EP1350913A2

EP1350913A2 - Latch assembly

Info

Publication number: EP1350913A2
Application number: EP03252045A
Authority: EP
Inventors: Veronique Mejean; Eric Colin; Mathias Barth
Original assignee: ArvinMeritor Light Vehicle Systems UK Ltd
Current assignee: ArvinMeritor Light Vehicle Systems UK Ltd
Priority date: 2002-04-02
Filing date: 2003-03-31
Publication date: 2003-10-08
Also published as: EP1350913A3; GB0207525D0

Abstract

A latch assembly including a retention module sub assembly, a release module sub assembly, and an inside release lever module sub assembly,

the retention module sub assembly including

a retention plate having a mouth to accept a striker,

a claw, for releasably retaining a striker,

and a pawl engageable with the claw for retaining the striker,

the release module sub assembly including a body, a pawl lifter in use being rotatably fast with the pawl and
capable of moving the pawl so as to release a striker

the inside release lever module sub assembly including a backplate,
an inside release lever operable, in use, by an inside release handle, to selectively move the pawl lifter.

Description

The present invention relates to latch assemblies and methods of assembling latch assemblies, in particular for use on vehicles such as cars.

Known latches are used to releasably secure vehicle doors in a closed position. They are mounted on the door and include a retention plate having a mouth which receives a striker, which striker is typically mounted on fixed structure of the vehicle. The retention plate includes an upstanding claw pivot pin and an upstanding pawl pivot pin, these pins being fixed non rotatably relative to the retention plate. Some known latches include a pawl which is rotatably fixed relative to a pawl pivot pin, the pawl pivot pin being rotatable relative to the retention plate.

Pivotally mounted on the claw pin is a rotatable claw having a claw mouth operable to receive the striker.

Pivotally mounted on the pawl pin is a pawl which operably engages a first safety abutment or a closed abutment of the claw in order to retain the claw, and hence the striker in a first safety or fully closed position. The pawl can be rotated out of engagement from the claw, thus allowing the claw to rotate to its open position and hence releasing the striker to allow the door to open.

The claw may be biased to its open position by a claw spring, the pawl may be biased to a position where it engages with the claw by a pawl spring.

Modern cars are provided with a passenger safety cell in order to protect the occupants of the vehicle in the event of a road traffic accident. The safety cell relies significantly on the doors remaining closed. Impact loads occurring during a road traffic accident can act to force (or burst) a door open and therefore the latch, and in particular the retention plate, claw, claw pin, pawl and pawl pin must be of sufficient strength to resist any such burst loads.

Latches on different vehicles, and in particular different latches on a particular vehicle will have different security/operating modes. Thus, a latch may be:-

a) openable by operation of an inside door handle,

b) openable by operation of an outside door handle,

c) lockable by operation of an inside sill button or the like,

d) lockable by operation of an outside key barrel or the like.

The state of a particular latch may include one or more of the following modes:-

a) unlocked

b) locked (i.e. operation of an outside door handle does not unlatch the latch but operation of an inside door handle does unlatch the latch)

c) superlocked (wherein any number of operations of an inside or an outside door handle, in any order, does not unlatch the latch)

d) child safety on (wherein operation of an inside door handle does not unlatch the latch, whereas operation of an outside door handle may or may not unlatch the latch, depending upon whether the door is locked or unlocked).

Furthermore a certain sequence of events can be used to perform desired functions:-

a) Thus, with a locked latched door, operation of an inside door handle may unlatch the latch and, at the same time, unlock the latch. Thus, upon subsequent closing of the door, the door is unlocked, and hence can then be opened by operation of the outside door handle. This is known as override unlocking and prevents vehicle keys being locked in the vehicle. This mode of operation is also useful to provide for opening of a locked door which is in child safety on mode, since, whilst operating of an inside door handle does not unlatch the latch, it nevertheless unlocks the latch and hence a subsequent operation of an outside door handle then enables the latch to be unlatched.

b) A sill button associated with certain types of latches, typically driver door latches, cannot be depressed when the door is open. This is also to prevent keys being locked in the vehicle. The only way of externally locking such a latch is to close the door and insert a key into a key barrel to lock the latch.

c) Certain other types of latch require an outside door handle to be lifted, when the door is in the open position, so as to enable the sill button to be pushed down so as to lock the door when the door is subsequently closed. Thus, the driver has to perform a specific sequence of events (i.e. Lift the outside door handle and then depress the sill button) in order to lock the door. This again is aimed at preventing keys being locked in the vehicle.

It can be seen that there are several modes of operation of known door locks and the way in which these functions are performed are typically carried out by mechanisms of the door latch (as opposed to mechanisms remote from the door latch). Ultimately, whichever mechanism is used, the door will only open when the pawl is moved out of engagement from the claw. Thus, locking, superlocking, and child safety modes all relate to providing a connection between a door handle and the pawl in order to move the pawl or breaking any such connection or blocking any such connection so as to prevent movement of the pawl.

Car door latches are typically mounted at the rear of a car door which car door is pivotally mounted at a front edge. Typically an inside door handle is mounted on the inside of the door, towards the front edge and therefore a connection needs to be provided connecting the inside door handle with the door latch. Depending on the location of the inside door handle and the nature of the connection with the latch (e.g. in some cases the nature of the connection is simply to provide the unlatching of the door, whereas in other cases the nature of the connection is to provide for unlocking and unlatching of the door), different latches require different types of connection and orientation of connection so as to be able to actuate the door latch.

To provide cost savings by virtue of economies of scale, a particular vehicle manufacturer will endeavour to commonise as far as possible, the latches fitted to the front and rear doors of a particular vehicle and also endeavour to commonise latches fitted to various models of his vehicle range.

From a latch manufacturers point of view, he will endeavour to commonise certain latch components as supplied to different vehicle manufacturers.

An object of the present invention is to provide for a cheaper latch assembly. Another object of the present invention is to provide a latch assembly having components which are susceptible of being fitted to different types of latch for use on

a) different doors of a particular vehicle, and/or

b) different vehicles of a particular vehicle manufacturer, and/or

c) different vehicles of different vehicle manufacturers.

Thus, according to the present invention there is provided a latch assembly including a retention module sub assembly, a release module sub assembly, and an inside release lever module sub assembly,
the retention module sub assembly including
a retention plate having a mouth to accept a striker,
a claw, for releasably retaining a striker,
and a pawl engageable with the claw for retaining the striker,
the release module sub assembly including a body, a pawl lifter in use being rotatably fast with the pawl and
capable of moving the pawl so as to release a striker
the inside release lever module sub assembly including a backplate,
an inside release lever operable, in use, by an inside release handle, to selectively move the pawl lifter.

Advantageously this provides a method of producing different specifications of latch from a limited number of sub assemblies.

Thus, the retention module sub assembly can be used on all latches destined for a particular vehicle manufacturer. Under some circumstances the retention module sub assembly can be used for all latches destined for more than one vehicle manufacturer.

Typically, three specifications of release module sub assembly can be produced, low line, medium line and high line. This allows for corresponding low line, medium line and high line latches to be manufactured.

Furthermore, where the retention module sub assembly is common to two vehicle manufacturers, but those manufacturers require different functioning of the latch (e.g. with and without manual override unlocking) then such latches can be produced by using differing release module sub assemblies (i.e. a manual override unlocking release module sub assembly and a non manual override unlocking release module sub assembly).

Different actuator module sub assemblies can be used depending upon the particular insulation requirement of the latch. Thus, different actuator module sub assemblies can be used for front and rear doors of the same vehicle. Also different actuator and module sub assemblies can be used for different ranges of a particular vehicle manufacturers vehicles. Also different actuator module sub assemblies can be used for different vehicle manufacturers.

The invention will now be described, by way of example only, with reference to the accompanying drawings in which:-

Figure 1 is an isometric view of an inside release lever module sub assembly of a first embodiment according to the present invention,

Figure 2 is an isometric view of a release module sub assembly of a first embodiment according to the present invention,

Figure 3 is an isometric view of a retention module sub assembly of a first embodiment according to the present invention, and

Figure 4 is an isometric view of a latch assembly of a first embodiment according to the present invention.

Figures 5 to 9 show the sequence of events required to assemble a second embodiment of a latch according to the present invention.

Figures 10 to 15 show specific components of latches according to the present invention.

Figures 16 and 17 show schematic representations of two bowden cables, of differing length, for use with latches according to the present invention.

Figure 18 shows a part view of figure 6, showing the lock link essentially in isolation.

With reference to the figures, similar components of the differing embodiments are labelled with the same reference number.

With reference to figure 4 there is shown a latch assembly 10.

With reference to figure 3 there is shown a retention module sub assembly 20 including a retention plate 22 including a mouth 24 for receiving a striker (not shown). Retention plate 22 includes claw pin 26 which projects from the retention plate and is rotatably secured therewith. A pawl pin 28 also projects from the retention plate and is also rotatably secure therewith. The retention plate includes mounting features, in this case in the form of three threaded holes 25. In use, screws are threaded into these holes to secure the latch assembly onto a door.

The retention plate has a first portion 23A which is generally planar and includes the threaded holes 25. The pawl and claw pins project from this first portion. The first portion is also cut away to form part of the mouth 24.

The retention plate 22 also includes a second major portion 23B which includes the cutaway to form part of mouth 24. Second portion 23B is positioned at substantially 90° relative to first portion 23a.

The retention 22 also includes tabs 35 which are bent from the first portion 23A, and are positioned at substantially 90° relative to the first portion 23A. Each tab 35 includes a lug 36 at an end remote from the first portion 23A.

Rotatably mounted on claw pin 26 is claw 27 which includes a mouth 27A for releasably retaining a striker. Claw 27 further includes a first safety abutment 27B and a closed abutment 27C.

Claw spring 30 (of figure 3) acts to bias claw 27 to an open position.

Mounted on pawl pin 28 is pawl 29 which includes a pawl tooth 32 for engagement with the first safety abutment 27B or the closed abutment 27C of the claw, so as to retain the claw in the first safety or closed position respectively. Retention module 20 of figure 3 further includes a pawl spring 34 which act to bias the pawl into engagement with the claw.

The claw, claw spring, pawl and pawl spring are fixed to the retention plate so as to form a stable sub assembly. The term stable sub assembly is here used to define a sub assembly wherein various components thereof cannot fall off the sub assembly thus transportation of such a sub assembly, for example between different factories, located in different countries, will not result in the sub assembly or components thereof falling off the sub assembly. In particular the retention module sub assembly 20 can be orientated in any direction, during transit, and gravity or vibration due to transport, will not cause any of the components to come off the sub assembly.

With reference to figure 2 there is shown a release module sub assembly 40. In this case the release module sub assembly 40 has been assembled onto the retention module sub assembly 20.

Release module sub assembly includes a body 41, a pawl lifter 43 (best seen in figures 10 and 11), an outside release lever 44, an outside release lever bias spring 44A (see especially figure 6), a lock link 45 (see especially figure 6 and 18), and a lock link lever 46.

Body 41 is made as an injection moulding from a plastics material. It forms part of a housing for the various components of the latch assembly. In particular it includes lock motor mounting 41A and superlock motor mounting 41B. It further includes a boss 41C (see figure 2 and only shown on figure 9 of the second embodiment) for receiving outside release lever spring 44A. Clips 41D are provided to receive part of a key mechanism. Cylindrical boss 41E (see especially figure 6) is provided to receive

bowden cable

75 or 76, depending on the particular installation.

Superlock motor 78 can be mounted in mounting 41B. Selective operation of superlock motors 78 will cause the latch assembly to be superlocked or non superlocked, as appropriate.

Pawl lifter 43 is best seen in figures 10 and 11 and includes a generally cylindrical body portion 43A having a central hole 43B which fits over pawl pin 28. Projecting from body portion 43A are two lugs 43C which engage in recesses 29A of pawl 29, thereby rotationally securing pawl lifter 43A with pawl 29.

Projecting generally tangentially from body portion 43A is an arm 43D. Depending upon the particular embodiment, a spring (not shown) can act on arm 43D to bias pawl lifter 43 and hence pawl 29 in an anticlockwise direction when viewing figure 10. This spring can be used in place of pawl spring 34 when required.

Pawl lifter 43 further includes an outside release abutment 43E and an inside release abutment 43F. The outside release abutment 43E is acted upon by outside release lever 44 as further described below, and the inside release abutment 43F is acted upon by the inside release lever 54, as will be further described below.

Outside release lever 44 (best seen in figures 12 and 13) includes a hole 44G which receives pawl pin 29. An abutment 44B is provided for use in conjunction with outside release abutment 43E. Lug 44C is engaged by spring 44A to bias the outside release lever 44 in an anticlockwise direction when viewing figure 12. End 44E of outside release lever 44 includes a fork 44F which is engaged by a bowden cable

inner cable

75A or 76A as will be described further below.

Lock link 45 includes abutment 45A which, when latches in an unlocked condition, sits between outside release abutment 43E of the pawl lifter and abutment 44B of the outside release lever. Thus movement of the outside release lever in a clockwise direction (when viewing figure 12) causes abutment 44B to engage the lock link abutment 45A causing it also to move in a clockwise direction thereby contacting and moving outside release abutment 43E of pawl lifter in a clockwise direction. The clockwise rotation of the pawl lifter in turn moves the pawl such that it disengages from the claw.

End 45B of the lock link engages with a pin 46A of lock link lever 46. Lock link lever 46 is pivoted at end 46B and can be moved in a anticlockwise direction when viewing figure 6 by lock motor 47 acting via a pinion 47A (see figure 7) on an array of teeth 46C of lock link lever 46. Thus, in use, lock motor 42 can be powered to move abutment 45A between abutment 44B and 43E, thereby unlocking the latch, or alternatively motor can be powered to withdraw abutment 45A from the space between abutments 44B and 43E, thereby locking the latch. It is also possible to lock the latch by using a key mechanism, which will be described further below.

The lock motor 42 may be configured so as to provide for unlocking of the latch upon operation of an inside door handle i.e. power override unlocking.

Release module sub assembly may further include a power unlatching actuator (not shown), operable to power unlatch the latch.

The release module sub assembly 40 is a stable sub assembly and is mounted onto the retention module sub assembly 20 in a direction of arrow A of figure 3 such that the claw and pawl pins pass through the release module sub assembly.

Figure 1 shows an actuator module sub assembly 50 (also known as an inside release lever module sub assembly, or backplate module sub assembly) having a backplate 52. Actuator module sub assembly 50 is a stable sub assembly. Backplate 52 includes holes 58, through which ends 26A and 28A of claw pin 26 and pawl pin 28 respectively can pass. The backplate further includes rectangular holes 52B through which lugs 36 can pass. In order to secure backplate 52, end 26a and 28a are deformed to form rivet heads. Lugs 36 are similarly deformed.

Backplate 52 includes a first portion 52C which lies generally in the same plane as first portion 23A. First portion 23C includes holes 58 and rectangular holes 52B.

Bent at substantially 90° to the first portion 52C is a second portion 52D. Second portion 52D lies substantially parallel to second portion 23B. Second portion 52D includes a hole through which a pin 52E is passed to secure a two part inside release lever 54.

The inside release lever 54 comprises a first part 54A and a second part 54B (best seen in figures 14 and 15). First part 54A includes a hole 54C for receiving pin 52E. A fork 54D is provided for connection with a bowden cable inner cable. An L-shaped recess 54E is provided.

Second part 54B includes a hole 54F which receives pin 52E. An L-shaped recess 54G is provided. A pawl lifter abutment 54H is provided. Arm 54I includes an override abutment 54J. When assembled, the first and

second parts

54A and 54B are both rotatably mounted on pin 52E via hole 54C and 54F. As such, regions B and C of the L-shaped recesses 54e and 54G are aligned. In order to provide for child safety or superlocking, a pin (not shown) can be positioned at region B. When so positioned, anticlockwise movement of first part 54a does not cause movement of second part 54b since the pin moves relative to the first and second parts to region D.

When child safety is off, or when the lock is not superlocked, the pin sits in region C. Thus, anticlockwise movement of first part 54A causes anticlockwise movement of second part 54B since both parts are coupled together by the pin. Anticlockwise movement of second part 54B causes pawl lifter abutment 54H to engage and move internal release abutment 43F of pawl lifter 43. This causes pawl lifter 43 to rotate in a clockwise direction when viewing figure 10, thereby disengaging the pawl from the claw and allowing the latch to open.

In a further embodiment, the second part 54 of the backplate 52 can include an extension 52F having a pin 52G secured thereto. Pivotally mounted on pin 52g is override unlock lever 60. End 60A of override unlock lever 60 is engageable by override abutment 54J. End 60B is engageable with a further embodiment of lock link lever 46. Anticlockwise movement of second part 54b causes anticlockwise rotation of override unlock lever 60 about pivot 52G. This in turn causes end 60B to engage with and move the further embodiment of the lock link lever 46 thereby unlocking the door in the event that the door was locked.

Figures 5 to 9 show the assembly sequence of a second embodiment of a latch.

Figure 5 shows a retention plate sub assembly.

Figure 6 shows the release module sub assembly having been assembled onto the retention plate.

Figure 7 shows the back plate having been assembled.

Figure 8 shows a key mechanism having been assembled. In particular rod 65 can be moved longitudinally by operation of a key. Drive to rod 65 comes via a key barrel mounted on the door which is connected to components 64. End 65A of rod 60 is engaged in a slot 460 (see figure 6) of the lock link lever 46. Longitudinal movement of rod 65 to the left when viewing figure 8 causes the lock link lever to move such that the lock link abutment 45A is withdrawn from the gap between abutment 44B and 43E, thereby locking the latch. Longitudinal movement of rod 65 towards the right when viewing figure 8 causes end 65A to move to the other end of the slot 46D in the lock link lever and then to move the lock link lever such that abutment 45a moves between abutments 44B and 43E, thereby unlocking the latch.

A cover 68 is then placed over the latch and secured. Outside release cable then can be inserted through cylindrical boss 41E such that the inside cable engages with fork 44F, thereby to couple the cable inner with the outside release lever 44. A similar operation can connect a further cable via boss 70 to fork 54D. It should be appreciated that different sub assemblies can be provided, depending upon the particular requirement of the latch. For example:-

The retention module subassembly can include a pawl bias spring (as in figure 3), or alternatively this spring can be included on the release module sub assembly.

The release module subassembly can include a claw bias spring (as in figure 6), or alternatively the pawl bias spring can be included on the retention module sub assembly (as in figure 3).

The release module sub assembly can include lock motor 42 or this motor need not be fitted. When this motor is not fitted, nevertheless the lock link lever 46 can be fitted and thus the teeth 46B become redundant. The superlock motor may or may not be fitted to superlock motor mounting 41B. Different bodies can be provided and they may or may not include motor mountings 41A, superlock motor mountings 41B, or clips 41D. Where

cylindrical boss

41E or 70 is provided, this may be orientated in different directions on different bodies to provide for different cable routings. The backplate subassembly can include a two piece inside release lever (as in figure 7). Alternatively the inside release lever can be formed as a single piece. Under such circumstances, it is not possible to provide child safety or superlocking of the latch. Thus, such a latch would be used on a two door car, typically destined for United States of America where superlocking is not required. The inside release lever (as a two part lever or a one part lever) may or may not include an override abutment 54J. The backplate may or may not include an override unlocking lever 60. In particular, it will be appreciated that a latch may not include an override unlock lever 60, but may nevertheless include a redundant extension 52F and a redundant override abutment 54J on the inside release lever.

By providing various features, it is possible to utilise these features on those latches that require the feature, but nevertheless the features can become redundant features for those latches that do not require the feature. In this way it is possible to minimise the part count for the latches.

It can be seen that it is possible to provide differing latch assemblies. A first latch assembly comprising retention module sub assembly 20, one form of release module sub assembly 40 and the inside release lever module sub assembly 50. A further form of latch assembly could comprise a retention module sub assembly 20, a different form of release module sub assembly 40 and the inside release lever module sub assembly 50.

Alternatively, different latch assemblies could be provided by using common retention module sub assemblies and release module sub assemblies, but differing forms of inside release lever module sub assemblies.

In particular, the specification of a low line latch assembly would be for manual release only i.e. no power release. The low line specification might further include a mechanical override unlocking mechanism (especially lever 60) i.e. no power override unlocking and it might also include only a mechanical connection to an outside key barrel (especially rod 65), i.e. no power locking feature.

A medium level latch assembly might again include manual release i.e. no power release. If override unlocking is provided, then this might be by virtue of a power actuator causing unlocking (rather than a mechanical linkage). Furthermore locking/unlocking would be by virtue of a power actuator.

Typically a high level latch assembly would include power release, power override unlocking and power locking/unlocking.

Claims

A latch assembly including a retention module sub assembly, a release module sub assembly, and an inside release lever module sub assembly,
the retention module sub assembly including
a retention plate having a mouth to accept a striker,
a claw, for releasably retaining a striker,
and a pawl engageable with the claw for retaining the striker,
the release module sub assembly including a body, a pawl lifter in use being rotatably fast with the pawl and
capable of moving the pawl so as to release a striker
the inside release lever module sub assembly including a backplate,
an inside release lever operable, in use, by an inside release handle, to selectively move the pawl lifter.
A latch assembly as defined in claim 1 in which the release module sub assembly is substantially sandwiched between the retention module sub assembly and the inside release lever module sub assembly.
A latch assembly as defined in claim 1 or 2 in which the claw is pivotally mounted on a claw pin non rotatably fixed to the retention plate and the pawl is pivotally mounted on a pawl pin non rotatably fixed to the retention plate.
A latch assembly as defined in claim 3 in which the release module sub assembly is positioned over the claw and pawl pins.
A latch assembly as defined in claim 3 or 4 in which the inside release lever module sub assembly is positioned over the claw and pawl pins.
A latch assembly as defined in claim 5 in which the claw and pawl pins have fixing means, such as deformable ends, so as to secure the inside release lever module sub assembly to the retention module sub assembly.
A latch assembly as defined in any preceding claim in which the retention module sub assembly or the release module sub assembly includes a claw bias means, operable to bias the claw to an open position.
A latch assembly as defined in any preceding claim in which the retention module sub assembly or the release module sub assembly includes a pawl bias means operable to bias the pawl to an engaged position.
A latch assembly as defined in any preceding claim in which the release module sub assembly includes an outside release lever operable, in use, by an outside release handle to selectively move the pawl lifter.
A latch assembly as defined in any preceding claim in which the release module includes a lock link operable to lock and unlock the door upon operation of an outside key barrel or the like or a lock motor.
A latch assembly as defined in any preceding claim in which the release module sub assembly includes a lock motor operable to lock and unlock the door.
A latch assembly as defined in claim 11 in which the lock motor is automatically operated upon actuation of the inside release lever to provide for power override unlocking.
A latch assembly as defined in any preceding claim in which the release module includes a superlock motor operable, in use, to superlock and unsuperlock the latch assembly.
A latch assembly as defined in any preceding claim in which the inside release lever module sub assembly includes an over ride lever that provides for mechanical override unlocking upon operation of the inside release lever.
A latch assembly as defined in any preceding claim in which the inside release lever is a two piece lever thereby capable of providing a superlock function and/or a child safety function.
A latch assembly as defined in any preceding claim in which at least one, preferably two, preferably three of the retention module, release module, and actuator module sub assemblies is/are stable sub assemblies.
A method of assembling a latch assembly including the steps of:-

a. providing a first retention module sub assembly including a retention plate having a mouth to accept a striker, a claw for releasably retaining a striker, and a pawl engageable with the claw for retaining the striker,

b. providing a first release module sub assembly including a body, a pawl lifter, in use being rotatably fast with the pawl and capable of moving the pawl so as to release the striker,

c. providing a first inside release lever module sub assembly including a backplate, an inside release lever operable, in use, by an inside release handle, to selectively move the pawl lifter,

d. assembling the sub assemblies to provide the latch assembly
A method as defined in claim 17 of assembling a latch assembly further including the steps of providing at least one of:-

i. a further retention module sub assembly, differing from the retention module sub assembly of claim 17,

ii. a further release module sub assembly, differing from the release module sub assembly of claim 17,

iii. a further inside release lever module sub assembly, differing from the actuator module sub assembly of claim 17,

and selecting one of the first or further retention module sub assemblies
selecting one of the first or further release module sub assemblies
selecting one of the first or further inside release lever module sub assemblies and assembling said selected sub assemblies to provide the latch assembly.