Note: Descriptions are shown in the official language in which they were submitted.
CA 02288225 1999-10-28
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CONTROL ASSEMBLY FOR LIFT GATE OR
SLIDING A.t~ID CARGO DOORS
Field of Invention
This invention relates to closure members for vehicles which close a
compartment
such as a tailgate, a cargo door, or a sliding door or the like. The door is
typically moved,
for example pivoted or slid from a closed position to an open position. In
order to effect
this movement, a handle must be operated through a control assembly to release
the latch
mechanisms allowing the closure to be moved to the open position. This present
invention
finds particular application therefore in providing such a control assembly
which has
simplified the structures heretofore known reducing the number of parts
thereof and
increasing the reliability thereof while reducing the overall power
consumption required in
a preferably power actuated control assembly.
Background of Invention
Within the prior art there exists a number of structures for releasing a
closure such
as a tailgate. For example, United States Patent No. 5,531,498, as one
example, refers to a
power lift-type tailgate and includes a control assembly which is cable driven
once the
latches are released. The drive includes a motor driving a cable reel to lift
the tailgate
assembly.
Other designs are also known, which designs have been installed on the lift
gates of
certain production vehicles. These designs include an actuator which converts
linear motion
to a rotary motion for the locking lever, and then through the two-position
floating pin to a
further linear motion of the floating pin to a rotary motion for the output
lever to a further
linear motion far the cable release. A significant amount of friction
therefore is developed,
and hence friction loss,is experienced as a result of utilizing such a system.
Incorporated
with the locking lever is a two-position over center toggle spring which
allows the two
positions attained by the floating pin. The locking lever has an emergency
manual override
tab which may be accessed should the actuator fail. Therefore, when the input
lever is
operated by a handle connected to the control via a rod or a cable, the input
arm of the input
lever will engage the floating pin and therefore allow release of the latches.
Should the
floating pin however be moved via the operation of the locking lever to the
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position, then the input arm of the input lever will not be able to access the
floating pin, and
hence the output lever will not operate in spite of the fact that the input
lever will operate.
Such a control assembly therefore includes a first pivot connected to the
locking lever, a
second pivot connected with the floating pin, a third pivot about which the
locking lever
pivots, and a fourth pivot about which the input lever and the output lever
pivot. Within the
actuator itself, it is estimated that the electrical requirements would be
approximately 10 .
watts normally, and peak at approximately 50 watts or more, with up to 5 amps
being
drawn by the motor.
Clearly therefore, the problems can be seen in providing such a device in that
a
significant amount of the power utilized by the actuator goes into friction
losses when
transferring the power from the actuator to the actual cables. Secondly, the
reliability of the
product must be questioned in that many of the parts, for example such as the
tab from the
locking lever which accesses the opening of the linear actuator plunger,
undergoes a
dynamic load over each cycle and may tend to fail in time. Secondly, the pivot
for the
locking lever may tend to bind in time, or the floating pin may also bind
within the slot
between its two positions.
Summary of the Invention
The disadvantages of the prior art may be overcome by providing a latch
control
assembly having a simple mechanism for locking and unlocking a lift gate or
door and for
effecting unlatching thereof.
According to one aspect of the invention, there is provided a control assembly
for
releasing a latch. The control assembly has a base plate for mounting
components of the
control assembly. A pivotally mounted input lever is movable between a ready
position and
a release position. The input lever connects to a release handle. A pivotally
mounted
output lever connects to a latch and transmits a releasing force. A pivotally
mounted
locking lever is rotatable between a locked position and an unlocked position.
A link
slidably engages the output lever and pivotally engages the locking lever.
When the
locking lever moves between the locked and unlocked positions, the link
responsively
decouples and couples the input lever and the output lever to allow
independent and
CA 02288225 1999-10-28
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dependent rotation thereof, respectively, selectively transferring the
releasing Force from the
release handle to the latch.
Description of the Drawings
In drawings which illustrate an embodiment of the invention,
Figure 1 is a perspective view of lift gate incorporating the control assembly
of the present invention;
Figure 2 is an exploded view of the control assembly of the present invention:
and
Figure 3 is a perspective view of the control assembly of Figure 2;
Description of the Invention
Referring rlow to Figure 1, there is illustrated a tailgate assembly or door
assembly
12, normally pivotally mounted, which allows the door 12 to swing upwardly in
the
conventional motion of a tailgate. Two latches, 14 and 16 are conveniently
located
proximate the sides of the tailgate 12 which will engage keepers or strikers
when the
tailgate 12 is closed. The latches 14, 16 are oriented in such a way that the
fish mouths will
each engage with the respective strikers as is well known in the art. The
latches 14, 16 are
conventional and include pawl release levers to which are connected the Bowden
cables 18,
20 for each latch. The Bowden cables 18, 20 are conveniently run through clips
in openings
in the body panels which allow motion of the cable and yet securement of the
cable in
relation to the panel. The Bowden cables 18, 20 operatively connect to the
control
assembly 10 of the present invention. Release handle 22 is operatively
connected via a
cable or rod 24 to the input lever of control assembly 10. Release handle 22
is pivotally
mounted to the tailgate 12 in a manner conventional in the art. Actuation of
the release
handle 22 effects the release of the latches 14, 18 when the control assembly
10 is in the
operative or unlocked position which will be described hereinafter.
Referring now to Figure 2, there is illustrated the control assembly 10 which
includes a mounting or base plate 26, an input lever 28, an output lever 30, a
locking block
32, a locking lever 34 and an actuator 36. ~ _
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CA 02288225 1999-10-28
Base plate'_6 is preferably a stamped metal formed with various features
including
mounting holes. Bowden cable attachment tabs 38, 40, an arcuate guide slot 42,
and a
control window 44. Tabs 38, 40 extend generally perpendicular from base plate
26. Tabs 38
and 40 have cutouts for receiving the outer cable shell or sheath of Bowden
cables 18, 20.
Base plate 26 has an embossed area 46 having a bore 48 and an embossed area 50
having a
bore 52. Base plate 26 is otherwise configured for mounting the components of
the control
assembly 10 onto the base plate 26 and for matching the footprint for mounting
the control
assembly 10 onto the frame of the lift gate 12.
Input Lever 28 is preferably a stamped metal and formed to be pivotally
mounted
onto base plate 26. Input lever 28 has two arms 54, 56 extending from opposite
sides of
pivot 58. Arm 54 has tabs 60, 62 extending in opposite directions. Tab 62
extends towards
the base plate ?6 and extends through control window 44. Control window 44
limits the
pivotal travel of the input lever 28 between a ready position and a release
position. Arm 56
has a tab 64 having an aperture for receiving spring 66. Spring 66 extends
between tab 40
and tab 64 to bias the input lever 28 to the ready position.
Output lever 30 is preferably a stamped metal and formed to be pivotally
mounted
onto base plate 26 coaxially with input lever 28. Output lever 30 is mounted
on pivot pin
68 which pivotally mounts input lever 28 through bore 48 on base plate 26.
Output lever 30
has three arms 70, 72 and 74. Arms 70, 72, 74 extend radially from a central
pivot 76
through which pivot pin 68 extends. Arms 70, 72 are preferably diametrically
opposed.
The distal ends of arms 70, 72 each has a bore for receiving clips 78, 80 in a
snap fit. Clips
78 and 80 are connected to the ends of cables 18, 20, respectively. Pivotal
movement of
output lever 30 will simultaneously extend and retract each of cables 18, 20
for release of
latches 14, 16. Arm 72 has a tab 82 at the distal end, which tab extends
through guide slot
42 on base plate 26. Guide slot 42 limits pivotal travel of the output lever
30. Arm 74 has
a radially extending slot 84 and a cooperating axially extending flange 86.
Spring 87
extends between arm 74 and the base plate 26 to bias the output lever 30 to a
position,
whein the cables 18, 20 will be at an unextended length or retracted position.
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The locking Lever 34 is preferably a stamped metal component and formed to be
drivingly mounted on output shaft 88 of actuator 36. Locking lever has two
arms 90, 92
extending from a central core 94. Core 94 has an aperture complementary to the
shape of
output shaft 88 For a driving engagement therewith. A screw 9~ attaches the
locking lever
~ 34 to the output shaft 88. Arm 90 has a tab 96 at the distal end. Arm 92 has
a keyway
aperture 97 for pivotally connecting with link 98 of locking block 32.
Connecting link 98
has, at one end, pin 100 having locking tabs 102 and locking block 32 at the
opposite end.
Locking block 32 is pivotally connected to and slightly spaced from the
connecting link 98.
The locking tabs 102 can be inserted into keyway aperture 97 to pivotally
connect the
connecting link 98 to the locking lever 34. The locking block 32 engages the
output lever
30. Specifically the mounting pin of the locking block 32 will be inserted
through slot S-1 of
output lever 30. Locking block 32 will slide against flange 86. Rotation of
locking lever
34 will cause the locking block 32 to slide in the slot 84 between an
operative or unlocked
position wherein the locking block 32 will extend beriveen the flange 86 and
the tab 60 of
1 ~ input lever 28 and an inoperative or locked position wherein the locking
block 32 does not
engage tab 60 of input lever 28. In the embodiment illustrated, the operative
position is
radially outward and the inoperative or locked position is radially inward
along slot S-1.
Actuator 36 is conventional in design. In one embodiment of the invention, a
motor
~0 drives output shaft 88 through a series of gears (not illustrated) to
rotate locking lever 34
between a locked position and an unlocked position.
Referring now to Figure 3, the locking block 32 moves linearly along the slot
84.
When the locking block 32 is in the operative or unlocked position, movement
of the input
25 lever 28 will translate to the output lever 30 through the locking block
32, so that the input
lever 28 is coupled to the output lever 30 to rotate dependently. However,
when the Locking
block 32 travels radially inwardly to the disengaged or locked position, the
operative
connection between the input lever 28 and the output lever 30 is removed.
Input lever 28 is
uncoupled from the output lever 30 to rotate independently. Should the handle
22 be
30 utilized and the input lever 28 rotated, the input lever 28 will merely
freely move on its
pivot without moving any of the other components of the control assembly 10.
Further, the
locking lever 34 has an emergency manual override tab 96 which may be accessed
should
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the actuator 36 fail, or alternatively in another embodiment, when the
actuator is not
present, be in communication with a manually operable user accessible device
such as a
knob or the like or alternatively in communication with a child proofing
lever.
In operation therefore, the actuator 26 or user accessible operator would be
operated
or powered via a push button, knob, a remote or the like causing the rotation
of the locking
lever 34 about its pivot, and therefore cause the linear motion of the locking
block 32
relative to arm 74 of the output lever 30, moving the locking block 32 in and
out of
operative interconnection between the input lever 28 and the output lever 30
to couple and
uncouple the input lever 28 and the output lever 30. Therefore, when the
locking block 32
is in the operative or unlocked position, the actuating tab 60 of the input
lever 28 will
engage the locking block 32 adjacent thereto which in turn will transmit any
force
transmitted through the input lever 28 to the flange $6 of the output lever 30
causing the
output lever 30 to rotate upon its pivot to allow for the release of the
latches 14, 16 as the
cables 18, 20 are retracted responsive to the output lever 30 rotation.
However, when the
locking block 32 is translated to the disengaged or locked position, whereat
the tab 60 can
no longer engage the locking block 32, regardless of movement of the handle 22
and input
lever 28, the latches 14,16 cannot release.
The invention has been described in an illustrative manner with respect to the
preferred embodiments thereof, and it is understood and implied that the
terminology that
has been used is intended to be for descriptive purposes only and not for the
interpretation
in limiting the invention. As many changes can be made to the preferred
embodiments of
the invention without departing from the scope thereof; it is intended that
all matter
contained herein be considered illustrative of the invention and not in a
limiting sense.
