GB2398102A

GB2398102A - Lockable releasable safety catch for a slidable panel

Info

Publication number: GB2398102A
Application number: GB0400050A
Authority: GB
Inventors: Peter James Harrison
Original assignee: J Banks and Co Ltd
Current assignee: J Banks and Co Ltd
Priority date: 2003-01-04
Filing date: 2004-01-05
Publication date: 2004-08-11
Anticipated expiration: 2024-01-05
Also published as: GB0300150D0; GB0400050D0; GB2398102B

Abstract

A lockable releasable safety catch 30 for a slidable panel 12 comprising a catch member 40 resiliently biased to project from a body 32. The catch 30 is characterised by a lock member 46 that has an active position in which it prevents the catch member being moved into the body, and an inactive position in which the catch member can be moved into the body 32. The lock member 46 is movable from its active position to its inactive position by a key 52. The body is adapted for mounting to or adjacent to the panel. The catch member 40 may be biased by a compression spring 42. The lock member 46 may be resiliently biassed towards its active position. The catch 30 may typically be used to limit or restrict the opening movement of a sliding window 12.

Description

LOCKABLE RELEASABLE SAFETY CATCH

FIELD OF THE INVENTION

This invention relates to a lockable releasable safety catch, and particularly to a lockable releasable safety catch for sliding windows. The catch can be used for opening panels other than windows, but for simplicity the

following description will refer only to windows.

Releasable safety catches of this type are typically used to limit or restrict the opening movement of a window or other panel, and so are often referred to simply as "restrictors".

BACKGROUND TO THE INVENTION

The safety problems associated with openable windows, particularly those several metres or more above ground level, have long been recognised, and have been highlighted À:. 20 by reports of children opening such windows and falling from considerable heights. It has, however, proved unacceptable to the occupants to have the windows permanently sealed and A. À . unopenable, and the fire authorities desire that the windows : be openable to allow escape in the event of a fire. À

An effective safety catch is thus required, operable to limit or restrict the distance by which the window may be opened, but which is releasable to allow the window to be fully opened when desired, for example to allow maximum ventilation or for cleaning.

A sliding window typically comprises an outer frame which is mounted in the brickwork of the building. The frame has a pair of opposed channels (which are usually arranged to run vertically) within which can slide a glazed sash.

Typically, the sliding sash is an outer sash which can slide behind an inner sash as the window is opened (the terms "outer" and "inner" referring to their relative location - 2 with respect to the inside of the building). The frame may have a pair of channels only for the outer sash, in which case the inner sash is fixed to the frame; alternatively both of the outer sash and inner sash are slidable relative to the frame, and to each other.

DESCRIPTION OF THE PRIOR ART

A known releasable safety catch for use with hinged panels is described in U.K. Patent 2,263,934. This device is suitable for use on sliding panels.

A known releasable safety catch for use on sliding windows comprises a metal plate which is permanently secured to the frame part of the outer sliding sash, the plate having a threaded hole which can accommodate the threaded shank of a bolt. The bolt has an enlarged head which when fitted to the plate acts as a stop for engaging the inner sash. It is À:. 20 arranged that the outer sliding sash can be moved a certain distance before the bolt head engages the inner sash, so limiting or restricting the opening movement of the sliding A. sash(es). The degree of opening movement possible can be À. chosen by the installer, but will typically provide a large enough opening to permit substantial ventilation, but not large enough to allow a child to pass through the opened window.

The bolt head carries a freely rotatable sleeve which acts as an antitamper device, rotation of the sleeve not being transmitted to the shank so that the bolt cannot be removed from the plate by rotating the sleeve. To remove the bolt a special tool is required to be inserted inside the sleeve and rotate the bolt head directly. The requirement for a special tool makes unauthorized disabling of the device less likely. - 3 -

This known device has a number of disadvantages. Firstly, when the bolt has been removed the device remains disabled until the bolt is replaced. The special tool is also required to connect the bolt to the plate, and failure to locate and use the special tool may cause the bolt not to be replaced when the window is subsequently closed. Also, the bolt may become lost after it has been removed. Without fitment of the bolt, the device is inoperable and the window can be fully opened at all times. Furthermore, the special tool which is required to remove the bolt may become lost, so that the bolt may not thereafter be replaced or removed (as applicable).

Another prior art device is disclosed in U.S. patents 4,923,230 and 5,248,174. Those documents describe a releasable safety catch having a body which is fitted into À- : one of the frame parts of the outer sliding sash, the body carrying a catch member which is spring-biassed out of the body. If and when it is desired to open the window beyond :. 20 the restriction imposed by the catch member, the safety catch may be released by manually pressing the catch member into the body, so allowing the outer sash to pass (further) À . behind the inner sash. Whilst the window remains open a À . part of the inner sash overlies the catch member and keeps it pressed into the body. When the window is closed again the safety catch automatically becomes activated, i.e. the catch member is biassed out of the body as soon as it becomes free of the inner sash.

This device has the significant disadvantage that it may easily be disabled by a child, i.e. very little effort is required to depress the catch member into the body, and a child may easily depress the catch member and subsequently open the window. This disadvantage is exacerbated because of the facility to retain the device in its disabled condition, i. e. it is possible to locate the catch member relative to the body so that it remains within the body and does not project therefrom. When so disabled, unhindered - 4 - (repeated) opening of the window is possible. This disadvantage is also exacerbated by the fact that the device is clearly visible on the outer sash, i.e. the catch member must necessarily project from the outer sash into the building, and may attract the attention of a child.

STATEMENT OF THE INVENTION

The present invention seeks to overcome or reduce the disadvantages of the prior art safety catches described above. Specifically, it seeks to provide a releasable safety catch which is lockable in the operable condition, and which requires a key to disable or release it.

According to the invention therefore, there is provided a lockable releasable safety catch for a slidable panel including a body adapted for mounting to or adjacent to the panel, and a catch member movably mounted to the body and :: 20 resiliently biassed to project from the body, characterized À.. by a lock member which has an active position in which it prevents the catch member being moved into the body, and an inactive position in which the catch member can be moved À into the body, the lock member being movable from its active position to its inactive position by a key.

In use with sliding windows in which the outer sash is slidable (and in which both the inner and outer sashes are slidable) the body is preferably mounted to the outer sash.

Preferably, the lock member is resiliently biassed towards its active position, so that the key is only required to move it from its active position to its inactive position.

Desirably, the lock member is carried by the catch member, and the lock member in its active position engages a part of the body. Desirably also, the catch member has a key slot - 5 - into which the key may be inserted so as to move the lock member to its inactive position.

Preferably, the key is only required to be inserted to move the lock member to its inactive position, i.e. rotation of the key is not required. Thus, it is recognized that the lockable releasable safety catch is primarily a safety device rather than a security device, and the requirement for key operation is intended to reduce the likelihood of a child disabling the device, for example. Complex, large and expensive locking arrangements are therefore not likely to be required, but can of course be provided if necessary.

Preferably, the body includes guide means for the catch member. In this way, the catch member is guided for sliding movement relative to the body. Desirably, the catch member carries projecting lugs which locate into correspondingly I...

shaped and sized channels in the body. The use of lugs and channels makes the catch member more secure relative to the À 20 body, it being desired that the catch member be sufficiently . robust to withstand repeated impacts upon the inner sash (i.e. when the device is enabled), and to be substantially À.

À . immovable under such impacts. Àe

Desirably, the channels converge towards their outer ends, so as to provide a more positive location for the catch member when it is in its enabled (projecting) condition.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig.l is a front view of a sliding window fitted with a lockable releasable safety catch according to the invention; - 6 - Fig.2 is a perspective view of part of the window of Fig.1; Fig.3 is a view as Fig.2, with the window opened to its restricted limit; Fig.4 is a cross-sectional view of the lockable releasable safety catch in its enabled condition/ and the key therefor; Fig.5 is a view as Fig.3, with the key inserted and the catch disabled; Fig.6 is a view similar to that of Fig.5, with the key removed; Fig.7 is a cross-sectional view of the lockable releasable safety catch in its disabled condition; A. and . :. Fig.8 is a side view of the lockable releasable safety catch in its enabled condition. Àe À À. À .e À À

DESCRIPTION OF THE PREFERRED EMBODIMENT

The sliding window 10 shown in Fig.1 has an outer sliding sash 12 and an inner sash 14, both mounted in a frame 16.

Each sash 12, 14 comprises a respective frame part 20, 22 which surrounds and supports glazing (not shown).

In this embodiment the inner sash 14 is also slidably mounted in the frame 16, but in other embodiments is fixed thereto. Both of the inner sash 14 and the outer sash 12 are slidable vertically (as drawn) within channels (not shown) of the frame 16. Typically, the frame 16 carries counter-weights or tensioning means (not shown) to counterbalance the weight of the sashes and make moving the - 7 - sashes easier. The sashes 12, 14 are secured in their closed positions by a locking means 24, which may be of conventional design.

In this example, the frame 16, and the frame parts 20 and 22 are of timber, but in other examples the frame and/or the frame parts can be of plastics or metal.

The sliding window 10 carries a lockable releasable safety catch 30 according to the present invention. As better seen in Fig.4, the safety catch 30 has a body 32 which in use is rebated into the frame part 20 of the outer sash 12.

Connected to the body 32 is a fixing plate 34 having screw holes 36 to receive screws or other fixing means by which the body 32 is secured to the frame part 20. A catch member is mounted to the body 32 and is biassed by a compression A. 1 : spring 42 so as to project from the body 32. The catch . À . member 40 has a substantially flat contact surface 44 which as shown in Fig.3 engages the top edge of the frame part 22 of the inner sash 14 as either the outer sash 12 is lowered À.. or the inner sash is raised. The safety catch 30 is positioned relative to the sash 12 to allow restricted I. À. opening movement of the window, specifically to allow the À. .e À .. sashes 12 and 14 relative movement over a distance "X" (Fig.l). The distance "X" can be set according to the desired restricted opening movement, or according to the applicable standard in force, for example.

The normal condition of use of the window will be with the safety catch enabled, and the window being opened as often as desired by a distance less than or equal to "X". If, however, it is desired to open the window further (as might for example be desired to allow more ventilation into the room or building, or if the window is to be used to escape a fire), the safety catch can be disabled.

As seen in Fig.4, the catch member 40 carries a lock member 46, which in conventional design is a flat plate with an - 8 - opening 50 to receive a key 52. The lock member 46 is guided to move relative to the remainder of the catch member 40, in a direction substantially perpendicular to the direction of movement of the catch member 40. The lock member 46 is biassed by a spring (not shown) into its active position as shown in Fig.4.

The body 32 has a ledge 54 which is engageable by a part 56 of the lock member 46. When the lock member 46 is in its active positon as shown in Fig.4, the part 56 engages the ledge 54 and prevents the catch member 40 being pressed into the body 32, so that the catch member is retained in its enabled condition as shown.

The catch member 40 has a key-way 60, within which lies a part of the lock member 46. When the key 52 is inserted À. into the key-way 60 it engages the lock member 46 and causes I. the part 56 to be withdrawn into the catch member 40, i.e. into its inactive position. Once the lock member 46 is in

I

À À 20 its inactive position, the part 56 no longer overlies the À ledge 54, and the catch member 40 can be pressed into the body 32. (The pressing of the catch member 40 into the body À À. 32 is usually a continuation of the force applied to insert À ..

the key 52).

Fig.5 shows a view similar to that of Fig.3, but with the key 52 inserted and the catch member 40 disabled, i.e. pressed into the body 32. When the catch member 40 is disabled, the contact surface 44 is moved into (or substantially into) the body 32, and is no longer engageable with the frame part 22 of the inner sash 14. Accordingly, the outer sash 12 may be lowered relative to the inner sash 14, to open the window further.

As will be seen in Fig.6, it is arranged that the catch member 32 is sufficiently long in the direction of movement of the sash that a part of the catch member 40 can be moved behind the frame part 22 whilst the key 52 remains in the - 9 key-way 60. In this way, pressure can be maintained upon the catch member (or upon the key 52) to hold the catch member in its disabled condition, whilst a part of the catch member 40 is moved behind the frame part 22. When a part of I the catch member 40 is behind the frame part 22, as shown in Fig.6, the frame part 22 retains the catch member in its disabled condition and the key 52 may be removed.

During further opening movement of the window, the outer surface 62 of the catch member 40 rides along the back surface of the frame part 22. It will be seen that the leading and trailing ends of the outer surface have a slight chamfer to facilitate passage of the catch member past the seals which will be fitted to the frame part 22. In this embodiment the top and bottom edges of the fixing plate 34 are not chamferred, but they can be chamferred if required À. or desired to pass the seals. see. À . À.ee

As seen in Fig.7, as long as the catch member 40 remains in its disabled condition, the lock member 46 is retained in :. its inactive position, i.e. the spring biassing the lock member 46 towards its active position causes the lock member À 46 to slide along the inner surface 64 of the body.

À . .. À . À e

When the window is subsequently closed sufficiently to allow the catch member 40 to be free of the frame part 22, the catch member 40 is urged outwardly of the body by the spring 42; when the catch member 40 has been moved to its enabled condition the lock member 46 is automatically biassed to its active position, i.e. the lock member 46 moves relative to the catch member as soon as the part 56 of the lock member 46 passes the ledge 54. Thereafter, to open the window further than the distance "X" will require insertion of the key 52 once again.

The embodiment described is the preferred embodiment in which the catch member is automatically locked when it moves to its enabled condition. However, it is clearly possible - 10 to provide alternative embodiments in which the key is required to move the lock member to its active position; one suitable embodiment has a non-biassed lock member which is moved into and out of its active position by rotation of a key.

In the automatically-locking embodiment described, the key 52 can be of very simple form since it is only required to enter the key- way 60 and move the lock member 46 until the part 56 clears the ledge 54. This function could in principle be performed by a flat blade, but the key-way 60 is deliberately of special form (see Figs. 1 and 2 for example) to prevent the insertion of a flat blade such as a screwdriver, since it is desired that a screwdriver or the like should be unsuitable for unlocking safety and security devices such as this. À.e À. À

À. It would of course be possible for the same key 52 to operate the lock 24, so that only a single key is required for the window 10 (or indeed all of the windows of the room or building). A. À

The catch member 40 in the embodiment shown has only a À . À À single lock plate 46, and the body has only a single ledge 54. If a more complex locking means was desired more lock members, and more ledges, could be provided, necessitating a more complex key design.

Fig.8 shows an external side view of the safety catch. As shown, the body 32 has two channels 66 formed in its side wall 70 (in this embodiment the channels are created by removing parts of the side wall 70). The catch member 40 has projecting lugs 72 which each locate within a respective channel 66. The channels 66 converge slightly towards their front end 74 (i.e. the end closest to the fixing plate 34), so that the front end 74 of each channel 66 provides a secure location for the lug 72 with little freedom of transverse movement. It will be understood that the lugs 72 11 - engage the front end 74 of their respective channels 66 when the safety catch is enabled, and is accordingly in the position in which the surface 44 can impact the inner sash 14. The more secure location of the lugs 70, and therefore the catch member 40, when in this position reduces the possibility that the catch member will be moved when impacting the inner sash.

As described, the frame 16 and the frame parts 20 and 22 in this example are of wood, but could alternatively be plastics or metal (typically aluminium). With such alternative materials it may be necessary to provide additional mounting means to secure the body 32 to the frame. In addition, with all frame materials it may be desirable to mount the safety catch so that when the catch member 40 is in its disabled condition it is substantially flush with the surface of the frame, so facilitating easy À À. movement of the safety catch past the seals. He e À ' À.. À À*e À . À 12

Claims

1. A lockable releasable safety catch for a slidable panel, the catch including a body adapted for mounting to or adjacent to the panel, and a catch member movably mounted to the body and resiliently biassed to project from the body, characterized by a lock member which has an active position in which it prevents the catch member being moved into the body, and an inactive position in which the catch member can be moved into the body, the lock member being movable from its active position to its inactive position by a key. l

2. A lockable releasable safety catch according to claim 1 in which the lock member is resiliently biassed towards its active position. a:. Abbe

À, .

3. A lockable releasable safety catch according to claim 1 or claim 2 in which the lock member is carried by the catch member, and the lock member in its active À position engages a part of the body.

4. A lockable releasable safety catch according to claim 3 À . in which the catch member has a key slot into which the key may be inserted so as to move the lock member to its inactive position.

5. A lockable releasable safety catch according to claim 4 in which the lock member is moved to its inactive position upon full insertion of the key into the key slot.

6. A lockable releasable safety catch according to any one of claims 1-5 in which the body includes guide means for the catch member.

7. A lockable releasable safety catch according to claim 6 in which the catch member carries at least one projecting lug which locate(s) into a respective correspondingly shaped and sized channel in the body.

8. A lockable releasable safety catch according to claim 7 in which the or each channel is formed by removing a part of the wall of the body.

9. A lockable releasable safety catch according to claim 7 or claim 8 in which the or each channel converges towards its outer end.

10. A lockable releasable safety catch constructed and arranged substantially as described in relation to Figs. 2-7 of the accompanying drawings. :. À.e. À.e. À Àeee

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