U.S. patent application number 11/923712 was filed with the patent office on 2009-04-30 for vehicle endgate counterbalance.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS, INC.. Invention is credited to Gary W. Krajenke.
Application Number | 20090108613 11/923712 |
Document ID | / |
Family ID | 40581893 |
Filed Date | 2009-04-30 |
United States Patent
Application |
20090108613 |
Kind Code |
A1 |
Krajenke; Gary W. |
April 30, 2009 |
VEHICLE ENDGATE COUNTERBALANCE
Abstract
A vehicle having an endgate counter balance for use with an
endgate of the vehicle, and a method of operating, is disclosed.
The endgate counterbalance may include a hinge arm extending from
the hinge, an energy storage device and a crank mechanism connected
between the hinge arm and the energy storage device. The endgate
counterbalance is configured to create a cross-over position for
the endgate between closed and fully open where the endgate
counterbalance does not exert a rotational bias on the endgate.
Inventors: |
Krajenke; Gary W.; (Warren,
MI) |
Correspondence
Address: |
GENERAL MOTORS CORPORATION;LEGAL STAFF
MAIL CODE 482-C23-B21, P O BOX 300
DETROIT
MI
48265-3000
US
|
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS,
INC.
DETROIT
MI
|
Family ID: |
40581893 |
Appl. No.: |
11/923712 |
Filed: |
October 25, 2007 |
Current U.S.
Class: |
296/57.1 |
Current CPC
Class: |
B62D 33/0273 20130101;
E05Y 2900/516 20130101; E05Y 2900/546 20130101; E05Y 2201/626
20130101; E05F 1/1292 20130101; E05Y 2900/544 20130101; E05F 1/1238
20130101 |
Class at
Publication: |
296/57.1 |
International
Class: |
B62D 33/03 20060101
B62D033/03 |
Claims
1. An endgate counter balance for use with an endgate of a vehicle
having a hinge about which the endgate pivots between a closed
position and a fully open position, the endgate counterbalance
comprising: a hinge arm extending from the hinge and pivotally
fixed relative to the endgate; an energy storage device having a
first end and a second end configured to mount to vehicle
structure, the energy storage device configured to store and
dissipate potential energy as the first end is moved relative to
the second end; and a crank mechanism including a hinge pivot link,
having a first leg and a second leg, and a crank pivot link, having
a first leg, a second leg and a pivot location at an intersection
of the first and second pivot legs of the crank pivot link, with
the first leg of the hinge pivot link being pivotally attached to
the hinge arm, the second leg of the hinge pivot link being
pivotally attached to the first leg of the crank pivot link, the
second leg of the crank pivot link being pivotally attached to the
energy storage device, and the pivot location being configured to
pivotally mount to the vehicle structure.
2. The endgate counterbalance of claim 1 wherein the energy storage
device is a gas strut.
3. The endgate counterbalance of claim 1 wherein the energy storage
device is a spring.
4. The endgate counterbalance of claim 1 wherein the energy storage
device is a torsion rod.
5. The endgate counterbalance of claim 1 wherein the hinge pivot
link is L-shaped.
6. The endgate counterbalance of claim 5 wherein the crank pivot
link is L-shaped.
7. The endgate counterbalance of claim 1 wherein the crank pivot
link is L-shaped.
8. A vehicle comprising: vehicle structure having an endgate with a
hinge pivotally mounted thereto and movable between a closed
position and a fully open position; and an endgate counterbalance
including a hinge arm extending from the hinge and pivotally fixed
relative to the endgate; an energy storage device having a first
end and a second end configured to mount to vehicle structure, the
energy storage device configured to store and dissipate potential
energy as the first end is moved relative to the second end; and a
crank mechanism pivotally connected between the hinge arm and the
energy storage device; the endgate counterbalance configured to
provide no rotational bias to the endgate when the endgate is in a
cross-over position between the closed position and the fully open
position and to provide a rotational bias to the endgate when the
endgate is not in the cross-over position.
9. The vehicle of claim 8 wherein the vehicle structure includes a
box bed, and the energy storage device and the crank mechanism are
located under the box bed.
10. The vehicle of claim 8 wherein the energy storage device is a
gas strut.
11. The vehicle of claim 8 wherein the energy storage device is a
spring.
12. The vehicle of claim 8 wherein the energy storage device is a
torsion rod.
13. The vehicle of claim 8 wherein the crank mechanism includes a
hinge pivot link, having a first leg and a second leg, and a crank
pivot link, having a first leg, a second leg and a pivot location
at an intersection of the first and second pivot legs of the crank
pivot link, with the first leg of the hinge pivot link being
pivotally connected to the hinge arm, the second leg of the hinge
pivot link being pivotally connected to the first leg of the crank
pivot link, the second leg of the crank pivot link being pivotally
attached to the energy storage device, and the pivot location being
pivotally connected to the vehicle structure.
14. The vehicle of claim 8 wherein the hinge pivot link is
L-shaped.
15. The vehicle of claim 8 wherein the crank pivot link is
L-shaped.
16. A method of moving an endgate of a vehicle between a closed
position and a fully open position, the method comprising the steps
of: (a) inducing a zero rotational bias by an endgate
counterbalance on the vehicle endgate when the vehicle endgate is
in a cross-over position located between the closed position and
the fully open position; (b) inducing a rotational bias away from
the closed position by the endgate counterbalance when the endgate
is located between the cross-over position and the closed position;
and (c) inducing a rotational bias away from the open position by
the endgate counterbalance when the endgate is located between the
cross-over position and the fully open position.
17. The method of claim 16 wherein the rotational bias of the
endgate counterbalance is induced by an energy storage device
coupled to a hinge of the endgate via a crank mechanism.
18. The method of claim 17 wherein the energy storage mechanism
stores and releases potential energy as first end of the energy
storage device is moved relative to a second end of the energy
storage device.
19. The method of claim 18 wherein the energy storage device is a
gas strut and the potential energy is stored and released as the
first end is moved linearly relative to the second end.
20. The method of claim 18 wherein the energy storage device is a
torque rod and the potential energy is stored and release as the
first end is rotated relative to the second end.
Description
BACKGROUND OF INVENTION
[0001] The present invention relates generally to vehicle endgates,
and more particularly to a counterbalance for a vehicle
endgate.
[0002] Conventional pickup trucks have an endgate that pivots from
a vertical closed position rearward and downward to a horizontal
open position for ease in loading and unloading cargo from the bed
of the pickup. For some people, however, the amount of effort
required to lift the endgate from its open position in order to
close it is undesirably high. Thus, some pickup manufacturers have
added mechanisms to assist in lifting the tailgate from its open
position while one is closing the endgate.
[0003] For example, some have added torsion rods or vertically
extending gas cylinders connected to the endgate hinge assembly.
These devices store energy as the endgate is moved from its closed
position to its fully open position, with the energy being used to
assist a person when closing the endgate. While the torsion rod
provides assist with lift effort, it does not provide any damping
effect, which may be desirable when moving the endgate between its
open and closed positions. The gas cylinder also has drawbacks in
that it may interfere with the tail lamp housing, creating a
packaging problem within the vehicle. Moreover, neither of these
designs assists with maintaining the endgate (and hinge) in a
position desirable for removal of the endgate from (and reassembly
of the endgate to) the vehicle.
SUMMARY OF INVENTION
[0004] An embodiment contemplates an endgate counter balance for
use with an endgate of a vehicle having a hinge about which the
endgate pivots between a closed position and a fully open position.
The endgate counterbalance may comprise a hinge arm, an energy
storage device and a crank mechanism. The hinge arm may extend from
the hinge and be pivotally fixed relative to the endgate. The
energy storage device may have a first end and a second end
configured to mount to vehicle structure, and be configured to
store and dissipate potential energy as the first end is moved
relative to the second end. The crank mechanism may include a hinge
pivot link, having a first leg and a second leg, and a crank pivot
link, having a first leg, a second leg and a pivot location at an
intersection of the first and second pivot legs of the crank pivot
link. The first leg of the hinge pivot link is pivotally attached
to the hinge arm, the second leg of the hinge pivot link is
pivotally attached to the first leg of the crank pivot link, the
second leg of the crank pivot link is pivotally attached to the
energy storage device, and the pivot location is configured to
pivotally mount to the vehicle structure.
[0005] An embodiment contemplates a vehicle including vehicle
structure having an endgate with a hinge pivotally mounted thereto
and movable between a closed position and a fully open position.
The vehicle also has an endgate counterbalance including a hinge
arm extending from the hinge and pivotally fixed relative to the
endgate; an energy storage device having a first end and a second
end configured to mount to vehicle structure, the energy storage
device configured to store and dissipate potential energy as the
first end is moved relative to the second end; and a crank
mechanism pivotally connected between the hinge arm and the energy
storage device. The endgate counterbalance is configured to provide
no rotational bias to the endgate when the endgate is in a
cross-over position between the closed position and the fully open
position and to provide a rotational bias to the endgate when the
endgate is not in the cross-over position.
[0006] An embodiment contemplates a method of moving an endgate of
a vehicle between a closed position and a fully open position, the
method comprising the steps of: inducing a zero rotational bias by
an endgate counterbalance on the vehicle endgate when the vehicle
endgate is in a cross-over position located between the closed
position and the fully open position; inducing a rotational bias
away from the closed position by the endgate counterbalance when
the endgate is located between the cross-over position and the
closed position; and inducing a rotational bias away from the open
position by the endgate counterbalance when the endgate is located
between the cross-over position and the fully open position.
[0007] An advantage of an embodiment is that the endgate
counterbalance assists with lifting the endgate during a closing
event by reducing the effort during the initial portion of endgate
travel from its horizontal while also assisting in reducing
potential squeak and rattle issues by preloading latches that keep
the endgate in its closed position. An embodiment may also include
the provision for damping during endgate opening and also during
the last portion of motion into the fully closed position.
[0008] An advantage of an embodiment is that the endgate
counterbalance provides a cross-over position when partially opened
that allows for easier removal and re-installation of the endgate
to the vehicle.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a side view looking inboard at a portion of a
pickup truck.
[0010] FIG. 2 is a side view of a portion of a pickup truck,
including part of an endgate and an endgate counterbalance.
[0011] FIG. 3 is a perspective view looking aft and inboard at a
portion of a pickup truck.
[0012] FIG. 4 is a side view of an endgate and endgate
counterbalance, in an endgate closed position.
[0013] FIG. 5 is a side view of a portion of an endgate and endgate
counterbalance, in an endgate open position.
[0014] FIG. 6 is a schematic side view of the geometry for a
portion of the endgate and endgate counterbalance, in the endgate
closed position.
[0015] FIG. 7 is a schematic side view similar to FIG. 6, but
illustrating the endgate in a partially open, cross-over
position.
[0016] FIG. 8 is a schematic side view similar to FIG. 6, but
illustrating the endgate in a fully open position.
[0017] FIG. 9 is a side view of an endgate counterbalance according
to a second embodiment.
[0018] FIG. 10 is a side view of a portion of vehicle structure and
an endgate counterbalance according to a third embodiment.
[0019] FIG. 11 is a perspective view, on a reduced scale, of the
embodiment of FIG. 10.
DETAILED DESCRIPTION
[0020] Referring to FIG. 1, a portion of a vehicle (pickup truck)
body, indicated generally at 20, is shown. The body 20 includes a
box 22 having a box bed 24 (i.e., the floor of the box 22), which
can be seen located inboard of a wheel well opening 26 in a rear
quarter panel 28. The rear quarter panel 28 also includes a brake
light opening 30 and a recess 32 within which a bumper (not shown)
extends. The pickup body 20 has an endgate 34 mounted at the
rearmost portion of the box 22.
[0021] Referring now to FIGS. 1-5, the endgate 34 is shown in both
a vertical, closed position (FIGS. 1-4) and a horizontal, fully
open position (FIG. 5). The endgate 34 has an aft (outer) surface
36 and a forward (inner) surface 38. A conventional latch assembly
(not shown) may be employed to hold the endgate 34 in its closed
position, and a conventional cable assembly (not shown) may be
employed to hold the endgate 34 in its fully open position. The
endgate 34 also includes a pair of hinges 40 (only one shown)
pivotally connected to box side hinge structure 41 and defining a
pivot axis 44 about which the endgate 34 pivots. When referring
herein to two components being pivotally connected, this means that
they are connected together but can pivot relative to one another.
Such an arrangement may be achieved, for example, when the
components have aligned holes, with a rivet or bolt extending
through the holes, thus holding the components together while
allowing them to pivot about the rivet/bolt axis.
[0022] A hinge arm 42 extends laterally from the hinge 40 and is
pivotally fixed relative to the endgate 34. The hinge arm 42
includes a crank attachment hole 46 for pivotally connecting to a
crank mechanism 48 of an endgate counterbalance 50.
[0023] The crank mechanism 48 includes an L-shaped hinge pivot link
52 and an L-shaped crank pivot link 54. The hinge pivot link 52
includes a first pivot hole 56, through a first leg 60, that
pivotally connects to the crank attachment hole 46 and a second
pivot hole 58, through a second leg 62, that pivotally connects to
a first pivot hole 64 in a first leg 66 of the crank pivot link 54.
The crank pivot link 54 also includes a body pivot hole 68 located
at an intersection of the first leg 66 and a second leg 70. The
body pivot hole 68 is used to pivotally mount the crank pivot link
54 to structure 72, which is fixed relative to the body 20. The
second leg 70 includes a second hole 74 that pivotally connects to
a first end 78 of an energy storage device 80, which is also part
of the endgate counterbalance 50.
[0024] The energy storage device 80 in the first embodiment is a
gas strut, which includes a rod 82. The first end 78 of the rod 82
is attached to the crank mechanism 48 with the rod 82 extending
through box side structure 88, and telescopically mounting in a gas
cylinder 84. The gas cylinder 84 is pivotally mounted to a mounting
bracket 86 that mounts to vehicle structure under the box bed 24.
The crank mechanism 48 allows the gas strut 80 to extend forward in
a generally horizontal orientation. Thus, packaging concerns
relating to a vertically mounted gas strut and tail lamp assembly
(not shown) are avoided. Moreover, in the case of a gas strut, this
particular energy storage device 80 also provides a damping
function while one is pivoting the endgate 34.
[0025] The operation of the endgate counterbalance 50 of FIGS. 1-5
will be discussed with reference to schematic FIGS. 6-8. The
phantom lines in FIGS. 6-8 extend between the various pivot points
of the endgate counterbalance 50. With the endgate 34 in its closed
position (FIG. 6), the hinge arm 42 extends downward in a generally
vertical direction. This position of the hinge arm 42 positions the
links 52, 54 of the crank mechanism 48 so that the gas strut
(energy storage device) 80 is somewhat compressed. This compression
produces a bias in the endgate opening direction. By having this
bias, the endgate 34 preloads the latch assembly (not shown) that
holds the endgate 34 closed, thus reducing the potential for squeak
and rattle. Moreover, during the last portion of the closing
movement to the fully closed position, the endgate counterbalance,
having this opening direction bias, will feel as if this last part
of the motion is being damped, creating a desirable feel for the
person closing the endgate 34.
[0026] As the endgate 34 begins to open, the hinge arm 42 will
pivot the crank attachment hole 46 forward and upward, actuating
the crank mechanism 48 such that the gas strut 80 moves toward its
uncompressed position. The endgate 34, then, will reach a
cross-over position (shown in FIG. 7) where the endgate
counterbalance 50 does not exert a bias in either the opening or
closing direction. Pivoting of the endgate 34 in either direction
from this position will create a bias back toward this position.
The cross-over position allows for greater ease in removal and
installation of the endgate 34 from the body 20 since, when the
endgate 34 is removed, the biases of the endgate counterbalance
will tend to hold the hinge assemblies and locating features (not
shown) in place.
[0027] As the endgate 34 is rotated past the cross-over position
toward the full open position (shown in FIG. 8), the hinge arm 42
will pivot into a generally horizontal position. This pivoting will
cause the crank mechanism 48 to again compress the gas strut 80,
creating a bias in the endgate closing direction. Thus, when one
lifts up on the endgate 34 to close it, the endgate counterbalance
50 will assist by initially biasing the endgate toward the closed
position. Moreover, with the energy storage device 80 being a gas
strut, the motion will be damped, creating a desirable feeling for
the person moving the endgate 34.
[0028] FIG. 9 illustrates a second embodiment. Since this
embodiment is similar to the first, similar element numbers will be
used for similar elements, but employing 100-series numbers. In
this embodiment, the energy storage device 180 employed is a
spring. While not providing all of the damping effect of a gas
strut, it may reduce the cost of the overall endgate counterbalance
150. In this embodiment, the hinge 140 still includes a hinge arm
142 that is pivotally connected to the first leg 160 of the hinge
pivot link 152. Also, the second leg 162 of the pivot link 152
still pivotally connects to the first leg 166 of the crank pivot
link 154, which pivotally connects to structure 172 at the body
pivot hole 168. Also, the second leg 170 of the crank pivot link
154 connects to a first end of the spring 180. However, the L-shape
of the crank pivot link 154 may be more of a closed angle to
accommodate the connection of the forward end 186 of the spring 180
to vehicle structure (not shown in FIG. 9). The endgate
counterbalance 150 still functions to provide for a cross-over
position, thus allowing for the same functionality as the first
embodiment.
[0029] FIGS. 10-11 illustrate a third embodiment. Since this
embodiment is similar to the first, similar element numbers will be
used for similar elements, but employing 200-series numbers. In
this embodiment, the energy storage device is a torque rod 280
extending horizontally under the box bed 224. While not providing
all of the damping effect of a gas strut, it has less sensitivity
to temperature changes than the gas strut. The hinge 240 still
includes the hinge arm 242 that is pivotally connected to the hinge
pivot link 252. Also, the hinge pivot link 252 still pivotally
connects to the first leg 266 of the crank pivot link 254, which
pivotally connects to structure 272 at the body pivot hole 268. The
second leg 270 of the crank pivot link 254 connects to the first
end of the torque rod 280. However, the torque rod 280 then extends
through the center of the body pivot hole 268 before extending
toward a second end (not shown) that is rotationally fixed to
vehicle structure (not shown). The endgate counterbalance 250 still
functions to provide for a cross-over position, thus allowing for
the same functionality as the first and second embodiments.
[0030] While certain embodiments of the present invention have been
described in detail, those familiar with the art to which this
invention relates will recognize various alternative designs and
embodiments for practicing the invention as defined by the
following claims.
* * * * *