GB2580393A - Vehicle door latch assembly - Google Patents

Abstract

A vehicle door latch assembly comprising a handle 211 (lever 305, fig.3a) coupled to a latch 210 via a mechanical linkage 213 and a circuit 212 having a sensor (306, fig.3b) operating an electric actuator (402, fig.4a) providing electronic release. The sensor operates the electric actuator in response to a force in a first direction and the handle is movable in a second direction different to the first direction. The first and second directions may be orthogonal such that the handle may be pivoted downwards and the sensor may be actuated by pulling outwards on the door handle, the sensor may be located on the handle. The force to move the handle manually may be greater than the force to actuate the sensor. The handle may include a detent to retain the handle in a rest position. The sensor may be a button switch or capacitive touch-responsive sensor. The handle may be hidden from view behind a door panel.

Description

VEHICLE DOOR LATCH ASSEMBLY

Field of the Invention

The present invention relates to a latch assembly for releasably latching a door of a vehicle.

Background of the Invention

Vehicle doors are usually provided with a latch assembly for releasably latching the door in the closed position. The latch assembly usually comprises a striker mounted to the door frame, a latch movably mounted to the trailing edge of the door for releasably engaging the striker, and a handle mounted to the door that is movable by a user to actuate the latch to disengage the striker. Conventionally the latch assembly comprises a mechanical linkage connecting the handle to the latch. More recently electronic release latch assemblies have been developed in which an electronic trigger is provided for operation of an electric actuator which in mm actuates the latch.

Electronic release, e-release', systems have a number of operational advantages over conventional mechanical release systems. For example, e-release systems provide a relatively 'light' operation, because the user is only required to operate the electronic trigger, for example, to throw a switch or trigger a touch-responsive sensor. This light operation may be preferred by a user for its ease of use and perceived refinement Further, an errelease system may be configured to require only a short travel of a release member, for example, to cause the throw of a switch between its two states, or indeed in the case of a touch-responsive sensor, no travel at all. This short travel may similarly allow easy operation of the system by a user, and additionally may permit location of the release trigger in a relatively small space.

An errelease system however is reliant for its operation on an electrical power supply, and it will cease to function if the power supply is interrupted. Failure of a door latch release is likely to inconvenience or even endanger the vehicle user. Accordingly, it is advantageous that latch assemblies incorporating an e-release system as a primary release function further include a mechanical release system as a backup to facilitate mechanical actuation of the latch in the event of failure of the e-release system.

One approach to employing a door latch assembly with both e-release and mechanical release functions is shown in US 8,915,524 B2 where a first handle is provided for operating the e-release systems and a second handle for operating the mechanical release systems. An alternative approach is shown in DE 10 2014 117 005 Al in which a common handle is movable through a first extent of travel to operate the e-release system and further movable through a second extent of travel to operate the mechanical release system.

Summary of the Invention

A first aspect of the invention provides a door latch assembly comprising a handle, a latch having a locked position and an unlocked position, a mechanical linkage connecting the handle to the latch, an electric actuator connected to the latch, and a sensor for operating the actuator, wherein the sensor is arranged to operate the actuator to move the latch from the locked to the unlocked position in reaction to a first force exerted on the handle in a first direction, the handle is movable in a second direction to act on the linkage to move the latch from the locked to the unlocked position in reaction to a second force exerted on the handle in the second direction, and the first direction is different to the second direction.

The provision of e-release systems, i.e. the sensor and electric actuator pair, and mechanical release systems, i.e. the mechanical linkage, for unlocking the latch advantageously combines the ease of use, improved refinement and packaging benefits of an e-release function with the operational resilience of a mechanical release function. The door latch assembly of the present invention may thus usefully be operated such that the e-release system is used by a user as a primary release function for unlocking the latch, thereby benefitting from the associated ease of use and improved refinement characteristics in normal operation, whilst the mechanical release function may serve as a backup usable in the event of failure of the e-release function.

In the latch assembly of the present invention the e-release and mechanical release systems are operable by a conunon handle. As a result the need for a separate second handle to operate the mechanical release system is avoided. Consequently the latch assembly is relatively compact and structurally simple. In contrast, the separate handles of the latch assembly shown in US 8,915,824 B2 occupy additional volume, incur additional material expense, and add mass and complexity to the assembly.

Moreover, because the e-release and mechanical release systems of the door latch assembly of the present invention are operated by forces applied to the common handle in different directions, the risk of inadvertent operation of either system is reduced.

Consequently the likelihood of damage or malfunction being caused to the latch assembly by simultaneous operation of both the errelease and mechanical release systems is reduced. In contrast, with the latch assembly shown in DE 10 2014 117 005 Al. because the e-release and mechanical release systems are operated by movement of the handle in the same direction, it may be too easy for a user intending to operate only the e-release system to exert too great a force on the common handle and inadvertently also operate the mechanical release system. Such simultaneous operation of both release systems could disadvantageously result in damage to the latch assembly or otherwise cause its malfunction.

Further, with the latch assembly of the present invention the movement of the handle to operate the mechanical release systems is in the second direction rather than in the first direction. As a result, the extent of movement of the handle in the first direction may be reduced. Consequently, the handle may acceptably be located in a space having a relatively low dimension in the first direction. By way of example, this may permit the handle to be oriented in a space such that the e-release system is operated by application of a force to the handle in the direction of a minor dimension of the space, which may be a preferred direction for applying a force to the handle, because the handle may then be movable to operate the mechanical release system in the different direction of a major dimension of the space. In contrast, in the latch assembly shown in DE 10 2014 117 005 Al the travel of the handle in the common direction may tend to be relatively great, it being the sum of the travel required to operate the e-release system plus the travel required to operate the mechanical release system. This disadvantageously requires that the handle is packaged in a space having a correspondingly large dimension in the direction of travel of the handle.

By way of example, the handle may be arranged to exert a force on the sensor to operate the actuator to move the latch from the locked to the unlocked position in reaction to a first force exerted on the handle in the first direction. As an exemplary alternative, the handle may be an-anged to move in reaction to a first force exerted on the handle in the first direction, and the sensor may be arranged to sense such movement of the handle and in response operate the actuator to move the latch from the locked to the unlocked position.

The latch assembly may be configured such that the first direction and the second directions are nonparallel. In particular, the first and second directions may be mutually orthogonal. That is to say, the latch assembly may be configured such that the handle acts on the sensor in reaction to a force in the first direction, and acts on the mechanical linkage in reaction to force in a direction in a non-parallel, and preferably orthogonal, direction. This may further reduce the likelihood of inadvertent operation of either of the e-release and mechanical release systems because the likelihood of a user inadvertently applying to the handle mutually non-parallel or orthogonal forces may be expected to be low. As a result occurrences of damage or malfunction associated with simultaneous operadon of the e-release and mechanical release systems may be reduced. The first direction may be in a generally horizontal direction and the second direction in a generally vertical direction.

It should he understood that in the context the term 'orthogonal' mean approximately, rather than geometrically exactly, orthogonal. In particular, with the stated aim of reducing the likelihood of inadvertent operation of either of the e-release or the mechanical release systems, it will be appreciated that it is not necessary that the two directions extend exactly mutually orthogonally to achieve the advantage.

The assembly may be adapted such that the second force required ' the latch from the locked position is greater than the first force required to move the latch from the locked position. For example, the latch assembly may comprise a brake acting on the handle or on the mechanical linkage for resisting movement of the handle in the second direction.

For example, the brake may comprise a member arranged to exert frictional resistance on the mechanical linkage or on the handle, or alternatively could comprise a spring arranged to bias the handle to a rest position and to be tensioned by movement of the handle away from the rest position. In this arrangement it is thus easier for the user to operate by the handle the e-release systems and harder to operate the mechanical release systems. Consequently the handle is in effect biased towards operation of the e-release systems and against operation of the mechanical release systems. As a result the likelihood of inadvertent operation of the mechanical release systems by a user is reduced. In particular, in this arrangement a force applied to the handle in a direction between the first direction and the second direction will advantageously tend to operate the e-release systems in preference to the mechanical release systems.

The handle may be movable in the second direction between a rest position and an operative position, the assembly may comprise a detent that retains the handle in the rest position, and the detent may be adapted to release the handle for movement towards the operative position only when the second force exerted on the handle exceeds a threshold force. The rest and operative positions of the handle may correspond to the locked and unlocked positions respectively of the latch. The detent may act on the mechanical linkage or on the handle directly. The detent may thus act to resist movement of the handle in the second direction so inhibiting operation of the mechanical release system.

As a result the risk of inadvertent operation of the mechanical release system is reduced.

The detent may act to exert a retaining force on the handle that is maximal when the handle is at the rest position but minimal as soon as the handle is released for movement to the operative position. Consequently the handle is effectively retained in the rest position by the detent but when released is easily moved to the operative position.

It should be understood from reading this specification as a whole that a number of detent mechanisms may suitably function to retain the handle in the rest position. Fundamentally, what is required is means for retaining the handle in the rest position until acted on by a force acting in the second direction exceeding a threshold, at which time the handle is released by the detent to move in the second direction towards the operative position. In the specific example of the invention described herein the detent takes the form of a catch which engages the handle to retain the handle in the rest position and which is configured to deform elastically under an applied load exceeding a predetermined threshold to permit disengagement from the handle so releasing the handle for movement to the operative position. As an exemplary alternative however a breakable member could be provided which, when intact acts to retains the handle in the rest position, and which is configured to break sacrificially when acted on by a force exceeding the threshold to release the handle for movement to the operative position.

The detent may be adapted to release the handle for movement in the second direction only when the second force exceeds 50 N. That is to say, the detent may be adapted to retain the handle in the rest position until a force having a component exceeding 50 N in the second direction is applied to the handle. Consequently movement of the handle in the second direction towards the operative position is prevented even if subjected to a incidental forces acting in the second direction below this threshold. As a result the risk of inadvertent operation of the mechanical release systems is further reduced.

A threshold of 50 N is considered to represent a good balance between requiring a force that is sufficiently high such that the handle would not be expected to be subjected to incidental forces of that magnitude, so avoiding inadvertent operation of the mechanical release systems, yet not so high as to make it prohibitively difficult for a user to intentionally operate the mechanical release systems. It will be appreciated in this respect however that the particular threshold of 50 N represents a lower bound to a range of thresholds thought to represent a good balance between the above factors for the specific application desaibed in detail herein, namely, for a door of a passenger car.

It should be appreciated though that in other applications, for example, in applications where it is expected that the handle may be subjected to incidental forces in the second direction exceeding 50 N, the detent may be adapted to present a greater retaining force. For example, in alternative applications the detent may he adapted to release the handle for movement in the second direction only when the second force exceeds one of the higher thresholds of 75 N. 100 N. 125 N, 150 N, 200 N, or even greater still.

The sensor may be mounted on the handle. In this arrangement a user grasping the handle may in a single action trigger the sensor to operate the actuator and exert a pulling or pushing force on the handle to open a door to which the handle is attached. In particular, mounting the sensor to the handle may make the sensor more responsive to a user grasping the handle and reduce the force required to be exerted by a user on the handle in the first direction to trigger the sensor. As an exemplary alternative the sensor could he provided separately to the handle and the handle could he movable also in the first direction in reaction to the first force exerted on the handle in the first direction to act on the sensor to operate the actuator.

In an embodiment described in detail herein the sensor is a switch capable of switching electrical current. In an alternative embodiment the sensor could be a non-switching device arranged to sense a force exerted on the handle in the first direction. Such a non-switching device could in turn co-operate with a switch operable to switch electrical current to selectively energise the electrical actuator. For example, the sensor could alternatively comprise a device with electrical characteristics which change in reaction to a force exerted on the handle in the first direction, and the change in electrical characteristics of the sensor could be used as trigger to throw a switch to selectively energise the electrical actuator The sensor may he a touch-responsive, or tactile, sensor. That is to say, the sensor may be responsive to mere contact by a user. A touch responsive sensor may allow easier operation of the electric actuator by the user and may improve the perceived refinement and mechanical resilience of the latch assembly.

The sensor may be a capacitive sensor. A capacitive sensor may advantageously provide reliable and consistent operation.

The latch assembly may further comprise a striker for releasable engagement by the latch. The latch and striker may thus co-operate to create a releasable connection between two relatively movable parts of a closure.

A second aspect of the present invention provides a vehicle comprising a door, a door frame and a door latch assembly according to any one of the preceding statements, wherein the door is movable relative to the door frame between a closed position and an open position, and the handle is mounted to the door. Mounting the handle to the door allows the handle to be manipulated to release the door latch assembly and for the door to be opened by a force exerted on the handle.

The first direction may be in the direction of movement of the door from the closed position to the open position, i.e. in a generally horizontal direction. That is to say, the handle may be mounted to the door in an orientation such that a force applied to the handle in the direction of opening of the door will operate the e-release system. Consequently, operation of the e-release system and opening the door of the vehicle may be performed by a user by a single intuitive action on the handle. By way of example, this effect could be achieved by locating the sensor on an inner side of the handle, i.e. on a side of the handle that faces in the opposite direction to the direction of opening of the door. Alternatively, the handle could be arranged to move relative to the door in the direction of opening of the door to act on the sensor.

The second direction may be downwards, that is to say, in the generally vertical, or direction, of of the door. Applying a downwards force to the handle is unintuitive in the action of opening the door from its frame outwards. It is thus expected that a user is unlikely to inadvertently exert a downwards force on the handle, for example, in the course of attempting to open the door using the e-release system. Consequently the likelihood of the mechanical release system being inadvertently operated is reduced.

Furthermore, the travel of the handle in the second direction required to operate the mechanical release system may be relatively great, and the Y-direction of the door may comprise a sufficiently large space to accommodate the handle throughout its travel. The door may comprise a door panel having an aperture and the handle may be located behind the door panel at a position above the aperture.

In this arrangement the handle is separated from the exterior of the door by the door panel. The handle is therefore hidden from the view of a user observing the door. Consequently the aesthetic of the door may he improved. Moreover, the door panel may shield the handle from an airflow passing over the exterior surface of the door.

Consequently aerodynamic drag exerted on the door as it moves through an airflow may be reduced. A user standing beside the door may still however access the handle via the aperture to facilitate actuation of the latch.

A problem however associated with locating the handle behind the door panel is that because the handle is hidden from the view of a user the handle may be susceptible to accidental use by a user in the course of exerting a pulling force on the door. This could result in inadvertent actuation of the latch from the locked to the unlocked positions. Inadvertent actuation of the latch could result in damage to the latch assembly or otherwise cause its malfunction. But movement of the handle downwards is unintuitive in the action of opening the door outwards. It is thus expected that a user is unlikely to inadvertently exert a downwards force on the handle sufficient to move the handle downwards in the course of opening the door. Therefore in this arrangement the likelihood of the latch assembly being damaged through inadvertent actuation of the latch is reduced.

Furthermore, the Z-direction dimension of the door, that is the depth of the door, may tend to be relatively small to avoid excessive intrusion of the door into the space it closes. Conversely, the travel of the handle required to act on the mechanical linkage to move the latch from the locked position to the unlocked position may tend to be relatively great, typically at least equal to the throw of the latch. Where the handle is located behind the door panel, that is within the door, travel of the handle in the Z-direction of the door could be unacceptably limited by the door panel, or conversely an unacceptable increase in the Z-direction depth of the door may he required to accommodate the travel of the handle in the Z-direction. However, movement of the handle downwards, that is generally in the Y-direction of the door, reduces the Z-direction space required to be provided to accommodate the handle. Consequently the handle may be located in a space having a relatively small Z-direction space.

The latch may be mounted to the door and the striker may be mounted to the door 10 frame. Consequently the connection between the handle and the latch is simplified.

Brief Description of the Drawings

In order that the present invention may he more readily understood, embodiments of the invention will now he described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic aerial view of a vehicle comprising a door and a latch assembly therefor embodying the present invention; Figures 2a and 2b are side and end elevation views respectively of the door showing schematically the door handle assembly, latch mechanism, electrical circuit and mechanical linkage of the door latch assembly; Figures 3a, 3b and 3c are outer side, inner side and end views respectively of the door handle assembly showing the handle in rest and operative positions; Figures 4a and 4h show schematically the latch mechanism showing the latch thereof in its locked and unlocked positions respectively; Figures 5a and 5b depict the door schematically in end cross-sectional views showing a user applying to the door handle assembly a first force acting in a first direction to operate an actuator of the latch mechanism to move the latch of the latch mechanism from its locked to its unlocked position; and Figures 6a and 6b depict the door schematically in end cross-sectional views showing a user applying to the door handle assembly a second force acting in a second direction to act on the mechanical linkage to move the latch of the latch mechanism from its locked position to its unlocked position.

Detailed Description of the Invention

Referring firstly to Figures 1, 2a and 2b, a vehicle, which in the example takes the form of a passenger car 101, comprises a body structure 102 defining a passenger cabin 103 for accommodating passengers. The body structure 102 comprises 'A', '13' and 'C' pillar pairs 104, 105, 106, which together with floor 107 and roof (riot visible in the Figures) structures form frames to door openings, such as door opening 108, in the side of the body structure 102 to permit passenger ingress and egress from the cabin 101 The car 101 further comprises a plurality of doors 109, 110, 111, 112, each hingedly connected to the body structure 102 adjacent a respective door opening to selectively close the door (Telling. Each door 109 to 112 is provided with a door latch assembly, such as door latch assembly 201 associated with door 109, for releasably latching the door in a closed position relative to its respective door opening.

Each of the doors 109 to 112 is substantially alike, as is the operation of the latch assembly of each door. For brevity therefore only door 109 and latch assembly 201 will be described in detail herein, on the understanding that the same teachings are applicable to doors 110 to 112 and their associated like latch assemblies.

Door 109 is hingedly mounted a its leading edge 202 to A-pillar 104a for hinged movement relative to the door opening 108 in the outward direction Z between a closed 30 position in which the door closes the door opening 108, and the open position illustrated in Figure 1 in which the door is moved clear of the door opening to permit passenger ingress and egress from the passenger compartment. The door 109 comprises an outer panel 203 forming an exterior surface of the vehicle, an inner panel 204 forming an interior surface of the vehicle bounding the passenger cabin 103, and a window pane 205. The outer panel 203 has an inwardly concave portion which forms an undercut 206 extending along the length of the door. An aperture 207 is formed in the roof of the undercut portion 206 extending through the outer panel 203. A well 208 is formed within the space between the outer panel 203 and the inner panel 204 above the aperture 207 and open at its lower end to the aperture 207.

The door latch assembly, indicated generally at 201, comprises a striker 209, a latching mechanism 210 for releasably engaging the striker 209, a handle assembly 211 for actuating the latching mechanism 210 to disengage the striker 209, an electrical circuit 212 electrically connecting the handle assembly 211 to the latching mechanism 210, and a mechanical linkage 213 mechanically connecting the handle assembly 211 to the latching mechanism 210.

The striker 109 is mounted to the forward edge of the B-pillar 105a and projects into the door opening 108. The striker 109 has a generally U-shaped form comprising a pair of parallel posts joined at their base ends to the B-pi I lar 105a. The latching mechanism 210 is mounted to the trailing edge 214 of the door 109 and comprises a movably canied latch 215. The latch 215 is movable between a locked position in which the latch 215 engages the striker 209 to latch the door in the closed position, and an unlocked position in which the latch 215 disengages the striker 209 to allow the door to be opened. The striker 209 and the latching mechanism 210 will be described in further detail with particular reference to Figures 4a and 4b.

The handle assembly 211 is mounted to the door within the well 208 and is accessible through the aperture 207 in the outer body panel 203 to a user standing outside of the vehicle. The handle is arranged to be manipulable by a user outside of the vehicle for actuation of the latch 215 of the latching mechanism 210 between its locked and unlocked positions via the electrical circuit 212 and the mechanical linkage 213. The handle assembly 211 will be described in further detail with reference to Figures 3a to 3c.

The electrical circuit 212 is adapted to transmit an electrical signal between the handle assembly 211 and the latching mechanism 210 to permit electric actuation of the latch 215 of the latching mechanism 210 by the handle assembly 211. In the example, the electrical circuit 212 comprises electrical wires 216, 217 for carrying electrical current and an electrical control unit 218 adapted to receive an input electrical signal from the handle assembly 211 indicating an 'unlock' operation performed on the handle assembly 211 by a user, process the electrical signal, and transmit a corresponding electrical 'unlock' signal to the latching mechanism 210 to cause the latch 215 to be moved to its unlocked position.

The mechanical linkage, indicated generally at 213, is arranged for transmitting mechanical force between the handle assembly 211 and the latch 215 of the latching mechanism 210 to permit mechanical actuation of the latch 215 of the latching mechanism 210 by the handle assembly 211. In the example, the mechanical linkage 213 comprises a Bowden cable connected at one end to the handle assembly 211 and at the other end to the latch 215. The mechanical linkage 213 thus acts to translate an 'unlock' movement of the handle assembly 211 by a user to movement of the latch 215 to its unlocked position.

Because the handle assembly 211 is connected to the latching mechanism 210 via both the electrical circuit 212 and the mechanical linkage 213, the latch 215 may be actuated by the handle assembly 211 either electrically or mechanically. This has the advantage that in normal operation the latch 215 may be actuated by the handle assembly 211 electrically via the electrical circuit 211 hut in the event of failure of the electrical circuit 212 the mechanical linkage 213 may be used to mechanically actuate the latch 215 by the handle assembly 211. The operation of the electrical circuit 212 and the mechanical linkage 213 will be described further with reference to Figures 5a, 5b, 6a and 611.

Referring next in particular to Figures 3a, 3b and 3c, the handle assembly 211 comprises a support plate 301 and a handle 302 movably mounted to the support plate 301.

The support plate 301 is adapted for rigid mounting to the door 109 of the vehicle by fasteners penetrating through the support plate into the structure of the door. The support plate 301 has an inner side 303 which in the installed condition shown previously in Figure 2b is arranged to face inwardly of the vehicle and an outer side 304 arranged to face outwardly of the vehicle against a surface of the well 208 of the door 109.

The handle 302 comprises a lever 305 and a sensor assembly 306. The lever 305 is pivotally mounted to the support plate 301 proximal a first end by pivot pin 307 which permits rotational movement of the handle 302 relative to the support plate 301 in the Y-direction between a rest position '12' and an operative position '0'. The pivot pin 307 substantially prevents movement of the lever 305 relative to the support plate 301 in the Z-direction such that a Z-direction force applied to the lever 305 is transmitted to the support plate 301.

The sensor assembly 306 is disposed on an inner side of the lever 305. The sensor assembly 306 comprises a base part 307 fixed to the inner side of the lever 305, a relatively movable switch plate 308 movably carried by the base part 307, and an electrical switch device 309 mounted to the base part 307 and located between the base part 307 and the switch plate 308. The switch plate 308 is movable relative to the base part 307 in the Z-direction between the illustrated un-pressed position in which the switch plate 308 is clear of the switch device 309 and a de-pressed position in which the switch plate 308 acts on the switch device 309. The switch plate 308 is biased to the unpressed position by a biasing spring (omitted from the Figures) which acts between the base part 307 and the switch plate 308. Thus in reaction to a force acting in the Z-direction exerted by a user on the switch device 309 via the switch plate 308, the lever 305 exerts a conesponding counter force on the switch device 309 via the base plate 307.

The switch device 309 is a momentary action push to make switch. The switch device 309 is electrically coupled to the electrical circuit 212 and is configured to complete an electrical connection of the electrical circuit 212 when acted on by the switch plate 308. The electrical controller 218 is configured to interpret a circuit made by the switch device 309 as an 'unlock' command and transmit a corresponding 'unlock' signal to the latching mechanism 210 to cause the latch 215 to be moved from a locked to an unlocked position in the way that will be described further with reference to Figures 4a and 4b. Exerting a force on the switch plate 308 of the handle 302 in the Z-direction thus causes the switch device 309 to operate the electrical circuit 212 to electrically actuate the latch 215 of the latching mechanism 210.

As an exemplary alternative to the sensor assembly 306 comprising the switch device 309, the sensor assembly 306 could alternatively comprise a touch-responsive sensor device, for example, a capacitive touch sensor, responsive to the touch of a user's hand, and adapted to cooperate with the electrical controller 218 to detect a force exerted by a user on the handle acting in the Z-direction. In this alternative arrangement the touch-responsive sensor could be mounted to the inner surface of the lever 305 for contact directly by a user's hand and so the movable switch plate 308 may be omitted. Similarly, in this alternative construction a force exerted on the touch-responsive sensor in the Z-direction is countered by a corresponding force exerted by the lever 305 on the sensor.

The Bowden cable of the mechanical linkage 213 is shown more clearly in Figures 3a to 3c. As shown in the Figures, the Bowden cable comprises an inner cable 310 that is movable within a hollow outer cable housing 311. As is conventional, the inner cable 310 is substantially axially inextensible and the outer housing 311 is substantially axially incompressible. An end of the inner cable 310 is secured to the handle 302 close to the distal end of the handle. An end of the outer housing 311 is secured to the support plate 301 at a position above the point of attachment of the inner cable 310 to the handle 302. The Bowden cable is arranged such that in the rest position R of the handle the inner cable 310 is not tensioned by the handle, but such that movement of the handle 302 about the pivot pin 307 in the Y-direction to the operative position 0 tensions the inner cable 310 to exert a pulling force on the latch 215 of the latching mechanism 210 to cause the latch 215 to be moved from a locked to an unlocked position in the way that will be described further with reference to Figures 4a and 4b The handle assembly 211 further comprises a detent mechanism acting between the support plate 301 and the handle 302 functional to releasably retain the handle 302 in the rest position R. In the example the detent mechanism comprises a catch 312 formed by the support plate 301 and a correspondingly shaped recess 313 formed by the handle 302. The head of the catch 312 is oversized compared to the mouth of the recess 313 such that the catch is retained in the recess thereby preventing movement of the handle 302 in the Y-direction away from the rest position R and so avoiding tensioning of the inner cable 310 of the mechanical linkage 213.The head of the catch 312 is resiliently deformable and is configured to deform under an applied load exceeding a predetermined threshold acting in the Y-direction to permit withdrawal of the catch from the recess so releasing the handle 302 for movement. In the example the catch 312 and recess 313 pair are adapted such that a threshold force of at least approximately 50 Newtons acting in the Y-direction is required to be exerted between the recess and the catch before the handle 302 is released for movement towards the operative position. The detent mechanism thus functions to resist movement of the handle 302 reladve to the support plate 301 in the Y-direction away from the rest position R until a release force that is sufficient in magnitude to pull the catch 312 from the recess 313 is applied to the handle 302, whereupon the handle 302 is released for movement in the Y-direction to the operative position 0 thereby tensioning the inner cable 310 of the mechanical linkage 213.

Referring next to Figures 4a and 4b, the latching mechanism 210 comprises a housing 401 which houses the latch 215 and an electric actuator 402. As previously described, the latching mechanism 210 co-operates with a post of the striker 209 when the door is in the closed position to thereby latch the trailing edge 214 of the door 109 to the B-pillar 105A.

The housing 401 is generally cuhoid in shape and has a generally square opening 403 in the front thereof for exposing the latch 215 to the striker 209. The housing 401 is provided with fasteners 404 for securing the latching mechanism 210 to the trailing edge 214 of the door 109.

The latch 215 has the form of a hook and is rotatable within the housing 401 between the 'locked' position shown in Figure 5a in which the latch 215 hooks around the post of the striker 209 to prevent its withdrawal, and the 'unlocked' position shown in Figure 5h in which the latch 215 is rotated clear of the aperture such that the striker 209 may be withdrawn from the latching mechanism.

The actuator 402 is located within the housing 401 and comprises a rotary servomotor having a rotatable spindle 403 on which the latch 215 is mounted by an interference fit for rotation with the spindle and which thereby defines an axis of rotation of the latch 215. The actuator 402 is electrically coupled to the electrical control unit 218 of the electrical circuit 212 by wiring 217. The actuator 402 is thus controllable by the electrical control unit 218 to move the latch between the locked and unlocked positions on receipt from the electrical control unit 218 of an 'unlock' signal.

The latch 215 is further mechanically coupled to a second end of the inner cable 310 of the Bowden cable. The outer housing 311 of the Bowden cable is attached to the housing 401 of the latching mechanism 210. The latch 215 is thus further rotatable about the axis of rotation defined by the spindle 403 between the locked and unlocked positions by a pulling force exerted on the latch 215 by the Bowden cable.

Referring next particularly to Figures 5a and 5b, the well 208 of the door 109 is formed at a position above the aperture 207 by a well structure 501 located within the space 502 between the outer panel 203 and the inner panel 204 and fixed to the outer panel 201 The handle assembly 211 is located in the well 208. In this arrangement the handle assembly 211 is thus shielded from the exterior of the vehicle by the outer panel 203. Advantageously this may improve the aerodynamics of the vehicle as compared to a handle assembly located on the exterior surface of the vehicle. Furthermore, in this arrangement the handle is occluded from the normal view of a user standing outside the vehicle which may be considered more aesthetically pleasing. The handle assembly 211 however remains accessible to a person standing outside of the vehicle via the aperture 207 in the outer panel 203.

The outer side 304 of the support plate 301 of the handle assembly 211 is fixed to an inner side of the well structure 501 and the inner side 303 faces inwardly of the vehicle.

As previously described, movement of the handle 302 in the Z-direction relative to the support plate 301 is substantially prevented by the pivot pin 307. Consequently, a force applied by the user in the Z-direction on the switch plate 308 of the handle 302 will tend to depress the switch plate 308 against the switch device 309 and so operate the switch device 309 to transmit the 'unlock' signal to the electrical control unit 218 of the electric circuit 212. The electrical control unit 218 may then in turn energise the actuator 403 of the latching mechanism 210 to rotate the latch 215 between the locked and unlocked positions. Consequently, a force applied by a user on the switch plate 308 of the handle 302 in the Z-direction will cause the actuator 402 of the latching mechanism 210 to move the latch 215 to the unlocked position thereby releasing the door 109 for opening.

Further, because the handle 302 is arranged such that the switch plate 308 moves between the un-pressed and depressed positions in the Z-direction of the vehicle, that is 30 generally in the direction of opening of the door, a force maintained on the handle 302 in the first direction after operation of the switch device 309 and actuation of the latch 215 to the unlocked position will tend to cause the door 109 to open from its closed to its open position. Consequently in this arrangement unlocking of the latching mechanism 210 via the electrical circuit 212 and opening of the door may he performed by a user applying a force to the handle 302 in a continuous intuitive action.

Referring finally to Figures 6a and 6b, the handle 302 is arranged in the well 208 so as to be movable within the well 208 in the downward direction between the rest position R shown in Figure 6a and the operative position 0 shown in Figure 6b.

As previously described with reference to Figures 3a and 3b, the detent mechanism acts to retain the handle 302 in the rest position R in which the Bowden cable of the mechanical linkage is un-tensioned by the handle 302. A user applying a downward force to the handle 302, that is a force in the Y-direction, against the resistance of the detent mechanism may overcome the detent and move the handle 302 downwards in the well 209 through the aperture 207 in the outer panel 203. Movement of the handle 302 downwards relative to the support plate 301 pulls the inner cable 311 of the Bowden cable relative to the outer housing 312, which in turn causes the Bowden cable to actuate the latch 215 of the latching mechanism 210 to its unlocked position in which the latch 215 disengages the post of the striker, thus releasing the door 109 for opening by a user. Subsequent to the unlocking operation the user may then open the door 109 by applying to the handle 302 a second force acting in the outwards Z-direction.

Because the direction of movement of the handle 302 to actuate the latch 215 from its locked position to its unlocked position via the mechanical linkage 213 is different to the direction of opening of the door 109 from its closed to its open positions, the likelihood of an user who means to open the door inadvertently operating the mechanical linkage 213 so as to mechanically actuate the latch 215 is reduced. Specifically, it is expected that a user is unlikely to inadvertently apply to the handle 302 a downwards force sufficient to cause the handle 302 to move in the downward direction against the retaining force of the detent. Consequently, the likelihood of inadvertent actuation of the latch 215 via the mechanical linkage 213 is reduced.

Furthermore, because the handle 302 is arranged to move downwards within the well 208 to mechanically actuate the latch 215 via the linkage 213, rather than moving in the outward, Le in the Z-direction, of the door, the handle may permissibly be located in the well 208 despite its relatively small Z-direction dimension.

Claims (15)

1. Claims 1. A vehicle door latch assembly comprising: a handle; a latch having a locked position and an unlocked position; a mechanical linkage connecting the handle to the latch; an electric actuator connected to the latch; and a sensor for operating the actuator, wherein: the sensor is arranged to operate the actuator to move the latch from the locked to the unlocked position in reaction to a first force exerted on the handle in a first direction, the handle is movable in a second direction to act on the linkage to move the latch from the locked to the unlocked position in reaction to a second force exerted on the handle in the second direction; and the first direction is different to the second direction.
2. 2. A door latch assembly as claimed in claim 1, wherein the first direction and the second direction are nonparallel.
3. 3. A door latch assembly as claimed in claim 1 or claim 2, wherein the first direction and the second direction are orthogonal.
4. 4. A door latch assembly as claimed in any one of the preceding claims, adapted so that the second force required to move the latch from the locked position is greater than the first force required to move the latch from the locked position.
5. 5. A door latch assembly as claimed in any one of the preceding claims, wherein the handle is movable in the second direction between a rest position and an operative position, the latch assembly comprises a detent that retains the handle in the rest position, and the detent is adapted to release the handle for movement to the operative position only when the second force exerted on the handle exceeds a threshold force.
6. 6. A door latch assembly as claimed in claim 5. wherein the detent is adapted to release the handle for movement in the second direction only when the second force exceeds 50 N.
7. 7. A door latch assembly as claimed in any one of the preceding claims, wherein the sensor is mounted to the handle.
8. 8. A door latch assembly as claimed in any one of the preceding claims, wherein the sensor is a touch-responsive sensor.
9. 9. A door latch assembly as claimed in any one of the preceding claims, wherein the sensor is a capacitive sensor.
10. 10. A door latch assembly as claimed in any one of the preceding claims, further comprising a striker for releasable engagement by the latch.
11. 11. A vehicle comprising a door, a door frame and a door latch assembly according to any one of the preceding claims, wherein the door is movable relative to the door frame between a closed position and an open position, and the handle is mounted to the door.
12. 12. A vehicle as claimed in claim 11, wherein the first direction is in the direction of movement of the door from the closed position to the open position.
13. 13. A vehicle as claimed in claim 11 or claim 12, wherein the second direction is downwards.
14. 14. A vehicle as claimed in any one of claims 9 to 13, wherein the door comprises a door panel having an aperture and the handle is located behind the door panel at a position above the aperture.
15. 15. A vehicle claimed in any one of claims 9 to 14 when dependent on claim 10, wherein the latch is mounted to the door and the striker is mounted to the door frame.