AU2024203492A1

AU2024203492A1 - A Lock

Info

Publication number: AU2024203492A1
Application number: AU2024203492A
Authority: AU
Inventors: Simon Butt; Frankie Ngan
Original assignee: TNBT Holdings Pty Ltd
Current assignee: TNBT Holdings Pty Ltd
Priority date: 2019-07-25
Filing date: 2024-05-24
Publication date: 2024-06-13
Also published as: AU2022201974A1; AU2020207887A1

Abstract

Disclosed herein is a lock.

Description

A LOCK

Technical field

The disclosure herein generally relates to locks, and specifically but not exclusively to locks that have hold back.

Background

Some locks, examples of which include but are not limited to some latches, night latches and some rim locks, have an outwardly biased ("sprung") latch bolt. An example of such a lock has a latch bolt operationally coupled to a rotatable handle for a user to retract the latch bolt. Examples of rotatable handles include but are not limited to a knob and a lever. The example lock has a self-latching function. When a door having the example lock attached closes, the outwardly biased latch can automatically enter a corresponding latch receiver on an adjacent structure to lock the door, without the user having to operate the lock. This can result in lock out. Examples of adjacent structures include but are not limited to doorjambs, walls, or posts. is Examples of latch receivers include but are not limited to a latch keeper and a strike plate.

The self-latching function of the example lock is not always desired. The user may wish to temporarily disable the self-latching function, for example during a short period in which the user expects to pass many times through a doorway of the door, or during the day time for doors that are heavily used during the day. Some rim locks and night latches have a mode in which a latch bolt is held within a lock housing, which is known in the art as hold back. The user can activate hold back in the example lock by rotating the rotatable handle past a retracted latch bolt position to a latch bolt hold back position, at which the latch bolt is held within the housing. The user can cancel hold back by counter-rotating the rotatable handle.

Summary

Disclosed herein is a lock. The lock comprises a latch bolt outwardly biased and a latch bolt carriage operationally coupled thereto, wherein the latch bolt carriage is movably mounted for movement thereof between a first position wherein the latch bolt is extended and a second position wherein the latch bolt is withdrawn. The lock comprises an actuator rotationally mounted and operationally coupled to the latch bolt carriage for withdrawing the latch bolt and rotatable to a holdback position wherein the latch bolt carriage is arrested in the second position.

The lock comprises a stop movable to a stop position whereat the stop is arranged to interfere with rotation of the actuator to the holdback position.

In an embodiment, the actuator comprises a cam and the stop when at the stop position is arranged to interfere with rotation of the cam to the holdback position.

In an embodiment, the actuator comprises a hand operable actuator and the stop when at the stop position is arranged to interfere with rotation of the hand operable actuator to the holdback position.

In an embodiment, the actuator and the latch bolt carriage cooperate to realisably retain the latch bolt carriage when the actuator is at the holdback position.

In an embodiment, the actuator is clockwise rotatable to the holdback position and counter clockwise rotatable to another holdback position wherein the latch bolt carriage is arrested in the second position, and the stop is movable to another stop position whereat the stop is arranged to interfere with counter clockwise rotation of the actuator to the holdback position. The actuator and the latch bolt carriage may cooperate to realisably retain the latch bolt carriage when the actuator is at the other holdback position.

Disclosed herein is a lock. The lock comprises a latch bolt outwardly biased and a latch bolt carriage operationally coupled thereto, wherein the latch bolt carriage is movably mounted for movement thereof between a first position wherein the latch bolt is extended and a second position wherein the latch bolt is withdrawn. The lock comprises a hand operable actuator and a cam rotatable by operation of the hand operable actuator to a clockwise rotation position and a counter clockwise rotation position, the cam being operationally coupled to the latch bolt carriage to inwardly move the latch bolt carriage such that the latch bolt carriage is at the second position when the cam is at either one of the clockwise rotation position and the counter clockwise rotation position, wherein the cam and the latch bolt carriage cooperate to realisably retain the latch bolt carriage when the cam is at either one of the clockwise rotation position and the counter clockwise rotation position. The lock comprises a cam rotation stop that is movable between a stop position wherein the cam rotation stop is arranged to interfere with rotation of the cam into one of the clockwise rotation position and the counter clockwise rotation position, and another stop position wherein the cam rotation stop is arranged to interfere with rotation of the cam into the other one of the clockwise rotation position and the counter clockwise rotation position.

In an embodiment, the cam comprises a first outward extension and a second outward extension, wherein the cam rotation stop when at the stop position is arranged to interfere with rotation of the cam into one of the clockwise rotation position and the counter clockwise rotation position by contact with the first outward extension, and the cam rotation stop when at the other stop position is arranged to interfere with rotation of the cam into the other one of the clockwise rotation position and the counter clockwise rotation position by contact with the second outward extension. The first outward extension and the second outward extension may be spaced apart.

In an embodiment, the cam rotation stop is slidable between the stop position and the other stop position.

In an embodiment, the cam rotation stop comprises a first stop surface and a second stop surface spaced apart from the first stop surface wherein when the cam rotation stop is in the stop position the first stop surface is arranged to interfere with the rotation of the cam into one of the clockwise rotation position and the counter clockwise rotation position, and when the cam rotation stop is in the other stop position the second stop surface is arranged to interfere with the rotation of the cam into the other one of the clockwise rotation position and the counter clockwise rotation position.

An embodiment comprises a housing configured to have the cam rotation stop fastened thereto when the cam rotation stop is in the stop position and in the other stop position.

In an embodiment, the cam rotation stop is movable between the stop position, the other stop position and yet another stop position wherein the cam rotation stop is arranged to interfere with rotation of the cam into either one of the clockwise rotation position and the counter clockwise rotation position.

An embodiment comprises a housing configured to have the cam rotation stop fastened thereto when the cam rotation stop is in any one of the stop position, the other stop position and the yet other stop position.

In an embodiment, the cam rotation stop is rotationally mounted and is rotatable between the stop position and the other stop position.

In an embodiment, the cam rotation stop comprises a first stop surface and a second stop surface wherein when the cam rotation stop is in the stop position the first stop surface is arranged to interfere with the rotation of the cam into one of the clockwise rotation position and the counter clockwise rotation position, and when the cam rotation stop is in the other position the second stop surface is arranged to interfere with the rotation of the cam into the other one of the clockwise rotation position and the counter clockwise rotation position.

In an embodiment, the cam rotation stop is rotatable between the stop position, the other stop position and the yet other stop position wherein the cam rotation stop is not arranged to interfere with rotation of the cam into either one of the clockwise rotation position and the counter clockwise rotation position.

An embodiment comprises a housing configured to have the cam rotation stop fastened thereto when the cam rotation stop is in the stop position, the other stop position and a yet another stop position.

An embodiment comprises a housing defining a cam rotation stop receiver at each of the stop position and the other stop position.

In an embodiment, the housing defines an aperture at each of the stop position and the other stop position for receiving the cam rotation stop.

In an embodiment, the cam rotation stop comprises an insert.

In an embodiment, the cam defines a first notch in which a first cam follower is releasably retained when the cam is in the clockwise rotation position and defines a second notch in which a second cam follower is releasably retained when the cam is in the counter clockwise position.

In an embodiment, the latch bolt carriage comprises the first cam follower and the second cam follower at one end of the latch bolt carriage and the latch bolt attached to another end of the latch bolt carriage.

In an embodiment, the latch bolt carriage comprises a first movably mounted part comprising the one end of the latch bolt carriage and a second movably mounted part coupled by a sliding joint to the first movably mounted part.

In an embodiment, the latch bolt carriage is attached to the latch bolt.

Disclosed herein is a lock. The lock comprises a latch bolt outwardly biased and a latch bolt carriage operationally coupled thereto, wherein the latch bolt carriage is movably mounted for movement thereof between a first position wherein the latch bolt is extended and a second position wherein the latch bolt is withdrawn. The lock comprises an actuator rotationally mounted and operationally coupled to the latch bolt carriage for withdrawing the latch bolt and rotatable to a holdback position wherein the latch bolt carriage is arrested in the second position. The lock comprises a stop receiver at a stop position for receiving a stop that when so received is arranged to interfere with rotation of the actuator to the holdback position.

In an embodiment, the lock comprises the stop. The stop may comprise an insert.

Disclosed herein is a method of reconfiguring a lock defined by any one of the preceding, the method comprising moving a cam rotation stop of the lock between the first stop position and the second stop position.

Any of the various features of each of the above disclosures, and of the various features of the embodiments described below, can be combined as suitable and desired.

Brief description of the figures

Embodiments will now be described by way of example only with reference to the accompanying figures in which:

Figures 1 and 2 show a front exploded view and a rear exploded view respectively of an embodiment of a lock.

Figures 3 to 16 show rear isometric and elevational views of the lock of figure 1 with a back plate removed.

Figures 17 to 19 show various isometric and rear elevational views into an emptied cavity

of the lock of figure 1.

Figure 20 shows a detailed elevational back view of a cam of the lock of figure 1.

Figures 21 shows a rear exploded view of another embodiment of a lock.

Figures 22 to 30 show rear elevational views of the lock of figure 21.

Figures 31 - 39 shows a rear elevation views of another embodiment of a lock.

Description of embodiments

Figures 1 and 2 show a front exploded view and a rear exploded view respectively of an embodiment of a lock in the form of a rim lock, specifically a night latch, the lock being generally indicated by the numeral 10. Figures 1 and 2 include an optional lock mounting plate 11. In use, the mounting plate 11 is fastened to a face of a door and adjacent to the swingable edge thereof, and the lock 10 is fastened to the mounting plate 11.

The lock 10 comprises a latch bolt 12. The latch bolt 12 is outwardly biased by the action of biasing elements in the form of torsion spring 14 and compression spring 16. The outward direction is indicated by arrow 13 in figure 1. The distal end 15 of the latch bolt 12 can enter and leave the housing 30 via lock bolt aperture 60 defined by the housing 30. Figures 3 to 16 show rear isometric and elevational views of the lock 10 with a back plate 38 removed from housing 30, revealing the latch bolt 12 and lock mechanism 40 disposed in the housing 30, the lock mechanism 40 being in various states. As best seen in figures 3 and 4, the torsion spring 14 is mounted on a torsion spring boss 54 tensioned. Figures 17 to 19 show various isometric and rear is elevational views into an emptied cavity 64 defined by the housing 30 to reveal a compression spring receiving cavity 58 defined by the housing 30. The compression spring 16 is disposed in the compression spring receiving cavity 58 compressed.

The lock 10 comprises a latch bolt carriage 18. The latch bolt 12 is attached to one end 20 of the latch bolt carriage 18. The latch bolt carriage 18 is attached to the latch bolt 12 by friction fitting the latch bolt 12 to the end 20 of the latch bolt carriage 18. The latch bolt carriage 18 is slidingly mounted between guide rails 66 attached to the housing 30 for movement of the latch bolt carriage 18 between a first position wherein the latch bolt 12 is extended (figures 3 and 4) and a second position wherein the latch bolt is withdrawn (figures 5, 6, 9, 10). One end of the compression spring 16 is in pushing contact with the housing 30 and the other end is in pushing contact with a spring engaging tab 62 of the latch bolt carriage 18 for outwardly biasing the latch bolt carriage and so also the latch bolt 12. One end of the torsion spring 14 contacts the housing 30 and the other end of the torsion spring 14 contacts an inwardly facing surface 56 of the latch bolt carriage 18.

The lock 10 comprises a hand operable actuator 42, which in this embodiment is a handle in the form of a knob, and an actuator comprising a cam 44 rotatable by operation of the handle 42. In the context of the present document, a hand operable actuatoris the part of the lock that a user can actuate to withdraw the latch bolt 12. The hand operable actuator is at the front face of housing 30, and is actuated by hand rotation of the hand operable actuator around a hand operable actuator axis. The cam 44 is spin riveted to the handle 42, however in an alternative embodiment it may be threaded and engaged with a spindle engaged with the handle 42, or maybe operationally coupled in generally any suitable way. In figures 3 and 4, the cam 44 is shown in a neutral cam rotational position, wherein the latch bolt 12 is extended. The handle 42 can be rotated in either one of a clockwise direction and a counter clockwise direction, causing rotation of the rotationally mounted cam 44 in the same direction. The cam 44 can be rotated to a clockwise rotation position shown in figures 5 and 6. The cam 44 can also be rotated to a counter clockwise rotation position shown in figures 9 and 10.

The cam 44 is operationally coupled to the latch bolt carriage 18 to inwardly move the latch bolt carriage 18 such that the latch bolt carriage 18 is at the second position (figures 5,6,9,10) when the cam is at either one of the clockwise rotation position (figures 5,6) and the counter clockwise rotation position (figures 9,10). As best seen in figures 3 and 4, the cam 44 comprises first and second cam elements 68,70 that are followed by first and second cam followers 72,74 of the latch bolt carriage 18. Figure 20 shows a detailed elevational back view of the cam 44. The first cam element 68 and second cam element 70 are in the form of circumferentially orientated tabs at opposite ends of a peripheral arcuate portion 78 of the cam 44, each of which terminate in a rounded end 80,82.

When the latch bolt carriage 18 is at the second position, the cam 44 and the latch bolt carriage 18 cooperate to realisably retain (that is, releasably holding back) the latch bolt carriage 18 when the cam 44 is at either one of the clockwise rotation position and the counter clockwise rotation position. The cam 44 defines a first notch 46 in which the first cam follower 72 of the lock bolt carriage 18 is releasably retained when the cam 44 is in the clockwise rotation position, as shown in figures 5 and 6. The cam 44 defines a second notch 50 in which the second cam follower 74 of the lock bolt carriage 18 is releasably retained when the cam 44 is in the counter clockwise position, as shown in figures 9 and 10.

Retention (that is, the holding back) of the latch bolt carriage 18 by cam 44 is now described in further detail. As best seen in figure 20, notches 46,50 are defined in an arcuate portion 78 thereof. One of the cam followers 72,74 is releasably retained in one of the notches 46, 50 when the latch bolt carriage 18 is in the second position, having been moved by rotation of cam 44. Retention works as follows. When the latch bolt carriage 18 is moved outwardly, the arcuate portion 78 and the latch bolt carriage 18 jamb, preventing further rotation of the cam 24, and so outward movement of the cam follower 74 is stopped. The cam 24, however, can be rotated to move the arcuate portion 70 and the relevant projecting tab 68,70 out of engagement with the relevant cam follower 72,74. A notch 46,50 is at each end of the arcuate portion 78 and so hold off can be activated when the handle 42 is rotated in clockwise and counter clockwise directions. In an alternative embodiment, a latch may be used instead of the notched cam 24, the latch being disengaged by another cam or linkage. Alternatively, separate cams may be used for actuating the latch bolt carriage 18 and the retention function.

The latch bolt carriage 18 comprises an elongated plate of metal comprising the cam followers 72,74 at one end of the plate of metal. The cam followers 72,74 are out of the plane of the body of the latch bolt carriage 18. The latch bolt carriage 18 is die cast, however it alternatively may be formed by punching and bending a sheet of metal.

The lock 10 has a cam rotation stop 84. The cam rotation stop 84 is movable between a plurality of stop positions. Figures 3, 4, 7, 8, 9 and 10 show the cam rotation stop 84 in a first stop position wherein the cam rotation stop 84 is arranged to interfere with rotation of the cam 44 into the clockwise rotation position. The cam 44 has a first outward extension 90. The cam rotation stop 84 is arranged when in the first stop position to interfere with rotation of the cam 44 into the is clockwise rotation position by contact with the first outward extension 90.

Figures 5, 6, 11, 12 show the cam rotation stop 84 in a second stop position, wherein the cam rotation stop 84 is arranged to interfere with rotation of the cam 44 into the counter clockwise rotation position. The cam 44 has a second outward extension 92. The cam rotation stop 84 is arranged when in the second stop position to interfere with rotation of the cam 44 into the counter clockwise rotation position by contact with the second outward extension 92.

In alternative embodiments, the stop position is positioned such that the stop when at the stop position is arranged to interfere with rotation of the hand operable actuator 42 to the holdback position. Alternatively or additionally, the stop position is positioned such that the stop when at the other stop position is arranged to interfere with rotation of the hand operable actuator 42 to the other holdback position.

In this but not all embodiments, the cam rotation stop 84 can be translated with a sliding movement along an elongated cam rotation stop seat 102 within the housing 30, or alternatively the cam rotation stop 84 can be removed from a cam rotation stop seat 102 and reseated at the cam rotation seat 102 at another one of the plurality of cam rotation stop positions.

The first outward extension 90 and the second outward extension 92 each comprise optional flat ends 94,96 configured to be in parallel contact with the cam rotation stop 84, which may generally provide a relatively greater contact area and consequently relatively reduced contact pressure. The first outward extension 90 and the second outward extension 92 are spaced apart, being at different angular positions of the body 98 of the cam 44. The cam 44 has mirror symmetry about a line 100 intermediate the first outward extension 90 and the second outward extension 92, however it need not be.

One of the plurality of stop positions is a third stop position, as shown in figures 13, 14, 15, 16. When the cam rotation stop 84 is in the third position, the cam rotation stop 84 is arranged to interfere with rotation of the cam 44 into either one of the clockwise rotation position and the counter clockwise rotation position. As best seen in figure 2, the cam rotation stop comprises spaced apart stop members 104,106 spaced apart by void 108. When the cam rotation stop 84 is in the third position, the first and second outward extensions 90,92 cannot enter the void 108 without contacting the stop member 104,106 when the cam 44 is rotated to the clockwise rotation position and the counter clockwise rotation position, disabling holdback mode in lock 10.

As described above, the lock 10 can be configured such that holdback mode cannot not be is activated by one of, or both of, a clockwise rotation of the handle 42 by a user or a counter clockwise rotation of the handle 42 by a user. The handedness of the lock can consequently be configured. Removal of the cam rotation stop 84 enables rotation of the cam 44 into the clockwise and counter clockwise rotation positions.

The housing 30 is configured to have the cam rotation stop 84 fastened thereto when the cam rotation stop is in any one of plurality of stop positions. Fastener 110 in the form of a screw may be inserted in aperture 112 of the cam rotation stop 84 and engaged by any one of the internally threaded cylindrical walls 114, 116 and 118 (figure 17) of the housing 30.

The latch bolt carriage 18 comprises a first part 22 that is slidingly mounted within the housing 30 and comprising the one end 20 of the latch bolt carriage 18. The latch bolt carriage comprises a second part 24 slidingly mounted within the housing 30. The second part 24 is coupled to the first part 22 by a lost motion joint formed by boss 26 being received by slot 28. The two-part carriage 18 and sliding joint enable operation of an optional anti-carding mechanism comprising anti-carding snib 30, anti-carding snib biasing spring 34, catch 38, and catch biasing spring 36. Anti carding snib 32 can be disposed in snib aperture 120 of the housing 30.

The cam 44 is operationally coupled to the rotationally mounted handle 42, which is in the form of a knob.

The latch bolt carriage 18 can also be moved by rotation of another cam 134 operationally coupled via another spindle 138 in the form of a flat bar to a lock cylinder 136. Key operation of the lock cylinder 136 withdraws the lock bolt 12 into the housing 30. The other cam 134 is rotationally mounted to the back plate 38 with a grommet 138 that has its rim deformed to fasten it in place.

In use, the mounting plate 11 is fastened to a face of a door - generally the inside face - using fasteners in the form of screws or bolts, or generally any suitable form of fastening, for example a rivet or adhesive. The lock 10, in this embodiment specifically the housing 30, and the mounting plate 11 are cooperatively configured for fastening the housing 30 to the mounting plate 11. The housing 30 is configured to slidingly receive longitudinal tags 122 and receive therein end flanges 124. Mounting plate fasteners (not shown) are inserted in fastener apertures 126 of the housing 30 and engage threads 128 at the end flange 124. The lock's internal assembly can be accessed by removing the mounting plate fasteners, slidingly disengage the tags 122, separating the lock 10 from the mounting plate 11, and removing back plate screws 130.

Figure 21 shows a rear exploded view of another embodiment of a lock 200. Parts similar or identical in form and/or function to those in figures 1-20 are similarly numbered. Like lock 10, the lock 200 can be configured such that holdback cannot not be activated by one of, or both of, a clockwise rotation of the handle 42 by a user or a counter clockwise rotation of the handle 42 by a user. Figures 22 to 30 show rear elevational views of the lock 200 with the back plate 38 removed, and a rotationally mounted cam rotation stop 284 a first position (figures 22 to 24), a second position (figures 25 to 27) and a third position (figures 28 to 30). The cam rotation stop 284 is rotatable between the first stop position, the second stop position and the third stop position. The cam rotation stop can be and subsequently fastened into position with a fastener in the form of a screw, for example, or adhesive.

The cam rotation stop 284 comprises a first stop surface 202 and a second stop surface 204. When the cam rotation stop 284 is in the first position the second stop surface 204 is arranged to interfere with the rotation of the cam 44 into one of the clockwise rotation position and the counter clockwise rotation position. When the cam rotation stop 284 is in the second position the first stop surface 204 is arranged to interfere with the rotation of the cam 44 into the other one of the clockwise rotation position and the counter clockwise rotation position. In the third rotation position, third and fourth surfaces 206,208 respectively are arranged to interfere with rotation of the cam 44 into the clockwise rotation position and the counter clockwise rotation position.

Figures 31 - 39 shows a rear elevation views of another embodiment of a lock 300 with a back plate removed. Parts similar or identical in form and/or function to those in figures 1 to 20 are similarly numbered. Lock 300 can be configured such that holdback cannot not be activated by one of, or both of, a clockwise rotation of the handle or a counter clockwise rotation of the handle. Lock 300 can also be configured such that holdback can be activated by both clockwise rotation and counter clockwise rotation of the handle. The cam rotation stop 384 comprises a fastener in the form of a screw, which is shown in a first position in figures 31 to 33, and in a second position in figures 34 to 36. Two cam rotation stops 384, 385 are shown at each of the first position and the second position in figures 37 to 39. The fasteners 384,385 can be inserted or removed as required.

The housing 30 defines a plurality of cam rotation stop receivers in the form of internally threaded walls defining apertures at each of the first stop position and the second stop position for receiving the fasteners 384,385. In alternative embodiments, however, the cam rotation stops 384,385 may take the form of an insert, examples of which include a peg, clip, bolt, pin, rod is which are received by an aperture. Alternatively, the cam rotation stop may take the form of a sleeve that is received by a pin attached to the housing at thefirst position and the second position.

Now that embodiments have been described, it will be appreciated that some embodiments may have some of the following advantages:

• Either one of the two different holdback modes can be selectively blocked, to differently hand the lock. • A locksmith can replace four sets of stock with various fixed hold back modes with one set of stock. • A user may reconfigure the lock after it is installed as the need arises.

Variations and/or modifications may be made to the embodiments described without departing from the spirit or ambit of the invention. For example:

• There may be only one latch bolt biasing element of generally any suitable form, examples of which include but are not limited to a torsion spring, a compression spring, an extension spring, and a resilient pad (e.g. a resilient foam pad). Alternatively, there may be more than two latch bolt biasing elements of generally any suitable form. • The latch bolt carriage may be one piece, or may comprise more than two pieces. A one piece latch bolt carriage may suitable for locks without anti-carding, for example.

• The latch bolt may be attached to the latch bolt carriage by at least one fastener in the form of a rivet or screw, or alternatively or additionally at least one of a weld, a braze, adhesive or generally by any suitable means. • The latch bolt may be integral with the latch bolt carriage.

• The handle may take the form of a knob, lever or generally any suitable form. • There may be a second cylinder lock at the handle, which may allow deadlocking. • The lock may take the form of a mortice lock, or generally any suitable form of lock. • The anti-carding mechanism is optional and may not be present in some embodiments. • The latch bolt carriage may be mounted on at least one guide rail.

• The latch bolt carriage may not be slidingly mounted. For example, the latch bolt carriage in an alternative embodiment rolls on bearings. In an alternative embodiment, another cam is intermediately coupled between the latch bolt carriage (as it is in the illustrated embodiments) and the latch bolt such that the latch bolt is rotated (i.e. swung) into and out of the cavity. • The handle and the cam may be coupled by an idler gear, for example, such that they rotate in opposite directions. • While in present embodiments the guide rails are integral with the housing, they are in an alternative embodiment distinguishable from the housing and attached with fasteners, a welds, a braze, an adhesive or generally any suitable means. • An alternative embodiment does not have a mounting plate, but does have perforated lugs attached to the housing 14 for door fasteners. Generally, any suitable fastening system may be used to fasten the lock 10 to the door. • An alternative embodiment does not have the third position for the cam rotation stop 84. • Fasteners other than screws may be used as suitable and appropriate, for example a bolt, rivet or generally any suitable form of fastener. Welds or adhesives, for example may also be used as suitable and appropriate. • The latch bolt may not be attached to the carriage, but may cooperate to engage with it (e.g. using pins, pin apertures etc). • There may only be two stop positions, so that holdback mode can only be disabled for rotation of the handle in one direction. For example, in some alternative embodiments, one of the spaced apart stop members 104, 106 may be omitted, cam rotation stop 284 may be reconfigured to interfere when in only one position, or there may only be a single cam stop receiver for cam rotation stop 384.The lock mechanism may use a rack and pinion, for example, instead of one or more cams to move the latch bolt, and a rack latching mechanism may be used for hold back. The movable stops may be for interfering with translation of the rack, or rotation of the pinion.

The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. Reference to a feature disclosed herein does not mean that all embodiments must include the feature.

Prior art, if any, described herein is not to be taken as an admission that the prior art forms part of the common general knowledge in any jurisdiction.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, that is to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims

1. A lock with a holdback function, the lock comprising:

a latch bolt outwardly biased and a latch bolt carriage operationally coupled thereto, wherein the latch bolt carriage is movably mounted for movement thereof between a first position wherein the latch bolt is extended, and a second position wherein the latch bolt is withdrawn; an actuator rotationally mounted to and adapted to drive the latch bolt carriage to move between the first and second positions, the actuator being rotatable further to a holdback position wherein the latch bolt carriage is arrested in the second position; a stop adapted to disable the holdback function, the stop being movable to a stop position whereat the stop is arranged to interfere with and prohibit rotation of the actuator to the holdback position.

is

2. A lock defined by claim 1 wherein the actuator comprises a cam and the stop when at the stop position is arranged to interfere with rotation of the cam to the holdback position.

3. A lock defined by any one of the preceding claims wherein the actuator comprises a hand operable actuator and the stop when at the stop position is arranged to interfere with rotation of the hand operable actuator to the holdback position.

4. A lock defined by any one of the preceding claims wherein the actuator and the latch bolt carriage cooperate to releasably retain the latch bolt carriage when the actuator is at the holdback position.

5. A lock defined by any one of the preceding claims wherein the actuator is clockwise rotatable to the holdback position and counter clockwise rotatable to another holdback position wherein the latchbolt carriage is arrested in the second position, and the stop is movable to another stop position whereat the stop is arranged to interfere with counter clockwise rotation of the actuator to the another holdback position.

6. A lock defined by claim 5 wherein the actuator and the latch bolt carriage cooperate to releasably retain the latch bolt carriage when the actuator is at the another holdback position.

7. A lock with a holdback function, the lock comprising:

a latch bolt outwardly biased and a latch bolt carriage operationally coupled thereto, wherein the latch bolt carriage is movably mounted for movement thereof between a first position wherein the latch bolt is extended and a second position wherein the latch bolt is withdrawn;

a hand operable actuator and a cam rotatable by operation of the hand operable actuator to a clockwise rotation position and a counter clockwise rotation position, the cam being operationally coupled and adapted to drive the latch bolt carriage to move the latch bolt carriage such that the latch bolt carriage is at the second position when the cam is at either one of the clockwise rotation position and the counter clockwise rotation position; the cam being rotatable further from the clockwise rotation position to a first holdback position and further from the counter clockwise rotation position to a second holdback position, respectively; wherein the latch bolt carriage is arrested in the second position; and

one or two cam rotation stops adapted to disable the holdback function, the one or two cam rotation stops being provided in either one or both of the first and second stop positions respectively; wherein the cam rotation stop is arranged to interfere with and prohibit rotation of the cam into the first holdback position when one of the cam rotation stops is in the first stop position and into the second holdback position when one or the other one of the cam rotation stops is in the second stop position.

8. A lock defined by claim 7 wherein the cam comprises a first outward extension and a second outward extension, wherein one of the cam rotation stops when at the first stop position is arranged to interfere with rotation of the cam into one of the clockwise rotation position and the counter clockwise rotation position by contact with the first outward extension, and the one of the cam rotation stops when at the other stop position is arranged to interfere with rotation of the cam into the other one of the clockwise rotation position and the counter clockwise rotation position by contact with the second outward extension.

9. A lock defined by claim 8 wherein the first outward extension and the second outward extension are spaced apart.

10. A lock defined by any one of the claims 7 to 9 wherein the one of the cam rotation stops is slidable between the first stop position and the other stop position.

11. A lock defined by any one of the claims 7 to 10 wherein the one of the cam rotation stops comprises a first stop surface and a second stop surface spaced apart from the first stop surface wherein when the one of the cam rotation stops is in the first stop position the first stop surface is arranged to interfere with the rotation of the cam into one of the clockwise rotation position and the counter clockwise rotation position, and when the one of the cam rotation stops is in the other stop position the second stop surface is arranged to interfere with the rotation of the cam into the other one of the clockwise rotation position and the counter clockwise rotation position.

12. A lock defined by any one of the claims 7 to11 comprising a housing configured to have the one of the cam rotation stops fastened thereto when the one of the cam rotation stops is in the first stop position and in the other stop position.

13. A lock defined by any one of the claims 7 to 12 wherein the one of the cam rotation stops is movable between the first stop position, the other stop position and yet another stop position wherein the one of the cam rotation stops is arranged to interfere with rotation of the cam into either one of the clockwise rotation position and the counter clockwise rotation position.

14. A lock defined by claim 13 comprising the housing configured to have the one of the cam rotation stops fastened thereto when the one of the cam rotation stops is in the first stop position, the other stop position and the yet another stop position.

15. A lock defined by any one of the claims 7 to 14 wherein the one of the cam rotation stops is rotationally mounted and is rotatable between the first stop position and the other stop position.

16. A lock defined by claim 15 wherein the one of the cam rotation stops comprises the first stop surface and the second stop surface wherein when the one of the cam rotation stops is in the first stop position the first stop surface is arranged to interfere with the rotation of the cam into one of the clockwise rotation position and the counter clockwise rotation position, and when the one of the cam rotation stops is in the other position the second stop surface is arranged to interfere with the rotation of the cam into the other one of the clockwise rotation position and the counter clockwise rotation position.

17. A lock defined by either one of claim 15 and claim 16 comprising the housing configured to have the one of the cam rotation stops fastened thereto when the one of the cam rotation stops is in the first stop position and in the other stop position.

18. A lock defined by either one claim 15 and claim 16 wherein the one of the cam rotation stops is rotatable between the first stop position, the other stop position and the yet another stop position wherein the one of the cam rotation stops is not arranged to interfere with rotation of the cam into either one of the clockwise rotation position and the counter clockwise rotation position.

19. A lock defined by claim 18 comprising the housing configured to have the one of the cam rotation stops fastened thereto when the one of the cam rotation stops is in the first stop position, the other stop position and the yet another stop position.

20. A lock defined by either one of claim 8 and claim 9 comprising a housing defining a cam rotation stop receiver at each of the first stop positions and the other stop position.

21. A lock defined by claim 20 wherein the housing defines an aperture at each of the first stop position and the other stop position for receiving the one of the cam rotation stops.

22. A lock defined by either one of the claim 20 and claim 21 wherein the one of the cam rotation stops comprises an insert.

23. A lock defined by any one of the claims 7 to 11 wherein the cam defines a first notch in which a first cam follower is releasably retained when the cam is in the clockwise rotation position and defines a second notch in which a second cam follower is releasably retained when the cam is in the counter clockwise position.

24. A lock defined by claim 23 wherein the latch bolt carriage comprises the first cam follower and the second cam follower at one end of the latch bolt carriage and the latch bolt attached to another end of the latch bolt carriage.

25. A lock defined by any one of the claims 7 to 24 wherein the latch bolt carriage comprises a first movably mounted part comprising the one end of the latch bolt carriage and a second movably mounted part coupled by a sliding joint to the first movably mounted part.

26. A lock defined by any one of the claims 7 to 25 wherein the latch bolt carriage is attached to the latch bolt.

27. A lock with a hold back function, the lock comprising: a latch bolt outwardly biased and a latch bolt carriage operationally coupled thereto, wherein the latch bolt carriage is movably mounted for movement thereof between a first position wherein the latch bolt is extended and a second position wherein the latch bolt is withdrawn; an actuator rotationally mounted to and adapted to drive the latch bolt carriage to move between the first and second positions, the actuator being rotatable further to a holdback position wherein the latch bolt carriage is arrested in the second position; a stop receiver at a stop position for receiving a stop which is adapted to disable the holdback function and which when so received is arranged to interfere with and prohibit rotation of the actuator to the holdback position.

28. A lock defined by claim 27 comprising the stop.

29. A lock defined by claim 28 wherein the stop comprises an insert.

is

30. A method of reconfiguring a lock defined by any one of the preceding claims, the method comprising moving a cam rotation stop of the lock between the first stop position and the second stop position.