U.S. patent application number 09/766282 was filed with the patent office on 2002-07-25 for torsion bar for a door lid.
Invention is credited to Arora, Anita, Nicholas, Nicole.
Application Number | 20020096905 09/766282 |
Document ID | / |
Family ID | 25075965 |
Filed Date | 2002-07-25 |
United States Patent
Application |
20020096905 |
Kind Code |
A1 |
Nicholas, Nicole ; et
al. |
July 25, 2002 |
TORSION BAR FOR A DOOR LID
Abstract
A torsion bar for use in raising a vehicle trunk lid has a
center extender portion to increase the effective length of the
torsion bar. The extender portion generally includes three U-shaped
portions of the torsion bar which extend on a generally horizontal
plane. Two of the U-shaped portions extend transversely across the
vehicle. The third extends longitudinally. A pair of lifting
portions extend radially at either end of the torsion bar. The
lifting portions engage a link pivotally attached to hinge arms to
form a biasing force to lift the trunk lid. The increased effective
length of the torsion bar permits the torsion bar to produce
desired lifting criteria while preventing the torsion bar from
being overstressed.
Inventors: |
Nicholas, Nicole; (US)
; Arora, Anita; (Bloomfield Hills, MI) |
Correspondence
Address: |
Thomas E. Anderson
Gifford, Krass, Groh, Sprinkle, Anderson &
Citkowski, P.C.
280 North Old Woodward, Suite 400
Birmingham
MI
48009
US
|
Family ID: |
25075965 |
Appl. No.: |
09/766282 |
Filed: |
January 19, 2001 |
Current U.S.
Class: |
296/76 |
Current CPC
Class: |
F16F 1/14 20130101; E05F
1/1033 20130101; E05F 1/1238 20130101 |
Class at
Publication: |
296/76 |
International
Class: |
B62D 025/10 |
Claims
We claim:
1. A torsion bar for use in combination with a door and a pair of
hinge assemblies, said torsion bar comprising: an extender portion
and a pair of lifting portions spaced apart a predetermined
distance, said torsion bar further having a pair of rod portions,
each of said rod portions extending from one of said lifting
portions towards said extender portion, said extender portion
having a longitudinal axis extending transversely to a plane
extending through said pair of hinge assemblies, said extender
portion having at least one portion extending in a direction away
from said longitudinal axis, said extender portion and said rod
portions having a combined length greater than said predetermined
distance between said pair of lifting portions having a lifting
portions engaging one of said pair of hinge assemblies to be
twisted away from said center portion when said door is closed.
2. The torsion bar of claim 1 wherein said extender portions have a
pair of transverse portions connected together by a center
portion.
3. The torsion bar of claim 2 wherein said pair of transverse
portions have an equal length.
4. The torsion bar of claim 3 wherein each of said pair of
transverse portions have a generally U-shape.
5. The torsion bar of claim 1 wherein said center attachment
portion has a generally U-shape.
6. The torsion bar of claim 3 wherein said pair of rod portions
have a length greater than said transverse portions of said
extender portion.
7. A lifting assembly for raising a door with respect to a deck,
said lifting assembly comprising: a pair of hinge assemblies
extending between said deck and said door, a torsion bar having a
pair of lifting portions and an extender portion, said extender
portion engaging said deck, each of said pair of lifting portions
engaging one of said hinge assemblies, said torsion bar further
having at least one rod portion extending between said extender
portion and one of said lifting portions, said extender portion
having at least one transverse portion extending in a direction
away from said center portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a torsion bar and, more
particularly, to a torsion bar for use in raising a door lid.
[0003] 2. Description of the Prior Art
[0004] Torsion bars have been used in assisting in the opening and
raising doors and lids of vehicles. Typically, the torsion bar has
at least two radially extending U-shaped portions. These portions
are typically formed by bending the bar. When the door is open, one
of the radially extending portions contacts the underside of the
door and the other radially extending portion contacts the
structure adjacent the door. When the door is closed, it pushes one
of the radially extending portions towards the other, twisting the
rod and creating a spring-like tension in the rod.
[0005] Japanese Publication 2875027 discloses a torsion bar formed
to raise the engine cover of a forklift truck. The torsion bar has
a door lid lifting portion extending radially outwardly from the
bar adjacent each of a pair of hinges. A center portion extends in
a radially opposite direction to abut the inside of the engine
compartment. When the engine cover lid is closed, the door lid arm
portions are twisted towards the center arm to create a torsion in
the torsion bar acting in opposition to the closure. If the weight
of the lid is greater than the biasing force of the torsion bar,
the engine lid will remain in the closed position. When the engine
cover is lifted to access the compartment, the biasing force of the
torsion bar assists in raising the lid and holding the lid in the
open position.
[0006] It is also known to use torsion bars to open trunk lids and
hoods in automobiles. However, there are a number of parameters
which are desirable in designing a door lifting mechanism. It is
desirable to provide a "pop-up" force to raise the trunk lid a
short distance from its locked position without any outside
assistance. It is also desirable to provide a "hold open" force
which will support the door in any position where it is placed. It
is desirable to have this force for use between the "pop-up"
position and the approximately sufficient force to hold the door
open in its fully extended position. In some cases, it is desirable
that the torsion bar provide sufficient force to support in
intermediate positions in between the pop-up position and the
midway open position. Finally, the door should be forced to and
held at the fully open position when raised by a person beyond the
midway position. Thus, the torsion bar must have a large enough
moment to open and support the door in this range of operation.
[0007] It has been difficult to find a good combination of all the
variables to meet these design parameters. The length of typical
torsion bars is such that these bars do not provide sufficient
"hold open" force to support the door at the intermediate
positions. Accordingly, it is known to use a pair of torsion bars
such as disclosed in Japanese Patent No. 55-94278. Each bar has a
radially extending portion which is positioned against one of the
hinge links. The torsion bars are then mounted to cross each other.
However, such an installation is costly to build and install.
Accordingly, it would be desirable to have a single torsion bar
which met the necessary design parameters and reduces the mass and
cost of production.
SUMMARY OF THE INVENTION
[0008] The invention relates to a torsion bar having an effective
additional length. The effective additional length permits the
torsion bar to produce a greater torsion bar moment without
exceeding the design stress. The torsion bar includes a length
extender portion disposed between a pair of radially extending
lifting portions. In the preferred embodiment, the length extender
portion is formed by bending a center portion of the rod into a
shape. The shape will depend on the space available to accept the
extender portion. In this way the effective length of the torsion
bar is increased by the length of the extender portion thereby
providing the desired "pop opening" force, "holding" force and
moment to support the trunk lid in the "hold open" position.
BRIEF DESCRIPTION OF THE DRAWING
[0009] Reference is made to the attached drawing of the present
invention wherein reference numerals and description refer to like
parts throughout the several views and in which:
[0010] FIG. 1 is a perspective view of a vehicle and vehicle trunk
lid with a torsion bar in accordance with the invention supporting
the trunk lid;
[0011] FIG. 2 is a side view of the trunk lid and hinge
mechanism;
[0012] FIG. 3 is a top view of the torsion bar and the hinge
mechanism in position in a vehicle in accordance with the
invention; and
[0013] FIG. 4 is a partial perspective view of a hinge assembly in
accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] A novel torsion bar 10 for opening a trunk lid 12 for a
luggage compartment 14 of a vehicle 16 is shown in FIG. 1. The
trunk lid 12 is movably supported by hinges 18 as shown in FIGS. 2
and 4. As shown in FIG. 4, each hinge 18 includes a hinge arm 20
which slides through an aperture 22.
[0015] As shown in FIG. 2, the trunk lid 12 moves with the hinge
arm 20 in a hinge support 24 between a closed position "A" and an
open position "B". The hinge support 24 is mounted within the
luggage compartment 14. A pin 28 holds the hinge arm 20 from
sliding through the aperture 22 in the hinge support 24. A link 26
extends between the hinge arm 20 and a lifting portion 30 of the
torsion bar 10. One end of the link 26 is attached by a pin 32 to
the hinge arm 20. The other end of the link 26 has a notch 34 to
accept the lifting portion 30 of torsion bar 10. As discussed
below, the link 26 twists the torsion bar 10 as the trunk lid is
closed (FIG. 2).
[0016] As shown in FIG. 3, the torsion bar 10 is mounted to extend
transversely across the vehicle beneath a rear deck 36. The torsion
bar 10 is roughly formed in a single piece of ASTM 8227 or SAE 9254
or similar material. The torsion bar 10 has an extender portion 38
centrally disposed between a pair of rod portions 40 and the
lifting portions 30. Each lifting portion 30 is adjacent an end of
the torsion bar 10 and displaced angularly approximately 60.degree.
from the center portion which extends along a horizontal plane when
installed. In the preferred embodiment, the torsion bar is bent
into shape from a single rod. However, the torsion bar could be
formed by welding one or more segments together.
[0017] As shown in FIG. 3, each lifting portion 30 is firmed by
bending into a generally U-shape. A transverse portion 42 engaging
the link 26 and extends between a pair of radially extending arms
44 for engaging the link 26 to assist in raising the trunk lid 12.
The rod portions 40 extend between the lifting portions 30 and the
extender portion 38. The rod portions 40 may be bowed or curved to
accommodate the placement of rear speakers 46 in the rear deck 36
as shown in FIG. 3.
[0018] The torsion bar 10 is bent approximately 180.degree. at an
inner end of each of the rod portions to the extender portion 38.
The extender portion 38 extends on a horizontal plane along a
longitudinal axis which is parallel with a longitudinal axis of a
vehicle. In the preferred embodiment, the extender portion has a
center portion 50 extending along the longitudinal axis between a
pair of transverse portions 48 which extend in opposite directions
along an axis which extends transversely across the vehicle. The
center portion 50 and transverse portions 48 are formed as in an
inverted U-shape with the openings adjacent each other.
[0019] A bracket 52 is mounted beneath the rear deck 36 of the
luggage compartment 14 to hold the torsion bar 10. The bracket 52
has a hook portion which engages the center portion 50 of torsion
bar 10. The length of the extender portion 38 is chosen to provide
the torsion bar 10 with the desired overall length to provide the
desired torsion. In the preferred embodiment, the length of the
torsion bar between the lifting portions 30 is approximately
150-200% of the distance between the hinge supports 24.
OPERATION
[0020] The trunk lid and torsion bar are installed in the vehicle
in the normal fashion. The hinge is mounted first and then the
trunk lid is mounted to the hinge. The torsion bar 10 is then
mounted in the vehicle. The lifting portions 30 of the torsion bar
10 are placed in the notches 34 of the links 26. The transverse
portion of the center portion 50 is snapped into the hook portion
of the bracket 52. When the trunk lid 12 is closed, the links 26
displace the lifting portions 30 in an arc toward the front of the
vehicle 16.
[0021] The displacement of the lifting portions 30 during closing
twists the torsion rod 10 to develop a lifting force. The lifting
force length of the torsion bar 10 has been increased by the
extender portion 38 so that the torsion bar 10 provides sufficient
"pop up" force and holding force while not overstressing the
torsion bar 10. The torsion bar 10 effectively meets the desired
lifting criteria.
[0022] The discussion and examples hereinabove represent a specific
embodiment of applications of the present invention. Within the
guidelines given herein, one of skill in the art could readily
recognize variations of the invention. Therefore, it is to be
understood that the foregoing discussion, description and example
are illustrative of a particular embodiment of the present
invention but are not meant to be limitations upon the practice
thereof. It is the following claims, including all equivalents,
which define the scope of the invention.
* * * * *