GB2211540A

GB2211540A - Latch for blind

Info

Publication number: GB2211540A
Application number: GB8720178A
Authority: GB
Inventors: Roy Raymond Lontho
Original assignee: Hunter Douglas Industries BV
Current assignee: Hunter Douglas Industries BV
Priority date: 1987-08-27
Filing date: 1987-08-27
Publication date: 1989-07-05
Also published as: EP0305081A2; GB8720178D0; DE3865598D1; EP0305081B1; ES2025781T3; EP0305081A3

Description

2211540 A LATCH ASSEMBLY FOR A RETRACTABLE BLIND OR SCREEN The present

invention relates to a latch assembly for a retractable screen or blind.

One form of such blind, particularly an insect blind. or an energy saving blind, includes a spring-loaded roller, blind or screen material wound on the roller, with guides along each edge to constrain the edges of the blind or screen material to prevent them from lifting from the plane of the blind or screen, and an end rail which is used to open and close the blind. A latch assembly is usually provided at each end of the end rail to lock the blind or screen in the required position.

Although the present invention is not exclusively concerned with such a blind or screen, it is concerned with the latch assembly for any form of retractable blind or screen, particularly for a blind or screen of this type.

Such blinds or screens may easily be drawn to the desired position and usually the latch at each end will readily engage with a latching plate on the door or on the window frame to lock the frame in the desired position.

However, it is relatively difficult to disengage the two latches simultaneously to release the blind so as it may go back towards its retracted position. This is particularly so where the blind has a considerable width. While blinds are normally considered to be raised and loweredr that it with the axis of the roller horizontal, it is quite common to have the axis vertical particularly when the screen or blind is used on a door or doorway. It will be appreciated that the two latches in such circumstances may be as much as two metres apart which makes their actuation extremely difficult.

It is now proposed. according to the present invention, to provide a latch assembly for a retractable blind or screen, to releasably lock the blind or screen in a required position. said assembly comprising a first part attachable to or integral with a movable end bar of the 1 1 k blind or screen, to move with the end bar and a second part locatable in a stationary position and engageable with or disengageable from the first part by operating the end bar, the first part of the assembly including a support and a laterally extending locking member mounted on said supportr the second part of the assembly including an inclined ramp, a generally rearwardly extending member behind one end part of the rampt said member having a locking surface engageable by said locking member to hold said blind or screen in a required position against retractionr a return passage communicating with the space occupied by said locking member when it is engaged against said locking surface and through which said locking member may pass. to allow the blind or screen to return towards its retracted position and a stop between said space and said return passage, said stop preventing said locking member passing accidentally into said return passage, but allowing said locking member to pass when the blind or screen is moved away from its retracted position so that the locking member is moved away from the locking surface.

Such a latch assembly can be made relatively simply and cheaply and yet can enable very easy operation with one hand. In order to lock the blinds in a required position, the blind is moved away from its roller an amount which is slightly greater than that of the desired position. The locking member slides along the inclined ramp and can then be moved, or can be arranged to spring, so that it engages against the locking surface to hold the blind or screen in the required position against retraction. The locking member is prevented from moving into the return passage by the provision of the stop. However, when it is desired to retract the blind or screen, all that is necessary is for the end rail to be moved a small distance away from the retracted position so that the locking member passes over the stop and can then be pushed, or can spring, into the return passage along which it can pass to allow the blind or screen to retract.

In a preferred construction the locking member is movable relative to said support and is spring urged relative to said support in a direction to urge said locking member against said locking surface or into said return passage. The provision of the locking member in such a way as to be spring urged saved manipulation of the end rail and. renders substantially automatic firstly the engagement of the locking member against the locking surface to latch the blind or screen and secondly facilitates the unlatching because movement of the end rail away from the retracted position will enable the locking member to spring into the return passage automatically.

is Advantageously the return passage is adapted to be positioned close to the plane of the blind or screen. The other end part of the ramp may extend over said return passage but be movable away to allow said locking member to pass out of said return passage. This may be achieved by the other part of the ramp being resiliently urged to the position covering said return passage for example by being sufficiently flexible to enable it to be moved away by movement of said locking member.

With such a construction the second part preferably has an abutment to support said other end part of said ramp to prevent it from moving beyond its normal inclined position in a direction opposite to that in which it flexes to allow said locking member to pass.

The second part may include an additional guide ensuring that said locking member moves to the space adjacent said locking surface without accidentially moving past said stop.

In order that the present invention may more readily be understood the following description is given, reference being made to the accompanying drawings, in which:Figure 1 is a perspective view of a portion of a retractable screen or blind provided with one embodiment of latch assembly according to the present invention; 5 Figure 2 is a schematic side elevation. from the opposite end to that shown in Figure lp illustrating operation of the latch assembly; and Figure 3 is an exploded view showing the various parts of the latch assembly in perspective. 10 The blind or screen shown in Figure 1 is illustrated as an insect screen including screen material 10 which is connected at the top to a retractable spring loaded roller (not shown) of the perfectly conventional type, and at the lower end to an end bar 12. The sides of the screen are guided by side frame members 14 so that the blind cannot readily move in the direction transverse to its plane. This prevents insects from penetrating around.the side edges of the screen.

Mounted on each end of the end bar are the first part 16 of the latch assembly indicated by the general reference numeral 18 of the invention. The first part 16 as can be seen in Figure 3 includes a support 20 including a plug 21 for insertion into a hollow portion 22 of the end rail. The support 20 is provided with a pivot pin 24 upon which is mounted a pivotal latch 26, the latch being secured to the pivot 24 by a screw 28 and being urged in a generally counterclockwise direction, as seen in Figure 3, by a torsion spring 30. The latch 26 includes a laterally extending locking member 32 in the form of a pin.

The assembly is shown associated with a windowsill 34 on which is mounted a second part 36 of the latch assembly. This includes an inclined ramp 38 and which positioned at a generally rearwardly extending wall member having a lower locking surface 42. Behind the rearwardly extending wall member 40 is a generally vertically extending -5wall 44 including a downwardly extending portion 46 forming a stop member and an upwardly extending portion 48 forming a support wall to be described later. An accommodation spare at 50 is formed below the locking surface 42 and in front of the stop 46. Extending upwardly into this accommodate space is an additional guide 52 which extends in front of the gap 54 below the stop member.

The wall 44 defines the front surface of a return passage 56. The ramp 38 includes a lower part 58 and an upper part 60 which is generally flexible and can pivot, because of its flexibility, to the phantom line position 62. Pivoting in the opposite direction is substantially precluded by the upper surface of the support wall 48.

In use, the blind is pulled down by grasping the end bar 12 and the sequence of operations is shown schematically in Figure 2. The locking pin 32 is shown being moved down and is initially in the position A. It engages, at position B, the upper end part 60 of the ramp 38 and then slides down via position C to position D below and in front of the lower end 58 of the ramp 38. The action of the spring 30 will then pivot the locking pin 30 first to position E and then to position F at which it is engaged against the locking surface 42. Unwanted further rearward movement of the locking pin is prevented by the stop 46.

The additional guide 52 is provided to prevent the locking pin 32 from accidentially passing through the gap 54 below the stop 46. With the locking pin in the position F the blind will be retained in this position.

When it is desired to release the blind, one again grasps the end bar 12 and pulls it downwardly. The' locking pin will then move, partly due to this downward movementy and partly due to the action of the spring 30 via the position G and thence under the stop 46 and through the gap 54 to the position H. If the end bar is then released, the retraction spring in the roller of the screen will pull the screen upwardly with the locking member 32 passing upwardly through the return passage 56. It will then engage the lower surface of the upper portion 60 of the ramp 38 which will then flex out to the position 62 to allow the locking member 32 to continue to move upwardly# thereby releasing the blind or screen.

It will be appreciated that the construction illustrated is very simple to operate and can in fact both be locked and unlocked using a single hand which makes it far simpler than known latching assemblies used with blinds or screens.

If desired, the spring loading of the locking member can be omitted and the latching and unlatching can be effected by manual movement, causing the locking member 32 to move along the path A, B, C# Dr E, Fi G, H. However, the provision of the spring loaded member 26 with the locking pin 32 thereupon greatly facilitates the operation.

Claims

-7C L A I M S

1. A latch assembly for a retractable blind or screen, to releasably lock the blind or screen in a required position, said assembly comprising a first part attachable to or integral with a movable end bar of the blind or screen, to move with the end bar and a second part locatable in a stationary position and engageable with or disengageable from the first part by operating the end bar, the first part of the assembly including a support and a laterally extending locking member mounted on said support, the second part of the assembly including an inclined ramp, a generally rearwardly extending member behind one end part of the ramp, said member having a locking surface engageable by said locking member to hold said blind or screen in a required position against retraction, a return passage communicating with the space occupied by said locking member when it is engaged against said locking surface and through which said locking member may pass, to allow the blind or screen to return towards its retracted position and a stop between said space and said return passage, said stop preventing said locking member passing accidentally into said return passage, but allowing said locking member to pass when the blind or screen is moved away from its retracted position so that the locking member is moved away from the locking surface. 25

2. An assembly according to claim 1, wherein said locking member is movable relative to said support.

3. An assembly according to claim 2, wherein said locking member is spring urged relative to said support in a direction to urge said locking member into said space or into said return passage.

4. An assembly according to claim 2 or 3, wherein said locking member is pivotal relative to said support.

5. An assembly according to any preceding claim, wherein the return passage is adapted to be positioned close to the plane of the blind or screen.

6. An assembly according to any preceding claim, wherein the other end part of the ramp extends over said return passage but is movable away to allow said locking member to pass out of said return passage.

7. An assembly according to claim 6, wherein said other end part of the ramp is resiliently urged to the position covering said return passage.

8. An assembly according to claim 7, wherein said ramp wall is sufficiently flexible to enable it to be moved away by movement of said locking member.

9. An assembly according to claim 7 or 8, wherein said second part has an abutment to support said other end part of said ramp to prevent it from moving beyond its normal inclined position in a direction opposite to that in which it flexes to allow said locking member to pass.

10. An assembly according to any preceding claim, wherein said second part includes an additional guide ensuring that said locking member moves to the space adjacent said locking surface without accidentally moving past said stop.

11. A latch assembly for a retractable blind or screen, said assembly being substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.

Published 19% atThePatent Office. State House, 66,71 High Holbom, UndonWC1R4TP. F'urther Copies maybe obtained from The PatentOMce. Sales Branch, St Mary Cray, Orpington, Xent BW 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent, Con. 1187