GB2369150A

GB2369150A - Break-away system for roller door assemblies

Info

Publication number: GB2369150A
Application number: GB0122350A
Authority: GB
Inventors: Paul Ashley
Original assignee: Clark Door Ltd
Current assignee: Clark Door Ltd
Priority date: 2000-09-22
Filing date: 2001-09-17
Publication date: 2002-05-22
Anticipated expiration: 2021-09-17
Also published as: GB0023309D0; GB2369150B; GB0122350D0

Abstract

A roller door assembly comprises a roller door (2) and, at opposing sides of the door, guide members (10, 12) arranged to form an opening for passage of the door's vertical edges (2a), the guide members being configured to move outwardly upon application of pressure to the door thereby releasing the edges from the guides. A spring mechanism, for example in the form of retaining member, retractable spring piston and cam arrangement, may act against the guide members whereby a predetermined amount of pressure has to be applied to enable the guide members to move outwardly.

Description

Title: Improvements in and relating to roller door assemblies DESCRIPTION The present invention relates to an improved roller door assembly.

Fast-acting fabric roll-up doors have been used for many years to assist the passage of goods-handling equipment, such as fork-lift trucks, between various zones in industrial and, sometimes, commercial applications. Such roller doors are of a continuous sheet or slatted construction and are attached to a motor drive roller positioned horizontally over a door opening whereby opening and closing of the door is by way of vertical movement of the sheet. Suitable tensioning and counterbalancing means may be provided to assist in the operation of the door, such as those described in our U. K. Patent No. 2200157.

The edges of such doors usually run between guide members that are provided at each side of the opening but an increase in pressure on the door, such as high speed winds, can cause the door to bow which may result in its edges coming out of the guides. Restraining means, such as the slightly resilient, deformable V-shaped guides detailed in our U. K. Patent No. 2196370, may be provided to withstand such pressures and thereby hold the door in place but do allow for the door to become free from the guides upon application of very high pressure, such as is experienced upon impact by a vehicle, thereby avoiding damage to the door. These types of restraints are generally employed in roller door assemblies that are to be provided externally and are therefore vulnerable to prevailing weather conditions.

Roller door assemblies for use internally do not require such restraints to be held in place. However, operators of goods-handling equipment frequently do not wait until the door is fully open before passing through the opening. This results in the truck colliding with the door thereby forcing the sheet out of the guides.

Mechanisms that have been employed for retaining the door in the guides include a tensioning device fixed between a beam provided at the base of the sheet and the guides that is broken on impact of vehicle with the door and the provision of a stiff rubber member that is attached to the beam and extends into the opening of the guides. The rubber member bends on impact of an object to release the door from the guides.

However, the types of restraints provided hereto have hindered the re-insertion of the sheet into the guides. Additionally, the retaining force provided by the restraints is not variable to take account of, for example, different wind conditions that may be experienced internally, due to draughts or the like.

It is an object of the present invention to provide a roller door assembly that eliminates, or at least alleviates, the aforementioned disadvantages.

Accordingly, the present invention provides a roller door assembly comprising a roller door and, at opposing sides of the door, guide members arranged to form an opening for passage of the door's vertical edges, the guide members being configured to move outwardly upon application of pressure to the door thereby releasing the edges from the guides.

Preferably, a spring mechanism acts against the guide members whereby a predetermined amount of pressure has to be applied to the door to compress the spring and thereby enable the guide members to move outwardly. It is preferable that the guide members may move outwardly in either direction depending upon the direction of the application of pressure to the door.

Each guide member on each side of the door may be formed as an integral component having an opening therein for passage of the edges of the door and being hinged to allow movement of the member.

Alternatively, two guide members may be provided on each side of the door wherein the guide members are arranged to form an opening therebetween for passage of the door. Preferably, each guide member has a pivot point about which the member may rotate upon application of pressure to the door.

More preferably, the two vertical guide members each have an end section substantially opposite the opening that overlap one another. Preferably, a further retaining member is provided for abutting the overlapping sections, the restraining member being fixedly secured to side posts of the door assembly.

Preferably, the spring mechanism, for example, in the form of a retractable spring piston, is fixed to the retaining member and co-operates with a contact surface on one of the guide members thereby imparting a biasing force to the member to resist movement thereof. Preferably, one of the guide members is provided with a cam attached thereto that co-operates with the piston to resist movement of the side member. In this manner, a predetermined amount of pressure on the guide member pushes the cam against the piston thereby moving the piston to allow rotation of the guide member.

Preferably, the amount of pressure exerted by the spring mechanism to resist movement of the side guide members is variable. It is to be appreciated that a number of the spring mechanisms (i. e. such as the retaining member, retractable spring piston and cam arrangement) may be placed at spaced apart intervals up the side guide members, the number depending upon the height of the door.

The components of the door assembly may be comprised of any suitable materials. The door is preferably of a fabric material. More preferably, the lower edge of the door is provided with a beam, such as an aluminium extrusion clamped onto the fabric material. Preferably, the sides of the fabric material extend past the outer ends of the beam. A safety beam, for example, of a resilient foam or sponge, may extend from the beam. The side guide members are preferably comprised of sheet steel.

Photocells may also be provided at opposing sides of the door for sending a beam of light across the opening. In this manner, when an object breaks the path of the light, the photocells activate a switch to prevent or reverse movement of the door.

Alternatively or additionally, the safety beam may be provided with pneumatic tubes connected to a pneumatically operated electric switch. An increase or decrease in the pressure in the tubes, for example, caused by an impact with the beam, causes the switch to stop or reverse the motor.

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings in which: Figure 1 shows schematically a roller door assembly according to one embodiment of the present invention; Figure 2 shows a horizontal section through one side of the door assembly shown in Figure 1; and Figure 3 shows a horizontal section through the side guide members for one side of the roller door assembly shown in Figure 1.

Referring to the accompanying drawings, a roller door assembly according to one embodiment of the present invention is illustrated comprising a continuous sheet 2 of, for example, a fabric material, which is attached at its upper edge to a roller 4 horizontally mounted over a door opening. The roller 4 is arranged to be motor driven in order to roll the sheet onto or off the roller thereby opening or closing the door. When the door 2 is being closed, the side edge portions 2a of the door run between door frame members 6 that are provided along the sides of the opening and have guide members 10,12 for retaining the sheet therein.

The bottom edge of the door carries a beam 8, such as a rectangular aluminium extrusion, which clamps the curtain fabric and assists in keeping the sheet taut. The sides of the fabric sheet extend past the outer ends of the beam so that they may pass between the guide members 10,12. The beam 8 also carries a safety beam 14 which is constructed principally of resilient foam or sponge material.

The roller door assembly according to one embodiment of the present invention includes a side guide restraint assembly provided on each side of the door that retains the door within the guides under normal conditions but allows the door to come out of the guides upon the application of a certain amount of pressure to the door. The restraint assembly also allows the door to be placed back between the guide members easily and with minimal effort. Each assembly comprises the two side guide members 10,12, a retaining member 18 and a spring mechanism 26,27, 28 acting on a cam 24 that is fixed to the side guide member 10 (see Figures 2 and 3).

The side guide members 10,12 extend vertically up each side of the opening and are made of long sheets of steel that have been bent into the required configurations to provide an opening 16 between the guide members for passage of the door. Side guide member 10 is comprised of three continuous sections lOa, lOb and lOc. Section lOa is generally L-shaped, section lOb generally U-shaped and section 10c generally C-shaped. Side guide member 12 is comprised of two continuous sections; a generally L-shaped section 12d and a generally S-shaped section 12e. The members 10 and 12 are arranged such that the long limb of the Lshaped section lOb abuts the end part of the S-shaped section 12e. The short limb of the L-shaped section 10d abuts the vertical support post 6.

An additional retaining member 18, also comprised of sheet steel, in the general shape of an elongated Z, has a first limb 18a and a second limb 18b that are linked by a cross bar 18c. The first limb thereof is fixed along its edge to the support frame 6 whilst the other limb 18b abuts the end part of the S-shaped section 12e of member 12 (see figure 3 in particular). The side guide member 10 has cam 24 fixed to the short limb of its L-shaped section and a retractable spring piston 26,27 housed inside a guide cylinder 28 extends from the first limb of the retaining member 18 such that, in the normal position, it locks against the cam 24 to hold the assembly in place.

In this manner, the fabric sheet of the door 2 normally lies in the opening 16 between the side guide members 10 and 12 and is able to pass vertically between the guides during opening and closing of the door. However, upon application of pressure, the guide members are able to pivot about points 30 or 32 to allow the door to become free from the guides. If the door is struck in the direction of arrow"A" guide member 10 is able to pivot about point 30 thereby freeing the door from the guide and allowing the door to swing away from the impact and avoid or minimize damage to the door. Similarly, if the door is struck in the direction of arrow"B"the guide 12 will pivot about point 32 thereby releasing the door from the guides.

The presence of the sprung plunger 26,27 acting against cam 24 fixed to the side member 10 prevents movement of the members upon application of small pressures. However, if the door is hit with force, for example a truck collides with the door, the pressure on side member 10 or 12 causes the cam to act against the springloaded plunger thereby allowing the side member to move about point 30 or 32 respectively.

The door is easily placed back between the guides by repositioning the side members by moving the side guide member 12 back to its original position and relocating side guide 12 which locks the assembly back together by the long limb of the L-shaped section lOa pressing the end part of the S-shaped section of side member 12 against the second limb 18b of the retaining member.

It is to be appreciated that the number of cam and sprung plunger arrangements provided on a side guide assembly may vary depending upon the height of the door. The arrangements may be placed at spaced apart intervals along the length of the side members.

Additionally, the assembly may include photocells (not shown) in both sides of the door to prevent the door closing when an object has broken the light path and accordingly, the side guides are open (for example, after a collision). A break in the beam produced by the photocells will prevent the now fully open door from returning to the closed position until the guide members have been returned to their original locations.

The components of the roller door assembly may be made of any suitable materials. The guide members are preferably made of sheet steel but may be made of, for example, a reinforced plastics material.

Alternatively or additionally the safety beam at the base of the door may contain two pneumatic tubes (not shown), one in each of the lower quarters of the beam for connecting to a pneumatically operated electric switch. The switch may be arranged to stop and/or reverse the motor that operates the door roller upon an increase or decrease in pressure within pneumatic tubes. Such an increase in pressure will be caused by impact of the safety beam upon an object or person obstructing downward movement of the door.

The guide restraint assembly employed in the roller door system of the present invention allows the fabric sheet and beam making up the door to be pushed out of the side guides in either direction without damaging any of the door components. This is achieved by the use of an interlocked and variable rate spring loaded side guide assembly which, whilst restraining and guiding the door fabric in normal use, can be set to release the door fabric and beam when a certain amount of horizontal force is applied to the door. The door will, when struck in this way, be forced to a fully open position due to the cam pressing against the piston to compress the spring to allow the side guides to pivot about their hinges. The door will remain in this position until the guide members are manually reset. This process can be undertaken by a single person without the use of tools or materials and may be completed within seconds. Once the side guides have been returned to their original configuration, the door will automatically return to full operation without further intervention.

Claims

CLAIMS 1. A roller door assembly comprising a roller door and, at opposing sides of the door, guide members arranged to form an opening for passage of the door's vertical edges, the guide members being configured to move outwardly upon application of pressure to the door thereby releasing the edges from the guides.
2. A roller door assembly as claimed in claim 1 wherein a spring mechanism acts against the guide members whereby a predetermined amount of pressure has to be applied to compress the spring and thereby enable the guide members to move outwardly.
3. A roller door assembly as claimed in claim 1 or claim 2 wherein the guide member may move outwardly in either direction depending upon the direction of the application of pressure to the door.
4. A roller door assembly as claimed in claim 1,2 or 3 wherein each guide member on each side of the door is formed as an integral component having an opening therein for passage for the door and being hinged to allow movement of the member.
5. A roller door assembly as claimed in claim 1,2 or 3 wherein two guide members are provided on each side of the door, the guide members being arranged to form an opening therebetween for passage of the door.
6. A roller door assembly as claimed in claim 5 wherein each guide member has a pivot point about which the member may rotate upon application of pressure to the door.
7. A roller door assembly as claimed in claim 6 wherein the two guide members each have an end section substantially opposite the opening that overlap one another.
8. A roller door assembly as claimed in claim 7 wherein a retaining member is provided for abutting the overlapping sections.
9. A roller door assembly as claimed in claim 8 wherein the retaining member is fixedly secured to side posts of the door assembly.
10. A roller door assembly as claimed in claim 8 or claim 9 wherein a retractable spring piston is fixed to the retaining member and co-operates with a contact surface on one of the guide members thereby imparting a biasing force to the member to resist movement thereof.
11. A roller door assembly as claimed in claim 10 wherein one of the side guide members is provided with a cam attached thereto that co-operates with the piston to resist movement of the member.
12. A roller door assembly as claimed in claim 11 wherein multiple spring mechanisms consisting of the retaining member, retractable spring piston and cam arrangement, are placed at spaced apart intervals up the side guide members.
13. A roller door assembly as claimed in any one of the preceding claims wherein the door is a fabric material.
14. A roller door assembly as claimed in claim 13 wherein a lower edge of the door is provided with a solid beam clamped onto the fabric material.
15. A roller door assembly as claimed in claim 14 wherein the sides of the fabric material extend past the outer ends of the beam.
16. A roller door assembly as claimed in claim 14 or claim 15 wherein a safety beam of resilient foam or sponge extends from the beam.
17. A roller door assembly as claimed in any one of the preceding claims wherein the side guide members are made of sheet steel.
18. A roller door assembly as claimed in any one of the preceding claims, wherein photocells are provided at opposing sides of the door for sending a beam of light across the opening whereby if an object breaks the path of light, the photocells activate a switch to prevent or reverse movement of the door.
19. A roller door assembly as claimed in any one of claims 16 to 18 wherein the safety beam is provided with pneumatic tubes connected to a pneumatically operated electric switch whereby an increase or decrease in the pressure in the tubes causes a switch to stop or reverse movement of the door.
20. A roller door assembly substantially as hereinbefore described and with reference to Figures 1 to 3 of the accompanying drawings.