AU2003204532B2 - Improvements in retractable sunscreens - Google Patents

Description

Ot fr n -ra-i' 0U/ O/ 3tI 3:31 J. b4qJJtr// MCKECHNIE PAGE 03 1 TITLE: IMPROVEMENTS IN RETRACTABLE SUNSCREENS TECHNICAL FIELD The present invention relates to improvements in the retractable sunscreen disclosed in Australian Patent Application No 97220/01.

The parent patent relates to a retractable sunscreen which includes two parallel tracks; a plurality of parallel rods the ends of which are arranged to slide in the tracks; and a length of flexible material one end of which is secured at one end of the rails and the remainder of which is supported at spaced intervals along its length by the rods, which are secured to the flexible material such that movement of the rods along the rails expands or contracts the screened area provided by the sunscreen.

BACKGROUND ART A wide variety of different designs of sunscreen have been proposed over the years.

Typical designs are shown in U.S. Patent No. 5,451,445, which discloses a netting screen; U.S. Patent No. 6.042,153 which discloses a screen made of lightweight rigid corrugated plastic sheet supported between two parallel pipes; and U.S. Patent No.

5,794,679, which discloses a sunscreen consisting of three parallel rails with spaced rods moving along tracks mounted on the rails and flexible sheets supported upon the rods.

Typically, prior art screens can be secured in the fully extended position and/or in the fully contracted position, but not at any intermediate position. This has the drawback of somewhat limiting the use of the screen, since either the full area must be screened or the screen must be stowed away. In practice, it often is desirable to screen only part of the screened area.

DISCLOSURE OF INVENTION An object of the present invention is to provide a retractable sunscreen which overcomes the above described problem.

The present invention provides a retractable sunscreen which includes: a pair of parallel tracks adapted to engage the ends of each of a plurality of parallel rods, the length of each rod being substantially perpendicular to the lengths of the tracks; a portion of flexible material one end of which is secured at one end of said tracks and the remainder of which is supported at spaced intervals along its length by said rods, COMS ID No: SMBI-00283258 Received by IP Australia: Time 11:32 Date 2003-06-05 05/09/2003 13:31 +6433844779 KERIRAE0 MCKECHNIE PAGE: 0 4 2 which are attached to the flexible material such that movement of the rods along the tracks expands or contracts the screened area provided by the sunscreen; the other end of the flexible materiall being secured to a front rod which is parallel to maid plurality of rods arid which is provided with a fail-safe braking means arranged to releamably secure the front rod relative to the tracks at any point along the length of the tracks whenever said front rod is released.

Preferably, each said track is provided by a rail which includes a pair of spaced parallel sidewalls extending parallel to the length of the rail and defining a channel there between, one of said sidewalls being formed with a slot extending parallel Io the length of the rail, to provide access to the channel.

Preferably, each end of each parallel rod carries a freely rotatable roller adapted to extend into the slot in the adjacent sidewall and to roll along the lower edge of the slot; and each end of each parallel rod also carries a freely rotatable wheel the plane of which is parallel to the plane of the slot and the diameter of which is greater than the width of the slot, each said wheel being located within the slot.

A known problem with existing screen designs is that the flexible material of which the screen Is made tends to stretch and contract due to changes in temperature and In humidity. This Is a particular problem for a fully exposed out door screen, which may become very wet indeed when it rains, When the flexible material stretches. it tends to sag and look untidy; more Importantly, a sagging screen can catch the wind and be torn. Equally, if a screen is held taut when it is wet, it may tear when Rt dries and the material contracts.

To overcome this problem, in a preferred embodiment of the present invention, one end of the flexible material is resiliently secured at said one end of said tracks.

Preferably, one end of the flexible material is secured to a crossbar extending parallel to said rods, each end of the crossbar being secured to one of the tracks by mneans of a movable bracket; each end of the crossbar being resiliently connected to the corresponding bracket.

Preferably, the leading edge of the front rod has a pull bar secured thereto, extending parallel to the front rod and spaced outwards from ft, clear of the flexible material.

Preferably also, the front rod is engaged with the corresponding track at each end, and each end of the front rod is provided with fall-safe braking means in the form of a pair COMS ID No: SMBI-00283258 Received by IP Australia: Time 11:32 Date 2003-05-05 r/rrr 0fnn -i tJO/ l a ,i tb4-s44tfE MKECHNIE PAGE 3 of spaced brake pads arranged to engage the edges of the corresponding slot in a braking relationship so as to releasably secure the front rod relative to the tracks unless the pull bar and the front rod are lifted relative to the tracks by a predetermined amount.

BRIEF DESCRIPTION OF DRAWINGS By way of example only, a preferred embodiment of the present invention is described in detail, with reference to the accompanying drawings, in which:- Figure 1 is a plan view of a retractable sunscreen in accordance with the present invention; Figure 2 is a section on line II II of Figure 1; Figure 3 is an end view in the direction of arrow Ii of Figure 1; Figure 4 is a side view of Figure 3; Figure 5 is a side view in the direction of arrow V of Figure 1; Figure 6 is a longitudinal section on line VI VI of Figure 1; and Figure 7 is a section on line VII VII of Figure 6, BEST MODE FOR CARRYING OUT THE INVENTION Referring to the drawings, a retractable sunscreen 2 in accordance with the present invention consists of a pair of parallel rails 3,4 which support a plurality of spaced rods secured to a flexible cover 6. The flexible cover 6 may be made of any of a range of suitable materials, e.g. canvas, nylon, sheet plastics material.

The crossbars 7,7a need not be present:- the outer crossbar 7a may be preferred to give the screen a "finished" appearance. However, the crossbars 7,7a are useful for maintaining the rails 3,4 parallel when the screen is first being erected, and may be removed when the screen has been completed. The parallel rails 3,4 may be supported in any manner suitable for their length and weight, e.g. by securing their inner ends 3a,4a, or both ends, to a suitable support such as a wall. Alternatively, or additionally, each rail 3,4 may be supported along its length by securing each rail to a parallel support such as a pergola rail at intervals or continuously along its length.

Each of the rails 3,4 has a cross-section as shown in Figure 3, and provides a pair of parallel sidewalls 8,9, with the inner sidewall 9 formed with a slot 10 to provide access into the channel 11 in the interior of the rail. The top 12 and bottom 13 of the rail each is formed with a channel 14,15, access to which Is given by a slot 16,17. The channels 14,15 may be used for a number of purposes:- COMS ID No: SMBI-00283258 Received by IP Australia: Time (H:m)11:32 Date 2003-06-05 05/06/2083 13:31 +6433844779

MCKECHNIE

PAGE 06 4 1) as tracks for lighting or similar components; 2) to receive connector plates used to join adjacent sections of rail together; 3) to receive fixing plates for attaching the cross bars 7,7a; 4) to receive fixing plates for securing the rails 3.4 to support structures.

At least the lower edge of each slot 10 is covered with a plastics wear strip 18 to act as a cushioning, noise reducing surface. Preferably, both edges are covered.

The rods 5 extend through pockets 19 (Figure 2) sewn in the cover 6. Each rod o1 extends between the rails 3,4, substantially perpendicular to the length of the rails.

Each rod 5 comprises a straight length of tube with a roller 20 and a wheel 21 secured to each end. Each roller 20 and wheel 21 is freely rotatable, with its axis of rotation parallel to the longitudinal axis of the rod 5. The plane of each wheel 21 is perpendicular to the said axis of rotation. The length of each rod 5 is such that each roller 20 rests on the lower edge of the slot 10 of the adjacent rail 3,4, and each wheel 21 lies within the channel 11, with plenty of 'play', to avoid jamming in use.. Thus, when the rods 5 are moved along the rails 3,4, they roll on the rollers 20 and the wheels 21 keep the rods 5 correctly aligned in the channels II.

Preferably the rollers 20 and wheels 21 are made of rubber or plastics, so that they move quietly on the rails.

The inner end of the cover 6, the end nearest to the wall or other structure supporting the rails 3,4) is secured to the rails by means of a crossbar 22 (Fig. 3 and 4) which is secured between the rails 3,4 perpendicular to the length of the rails, adjacent the inner ends of the rails. The crossbar 22 is secured to the rails 3.4 by means of a pair of brackets 23 each of which is releasably secured by cap-screws 25 in a slot 24 formed in the base of the channel 11 parallel to the slot 17. The position of each bracket 23 along the corresponding rail 3,4 can be adjusted as necessary by slacking off the cap-screws 25, moving the bracket to the desired position and retightening the screws.

Each end of the crossbar 22 is secured to the upright portion of the corresponding bracket 23 by a bolt 26. A coil spring 27 is mounted upon each bolt 26 between the bracket 23 and a washer 28 secured adjacent the end 29 of the bolt. The coil springs 27 give a degree of resilience to the cover 6 and allow it to be held taut in the fully closed position without risk of tearing if the cover contracts slightly due to the COMS ID No: SMBI-00283258 Received by IP Australia: Time 11:32 Date 2003-06-05 05/06/2003 13:31 +6433844779 MCKECHNIE PAGE 07 fabric drying). The springs 27 also allow the fully closed cover 6 to be held taut, giving a better appearance. The amount of resilience given by the coil springs 27 can be adjusted by adjusting the position of the brackets 23.

The outer end of the cover 6 is provided with a pull bar 30 which is rigidly secured to the front rod 5a, parallel to the length of the rod. The cover is moved by grasping the pull bar 30. raising it slightly to release the brakes 31 (as hereinafter described) and moving the pull bar in the desired direction. The pull bar may be grasped manually or with a suitable tool.

One brake 31 is secured to each end of the front rod 5a:- one brake is engaged with the rail 3 and the other with the rail 4. One of the brakes 31 is shown in detail in Figures 5 7. Each brake 31 comprises a plate 32. one end of which is rigidly secured to the adjacent end of the rod 5a, and the other end of which extends In a plane perpendicular to the length of the rod 5a and parallel to the length of the adjacent rail 3, opposite to the slot 10 in the rail.

The plate 32 supports two rollers 33,34 and two brake pads 35,36; the axles 37.38 of the rollers 33,34 and the support pins 39,40 of the pads 35.36 all are parallel and perpendicular to the plane of the plate 32. The rollers 33,34 both rotate freely on their axles; the outer diameter of the roller 33 is the same as the diameter of the rollers upon which the other rods 5 travel. The outer diameter of the roller 34 is considerably smaller than that of the roller 33.

The roller 33 is located adjacent the end of the rod 5a, close to the rear end of the plate 32. The roller 34 is located at the opposite end of the plate 32. The axles 37,38 of the two rollers both lie on the centre line of the plate 32.

A wheel 21a also is secured to each end of the rod 5a, and lies within the channel 11 with the plane of the wheel across the width of the channel, to keep the rod 5a correctly aligned with the channel.

The brake pads 35,36 are located on opposite sides of the roller 33, with the brake pad 36 adjacent the upper edge of the plate 32 and the brake pad 35 adjacent the lower edge of the plate. Each brake pad 35,38 is surfaced with a high fdriction material.

The above described brakes operate as follows:- when the pull bar 30 is released, the COMS ID No: SMBI-00283258 Received by IP Australia: Time (H:rn) 11:32 Date 2003-06-05 tinf tobI L Ujtj ±.i:zt bq64&4477 MUKEUHNLE PAGE 08 a weight of the pull bar moves the pull bar 30, the rod and both of the brakes 31, in the direction of Arrow B (Figure 7) and the brakes 31 are as shown in Figure 7, I.e. with the brake pad 36 pressed against the upper edge 10 a of the slot 10, and the brake pad 35 pressed against the lower edge 1lOb of the slot 10. The pressure of the brake a pads against the edges of the slot effectiveiy brakes the rod 5a and prevents the rod from slidi ng either forwards or backwards along the rails 3A4.

To release the brakes 31, the pull bar 30 is simply moved upwards in the direction of Arrow C (Figure 7) until the small forward roller 34 contacts the upper edge 1 0. of the ic slot 10; in this position, the brake pads 35 and 30 are out of contact with the edges of the slot and the pull bar 30 and rod 58 can be moved freely in either direction.

The brakes 31 are a 'fail-safe" design:- as soon as the pull bar 30 is released, the brakes 31 ae applied automnaticaly.

16 When the cover 8 has been fully extended, i.e. the screen covers its maximum extent, the cover 6 can be locked in that position simply by lifting the pull bar 30 slightly and pullng the cover 6 against the bias of the springs 27 until the cover is taut and the small forward rollers 34 on each side of the rod 5a lie in front of the vertical bolts secured to the rails 3,4. In the locked position, each roller 34 Dies in the position shown In broken lines in Figure 7. The cover 6 can be released from this locked position by lifting the pull bar 30 to lift the rollers 34 over the bolts The cover 6 also Is provided with moans for securing the cover in the fully contracted position; any of a range of suitable known means may be used, e.g. elastic straps securing the cover 6 and the associated rods 5,5a, to the ends of the rails, 3,4, or to a suitable portion of the supporting wall or other structure.

The sunscreen has been described in terms of a sunscreen which Is extended outwards from a wall or sinmilar supporting structure, but it will be appreciated that the sunscreen of the present invention could be extended in the opposite direction, i.e.

inwards towards the wall or other supporting structure or could be arranged to extend with the length of the screen parallel to the plane of the supporting wall, in. with the rails 3,4 extending parallel to the length of the wall.

COMS ID No: SMBI-00283258 Received by IP Australia: Time 11:32 Date 2003-06-05

Claims (6)

1. A retractable sunscreen which includes: a pair of parallel tracks adapted to engage the ends of each of a plurality of parallel rods, the length of each rod being substantially perpendicular to the lengths of the tracks; a portion of 6 flexible material one end of which is secured at one end of said tracks and the remainder of which is supported at spaced intervals along its length by said rods, which are attached to the flexible material such that movement of the rods along the tracks expands or contracts the screened area provided by the sunscreen; the other end of the flexible material being secured to a front rod which is parallel to said plurality of rods and which is provided with a fail-safe braking means arranged to releasably secure the front rod relative to the tracks at any point along the length of the tracks whenever said front rod is released.

2. The sunscreen as claimed In claim 1, wherein each said track is provided by a Is rail which includes a pair of spaced parallel sidewalls extending parallel to the length of the rail and defining a channel there between, one of said sidewalls being formed with a slot extending parallel to the length of the rail, to provide access to the channel.

3. The sunscreen as claimed In claim 2, wherein each rail also includes top and bottom surface each formed with a channel extending parallel to the length of the rail.

4. The sunscreen as claimed in claim 2 or claim 3, wherein each end of each parallel rod carries a freely rotatable roller adapted to extend into the slot in the adjacent sidewall and to roll along the lower edge of said slot. The sunscreen as claimed in claim 4, wherein each end of each parallel rod also carries a freely rotatable wheel the plane of which is parallel to the plane of the slot and the diameter of which is greater than the width of the slot, each said wheel being located within the slot.

8. The sunscreen as claimed in any one of the preceding claims, wherein said one end of the flexible material is resiliently secured at said one end of said tracks. 7. The sunscreen as claimed in claim 6, wherein said one end of the flexible material Is secured to a crossbar extending parallel to said rods, each end of the crossbar being secured to one of the tracks by means of a movable bracket; COMS ID No: SMBI-00283258 Received by IP Australia: Time 11:32 Date 2003-06-05 05/06/2003 *1 -01 CAo k '~Rr t 'nnIAr, MI'UKLt;HNIE PAGE 8 each end of the crossbar being resiliently connected to the corresponding bracket. 8. The sunscreen as claimed in any one of the preceding claims, wherein said front rod is engaged with the corresponding track at each end thereof, and each end of said front rod is provided with said fail safe braking means.

9. The sunscreen as claimed in claim 8, wherein the edge of the front rod furthest from said one end of said tracks has a pull bar secured thereto, the pull bar extending parallel to said front rod and spaced outwards therefrom to extend clear of said flexible material. The sunscreen as claimed in claim 9, wherein each braking means comprises a pair of spaced brake pads arranged to engage the edges of the corresponding slot in a braking relationship so as to releasably secure the front rod relative to the tracks unless the pull bar and the front rod are lifted relative to the tracks by a predetermined amount. 11, The sunscreen as claimed in claim 9 or claim 10, further including locking 0means mounted on each track, said locking means being adapted to releasably lock the sunscreen in the fully extended position. COMS ID No: SMBI-00283258 Received by IP Australia: Time 11:32 Date 2003-06-05