AU2014202328B2 - A latch assembly - Google Patents

Abstract

A LATCH ASSEMBLY A latch assembly (20) including a casing (58), a latch bolt (40), an inner actuator (64), a locking means (50), a first key operated lock (66, 68), a first key control means (98) and an outer key operable actuator (34). The latch bolt (40) is mounted on the casing (58) for movement relative thereto between an extended latching position and a retracted opening position. The inner actuator (70) is operable from an inner side of the latch assembly (20) to retract the latch bolt (40) to the retracted opening position. The locking means (50) has an active condition, rendering the inner actuator (70) inoperable, and an inactive condition, in which the inner actuator (70) is operable. The first key operated lock (66, 68) is operable from the inner side of the latch assembly (20) and adapted to change the locking means (50) from the active condition to the inactive condition. The first key control means (98) is adapted to prevent the first key operated lock (66, 68) from changing the locking means (50) from the inactive condition to the active condition. The outer key operable actuator (34) is operable from the outer side of the latch assembly (20) and is adapted to change the locking means (50) from the active condition to the inactive condition, and retract the latch bolt (40) to the retracted opening position, and also change the locking means (50) from the inactive condition to the active condition. C"Cs cca

Description

Field of the Invention [0001] The present invention relates to a latch assembly.

[0002] The invention has been developed for use with a latch assembly for a door, and that has a deadlock function, and will be described hereinafter with reference to this application.

Background of the Invention [0003] The LOCKWOOD 001 (trade mark) latch assembly is well known and provides a deadlock function. This latch assembly has only a key controlled lock operable from the outside of the door. A pivoting handle or lever, and a second key operated lock associated with the handle/lever, is operable from the inside of the door. From the outside of the door, the correct key is required to retract a lock bolt and allow the door to be opened. This operation will also remove a deadlocked state if present. When this latch assembly is not deadlocked, rotation of the inner handle/lever will retract the lock bolt and allow the door to be opened. When this latch assembly is deadlocked, the inner key lock must first be operated before the inner handle/lever can retract the lock bolt and allow the door to be opened.

[0004] This latch assembly can only be placed in the deadlocked state by using the key to operate the inside lock. A disadvantage of this configuration is it allows a building occupant to activate deadlocking from inside a building. This can prevent or delay escape in an emergency if the correct key cannot be easily and quickly located and operated.

[0005] The LOCKWOOD 001 latch assembly also includes an indicator visible from the inner side of the door which displays green when not deadlocked and displays red when deadlocked.

A disadvantage of the indicator used is that it forms part of a complicated sub-assembly driven by the main latch assembly components, and thus adds to the cost and complexity of the latch assembly. Another disadvantage is the indicator can provide a false indication if the subassembly malfunctions.

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Object of the Invention [0006] It is an object of the present invention to substantially overcome or at least ameliorate one of more of the above disadvantages.

Summary of the Invention [0007] Accordingly, in a first aspect, the present invention provides a latch assembly including: a casing;

a latch bolt mounted on the casing for movement relative thereto between an extended latching position and a retracted opening position;

an inner actuator operable from an inner side of the latch assembly to retract the latch bolt to the retracted opening position;

a locking means having an active condition, rendering the inner actuator inoperable, and an inactive condition, in which the inner actuator is operable;

a first key operated lock operable from the inner side of the latch assembly and adapted to change the locking means from the active condition to the inactive condition;

a first key control means adapted to prevent the first key operated lock from changing the locking means from the inactive condition to the active condition; and an outer key operable actuator operable from the outer side of the latch assembly and adapted to change the locking means from the active condition to the inactive condition, and retract the latch bolt to the retracted opening position, and also change the locking means from the inactive condition to the active condition.

[0008] The first key control means is preferably a blocking means adapted to restrict the extent of pivotal movement of the first key operated lock.

[0009] The first key operated lock preferably includes a first cylinder body and a first barrel housed within the first cylinder body which is pivotally moveable relative to the first cylinder body by a correct key, the extent of the pivotal movement of the first barrel being restricted by the blocking means.

[0010] The latch assembly preferably further includes an outer driver, a cam and an inner driver, wherein the blocking means is associated with the inner driver.

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2014202328 30 Apr 2014 [0011] The first key control means is preferably a uni-directional torque transfer means adapted to restrict the torque transmission of the first key operated lock to one direction. The first key operated lock preferably includes a first cylinder body and a first barrel housed within the first cylinder body which is pivotally moveable relative to the first cylinder body by a correct key, the torque transmission from the first barrel being restricted by the uni-directional torque transfer means. The latch assembly preferably further includes an outer driver, a cam and an inner driver, wherein the uni-directional torque transfer means is associated with the inner driver.

[0012] In a second aspect, the present invention provides a latch assembly including: a casing;

a latch bolt mounted on the casing for movement relative thereto between an extended latching position and a retracted opening position;

an inner actuator operable from an inner side of the latch assembly to retract the latch bolt to the retracted opening position;

a detent having an active position, rendering the inner actuator inoperable, and an inactive position, in which the inner actuator is operable; and a visual condition indicator on, or forming part of, the detent which provides an indication on whether the detent is in the active position or the inactive position that is visible from an inner side of the latch assembly.

[0013] The visual condition indicator is preferably visible from the inner side of the latch assembly when the detent is in the active position and is not visible from the inner side of the latch assembly when the detent is in the inactive position. Alternatively, the visual condition indicator is not visible from the inner side of the latch assembly when the detent is in the active position and is visible from the inner side of the latch assembly when the detent is in the inactive position.

[0014] The casing preferably has an opening in an inner side thereof and the visual condition indicator is visible through the opening when the detent is in the active position and is not visible through the opening when the detent is in the inactive position.

[0015] The casing preferably has an opening in an inner side thereof and the visual condition indicator is not visible through the opening when the detent is in the active position and is visible through the opening when the detent is in the inactive position.

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2014202328 30 Apr 2014 [0016] The detent is preferably biased towards the active position.

[0017] The latch assembly preferably further includes a cam adapted to move the detent from the active position to the inactive position. The detent preferably abuts the cam.

[0018] The inner actuator preferably includes an opening into which the detent can enter, the opening and the detent each having ramp surfaces that contact each other when the detent is the inactive position, such that pivotal movement of the inner actuator drives the detent out of the opening, and that do not contact each other when the detent is the active position, such that pivotal movement of the inner actuator is prevented.

[0019] The latch assembly preferably further includes:

a first key operated lock operable from the inner side of the latch assembly and adapted to change the detent from the active position to the inactive position;

a first key control means adapted to prevent the first key operated lock from changing the locking means from the inactive condition to the active condition; and an outer key operable actuator operable from the outer side of the latch assembly and adapted to change the locking means from the active condition to the inactive condition, and retract the latch bolt to the retracted opening position, and also change the locking means from the inactive condition to the active condition.

Brief Description of the Drawings [0020] Fig. 1 is a perspective exploded view an embodiment of a latch assembly;

[0021] Fig. 2 is an inside perspective view of the latch assembly shown in Fig. 1, installed on a door;

[0022] Fig. 3 is an outside perspective view of the latch assembly shown in Fig. 1, installed on a door;

[0023] Fig. 4 is an upper perspective exploded view of components of the latch assembly shown in Fig. 1, demonstrating operation from outside;

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2014202328 30 Apr 2014 [0024] Fig. 5 is a side view of the latch assembly shown in Fig. 1, demonstrating locking from outside;

[0025] Fig. 6 is a side view of the latch assembly shown in Fig. 1, demonstrating unlocking from outside;

[0026] Fig. 7 is a side view of components of the latch assembly shown in Fig. 1, demonstrating door opening from outside;

[0027] Fig. 8 is a lower perspective exploded view of components of the latch assembly shown in Fig. 1, demonstrating unlocking from inside;

[0028] Fig. 9 is a side view of components of the latch assembly shown in Fig. 1, demonstrating unlocking from inside;

[0029] Fig. 10 is a side view of components of the latch assembly shown in Fig. 1, demonstrating door opening/bolt retraction from inside; and [0030] Fig. 11 is a side view of components of the latch assembly shown in Fig. 1, demonstrating anti-locking from inside.

Detailed Description of the Preferred Embodiment [0031] Fig. 1 shows an embodiment of a latch assembly 20 that includes an external key 22, an external lock cylinder 24, an external lock barrel 26 and a drive bar 28. The cylinder 24 mounts within a rim 30. The latch assembly 20 also includes a mounting bracket 32. The latch assembly 20 also includes a cam member 34, with a drive lug 36, a bolt cover 38, a bolt assembly 40 and a lever retaining plate 42. The latch assembly 20 also includes a torsion spring 44, a bolt drive member 46, a cam 48, a detent 50, a detent spring 52 and a detent roller 54. Fig.

also shows a housing 58, which is fastened to the mounting bracket 32 by a pair of screws 60, and a striker 62. Fig. 1 also shows an inner drive plate 64 associated with the internal barrel 66 of an internal cylinder 68. Finally, Fig. 1 shows an internal lever 70 and an internal key 72. The external key 22 and internal key 70 are usually, but not necessarily, coded the same.

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2014202328 30 Apr 2014 [0032] In this specification, the terms external, outside and outer are used interchangeably, as are the terms internal, inside and inner.

[0033] Figs. 2 and 3 respectively show the inside view and the outside view of the assembled latch assembly 20 mounted to a door 74. The assembly and mounting of the latch assembly 20 will be well understood by persons skilled in the art. Fig. 2 also shows that the housing 58 includes an opening or window 76, the purpose of which shall be explained in more detail below.

[0034] Fig. 4 shows the main components of the latch assembly 20 used in operating the latch assembly 20 from outside. Fig. 4 shows a drive socket 78 in the cam member 34. The cam member 34 also has a bolt retraction projection 80. Fig. 4 also shows that the cam 48 has a recess 82 and a cut out 84.

[0035] Fig. 5 shows that the housing 58 includes a recess 86 for housing the detent roller 54 and that the detent 50 includes a red-coloured indicator panel 90. Fig. 5 also shows that the lever 70 has a slot 88 and that the distal end of the detent indicator 50 includes a rounded nose 92 with a pair of angled sides 93 each leading into one of a pair of opposed parallel straight sides 94.

[0036] Referring to Figs 4 and 5, turning the key 22 clockwise drives the cam member 34 clockwise. As a result, the drive lug 36 on the cam member 34 turns the cam 48 clockwise until the recess 82 aligns with the nose 92 of the detent 50, as shown in Fig. 5. Under the force of the spring 52, the detent 50 is pushed through the slot 88 to engage with the lever 70. The cam 48 also pushes the roller 56 into the recess 86 of the housing 58. Both the detent 50 and the roller 54 engage the lever 70 with the housing 58, thus preventing the lever 70 from rotation. As a result, the latch assembly 20 is locked and the door 74 cannot be opened from the inside. Put another way, the lever 70 cannot be rotated to retract the bolt assembly 40, due to the engagement of the detent 50 within the slot 88. Fig. 5 also shows that, in the locked position, the coloured indicator panel 90 is aligned with the opening 76 in the housing 58 and is therefore visible through the opening 76 from inside. The panel 90 thus provides a visual indication that the latch assembly 20 is locked.

[0037] The unlocking of the latch assembly 22 from outside will now be described with reference to Figs. 4 and 6. To unlock the latch assembly 22 from outside, the external key 22 is rotated anti-clockwise, which drives the cam member 34 anti-clockwise. As shown in Fig. 6, the

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2014202328 30 Apr 2014 lug 36 on the cam member 34 drives the cam 48 anti-clockwise which pushes the detent 50 out of the recess 82. If the lever 70 is turned at this stage, the roller 54 will move inward and the detent 50 will move outward, thereby allowing turning of the lever 70 and unlocking the door 74. As the lever 70 is turned, one of the angled sides 93 of the detent 50 abuts the slot 88 in the manner of a ramp, thus pushing the detent 50 outwardly from engagement with the slot 88.

[0038] The opening of the door 74 from outside will now be described with reference to Fig. 4 and Fig. 7. Fig. 7 shows that the bolt assembly 40 includes a bolt frame 95, with a bolt track face 96, to which is mounted a bolt 97. Turning the external key 22 anti-clockwise drives the cam member 34 anti-clockwise through the drive bar 28. The bolt retraction projection 80 on the cam member 34 engages with the bolt track face 96 within the bolt assembly 40, thereby causing the bolt assembly 40 and thus the bolt 97 to be retracted. Once the bolt 97 has been retracted in this way, the door 74 can be opened.

[0039] Fig. 8 shows components of the latch assembly 20 utilised in unlocking the latch assembly 20 from inside. Fig. 8 shows that the inner drive plate 64 includes an anti-locking tab 98 and a drive lug 99 extending therefrom. Fig. 8 also shows that the bolt drive member 46 has a pair of protuberances 100 which join the bolt drive member 46 to the lever 70 by engaging in corresponding slots 88 and 101 (see Fig, 4).

[0040] As shown in Fig. 9, turning the internal key 72 clockwise drives the inner drive plate 64 clockwise. As a result, the drive lug 99 of the inner drive plate 64 turns the cam 48 clockwise to move the detent 50 out of the recess 82. This action also aligns a recess 102 with the roller 54. Once the cam 48 is positioned as shown in Fig. 6, the lever 70 is free to rotate and retract the bolt assembly 40 and the bolt 97.

[0041] The opening of the door 74, or retracting of the bolt 97, from inside will now be described with reference to Fig. 10. The door 74 is opened from the inside by turning the lever 70 in either direction. Once the cam 48 is in the unlocked position previously described, rotating the lever 70 in either the clockwise or anti-clockwise directions will cause a projection 80 on the bolt drive member 46 to abut with the bolt track face 96, as shown in Fig. 10. Further rotation of the lever 70 fully retracts the bolt 97. The door 74 can be opened once the bolt 97 is fully retracted.

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2014202328 30 Apr 2014 [0042] The inability to deadlock the latch assembly 20 from inside will now described with reference to Fig. 11. For the latch assembly 20 to be able to be deadlocked from inside, the internal key 72 must be able to drive the cam 48 clockwise with reference to Fig. 11 or anticlockwise with reference to Fig. 8. However, such key rotation is prevented by the anti-locking tab 98 on the inner drive plate 64 and an inwardly projecting lug 106 on the bolt drive member 46. As shown in Fig. 8, the inner drive plate 64 is driven by the inner key 72 and the bolt drive member 46 is rotationally fixed to the lever 70 by the protuberances 100. As a result, the latch assembly 20 cannot be deadlocked from the inside as the inner key 72 cannot be sufficiently rotated in order to do so.

[0043] The latch assembly 20 described above has two main advantages. Firstly, the latch assembly can only be deadlocked by using the outer key to operate the outside lock. This prevents a building occupant from activating deadlocking from inside a building or room, which can prevent or delay escape in an emergency if the correct key cannot be easily and quickly located and operated. This improves the safety of the building/room occupant. Deadlocking is still available from outside, allowing the building/room to be secured. Secondly, the incorporation of the deadlocking indicator into the detent, being the actual component that locks the inner side of the latch assembly, simplifies the construction and operation of the latch assembly, and reduces the number of components required. In addition, the indicator is advantageously not able to provide a false indication as the indicator panel cannot move independently of the detent.

[0044] Although the invention has been described with reference to a preferred embodiment, it will be appreciated by persons skilled in the art that the invention may be embodied in many other forms. For example, the detent can in addition or in the alternative have, for example, a green indicator panel visible when the latch assembly is not locked.

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Claims (6)

1. A latch assembly including: a casing;

a latch bolt mounted on the casing for movement relative thereto between an extended latching position and a retracted opening position;

an inner actuator operable from an inner side of the latch assembly to retract the latch bolt to the retracted opening position;

a detent having an active position, rendering the inner actuator inoperable, and an inactive position, in which the inner actuator is operable; and a visual condition indicator on, or forming part of, the detent which provides an indication on whether the detent is in the active position or the inactive position that is visible from an inner side of the latch assembly.

2. The latch assembly as claimed in claim 1, wherein the visual condition indicator is visible from the inner side of the latch assembly when the detent is in the active position and is not visible from the inner side of the latch assembly when the detent is in the inactive position.

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3. The latch assembly as claimed in claim 1, wherein the visual condition indicator is not visible from the inner side of the latch assembly when the detent is in the active position and is visible from the inner side of the latch assembly when the detent is in the inactive position.

4. The latch assembly as claimed in claim 1 or 2, wherein the casing has an opening in an inner side thereof and the visual condition indicator is visible through the opening when the detent is in the active position and is not visible through the opening when the detent is in the inactive position.

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5. The latch assembly as claimed in claim 1 or 3, wherein the casing preferably has an opening in an inner side thereof and the visual condition indicator is not visible through the opening when the detent is in the active position and is visible through the opening when the detent is in the inactive position.

6. The latch assembly as claimed in any one of claims 1 to 5, wherein the detent is biased towards the active position.

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7. The latch assembly as claimed in any one of claims 1 to 6, wherein the latch assembly further includes a cam adapted to move the detent from the active position to the inactive position.

8. The latch assembly as claimed in claim 7, wherein the detent abuts the cam.

9. The latch assembly as claimed in any one of claims 1 to 8, wherein the inner actuator includes an opening into which the detent can enter, the opening and the detent each having ramp surfaces that contact each other when the detent is the inactive position, such that pivotal movement of the inner actuator drives the detent out of the opening, and that do not contact each other when the detent is the active position, such that pivotal movement of the inner actuator is prevented.

10. The latch assembly as claimed in any one of claims 1 to 9, wherein the latch assembly further includes:

a first key operated lock operable from the inner side of the latch assembly and adapted to change the detent from the active position to the inactive position;

a first key control means adapted to prevent the first key operated lock from changing the locking means from the inactive condition to the active condition; and an outer key operable actuator operable from the outer side of the latch assembly and adapted to change the locking means from the active condition to the inactive condition, and retract the latch bolt to the retracted opening position, and also change the locking means from the inactive condition to the active condition.

Gainsborough Hardware Industries Limited Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON

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