Note: Descriptions are shown in the official language in which they were submitted.
o66668
Background of the Invention
This inventionrelates generally to lift devices and more par- ~
ticularly, but not by way of limitation, to a vehicle wheelchair lift for ~ -
raislng and lowering a wheelchair occupant.
Heretofore, there have been various types of wheelchair lifts
for mounting in a vehicle. The prior art lifts include both electrical
and hydraulic operated platforms. The lifts use a combination of cables,
gears, and pulleys for raising and lowering the wheelchair platform.
These types of systems are complex in design and the mechanical
arrangement of the cables, gears, and pulleys re~uire continual main-
tenance so that the lift is maintained in proper working order. Also,
some of the lifts re~uire overhead cross bars which are necessary to
provide the mechanical linkage for raising and lowering the wheelchair
platform. The cross bars limit the head room on entering and leaving ~-
the vehicle.
The subject inventlon provldes a novel wheelchair lift to aid in
the transportlng of the handlcapped.
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Summary of the Invention
The subject invention provides a power system for loading and
unloading the wheelchair platform from the vehicle and a separate power
system for lowering the platform to the ground surface.
The invention provides a vehicle wheelchair lift for loading and
unloading an occupant confined to a wheelchair, the lift being adapted for
mounting to a floor of a vehicle and adjacent an opening in the vehicle,
the lift comprising: a pair of stancion tubes to be disposed on each side
of the opening of the vehicle with the lower portion of the said tubes
attached to the floor of the vehicle; a pair of hydraulic cylinders mounted
inside a pair of hydraulic cylinder housings, the top of said housing
pivotally attached to the top of said stancion tubes; a pair of telescoping
channels slidably mounted in said hydraulic cylinder housings and attached
to the ends of said hydraulic cylinders; a lateral base channel horizontally
disposed and attached to the ends of said telescoping channels; a wheelchair
platform having one end pivotally attached to said lateral base channel; and
an electrically operated screw pivotally attached to one of said hydraulic
cylinder housings, the end of said screw releasably engaged to said platform;
in operation said screw lowering said platform outwardly from a vertical
position in the vehicle to a horizontal position for loading the wheelchair
thereon, said hydraulic cylinders lowering said platform downwardly to the
ground surface below the vehicle.
The sub~ect invention is rugged in construction and simple in design
and eliminates the use of cables, gears, and pulleys used in raising and
lowering the wheelchair platform.
The wheelchair lift preferably provides a novel cam linkage which
automatically pivots the hydraulic cylinders attached to the wheelchair plat-
form outwardly so that as the platform is lowered it clears the sides of
the vehicle below the door opening. The lift has no cross bars connecting
the hydraulic cylinders so that the head room is not limited when entering
and leaving the door opening of the vehicle.
~ The vehicle wheelchair lift is readily adaptable to any make of
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vehicle and includes an electric power supply system which may be powered
by the vehicle's battery.
The advantages and objects of the invention will become evident
from the following detailed description when read in conjuncti~n with the
accompanying drawings which illustrate the preferred embodiments of the
invention.
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Brief Description of the Drawings
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Figure 1 is a front view of the wheelchair lift vertically dis-
posed inside a door opening in the vehicle.
E~lgure 2 is a front view of the wheelchair lift with the wheel-
chair platform lowered horizontally for receiving the wheelchair from
the vehicle.
Figure 3 is a front view of the wheelchair lift with the wheel- ~ -
chair platform lowered horizontally to the ground surface.
~igure 4 is a side view of the wheelchair lift with the wheel-
chair platform in a vertical position inside the door opening in the
vehicle.
Figure 5 is a side view of the wheelchair lift with the wheel-
chair platform lowered to a horizontal position and adjacent the floor
of the vehicle.
Figure 6 is a side view of the wheelchair lift with the wheel-
chalr platform lowered to the ground surface.
Flgure 7 is a partial side view showing a detailed illustration
of the cam arrangement wlth the wheelchair platform in a vertical pos-
ltlon.
Flgure 8 is a partial side view showing a detailed illustration
of the cam arrangement with the wheelchair platform in a partially
lowered posltion.
Figure 9 is a partial side view showing a detailed illustration
of the cam arrangement with the wheelchair platform lowered to a hori-
zontal positlon adjacent the floor of the vehicle.
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Detailed Description of the Drawings
In Figure 1, the wheelchair lift is designated by general ref-
erence numeral 10. The lift 10 includes a frame 12 made up of a pair
of stanclon tubes 14 vertlcally mounted and disposed on both sides of
a door opening 16 of a vehicle 18. The stancion tubes 14 are attached
at the bottom to a base plate 20 which is secured to a floor 22 of the
vehicle 18. ~ -
Hydraulic cylinders, which are nat shown, are enclosed in
hydraulic cylinder housings 24. The housings 24 are pivotly attached
to the top of the stancion tubes 14. Telescoping channels 26 are slidably
mounted in the housing 24 and attached to the ends of the hydraulic :.
cylinders. The ends of the telescoping channels 26 are attached to a
horizontal lateral base channel 28.
A wheelchalr platform 30 is shown disposed in a vertical posl-
tlon in Plgure l. The platform 30 is made of a non-slip metal mesh
materlal 31 supported on metal braces 33. Hinge plates 32 are mounted
along the sldes of the platform 30 and are pivotly attached to the lateral :
.~ base channel 28 by hlnges 34. One of the hinge plates 30 includes
outwardly extendlng plns which are shown in detail in Figures 7 through
9. The plns attached to the hlnge plates 32 releasably engage a fold ~ . .
up cam 36 and a platform cam 38.
One end of the fold up cam 36 is pivotly attached to the end of
an electrlcally drlven screw 40. The screw 40 is drlven by a motor
- ln a screw houslng 42. The screw 40 and housing 42 are pivotly
attached to one of the cyllnder housings 24 by a hinge 44. The hinge 44 :
is shown in Figure 4. The other end of the fold up cam 36 is pivotly :
mounted to the cylinder houslngs 24 by a hinge 46.
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The hydraulic cylinders in the housings 24 and the electric
screw 40 are operated by a power supply pack 48 containing a hydraulic
pump, motor, electrical switches, and wiring. The power supply pack ~ ~ -
48 is connected to the battery of the vehicle 18.
S A bridge plate 50 is hinged at one end of the base plate 20 and
pivotly attached at the other end to the platform cam 38. The plate 50,
shown in Figure 1, is disposed in a vertical position. When the plat-
form 30 is lowered, the plate 50 in turn is lowered, thereby providing
a bridge between the floor 22 of the vehicle 18 and the platform 30 for
receiving the wheelchair thereon.
In Figure 2, the wheelchair lift 10 is l11ustrated with the platform
; 30 lowered by the screw 40 to a horizontal position adjacent the floor 22
of the vehicle 18. In this position, the wheelchair occupant is ready for
belng loaded onto the platform 30 from the vehicle 18.
lS In Figure 3, the wheelchair occupant who has been loaded onto
the platform 30 has now been lowered to a ground surface 52. The
platform 30 ls lowered to the ground surface 52 by the telescoping
channels 26 whlch are hydraullcally operated by the hydraullc cylinders
ln the hydraullc cyllnder housings 24.
In Figure 4, a side view of the lift frame 12 is illustrated show-
lng the platform 30 in a vertlcal posltlon inslde the vehlcle 18. This
vlew illustrates the platform 30 in the same posltlon as shown in
Figure 1. In this vlew, the compactness of the lift 10 is seen wherein
the houslngs 24 fold inwardly adjacent the stanclon tubes 14 with the
2S platf~rm 30 therebetween. The screw 40 is substantially parallel to
the housings 24 with the lower portion of the screw 40 plvotlng outwardly
as the screw 40 rotates the fold up cam 36 counter clockwise when
lowering the platform 30.
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In ~igure 5, a side view of the lift 10 is illustrated showing
the lift 10 in a similar position as shown in Figure 2. In this view,
the platform 30 can be seen horizontally positioned and adjacent the - -
floor 22 of the vehicle 18 with the bridge plate 50 lowered.
It should be noted that as the screw 40 lowers the platform 30,
the plvotly attached fold up cam 36 and platform cam 38 which are
pivotly attached to the hydraulic cylinder housings 24 pivot the lower
end of the cylinder housing 24 outwardly thereby providing clearance
between the platform 30 and the sides of the vehicle 18. -
Figure 6 is a side view of the lift 10 as illustrated in l~igure 3.
In th;ls view, the hinge plates 32 attached to the sides of the platform
30 have been released from the fold up cam 36 attached to the screw
40. The hydraulic cylinders in the hydraulic cylinder housings 24
have been activated and the telescoping channels 26 attached to the
lateral base channel 28 have in turn lowered the platform 30 to the
ground surface 52.
In l~igure 7, an enlarged view of the fold up cam 36 and the
platform cam 38 ls lllustrated. In thls vlew, the cams 36 and 38 can `
be seen releasably engaglng a fold up pin 54 and a bridge pin 56 which
are attached to and extend outwardly from the hinge plate 32.
In thls flgure, a line 58 is drawn through the length of the
electrlc screw 40 and connecting pin 60. The line 58 is offset from
the center of a connecting pin 62 which connects the cam 36 to the
hlnge 46. By offsetting the attachment of the screw 40 with the fold
up cam 36, the screw 40 pivots the fold up cam 36 outwardly. At
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is time, the fold up cam 36 engages pin 54 thereby unfolding the
- platform 30 outwardly and down~vardly from the vehicle 18. As the
platform 30 moves outwardly, the pin 56 engages the platform cam 38
which is pivotly attached to a bridge bracket 64 which includes a
hanger 66 for lowering the bridge plate 50.
In ~igure 8, the platform 30 has been partially lowered and
the cams 36 and 38 are still engaged to pins 54 and 56. In this view,
it can be seen by the combination of the pivoting of the cams 36 and
38, the cylinder housings 24 are urged outwardly from the vertically
mounted stancion tubes 14.
In Figure 9, the platform 30 has been lowered to a horizontal
posltion by the screw 40 and the pins 54 and 56 are disengaged from
the cams 36 and 38. Also, the bridge plate 50 has been lowered to
a posltion adjacent the length of the lateral base channel 28. The
platform 30 is now in position for being lowered to the ground surface
52 by the telescoping channels 26.
When lt is desired to retract the platform 30 into the vehicle
18, the platform 30 Is ralsed to a horizontal position adjacent the floor
22 of the vehlcle. The wheelchalr occupant is wheeled into the vehicle
across the lateral base channel 28, the bridge plate 50, and onto the
vehlcle floor 22. The screw 40 is then fed upwardly. As the screw
40 ralses, the cams 36 and 38 engage the pins 54 and 56. The cam
36 folds the platform 30 upwardly and inwardly into the vehicle 18.
At the same time, the platform cam 38, via the bridge bracket 64,
ralses the bridge plate 50 upwardly. When the screw 40 has completed
lts travel upwardly, the platform 30 and hydraulic cylinder housings
24 are retracted into a vertical position inside the vehicle 18.
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Changes may be made in the construction and arrangement of
the parts or elements of the embodiments as disclosed herein without .-
departing from the spirit or scope of the invention as defined in the
following claims.
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