GB2291674A - Flexible door with support bar - Google Patents

Abstract

A flexible door 10, shown in the closed position in figure 1, which may be one of a pair with door 11, each preferably formed as a pair of spaced panels (15, 16, figure 2), has a driven safe edge (17, figure 2) and means to retract the door to the open position of figure 8. Between the safe edge and the retracting means are wind bars 22, which are also driven. A support bar 63, which may be further supported by rail 65, spans the opening 12 intermediate the top and bottom of the opening and forms a support along which the safe edge may slide. The safe edge 17 may be provided with a carriage (64, figure 9) having a bearing formation (67, figure 9) complementary to the circular section of support bar 63 on which it slides. <IMAGE>

Description

DOOR ARRANGEMENTS Field of the Invention The present invention relates to door arrangements and methods of operating door arrangements. The invention is particularly, although not exclusively, applicable to side opening door arrangements.

Background to the Invention In a known side opening door arrangement two flexible door panels are wound onto different drums located on opposite sides of the door aperture. The free end of each panel is provided with a rigid safe edge which is connected to a drive assembly at the top of the door aperture.

In use, the safe edges are powered towards each other, pulling their associated door panels off the rollers against a resilient force. The safe edges then meet in the middle to close the aperture. To open the arrangement, the safe edges are powered away from each other and the resilient force acting on the rollers winds up the panels.

These doors are usually located to divide two interior parts of a building and the safe edges are not guided at their lower end: the safe edges are rigidly connected to the drive assembly and extend downwardly therefrom. Any channel guide at the lower end of the doors would quickly become clogged and/or be a safety hazard. The doors are operated by approaching vehicles (such as fork lift trucks or articulated lorries) either by the vehicle operator pressing a remote actuator or automatically by an inductive loop set in the ground before the door which detects the vehicle.

When the doors are closed, the wind on the outside of a building can exert such a force on the doors that the resilient force urging the doors onto the rollers is overcome and more of the flexible door is pulled off each roller to cause the doors to balloon into the building which can detract from the efficiency of the door or cause the door to break. Additionally, as the free edge of each door is powered back to the closed position by a positive drive, with the spring in the roller pulling in the flexible door, if the roller causes the flexible door to be moved in at a lesser rate than the free end of the door the flexible door will be trapped by the free end against the side of the opening without being wound fully home on the roller.

One attempt to obviate this problem is set out in GB 2 271 383 in which an adaptive positive drive mechanism is provided.

This known arrangement works satisfactorily in most instances. However, for some applications the apertures to be covered by the doors are too large for this arrangement to be able to cope with the wind forces applied. By way of example, at an airport bonded warehouse doors for loading bays can be 5m high by Sm wide and the open spaces associated with airfields results in high wind speeds. In these circumstances the bars at the top of the door arrangement which support the doors, can become buckled by the forces exerted by the winds.

Furthermore, in bonded warehouses there will be security shutters (or equivalent) between these side opening flexible door panels and the prevailing winds. When the security shutters are opened, usually first thing in the morning, the wind impacts the doors with a large force.

Another problem associated with bonded warehouse applications (and others) is that of security at loading bays. With a vehicle in the bay there is considerable space between to the door frame through which an intruder can gain entry.

It is an object of the present invention to attempt to overcome or obviate at least some of these disadvantages.

Summarv of the Invention According to the present invention, there is provided a door arrangement comprising a flexible door movable between a first position, in which the door extends at least partially over an opening and a second, retracted position, in which the flexible door comprises a relatively rigid support arranged to move with the door between the first and second positions and means to support the door, which support means is located intermediate the top and bottom of the opening.

The support means is, therefore, located such that there is part of the opening both above and below the support means. This location of the support means provides additional support against high wind forces. The support means provides a reduced cantilever against prevailing wind forces relative to the size of the opening.

Normally, in the vicinity of the top of the door, there is a drive assembly for moving the door between the first and second positions. The drive assembly will usually include a further support means comprising a bar to which is coupled the relatively rigid support.

Suitably, the door is a side opening door which, preferably, in a bi-parting door.

The support means is, preferably, located such that the gap of the opening below the support means is greater than the gap of the opening above the support means.

Suitably, the support means is coupled to the relatively rigid support.

Suitably, the support means is connected to the relatively rigid support by a boss.

Suitably, the support means comprises a bar which, conveniently, is circular in cross-section.

Suitably, the support means is reinforced by a rail to which, preferably, it is connected at a plurality of locations along its length.

Suitably the support means is substantially horizontal.

Normally this will mean that the support means is parallel to the further support means.

Conveniently, the relatively rigid member includes sensor means for detecting the presence of an object in the path of the relatively rigid member as the door moves from its second to its first position. Suitably, if an object is detected, means are provided for halting the door before it reaches the object. Preferably for distance before the object the door is halted is less than 30cm, which should prevent the passage of people between the object and the door.

Preferably, the door has an outside and an inside relative to a structure such as a building and the support means is located on the inside of the plane of the opening.

Preferably, the reinforcing rail is on the inside of the support means. Thus, vehicles can approach up to the plane of the opening (to which a loading clock may extend) without hitting the support means even if they are taller than it.

Conveniently, the flexible door is wound back on to a roller when it is retracted.

Suitably the support means in the lowest support means of the door for the relatively rigid support.

According to a second aspect of the present invention, there is provided a door arrangement comprising a flexible door movable between a first position, in which the door extends at least partially over an opening and a second, retracted position, in which the flexible door comprises a relatively rigid support arranged to move with the door between the first and second positions, and means to sense the presence of an object in the pathway of the door between its second and first positions.

Suitably, the sensing means is coupled to means for halting the door before it reaches the detected object.

Preferably, the door is halted less than about 30cm from the detected object, which distance is less than that normally passable by an intruder.

Suitably, the sensing means comprises flexible arms extending from the door in the vicinity of its direction of travel from the second to first positions. Preferably, the arms extend forwards (in an inner to outer sense) of the path of the door so that the arm does not detect the other side of the door frame/casing or the or another door.

According to a third aspect of the present invention there is provided a method of operating a door arrangement, which method comprises providing a door arrangement according to the second aspect of the invention and sensing the presence or absence of an object in the door pathway.

Suitably, the method includes the step of halting the door before the second object, preferably less than about 30cm from the sensed object.

The present invention includes any combination of the herein described features or limitations.

Brief Description of the Drawings The present invention may be carried into practice in various ways but one embodiment will now be described, by way of example, with reference to the accompanying drawings; in which: Figure 1 is a schematic front view of a pair of flexible door panels 10 and 11 which can be wound towards or away from each other to open or close a doorway 12; Figure 2 is a schematic sectional plan view taken on the lines 2-2 of Figure 1; Figure 3 is a detailed front view of the operational part of the door 10 in the region designated 3 in Figure 1; Figure 4 is a schematic perspective view of the mechanism whereby the door 10 can be powered to the open or closed position; Figure 5 is a front view of the sliding members 13 and 14 which power portions of the door 10;; Figure 6 is a schematic plan view of a plate 42 showing the cooperation of a cap screw 46 with a slot 47 to control the winding up of the flexible door panel; Figure 7 is a schematic perspective view of part of a guide channel 50 for the lower portion of the safe edge and wind bar; Figure 8 is a schematic front view similar to that of Figure 1, but with the door panels 10 and 11 retracted; Figure 9 is a detailed side view of the carriage 64 on the bar 63, and Figure 10 is an enlarged schematic illustration of a detail of the lower part of one of the safe edges 17.

Description of the Preferred Embodiment As shown in Figures 1 and 2, two flexible door panels 10 and 11 are provided which can be pulled off drums extending upwardly on either side of the doorway 12 to meet in the middle, or rolled back onto the drums to open the doorway. Each panel 10 or 11 when fully closed covers an area of about 2.5m x 5m. As shown in Figure 2, each door comprises a pair of spaced flexible panels 15 (outer) and 16 (inner) which are connected together at their free ends by a safe edge 17, with each panel being able to be wound onto or off an associated drum 18 and 19 respectively. The drums 18 and 19 of each door have side by side meshing gears 20 (shown in Figure 3) at a region above their extent whereby, by powering one gear 20 associated with one of the drums in one direction, the other drum is caused to rotate in the opposite direction.

The doorway 12 is located on the outside of a building such as a bonded warehouse or on an inner door exposed to wind forces, and accordingly, when the wind blows in the direction shown by arrows 21 in Figure 2, the outer panel 15 will tend to deflect inwardly, as shown in chain lines, to cause "bagging" of the panel. If that inwards movement were unchecked then, if the safe edges 17 were powered back, the panels would tend to become trapped between the safe edge and the drums without the panel being fully wound back onto the drum. Alternatively or additionally, excessive inwards movement of the panel 15, when the doors are closed, will pull the safe edges away from each other or pull an excessive amount of the panel off the drum.To assist in limiting the bagging of the panel, both in the fully closed position and when the door is being opened, a wind bar 22 is provided between the panel 15 and 16 with the bar 22 being located approximately halfway between the safe edge 17 and the drums 18 and 19 regardless of whether the doors are fully or partially open. Each wind bar is powered away from and towards the associated drum, as are the safe edges in a manner to be described below.

The wind bars 22 and the safe edges 17 are powered between an open and closed position by a motor 33 shown schematically in Figure 3 which engages a driven cog 23 to cause clockwise or anticlockwise rotation of coaxial grooved wind bar and safe edge drums 24 and 25 respectively. A chain may extend around the corresponding cog associated with the drums of the other door to enable synchronised operation of both doors from a single motor.

As shown in Figure 4, a wind bar cable 26 is wound around the wind drum a few turns (to ensure that the cable will not slip on the drum) with a loop of that cable extending around a free running pulley 27. Although the cable 26 is designed not to stretch it is inevitable that, in use, a small amount of stretch will occur and accordingly each end of the cable is attached to a different end of a tension spring 55 such that, should stretching of the cable occur, that will be taken up by the spring contracting slightly. Similarly a safe edge cable 28 is wound around the safe edge drum 25 with a loop of that cable passing around a pulley 29 and with the ends of the cable being secured to opposite ends of a spring 30.

The diameter of the safe edge drum 25 is twice that of the wind bar drum 24 and accordingly the straight extent of the safe edge cable 28 will move at twice the speed of the wind bar cable 26. The edge cable 28 and the wind cable 26 are secured to the safe edge carriage 14 and the wind bar carriage 13 respectively, as shown in Figure 5.

The safe edge carriage 14 is guided by a pair of linear roller bearings 31 which slide on spaced parallel bars 32, 36. Any tendency for the safe edge and the associated carriage to twist about the bars 32, 36 is resisted by rollers 34 located on an extension 35 of the carriage which abut with the underside of one of the bars 32 and the top of one of the bars 36 for the other carriage.

Similarly, the wind bar carriage is guided by a pair of linear roller bearings 37 with rollers 38 on an extension 39 resisting twisting of the wind bar or the carriage.

When the door 10 is in the open position, the two carriages will overlap each other partially with the extension 39 of the wind carriage extending alongside the carriage 14 and the extension 35, when viewed from the front. Similarly the extension of the safe edge carriage of the other door 11 is located between the bars 36 such that the extension of safe edge carriages from each door can overlap each other.

Each drum 18 and 19 is connected to a keyed bullet shaft 40 (which is constrained to rotate with the drive cog 23) via a torsional spring 41. The spring 41 is fixed at its upper end to a plate 42, and that plate is welded to the upper end of the drum 18. The lower end of the spring is fixed to a disc 43 which is welded to a shaft 44 into which the bullet shaft extends such that the two shafts are constrained to rotate with each other. A pair of spaced parallel bearings 54 are provided between the shaft 44 and the drum 18 to permit relative pivotal movement.

The lower end of the drum (not shown) is mounted in coaxial bearings to enable rotation of the drum.

The plate 42 is able to slide relative to an overlapping plate 45. Accordingly, considering the normal operation of the door, without wind loading, as the door is moved from the closed to the open position the diameter of the drum will increase as the panel is taken up, and accordingly the drum will undergo a slightly smaller degree of rotation than the shaft 40. However, the spring connection between the shaft 40 and the drum urges the drum to wind up with the sheet being in tension. However, if wind loading occurs during opening of the door that relative movement may be excessive thereby permitting bagging of the panel. To prevent such excessive movement, a cap screw 46 fast with the plate 45 and the shaft 40 extends through an arcuate slot 47 in the plate 42, as shown in Figure 6.

During normal operation, to compensate for the increase in diameter of the drum as the door is wound on to it, the cap screw moves relative to the plate 42 through the distance "x", which may be, for example, 12mm. When the door is closed and wind is blowing on the panel 15 to tend to unwind the panel from the drum, the panel may be permitted to unwind, against the action of the spring which maintains the panel in tension, until the cap screw abuts the end 48 of the slot. Further relative movement in that direction is then prevented and the bagging is restricted. When the sheet is wound in, even if the wind force on the panel is considerable, excessive bagging is prevented and the cap screw is either brought into engagement with the end 48, or maintained in engagement to provide a positive wind up drive for the drum.

The provision of the cap screw and socket which permit restricted relative rotational movement between the drum and drive shaft enables phenomenal operating speeds to be achieved, and the safe edge of the doorway may move at lm/s.

In order to remove a drum, for instance for maintenance, the bullet shaft 40 can be withdrawn from the socket in the shaft 44 by turning a threaded key 49. Thereafter the drum can be pivoted clear of the upper assembly and lifted out of the rotational bearing assembly at the bottom.

Attachment of the drum to the drive assembly is a reverse of that procedure.

As shown in Figures 1 and 7, the lower edge of each safe edge 17 is arranged to extend through a brush seal 49 into a guide channel 50.

Two annular brushes 51 (only one of which is shown) are secured to the safe edge 17 within the channel such that any dust or debris within the channel is swept to a downwardly recessed reservoir 52 each time the door is opened. The reservoir may be emptied when required. The wind bar may also extend into the channel and be provided with brushes if desired.

Referring to Figures 1, 8 and 9, the casing 60 of the driving mechanism can be seen to extend along the underside of the top edge of the doorway 12. The side casings 61 extend along the inner edge of each of the sides of the doorway 12. The casings 60 and 61 lie in a plane forward (in an inward to outward direction) of a loading dock 62 comprising an area raised typically to the height of the container base of an articulated lorry.

For the high wind force applications with which the present invention is concerned, wind damage may still occur, even with this system. The force exerted on rails 32, 36 by the cantilever of the wind on the door panels 10, 11 is likely to cause damage. Therefore, there is provided an additional circular bar 63 substantially parallel with bars 32, 36. The bar 63 is located about lm below the lower bar 32 and runs between the two side casings 61 and is secured to them at either end. The bar 63 lies in a plane behind the plane of the doorway 12, ie partly over the dock 62. The bar 63 is supported by a reinforcing rail 65 to which it is attached along its length by a plurality of mounts 66.

On the bar 63 is a free-running carriage 64 shown in more detail in Figure 9. The carriage 64 comprises, around the bar 63, a linear bearing 67 within a carriage body 68 comprising a substantially cuboidal casting. To one side of the body 68 is a grease spigot 59 in liquid communication with the interface between the bush 67 and the bar 63. The body 68 is fast to a boss 69 fast with the safe edge 17.

By supporting the safe edge 17 with a relatively rigid bar 63, reinforced by rail 65 the length of the cantilever is shortened by about 1m which provides enough of a reduction for the door panels 10, 11 to be able to withstand all predicted loads. It is noted that because the bar 63 is behind the plane of the doorway 12 it does not interfere with reversing vehicles even if they are higher than it because they will hit the dock 62 before the bar 63.

Referring to Figures 1, 8 and 10, the safe edge 17 includes two slots 85 from which project flexible plastic arms 86 which are about lm long. Inside the casings 61 the arms 86 are connected to motion sensors 87. The sensors 87 signal when the arms 86 contact something between the doors 10 and 11, and instruct the drive system to stop the doors 10 and 11 within the next 1 metre. Thus if a vehicle is unloading and the doors close, they will stop near the side of the vehicle preventing passage past the side of the vehicle in the doorway 12. This adds to the security for applications such as bonded warehouses.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims (22)

1. A door arrangement comprising a flexible door movable between a first position, in which the door extends at least partially over an opening and a second, retracted position, in which the flexible door comprises a relatively rigid support arranged to move with the door between the first and second positions and means to support the door, which support means is located intermediate the top and bottom of the opening.

2. An arrangement as claimed in Claim 1 including a drive assembly in the vicinity of the top of the door from moving the door between the first and second positions.

3. An arrangement as claimed in Claim 1 in which the drive assembly includes a further support means comprising a bar to which the relatively rigid support is coupled.

4. An arrangement as claimed in any preceding claim in which the door is a side opening door.

5. An arrangement as claimed in Claim 4 in which the door is a bi-parting door.

6. An arrangement as claimed in any preceding claim in which the support means is located such that the gap of the opening below the support means is greater than the gap of the opening above the support means.

7. An arrangement as claimed in any preceding claim in which the support means is coupled to the relatively rigid support.

8. An arrangement as claimed in Claim 7 in which the support means is connected to the relatively rigid support by a boss.

9. An arrangement as claimed in any preceding claim in which the support means comprises a bar.

10. A support means as claimed in Claim 9 in which the bar is part circular in cross-section.

11. An arrangement as claimed in any preceding claim in which the support means is reinforced by a rail.

12. An arrangement as claimed in Claim 11 in which the support means is connected at a plurality of locations along its length to the rail.

13. A support means as claimed in any preceding claim which is substantially horizontal.

14. A support means as claimed in Claim 3 or any preceding claim when dependent upon Claim 3 in which the support means is substantially parallel to the further support means.

15. An arrangement as claimed in any preceding claim in which the relatively rigid member includes sensor means for detecting the presence of an object in the path of the relatively rigid member as the door moves from its second to its first position.

16. An arrangement as claimed in Claim 15 in which, if an object is detected, means are provided for halting the door before it reaches the object.

17. An arrangement as claimed in Claim 16 in which the distance before the object that the door is halted is less than 30 cm.

18. An arrangement as claimed in any preceding claim in which the door has an outside and an inside relative to a structure such as a building and the support means is located on the inside of the door when the door is in the first position.

19. An arrangement as claimed in Claim 18 or any preceding claim when dependent upon Claim 11 in which the reinforcing rail is on the inside of the support means.

20. An arrangement as claimed in any preceding claim in which the flexible door is wound back on to a roller when it is retracted.

21. An arrangement as claimed in any preceding claim in which the support means is the lower support means of the door for the relatively rigid support.

22. A door arrangement substantially as herein described and as shown with reference to Figures 8 and 9 of the accompanying drawings.