GB2335940A

GB2335940A - Roller shutter with cushioning/restraining means

Info

Publication number: GB2335940A
Application number: GB9907206A
Authority: GB
Inventors: Andrew Dootston
Original assignee: Security Window Shutters Ltd
Current assignee: Security Window Shutters Ltd
Priority date: 1998-04-02
Filing date: 1999-03-30
Publication date: 1999-10-06
Also published as: GB9907206D0

Abstract

A roller shutter of the type comprising a plurality of elongate members/slats (3) which are hingedly connected to one another along opposite edges by mutually engageable formations formed integrally therewith to define a slatted door or curtain (1) has secured to at least one side cushioning or restraining elements. The restraining means may comprise a strip of flexible material (9) fixedly secured to the elongate members bridging the joints between adjacent slats, with the purpose of reducing longitudinal movement of the slats. The flexible material may also have cushioning or draft sealing properties so as to reduce noise and weather problems respectively. Also disclosed are methods of centralising the roller shutter by the use of additional spaced apart rollers with frusto-conical portions (51), and means for inhibiting the unauthorised manual raising of the shutter by the limited articulation of jointed connecting elements (30).

Description

2335940 1 Title: Roller Shutter The present invention relates to roller

shutters and especially to roller shutter doors but without limitation to same.

Roller shutter doors are well known and comprise a plurality of elongate members which have opposite edge formations which permit interconnection with one another in a manner which allows limited hinged movement therebetween, at least sufficient to permit the door curtain to be rolled up. A known construction of slatted shutter utilises slats whose edge formations allow thern to be engaged by a relative longitudinal sliding movement. Restraining the longitudinal movement after assembly has dictated the use of end locks/caps which bridge the junction between adjacent slats. These end locks/caps have to be secured to each of the slats to ensure longitudinal restraint. The installation of these end locks/caps is labour intensive and therefore adds to the cost of production. One aspect of the invention aims to provide an advantageous alternative.

The position of the door when deployed is defined between oppositely disposed upright grooves or guide rails in which the opposite ends of the slats are received. The stats form a door sheet/curtain and it is attached to an axle which is mounted above the head of the door. Its axis has to be offset from the plane of the door by an amount sufficient to accommodate the diameter of the door curtain when rolled up. The grooves provide a longitudinal restraint or centralising function. If the means which ensure relative longitudinal restraint of the slats should fail, the slats can move out of alipment. This can result in increased wear and noise in operation, including damage to the grooves, and ultimately jamming of the door. Another aspect of the invention 2 aims to provide a solution. Another aim of the invention is to provide a roller shutter construction which is secured more positively in its lowered position than with prior art designs.

Accordingly, a first aspect of the invention provides a roller shutter door of the type comprising a plurality of elongate members/slats which are hingedly connected to one another along opposite edges by mutually engageable formations formed integrally therewith and wherein relative longitudinal movement of the elongate members is restrained by a restraining means comprising one or more strips of flexible material fixedly secured to the elongate members/slats.

The strip bridges the joint between at least two elongate members. The material of the strip may be a flexible tape of plastics or other suitable material. More preferably it is a woven material. More particularly, the strip comprises a continuous length of tape, webbing or the like extending across all the slats forming the door and is preferably secured to each one. Conveniently an adhesive is used to secure the strip of material to the slats. More conveniently, the strip incorporates an adhesive layer. The adhesive layer is covered by a removable backing strip prior to application to the slats. A rivet provides an alternate means of fixig the material to each slat as it can have a head of shallow depth and is readily fixed. One or more rivets may be used in addition to the adhesive where additional security of fixing is required. The use of the flexible strip of material is advantageous as it speeds up the assembly procedure. It also serves to make the assembly more of a rigid sheet. This also ensures that it coils tidily. It also has the effect of fixing the slat spacing. This is advantageous as it ensures alignment of any locking mechanism(s) carried by the door with the intended aperture(s) in the guide rail(s) which may not always be the case when the pivot point between slats allows 3 variations in spacing of the slats. The provision of the strip avoids rolling metal on metal. Hence noise is reduced and the potential for abrasion either of the metal itself and/or of any decorative finish applied thereto. Thus maintenance is reduced.

The preferred slats are slightly curved when viewed in cross-section. This minimises the diameter on rolling up. The concave portion forms the inside of the door curtain. The opposite ends of the slats are received in a respective elongate groove. It is preferred to provide two lengths of material with one positioned adjacent each end of the slat to coincide with the position of the groove. It is particularly advantageous if the exposed surface of the flexible material has a plurality of flexible bristles or hairs, usually of a synthetic nature, whereby the material functions as a draft seal and also a noise reduction device by preventing rattling in the groove and more especially cushioning the slats as they are rolled up or unrolled. The provision of a material with an upstanding pile ensures adequate sealing between the concave side of the slats and the groove irrespective of the different spacing across the width thereof. A low friction material is preferred to ease sliding movement in the groove during raismig and lowering of the door. Such a strip of material may be fitted to one or both sides of the slats.

Where it is fitted to the outside it necessarily incorporates some elasticity to accommodate rolling up of the slats.

The use of the strip has advantages in respect of reducing noise and/or draft sealing and may be used with shutters in which other means such as the aforementioned end caps are used to provide restraint against relative longitudinal movement of the elongate members.

Accordingly, another aspect of the invention provides a roller shutter door of the type comprising a plurality of elongate members/slats which are hingedly connected to 4 one another along opposite edges by mutually engageable formations formed integrally therewith and further comprising one or more strips of flexible material secured to the elongate member slats and extending generally perpendicular to the elongate direction of the slats.

The strips act as a cushioning and/or noise reduction and/or draft reducing means. Relative longitudinal restraint of the elongate members/slats may by means of a plurality of end locks/caps secured to the slats in a position to bridge the junction between adjacent slats.

The aforedescribed slats may be hollow section. They may be extrusions of say aluminium or plastics, and they may be infilled with insulation material. Preferably they are roll formed foam filled aluminium but in some applications other material rnay be used, e.g. steel (suitably protected) and insulation may not be required.

Another aspect of the invention provides a roller shutter door assembly comprismig a plurality of elongate slats hingedly connected to form a horizontally slatted door sheet/curtain connected to an axle which is rotatable for raisina and lowering of the door sheet/curtain, a pair of spaced guide rails to receive the opposite ends of the slats to define the lateral extremities of the door, and a pair of spaced apart rollers which contact opposite ends of the elongate slats, the rollers being disposed between the axle and the start of the guide rails and wherein the rollers include a frusto-conical portion which serves to centralise the slats.

The provision of the centralising rollers ensures that if the aforementioned end lockincr caps should fall, or if the aforementioned tape should fail, the slats will be held in alignment by the action of the rollers. They also serve to keep the curtain square durmig coiling and uncoilmic, and avoid extra friction in the guides and reduce noise by c 1 avoiding unwanted end contact with the guides.

Another aspect of the invention provides a roller shutter door assembly comprising a plurality of elongate slats hingedly connected to form a horizontal slatted door sheet/curtain which is connected directly to an axle by jointed link elements which have limited articulation, the axle being driven by an electric motor, a pair of spaced guides into which the opposite ends of the slats are entrarit for location purposes, and wherein on full deployment of the slats the jointed link elements between the guides and the axle being un-restrained are caused to articulate into a position which when the motor is locked against rotation prevents upward movement of the door sheet by the application of an upward force to the door sheet.

More particularly, the jointed elements are caused to adopt what might be termed an over centre position, i.e. deflected from the un-restrained path of the slats, into a lock up position. The jointed element may comprise the slats themselves or parts thereof For example - short lengths of the slats may be provided at discrete locations along the length of the elongate slats - say 3 - one to each end and one in the middle.

Preferably there are a minimum of three elements to each connection. It is preferred that the limited articulation of the link elements, is the same as the limited angular movement which is possible between the elongate slats so that the same extruded shape can be employed. In some circumstances an increased articulation may be desirable for the link elements. The number of links in each set may be used to adjust the height of the door. The use of links of short length is advantageous as their limited length allows thern to be inserted when the door is in position, there being only limited space to the side of the door above the guides.

The present invention will now be described further by way of example only 6 with reference to the accompanying drawings; in which: - Figure 1 is an exploded perspective view from the inside of a roller shutter door assembly, Figure 2 is a perspective view of a centralising roller of the door assembly of Figure 1, and Figure 3 is a schematic view of the upper end of a roller shutter door.

Referring firstly to Figure 1, a roller shutter door curtain is shown at 1 and comprises a plurality of elongate slats 3 whose opposite edges are configured for mutual co-operating engagement in a hinged manner with an adjacent slat. For this purpose each slat has a longitudinally extending groove 5 formed along one edge and a complimentary protrusion 7 formed along its opposite edge. The arrangement allows adjacent slats to be brought into engagement by a longitudinal sliding movement. Once the slats have been so engaged, they are maintained in longitudinal alignment with one another by the application of two strips of fabric 9 to the slats. The strips are positioned immediately adjacent the ends of the slats. In the illustration they are secured to the slats by a combination of adhesive and by rivets 11. The preferred strip of fabric has a pile to it and is conveniently referred to as a brush strip. Each strip is a continuous stnip.

In the illustrated embodiment the slats 3 with the exception of a bottom slat 13 are roll formed foam filled aluminium. They are curved in section with the inside being concave and the outside convex. Where rivets are used to connect the brush strip to the inside surface of the slats are not visible to the outside.

The opposite ends of the slats are received in guide rails 19. There are two guide rails and they have open grooves which face one another. The outer limb 21 of the grooves is provided with a resilient seal strip 23, conveniently made of plastics. The 7 brash strip 9 co-operates with an inner limb 25. A low friction material is preferred for the brush strip and/or the seal strip 23. The presence of these strips cushions the movement of the c in the grooves making them quieter in use than shutters where these strips are omitted. The brush strip 9 fills the gap between the inside surface of the slats and the de rail and thereby improves insulation and enhances draft proofing gui c, Furthermore, on rolling up of the door c the flexible strips of fabric engage the outside surface of the slats where they overlay the previous wrap of slats. Thus the fabric acts as a cushioning element and reduces the noises emanating from the door during rolling and unrolling.

The roller shutter door assembly further comprises an axle 31 which has a hexagonal peripheral shape in the illustrated embodiment and its opposite ends are received in mounting s 33 of securing brackets 35. An electric motor 37 is connected to the axle and controls rotation of same. Lever arm 39 is part of a manual override assembly which is not described in flather detail.

The axle 31 carries connecting strips 41 which have a groove 45 adapted to receive a male connecting element 47 of connecting links 30. To all intents and purposes the connecting links 30 comprise short lengths of the slats 3 and their male and female connecting parts correspond. Fulllength slats could be used, but since these connecting links are above the threshold of the door opening they do not need to be full length and costs can be saved by the use of short lengths. In the illustrated embodiment, two sets of spaced apart connecting links 30 are used. The number used may vary depending on the width of the door and/or the length of each set. In the illustrated embodiment, each set has three elements. The number of elements in each set can be changed to tailor the door length to a particular opening. Furthermore, short lengths are 8 advantageous because they can be installed when the door is in place where this is necessary to adjust the overall height of the door curtain to suit the opening. The link elements connect the uppermost full-length elongate slat of the door curtain to the axle 31.

The securing brackets 3 5 each have j ournalled thereon a respective roller 5 1 and shown fin-ther detail in Figure 2. The roller 51 is journalled for rotation on an axle 53 it abuts a flange (not shown) and is retained on the axle by a washer 55 and split pin 57.

The roller has a plain cylindrical portion 59 and a frusto-conical portion 6 1. The securing brackets 35 have a downwardly depending leg 63 which is arranged to be received in a longitudinal box section 65 of the guide rail 19. The rollers are positioned to engage the opposite ends of the elongate slats. The length of the slats is such that they will rest on the cylindrical portions.

The position at which the frusto-conical portion 61 emerges from the cylindrical portion 59 is such that the frusto-conical position acts to urge the slats to a centralised position. This ensures that if the tape comes adrift the slats will be centralised and the shutter will continue to operate.

Referring now to Figure 3. Here the securmig bracket 35 is illustrated and the relative position of the axle 31 and the upper end of the guide rail 19. The uppermost elongate slat 3 of the door curtain is shown and the three connecting links 30. The door curtain is shown in its fully deployed position and it will be seen that the joints between the connecting links have in effect gone over centre, compared with the angle they will adopt when rolled onto the axle. With the electric drive motor locked against rotation, any upward force on the door curtain, as represented by arrow F, will keep the locking elements in this over centre position. Le. there will be a reaction which urges them 'm 9 the direction of arrow R. As flirther articulation is limited by the operation of abutment surfaces of the joints, upward movement of the curtain is resisted.

Claims

1. A roller shutter of the type comprising a plurality of elongate members/slats which are hingedly connected to one another along opposite edges by mutually engageable formations formed integrally therewith and further comprising one or more cushioning elements secured to one face of the elongate member/slats.

2. A roller shutter as claimed in claim 1 in which the cushioning element comprises a strip of flexible material which bridges the joint between at least two elongate members A roller shutter of the type comprising a plurality of elongate members/slats which are hingedly connected to one another along opposite edges by mutually engageable formations formed integrally therewith and wherein relative longitudinal movement of the elon-ate members is restrained by a restraining means comprising one or more strips of flexible material fixedly secured to the elongate members/slats and bridgiulg the joffit between at least two elongate members.

A roller shutter as claimed in claim 2 or 3 in which each strip comprises a continuous length of tape extending across a plurality of the slats forming the shutter.

5. A roller shutter as claimed in claim 4 in which the strip extends generally perpendicular to the elongate direction of the slats.

6. A roller shutter as claimed in claim 4 in which the strip extends across all the slats forming the shutter.

7. A roller shutter as claimed in anyone of the preceding claims in which the strips of flexible material or the cushioning. elements as the case may be are secured to each elongate member/slat.

11 8. A roller shutter as claimed in claim 7 in which the strips or elements are secured using adhesive.

9. A roller shutter as claimed in claim 7 or 8 in which the strips or elements incorporate a self-adhesive layer.

10. A roller shutter as claimed in claims 7, 8 or 9 in which the strips or elements are secured by riveting.

11 - A roller shutter as claimed in 4 or anyone of claims 5 to 10 when appended to claim 4 in which there are at least two strips disposed at spaced locations on the shutter.

12. A roller shutter as claimed in claim 11 in which there are two lengths of tape with one positioned adjacent each end of the elongate member/slats.

13. A roller shutter as claimed in anyone of the preceding claims in which the exposed surface of the strips or elements has a plurality of flexible bristles or hairs.

14. A roller shutter as claimed in anyone of the preceding claims in which the strip or elements have a low friction surface.

15. A roller shutter as claimed in anyone of the preceding claims in which tle strips or elements are applied to the interior and/or exterior surface of the elongate members/slats relative to the direction of rolling up.

16. A roller shutter as claimed in anyone of the preceding claims in which the plurality of hingedly connected elongate slats form a slatted sheet/curtain connected to an axle which is rotatable for raising and lowering of the sheet/curtain, a pair of spaced guide rails to receive the opposite ends of the slats, and a pair of spaced apart rollers whch contact opposite ends of the elongate slats, the rollers being disposed between the axle and the start of the guide rails and wherein the rollers include a fiwto-conical portion which serves to centralise the slat.

12 A roller shutter assembly comprising a plurality of elongate slats hingedly connected to form a horizontally slatted door sheet/curtain connected to an axle which is rotatable for raising and lowering of the door sheet/curtain, a pair of spaced guide rails to receive the opposite ends of the slats to define the lateral extremities of the door, and a pair of spaced apart rollers which contact opposite ends of the elongate slats, the rollers being disposed between the axle and the start of the guide rails and wherein the rollers include a frustoconical portion which serves to centralise the slats.

18. A roller shutter assembly comprising a plurality of elongate slats hingedly cormected to form a horizontal slatted door sheet/curtaffi which is connected directly to an axle by jointed link elements which have limited articulation, the axle being driven by a motor, a pair of spaced guides into which the opposite ends of the slats are entrant for location purposes, and wherein on full deployment of the slats the jointed link elements between the guides and the axle being un-restrained are caused to articulate into a position which, when the motor is locked against rotation, prevents upward movement of the door sheet by the application of an upward force to the door sheet.

19. A roller shutter assembly as claimed in claim 18 in which the jointed elements are caused to adopt a position, deflected from the un-restrained path of the slats, corresponding to a lock up position.

20. A roller shutter assembly as claimed in claim 18 or 19 in which the jointed element comprise the slats themselves or parts thereof 2 1. A roller shutter assembly as claimed in claim 20 in which the jointed elements comprise short lengths of the slats provided at discrete locations along the length of the elongate slats.

13 22. A roller shutter assembly as claimed in anyone of claims 18 to 21 comprising at least three elements to each connection.

23. A roller shutter as claimed in anyone of claims 18 to 22 in which the limited articulation of the link elements is the same as the limited angular movement which is possible between the elongate slats so that the same extruded shape can be employed.

24. A roller shutter as claimed in anyone of claims 18 to 23 in which the number of links Mi each connection is used to adjust the height of the door.

25. A roller shutter constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.