AU603289B2 - Improved rolling door curtain - Google Patents

Description

60 3209 7^ f %J rTh' wa j COMMONWEALTH OF AUSTRALIA FORM PATENTS ACT 1952 COMPLETE 9 P E C I F I C A T T 0 N FOR OFFICE USE: Class Int.Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: 0 T Priority: ".elated Art: i his docu nc:t sAwa -1;io9 abd i cure it for s pliiitig, Name of Applicant: o Name of Applicant: WHITEHOUSE MANAGEMENT TECHNT'.iL SERVICES PTY. LTD.

Address of Applicant: 0 t I Actual Inventor: 12 Berrigan Street, Northmead, New South Wales, 2152, Australia.

Martin Harcourt Whitehouse .,i Address for Service: SHELSTON WATERS, 55 Clarence Street, Sydney Complete Specification for the Invention entitled: "IMPROVED ROLLING DOOR CURTAIN" The following statement is a full description of this invention, including the best method of performing it known to me/us:- 1 Complete of PI 7457 Filed on 25 March 1988

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011 ~IO 0 0 a0 0 o 'n 0~0 o 0 o 0 0 0300 0 0060 o o 00 00 oJ 0 0 60 0000 ee 0 00 00 0 0 0 o 0 0 0 0 00 00 0 f0 0 0a 00 4 0 0 0 00 The present invention relates to rolling doors of the type (hereinafter "the type hereinbefore described") having a curtain or door apron which slides vertically between opposed guides as the curtain winds on or off a horizontal drum located above the door aperture.

For reasons of strength, weight and economy, the door curtain is generally corrugated horizontally and this provides particular problems for the successful operation of the door.

Because of the general size of the openings that such doors are used on, it is normal to manufacture the corrugated curtain of the door in a series of sheets which are joined together by the well-known Pittsburgh lock seam or equivalent.

Doors of this type generally have a horizontally mounted drum which supports the curtain and is generally defined by a spaced pair of parallel end disc, mounted for rotation about a stationary horizontal axle. It will be appreciated that as the curtain winds progressively further onto the drum, the geometry of the resultant curtain spiral becomes complex.

It is also customary to employ a counterbalance spring for applying an opposing torque to the drum in order to balance the weight of the curtain. The spring is tensioned to its maximum extent when the curtain is fully unwound, with the door in its closed position. This would be expected since an operator would otherwise be required 2 9_ to lift the maximum weight of the curtain in order to move the door. Similarly, the counterbalance spring provides a minimum torque reaction when the door is fully open and the curtain wound to its maximum extent on the drum.

Unfortunately, the behaviour of the curtain, in terms of its interaction with the drum, is by no means linrar and it has been found empirically that the counterbalancing of the curtain is not uniform and satisfactory throughout its limits of moverr.-nt.

.0 The ideal door would have a constant traction effort o o, o othroughout its opening and closing so that the operator noon effort was at a minimum in all positions.

Further, it is common in doors of this type that they opr no are fitted with locking mechanisms mounted at approximately half the door height and a handle on the bottom edge. The n44r0 0 0 effect of transferring the weight of the locking mechanism 0 1 °00 from the front or balanced side of the curtain roll to the *o 0rear or counterbalanced side of the curtain roll as occurs during the opening and closing function, causes a marked ,0 variation in operating effort.

o 4 o. To reduce the variation in traction effort the drum wheel follows the shape of an Archimedean spiral.

Variations to the pure mathematical shape are created to minimise the described problems.

It is normal in such door structures that the topmost sheet of the door remains curved around the drums when the door is in the closed position. This allows the drums to be stabilised by additional fixings and obscures the 3 working mechanism of the door. This top sheet of the door requires considerable effort in maintaining its curved shape and it has been the practice to carry out additional operations on the sheet to make it take up a natural curve that fits the drums. Doors that have not had this curved process carried out, exhibit a tendency for the first top sheet to belly out or become barrel shaped, causing the first sheet to clash with the subsequert sheets.

Further it has been shown that when the valley of the corrugation contacts the plain drum wheel, that deformation in the valley occurs particularly during the stress of transport. This problem has been overcome by Soconstructing drum wheels with a matching corrugated shape 0 .0 (Prior Art Patent Application No. 84972/75 Whitehouse).

o0 0 According to a first aspect, the present invention 0 0 provides a corrugated curtain for use in rolling doors of 00 00 oo 0 the type hereinbefore described said curtain comprising a plurality of corrugated sheets joined together by a lock 00: seam or the like along each longitudinal edge thereof, an 420 uppermost sheet of said curtain, relative to the door opening, adapted to form the first layer when wrapped 0 4 4 S, around a door drum, said uppermost sheet having peaks and valleys respectively narrower and broader than the peaks and valleys of at least the next adjacent sheet forming said curtain such that the peaks of the corrugations of said uppermost sheet nest within the peaks of the next adjacent sheet of the curtain.

According to a second aspect the invention provides a rolling door formed using a curtain according to the first aspect.

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A preferred form of the invention shows a door that is constructed with a top sheet or first layer manufactured from a corrugated sheet, opposite in profile to the remaining sheets in the door opposite meaning that the valleys of the corrugations are broad and the peaks narrow the pitch of the corrugations on the sheet are so arranged that the peaks of the first sheet nestle or mesh with the broader peaks on the next layer of the door. The advantage of this arrangement is that for a door of a given oo 0 height and drum radius, the overall diameter of the rolled o oN up door is smaller.

0 For preference, the first sheet is pre-curved to 8~4 ~conform to the circumference of the door drum.

~a *1 o Further, the broad valleys contact the drum discs over a much larger area reducing the contact pressure preventing damage during transport. This then allows the Suse of a simple plain rim drum which can be made by simple manufacturing techniques. As this new top sheet 0 arrangement requires the first and second sheet to mesh, the likelihood of scuffing is reduced as there are no high i:¢ loads caused when one or more valleys (or troughs) misalign with the next layer. Further, the sheet being manufactured only as a topmost sheet in the door, allows its manufacture in a pre-curved form, eliminating subsequent operations on the door assembly to overcome the problems of paint scuffing.

i 5 J A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawing which shows an end elevation of a door roll according to the invention.

The drawing shows a drum 5 having a spiral configuration in cross-section and having a door curtain 6 wound thereon. The first layer of door curtain 6 comprises a first corrugated sheet 7 having broad valleys 8 in the corrugations and narrow peaks 9. The next sheet 10 has a o l0 normal corrugation with similarly sized peaks and valleys 01 m o 11 and 12 respectively. The first sheet 7 when wound on the drum 5 has its peaks nestled within the broader peaks of the second sheet giving a smaller diameter to the rolled Sup door. The edges of the corrugated curtain 6 are provided with resilient rubbing strips 13 which provide o smooth movement of the curtain 6 along the door tracks (not shown). This configuration further provides a broad area 4 of support on the drum for the door as shown at 'A' It will be appreciated by those skilled in the art that further embodiments and exemplifications of the invention are possible without departing from the spirit and scope of the invention described.

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Claims (2)

1. 4. A corrugated curtain for use in rolling doors substantially as hereinbefore described with reference to ori the accompanying drawing. A rolling door formed using a curtain according to any one of the preceding claims. Dated this 6th Day of AUGUST, 1990 WHITEHOUSE MANAGEMENT TECHNICAL SERVICES PTY. LTD. Attorney: PETER HEATHCOTE Fellow Institute of Patent Attorneys of Australia of SHELSTON WATERS
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