and/or the gap expands for the restraining (12, 112) means to pass through said gaps to release the door.

Description: This invention concerns roller door assemblies. Roller doors are often used to close large openings in garage, warehouse and factory situations, where space may be usefully saved. Such roller doors of continuous sheet or slatted construction are attached to a roller positioned horizontally over a door opening so that opening and closing of the door is by vertical movement thereof. The edges of such doors usually run in guides but increased pressure on the door such as in higher than average wind speeds can cause the door to bow and its edges to come out of the guides. The door can then flap about dangerously. Proposals have been made for providing restraining members on the edges of such doors that cannot pass through the guides, see for example, EP-A-033.199 which shows a roller door have edge restraining means releasable from gaps at opposed edges of the door when a certain impact or pressure is applied against the door. A problem with these is that under very high pressure conditions such as wind speeds approaching gale force or upon impact by a vehicle, the door restraining members hold the door in place but only at the risk of damage to the door such as by tearing. The object of this invention is to provide a roller door assembly that eliminates or at least mitigates the aforementioned disadvantage. According to the invention there is provided a roller door assembly wherein vertical edges of the door have restraining means thereon whereby upto a desired pressure or force on the door the restraining means cannot pass through gaps at the edges of the door but at said pressure or force the restraining means are compressed and/or the gap expands for the restraining means to pass through said gaps to release the door, characterised in that the door has a plurality of restraining means spaced at intervals along each of said opposed vertical edges of the door. The preferred restraining means is compressible and may be solid or hollow. Rubber, elastomeric or plastics rod or tubing are suitable materials for the restraining means. The restraining means may also be of multipart form, such as in two parts, the parts being attached to edges of the door to present a generally smooth, say curved, surface towards the faces of the gap. Suitable plastics materials for the restraining means include PTFE, nylon, polyethylene and similar materials. Thus, upto a certain force or pressure on the door, as it bows or distorts, the restraining means are pulled towards the gaps but are too large to pass through the gaps. However, above a certain pressure the distortion or bowing of the roller door will be such that the restraining means are pulled into the gaps and compressed so that they pass through the gaps. Alternatively or additionally, the gaps may be provided by two facing members, say V-shaped, of resiliently deformable material, whereby upto a certain pressure on the door, the restraining means are retained, but above that pressure the facing members deform and optionally the restraining means are compressed, whereby the restraining means escape through the gaps. The roller doors of the invention may have as many such restraining means on each side edge thereof as desired. The size of the door will probably be the main factor in the selection of the number and positions of the restraining means. The size of the restraining means and its compressibility and optionally the deformability of the members of forming the gaps may also be important factors in their selection depending, for example, on how much force or pressure the roller door is intended to withstand before the restraining means are released past the gap. The invention is particularly concerned with continuous sheet roller doors and so another factor that may be of importance is the strength of the material used for the door. A preferred material is polyester fabric, such as of the type used for conveyor belting but obviously other suitable materials may be used for the doors of the invention, such as polyvinyl chloride. It is proposed that for a polyester roller door wind speeds of upto 80m.p.h. equivalent to a force of 0.115 lb/sq inch, preferably upto 60m.p.h. equivalent to a force of 0.063 lb/sq inch, be accommodated without the release of the restraining means but that above such a force the restraining means be released past the gap. In this way damage such as tearing of the door may be eliminated or at least instances thereof reduced. This invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:- Figure 1 is a horizontal section through one side of a roller door assembly; Figure 2 shows part of an edge portion of the roller door of Figure 1. Figure 3 is a horizontal section through one side of an alternative roller door assembly; and Figure 4 shows part of an edge portion of the roller door of Figure 3. Referring to Figures 1 and 2 of the drawings, a continuous roller door 10 of say polyester material, such as of the type used in the manufacture of conveyor belts is attached at its upper edge to a roller (not shown) on which the door rolls up as it opens. When the door 10 is being closed the edge portions of the door run between support posts 11 each faced with wear resistant material. At the extreme edges of the door are attached at spaced intervals pieces of rubber tubing 12 by means of pieces 13 of polyester material wrapped therearound and rivetted to the edges of the door. The rubber tubing pieces are outward of vertical facing V-shaped guides 14 that form between them a narrow opening 15. The guides 14 may be slightly resiliently deformable. Turning to Figures 3 and 4, a continuous roller door 110 of polyester material is attached at its upper edge to a roller not shown on which the door rolls up as it opens. When the door 110 is being closed the edge portions of the door runs between supports posts 111 each faced with wear resistant material. At extreme edges of the door are rivetted at spaced intervals pieces 113 of polyester material one each side of the door, the pieces 113 extending beyond the edges of the door. On each side of said piece is attached a plastics piece 112 of semi-circular section, a pair of said pieces together forming a generally circular section restraining means. The restraining means are outward of vertical facing V-shaped guides 114 that form between them a narrow opening 115. The guides 114 may be slightly resiliently deformable. An advantage of the embodiment of Figures 3 and 4 is that as the restraining means presents generally smooth surfaces to the guides friction is reduced and hence loads on motors for raising and lowering the door are reduced. The doors of both the illustrated embodiments operate in the same fashion. Under conditions when there is little or no wind or other pressure on the closed door these guides play no part in the operation of the door. However, in stronger winds or pressure say upto about 80m.p.h. (0.115 lb/sq in), preferably only upto 60m.p.h. (0.063 lb/sq inch.) the door will bow and the rubber or plastics tubing pieces will abut against the V-shaped guides to hold the door in place. If the pressure on the door is greater than about 0.115, preferably 0.063 lb/sq in such as in wind speeds greater than 80m.p.h. preferably 60m.p.h. or upon impact of a vehicle, that pressure will cause the rubber tubing or plastics pieces to be compressed against the guides and so the resultant bowing of the roller door pulls the rubber tubing or plastics pieces into the guides with sufficient force to compress the tubing or plastics pieces and possibly also deform the guides 14 slightly so that the tubing or plastics pieces pass through the narrow gap between the guides. This releases the roller door and allows it to bow or distort according to the force applied so that damage, such as tearing is avoided.

Claims: A roller door assembly comprising a roller door (10) having on its vertical edges restraining means (12, 112), at each edge of the door opposing members (14, 114) forming a gap (15, 115) therebetween, the restraining means being on one side of the gap with the door on the other side thereof, whereby upto a desired pressure or force on the door the restraining means cannot pass through said gaps but at said desired pressure or force the restraining means are compressed and/or the gap expands for the restraining means to pass through said gaps to release the door, characterised in that the door has a plurality of restraining means spaced at intervals along each of said opposed vertical edges of the door. A roller door assembly as claimed in claim 1, wherein the restraining means are of tubing. A roller door assembly as claimed in claim 1, wherein the restraining means are of solid material. A roller door assembly as claimed in claim 1, 2 or 3, wherein the door is made of polyester fabric. A roller door assembly as claimed in any one of claims 1 to 4, wherein the door is made of polyvinyl chloride.

Inventors: ASHLEY, PAUL, CHAPMAN, JOHN UNITE
Applicants: CLARK DOOR LIMITED
Application year: 1987
Main classification: E06B9
IPC codes: E06B9