AU685223B2 - Sliding window or door lock - Google Patents

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT SLIDING WINDOW OR DOOR LOCK THE FOLLOWING STATEMENT IS A FULL DESCRIPTION OF THIS INVENTION, INCLUDING THE BEST METHOD OF PERFORMING IT KNOWN TO ME:- The present invention relates to a lock for a sliding window or door. In particular, the invention relates to a bolt-type lock which can lock the window in a fully closed or partially open position as desired.

o The present invention aims to provide a window lock which is easy to operate, or at least gives the public a useful choice.

The invention thus provides a lock for a sliding door or window sash, having a housing, a bolt supported by the housing, the bolt being transverse to the direction of sliding of the sash and biased towards an extended latching position in which the bolt engages with a fixed formation to prevent sliding of the sash, non-key actuated unlatching means for retracting the bolt from the latching position and key actuated means for locking the bolt in the latching position.

The invention also provides a sliding door or window with a sliding sash which has a lock of the type described.

Preferably, the fixing formation comprises one or more apertures in the window track, with the bolt -2being biased outwards from the housing to be pushed into engagement in the aperture. The window track or the like preferably has a flat surface between said apertures so that the bolt can slide along the track until it comes into alignment with an aperture.

Further pr, ferred embodiments will now be described with reference to the accompanying drawings, in which: Fig. 1 illustrates the lock mounted on the mullion of a sliding w-idow; Fig. 2 is a perspective view of the lock when removed from the window; Fig. 3 is an exploded view of the lock; S"Fig. 4A is a rear view of the lock in the latched and locked position; e Fig. 4B is a sectional elevation of Fig. 4A; Fig. 5A is a rear view of the lock in its unlatched position; and Fig. 5B is a sectional elevation of Fig. With reference to Fig. 1, a sliding window has a window pane 10 enclosed in a rectangular sash frame for sliding along a fixed window track 12. A side member of the sash frame consists of a mullion 14 having a transverse flange 16 which can be used as a handle for sliding the window. The mullion also has a sealing flange 18 parallel with the window pane for overlapping with part of a fixed vertical member when the window is closed so as to make a weather proof seal. The bottom member 20 of the sash may have I I rollers or slides to allow sliding within the fixed track 12.

The lock according to the invention is conveniently positioned in the right angle defined by the transverse and sealing flanges of the mullion, adjacent the top or bottom of the window. The lock is preferably attached to the transverse flange 16, conveniently by means of beads 22 on the housing 24 of the lock. The beads are provided on both sides of the housing to allow use of the lock on left or right opening windows.

The lock generally consists of a housing 24 with a rear cover 26, a barrel 28 and a bolt 30 which extends downwardly from the housing to engage in an aperture (not shown) in the track. Extending through the front of the housing is a handle 32 attached to the bolt, which serves as an unlatching handle for disengaging S: 20 the bolt from the aperture. To do this, the handle is E' pushed upwards as shown by the arrow 34 in Fig. 2.

o o The bolt can be locked in its latching position by turning the key 36.

25 Referring to Fig. 3, it can be seen that the housing is generally rectangular, with a circular opening in "its front face for housing a cylindrical lock barrel and a further generally rectangular opening for allowing sliding movement of the unlatching handle.

0• Mounted within the housing for up and down sliding movement is the bolt, which is formed as a pair of vertical, displaced legs joined by a short horizontal shelf portion 50. The upright leg 38 has a cutout portion 40, as described below with reference to Figs. 4A to I -4- The unlatching handle 32 is attached to the front face of the downward leg 42 of the bolt so that it protrudes through the rectangular hole in the housing.

A flexible tongue 44 is attached to the front of the downward leg of the bolt by a barb 46, the purpose of which will be described below. The bottom part 48 of the sliding bolt is adapted to extend below the housing to be engaged in the apertures in the track.

The horizontal shelf portion 50 of the bolt carries a peg 52 for retaining a compression spring 54 which operates between the bolt and the bottom of the cylindrical barrel housing 56 of the lock housing.

This biases the bolt downwards to the latching S 15 position shown in Figs. 4A and 4B.

With reference to Figs. 4A and 4B, the barb is shown in the latching position. The downward travel of the bolt is limited by the abutment of the handle 32 with the bottom of the rectangular aperture in the housing.

The bolt is locked in the latched position by the abutment of an eccentric pin 58 on the back of the lock barrel with the uppermost end of the upwards leg 38 of the bolt. This prevents the bolt from being slid upwards by use of the handle 32.

To unlock the bolt, the key is turned in the usual manner to rotate the barrel so that the eccentric pin is positioned above the cutout portion 40 of the upwards leg 38. However, even in this unlocked position, the bolt is still biased downwards by the spring and therefore the bolt is still in engagement with the apertures in the track. Unlatching of the bolt to allow sliding of the window can only be achieved by pushing the bolt upwards against the bias of the spring so that the bottom of the bolt is lifted clear of the aperture.

The purpose of the flexible tongue 44 is to create some friction in the mechanism to give operation of the latch some feeling of resistance. As the latch is lifted from the position shown in Fig. 4B to that shown in Fig. 5B, opposed ramping surfaces 60 and 62 on the tongue and the lock housing force the tongue to flex resiliently inwards. The protrusion 64 at the top end of the tongue is forced against the inner surface of the housing by the resilient force, thus creating some friction when the bolt is slid up or down.

The present invention provides a convenient locking e o mechanism for a sliding window which allows the sash to be locked in a choice of fully closed or partly opened positions, depending on the positions of the 20 apertures in the track. The sash can be moved between latching positions simply by pushing the unlatching handle upwards against the biasing force of the spring and sliding window. The bolt will slide across the surface of the track until it is aligned with another 25 aperture, at which stage the spring will force the bolt downwards into the aperture to latch the window in the new position. Thus, there is no need to align the bolt with an aperture and then push the bolt into engagement to latch the window. The latch is biased towards the latching position even when the key lock is undone, but the lock can be key locked to preclude unlatching.

While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the

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-6essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, and all modifications which would be obvious to those skilled in the art are therefore intended to be embraced therein.

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Claims (11)

1. A lock for a movable sash of a sliding door or window, having a housing, a bolt supported by the housing, the bolt being transverse to the direction of sliding of the sash and biased towards an extended latching position in which the bolt engages with a fixed formation to prevent sliding of the sash, non-key actuated unlatching means for retracting the bolt from the latching position and key actuated means for locking the bolt in the latching position.

2. A lock according to claim 1 wherein the unlatching means includes a handle protruding through an aperture in a face of the housing. r e 4 15

3. A lock according to claim 2 wherein said aperture is in a front face of the housing. 4*4e

4. A lock according to claim 3 wherein said aperture is extended in the direction of travel of the bolt to 20 allow the handle to move with the bolt.

5. A lock according to claim 1 wherein the bolt has e0:0 a pair rf displaced parallel legs joined at their proximal ends by a transverse shelf portion on which 25 a spring acts to bias the bolt towards the latching position.

6. A lock according to claim 1 wherein the locking means includes a key actuated barrel with an eccentric pin, actuable between a first position in which the pin abuts the bolt to prevent retraction and a second ~position in which the pin aligns with a cut-out portion of the bolt so that retraction of the bolt is I I not prevented.

7. A sliding door or window with a sliding sash having a lock thereon, the lock being according to any preceding claim.

8. A sliding window according to claim 7 wherein the window has a plurality of fixed formati.ons corresponding to closed and partially open positions of the sash.

9. A sliding window according to claim 8 wherein the fixed formations comprise apertures in the window track.

A sliding window according to claim 9 wherein the track has a flat surface between said apertures so that the bolt can slide along the window track i until the bolt aligns with an aperture. 20

11. A lock substantially as herein described with reference to the accompanying drawings. DATED this 23rd day of September 1997. Sg WHITCO PTY. LIMITED By their Patent Attorneys HALFORD CO 9 -9- ABSTRACT A lock for a sliding door or window sash comprises a housing (24) and a bolt (30) biased by means of a spring (54) towards engagement with an aperture in a track An unlatching handle (32) passes through the front of the housing (24). 0