NZ757275A - Push/pull door latch mechanism and assembly - Google Patents

Abstract

A push/pull action user-operable actuator for a door latch mechanism mounted in a hinged or swinging door has a handle member pivotally supported for movement between a resting position and an operative position, and a lever arm coupled to the handle member and extending into the door structure for operative engagement with the door latch. Pivotal movement about a vertical axis of the handle member effects swinging motion of the lever arm for actuation of the door latch, in use. The push/pull action actuators are particularly useful in conjunction with a magnetic latch mechanism. operative engagement with the door latch. Pivotal movement about a vertical axis of the handle member effects swinging motion of the lever arm for actuation of the door latch, in use. The push/pull action actuators are particularly useful in conjunction with a magnetic latch mechanism.

Description

– 1 – Push/Pull Door Latch Mechanism and Assembly Field of the invention The present invention relates to door latches which are operable by pushing or pulling on a user actuator in order to withdraw the latch head to open the door. Push/pull actuator mechanisms of the present invention may be used with magnetically operated door latches.

Background A door latch assembly conventionally includes a spring-biased latch head that projects from the edge of a hinge-mounted door which is arranged to engage a strike plate in a corresponding door frame. The latch head is typically disengaged (retracted) by means of the user turning or twisting a door knob or handle to actuate the latch mechanism and manually retract the latch head, allowing the door to open. A characteristic of spring-biased moving latches is that the latch head is always resiliently biased to its extended position whether the door is open or closed.

In some applications it may be desirable for a door to be opened by pushing or pulling on a handle, rather than by turning or twisting. For example, push/pull door latches have been found particularly suitable for use on doors to hospital rooms and the like, wherein the door typically opens into the room. A hospital door provided with a push/pull type latch may be opened from the outside by applying pressure to the push side of the latch, and opened from the inside by pulling on the pull side of the latch. A push/pull operated latch allows for a hospital technician to enter a patient's room while carrying an armload of medical equipment by merely applying pressure to the push side of the latch, thereby unlatching the door and pushing it open. Conversely, a patient who may have limited use of his or her arms because of the presence of a cast or the like, can unlatch a door and open it from the inside by pulling on the inside handle, an effort requiring a minimum of dexterity.

In a magnetically operated door latch, the latch head remains retracted while the door is open and is drawn out into its extended configuration by magnetic forces when the latch head aligns with the strike plate aperture in the door frame. This operating principle – 2 – avoids certain difficulties that may be associated with an ordinary spring-biased latch, and also has other benefits, such as:  improved safety and aesthetics since the latch bolt remains retracted while the door is open and the strike plate does not require a protruding lip;  relatively quiet operation since the latch head is not required to impact the strike plate;  the door latch may be equally used on doors that open in either direction, or on doors that swing in both directions.

Notwithstanding the potential benefits of magnetically operated door latches and, in given circumstances, push/pull latch actuators, there are challenges involved in integrating them together in a manner that enables the benefits to be realised while also including a full range of features, such as operation in both a 'passage mode' and a 'privacy mode'.

Moreover, push/pull latch actuators more generally may provide user benefits that have not heretofore been fully realised and it would be desirable to provide door latch actuators of this type that may be more broadly implemented.

Summary of the invention In accordance with the present invention there is provided a push/pull action user- operable actuator for a door latch mechanism mounted within the structure of a hinged or pivoting door, comprising: a mounting member adapted for mounting on a door in relation to the door latch; a handle member pivotally supported by the mounting member for movement between a resting position and an operative position; a lever arm coupled to the handle member and extending into the door structure for operative engagement with the door latch, wherein pivotal movement of the handle member from the resting position to the operative position effects swinging motion of the lever arm for actuation of the door latch, in use.

In embodiments described herein the handle member is pivotally supported by the mounting member for pivotal movement about a vertical axis. – 3 – The handle member may include a handle pull portion or a handle push portion or both a handle pull portion and a handle push portion, wherein the handle member is user- operable for movement between the resting position and the operative position by pulling and/or pushing on the handle member as appropriate relative to the face of the door.

The push/pull door latch actuator preferably includes a spring arranged to apply a bias force to urge the handle member into the resting position in the absence of user action.

In accordance with the present invention there is provided a latch mechanism for a hinged or pivoting door, comprising: a housing adapted for mounting in or on a door; a latch slider supported by the housing for reciprocating movement between an extended position and a retracted position, the latch slider including a latch head having a magnetic component; a biasing means acting on the latch member to apply a bias force to the latch member toward the retracted position; wherein the latch slider is operatively drawn to its extended position by magnetic force when the latch head in use aligns with a magnetically susceptible strike member mounted on a corresponding door fixture; and wherein the latch slider includes an actuator engagement member adapted to engage with a lever arm of a push/pull user-operable actuator to in use effect retraction of the latch slider in opposition to said magnetic force.

The latch mechanism may include a privacy mode selection mechanism having a privacy engagement member moveable between a first position and a second position, wherein the privacy engagement member when in the second position engages with the latch slider to prevent retraction of the latch slider. The privacy mode selection mechanism may include a user operable privacy pin coupled to the privacy engagement member to enable movement of the privacy engagement member between the first and second positions. In embodiments the privacy pin and privacy engagement member are moveable transverse to an axis of movement of the latch slider.

The biasing means may comprise a compression spring. Alternatively, the biasing means may comprise at least one magnet. – 4 – The present invention also provides a door latch assembly including a latch mechanism as defined above together with at least one push/pull door latch actuator as defined above.

A door latch assembly according to embodiments of the invention may include a door latch mechanism together with first and second push/pull door latch actuators operatively mounted to a door on opposite sides of the door latch mechanism wherein the first and second lever arms of the respective first and second actuators are vertically displaced from one another to permit independent swinging motion thereof in use.

The latch mechanism may further include a latch mode mechanism user selectable to configure the latch mechanism into one of: a passage mode in which the latch slider may be retracted through operation of either of said first and second push/pull door latch actuators; and a privacy mode in which the latch slider may be retracted through operation of the first actuator but not the second actuator.

The latch mode mechanism may include a mode selection member supported by the housing for indexable movement transverse to the latch slider movement, the mode selection member arranged to block retracting movement of the latch slider when the privacy mode is selected.

In accordance another aspect of the present invention there is provided a door latch assembly including a latch mechanism as herein disclosed together with at least one sliding tab door latch actuator comprising: a mounting member adapted for mounting on a door in relation to the latch mechanism; a handle member supported by the mounting member for sliding movement between a resting position and an operative position; an actuator arm coupled to the handle member and extending into the door structure for operative engagement with the latch mechanism, wherein sliding movement – 5 – of the handle member from the resting position to the operative position effects linear motion of the actuator arm for actuation of the latch mechanism, in use.

Further aspects, features and advantages of the present invention will be apparent to those of ordinary skill in the art from the accompanying description and drawings.

Brief description of the drawings In order that the invention may be more easily understood, the following detailed description is provided including description of several embodiments, presented by way of example only, and with reference to the accompanying drawings in which: Figure 1 is an exploded perspective view of components of a magnetic door latch according to an embodiment of the invention having pull-operated door handle actuators; Figure 2 is a central horizontal sectional view of the door latch of Figure 1 installed in a door with latch head retracted; Figure 3 is a central horizontal sectional view of the door latch of Figure 1 installed in a door with latch head engaged in a strike plate; Figure 4 is a central horizontal sectional view of the door latch of Figure 1 installed in a door showing operation by way of the inside handle; Figure 5 is a central horizontal sectional view of the door latch of Figure 1 installed in a door showing operation by way of the outside handle; Figure 6 is a central horizontal sectional view of the door latch of Figure 1 installed in a door showing engagement of a privacy mechanism; Figure 7 is an enlarged view from Figure 6 showing privacy engagement detail; Figure 8 is a central horizontal sectional view of the door latch of Figure 1 installed in a door, illustrating disengagement of the privacy mechanism; Figures 9A and 9B are central horizontal sectional views of the door latch of Figure 1 installed in doors of different thicknesses; Figures 10A and 10B are central horizontal sectional views of a door latch according to an embodiment of the invention installed in a door and having door handle actuators capable of operation by pull or push action; Figures 11A and 11B show inside and outside door handles installed in a door and capable of operation by pull or push action; – 6 – Figures 12A and 12B show inside and outside door handles installed in a door and capable of operation by pull or push action; Figures 13A and 13B show inside and outside door handles installed in a door and capable of operation by pull action; Figures 14A and 14B show inside and outside door handles installed in a door, with push action operation; Figures 15A and 15C show a push-button door handle in isolation with button protruding and depressed, respectively; Figures 15B and 15D show the reverse side of the door handle of Figures 15A and 15C respectively, illustrating internal workings of the actuator mechanism; Figure 16 shows the components of the door handle actuator mechanism of Figure 15 in exploded view; Figures 17A and 17C show a sliding pull-tab door handle in isolation with actuator tab in default and active positions, respectively; Figures 17B and 17D show the reverse side of the door handle of Figures 17A and 17C respectively, illustrating internal workings of the actuator mechanism; Figure 18 shows the components of the door handle actuator mechanism of Figure 17 in exploded view; Figures 19 to 21 are various views of a spring latch adapted for use with push/pull door handle actuators according to an embodiment of the invention; Figures 22A and 22B illustrate adaption of a push/pull door handle actuator according to an embodiment of the invention for use with a rotating action spring latch; Figures 23A and 23B illustrate an adaptor mechanism from Figure 22 in isolation.

Detailed description A push/pull operated magnetic door latch according to and embodiment of the invention is illustrated in the accompanying drawings and described below, along with several versions and variations of door handle actuators and application of push/pull handle actuators to spring latch mechanisms. – 7 – On a note of terminology, features of the door latch assembly, mechanisms and components may be described herein using reference to relative orientations or directions such as left/right, upper/lower, forward/back, and the like. In general such terms are to be understood as referring to the assembled latch mechanism as if it were installed in a door, where the direction in which the latch head extends is considered the 'forward' direction.

Thus, considering the latch head extension direction as forward, the door has left and right faces.

In the description that follows, with regard to door structures in which the door latch may be installed, reference may also be made to the 'inside' or 'internal' and 'outside' or 'external' which are commonly used terms that delineate features that lie to one side or the other of the doorway. It should be appreciated these terms are generally used in a relative sense that does not necessarily imply or import other meanings or features unless clearly stated. Moreover, when considering the door having a forward direction as defined by the latch head extension, the left-hand side may be the 'inside' and the right-hand side may be the 'outside', or vice versa.

Certain features of the door latch mechanism are similar on both sides of the door when installed, while other features may be different for the inside and outside. For example, in the case of a door latch with a privacy mode mechanism each side of the door may have similar user-operated handle actuators but different access to and engagement with the privacy setting mechanism. For ease of reference, similar features of the embodiments that are provided on each side of the door are designated by a reference numeral followed by a suffix 'A' or 'B' corresponding to respective sides of the door. It will be appreciated that A or B may arbitrarily correspond to left or right, inside or outside, unless otherwise stated.

Push/pull handle actuators herein generally refer to latch actuator handles that are operable by the user through pushing and/or pulling in order to operate the latch and open the door. This is in contrast to conventional door latch actuators wherein a twisting or turning action of the handle door handle or knob is required to operate the latch, followed by a push or pull to open the door. Some of the door latch actuators described herein – 8 – permit only one of a push or pull action to operate the latch, while others allow the user a choice of a push or pull action.

A magnetic door latch mechanism 10 according to an embodiment of the invention is seen in an exploded perspective view of its components in Figure 1. The general structure of the door latch 10 comprises an elongate housing having inside and outside latch case components 12 and 14 which, when assembled together, support therein a latch slider 20 comprising an elongate bolt body 21 and bolt sliding tab 30. The inside latch case component 12 has a faceplate 13 at its forward end that lies flush with the swinging edge of a door when installed, in conventional manner. Thus, when installed the rest of the housing and components therein lie within the door structure, apart from the bolt head 22 which selectively protrudes through an aperture in the faceplate 13, as explained below. Inside and outside user-operable actuators 70A, 70B are external to the housing and are disposed to opposite sides of the door.

In the assembled latch mechanism 10 the latch slider 20 is supported for sliding forward and rearward movement, relative to the housing, between retracted and engaged positions. The latch slider 20 is biased toward the retracted position by a bolt return spring 28 which acts between a forward wall of the outside latch case and the bolt body such that, in the absence of external forces, the latch slider remains in the retracted position.

The latch mechanism 10 also includes a strike plate 40 that is operatively installed in a door frame. The strike plate has a strike cavity 42 and a strike magnet 44. The bolt head 22 also contains a magnet 24, wherein the magnetic polarities of the bolt head magnet and strike magnet are arranged to attract one another. As explained further hereinbelow, when the bolt head in use aligns with the strike cavity magnetic forces draw the bolt head magnet toward the strike magnet whereby the latch slider is drawn from the retracted position to the engaged position against the bias force of the bolt return spring.

In the engaged position the bolt head 22 is located in the strike cavity 42. When the bolt head is engaged in the strike cavity the door in which the mechanism is installed is held (closed) relative to the corresponding door frame. – 9 – In order to enable disengagement of the bolt from the strike and therefore permit the door to be opened, a user-operable actuator 70 is provided on each side of the door.

The inside and outside actuators 70A, 70B are generally similar in construction, although in mirror image. Each actuator 70 comprises a handle plate 74 that is attached to the door in predetermined relationship with the latch housing. The handle plate 74 supports a handle 72 for pivotal movement about a vertically oriented pivot pin 78. The handle is biased into a first position by a handle spring 84 and may be pivoted by user action against the spring bias force to a second position. The handle 72 has a handle lever 80 that, when assembled, projects into the latch housing to operative engage with the latch slider. A handle lever spacer 82 is provided between the handle and the lever to allow for installation of the latch mechanism in doors of different thickness, as explained further below.

The latch mechanism 10 also includes a privacy mode selector which includes a privacy push pin 52 disposed to the inside of the door and a privacy stop pin 56 disposed to the outside of the door. The privacy pins 52, 56 attach to a privacy pin inner component 54 that resides within the latch housing and is moveable transverse to the latch slider 20 for selective engagement therewith as described further below. A privacy pin spring 58 exerts a spring bias force on the privacy mode selector.

The door latch mechanism assembled and installed in a door 2 is shown in central horizontal sectional view in Figures 2 and 3, seen with the latch head retracted and extended respectively. The latch housing 15 (comprising the inside and outside latch case components) is secured within a cavity formed in the door structure with the front edge of the faceplate 13 flush with the swinging edge of the door. The latch slider comprising bolt body 21 and bolt sliding tab 30 are supported within the housing for sliding movement forward and rearward. At the rearward extent of the latch slider movement the bolt head is retracted as seen in Figure 2, wherein the front face of the bolt head 22 lies flush with the faceplate and door edge. The inside and outside actuator assemblies 70A, 70B are mounted on respective sides of the door. The privacy push pin 52 protrudes through an aperture in the inside cover 90A so as to be accessible to a user to engage and disengage the privacy mode, explained further below. In this embodiment the inside and outside handles 72A, 72B are operated by pull-action only – 10 – The latch slider is biased toward the retracted position (Figure 2) by the bolt return spring 28 that acts between opposing formations on the outside latch case and the bolt body. However, in use when the door is closed the bolt head 22 aligns with the cavity 42 of the strike plate 40 that is installed in the door frame and, when so aligned a force of magnetic attraction is exerted between the strike magnet 44 and the bolt magnet 24. The strength of the magnets 24, 44 and the bolt return spring 28 are selected so that the force of magnetic attraction is able to overcome the bolt return spring bias force. This causes the bolt head 22 to be drawn into the strike cavity 42, moving the latch slider to its forward extent as seen in Figure 3. This is referred to as the 'engaged' configuration of the latch mechanism.

Each of the bolt body 21 and the bolt sliding tab 30 have a rear wall formation (indicated at 25, 35 respectively). In the engaged configuration the rear wall formations 25, 35 are positioned adjacent the handle levers 80A, 80B that project into the latch housing from the respective inside and outside actuator handles 72A, 72B, as seen in Figure 3 for example. It is engagement between the handle levers 80A, 80B and the respective rear wall formations 25, 35 that effect disengagement of the bolt by use of the actuator handles 72A, 72B as explained below.

Considering the passage mode of the latch (i.e. disregarding the privacy mode selector), either of the inside or outside actuators is capable of disengaging the latch bolt.

Figure 4 illustrates operation of the inside actuator handle 72A to disengage the latch bolt whereas Figure 5 illustrates operation of the outside actuator handle 72B for similar purpose. For reference, comparison is made to Figure 3 showing the latch with bolt engaged.

Referring to Figure 4, in order to disengage the latch and open the door from the inside the user must grasp the handle 72A and pull the protruding portion causing the handle to pivot as indicated by arrow 'A' about the inside pivot pin 78A. This action results in a corresponding pivoting motion of the inside handle lever 80A, causing the end of the inside handle lever to bear against the bolt body rear 25 drawing the latch slider backward to the disengaged configuration as seen in Figure 4. While the bolt is disengaged the user – 11 – can open the door, by pulling or pushing on the door as appropriate. Once the door has been moved so that the bolt head is no longer in alignment with the strike, the magnetic attraction of the bolt head magnet to the strike magnet is not in effect and the latch slider is maintained in the disengaged configuration by the bolt return spring. Although the embodiments of the magnetic latch shown in the drawings and described in detail herein employ a compression spring (i.e. spring 28) to maintain the latch slider in the disengaged configuration when the bolt head is not aligned with the strike, it is also possible to use a magnetic force for this function also. For example, one or more magnets may be provided to form a magnetic attraction (retention force) between the rear of the latch slider and the rear of the latch case. It will be appreciated that the retention force should be less than the force of magnetic attraction of the bolt head to the strike in order that the bolt can engage when required.

Opening the door from the outside is similarly accomplished by pivoting movement of the outside handle 72B as indicated by arrow 'B' about the outside pivot pin 78B, as seen in Figure 5. Corresponding movement of the outside handle lever 80B causes the end to bear against the rear wall formation 35 of the bolt sliding tab 30. As seen in Figure 3, for example, the inside and outside handle levers are separated vertically so as not to interfere with one another. The bolt body and bolt sliding tab are mounted to move together, apart from a small amount of rearward movement allowed by the bolt body before engagement with the bolt sliding tab which allows for disengagement of the privacy mode select mechanism as explained further below. Thus, action of the outside handle lever 80B on the rear of the bolt sliding tab 30 is also effective to draw the latch slider backward to the disengaged configuration, as seen in Figure 5.

Operation of the door latch mechanism privacy mode selector is described hereinbelow with particular reference to Figures 6, 7 and 8. The door latch mechanism 10 installed in a door 2 is shown in Figure 6 with privacy mode engaged, while Figure 7 shows an enlarged view of the privacy mode select mechanism. Privacy mode can only be engaged from the inside of the door with the door closed such that the bolt head 22 is engaged in the strike 40. The privacy mode is engaged by the user pushing on the portion of the privacy push pin 52 that protrudes through the cover 90A of the inside actuator – 12 – 70A. This displaces the privacy pin inner 54 to engage with both the bolt body 21 and bolt sliding tab 30.

The purpose of the engagement between the privacy pin inner 54 and bolt body 21 is to maintain the privacy pin inner component in the privacy engaged position until disengaged by user action. To accomplish this function the privacy pin inner and bolt body have respective rounded detent formations that frictionally engage one another as indicated within a circled region 60 in Figure 7. When so engaged the privacy pin inner 54 is prevented from returning to a disengaged position under action of the spring 28. The engagement of the detent formations is maintained due to the bolt body 21 being connected to the bolt head which is held by magnetic attraction in the strike.

The purpose of the engagement between the privacy pin inner 54 and the bolt sliding tab 30 is to prevent retraction of the bolt sliding tab by action of the outside handle actuator 70B. To accomplish this function the privacy pin inner when in its engaged position fits within a recess of the bolt sliding tab 30, as indicated within the circled region 62 in Figure 7, which prevents rearward movement of the bolt sliding tab. As noted above the outside actuator handle lever 80B acts upon the rear 35 of the bolt sliding tab 30, and thus with the privacy pin mechanism engaged the outside actuator is unable to operate to disengage the latch bolt.

The privacy pin mechanism can be disengaged in several ways, and reference is additionally made to Figure 8 for the purposes of explanation.

One way of disengaging the privacy mode is by a user pulling on the inside privacy pin 52 in the direction indicated by arrow 'D1' in Figure 8, the action of which is simply opposite to the way in which the privacy mode is engaged. Although the bolt sliding tab 30 is prevented from moving while the privacy pin inner 54 is in the engaged position, the bolt body 21 is able to move backwards by a small amount corresponding to the gap between these two components as indicated within the circled region 64 in Figure 7. This small translation of the bolt body is sufficient to allow for the engagement of detent formations between the privacy pin inner 54 and the bolt body 21 to be released. The rounded shape of the detent formations means that the contact between them when – 13 – engaged is angled so that the action of pulling on the inside privacy pin 52 is able to force the bolt body backward and release the engagement. Once the privacy pin mechanism is in the disengaged position the bolt body 21 and bolt sliding tab 30 are able to move together.

Similar to pulling on the inside privacy pin 52, the privacy mode may also be disengaged by a user pushing on the outside privacy pin 56 in the direction as indicated by arrow 'D2' in Figure 8. In practice the outside privacy pin 56 may only be accessible through a small and/or concealed hole in the outside cover 90B.

The latch mechanism also allows for the privacy mode to be disengaged by a user operating the inside handle 72A, such as indicated by arrow 'D3' in Figure 8. As explained above, pivotal movement of the inside handle causes the inside handle lever 80A to bear upon the bolt body rear portion 25 in a rearward direction. As also noted above, the arrangement of the bolt body 21 and the bolt sliding tab 30 allows a degree of displacement of the bolt body while the bolt sliding tab remains held in place by the privacy pin inner 54. This first degree of displacement initiated by operation of the inside handle 72A is illustrated in Figure 8 and is sufficient to clear the engagement between the detent formations on the bolt body and privacy pin inner. Once the bolt body detent is clear of the privacy pin inner detent the privacy pin mechanism is returned to its disengaged configuration by action of the spring 58. Further pivotal motion of the inside handle operates to draw the bolt back into a disengaged position in order to open the door as previously described.

The latch mechanism 10 is designed to allow for it to be readily installed in doors of different thickness, as illustrated in Figures 9A and 9B. In Figure 9A a first version of the door latch 10' is shown installed in a door 2' having a relatively small thickness (e.g. of the order of 32-43mm thick). In Figure 9B a second version of the door latch 10" is shown installed in a door 2" having a relatively large thickness (e.g. of the order of 43-50mm thick). The only difference in componentry as between the first and second versions of the door latch is the length of the handle lever spacers, as can be seen in comparison of the handle lever spacers 82A' and 82A" indicated in the drawings. For installation in a relatively thin door the installer may use a small handle lever spacer resulting in a – 14 – relatively short handle lever length. Conversely, for installation in a relatively thick door the installer may use a large handle lever spacer resulting in a relatively long handle lever length. The remainder of the latch mechanism components may remain the same for each door thickness.

Although the preceding description refers to user-operable actuators that function by a pulling action, as noted hereinabove the magnetic latch mechanism 10 disclosed herein may incorporate user-operated actuators that function either by pushing and/or pulling. In particular, Figures 10A and 10B show a latch mechanism 10 installed in a door and equipped with actuators each having a handle that may be operated by a push or pull action according to user preference. Figure 10A shows the latch 10 with the bolt engaged and Figure 10B shows the outside handle 70B in operation to retract the bolt. As seen, the actuator in this case has both a handle pull portion 72 (similar to the handle previously described) and also a handle push portion 73 located closer to the front of the door. So that the pull portion and push portion of the handle can both operate the latch mechanism in the same way, the handle pivot pin 78 is positioned in between. Referring particularly to Figure 10B, the pull handle portion is operable to disengage the latch bolt by pulling on the rearwardly projecting portion 72 to pivot the handle in the direction generally indicated by arrow 'P1', while the push portion of the handle is operable by pushing on the portion 73 in the direction generally indicated by arrow 'P2'. Either action is effective to pivot the attached handle lever 80 about the pivot pin to bear on the rear of the latch slider as previously described.

Figures 11, 12, 13 and 14 show several different door handle configurations that may be employed with latch mechanisms according to embodiments of the invention, as they would appear installed on a door.

Figure 11 shows a 'rocker-switch' style similar to that described above in connection with Figure 10 – Figure 11A shows the inside actuator 70A and Figure 11B shows the outside actuator 70B. As previously described, in this embodiment the actuator 70 can be operated by a user either by pulling on the handle portion 72 or by pushing on the handle portion 73. The actuators illustrated in Figures 12A and 12B operate in the same way, although the shape is somewhat different. – 15 – Figure 13 shows a pull-only operated handle style – Figure 13A shows the inside actuator 70A and Figure 13B shows the outside actuator 70B. In this embodiment the actuator 70 can be operated by a user to disengage the latch bolt only by pulling on the handle portion 72.

Figure 14 shows a push-only operated handle style – Figure 14A shows the inside actuator 70A and Figure 14B shows the outside actuator 70B. In this embodiment the actuator 70 can be operated by a user to disengage the latch bolt only by pushing on the handle portion 73. In order to allow the user to pull the door open (as required from one side) once the latch bolt has been disengaged, a protruding lip that may be grasped by the user is formed on the rear edge of the actuator plate 74.

Figures 15 and 16 present several views of a 'push-button' actuator that functions similarly to that seen in Figure 14. Specifically, Figures 15A and 15C show a push-button actuator in isolation with button protruding and depressed, respectively. Figures 15B and 15D show the reverse side of the actuator corresponding to Figures 15A and 15C respectively, illustrating internal workings of the actuator mechanism. Figure 16 shows the components of the door handle actuator mechanism of Figure 15 in exploded view.

Figures 15A-15D illustrate action of the actuator mechanism whereby depression of the push-button portion of the handle 73 effects pivotal displacement of the handle lever 80 about the axis of the pivot pin 78. The handle is biased to its resting position (e.g. as seen in Figures 15A and 15B) by the spring 84.

The actuators described above all utilise a pivoting action to translate movement of the user operated handle portion into movement of the handle lever which operates the latch mechanism, however the linear motion of the latch mechanism also enables linear action handles to be used. An example of an actuator with a linear action handle is shown in Figures 17 and 18. Specifically, Figures 17A and 17C show a sliding pull-tab actuator in isolation with tab in resting and displaced positions, respectively. Figures 17B and 17D show the reverse side of the actuator corresponding to Figures 17A and 17C respectively, illustrating internal workings of the actuator mechanism. Figure 18 shows the components of the door handle actuator mechanism of Figure 18 in exploded view. In this – 16 – embodiment, the handle has a sliding pull-tab 75 that may be manipulated by the user's thumb, for example, from the position shown in Figure 17A to the position shown in Figure 17C. Rather than the pivoting action as previously described the handle has a sliding action, wherein the handle is supported for sliding movement between the handle plate 74 and a back plate 76. The handle 'lever' 80 projects inwardly from the handle to in use engage with the rear of the latch slider, although it will be appreciated that in this instance the end of the handle lever will describe a linear path rather than an arcuate path as for the pivoting handle embodiments.

Although the preceding description of embodiments of the invention have been in the context of a magnetic door latch, the principles of the push/pull door latch actuators can also be applied to operate a more conventional spring latch with some modification. A simple modified spring latch mechanism that may be used with push/pull actuators as disclosed herein is shown in various views in Figures 19-21. Specifically, Figures 19A and 19B are front perspective views of a spring latch 100 seen with bolt extended and retracted, respectively; Figures 20A and 20B show the spring latch 100 in horizontal cross-section with the bolt extended and retracted; and Figure 21 shows the components of the spring latch 100 in exploded view.

The spring latch 100 has a latch casing assembly 110 with a forward faceplate 112 that is in use secured to the front edge of a door with the remainder of the casing assembly supporting within a cavity formed in the door structure in known fashion. A bolt head 122 is supported by the latch casing assembly to protrude from an aperture 113 in the faceplate, and has an angled surface on one side that is adapted in use to contact a strike plate in conventional manner. A bolt return spring 128 is provided within the latch casing assembly to urge the bolt head to an extended position in which it protrudes from the faceplate aperture, wherein the bolt head can also be forced, such as by impact with the strike plate, against the spring bias force into a retracted position within the latch casing assembly.

Where a conventional spring latch mechanism includes some form of cam or lever arm mechanism to translate a door handle twisting action into a linear motion of the bolt head, the spring latch 100 instead has a latch slider 120 that is coupled to the bolt head – 17 – 122 and includes left and right actuator engagement tabs 130A, 130B that project laterally from openings toward the rear of the latch casing assembly. The coupling between the latch slider 120 and bolt head 122 is such that rearward displacement of the latch slider effects retraction of the bolt head. In use, rearward displacement of the latch slider is brought about by one or other of the inside and outside push/pull actuators acting upon a corresponding one of the actuator engagement tabs. For example, referring to the previously described embodiments of push/pull actuators, the spring latch 100 is in use mounted with such actuators arranged so that the inside and outside handle levers 80A and 80B can engage with the respective actuator engagement tabs 130A, 130B. The spring latch 100 as seen operates in passage mode only and does not include a privacy mode mechanism.

Figures 22A and 22B illustrate a system by which a push/pull door handle actuator according to an embodiment of the invention may be adapted for use with a conventional rotating action spring latch. Figures 23A and 23B illustrate in isolation an example of an adaptor device as employed in the system of Figure 22. In particular, a convention form of rotating action spring latch 150 is shown, having a bolt head 152 that is retractable by rotational displacement of a hub 154 (ordinarily through engagement with a rotatable door handle). An actuator adapter 160 is provided with a spindle 162 that engages with the hub 154. The spindle supports an adapter disk 164 having a radially formed conversion slot 166. In use, the handle lever 80 of the push/pull actuator 70 engages in the conversion slot 166 whereby the linear or horizontal sweeping motion of the lever 80 drives a rotating motion of the adapter disk, resulting in rotating action of the hub 154.

The application of push/pull door handle actuators to spring latches, as seen in Figures 19-23 for example, has been simplified for ease of explanation of the operating principles. Nevertheless it may be readily recognised that a spring latch, whether linear or rotating action, adapted for use with a push/pull handle actuator according to embodiments of the invention may include additional features not shown in the drawings, to provide privacy mode functionality and the like.

The invention has been described by way of non-limiting example only and many modifications and variations may be made thereto without departing from the spirit and – 18 – scope of the invention. It may also be noted that while operational and functional components of the embodiments have been described and illustrated, various fasteners that may be used to secure the components together and to the door and door frame structure have been omitted in the interest of simplicity.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. – 19 –

Claims (13)

CLAIMS 1.:

1. A push/pull action user-operable actuator for a door latch mechanism mounted within the structure of a hinged or swinging door, comprising: 5 a mounting member adapted for mounting on a door in relation to the door latch; a handle member pivotally supported by the mounting member for movement between a resting position and an operative position; a lever arm coupled to the handle member and extending into the door structure for operative engagement with the door latch, wherein pivotal movement of the handle 10 member from the resting position to the operative position effects swinging motion of the lever arm for actuation of the door latch, in use.

2. A push/pull door latch actuator according to claim 1 wherein the handle member is pivotally supported by the mounting member for pivotal movement about a vertical axis.

3. A push/pull door latch actuator according to claim 1 or claim 2 wherein the handle member includes a handle pull portion or a handle push portion or both a handle pull portion and a handle push portion, and wherein the handle member is user-operable for movement between the resting position and the operative position by pulling and/or 20 pushing on the handle member as appropriate relative to the face of the door.

4. A push/pull door latch actuator according to any one of claims 1 to 3 including a spring arranged to apply a bias force to urge the handle member into the resting position in the absence of user action.

5. A latch mechanism for a hinged or pivoting door, comprising: a housing adapted for mounting in or on a door; a latch slider supported by the housing for reciprocating movement between an extended position and a retracted position, the latch slider including a latch head having a 30 magnetic component; a biasing means acting on the latch member to apply a bias force to the latch member toward the retracted position; – 20 – wherein the latch slider is operatively drawn to its extended position by magnetic force when the latch head in use aligns with a magnetically susceptible strike member mounted on a corresponding door fixture; and wherein the latch slider includes an actuator engagement member adapted to 5 engage with a lever arm of a push/pull user-operable actuator to in use effect retraction of the latch slider in opposition to said magnetic force.

6. A latch mechanism according to claim 5 including a privacy mode selection mechanism having a privacy engagement member moveable between a first position and 10 a second position, wherein the privacy engagement member when in the second position engages with the latch slider to prevent retraction of the latch slider.

7. A latch mechanism according to claim 6 wherein the privacy mode selection mechanism includes a user operable privacy pin coupled to the privacy engagement 15 member to enable movement of the privacy engagement member between the first and second positions.

8. A latch mechanism according to claim 7 wherein the privacy pin and privacy engagement member are moveable transverse to an axis of movement of the latch slider.

9. A latch mechanism according to any one of claims 5 to 8 wherein the biasing means comprises a compression spring.

10. A latch mechanism according to any one of claims 5 to 8 wherein the biasing 25 means comprises at least one magnet.

11. A door latch assembly including a latch mechanism according to any one of claims 5 to 10 together with at least one push/pull door latch actuator according to any one of claims 1 to 4.

12. A door latch assembly according to claim 11 including first and second push/pull door latch actuators operatively mounted to a door on opposite sides of the door latch mechanism wherein the first and second lever arms of the respective first and second – 21 – actuators are vertically displaced from one another to permit independent swinging motion thereof in use.

13. A door latch assembly including a latch mechanism according to any one of claims 5 5 to 10 together with at least one sliding tab door latch actuator comprising: a mounting member adapted for mounting on a door in relation to the latch mechanism; a handle member supported by the mounting member for sliding movement between a resting position and an operative position; 10 an actuator arm coupled to the handle member and extending into the door structure for operative engagement with the latch mechanism, wherein sliding movement of the handle member from the resting position to the operative position effects linear motion of the actuator arm for actuation of the latch mechanism, in use. – 22 –