Title: Combination pickup truck liftgate/tailgate
Abstract: A liftgate/tailgate assembly for a vehicle having a chassis and a cargo area, such cargo area comprising a bed and one or more vertical sidewalls mounted to the vehicle chassis, such liftgate/tailgate assembly comprising a tailgate which, when rotated into an open tailgate position, forms a liftgate/tailgate platform to support a load to be lifted, and one or more linkage assemblies pivotably mounted to the tailgate which permit the liftgate/tailgate platform to be translated both vertically and horizontally relative to the cargo area of the vehicle, while permitting rear impact protection to be mounted on the vehicle and method for lifting a load into a vehicle cargo area.
Patent Number: 6,893,203 Issued on 05/17/2005 to Anderson, et al.
| Inventors:
|
Anderson; Jeffrey A. (Belleville, MI);
Baker; Jon F. (Bloomfield Hills, MI);
Kennedy; Michael E. (Fowlerville, MI)
|
| Assignee:
|
Meridian Automotive Systems, Inc. (Dearborn, MI)
|
| Appl. No.:
|
175635 |
| Filed:
|
June 20, 2002 |
| Current U.S. Class: |
414/557; 414/467; 414/545 |
| Intern'l Class: |
B60P 001/00 |
| Field of Search: |
414/557,556,545,546,539,467
280/400,401
|
References Cited [Referenced By]
U.S. Patent Documents
| 3077275 | Feb., 1963 | Wise.
| |
| 3305112 | Feb., 1967 | Brown.
| |
| 3467266 | Sep., 1969 | Vanderjagt.
| |
| 3637097 | Jan., 1972 | Horowitz.
| |
| 3688649 | Sep., 1972 | Hostetler.
| |
| 3700123 | Oct., 1972 | Corley, Jr.
| |
| 3889827 | Jun., 1975 | Fine.
| |
| 4007844 | Feb., 1977 | Perkins.
| |
| 4787809 | Nov., 1988 | Zrostlik.
| |
| 4813842 | Mar., 1989 | Morton.
| |
| 4991890 | Feb., 1991 | Paulson.
| |
| 5470188 | Nov., 1995 | Ebato.
| |
| 5513943 | May., 1996 | Lugash et al.
| |
| 5641262 | Jun., 1997 | Dunlop et al.
| |
| 5941677 | Aug., 1999 | De Boer.
| |
| 6102646 | Aug., 2000 | Bass et al.
| |
| Foreign Patent Documents |
| 2 276 592 | Oct., 1994 | GB.
| |
Primary Examiner: Lillis; Eileen D.
Assistant Examiner: Lowe; Michael
Attorney, Agent or Firm: McDonnell Boehnen Hulbert & Berghoff LLP
Parent Case Text
This application claims priority of U.S. patent application Ser. No. 60/299,661.
Claims
1. A liftgate/tailgate assembly for a vehicle having a chassis and a cargo area,
such cargo area comprising a bed and one or more vertical sidewalls mounted to
the vehicle chassis, such liftgate/tailgate assembly comprising
(a) a tailgate which, when rotated into an open tailgate position, forms a liftgate/tailgate
platform to support a load to be lifted;
(b) one or more linkage assemblies pivotably mounted to the tailgate which permit
the liftgate/tailgate platform to be translated both vertically and horizontally
relative to the cargo area of the vehicle;
(c) rear impact protection mounted on the vehicle or on one or more of the liftgate/tailgate
linkage assemblies, such that the rear impact protection is directly adjacent to
the tailgate when the tailgate is in a closed position wherein the rear impact
protection is attached directly to one or more of the linkage assemblies, and to
no other portion of the vehicle.
2. The liftgate/tailgate assembly of claim 1 Wherein the rear impact protection
is attached to one or more crosslink(s) of the linkage assemblies.
3. The liftgate/tailgate assembly of 2 wherein a portion of the rear impact protection
abuts structural members connected to the vehicle chassis only when the liftgate/tailgate
assembly is in a closed position.
4. A method for lifting a load into the cargo area of a vehicle while maintaining
at least some rear impact protection, such vehicle having a chassis, a rear bumper
beam, and a cargo area comprising a bed mounted to the vehicle chassis and one
or more vertical sidewalls, such method comprising
(a) pivotably mounting a tailgate to a movable vertical link, and translating
the vertical link, and the associated tailgate, from a lowered position, both vertically
and horizontally, with one or more cross-links, to align the tailgate with the
bed of the cargo area of the vehicle;
(b) mounting the rear bumper beam to one or more of the linkage assemblies, but
not to any other part of the vehicle;
(c) positioning structural members that are connected to the vehicle chassis
so that they abut a portion of the rear bumper beam when the tailgate is in a closed
position and form part of the rear impact protection of the vehicle.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to tailgates and liftgates for motor vehicles. Specifically,
the invention relates to a combination liftgate/tailgate for a pickup truck that
matches the styling of the vehicle, maximizes the useable cargo space and operates
as a standard tailgate when the liftgate is not in use.
2. Description of the Related Art
Lift assemblies are used in a variety of vehicles, such as large trucks, mini
vans, and pickup trucks for elevating heavy objects between ground level and bed
level of a vehicle. They are typically mounted on the rear or the vehicle, and
comprise a lifting platform, an electric or hydraulic mechanism that operates the
lifting platform, and controls. When the lift is not in use, the platform can be
folded up to serve as a gate.
Such liftgates are typically installed on the vehicle as a retrofit assembly
often in place of an existing tailgate. Consequently, their styling generally does
not match that of the vehicle to which they are installed, particularly in the
case of pickup trucks because the tailgate is removed. Furthermore, the typical
retrofit liftgate assembly occupies a portion of the bed of the vehicle, thereby
reducing the vehicle's cargo carrying capacity. As well, such liftgates do not
operate in the typical manner as tailgates when the lift is not in use because
they require the attachment of substantial additional hardware to the vehicle bed
to retain the liftgate in an upright, non-use position.
SUMMARY OF THE INVENTION
The invention comprises a combination liftgate/tailgate for a pickup truck that
matches the styling of the vehicle, maximizes the useable cargo carrying capacity,
and operates as a tailgate in the normal manner when the lift is not in use. The
lift mechanism is concealed when the lift is not in use, and the controls for the
lift mechanism can be incorporated into a key fob.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a respective view of the combination liftgate/tailgate for a vehicle
in a closed position according to the invention;
FIG. 2 is a perspective view of the combination liftgate/tailgate assembly of
FIG. 1 showing its use as a conventional pickup truck tailgate and as a liftgate
in the fully raised position;
FIG. 3 is a perspective view of the combination liftgate/tailgate assembly of
FIG. 1 showing its use as a liftgate in the fully lowered position;
FIG. 4 is a close-up view of a key fob incorporating the liftgate control buttons
for the combination liftgate/tailgate assembly of FIG. 1 with substantially all
of the vehicle removed for clarity;
FIG. 5 is a perspective view of the combination liftgate/tailgate assembly of
FIG. 1 showing its use as a liftgate in an intermediate position;
FIG. 6 is an exploded view of the combination liftgate/tailgate assembly of
FIG. 1 with substantially all of the vehicle removed for clarity;
FIG. 7 is an exploded view of an alternative embodiment of the combination liftgate/tailgate
assembly of FIG. 1;
FIG. 8 is a perspective view of the alternative embodiment of FIG. 7 in an assembled configuration;
FIG. 9 is a perspective view of the combination liftgate/tailgate assembly of
FIG. 7 mounted on a conventional pickup truck tailgate and in a closed position;
FIG. 10 is a perspective view of the combination liftgate/tailgate assembly
of FIG. 7 showing its use as a conventional pickup truck tailgate and as a liftgate
in the fully raised position;
FIG. 11 is a detailed view of the vertical leg of the combination liftgate/tailgate
of FIG. 7 showing positions of an upper link and a lower link when the liftgate
is in a fully raised position;
FIG. 12 is a perspective view of the combination liftgate tailgate assembly
of FIG. 7 showing the liftgate in an intermediate position (between the fully raised
position and a fully lowered position);
FIG. 13 is a perspective view of the combination liftgate/tailgate assembly
of FIG. 7 showing its use as a liftgate in the fully lowered position;
FIG. 14 is a detailed view of the liftgate operating mechanism of the alternative
embodiment of FIG. 7 showing the pivoting of the lower link by extension of the
piston rod;
FIG. 15 is a close-up view of a key fob incorporating liftgate control buttons
for controlling the operation of the combination liftgate/tailgate assembly of
FIG. 7; and
FIG. 16 is a detailed view of a tailgate retainer block for the alternative
embodiment of FIG. 7.
FIG. 17 is a perspective view of an alternative combination liftgate/tailgate assembly.
FIG. 18 is a detailed view of the liftgate operating mechanism of the alternative
embodiment of FIG. 17 showing the various links in the liftgate lowered position.
FIG. 19 is a detailed view of the liftgate operating mechanism of the alternative
embodiment of FIG. 17 showing the various links in the liftgate raised position.
FIG. 20. shows a variation of the liftgate embodiment shown in FIGS.
7-11 in a closed position.
FIG. 21 shows the embodiment variation in FIG. 20 in the liftgate lowered position.
FIG. 22 is a cross-section taken along the line 22—22 in
FIG. 21.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, a vehicle
2, such as a pickup truck,
comprises a cab
4, a cargo bed
6 having sidewall edges
140
and a tailgate
8 having lateral edges
24 and
26. When closed,
the lateral edges
24 and
26 of the tailgate
8 are brought
into close proximity to the sidewall edges
140 of the bed
6 so that
a rear surface of the pickup truck
22 appears to be unbroken. As described
herein, the invention relates to a combination liftgate,tailgate
9 that
operates as a tailgate between a closed position and an open tailgate position
and as a liftgate to elevate items between a ground surface and the open tailgate position.
Referring to FIGS. 1-3, the combination liftgate/tailgate
9 comprises
a platform
10, opposed linkage assemblies
12, and a drive assembly
16. The drive assembly
16 is interconnected to the linkage assemblies
12 by corresponding cables
14. The linkage assemblies
12 are
interconnected to the platform
10 by corresponding cables
18.
The platform
10 has an inside surface
20, an outside surface
22,
side surfaces having the lateral edges
24 and
26, a bottom surface
28, and a top surface
30, which are combined in a conventional manner
by stamping forming, welding, adhesives, or fasteners into a reinforced tailgate.
The inside surface
20 is constructed of a suitable material, such as sheet
steel, that is capable of supporting a desired payload. The side surfaces
24
and
26 contain linkage recesses
34 adapted to receive the linkage
assemblies
12 when the combination liftgate/tailgate
9 is in the
closed position. The outside surface
22 is constructed of the same sheet
metal as the vehicle exterior, and incorporate styling features complementary to
the overall styling of the vehicle. The platform
10 can incorporate additional
strengthening members, either interiorly or exteriorly depending upon the properties
of the materials used for the inside and outside surfaces, and the desired load-carrying
capacity of the liftgate/tailgate
9.
The platform
10 is provided with a conventional tailgate latch
32
accessible via the outside surface
22 which retracts tailgate latch pins
38 into the lateral edges
24 and
26 and enable the liftgate/tailgate
9 to be moved to the open tailgate position. It will be understood that
the liftgate/tailgate
9 can be operated by a conventional tailgate lock/release
mechanism. The side surfaces
24 and
26 are also provided with anchors
21 for attachment of the tailgate support cables
18, as hereinafter
described. the anchors
21 are attached using conventional fasteners to the
side surfaces
24 an
26, intermediate a top surface
30 and
a bottom surface
28 thereof.
FIG. 6 shows an exploded view of one embodiment of a combination liftgate/tailgate
including linkage assemblies, each of which comprises a mounting link
40,
an upper link
42, a lower link
44, a vertical link
46, and
fasteners as hereinafter described. The mounting link
40 is an elongated
member having a first end
50 and a second end
52. The mounting link
40 has a series of apertures
54,
56,
58,
60,
and
63 thereon. The apertures
54 and
56 are provided adjacent
first and second ends
50 and
52, respectively. The aperture
58
is provided on the mounting link
40 intermediate the apertures
54,
56. The aperture
60 are provided in a spaced relationship along the
mounting link
40 intermediate the two ends
50,
52 thereof
for attaching the mounting link
40 to the sidewall
36 of the truck
bed
6 using fasteners
62. The number and location at the apertures
60 will be determined so that the liftgate/tailgate
9 is securely
mounted to the vehicle sidewalls
36. Slots
63 can be provided on
the mounting link
40 adapted to receive the tailgate latch pins
38
when the liftgate/tailgate
9 is in the closed position.
The upper link
42 is an elongated member having first end
64 and
a second end
66. The upper link
42 is provided with a bend
68
intermediate the first and second ends
64 and
66. The first and second
ends
64 and
66 are provided with apertures
70 and
72
respectively. The upper link
42 is also provided at the first end
64
with an anchor
74 for attachment of the lifting cable
14, as hereinafter described.
The lower link
44 is a similar elongated member having a first end
76
and a second ends
78. The lower link
44 is provided with a bend
80
intermediate the first and second end
78. The first and second ends
76
and
78 are provided with apertures
82 and
84, respectively.
The vertical link
46 is an elongated member having a first end
92
and a second end
94. The first and second ends
92 and
94 are
provided with apertures
96 and
98, respectively. An aperture
100
is provided intermediate and the apertures
96 and
98. The vertical
link
46 is also provided with an anchor
102 intermediate the ends
92 and
94 for attachment of the tailgate support cable
18,
as a hereinafter described. The vertical link
46 is also provided at its
upper end with a slot
63 that is adapted to accommodate the tailgate latch
pins
38 in a position in register with the slot
63 on the mounting
link
40 when the mounting link
40 is aligned with the vertical link
46.
The second end
66 of the upper link
42 is pivotably mounted to
the mounting link
40 by passing a fastener
104 through aligned aperture
58 and
72 thereof. The first end
64 of the upper link
42
is pivotable mounted to the vertical ling
46 by passing a fastener
106
through aligned apertures
96 and
70 thereof.
The second end
78 of the lower link
44 is pivotably mounted to
the mounting link
40 by passing a fastener
108 through aligned apertures
54 and
84 thereof. The first end
76 of the lower link
44
is pivotably mounted to the vertical link
46 by passing a fastener
110
through aligned apertures
100 and
110 thereof. The vertical line
46 is pivotably attached through the aperture
98 with the fastener
112 to the side surfaces
24 and
26. The upper link
42
and the lower line
44 may be alternatively mounted directly to the sidewall
36, eliminating the mounting link
40.
The upper link
42 and the lower link
44 are configured and attached
to the mounting link
40 and the vertical link
46 so that the inside
surface
20 remains parallel to the cargo bed
6 of the vehicle
2
throughout the lifting operation, and the liftgate/tailgate
9 can be closed
as a conventional tailgate. The fasteners
104,
106,
108, and
110 are conventional attachments that may include pins, shafts, bearings,
or bushings, countersunk as needed, so the connected members are allowed to freely
pivot relative to each other.
The aforementioned attachments and pivotal mountings will be dependent upon the
magnitude of the load to be lifted and the requirements that the upper link
42
and the lower link
44 remain parallel to each other, that the platform
10
remain in a level position, during operation of the lift, and that the platform
10 not contact the vehicle bumper
120 or a trailer hitch (not shown)
as the platform
10 is raised and lowered. Vehicle bumper
120 is provided
with cutouts
122 to accommodate linkage assemblies
12 when the platform
10 is in the fully lowered position.
Tailgate support cable
18 is comprised of a suitable material such
as steel wire-wound cable, chain, or other material that is flexible, of sufficient
strength to support the platform
10 when fully loaded, and of sufficient
length to maintain the platform
10 in an orientation level with the cargo
bed
6 of the vehicle during its operation as a liftgate. The tailgate support
cable
18 is attached to the vertical link
46 intermediate of the
ends f the vertical link by the anchor
102, and to the platform
10
by the anchor
21. The anchors
21 and
102 can be any suitable
conventional anchoring device, such as an eye bolt, and the support cable
18
can be attached to the anchors by any of several known ways, including with a fastening
nut, strap, welding etc.
The drive assembly
16, although can be any known drive motor, can be a
conventional 12-volt DC electric motor with a gear-reduction cable drive that is
mounted within the sidewalls
36 of the bed
6 using brackets
130
and fasteners
132. The motor
16 is preferably wired into the vehicle's
12-volt electrical system (not shown). A pulley
86 is mounted to the sidewalls
36 using a fastener
88. The lifting cable
14 passes from the
motor
16 over the pulley
86 through the aperture
56 and connects
to the upper link
42 by the anchor
74. The anchor
74 can be
any suitable conventional anchoring device, like the other anchors
21 and
102, and the lift cable
14 can be attached to the anchor by the previously-described
conventional methods. The lift cable
14 is extended and retracted by the
motor
16 and is controlled by a conventional electric control system, such
as by a switch located in the cab
4. Alternatively, controls
142
for operating the liftgate/tailgate
9 can be incorporated into a key fob
144 utilizing radio-control circuitry (FIG. 4) as is well known in the art
of remote control devices. A conventional pneumatic or hydraulic driven motor can
be employed in place of the electric motor without departing from the scope of
the invention.
The operation of the liftgate/tailgate
9 will now be described. When the
liftgate/tailgate
9 is in the closed position, the upper link
42,
the lower link
44, and the vertical link
46 are brought into generally
vertical alignment with the mounting link
40 and are enclosed by the recess
34 of the platform
10. The liftgate/tailgate
9 can be opened
as a conventional tailgate by operating the tailgate latch
32, which retracts
the tailgate latch pins
38 from the slots
63, which enables the liftgate/tailgate
9 to be rotated down and to the rear by pivoting about an axis defined by
the fastener
112. The rotation of the liftgate/tailgate
9 continues
until the tailgate support cables
18 are fully extended, and the tailgate
is held in the open tailgate position, preferably level with a floor surface of
the cargo bed
6. In the open tailgate position shown in FIG. 2, the vertical
link
46 is in a generally vertical orientation, parallel to the mounting
link
40. The upper link
42 and the lower link
44 remain in
a generally vertical position, generally parallel to each other.
When the liftgate/tailgate
9 is to be operated as a liftgate to move
the platform
10 between the open tailgate position and a lowered position
adjacent to the ground, the control buttons
142 on the key fob
144
are operated to control the extension and retraction of the lifting cable
14.
With reference to FIG. 5, the motor plays out the lifting cable
14 (in the
direction shown by arrow "A" of FIG.
5), which allows the upper link
42
and the lower link
44 to pivot to the rear and downwardly about the pivotal
mountings
104 and
108 (in the direction shown by arrow "B" of FIG.
5) as the platform
10 is lowered (in the direction shown by arrow "C" of
FIG.
5). The upper link
42 and the lower link
44 remain generally
parallel to each other as they rotate. The upper link
42 and the lower link
44 rotate relative to the vertical link
46 about pivots
106
and
110 and, consequently, the vertical link
46 remains in a generally
vertical orientation, parallel to the mounting link
46 remains in a generally
vertical orientation, parallel to the mounting link
40. The desired position
of the platform
10 is determined by the length of the lifting cable
14
extended by the drive assembly
16 and the angular orientation of the platform
10 is determined by the tailgate cables
18. When the lifting cable
14 is completely played out, the platform
10 is lowered to its lowest
position, generally parallel to the cargo bed
6 and preferably adjacent
to the ground (FIG.
3).
When the lift cable
14 is taken up by the drive assembly
16, the
upper link
42 pivots about the pivot
104 in a forward and vertical
direction, with the second end
64 transcribing a generally circular arc
as the upper link
42 is rotated upward. At the same time, the lower link
44 rotates in an upward and forward direction about the pivot
108,
with the second end
76 transcribing a generally circular arc as the lower
link is rotated upward. The platform
10 is elevated to a position generally
level with the cargo bed
6 of the pickup truck
2 while remaining
in a position substantially parallel to the cargo bed
6. When the platform
10 is lifted to the fully elevated position level with the cargo bed
6
of the truck
2, the vertical link
46 is preferably parallel and adjacent
to the mounting link
40. The upper link
42 and lower link
44
are in a generally parallel orientation, adjacent to the vertical link
46
and mounting link
40, with the vertical link, the upper link, and the lower
links
42,
44, and
46 returned to within the recess
34.
The platform
10 can then be closed by pivoting the platform about the pivots
98 so that the tailgate latch pins
38 re-engage within the slots
63.
Referring now to FIGS. 7-16, an alternative embodiment
109 of the
invention will now be described. In this embodiment, the power supply is mounted
beneath the vehicle and the liftgate is operated by a pair of hydraulic pistons.
Referring now to FIGS. 7 and 8, the alternative embodiment
109 of
the invention comprises a liftgate/tailgate
8 generally as previously described,
a linkage assembly
148, and a power actuating assembly
116 with a
mounting assembly
264,
266 for mounting the power actuating assembly
116 to the underside of the vehicle
2. The linkage assembly
148
is mounted to either end of the liftgate/tailgate
8. Each linkage assembly
148 is a mirror image of the other, but is identical to the other in every
respect. Thus, only one linkage assembly will be described.
Each linkage assembly comprises a vertical leg
150, a mounting leg
152,
an upper link
154, and a lower link
156. The vertical leg
150
is an elongated member with an inner face
158, an outer face
160,
and a connecting plate
162 forming a three-sided channel piece with an open
side. Referring also to FIG. 11, the inner face
158 is comprised of a lower
plate
164, an upper plate
166, and a bevel plate
168 interconnecting
the two along a vertical direction. The plates
164-
168 are rigidly
connected, preferably by welding. The bevel plate
168 is inclined from the
plane of the lower plate
164 and the plane of the upper plate
166
to form a bevel portion between the lower plate
164 and the upper plate
166. The lower plate
164 has an aperture
163 for receiving
a conventional bolt or pin for pivotally connecting the lower link
156 to
the vertical leg
150 as hereinafter described. The upper plate
166
has an aperture
167 for receiving a conventional bolt or pin for pivotally
connecting the upper link
154 to the vertical leg
150 as hereinafter
described. The lower plate
164 has an aperture
165 for receiving
a conventional bolt or pin for pivotally connecting a tailgate cable
118
to the vertical leg
150.
The outer face
160 is comprised of a lower plate
170, an upper
plate
172, and a bevel plate
174. The plates
170-
174
are rigidly connected, preferably by welding. The bevel plate
174 is inclined
from the plane of the lower plate
170 and the plane of the upper plate
172
to form a bevel portion between the lower plate
170 and the upper plate
172. The upper plate
172 has an aperture
160 that extends
through the upper plate
172 and the upper plate
166 for receiving
a conventional bolt or pin for pivotally connecting the upper link
154 to
the vertical leg
150 as hereinafter described. The aperture
167 is
axially aligned with the aperture
169 for receipt of the bolt or pin there
through. The vertical leg
150 defines an upper end
176 and a lower
end
178.
The shape of the connecting plate
162 corresponds to the profile defined
by the inner face
158 and the outer face
160 at opposed outer vertical
edge thereof. The connecting plate
162 is rigidly and orthogonally attached
to the inner face
158 and the outer face
160, preferably by welding.
The upper end
176 of the vertical leg
150 thus narrows to a throat
portion where the upper plate
166 is in close proximity to the upper plate
172.
A bearing
180 for pivotally receiving the liftgate/tailgate
8 as
hereinafter described comprises a flange
171 and socket
173. The
socket
173 is rigidly attached to the flange
171, preferably by welding.
The flange
171 is fixedly attached to the lower plate
164 at the
lower end
178 of the vertical leg
150, preferably by welding or a
conventional bolted connection. The liftgate/tailgate
8 can thus pivot between
a vertical position and a horizontal position with respect to the vertical leg
150.
A tailgate latch finger
182 is a generally flat, elongated piece with a
first end
184 and a second end
186. The first end
184 has
a pin aperture
188 there through. The second end
186 is rigidly attached,
preferably by welding, to the upper plate
170 near the upper end
176
of the vertical leg
150 so that the latch finger
182 is extended
orthogonally to the vertical leg
150 toward the bed of the vehicle.
The mounting leg
152 is an elongated member with an inner face
190,
an outer face
192, and a connecting plate
194 forming a three-sided
channel piece with the open side. The inner face
190 is comprised of a lower
plate
196, an upper plate
198, and a bevel plate
200.
The plates
196-
200 are rigidly interconnected, preferably by welding.
The bevel plate
200 is inclined fro the plane of the lower plate
196
and the plane of the upper plate
198 to form a bevel portion between the
lower plate
196 and the upper plate
198. The lower plate
196
has an aperture
202 for receiving a bearing
204 for pivotally mounting
a connecting bar
206 to the mounting leg
152 as hereinafter described.
The upper plate
198 has an aperture
208 for receiving a conventional
bolt or pin for pivotally connecting the upper link
154 to the mounting
leg
152 as hereinafter described. The outer face
192 has an aperture
210 that is axially aligned with the aperture
202, and an aperture
212 that is axially aligned with the aperture
208.
The plates
190-
194 are rigidly connected, preferably by welding.
The mounting leg
152 defines an upper end
214 and a lower end
216.
The shape of the connecting plate
194 corresponds to the shape defined by
the inner face
190 and the outer face
192. The connecting plate
194
is rigidly and orthogonally attached to the inner face
190 and the outer
face
192, preferably by welding. The upper end
214 of the mounting
leg
152 thus narrows to a throat portion where the upper plate
198
is in close proximity to the outer face
192. A mounting flange
218
comprises a flat plate that is rigidly attached to the connecting plate
194
at the upper end
214 of the mounting leg
152 the mounting flange
218 is provided with apertures for attaching the mounting leg
152
to the frame of the vehicle with bolted connections as hereinafter described. Alternatively,
the flange
218 can be provided without apertures and welded to the frame
of the vehicle.
The upper link
154 is a generally flat, elongated member with a first
end
220 and a second end
222. The first end
220 is provided
with an aperture
224, and the second end
222 is provided with an
aperture
226. The lower link
156 is a generally flat, elongated member
with a first end
228 and a second end
230. The first end
228
is provided with an aperture
232, and the second end
230 is provided
with an aperture
234. Intermediate the two ends
228, k
230
of the lower link
156 a notch
236 is formed in the lower edge of
the link
156.
A reinforcing plate
238 comprises a generally flat piece of the same width
as the lower link
156. The reinforcing plate
238 is provided with
an aperture
240 of the same diameter as the aperture
232 in the lower
link
156 and the bar
206. In the preferred embodiment, the reinforcing
plat
238 is welded to the lower link
156 so that the apertures
232,
240 are in axial alignment.
A bumper bracket
244 is a generally T-shaped member comprised of a link
plate
246 and a bumper plate
248. The link plate
246 is orthogonal
to the bumper plate
248, and is attached to the bumper plate
248
by welding. The plates
246,
248 are provided with apertures to accommodate
conventional bolted connections by which he link plate
246 is connected
to the lower link
156 and the bumper plate
248 is attached to a bumper
insert
250. Alternatively, the bumper plate
248 can be attached to
the bumper insert
250 by welding.
A connecting bar
206 comprises a round bar for connecting and operating
the linkage assemblies as hereinafter described. Bar flanges
252 comprise
generally flat circular plates with an integral ear
254. The flanges
252
are provided with an aperture
256 to receive the bar
206. The ear
254 has an aperture
258 to receive a pin or bolt as hereinafter described.
The hydraulic power assembly comprises conventional hydraulic piston and cylinder
actuators
260, a conventional hydraulic power supply
262 comprising
a hydraulic fluid reservoir and actuator for controlling the delivery of hydraulic
fluid to the piston and cylinder actuators
260, a mounting bar
264,
and actuator covers
266. The hydraulic piston and cylinder actuators
260
comprise a cylinder portion
268, a piston rod
270 axially mounted
in the cylinder
268, a piston rod connector
272, and a mounting busing
274 connected to the end of the cylinder portion
268. In the preferred
embodiment, the hydraulic piston and cylinder actuators
260 are fluidly
connected to the hydraulic power supply
262 by hydraulic lines
269,
271 through conventional hydraulic fittings.
The mounting bar
264 is an elongated member with a square cross-section
suitable for fixedly mounting the hydraulic power supply
262 thereto. The
actuator covers
266 are generally irregularly-shaped planar members having
a peripheral lip
273 and mounting flanges
275. A notch
276
is formed in the lip
273 at the rear portion of the cover
266.
A cylinder clevis
278 is mounted to the interior surface of the actuator
cover
266 for mounting the actuators
260 to the covers
266.
The mounting busing
274 is pivotally connected to the cylinder clevis
278
such as by a conventional pinned or bolted connection. The piston rod
270
extends through the notch
276 and is operably connected to the bar flange
252 as hereinafter described. Mounting bar brackets
280 are provided
with square apertures
282 into which is inserted the mounting bar
264.
One mounting bar bracket
280 is fixedly attached, preferably by welding,
to each end of the mounting bar
264. One mounting bar bracket
280
is fixedly attached, preferably by welding, to each end of the mounting bar
264.
Each mounting bracket
280 is fixedly attached, preferably by welding to
a corresponding actuator cover
266. The hydraulic power supply
262
is rigidly attached to the mounting bar
264 midway between the two actuator
covers
266. The actuator covers
266, with attached piston and cylinder
actuators
260, and hydraulic power supply
262, are fixedly attached
to the underside of the vehicle by conventional welded or bolted connections.
Referring now to FIG. 8, the linkage assembly is assembled as follows.
The upper link
154 is pivotally attached to the vertical leg
150
by a conventional pin or bolt fastener passing through the apertures
167,
169 in the vertical leg and the aperture
226 in the upper link
154
is pivotally attached to the vertical leg
150 by a conventional pin or bolt
fastener passing through the apertures
167,
169 in the vertical leg
and the aperture
226 in the upper link
154. The upper link
154
is pivotally attached to the mounting leg
152 by a conventional pin or bolt
fastener passing through the apertures
208,
212 in the mounting leg
152 and the aperture
224 in the upper link
154. The lower
link
156 is pivotally attached to the vertical leg
150 by a conventional
pin or bolt fastener passing through the aperture
163 in the vertical leg
150 and the aperture
234 in the lower link
156.
The bearings
204 are inserted through the apertures
202,
210
in the mounting legs
152 and are fixedly retained therein, preferably by
welding. The connecting bar
206 is pivotally retained in the bearings
204
and rotates therein. The lower link
156 with attached reinforcing plate
238 is fixedly connected to the connecting bar
206 is pivotally retained
in the bearings
204 and rotates therein. The lower link
156 with
attached reinforcing plate
238 is fixedly connected to the connecting bar
206 adjacent to the mounting leg
152, preferably by welding. The
bar flanges
252 are fixedly mounted to each end of the connecting bar
206,
preferably by welding, adjacent to the lower link
156. The bar flanges
252
are spaced to accommodate the piston rod connector
272, which is pivotally
connected to the bar flanges
252 by a conventional pin or bolt connection
passing through the apertures
258 in the ears
254 and the piston
rod connector
272. Referring now to FIG. 14, the lower link
156 and
bar flanges
252 are connected to the connecting bar
206 so that when
the piston rod
270 is fully extended, and the ears
254 are at their
most rearward position, the lower link
156 will have rotated to its lowest
position, thus moving the liftgate/tailgate
8 to its lowest position.
The mounting legs
152 are mounted to the rear of the vehicle, such as
by welding or bolting the flanges
218 to the frame. A portion of the rear
of the vehicle, such as by welding or bolting the flanges
218 to the frame.
A portion of the rear bumper
120 corresponding to the linkage assemblies
148 is cut out to enable the mounting of the mounting legs
152. The
lower portion of each mounting leg
152 is also rigidly attached, preferably
by welding, to a corresponding actuator cover
266 along the rearward facing
lip of the cover
266. Referring now to FIG. 13, the mounting legs
152
are mounted to the rear of the vehicle through cutouts in the bumper
120
for this purpose. The bumper cover
250 are connected through the bumper
brackets
244 to the lower links
156 so that when the liftgate/tailgate
8 is in its fully raised position, the bumper covers
250 will be
positioned within the bumper cutouts to provide the appearance of an unbroken bumper.
Alternatively, it will be understood that the bumper could be provided
as a single unitary member without the separate covers
250 and simply be
mounted as a unit to the linkage assembly so that the bumper would move out of
obstruction of the movement of the tailgate with the movement of the linkage assembly.
Referring again to FIGS. 13 and 16, a tailgate retainer block
284
comprises a generally blocklike structure with an extension
286. The retainer
block
284 has a first side with a laterally extending channel
288
cut therein, and a second side with a circular passageway
290 extending
from the second side through the block to the channel
288. The passageway
290 is axially aligned with the aperture
188 in the locking tab
184
within the channel
288 when the liftgate/tailgate
8 is in its raised
closed position. A pin
292 is inserted into the circular passageway
290
and through the aperture
188 in the locking tab
184 to secure the
liftgate/tailgate
8 against vibration while the vehicle in motion.
The operation of the liftgate/tailgate will now be described with reference to
FIGS. 9-14. When the liftgate/tailgate
8 is in its upright and closed position,
the tailgate has the appearance of a conventional pickup trunk tailgate. The bumper
covers
250 are positioned within the bumper cutouts to provide the appearance
of an unbroken bumper surface. The tailgate may be operated in a conventional manner
to gain access to the bed of the vehicle. Referring specifically to FIG. 10, the
tailgate is retained in the open position by the cables
118 in a conventional
fashion. When it is desired to operate the lift gate, the pin is removed from the
retaining block
284, if necessary. Operating the controls to lower lift
gate will result in the piston rod
270 being extended toward the rear of
the vehicle. This will rotate the bar flanges
252 in a rearward direction
which will correspondingly rotate the lower link
156 in a rearward and downward
direction. At the same time, the upper link
154 will be rotated in a rearward
and downward direction, thus lowering the liftgate/tailgate
8. The length
of the upper and lower links
154,
156, and of the vertical leg
150n
and mounting leg
152, which form a parallelogram structure, maintains
the liftgate/tailgate
8 in a generally horizontal orientation during the
lifting and lowering operation.
When the liftgate/tailgate
8 is to be raised the controls will be actuated
to retract the piston rod
270, thus rotating the bar flanges
252
toward the front of the vehicle. The lower link
156 will be correspondingly
rotated in a forward and upward direction, thus raising the liftgate/tailgate
8.
When the liftgate/tailgate
8 has been returned to its fully raised position,
the pin can be replaced in the retaining block
284 and the tailgate returned
to a closed position. Referring the FIG. 15, the controls can be mounted within
a key fob
144 provided with control buttons
142 to actuate the hydraulic
power supply
262. Alternatively, conventional hydraulic controls (not shown)
can be provided.
Referring now to FIGS. 17-19, a second alternative embodiment liftgate/tailgate
309 of the invention will now be described. In this embodiment, as in the
first embodiment, both the assembly and the power supply are mounted to the upper
part of the vehicle and the liftgate. A similar structure, involving four legs
or links, is used. In this embodiment, however, the liftgate is operated by a cable
motor
314 and cable
316 operated with the power supply.
Referring now to FIG. 17, the alternative embodiment combination liftgate/tailgate
309 comprises the platform
10, one or more linkage assembly
312,
and a cable motor
314 and cable system.
Referring to FIG. 18, the linkage assembly
312 comprises a mounting
link
340, an upper link
342, a lower link
344, a vertical
link
346, and fasteners as hereinafter described. The mounting link
340
is an elongated member having a first end
350 and a second end
352.
The mounting link has a series of apertures
354,
356 for attaching
cable pulleys
362. The mounting link
340 also has a series of apertures
at positions
358, and
360 thereon in a spaced relationship along
the mounting link
340 intermediate the two ends
350,
352 thereof
for attaching the mounting link
340 to the sidewall
36 of the truck
bed
6 using fasteners (not shown).
The upper link
342 is an elongated member having first end
364
and a second end
366. The first and second ends
364 and
366
are provided with apertures (not shown) for pivotably mounting the upper link
342
to the vertical link
346 and the mounting link
340, respectively,
using fasteners, at positions
392 and
358 respectively.
The lower link
344 is a similar elongated member having a first end
376
and a second end
378. The lower link
344 is provided with a bend
380 intermediate the first and second end
376 and
378. The
first and second ends
376 and
378 are provided with apertures for
pivotably mounting the lower link to the vertical link
346 and the mounting
link
340 at position
360, using fasteners. The upper link
342,
the lower link
344, and the pulleys
362 may be alternatively mounted
directly to the sidewall
36, eliminating the mounting link
340.
The vertical link
346 is an elongated member having a first end
392
and a second end
394. An aperture is provided at the first end
392
for pivotably mounting the upper link
342 and pulley
364 using a
fastener. An aperture is also provided intermediate the first end
392 and
the second end
394 for pivotably mounting the lower link
344 using
a fastener. The vertical link
346 is also provided with an anchor
302
intermediate the ends
392 and
394 for attachment of the hydraulic
pistons
319, as a hereinafter described. The vertical link
346 also
comprises a telescoping portion
400 which incorporates one or more hollow
sleeves
402,
404,
406 that are graduated in size such that
the outside diameter of each sleeve is slightly smaller than the inside diameter
of the next sleeve, so that they can slide within each other. The innermost sleeve
406 can optionally be either hollow or solid. The bottom end of the innermost
sleeve
406 forms the second end
394 of the vertical link
346.
The second end
394 of the vertical link
346 has a pivotable fastener
or hinge
412 to which the tailgate
10 is mounted.
The upper link
342 and the lower link
344 are configured and attached
to the mounting link
340 and the vertical link
346 so that the inside
surface
20 remains parallel to the cargo bed
6 of the vehicle
2
throughout the lifting operation, and the liftgate/tailgate
309 can be closed
as a conventional tailgate. The fasteners may be fasteners as hereinbefore described
(e.g., fasteners
104,
106,
108, and
110).
The aforementioned attachments, pivotal mountings, and hydraulic pistons, cable
motor
314, and cable
316 will be dependent upon the magnitude of
the load to be lifted and the requirements that the upper link
342 and the
lower link
344 remain parallel to each other, that the platform
10
remain in a level position, during operation of the lift, and that the platform
10 not contact the vehicle bumper
120 or a trailer hitch (not shown)
as the platform
10 is raised and lowered
The cable
316 is mounted at its forward end to the cable motor
314
which, in turn, is mounted to the truck bed. The cable is also mounted, at the
rearward end, by any suitable means, as hereinbefore described, to the liftgate
309.
The operation of the liftgate
309 will now be described. When the liftgate/tailgate
9 is in the closed position, the upper link
342, the lower link
344,
and the vertical link
346 are brought into generally vertical alignment
with the mounting link
340, as shown in FIG. 19, and are enclosed by the
recess
43 of the platform
10. The liftgate/tailgate
309 can
be opened as a conventional tailgate by operating the tailgate latch
32,
which retracts the tailgate latch pins
38 from the slots in, optionally,
the truck bed or one or more of the linkages
312, which enables the liftgate/tailgate
9 to be rotated down and to the rear by pivoting about an axis defined by
the fastener
412. The rotation of the liftgate/tailgate
9 continues
until the tailgate support cables
318 are fully extended, and the tailgate
is held in the open tailgate position, preferably level with a floor surface of
the cargo bed
6. In the open tailgate position, the vertical link
346
is in a generally vertical orientation, parallel to the mounting link
340.
The upper link
342 and the lower link
344 remain in a generally vertical
position, generally parallel to each other.
When the liftgate/tailgate assembly
309 is to be operated as a liftgate
to move the platform
10 between the conventional open tailgate position
and a lowered position adjacent to the ground the cable motor
314 is operated
to extend cable
216 which is routed through pulleys
362,
364
on the mounting link and vertical link, respectively. Additional pulleys
414
mounted to the truck bed or chassis may also be used to route the cable. Extending
the cable will rotate the upper and lower links,
342 and
344, respectively
in a horizontal (rearward) direction, thus translating the vertical link
346
horizontally and, optionally, vertically, along with the liftgate/tailgate
8.
The length of the upper and lower links
342,
344, and of the vertical
link
346 and mounting link
340 (if present), which form a parallelogram
structure, maintains the liftgate/tailgate
8 in a generally horizontal orientation
during the lifting and lowering operation. The telescoping portion
400 of
the vertical link
346 is then actuated to extend the vertical link
346
and further lower the liftgate/tailgate
8 towards the ground while keeping
the platform
10 in a substantially horizontal plane. The fully extended
vertical link
346 in the liftgate lowered position is shown in FIG.
18.
When the liftgate/tailgate
8 is to be raised the controls will be actuated
to retract the cable, thus retracting first the telescoping portion
400
of the vertical link
346. Thus, once the telescoping portion
400
of the vertical link
346 is fully retracted, upper link
342 and lower
link
346 are rotated in a forward and upward direction, thus translating
the liftgate/tailgate
8 horizontally forward. When the liftgate/tailgate
8 has been returned to its fully raised and horizontally translated position,
the tailgate/liftgate can be returned to a closed position. The controls can be
mounted within a key fob
144 provided with control buttons
142 to
actuate the cable motor
314. Alternatively. conventional cable motor controls
(not shown) can be provided. Although the vertical links herein are described as
such, they need not be vertical per se, but can substantially vertical. I.e., they
can deviate by as much as 30 degrees from vertical as long as they maintain the
object to be lifted on the platform. Furthermore, the vertical link need only be
substantially vertical when the tailgate/liftgate is in the lowered position. Finally,
the entire link need not be vertical, but must have some substantially vertical
component when the tailgate/liftgate is in the lowered position, e.g., it can also
be L-shaped or J-shaped.
Referring now to FIGS. 20-22, a variation of the embodiment liftgate/tailgate
shown in FIGS. 7-11. In this embodiment, however, the liftgate is operated by a
hydraulic power supply and the bumper is a single unitary member, mounted as a
unit to the linkage assembly so that the bumper moves out of the way of the tailgate
and linkage assembly with the movement of the linkage assembly.
FIG. 20 shows the liftgate/tailgate in the closed position. In this position,
the rear of the liftgate/tailgate looks generally like a conventional pick-up truck
tailgate. Bumper
420 appears to be a single unitary bumper beam
422
and a step plate
424 mounted on top.
In this embodiment, the hydraulic power supply
262 rotates connecting
bar
206 which, in turn rotates both lower links
156 in a rearward and
downward direction. Linkages between vertical legs
150, lower links
156
and upper links
154 operate the same as described above in connection with
FIGS. 7-11 to lower
