AU3532600A - A lock - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): RIPPONLEA AUSTRALIA PTY LTD A.C.N. 052 035 739 Invention Title: A LOCK The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 A LOCK This invention relates to an improved lock especially a lock that incorporates a separate latch and deadlocking bolt.

There are many locks that incorporate a latch that can be released by depression or turning of a handle and a deadlocking bolt that is usually driven by a locking cylinder via a key to place the lock in a locked configuration. These locks usually include a mechanism that prevents the locking bolt from being pushed back into the casing from the exterior. This is known as a deadlocking feature. A problem with locks of this kind is 15 that it sometimes requires two hands to open a lock. The first hand to turn the key and pull back the deadlocking bolt and a second hand to depress the handle to release the 0 latch. Whilst locks do exist including a mechanism to release both the deadlocking bolt and latch on turning of 20 the key, these locks tend to be bulky, complex and consequently expensive.

It is the aim of the present invention to devise a lock that can be released with one hand that is small, simple in construction and cheaper to produce.

According to the present invention there is provided a lock including a casing that houses a latch bolt that is mounted to a latch plate, the plate being driven by a lock handle, a deadlocking bolt mounted on a deadlocking plate, the plate being driven by a locking means to deadlock the deadlocking bolt, and a bridging piece mounted on the deadlocking plate to extend between the deadlocking plate and the latching plate adapted so that movement of the locking means to move the deadlocking plate to withdraw the deadlocking bolt causes movement of the bridging piece to pull back the latch plate and release the latch.

\\melbO\hom'\Mo-ique\Keer\speci\F'38335 .dQQ 15/05/00 3 An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a side view of the interior of a lock of the present invention; Figure 2 is an end view of a face plate used with the present lock; Figure 3(a) is a side view of a latching assembly of the lock; Figure 3(b) is a side view of a handle pivot arm of the lock; Figure 3(c) is a side view of a locking assembly *of the lock; 15 Figure 3(d) is a side view of a bridging piece of the lock; and Figure 3(e) is side view of a deadlocking slide of the lock.

The lock shown in the accompanying drawings comprises a lock casing 10 of rectangular configuration. As seen in Figure 1, the lock has a suitably profiled latch 18 and a deadlocking bolt 40 that are adapted to be received in a forward facing face plate 11 shown in Figure 2. The face plate 11 has two spaced apart rectangular apertures 13 and 14 the first aperture 13 provides access for the latch 18 and the second aperture 14 provides access for the deadlocking bolt 40. The latch 18 has a tapered contact surface (not shown) and is screwed to one end of a displaceable latch plate 20 by screws 21 shown in Figure The deadlocking bolt 40 is screwed onto the end of a deadlocking plate 41 shown in Figure The handle (not shown) of the lock extends through the square centre 22 of a rotary member 25 shown in Figure 3(b) that has projecting arms 26, 27 that are arranged to engage upwardly turned end faces of legs 31, 32 of the latch plate 20. A fixed abutment flange 35 is provided on the lock casing and an \\melbOI\hone$\Monilue\Keep\speci\38335 -]oc 15/05/00 YI I 4 oil spring 36 is mounted between the abutment 35 and a lug 37 on the interior surface of the latch 20. The oil spring 36 as shown in Figure 1 urges the latch 20 outwards to extend through the aperture 13 in the face plate 11. As the door handle is turned in either direction the arms 26, 27 pull back the latch plate against the spring 36 to pull the latch into the confines of the lock.

The deadlocking bolt 40 is similarly mounted on the plate 41 shown in Figure 3(c) that is slidable on a pin 53 that is mounted in the lock casing and extends through an elongate slot 54 in the plate 41. A locking cylinder has an actuating arm 61 that on turning of the key coUtterclockwise as seen in Figure rotates about the axis of o 15 the locking cylinder 60 to engage a recess 63 in the locking plate 41 and specifically an abutment 62 of the recess 63 to drive the locking plate 41 forwardly and urge the locking bolt 40 to the outwardly projecting lock position (not shown).

A deadlocking slide 70 shown in Figure 3(e) is mounted on top of locking plate 41 and pivoted about the pin 53. Leaf spring 71 acts between the deadlocking slide 70 and the flanged abutment 35 of the lock casing to bias locking slide 70 downwardly and towards the left of the lock as seen in Figure The deadlocking slide 70 has an elongate slot 73 with a central shoulder 75 that engages with a projection 74 on the deadlocking plate 41 so that the when the spring 71 urges the shoulder 75 behind the projection 74 it is impossible to push back the deadlocking bolt 40 from the exterior. To release the deadlocking bolt a key has to be turned clockwise in the locking cylinder to cause the arm 61 to engage an abutment 76 on the deadlocking slide 70 causing it to pivot upwardly about the pin 53 against the spring 71 releasing the projection 74 on the locking plate from the shoulder 75 and allowing further turning of arm 61 to engage with recess 63 of locking plate ielbO I \home5 \Mon qiue\Kep\ speci '38J35 .doc 15/05/00 I I II 5 41 thereby allowing deadlocking bolt 40 to be drawn back into the casing The problem with locks of this kind is that often two hands are needed to open the lock namely a first hand has to turn the key to unlock the deadlocking bolt 40 whilst the second hand then turns or depresses the lever to release the latch bolt 18. However, in the lock described herein a bridging piece 80, and more specifically a lever, that is shown in Figure 3(d) is pivotally positioned on top of the latch and locking plates 40 and 41 to pivot about an upward extending pin 81 at an upper extremity of the dead locking plate 41. The bridging piece is in the form of an arcuate strip of steel having opposed first and second ends 83 and 15 85 with an outwardly projecting flange 82 positioned between the ends. Pin 81 extends through an aperture 84 provided on second end 85 of the bridging piece 80. The first end 83 of bridging piece 80 is engaged by the arm 61 on the lock cylinder 60 to cause the bridging piece 80 to 20 pivot so that the projecting flange 82 of the bridging Piece 80 engages the upwardly turned flange on the lower leg 32 of the latch plate 20. The distance between the point of engagement on the lock cylinder on bridging piece 80 and its pivoting point 84 has the advantage of creating a moment to cause a smooth action to draw back the bolt through contact of flange 82 with leg 32 of the latch plate.

Thus turning of the key in a clockwise direction as seen in Figure 3 to unlock the deadlocking bolt has a dual effect of moving the locking plate 41 and locking bolt 40 as well as through interaction of the bridging piece 80 20 smoothly causing the latch 18 to be pulled back.

The lock described above is designed to be simple in construction, has a minimum number of moving parts and yet provides an effective latching and deadlocking lock with \\melbO1\home$\Monicpse\Klee\spe f-3833 5. oc 15/05/00 I

I

-6 single handed operation. The lock is compact but can where necessary be made with larger components for a sturdier lock as desired.

It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention.

\\melbO1\home-$\Moni-ue\Keel\.peci\FE38J35.ctoc 15/o5/00

Claims (12)

1. A lock including a casing that houses a latch bolt that is mounted to a latch plate, the plate being driven by a lock handle, a deadlocking bolt mounted on a deadlocking plate, the plate being driven by a locking means to deadlock the deadlocking bolt, and a bridging piece mounted on the deadlocking plate to extend between the deadlocking plate and the latching plate adapted so that movement of the locking means to move the deadlocking plate to withdraw the deadlocking bolt causes movement of the bridging piece to pull back the latch plate and release the latch. 15

2. The lock claimed in claim 1 wherein the bridging piece is an arcuate pivoting lever which pivots to engage at a first flange with the latch plate to pull it back into the casing.

3. The lock claimed in claim 2 wherein the lever e* Pivots about a pin on the deadlocking plate.

4. The lock claimed in claims 2 or 3 wherein the locking means is a key cylinder having a actuating arm which rotates around the cylinder.

The lock claimed in claim 4 wherein on rotation of the actuating arm in a first direction, the arm engages with a second flange of the lever to cause the lever to pivot and engage with the latch plate.

6. The lock claimed in claims 4 or 5 wherein on rotation of the actuating arm in a second direction, the arm engages with a recess on the deadlocking plate to drive the deadlocking bolt outwardly of the casing.

7. The lock claimed in any one of the preceding \\melbO1\home\Monique\Kep\.peci\EJ3833rSidoc 15/05/00 8 claims wherein a deadlocking slide prevents movement of the deadlocking plate.

8. The lock claimed in claim 7 wherein the deadlocking slide has an elongate slot with a shoulder that engages a projection on the deadlocking plate.

9. The lock claimed in claim 8 wherein the locking slide is biased to maintain engagement with the deadlocking plate.

10. The lock claimed in claim 9 wherein the deadlocking slide is biased by a leaf spring fixed at-one end to the casing.

11. The lock claimed in any one of claims 7 to wherein on rotation of the actuating arm in the second direction, the arm contacts the slide to move it to disengage from the deadlocking plate.

12. A lock substantially as herein described with reference to and as illustrated by the accompanying drawings. a Dated this 15th day of May 2000. RIPPONLEA AUSTRALIA PTY LTD By Its Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia \\melb01\homeS\Monique\Keep\speci \f38335 .doc 15/05/00