AU656896B2 - Improvements in door locks - Google Patents

Description

Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIF[CAT!ON FOR A STANDARD PATENT

(ORIGINAL)

656896 o 00 0 0 00 0 00 0 9 0 0000 .90000 0000 0000 0 00 *9 0 0 00 0000 9090 00~~0 o 00 00 .00*40 *000'0 0 00S0 0 0 0 00 0040 0000 Name of Applicant: Actual Inventor(s): Address for Service: Invention Title: JOHN RUSSELL WATTS JOHN RUSSELL WATTS DAVIES COLLISON CAVE, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000.

"Improvements in Door Locks" Details of Associated Provisional Application(s): No(s): PK0972/90 filed 4 July, 1990 PK1136/90 filed 12 July, 1990 The folIowing statement is a full description of this invention, including the best method of performing it known to me/us: -1 \~NT C 941108,q Aoper\rshwatts.59,1 IMPROVEMENlTS IN DOOR LOCKS This invention relates to door locks and in particular relates to door locks that include deadlocking latch bolts for use with both mortice and cylindrical locks.

To improve the security of door locks, it is desirable to provide a locking bolt that can assume, when in the deadlocked position, a deep penetration into a recess in the associated door frame. The deeper the locking bolt penetrates the door frame the less likelihood there is of the lock being levered open. However, for the same bolt to provide both locking and latching capacity it is considered important that the locking bolt does not project too far from the lock casing prior to latching. There is a danger that if the lock bolt extends too far from the casing, it will not ride up the strike plate in the door frame and could be damaged by the impact force that it would be subjected to as the door is closed against the strike plate. Thus, it has proved difficult to provide a single purpose lock bolt that adequately satisfies the features of latching and secure locking. It has been proposed to provide three positional lock bolts such that in a first position, the bolt .is substantially within the confines of the lock casing. In a second position, the lock bolt extends from the casing a short distance to assume a latching configuration and 2 in a third position, the locking bolt is, usually urged by biasing means, into a fully extended locked position. It is usual to provide an auxiliary bolt that acts as a detent to hold the locking bolt in the second latching position. When the auxiliary bolt is depressed by the striker plate the detent allows the lock bolt to be fired into the fully extended position. A problem with this arrangement is that it is possible to manually release the locking bolt to the fully extended position when the door is open by simply depressing the auxiliary bolt. In such cases, it is impossible to close the door. In some countries, this offends safety regulations associated with the latching and locking of doors. Other regulations require that door closing unlocks the locking mearns. This requires operable coupling between the latch bolt and locking means and this characteristic is missing from most bolts of extended length.

According to the present invention, there is provided a lock comprising a casing, a deadlocking latch bolt of extended length 'mupported within the casing and 941108p:\oper\rshDoor-ocks.spe,1 i= j -2displaceable relative to the casing between fully extended, partially extended, and retracted positions, biasing means for urging the latch bolt towards the extended position, latch bolt actuating means for displacing the latch bolt towards said retracted position, said actuating means including a connecting arm engageable with said latch bolt and crank means engageable with said connecting arm, a strike plate engageable by the latch bolt, and latching means operative to cause displacement of the bolt towards its retracted position from any extended position consequent on interaction between the lock and strike plate, said latching means comprising a ramped portion of the latch bolt and a lever carried by the latch bolt and engageable with the strike plate during latching to effect movement of the bolt towards its retracted position.

In a preferred embodiment the latching means includes an ari6,llarly displaceable lever supported within a recess in the latch bolt which is engageable by the strike plate during latching.

In a preferred embodiment the lock includes means to retain the latch bolt in its partly extended position, such retaining means preferably comprising releasable abutment means to restrain the latch bolt from being displaced to its fully extended position by the biasing means.

In a preferred embodiment, the lock includes interaction means for providing 20 operable interaction with latching. Preferably the operable interaction means includes an engageable spindle member actuatable by latching and preferably the :operable interaction means includes an angularly displaceable member actuatable during latching, wherein the angularly displaceable member is supported on and is 1engageable with a shaft, and the shaft is coupled to the spindle member. Preferably the crank means forms the angularly displaceable member.

In a preferred embodiment the operable interaction means provides operable interaction between latching and operation of a locking means in an external lever.

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 sectional plan view of a latch bolt assembly with a latch bolt I fully extended; Figure 2 is a sectional side view of the latch bolt assembly of Figure 1; Figure 3 is a sectional side view of the latch bolt assembly with the latch bolt restrained in a partly extended position; and Figure 4 is an isometric view from the front of the latch bolt assembly.

1 L- l.i -3- As shown in Figures 1 to 4, a deadlocking latch bolt assembly 1 includes a latch bolt housing 10 having two parallel spaced plates 11 and 12 extending rearwardly from the bolt housing and a front plate 13 by which the assembly is attached to a door. The housing has a rear wall 19 in which there is a slot 14 through which a connecting member 70 and a locking member 80 pass. At either end of the slot 14 there are shoulders 15 and 16 engageable by the locking member In the spaced plates 11 and 12 there are circular holes 17 in which a pivotally displaceable shaft 61iis situated and a pair of elongated slots 18 in which drive pins 51 are displaceable to facilitate sliding movement of the pins and the slide 50 which is supported between the spaced plates by the drive pins. An arm 64 of an angularly displaceable crank member 60 also supported between the spaced plates, preferably on the shaft 61, is engageable by a shoulder 52 of slide The drive pins protrude from each side of the parallel plates where they are engageable by drive means associated with an adjacent external lever assembly (not shown). Bolt operation is effected by the imparting of translation to the slide Thle shaft 61 may have a central axial rectangular aperture 62 in which a a spindle locates and in this case the shaft would have an abutment which is a a engageable by abutments on the crank member 60. The spindle links to a locking means in an external lever thereby providing operable coupling between the latch 0.0.00bolt and locking means; by this means inward bolt displacement causes the locking mreans to be actuated to an unlocked configuration.

Alatching bolt 30 as shown in Figure 4 has a protruding nose that includes a latching lever 40 on one side and auxiliary bolt 90 on the other. The bolt 25 kltching lever 40 and auxiliary bolt 90 art mounted to be relatively movable one to i:~i the others.

*0 As shown in Figure 1, the latching bolt 30 supported in the housing and 00 0 having a c' Atoured end has a recess 31 to accommodate the end of an arm 42 of the latch lever 40 so as to preclude an exposed concave recess between the latch lever and bolt. The latch lever is attached to the bolt by a pin joint 43 facilitating Spivotal displacement relative to the bolt. The latch lever also has a second arm 41 (hich is engageable with the inside edge of the front plate 13.

941108,p:\oper\rshDoor-lodcs.spe,3 Th~e bolt 30 is biased outwardly by spring The crank member 60 and the bolt are connected by the connecting member which is pin jointed to the crank member 60 and the bolt 30 by pin joints 63 and 32 both facilitating relative pivotal displacement. The joint at pin 32 also facilitates limited translational displacement via an elongated slot 72 in the connecting member 70 whereby some movement of the member 70 is possible without effecting the bolt. Pin joint 63 is on the opposite side of the shaft 61 from arm 64.

The connecting member 70 has, slightly displaced from the slot 72, an abutment 71 which is adjacent a leg 83 of the locking member 80 which is also pivotally supported by pin joint 32. This member has opposite the pivot point another leg 82 with a leading edge 81. Displaced from the pivot point, the locking member 80 has on one edge ramped shoulders 84 and 85 for engaging the shoulder of the back plate and oja the other edge a hooked shoulder 86 for engaging the shoulders 16 of the slot 14 in the housing rear wall 19, The locking member 80 is biased towards engagement of the shoulder 15 so that when the bolt is fully extended and the auxiliary bolt 90 held inwards by a strike plate the shoulder engages behind shoulder 15 to prevent the bolt being driven inwardly by end force.

If the bolt is partly extended the shoulder 84 may likewise engage behind shoulder Biasing occurs as a result of spring 33 acting on leg 82 through a slidable pin 34 which is situated between the spring and leg.

A. As shown in Figure 1, the auxiliary bolt 90 is biased outwardly by spring 91 and, as shown in Figure 2, has rearwardly a shoulder 92. The leading edge 81 of the locking member 80 is engageable by this shoulder so when the auxiliary bolt is not held inwardly by a strike plate the spring bias causes the auxiliary bolt 90 to engage the locking member leading edge 81 and pivot the member in a direction where the hooked shoulder 86 may engage the slot shoulder 16.

Movement of the connecting member 70 inwardly also causes the locking member to pivot in a direction where the hooked shoulder 86 may engage the slot shoulder 16. Shoulder 71 of the connecting member engages leg 83 of the locking member and the limited movement of the connecting member facilitated by the slot 72 is sufficient to displace the locking member while not affecting the bolt.

In general, it is not essential that the connecting member 70 be pivotally 941108,p:\oper\rs,Door-locks.spe,4 joined at both ends as shown in Figures 1 to 3. The crank member must be able to retract the connecting member 70 and the connecting member should have a small amount of free movement relative to the bolt. However, when the bolt 30 is required to actuate the spindle and locking means, the joint between the crank member and connecting member must not permit relative displacement in either longitudinal direction and a pin joint is a simple means of achieving this.

The bolt operating means includes the crank member 60 which is operably engageable with the slide 50. Typically the external lever has a lock actuating means in the form of a conventional locking cylinder and a locking means such as a clutch which may be selectively actuated to prevent the bolt from being actuated by the lever. The spindle originating in and engageable with the locking means passes through the rectangular recess 62 in the shaft 61 with which it is engageable.

The shaft is engageable with the crank member so that during inward movement of the bolt the shaft may be pivotally displaced and the spindle likewise pivotally displaced.

THE LOCKSET IN USE 0* When the bolt is fully extended within a strike plate, the shoulder 85 of the 1V locking arm is engaged with the shoulder 15 of the back plate, the slide 50 is unrestrained and the auxiliary bolt 90 would be held inwardly by the striker plate.

Consider the case of the lever of the external lever set being unlocked and free to operate the lock bolt.

Rotation of the unlocked lever by means of an interspaced drive mechanism 0 0 causes the slide 50 to translate. Shoulder 52 of the slide drives forward arm 64 of the crank member 60 so that the pivot point 63 is drawn inwardly.. The connecting *000 member moves fractionally to engage the leg 83 of the locking member 80 and a 0 little further displacement pivots the shoulder 85 of the locking member 80 out of *000 the engagement with the shoulder 15 of the backplate. Further displacement of the connecting member draws the bolt inward while holding the locking member towavds shoulder 16.

When the bolt has been fully retracted and the bolt moved out of the engagement with the strike plate the auxiliary bolt shoulder 92 moves into 9411D8,p.-oper~rsh,Door-locks.spe,5 -6engagement with the leading edge of the locking member to also hold it towards the shoulder 15 against the bias of spring 33.

As the lever is rotated in the opposite direction the slide 50 is driven inwardly by the crank member 60 which is driven by the bolt which is in turn driven by spring 35. The assembly is driven until the hooked shoulder 86 engages the shoulder 16 at which point the bolt is restrained against further outward displacement. This configuration is the normal latching position and is shown in Figure 3.

When the door is closed and the latch bolt strice against the strike plate the bolt 30 is driven inwardly, the auxiliary bolt 90 is restrained by the strike plate so that shoulder 92 no longer drives the locking member towards shoulder 16, the connecting member exerts no force and so the bolt is driven fully out with the locking member 80 biased by spring 33 to engage the shoulder 15. When the bolt is fully out shoulder 85 engages shoulder 15 to deadlock the bolt.

Latch levers are well known but they generally have a gap between the lever and the latch bolt and if material is forced into this concave recess latching is 0~ 00 prevented. This leaves the lock prone to vandalism. The lock of this embodiment provides a latch lever 40 where the exterior form of the assembly comprising the latch lever and the latch bolt is convex to preclude an external concave recess ;:20 between the lever and bolt.

0 Locks having latch bolts of extended length are well known but they often do not function well and have operational deficiencies. Such locks comprising a pair of external lever assemblies and a deadlocking latch bolt of extended throw commonly include a drive shaft which interconnects the lever assemblies and engages an operational member in the latch bolt assembly. Rotation of an exterior lever causes the drive shaft to rotate and operate the bolt. This type of lock suff from deficiencies resulting from the lever assemblies not being able to 00 independently operate the bolt. A particular deficiency is the inability of bolt inward movement during latching to effect the locking means in an external lever assembly since the drive shaft spatially precludes a spindle. The lock of this embodiment overcomes this deficiency by providing an independent 'spindle engaging with and p~i ;ing through the latch bolt assembly and interconnecting the

.A

1 ~I/941108,p:\oper~mhDoor-locksspc6 -7lock actuating means in each lever assembly.

in other common locks independent lever operation and a spindle are employed but these locks generally do not accommodate bolts of extended length.

These locks employ a displaceable carriage which couples directly to the latch bolt.

00 0 0 bo 0 o0 009p 0 0 9.00 000 1 4 llO,p:\oper\Dooro. ps,7

Claims (8)

1. A lock comprising a casing, a deadlocking latch bolt of extended length supported within the casing and displaceable relative to the casing between fully extended, partially extended, and retracted positions, biasing means for urging the latch, bolt towards the extended position, latch bolt actuating m--ans for displacing the latch bolt towards said retracted position, said actuating means including a connecting arm engageable with said latch bolt and crank means engageable with said connecting arm, a strike plate engageable by the latch bolt, and latching means operative to cause displacement of the bolt towards its retracted position from any extended position consequent on interaction between the lock and strike plate, said latching means comprising a ramped portion of the latch bolt and a lever carried *0 by the latch bolt and engage able with the strike plate during latching to effect of the bolt towards its retracted position. 0

2. A lock according to claim 1, wherein the lever is supported within a recess 0 in the latch bolt.

3. A lock according to claim 1 or claim 2, further comprising means for reL!' "ably retaining the bolt in its partially extended position and comprising releasable abutment means to restrain the latch bolt from being displaced to the fully extended position by the biasing means.

4. A lock according to &a1y one of the preceding claims, further compr"~ng means for linking the latch bolt to an external lever to provide interaction 0~. externai lever.

A lock according to claim 4, wherein the linking means comprises a spindle member rotatable upon retraction of the bolt.

6. A lock according to claim 5, wherein the spindle member is engaged witli a Al t~j shaft which supports the crank means, sald crank means being displaced during 941206,p:\oper\rs,Door-locks.spe,8 L- -9- retraction of the bolt.

7. A lock according to any one of the preceding claims, wherein deadlocking of the bolt in its fully extended position is effected by means of a displaceable locking arm.

8. A lock according to claim 7 when dependent on claim 3, wherein the locking arm includes the abutment means. Dated this 9th day of November, 1994. JOHN RUSSELL WATTS By his Patent Attorneys: DAVIES COLLISON CAVE 04 0 0 a a 00 a0 a t 941108,p:\oper\rhDoorldcs.spe,9