[0001] The present invention relates to latch mechanisms for doors of vehicles. The invention
further relates to vehicles including at least 2 doors, each door incorporating a
latch mechanism.
[0002] It is known to provide latch mechanisms on doors of vehicles to allow opening and
closing of the door. Such latch mechanisms have various modes of operation e.g.
a) Lock mode, wherein operation of an outside door handle does not open the latch
mechanism
(b) Superlocked mode, when in operation of an outside or an inside release lever does
not operate the latch mechanism.
(c) Child safety mode, wherein operation of an inside release lever does not open
the latch mechanism, whether or not the latch mechanism is locked, and
(d) Release mode, wherein the latch mechanism is released via means other than operation
of the inside or outside release levers.
[0003] Each mode has alternate states eg locked/unlocked, superlocked/notsuperlocked, child
safety on/off and release/not released.
[0004] Typically each mode requires an individual mechanism to effect the alternative states,
with operation of each mechanism being affected either manually or with an individual
power actuator.
[0005] In the case of a latch mechanism operated entirely by power actuators such as DC
motors, it is also necessary to be able to open a locked door which has the child
safety feature on in an emergency situation when actuation of the power actuators
is not possible, such as when the keys to the vehicle are not available.
[0006] According to an aspect of the present invention there is provided a vehicle including
a first and second door, each door including respective first and second latch mechanisms,
the first and second latch mechanisms being substantially the same, and being operable
by respective first and second power actuators to give respective first and second
sets of operating modes, each mode having alternate states, control of the power actuators
being different to provide for different first and second sets of operating modes.
[0007] The invention will now be described by way of example only with reference to the
accompanying drawings in which:
FIGURE 1 is a latch mechanism according to the present invention in a super-locked
condition;
FIGURE 1a is an enlarged view of part of Figure 1;
FIGURE 1b is a schematic view in the direction of arrow A of Figure 1;
FIGURE 2 is the latch mechanism of Figure 1 in a locked position with child safety
on;
FIGURE 3 is the latch mechanism of Figure 1 in an unlocked condition with the child
safety on;
FIGURE 4 is the latch mechanism of Figure 1 in a locked condition with the child safety
off;
FIGURE 5 is the latch mechanism of Figure 1 in an unlocked position with the child
safety off; and
FIGURE 6 is a latch mechanism of Figure 1 in a release position.
[0008] With reference to Figures 1 to 6 there is a latch mechanism 10 including a body 11
which supports various components of the latch mechanism 10 as indicated below.
[0009] Latch mechanism 10 further includes a claw 12 pivotally mounted about axis 13 on
the body 11. Claw 12 acts to secure an associated door (not shown) in a closed position
via a striker pin 14 attached to the door aperture. Rotation of the claw 12 in an
anticlockwise direction about axis 13 when viewing Figure 1 allows release of the
striker pin 14, thus enabling opening of the associated door.
[0010] The claw 12 is held in a closed position by a pawl 15, only part of which is shown
in dotted profile in Figure 1 for clarity. Pawl 15 is pivotally mounted on body 11
and can rotate about axis 16. Claw 12 can be held in a first safety position (not
shown) when pawl 15 engages first safety abutment 17.
[0011] Pawl lifter 20 is generally flat and lies in a plane parallel to pawl 15, to which
it is rotationally secured. When viewing Figure 1 pawl 15 is obscured by pawl lifter
20. Clearly, pawl lifter 20 also rotates about axis 16.
[0012] Inside lock link 21 and outside lock link 22 are mounted for movement with the pawl,
in this case they are each individually pivoted about respective axes 21a and 22a
on pawl lifter 20. In this case inside lock link 21 and outside lock link 22 are identical
and each have respective cam followers 21b and 22b and release abutments 21c and 22c.
Inside lock link 21 and outside lock link 22 are each biased in a clockwise direction
when viewing Figure 1 such that the respective cam followers 21b and 22b contact cam
30.
[0013] Cam 30 is capable of rotating independently from pawl lifter 20 about axis 16. Cam
30 has three lobes 31, 32, and 33 and two levers 34 and 35 shown diagrammatically
for clarity. Lobes 31, 32, 33 and levers 34 and 35 are all rotationally fast with
cam 30.
[0014] Preferably cam 30 can at least be rotated to the various positions as described below
by a power actuator (not shown) such as a DC motor or preferably a stepper motor.
[0015] Outside release lever 40 is pivotally mounted about axis 41. Inside release lever
43 (shown diagrammatically in Figure 1b) is pivotally mounted about axis 44.
[0016] Operation of a door latch mechanism is as follows.
[0017] Figure 1 shows the door latch mechanism in a super lock condition, that is to say
operation of the outside release lever 40 or inside release lever 43 does not allow
unlatching of the mechanism. In particular it can be seen that if outside release
lever 40 were to be operated by being rotated in a clockwise direction about axis
41, abutment 42 would pass release abutment 22c of outside lock link without contact
(note that outside release lever 40 is in the same plane as outside lock link 22).
Similarly inside release lever 43 when operated by being rotated in an anticlockwise
direction about axis 44 when viewing Figure 1b would cause abutment 45 to pass release
abutment 21c of inside lock link 21 (see especially Figure 1).
[0018] Figure 2 shows the door latch mechanism 10 in a locked position with the child safety
feature on. It will be noted that cam 30 has been rotated 30 degrees in an anticlockwise
direction when compared to Figure 1. However, the inside lock link 21 and outside
lock link 22 are in the same position when compared with Figure 1 since neither of
the cam followers 21b or 22b have, at this stage, ridden up any of the lobes 31, 32
or 33 or the cam 30. However, lever 34 has been rotated to a position whereby operation
of the inside release lever 43 in an anticlockwise direction when viewing Figure 1b
would cause abutment 46 to contact lever 34 and rotate cam 30 to the position shown
in Figure 3. Note this initial operation of inside release lever 43 does not unlatch
the mechanism but only operates to unlock the door (see below). This method of being
able to override and open a locked door which has the child safety on is especially
important in an emergency situation whereby a passer-by can effect access to the inside
door handle (eg by breaking the door window glass), operate the inside door handle
to unlock the door, then operate the outside door handle to open the door and then
remove the child from the car.
[0019] Figure 3 shows the door latch mechanism 10 in an unlocked condition with the child
safety feature on. In this case the cam 30 has been rotated sufficiently (either by
operating the inside release lever when the cam was in the position shown in Figure
2 or by independent rotation of the cam directly eg by a power actuator) such that
cam follower 22b has ridden up cam lobe 32 resulting in anticlockwise rotation of
outside lock link 22. Thus when outside release lever 40 is operated, abutment 42
contact release abutment 22c causing the pawl lifter 20 as a whole to rotate anticlockwise
when viewing Figure 3 and releasing the pawl 15 and allowing the claw 12 to open.
Stop 22d limits the anticlockwise rotation of outside lock link 22. Upon release of
the outside release lever 40 the pawl lifter 20 is biased back to the position as
shown in Figure 3 by a spring (not shown). It should also be noted that the inside
lock link 21 is in the same position as that shown in Figure 1, thus operation of
the inside release lever 43 does not allow opening of the door.
[0020] Figure 4 shows the door latch mechanism 10 in a locked condition with the child safety
feature off. It should be noted that the cam 30 has been rotated 90 degrees in an
anticlockwise direction when compared with Figure 1. This results in cam follower
22b being situated between lobes 32 and 33 thus ensuring that operation of outside
release lever 40 does not release the latch mechanism. Furthermore, the rotation of
the cam 30 has caused cam follower 21b to ride up cam lobe 31 causing inside lock
link 21 to rotate anticlockwise about axis 21a. Thus abutment 21c of inside lock link
21 is contacted by abutment 45 of inside release lever 43 when it is operated. This
causes anticlockwise rotation of the pawl lifter 20 about axis 16 resulting in unlatching
of the door mechanism and allowing the door to be subsequently opened. Stop 21d limits
the anticlockwise rotation of inside lock link 21. It should be noted that the operation
of the inside release lever 43 also causes abutment 46 to contact lever 35 causing
rotation of cam 30 to the position shown in Figure 5. This prevents a vehicle occupant
inadvertently locking himself out of the vehicle since opening of the door from the
inside automatically unlocks the door, allowing subsequent opening from the outside.
[0021] Figure 5 shows the door latch mechanism 10 in an unlocked position with the child
safety feature off. It can be seen that the cam has been rotated (either by operating
the inside release lever when the cam was in the position shown in Figure 4 or by
independent rotation of the cam directly eg by a power actuator) such that abutment
22b now rests on lobe 33 allowing operation of the outside release lever 40 to unlatch
the latch mechanism as described above. Furthermore abutment 21b remains in contact
with lobe 31 thus ensuring that operation of the inside release lever also unlatches
the door mechanism.
[0022] Figure 6 shows the door latch mechanism 10 in a released position. This is achieved
by rotation of cam 30 in an anticlockwise direction which allows contact between corresponding
lost motion abutments (not shown) on the pawl lifter 20 and cam 30. Such lost motion
abutments allow the cam 30 to rotate the pawl lifter 20 to release the door latch
mechanism independently of the operation of the outside release lever 40 or the inside
release lever 43.
[0023] Note that only a single cam is required to effect the various modes of operation.
[0024] In further embodiments the inside and outside lock links can be mounted directly
on the pawl.
1. A vehicle including a first and second door, each door including respective first
and second latch mechanisms (10), the first and second latch mechanisms being substantially
the same, and being operable by respective first and second power actuators to give
respective first and second sets of operating modes each mode having alternate states,
control of the power actuators being different to provide for different first and
second sets of operating modes.
2. A vehicle as defined in claim 1 wherein the first and second sets of operating modes
for each latch include at least two of a lock mode, a super lock mode, a child safety
mode and a release mode, changing of the latch mechanism between alternate states
of each of the at least two modes of the set being effected by the respective single
power actuators.
3. A latch mechanism as defined in claim 2 in which the set includes the lock mode and
the super lock mode and at least one of the child safety mode and release mode.
4. A latch mechanism as defined in claim 2 or 3 in which the set includes at least one
of the lock mode and super lock mode and both of the child safety mode and the release
mode.