AU2017272227B2 - A latch mechanism - Google Patents

Abstract

A latch mechanism for latching a slidable panel to a fixed member is disclosed. The latch mechanism including a housing mountable on one of the slidable panel and the fixed member; at least one latching member mounted in the housing, the at least one 5 latching member being movable between a first position for engaging with the other of the slidable panel and the fixed member, and a second disengaged position; and a reconfigurable operative mechanism which is selectively reconfigurable to move the at least one latching member between the first and second positions, wherein the reconfigurable operative mechanism includes first and second projectable portions at 10 opposite ends or sides of the housing which are selectively user operable to reconfigure the operative mechanism and move the at least one latching member, wherein the first and second projectable portions each include indicator portions, each of the first and second projectable portions being movable between an extended position projecting from the housing and a retracted position relative to the extended position, such that the 15 movement of the projectable portions between the extended and retracted positions results in the indicator portions being respectively uncovered and covered by the housing, such that when one of the first and second projectable portions projects out of the housing the extended position, the other of the first and second projectable portions is fully received in the housing in the retracted position. ?0 Figure 6A bL -7) Figure 60 Figure 6A Figure 6D

Description

bL

Figure 6A

-7)

Figure 60

Figure 6A

Figure 6D

A latch mechanism

Field of the invention

The present invention relates to latch mechanisms for releasably latching a slidable panel, such as a slidable door or window, to a fixed member, such as a frame.

Background of the invention

Australian patent no. 2003252202 discloses a latch mechanism for a slidable door or panel. The latch mechanism includes a housing having a pair of user-operable control knobs projecting at opposite ends of the housing, and a pair of latch tongues or hooks movable between an extended position in which the latch tongues extend from the housing and are engageable with a fixed member, such as a door frame, and a retracted position relative to the extended position in which the latch tongues are located in the housing. The latch tongues are caused to move between the extended and retracted positions due to the sliding movement of a pair of slidable members located within the housing, each control knob being integral with, or connected to, one of the slidable members. The slidable members include rack gears and are coupled by a central pinion gear. The arrangement is such that movement of one of the slidable members (or the control knob thereof) in a first direction causes movement of the other slidable member (and therefore, the other control knob) in a second, opposite, direction.

The abovedescribed latch mechanism suffers from certain disadvantages. For example, an unfamiliar user of the latch mechanism may be unaware which control knob must be actuated to move the latch tongues between the extended and retracted position, or even if a choice of the control knob is required (i.e., the unfamiliar user is unaware that each control knob performs the same operation). Additionally, there is no indication to the unfamiliar user, save for the position of the control knobs (of which the user is not familiar), whether the latch mechanism is latched or unlatched (i.e., whether the latch tongues are in the extended or retracted position). As such, the unfamiliar user will be required to visually inspect the latch tongues and/or attempt to move the slidable door or panel to determine the latching state of the latch mechanism.

It is an object of the present invention to provide a latch mechanism for latching a slidable panel to a fixed member that overcomes, or at least ameliorates, one or more of abovementioned disadvantages, or is at least a useful design choice over known latch mechanisms.

Reference to any prior art in the specification is not an acknowledgment or suggestion that this prior art forms part of the common general knowledge in any jurisdiction or that this prior art could reasonably be expected to be understood, regarded as relevant, and/or combined with other pieces of prior art by a skilled person in the art.

Summary of the invention

In accordance with an aspect of the present invention, there is provided a latch mechanism for latching a slidable door or window to a fixed door or window frame, the latch mechanism including:

a housing mountable on one of the slidable door or window and the fixed door or window frame;

at least one latching member mounted in the housing, the at least one latching member being movable between a first position for engaging with the other of the slidable door or window and the fixed door or window frame, and a second disengaged position; and

a reconfigurable operative mechanism which is selectively reconfigurable to move the at least one latching member between the first and second positions, wherein the reconfigurable operative mechanism comprises a slidable member having a longitudinal axis, wherein the slidable member is configured to slide longitudinally relative to the housing;

wherein the reconfigurable operative mechanism includes first and second projectable portions at opposite ends or sides of the housing which are selectively user operable to reconfigure the operative mechanism and move the at least one latching member,

wherein the projectable portions are disposed at opposite ends of the slidable member and at opposite ends of the housing, wherein the slidable member is arrangeable in the housing in either a first orientation or a second orientation, the second orientation being flipped 1800 about a transverse axis of the slidable member from the first orientation, wherein the first and second projectable portions each include indicator portions configured to provide an indication of a latching or unlatched state of the latch mechanism, each of the first and second projectable portions being movable between an extended position projecting from the housing and a retracted position relative to the extended position, such that the movement of the projectable portions between the extended and retracted positions results in the indicator portions being covered or uncovered by the housing, such that when one of the first and second projectable portions projects out of the housing in the extended position, the other of the first and second projectable portions is fully received in the housing in the retracted position, wherein, in the first orientation of the slidable member, the first projectable portion projects from the housing at a first end or side of the housing when in the extended position, and wherein the second projectable portion projects from a second end or side of the housing when in the extended position, and wherein, in the second orientation of the slidable member, the first projectable portion projects from the housing at the second end or side of the housing when in the ?0 extended position, and wherein the second projectable portion projects from the first end or side of the housing when in the extended position.

When uncovered, the indicator portion becomes visible to the user.

The first and second projectable portions may move in synchronicity such that when the first projectable portion is in the extended position, the second projectable portion is in the retracted position and vice versa.

The projectable portions may be in the form of push buttons with the indicator portions provided therein or thereon, e.g. in the form of a tab. Each indicator portion may be centrally disposed on its associated push button.

The projectable portions may be incorporated into or form an integral part of one or more slidable members which form part of the reconfigurable operative mechanism. In a preferred form of the invention, there is a single slidable member having a longitudinal axis with the slidable member sliding longitudinally relative to the housing. With the single slidable member, the projectable portions or push buttons are suitably disposed at opposite ends of the slidable member and at opposite ends of the housing.

The single slidable member may be arranged in the housing in a first orientation or a second orientation, the second orientation being offset 1800 about a transverse axis of the slidable member from the first orientation. As such, in the first orientation, the first projectable portion may project from the housing at a first end or side of the housing when in the extended position, and in the second orientation, the first projectable portion may project from the housing at a second end or side of the housing when in the extended position, the second end or side being opposite to the first end or side. Furthermore, in the first orientation, the second projectable portion may project from the second end or side of the housing when in the extended position, and in the second orientation, the second projectable portion may project from the first end or side of the housing when in the extended position. Advantageously therefore, a user of the latch mechanism may arrange a selected one of the indicator portions at either the first end or side of the housing or at the second opposite end or side of the housing, as the user desires.

3A

The indicator portions will be alternately visible and covered depending on the position of the single slidable member. For instance, when the position of the slidable member corresponds to the engaged position of the at least one latching member, the projecting indicator portion may indicate this latching state, for example by a red coloured indicator portion being exposed. On the other hand, when the position of the slidable member corresponds to the disengaged position of the at least one latching member, then the indicator portion which is visible and uncovered by projecting beyond the housing, may indicate an unlatched state and may be in the form of a green coloured indicator portion.

The single slidable member arrangement is only one possible arrangement for the reconfigurable operative mechanism. It may be possible to have two or more slidable members which act in concert with opposite projectable portions of the two or more slidable members defining the projectable portions. For example, where there are two slidable members, one projectable portion may be arranged on each slidable member with the two projectable portions arranged at opposite ends of the housing. The reconfigurable operative mechanism may enable the slidable members to move in opposite directions. See for example US Patent 7,228,719, the disclosure of which is incorporated herein by reference.

Preferably the arrangement of the indicator portions is such that when one of the ?0 projectable portions extends out of the housing, the associated indicator portion is exposed and thereby visible. However, alternative arrangements are possible where there are viewing windows provided in the housing and the indicator portion is visible, depending upon the position of the associated projectable portion.

The indicator portion may simply comprise painted portions on the projectable portions/push buttons. Alternatively, the indicator portion may be formed by over moulding of a coloured plastic component into the projectable portion/push button. The form of the push button may be a plastic moulded component provided at the end of a metal bar forming the slidable member. The push button may be over-moulded onto the metal slidable member.

The reconfigurable operative mechanism may be operable internally e.g. from an internal side of the slidable panel and this is suitably achieved by user manipulation of the projectable portions. The operative mechanism may also be operable externally, for example from outside of the slidable panel, for example, by an external actuator or lock, such as a key-operated lock. Any reference to "an internal side of the slidable panel" or similar and "an external side of the slidable panel" or similar respectively refers to a first space or environment, such as a room, and a second space or environment, such as a space outside of the room, the first and second spaces being separated by the slidable panel.

A deadlock may also be provided to preclude internal operation by the projectable portions or push buttons, unless the deadlock is de-activated, suitably by a key. Thus, the reconfigurable operative mechanism is selectively reconfigurable. This may take account of the operation of the deadlock as to whether the operative mechanism is reconfigurable at any particular time.

The at least one latching member may be in the form of a latch tongue. Suitably, there are two latch tongues which rotate in synchronism in opposite rotational directions about respective rotational axes as is known in the art. In a preferred form of the invention, the latch mechanism is provided on the slidable panel and the latching member(s) is engageable with a striker plate, suitably provided on a door jamb.

As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and ?0 "comprised", are not intended to exclude further additives, components, integers or steps.

Further aspects of the present invention and further embodiments of the aspects described in the preceding paragraphs will become apparent from the following description, given by way of example and with reference to the accompanying drawings.

Brief description of the drawings

Figure 1A is a perspective view of a handle for a slidable panel including a latch mechanism according to an embodiment of the invention;

Figure 1B is similar to Figure 1A;

Figure 2A is a perspective view of the latch mechanism of Figure 1 in a first orientation;

Figure 2B is similar to Figure 2A;

Figure 3A is a perspective view of the latch mechanism of Figure 2 in a second orientation;

Figure 3B is similar to Figure 3A;

Figure 4 is an exploded view of various components of the latch mechanism of Figure 1;

Figure 5 is another perspective view of the latch mechanism of Figure 1;

Figures 6A to 6H are top-down views of the latch mechanism of Figure 1 in various operating states;

Figure 7A is a perspective view of a component of the latch mechanism of Figure 1;

Figure 7B is a top-down view of a section of the latch mechanism of Figure 1;

Figure 8A is a close-up perspective view of a section of the latch mechanism of Figure 2A;

Figure 8B is similar to Figure 8A;

Figure 9A is a perspective view of an alternative handle housing including a latch mechanism according to an embodiment of the invention;

Figure 9B is similar to Figure 9A;

Figure 10 is a top-down sectional view of the handle housing of Figure 9;

Figure 11A is a close-up top-down view of a section of the handle housing of Figure 10; and

Figure 11B is similar to Figure 11A.

Detailed description of the embodiments

Referring to Figures 1A and 1B, there is a shown a latch mechanism 10 according to an embodiment of the invention. The latch mechanism 10 is disposed within a generally rectangular handle housing 12. The handle housing 12 may be mounted upon one of a slidable panel or a fixed member (not shown) for releasably latching the slidable panel and fixed member. As is typical in the art, the slidable panel may be a slidable door or window, and the fixed member may be a fixed door or window frame. Although the handle housing 12 of Figures 1A and 1B is generally rectangular, a person skilled in the art will appreciate that the latch mechanism 10 of the present invention may be disposed within a variety of differently shaped handle housings (see Figures 9A and 9B for example), and that the illustrated housing 12 is merely exemplary. Furthermore, a person skilled in the art will appreciate that the handle housing 12 may be integral with (as opposed to being mounted upon) one of the slidable panel and fixed member.

The latch mechanism 10 includes a pair of similar latching members in the form of hook-like latch tongues 14 (Figure 1B). The latch tongues 14 are mounted within the housing 12 and are rotatably movable between a first position (Figure 1B) for engaging, for example a keeper component (not shown), on the other of the slidable panel or fixed member (to which the housing 12 is not mounted upon), and a second, disengaged, ?0 position (Figure 1A). In the first position, the latch mechanism 10 releasably latches the slidable panel and the fixed member, whereas in the second position, the slidable panel and the fixed member are unlatched or disengaged.

The latch mechanism 10 includes a reconfigurable operative mechanism including an elongate slidable member 16 (Figure 4). As is described in detail later, the slidable member 16 is reconfigurable by sliding to move the latch tongues 14 between the first and second positions. Referring to Figure 4, the slidable member 16 includes, at a first end 18, a first projectable portion in the form of a first push button 22. The slidable member 16 also includes, at a second opposite end 20, a second projectable portion in the form of a second push button 24. The first and second push buttons 22, 24 are selectively user operable, by pushing or pressing, to reconfigure the slidable member 16 and move the latch tongues 14 between the first and second positions.

As is illustrated in Figures 1A and 1B, the first and second push buttons 22, 24 are movable between an extended position projecting from an end or side of the housing 12, and a retracted position relative to the extended position. Particularly, when the first push button 22 is in the extended position projecting out of the housing 12, the second push button 24 is fully received in the housing 12 in the retracted position (Figure 1A), and vice versa. The first and second push buttons 22, 24 move in synchronicity between the extended and retracted positions.

Advantageously, each of the first and second push buttons 22, 24 include respective first and second indicator portions 26, 28 that are respectively uncovered or covered by the housing 12 as the push buttons 22, 24 are moved between the extended and retracted positions. When uncovered, the first or second indicator portion 26, 28 becomes visible to the user and indicates a latching state of the latch mechanism 10. In a preferred form of the invention, the first indicator portion 26 is coloured green and the second indicator portion 28 is coloured red. Accordingly, when the position of the slidable member 16 corresponds to the first or engaged position of the latch tongues 14 (Figure 1B), the projecting push button 24 indicates this latching state by the red indicator portion 28 being visible to the user. On the other hand, when the position of the slidable member 16 corresponds to the second or disengaged position of the latch tongues 14 (Figure 1A), the projecting push button 22 indicates this unlatched state by ?0 the green indicator portion 26 being visible to the user. When the green indicator portion 26 is uncovered and visible, the red indicator portion 28 is covered by the housing 12 and is not visible, and vice versa.

The various components of the latch mechanism 10 will now be described in greater detail.

Referring initially to Figure 4, the slidable member 16 is elongate and generally rectangular in overall form and includes approximately T-shaped opposite first and second outer ends 18, 20 respectively aligned along a longitudinal axis. Each T-shaped end 18, 20 includes a generally rounded-rectangular aperture 30 centrally disposed in the transverse portion of the "T" of each end 18, 20. Releasably mounted at each end 18, 20 are the respective first and second push buttons 22, 24. The push buttons 22, 24 are rectangular prisms having a closed top end 32 adapted to be pushed/pressed by a finger, and an opposite open bottom end 34 adapted to be mounted over the T-shaped ends 18, 20 of the slidable member 16. The push buttons 22, 24 also include a generally rounded-rectangular aperture or slot 36 on a front face 38, the apertures 36 being similar in overall dimension to the centrally disposed aperture 30 of T-shaped ends 18, 20. The push buttons 22, 24 are mounted upon the T-shaped ends 18, 20 and respectively secured thereto by the first, green, and second, red, indicator portions 26, 28, the indicator portions 26, 28 being dimensioned to slidably fit into the aligned apertures 36, 30 of the push buttons 22, 24 and the T-shaped ends 18, 20 of the slidable member 16. In other words, the push buttons 22, 24 are secured to the outer ends 18, 20 of the slidable member 16 by the respective indicator portions 26, 28 being interference fit into the aligned apertures 36, 30. In this manner, the indicator portions are visible (when uncovered by the housing 12) on the front face 38 of each push button 22,24.

The slidable member 16 also includes a first, outer, pair of generally oblong slots 40 arranged along the longitudinal axis of the slidable member 16, and a second, inner, pair of generally oblong slots 42 disposed inwardly of the outer slots 40 (i.e., toward the longitudinal and transverse centre of the slidable member 16). The second oblong slots 42 are smaller in overall dimension as compared to the first oblong slots 40, and each second slot 42 is arranged offset from the longitudinal axis toward an opposite ?0 longitudinal side of the slidable member 16. Specifically, as is illustrated in Figure 4, an upper one of the second slots 42 is arranged offset from the longitudinal axis toward a first longitudinal side 44 of the slidable member 16, and a lower one of the second slots is arranged offset from the longitudinal axis toward a second, opposite, longitudinal side 46 of the slidable member 16. Each of the first and second slots 40, 42 define a slide path of the slidable member 16, as is discussed below.

The slidable member 16 is mounted upon a generally rectangular mounting plate 50. The mounting plate 50 includes a pair of cylindrical bosses 52 aligned along a longitudinal axis of the mounting plate 50 and arranged adjacent opposite outer longitudinal ends of the mounting plate 50. The cylindrical bosses 52 are dimensioned to be slidably located in the first, outer, pair of slots 40 of the slidable member 16. In this manner, the slidable member 16 is slidably mounted upon the mounting plate 50 about the cylindrical bosses 52. As is shown in Figures 2A and 2B, the slidable member 16 is slidable between a position corresponding to the first, engaging, position of the latch members 14 (Figure 2B) and a position corresponding to the second, disengaged, position of the latch members 14 (Figure 2A). In the engaging position, the cylindrical bosses 52 are located at a first longitudinal end of the slots 40, and in the disengaged position, the cylindrical bosses 52 are located at a second opposite longitudinal end of the slots 40. As is described above, the slidable member 16 is slidable between the engaging position and the disengaged position by a pushing/pressing force on either of the first and second push buttons 22, 24. In this manner, the slidable member 16 is operable internally, i.e. from an internal side of the slidable panel (not shown) by user manipulation of the push buttons 22, 24. The slidable member 16 is also operable externally, i.e. from outside of the slidable panel by a key-operated lock, discussed later.

The mounting plate 50 also includes a ball detent 220 at a lower end thereof that projects laterally from a side of the mounting plate 50 closest to the first longitudinal side 44 of the slidable member 16 (Figure 4). The ball detent 220 is adapted to engage either an upper side 222a or lower side 222b of a generally semi-circular projection 222 projecting from the first longitudinal side 44 nearest a lower end of the slidable member 16. The ball detent 220 and semi-circular projection 222 are dimensioned and configured such that a minimum positive pushing/pressing force on the push buttons 22, 24 is required to move the projection 222 about or around the ball detent 220, thereby ?0 allowing the slidable member 16 to move between engaging and disengaged positions. In essence, the ball detent 220 prevents accidental or unintended movement of the latch tongues 14 between the engaging and disengaged positions until a positive pushing/pressing force is applied to the push buttons 22, 24.

Mounted upon the cylindrical bosses 52, between the slidable member 16 and mounting plate 50, are the pair of hook-like latch tongues 14. The latch tongues 14 include a generally circular portion 60 and an integral radially extending generally L shaped hook portion 62. The circular portion 60 includes a slot 64 having a central circular aperture 66 and radially extending generally L-shaped ends 68 extending in opposite directions from a common axis from the central aperture 66. The central aperture 66 is dimensioned to be mounted upon the cylindrical bosses 52 of the mounting plate 50, and one of the L-shaped ends 68 is dimensioned to receive a generally rectangular tab 70 located within, and extending through, the first pair of generally oblong slots 40 of the slidable member 16. As can be seen in Figure 4, a lower one of the first slots 40 of the slidable member 16 includes the rectangular tab 70 on a side of the lower slot 40 closest the second longitudinal side 46 of the slidable member 16, and an upper one of the first slots 40 includes the rectangular tab 70 on a side of the upper slot 40 closest the first, opposite, longitudinal side 44 of the slidable member 16. As the slidable member 16 is caused to slide upon the mounting plate 50 by the pushing/pressing force on either of the first and second push buttons 22, 24, the latch tongues 14 are caused to rotate in synchronism in opposite rotational directions about rotational axes defined by the central apertures 66 and the cylindrical bosses 52 due to the rectangular tabs 70 of the slidable member 16 being located in the L-shaped ends 68 of the latch tongues 14.

The latch mechanism 10 also includes a locking element in the form of a generally L-shaped member 80 (Figure 4), the L-shaped locking member 80 being configured to releasably lock the slidable member 16 in either of the positions corresponding to the engaging and disengaged positions of the latch tongues 14. The locking member 80, similar to the latch tongues 14, is disposed between the slidable member 16 and the mounting plate 50. The locking member 80 includes at a first, upper, end 82 a circular aperture 84 which receives a first generally circular pin 86 about which the locking member 80 is pivotally mounted to the mounting plate 50. The ?0 first, upper, end 82 of the locking member 80 is opposite to a second, lower, end 94 adjacent to the "bend" in the L-shaped member.

The locking member 80 is secured between the slidable member 16 and the mounting plate 50 by the circular pin 86 being received through the upper one of the second, inner, pair of generally oblong slots 42 of the slidable member 16, the circular aperture 84 of the locking member 80, and an upper circular aperture 88 located on the mounting plate 50 disposed below an upper one of the cylindrical bosses 52. The circular pin 86 includes a first, outer, portion 90 having a first diameter corresponding to a diameter of the circular aperture 88 of the mounting plate 50, and a second, inner, portion 92 having a second diameter corresponding to a width of the oblong slot 42, the second diameter being greater than the first diameter.

The locking member 80 also includes at the second, lower, end 94 on the "straight" side of the member 80 a generally rectangular protruding tab 96 that engages, in the manner described below, a generally rectangular detent 98 protruding from the first longitudinal side 44 of the slidable member 16 to releasably lock the slidable member in either of the aforementioned positions corresponding to the engaging and disengaged positions of the latch tongues 14.

The locking member 80 is biased in a direction toward the longitudinal axis of the slidable member 16 by an open torsion spring 100. As a result, the protruding tab 96 of the locking member 80 is biased to engage the first longitudinal side 44 of the slidable member 16 and the detent 98. The torsion spring 100 has a central curved section 102 and a pair of diverging arms 104 extending therefrom. The central curved section 102 is located about the circular pin 86, and one of the pair of diverging arms 104 is attached within another circular aperture 106 located on the mounting plate 50 generally adjacent to the circular aperture 88, and the other one of the pair of diverging arms 104 is attached within another circular aperture 108 located on the locking member 80 below the circular aperture 84. The circular apertures 88, 106 of the mounting plate 50 are aligned along a transverse axis, and the circular apertures 84, 108 of the locking member 80 are aligned along a longitudinal axis. When the protruding tab 96 engages the detent 98, the slidable member 16 is prevented from sliding along the mounting ?0 plate 50 (as will be described below).

The latch mechanism 10 also includes a second generally circular pin 110 received through the lower one of the second, inner, pair of generally oblong slots 42 of the slidable member 16 and a lower circular aperture 112 located on the mounting plate 50. The circular aperture 112 is disposed above a lower one of the cylindrical bosses 52 and aligned with aperture 88 along a longitudinal axis. Together, the pins 86 and 110 secure the slidable member 16, locking member 80, and latch tongues 14 to the mounting plate 50 so as to define a latch module 120 of the latch mechanism 10. Advantageously, the latch module 120 is mountable to a generally rectangular base plate 130 of the latch mechanism 110 (Figure 4) in a first orientation (Figures 2A and 2B) or a second orientation (Figures 3A and 3B), the second orientation being offset 1800 (or flipped) about a transverse axis of the slidable member 16 from the first orientation. As such, a user of the latch mechanism 10 has a choice as to which push button 22, 24 having respective green and red indicators 26, 28 is located at an upper end 13 of the housing 12 and a lower end 15 of the housing 12 (Figure 1). For example, if the user desires the red "latched" indicator 28 to be displayed at the upper end 13 of the housing 12, then the user would mount the latch module 120 to the base plate 130 in the first orientation (Figures 2A and 2B) such that the second push button 24 extends out of the upper end 13 of the housing 12 in extended position corresponding to the first (or engaging) position of the latch tongues 14. On the other hand, if the user desires the red "latched" indicator 28 to be displayed at the lower end 15 of the housing 12, then the user would mount the latch module 120 to the base plate 130 in the second orientation (Figures 3A and 3B) such that the second push button 28 extends out of the lower end 15 of the housing in the extended position corresponding to the first (or engaging) position of the latch tongues 14 (also see Figure 1B).

Referring back now to Figure 4, it can be seen that the generally rectangular base plate 130 includes a pair of protruding generally U-shaped surfaces 132 disposed slightly inwardly of respective upper and lower longitudinal ends 134, 136 of the base plate 130. The U-shaped surfaces 132 include opposite protruding arms 140 located adjacent respective opposite longitudinal sides 142, 144 of the base plate 130. The protruding arms 140 define a space therebetween through which a portion of the slidable member 16 near the T-shaped outer ends 18, 20 is slidable.

?0 The base plate 130 also includes a central circular aperture 150 located at the longitudinal and transverse centre of the base plate 130. The central aperture 150 is dimensioned to receive a cam member 160 that is adapted to drive the slidable member 16 between the engaging and disengaged positions of the latch tongues 14. Referring to Figure 7A, the cam member 160 includes a lower cylindrical portion 162 dimensioned to be received through the central aperture 150 of the base plate 130, a double-pinned upper portion 164 appearing generally "figure 8" when viewed top-down, and a cross like central portion 166 disposed between the lower portion 162 and the upper portion 164. The cross-like central portion 166 is rotatably seated on the base plate 130 about the central aperture 150. The double-pinned upper portion 164 includes a first, central, cylindrical pin 168 disposed along a central vertical axis, and a second, outer, cylindrical pin 170 integral with the first pin 168. The second, outer, pin 170 includes a transverse slot 180 configured to interface with the L-shaped locking member 80 in the manner shown in Figure 7B (and described later) to move the locking member 80 against its bias (provided by torsion spring 100) and to thereby disengage the protruding tab 96 of the locking member 80 from the detent 98 of the slidable member 16 to allow the slidable member 16 to slide with respect to the mounting plate 50 (as is discussed in greater detail below).

The lower cylindrical portion 162 of the cam member 160 includes a generally rectangular axial slot (not shown) configured to receive a generally rectangular tailbar 190 extending from a key-operated lock cylinder 192 (Figure 5). As is known to those skilled in the art, rotation of a key (not shown) of the key-operated lock cylinder 192 causes likewise rotation of the tailbar 190 and therefore likewise rotation of the cam member 160 to which the tailbar is connected. The cam member 160 also interfaces with the slidable member 16 in the manner described below. Accordingly, rotation of the cam member 160 causes the slidable member 16 to slide with respect to the mounting plate 50, and therefore, the slidable member 16 is reconfigurable externally, i.e, from an external side of the slidable panel.

When the latch module 120 is mounted to the base plate 130, an upper portion 194 of the second, outer, pin 170 of the cam member 160 is received through a central circular aperture 146 of the mounting plate 50 and is located in a central aperture 200 (Figure 4) of the slidable member 16. The upper portion 194 is located above the ?0 transverse slot 180. The central aperture 200 of the slidable member 16 includes a first generally curved side 202 disposed adjacent to the second longitudinal side 46 of the slidable member 16, and a second generally straight side 204 having a central semi circular recess 206 disposed adjacent to the first longitudinal side 44 of the slidable member 16. In the manner illustrated in Figure 6 below, the upper portion 194 of the cam member 160 may sit within the semi-circular recess 206 and drivingly engage the slidable member 16 to move the slidable member 16. Advantageously, the upper portion 194 of the cam member 160 has a similar outer dimension to the semi-circular recess 206.

As is described above, the slidable member 16 is reconfigurable to move the latch tongues 14 between the engaging and disengaged positions by being operated internally, i.e. from the internal side of the slidable panel by pushing/pressing the push buttons 22, 24, or by being operated externally, i.e., from an external side of the slidable panel by operating the key-operated lock cylinder 192 to rotate the cam member 160.

The latch mechanism 10 includes an internal key-operated lock cylinder (not shown), similar to the external key-operated lock cylinder 192. The internal key operated lock cylinder is selectively configurable by a key to reconfigure the locking member 80 in either a first, locked, configuration or a second, unlocked, configuration. In the first, locked, configuration, the protruding tab 96 of the locking member 80 is maintained in an engaging position with the detent 98 of the slidable member 16 such that the slidable member 16 is prevented from sliding relative to the mounting plate 50. In the second, unlocked, configuration, the locking member 80 is held against its bias such that the protruding tab 96 is disengaged from the detent 98 thereby allowing the slidable member 16 to slide relative to the mounting plate 50 by pushing/pressing the push buttons 22, 24.

Referring back to Figure 4, the latch mechanism 10 also includes a locking plate 230 configured to interface with a cam member of the internal key operated lock cylinder (not shown). The locking plate 230 includes a generally rectangular base portion 232 having a pair of outwardly projecting "wings" 234 located at a first end, and a pair of laterally projecting tabs 236 located a second, opposite, end. A generally rounded-rectangular cut-out 238 is centrally located between the pair of wings 234 and ?0 defines, along an inner edge, a camming surface 237 configured to interface with a cam member (not shown) of the internal key-operated lock cylinder (not shown). As is typical in the art, the internal key-operated lock cylinder drivingly rotates the cam member upon rotation of the key. As the cam member is rotated, it engages the camming surface 237 of the locking plate 230 to slidingly move the locking plate 230, relative to mounting plate 50, adjacent the second longitudinal side 46 of the slidable member 16. This motion is illustrated in Figures 8A and 8B.

In Figure 8A, the locking plate 230 is in a position corresponding to the first, locked, configuration of the locking member 80. In this position, the protruding tab 96 of the locking member 80 engages the first longitudinal side 44 of the slidable member 16 and the detent 98, thereby preventing the slidable member 16 from sliding relative to the mounting plate 50. Upon operation of the internal key-operated lock cylinder, the locking plate 230 is caused to slide relative to the mounting plate 50, due to rotation of the cam member, to the position illustrated in Figure 8B. In this position, the base portion 232 of the locking plate 230 engages the end 94 of the locking member 80 and moves the locking member 80 against its bias such that the protruding tab 96 is maintained in a position disengaged from the detent 98, thereby allowing the slidable member 16 to move relative to the mounting plate 50 by pushing/pressing the push buttons 22, 24. The position of the locking plate 230 in Figure 8B corresponds to the second, unlocked, configuration of the locking member 80. Thus, when the internal lock cylinder is in the second, unlocked, configuration, the slidable member 16 is movable relative to the mounting plate 50 through the use of the push buttons 22, 24 at the will of the user.

External operation of the latch mechanism 10, via the external key-operated lock cylinder 192, will now be described with reference to Figures 6A to 6H. Referring initially to Figures 6A, the latch tongues 14 are shown in the engaging position and the push button 24 with the red indicator portion 28 is shown in the extended position (projecting from the housing 12, not shown). The push button 22 with the green indicator portion 26 is shown in the retracted position (fully received in the housing 12, not shown). Additionally, the protruding tab 96 of the locking member 80 is shown engaging a first side of the detent 98 of the slidable member 16. Accordingly, the slidable member 16 is releasably locked in the position corresponding to the engaging position of the latch ?0 tongues 14.

As a user operates the key-operated lock cylinder 192 with a key, the cam member 160 is caused to rotate in a clockwise direction (Figure 6B) until the transverse slot 180 of the cam member 160 engages an inner side of the L-shaped locking member 80 and moves the locking member 80 against its bias to disengage the tab 96 from the detent 98 (Figure 6C). In this position, the slidable member 16 is unlocked and slidable with respect to the mounting plate 50. As the user continues to rotate the key, the upper portion 194 of the cam member 160 becomes located in the semi-circular recess 206 of the slidable member 16 (Figure 6D) and begins to drivingly engage the slidable member 16 to move the slidable member. As the slidable member 16 moves with respect to the mounting plate 50 (i.e. to the right as shown in Figure 6E), the latch tongues 14 are caused to rotate from their engaging position to their disengaged position due to the rectangular tabs 70 of the slidable member 16 being located in the L shaped ends 68 of the slot 64 of each latch tongue 14. Continued clockwise rotation of the key causes likewise rotation of the cam member 160 (Figures 6F and 6G) until the latch tongues 14 are in their disengaged position (Figure 6H) and the push button 22 with the green indicator portion 26 is shown in the extended position (projecting from the housing 12, not shown). In this position also, the push button 24 with the red indicator portion 28 is in the retracted position (fully received in the housing 12, not shown). Additionally, as progressively seen in Figures 6E to 6H, as the cam member 160 rotates out of the semi-circular recess 206 of the slidable member, the locking member 80 returns to its locking position due to the bias of spring 100 until the tab 96 is fully engaged with a second, opposite, side of the detent 98 (Figure 6H).

The latch mechanism 10 may be mounted to the slidable panel via a pair of mounting screws 210 (Figures 4 and 5) received through central apertures 212 of the cylindrical bosses 52 and apertures 214 of the base plate 130.

Figures 9A and 9B illustrate a generally D-shaped handle housing 12' (when viewed from a rear-side) including a latch mechanism 10' according to a second embodiment of the invention. In the second embodiment, like numerals represent like parts. Parts which have been modified or adapted for the second embodiment are indicated by prime symbol (').

Similar to the first embodiment, the D-shaped handle housing 12' may be ?0 mounted upon one of a slidable panel or a fixed member (not shown) for releasably latching the slidable panel and fixed member. In Figure 9B, the latch tongues 14 are shown in the first, engaging, position for engaging the other of the slidable panel or fixed member. In Figure 9A, the latch tongues 14 are shown in the second, disengaged position.

The latch mechanism 10' is similar to the latch mechanism 10 of the first embodiment (Figures 1 to 8), except that the locking plate 230' (Figure 10) forms part of the handle housing 12'. Figure 10 illustrates a sectional view of the D-shaped handle housing 12' with the latch mechanism 10' removed for clarity. Received through a central aperture of the handle housing 12' is an internal key-operated lock cylinder 242 (the "internal" key-operated lock cylinder 242 being selectively reconfigurable from an internal side of the slidable panel by a key). As is typical in the art, the lock cylinder 242 drivingly rotates an elongate cam member 244 upon rotation of the key. This motion is illustrated in Figures 11A and 11B. As the cam member 244 is rotated in an anti clockwise direction, it engages a camming surface 237' of a generally rounded rectangular cut-out 238' of the locking plate 230' (Figure 11A). Continued anti-clockwise rotation of the cam member 244 causes the locking plate 230' to slide in a longitudinal direction along the handle housing 12' (Figure 11B) such that the locking plate 230' engages the locking member 80 of the latch mechanism 10' (not shown). Similar to the first embodiment of the invention, when the locking plate 230' engages the locking member 80, the locking member 80 is moved against its bias such that its protruding tab 96 is maintained in a position disengaged from the detent 98 of the slidable member 16, thereby allowing the slidable member 16 to move relative to the mounting plate 50 by pushing/pressing the push buttons 22, 24.

The position of the locking plate 230' in Figure 11B corresponds to the second, unlocked, configuration of the locking member 80, whereas the position of the locking plate 230' in Figure 11A corresponds to the first, locked, configuration of the locking member 80. The direction of sliding of the locking plate 230 and 230' depends upon the orientation of the latch module 120 on the base plate 130.

The latch module 10' of the second embodiment of the invention may also be operated externally (i.e., from an external side of the slidable panel) by an external key ?0 operated lock cylinder (not shown) similar to the lock cylinder 192 of the first embodiment of the invention.

The latch mechanisms 10 and 10' of the present invention offer certain advantages as compared to prior latch mechanisms. Firstly, the latch mechanisms 10 and 10' are relatively easy to use as only one projectable push button 22 or 24 is shown to a user depending upon the latching state of the latch mechanism (the other projectable push button being fully received in the housing). Additionally, the latch mechanisms 10 and 10' provide a user choice of the particular indicator portion 26 or 28 displayed at the upper or lower ends 13, 15 of the housing 12 and 12' as the latch module 120 of the latch mechanisms 10 and 10' may be oriented in two different orientations as described above.

It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Claims (12)

1. A latch mechanism for latching a slidable door or window to a fixed door or window frame, the latch mechanism including:

a housing mountable on one of the slidable door or window and the fixed door or window frame;

at least one latching member mounted in the housing, the at least one latching member being movable between a first position for engaging with the other of the slidable door or window and the fixed door or window frame, and a second disengaged position; and

a reconfigurable operative mechanism which is selectively reconfigurable to move the at least one latching member between the first and second positions, wherein the reconfigurable operative mechanism comprises a slidable member having a longitudinal axis, wherein the slidable member is configured to slide longitudinally relative to the housing;

wherein the reconfigurable operative mechanism includes first and second projectable portions at opposite ends or sides of the housing which are selectively user operable to reconfigure the operative mechanism and move the at least one latching member,

wherein the projectable portions are disposed at opposite ends of the slidable member and at opposite ends of the housing, wherein the slidable member is arrangeable in the housing in either a first orientation or a second orientation, the second orientation being flipped 1800 about a transverse axis of the slidable member from the first orientation,

wherein the first and second projectable portions each include indicator portions configured to provide an indication of a latching or unlatched state of the latch mechanism, each of the first and second projectable portions being movable between an extended position projecting from the housing and a retracted position relative to the extended position, such that the movement of the projectable portions between the extended and retracted positions results in the indicator portions being respectively uncovered and covered by the housing, such that when one of the first and second projectable portions projects out of the housing in the extended position, the other of the first and second projectable portions is fully received in the housing in the retracted position, wherein, in the first orientation of the slidable member, the first projectable portion projects from the housing at a first end or side of the housing when in the extended position, and wherein the second projectable portion projects from a second end or side of the housing when in the extended position, and wherein, in the second orientation of the slidable member, the first projectable portion projects from the housing at the second end or side of the housing when in the extended position, and wherein the second projectable portion projects from the first end or side of the housing when in the extended position.

2. The latch mechanism of claim 1, wherein the first and second projectable portions move in synchronicity such that when the first projectable portion is in the extended position, the second projectable portion is in the retracted position and vice versa.

3. The latch mechanism of claim 1 or 2, wherein the projectable portions are in the form of push buttons with the indicator portions provided therein or thereon.

4. The latch mechanism of any one of claims 1 to 3, wherein the projectable portions are incorporated into or form an integral part of the slidable member.

5. The latch mechanism of any one of claims 1 to 4, wherein, when the position of the slidable member corresponds to the engaged position of the at least one latching member, one of the first and second projectable portions is configured to project from the housing and indicate the latching state.

6. The latch mechanism of claim 5, wherein the latching state is indicated by a red coloured indicator portion on said one projectable portion being visible to the user.

7. The latch mechanism of claim 5 or 6, wherein, when the position of the slidable member corresponds to the disengaged position of the at least one latching member, the other of the first and second projectable portions is configured to project from the housing and indicate the unlatched state.

8. The latch mechanism of claim 7, wherein the unlatched state is indicated by a green coloured indicator portion on said other projectable portion being visible to the user.

9. The latch mechanism of any one of claims 1 to 8, wherein the reconfigurable operable mechanism is selectively operable from a first, internal, side of the slidable door or window by user manipulation of the projectable portions.

10. The latch mechanism of any one of claims 1 to 9, wherein the reconfigurable operable mechanism is selectively operable from a second, external, side of the slidable door or window by a key-operated lock.

11. The latch mechanism of claim 9 or 10, further including a deadlock configured to preclude operation of the projectable portions from the first, internal, side of the slidable door or window unless the deadlock is deactivated.

12. The latch mechanism of any one of claims 1 to 11, wherein the at least one latching member comprises two latch tongues, and wherein the two latch tongues rotate in synchronism in opposite rotational directions about respective rotational axes.