U.S. patent number RE28,455 [Application Number 04/385,078] was granted by the patent office on 1975-07-01 for portable elevator working and load-lifting platform.
This patent grant is currently assigned to Howard H. Denier. Invention is credited to Dennis J. Denier, Howard H. Denier, Lee R. Garrett, Thomas Hedger.
United States Patent |
RE28,455 |
Denier , et al. |
July 1, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Portable elevator working and load-lifting platform
Abstract
The invention teaches the use of a hydraulic system having
primary ram booster means to start the raising of a platform
coacting with other ram means to raise and lower the platforms. The
platform is raised and lowered by remote control by a workman on
the platform and it also can be raised and lowered by any one not
on the platform. It utilizes a vehicle for the platform having a
usual controlled rectified electric circuit for a motorized driving
means for the vehicle that prevents the drive motor attaining
maximum speed when the platform is slightly raised above the
chassis and permits the drive motor to attain maximum speed when
the platform is completely collapsed down on the chassis. It is
steered while in motion in any desired direction, hydraulically
under remote control by the workman while the platform is at either
its lowest or uppermost position.
Inventors: |
Denier; Howard H. (Cincinnati,
OH), Denier; Dennis J. (Cincinnati, OH), Hedger;
Thomas (Cincinnati, OH), Garrett; Lee R. (Hamilton,
OH) |
Assignee: |
Denier; Howard H. (Cincinnati,
OH)
|
Family
ID: |
27010882 |
Appl.
No.: |
04/385,078 |
Filed: |
August 2, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
872542 |
Oct 30, 1969 |
03596735 |
Aug 3, 1971 |
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Current U.S.
Class: |
182/16; 182/148;
182/69.5 |
Current CPC
Class: |
B66F
11/042 (20130101); E04G 1/22 (20130101); B66F
3/22 (20130101) |
Current International
Class: |
B66F
3/22 (20060101); B66F 3/00 (20060101); B66F
11/04 (20060101); E04G 1/18 (20060101); E04G
1/22 (20060101); E04g 001/22 () |
Field of
Search: |
;182/12,13,16,17,63,141,148 ;91/459 ;321/45C ;254/122 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Machado; Reinoldo P.
Attorney, Agent or Firm: Wood, Herron & Evans
Claims
Having described our invention we claim:
1. A lifting vehicle comprising:
a base member resting upon the ground and movable in a horizontal
path;
a vertically movable platform disposed above said base member;
a compound lever system interconnecting the base member and
platform operable in scissors fashion for raising and lowering the
platform vertically relative to the base member at a selected
horizontal location;
said compound lever system comprising a plurality of bar members
pivotally connected together at the central portion thereof and
having ends pivotally connected together;
said lever system having a lower bar member pivotally connected to
the base member and having a companion lower bar member connected
to the base member for longitudinal motion relative thereto, during
the extending or collapsing motion of the compound lever
system;
said compound lever system having an upper bar member pivotally
connected to the said platform for pivotal movement and having a
companion upper bar member connected to the platform for
longitudinal motion relative to the platform during the extending
or collapsing movement of the compound lever system;
upright rotatable primary power elements mounted on the base member
and each having ram elements engageable with concave sockets
supported on a portion of the lower companion bars of the compound
lever system when the lever system is in the said collapsed
position, thereby to provide a direct thrust for shifting the lever
system initially from said collapsed position to a partially
erected position;
a horizontal shaft extending transversely across the base member,
said primary power elements having lower ends connected and secured
to said shaft for pivotal motion of the power elements;
and a plurality of paired secondary power elements normally
disposed at an acute angle to the base member for erecting the
companion bars of the lever system from the said partially erected
position;
a pair of said secondary power elements having lower ends pivotally
connected to the lower ends of said bar members pivotally connected
to said base member and having a ram pivotally connected to an
intermediate portion of the compound lever system;
said paired secondary power elements to pivot from said acute angle
toward an upright position and to extend the compound lever system
to a predetermined height after the primary booster power elements
have initially shifted the same from said collapsed position
thereby to elevate said platform.
2. A lifting vehicle as set forth in claim 1 in which there is
provided a pair of outrigger elements pivotally connected to
opposite sides of the base member having swiveled wheels engageable
with the ground for stabilizing the base member and platform when
the platform is in said elevated position while stationary and in
motion and respective hydraulic power elements interconnecting the
outriggers with the vehicle chassis for raising or lowering the
outriggers.
3. A lifting vehicle as set forth in claim 1 in which the primary
booster power element and the secondary power element comprise
hydraulic cylinders;
a hydraulic pressure system interconnecting the said cylinders and
having a valve element for supplying and exhausting hydraulic
pressure relative to the said cylinders for raising and lowering
the platform.
4. A lifting vehicle as set forth in claim 1 in which the primary
booster power element and the secondary power element comprise
hydraulic cylinders;
a hydraulic pressure system connected with said cylinders in
common;
said hydraulic system having a valve element for supplying
hydraulic pressure to said booster cylinder and secondary cylinder
simultaneously, and;
the ram element of said booster cylinder providing a substantially
initial greater thrust than the ram of the secondary cylinders but
providing a shorter working stroke, and;
the rams of thee secondary cylinders being effective to continuing
the extending of the compound lever system to said predetermined
height after the ram of the booster cylinder has reached the end of
said working stroke.
5. A self-propelled lifting .Iadd.apparatus .Iaddend..[.vehicle.].
comprising:
a wheeled vehicle having a set of wheels including dirigible wheels
for guiding the horizontal path of motion of the vehicle;
a power motor on said vehicle for driving the said wheels thereby
to move the vehicle in a horizontal path;
control means for regulating the operation of the power motor of
the vehicle;
power means connected to said dirigible wheels for guiding the
vehicle;
a vertically movable platform disposed above the vehicle;
a pair of extensible lazy tongs connecting the vehicle and platform
for raising and lowering the platform vertically relative to the
vehicle at a selected horizontal location;
each lazy tong having pairs of intermediate bars pivotally
connected together at the central portion thereof and the bars
having outer ends pivotally connected together and constituting
frames;
said lazy tongs having a lower frame, the bars of which have one
end pivotally connected to the vehicle at opposite sides and an
opposite end shiftably connected to the vehicle at opposite sides
for longitudinal motion relative to the vehicle during the
extending or collapsing motion of the lazy tongs frames;
said lazy tongs having an upper frame, the bars of which have one
end pivotally connected to the said platform at opposite sides and
having an opposite end shiftably connected to the platform at
opposite sides for longitudinal motion relative to the platform for
extending or collapsing movement of the lazy tongs frames;
a pair of primary power elements mounted on the vehicle, each
having a thrust element engagable with the said lower frame of the
lazy tongs when the frame is in a collapsed position, thereby to
provide a direct thrust for shifting the lazy tongs initially from
said collapsed position to a partially erected position;
a first pair of secondary power elements having lower ends
pivotally .Iadd.mounted to react in opposition
.Iaddend..[.connected.]. to the .Iadd.vehicle
.Iaddend..[.chassis.]. and having extensible thrust elements
pivotally connected to one of said intermediate lazy tongs
frames;
and a second pair of secondary power elements having lower ends
pivotally connected to one of said intermediate lazy tongs frames
and having thrust elements pivotally .Iadd.mounted to react in
opposition .Iaddend..[.connected.]. to said platform;
said secondary power elements operable to extend the said lazy
tongs frames to a predetermined height after the primary power
elements have initially lifted the frames from said collapsed
position, thereby to elevate the platform.
6. A lifting vehicle as set forth in claim 5 in which the frames of
the lazy tongs each comprise duplicate pairs of levers and in which
there is provided crossmembers extending across the pivoted outer
ends of the bars which constitute the lazy tongs frames to
stabilize the lazy tongs.
7. A lifting vehicle as set forth in claim 5 in which the frames of
the lazy tongs each comprise duplicate pairs of levers and in which
there is provided crossmembers extending across the pivoted outer
ends of the bars which constitute the lazy tongs frames to
stabilize the lazy tongs;
said vehicle having a pair of inwardly facing channel members at
opposite sides thereof, the ends of the bars of the lower frame,
which are shiftably connected to the vehicle having roller elements
on said crossmembers;
said rollers interfitted within said channels for longitudinal
movement thereof relative to the vehicle as the lazy tongs frames
are extended or collapsed.
8. A self-propelled lifting vehicle as set forth in claim 5 in
which the power means which is connected to said dirigible wheels
for guiding the vehicle comprises a hydraulic cylinder connected to
the vehicle and having a piston including a piston rod connected to
the dirigible wheels, a hydraulic pressure system, and a control
valve connected to the cylinder for admitting and exhausting
hydraulic pressure relative to the opposite ends of the
cylinder.
9. A self-propelled lifting .Iadd.apparatus .Iaddend..[.vehicle.].
comprising:
a wheeled vehciel having .Iadd.a chassis and .Iaddend.a set of
wheels for guiding the horizontal path of motion of the
vehicle;
a drive motor on said chassis for driving the said wheels thereby
to propel the chassis in a horizontal path;
a control for said motor for regulating the motion of the
vehicle;
a hydraulic steering cylinder having a piston rod connected to said
dirigible wheels for guiding the vehicle;
a vertically movable platform disposed above the vehicle;
a pair of extensible lazy tongs connecting the vehicle and platform
for raising and lowering the platform vertically relative to the
chassis at a selected horizontal location;
said lazy tongs having pairs of intermediate bars pivotally
connected together at the central portion thereof, the bars having
outer ends pivotally connected together and constituting
frames;
said lazy tongs having a lower frame, the bars of which have one
end pivotally connected to the vehicle at opposite sides, and an
opposite end shiftably connected to the vehicle at opposite sides
for longitudinal motion relative thereto for extending or
collapsing the lazy tongs;
said lazy tongs having an upper frame, the bars of which have one
end pivotally connected to the said platform at opposite sides for
pivotal movement and having an opposite end shiftably connected to
the platform for extending or collapsing movement of the lazy
tongs;
a pair of primary booster cylinders mounted on the chassis, each
having a ram element engagable with the lower frame of the lazy
tongs when the lower frame is in the said collapsed position,
thereby to provide a direct thrust for shifting the lower lazy
tongs frame initially from said collapsed position to a partially
erected position;
a first pair of secondary cylinders having their lower ends
pivotally connected to the .Iadd.lower frame .Iaddend..[.chassis.].
and having a ram pivotally connected to one of said intermediate
lazy tongs frames;
a second pair of secondary cylinders having their lower ends
pivotally connected to said intermediate lazy tongs frames and
their rams pivotally connected to said .Iadd.upper frame
.Iaddend..[.platform.].;
said secondary cylinders operable to extend the said frames to a
predetermined height after the primary booster cylinder has
initially lifted the frames from said collapsed position, thereby
to elevate the platform;
a hydraulic pressure system for supplying and exhausting hydraulic
pressure relative to the several hydraulic cylinders;
and an electrical control system including electrically operated
valves for controlling the said hydraulic system, thereby to
regulate the operation of the self-propelled lifting vehicle and
platform.
10. A self-propelled lifting vehicle as set forth in claim 9 in
which there is provided a source of electrical energy, a drive
motor mechanically interconnected with the wheels of the vehicle
for driving the same, a shiftable steering lever electrically
interconnecting the drive motor with the electrical energy, said
lever being shiftable from a neutral position to a forward or
reverse position and thereby energizing the motor in forward or
reverse directions in response to the direction of movement of the
shiftable steering lever.
11. A self-propelled lifting vehicle as set forth in claim 9 in
which there is provided a source of electrical energy, a drive
motor mechanically interconnected with the wheels of the vehicle
for driving the same, a shiftable steering lever electrically
interconnecting the drive motor with the electrical energy, said
lever being shiftable from a neutral position to a forward or
reverse position and thereby energizing the motor in forward or
reverse direction in response to the direction of movement of the
shiftable steering lever;
an electrically operated brake in operative connection with the
said drive motor, and an electrical switch interconnecting the said
electrical energy and electrically operated brake for applying the
brake to hold the vehicle and platform in a stationary
position.
12. A self-propelled lifting vehicle as set forth in claim 9 in
which there is provided a source of electrical energy, said
operated drive motor mechanically interconnected with the wheels of
the vehicle for driving the same, a shiftable lever interconnecting
the drive motor with the source of electrical energy for driving
the motor in forward or reverse directions, said hydraulic control
system having an electrically operated valve for regulating the
operation of the steering cylinder, said electrical control circuit
including sets of steering contacts interconnected with the
electrically operated valve, and a second shiftable lever for
alternately closing said steering contacts for energizing the valve
and admitting hydraulic pressure to the steerin cylinder in forward
or reverse direction for guiding the path of motion of the
vehicle.
13. A self-propelled lifting vehicle as set forth in claim 9 in
which there is provided a source of electrical energy, said
operated drive motor mechanically interconnected with the wheels of
the vehicle for driving the same;
a shiftable lever interconnecting the drive motor with the source
of electrical energy for energizing the motor in forward or reverse
directions, said electrical control circuit including a directional
steering lever interconnected with the electrically operated valve
of the steering cylinder for admitting hydraulic pressure to the
cylinder in forward or reverse direction for guiding the path of
motion of the vehicle;
said steering lever guiding the vehicle in a direction
corresponding to the direction of movement of the steering
lever;
said steering lever having a neutral position in which the
electrically operated valve shifts the steering cylinder to a
neutral position for guiding the vehicle in a straight path of
motion.
14. A self-propelled lifting vehicle as set forth in claim 9 in
which there is provided a limit switch mounted relative to the
vehicle and platform, said limit switch having contacts
interconnected with the electrical control circuit and actuated by
the platform, said contacts retarding the speed of operation of the
drive motor when the platform is in its raised position.
15. A self-propelled lifting vehicle as set forth in claim 9 in
which there is provided a limit switch mounted relative to the
vehicle chassis and platform, said limit switch having contacts
interconnected with the electrical control circuit and actuated by
the platform in the lowered position thereof;
a source of electrical energy for the said drive motor which
propels the vehicle;
means interconnecting the drive motor and source of electrical
energy for energizing the motor in forward or reverse directions or
for deenergizing the motor;
said electrical control circuit having control means interposed in
the source of electrical energy for regulating the speed of the
drive motor;
said limit switch coacting with the control means to retard the
speed of operation of the drive motor when the platform is raised
slightly from the lowest collapsed position.
16. A self-propelled lifting vehicle as set forth in claim 9 in
which the hydraulic control system includes electrically operated
hydraulic valves and in which the electrical control system
includes switches electrically interconnected with the respective
electrically operated valves, said valves interconnecting the
hydraulic control system respectively with the said hydraulic
primary booster cylinder, the hydraulic secondary cylinders of the
intermediate lazy tongs frames for raising and lowering the
platform.
17. A self-propelled lifting vehicle as set forth in claim 9 in
which the hydraulic control system includes electrically operated
hydraulic valves and in which the electrical control system
includes switches electrically interconnected with the respective
electrically operated valves, said valves interconnecting the
hydraulic control system respectively with the said hydraulic
primary booster cylinder, the hydraulic secondary cylinders of the
intermediate lazy tongs frames for raising and lowering the
platform;
said hydraulic system including means for hydraulically locking the
rams of said cylinders for supporting the platform at a selected
elevation.
18. A self-propelled lifting vehicle as set forth in claim 9 in
which the hydraulic system includes electrically operated hydraulic
valves and in which the electrical control system includes switches
electrically interconnected with the respective electrically
operated valves;
said valves interconnecting the hydraulic control system with said
hydraulic primary booster cylinders and the hydraulic secondary
cylinders for raising and lowering the platform upon operation of
the switches;
said electrical control system including an electrical control
device for regulating the supply of hydraulic pressure to the
steering cylinder for controlling the direction of motion of the
vehicle chassis and its platform with the platform in its raised or
lowered position.
19. A self-propelled lifting vehicle as set forth in claim 9 in
which the hydraulic system includes electrically operated hydraulic
valves and in which the electrical control system includes switches
electrically interconnected with the respective electrically
operated valves;
said valves interconnecting the hydraulic control system with the
said hydraulic primary booster cylinders and the hydraulic
secondary cylinders for raising and lowering the platform upon
operation of the switches;
said electrical control system including an electrical switch for
regulating the supply of hydraulic pressure to the steering
cylinder for controlling the direction of motion of the vehicle
chassis and its platform with the platform in its raised or lowered
position;
said hydraulic system having a motor driven hydraulic pump;
said electrical control system arranged to energize the motor of
said hydraulic pump to provide hydraulic pressure when any one of
said electrical switches are closed.
20. A self-propelled lifting vehicle as set forth in claim 9 in
which there is provided a pair of outriggers pivotally connected to
the opposite sides to the vehicle and engageable with the ground,
respective hydraulic cylinders for raising or lowering the
outriggers, the hydraulic control system having electrically
operated hydraulic valves and the electrical control system having
switches electrically interconnecting with the respective
electrically operated hydraulic valves;
said valves interconnecting the hydraulic control system
respectively with said hydraulic outrigger cylinders for raising
and lowering the outriggers selectively.
21. A self-propelled lifting vehicle as set forth in claim 9 in
which each primary booster cylinder is mounted relative to the
platform and vehicle and includes an outwardly projecting ram, the
outer end of said ram having a thrust element mounted thereon,
coacting element arranged for engagement by the thrust element of
the ram when the ram of the booster cylinder is extended, thereby
initially lift the platform from the lowered position thereof to a
predetermined elevation, said coacting thrust elements providing
disengagement there between when the secondary cylinders of the
intermediate lazy tongs frames lift the platform toward said
predetermined elevation.
22. A self-propelled lifting vehicle as set forth in claim 9 in
which each primary booster cylinder is mounted upon the vehicle and
includes an upwardly projecting ram, the upper end of said ram
having ball element mounted thereon, one of said lazy tongs frames
having a socket element arranged for thrust engagement by the ball
elements of the ram when the ram of the booster cylinder is
elevated, thereby to initially lift the platform from the lowered
position thereof to a predetermined elevation, said ball and socket
elements providing disengagement there between when the secondary
cylinders of the intermediate lazy tongs frames lift the platform
toward said predetermined elevation.
23. A self-propelled lifting vehicle as set forth in claim 9 in
which each primary booster cylinder is pivotally mounted upon the
vehicle and includes stop means for holding the cylinder in an
upright position;
an upwardly projecting ram, the upper end of said ram having a ball
element mounted thereon;
one of said lazy tongs frames having a socket element arranged for
thrust engagement by the ball element of the ram when the ram of
the booster cylinder is elevated, thereby to initially lift the
platform from the lowered position thereof toward a predetermined
elevation;
said pivotally mounted booster cylinder pivoting in an arc in
response to the arcuate motion of the lazy tongs frames as the
frames lift the platform from said collapsed position toward said
predetermined elevation;
spring means providing said pivotal motion of the booster
cylinder;
said spring means pivoting the booster cylinder back to said
upright position against the stop means upon disengagement of the
said ball element from the socket element as the secondary
cylinders elevate the platform toward the said predetermined
elevation.
24. A self-propelled lifting vehicle as set forth in claim 9 in
which the vehicle is propelled by banks of electrical storage
batteries;
said batteries being interconnected with the drive motor for
propelling the vehicle and also being interconnected with the
electrical control circuit for energizing the same;
said batteries being mounted upon the vehicle, whereby the weight
load of the storage batteries act as a ballast to stabilize the
vehicle when the said platform is in its elevated position.
.Iadd.25. A self-propelled lifting vehicle including a chassis, a
set of wheels on the chassis to permit movement along a horizontal
path of motion, a power motor on the vehicle chassis to power the
vehicle along the path of motion, power means connected to the
vehicle wheels for guiding the vehicle along the path of motion,
wherein the improvement comprises:
a vertically movable platform assembly disposed above the vehicle
chassis;
control means for regulating the operation of the power motor and
the power means, said control means being disposed on said
vertically movable platform and operable to regulate the power
motor and the power means even while the platform is elevated above
the vehicle chassis;
a pair of extensible lazy tongs interconnecting the vehicle and
said platform for raising and lowering said platform vertically
relative to said vehicle chassis, each lazy tong including pairs of
bars pivotally connected together at the central portion thereof,
each said pair of pivotally connected bars comprising a frame, said
lazy tongs each having at least two frames;
a primary power element mounted on the vehicle chassis and
controllable from said platform, said primary power element having
a thrust element engagable with said tongs at a position
intermediate the connection between said tongs and said vehicle
chassis and the connection point between said tongs and said
platform, said primary power element being engagable with said
tongs when said tongs are in a collapsed condition thereby to
provide a direct thrust for shifting the tongs from a collapsed
position where said platform is adjacent the chassis to a partially
erected position where said platform is elevated above the
chassis;
a secondary power element controllable from said platform and
pivotally connected at its lowermost end to one said frame of said
lazy tongs and pivotally connected at the upper end of said
secondary power element to another frame disposed above said one
frame, said secondary power element being operative to extend said
tongs from said partially erect position to
further elevate said platform. .Iaddend. 26. The lifting vehicle as
set forth in claim .[.27 or 28.]. .Iadd. 25 .Iaddend.wherein
.[.each lazy tong comprises pairs of bars pivotally connected
together at the central portion thereof and.]. said secondary power
.[.means.]. .Iadd. element .Iaddend.comprises a pair of power
elements having the lower end of each power element pivotally
attached to a bar of said tongs at a point substantially adjacent
the connection between said tongs and said vehicle chassis. .Iadd.
27. The lifting vehicle as set forth in claim 25 wherein said
control means includes means to reduce the maximum speed obtainable
by the power motor when said platform is disposed above the vehicle
chassis. 28. The lifting vehicle as set forth in claim 25 wherein
said platform includes a section secured to the platform for
increasing the platform working area when disposed in co-planar
relation with said platform. 29. The lifting vehicle as set forth
in claim 25 wherein the primary power element is pivotally mounted
on the vehicle chassis thereby providing a greater height above the
vehicle chassis for said partially erected position. 30. The
lifting vehicle as set forth in claim 25 wherein the control means
includes a silicon controlled rectifier for controlling the power
motor. 31. The lifting vehicle as set forth in claim 25
additionally including a pair of outriggers pivotally connected to
opposite sides of the chassis, each said outrigger being vertically
movable between a ground contacting position and a non-contacting
position, the vertical movement of said outriggers being
controllable from said platform. 32. A self-propelled lifting
vehicle including a chassis, a set of wheels on the chassis to
permit movement along a horizontal path of motion, a power motor on
the vehicle chassis to power the vehicle along the path of motion,
power means connected to the vehicle wheels for guiding the vehicle
along the path of motion, wherein the improvement comprises:
a vertically movable platform disposed above the vehicle
chassis;
control means for regulating the operation of the power motor, said
control means being disposed on said vertically movable
platform;
a pair of extensible lazy tongs connecting the vehicle and the
platform for raising and lowering the platform vertically relative
to the vehicle chassis;
each lazy tong having a plurality of pairs of bars pivotally
connected together at the central portion thereof and constituting
frames;
the vehicle chassis, said tongs and said platform comprising a
lifting assembly;
a primary power element mounted on the vehicle and controllable
from said platform, said power element having a thrust element
engagable with said tongs when the tongs are in a collapsed
position thereby to provide a direct thrust for shifting the tongs
from said collapsed position to a partially erected position;
a first secondary power means having its lower end pivotally
attached substantially to the lower end of said lifting assembly
and its upper end pivotally attached to said tongs at a point
intermediate said vehicle chassis and said platform; and
a second secondary power means having its lower end pivotally
connected to said tongs at a point intermediate said vehicle
chassis and said platform and its upper end pivotally attached to
the upper end of said lifting assembly thereby to provide with said
first and said second secondary power means the thrust for shifting
the tongs from said partially erected position to a fully erected
position, said first and second secondary
power means being controllable from said platform. 33. A
self-propelled lifting vehicle including a chassis, a set of wheels
on the chassis to permit movement along a horizontal path of
motion, a power motor on the vehicle chassis to power the vehicle
along the path of motion, power means connected to the vehicle
wheels for guiding the vehicle along the path of motion, wherein
the improvement comprises:
a vertically movable platform disposed above the vehicle
chassis;
control means for regulating the operation of the power motor, said
control means being disposed on said vertically movable platform
and operable to regulate the power motor even when the platform is
disposed above the vehicle chassis;
a pair of extensible lazy tongs connecting the chassis and the
platform for raising and lowering the platform vertically relative
to the chassis;
each lazy tong having pairs of bars pivotally connected together at
the central portion thereof and the bars having outer ends
pivotally connected together and constituting frames;
said lazy tongs having a lower frame, the bars of which have one
end pivotally connected to the chassis at opposite sides and an
opposite end shiftably connected to the chassis at opposite sides
for longitudinal motion relative to the chassis during extending or
collapsing motion or the lazy tongs;
said lazy tongs having an upper frame, the bars of which have one
end pivotally connected to said platform at opposite sides and
having an opposite end shiftably connected to the platform at
opposite sides for longitudinal motion relative to the platform
during extending or collapsing movement of the lazy tongs;
a pair of primary power elements mounted on the chassis and
controllable from said platform, each having a thrust element
engagable with said lower frame of the lazy tongs when the tongs
are in a collapsed condition thereby to provide a direct thrust for
shifting the lazy tongs initially from the collapsed to a partially
erected position;
a first pair of secondary power elements having lower ends
pivotally connected to said lower frame at a point substantially
adjacent the connection between said lower frame and the vehicle
chassis and having extensible thrust elements pivotally connected
to another of said frames;
a second pair of secondary power elements having lower ends
pivotally connected to a frame other than said upper frame and
having thrust elements pivotally connected to said upper frame at a
point substantially adjacent the connection between said upper
frame and said platform;
said secondary power elements being controllable from said platform
and operable to extend said lazy tongs to a predetermined height
after the primary power elements have initially lifted the tongs to
said partially erected position..Iaddend.
Description
It is an object of the invention to provide a platform for workmen
that can be raised and lowered and held hydraulically at any height
in beween the upper and lowest limits of the elevating mechanism by
remote pushbutton control by the workmen on the platform.
It is an object of our invention to provide a primary hydraulically
actuated means to initially start the raising of the platform to an
opportune height and continue the raising of the platform by
coaction of a secondary bydraulically actuated elevating means.
It is the object of the invention to provide a silicon-controlled
rectified electric circuit, for the motorized driving means, that
is remotely controlled by the workmen on the platform whereby the
speed of travel of the platform is gradually accelerated and/or
deaccelerated to a desirable gradual movement in either direction
and travel, speed, braking or plugging and directional change are
accomplished by a single control lever for any direction of
movement of the platform.
It is another object of our invention to provide a movable
stabilizing hydraulic outrigger means to secure the platform in
vertical nontilting position while in stationary position and while
in motion from place to place while platform is in the highest or
lowest elevated position.
Another object is to control the speed of travel of the platform
when it is raised slightly above its chassis and/or in its highest
elevation.
These and other objects will become apparent from the description
and the drawings illustrating the preferred embodiment of our
invention.
IN THE DRAWINGS
FIG. 1 is a side view in elevation showing the platform with its
extension and the elevating mechanism in its lowest collapsed
position.
FIG. 2 is a top plan view FIG. 1 showing an extension for the
platform folded back.
FIG. 3 is an end view in elevation showing the platform at its
lowest level and the elevating mechanism in collapsed position.
FIG. 4 is a fragmented top plan view of one of the stabilizing
outriggers.
FIG. 5 is a fragmented side view in elevation of one of the
stabilizing outriggers.
FIG. 6 is an end view in elevation showing the platform at its
highest level with the stabilizing outriggers down in position to
prevent tilting of the platform.
FIG. 7 is a side view in elevation showing a platform at its
highest level with the stabilizing outriggers down in position to
prevent the tilting of the platform.
FIG. 8 is a top plan view of our carriage for the platform taken on
line 8--8 of FIG. 6.
FIG. 9 is a side view in section taken on line 9--9 of FIG. 8 with
a fragment of the lazy tongs.
FIG. 10 is a fragmentary view in elevation of a hydraulic booster
ram.
FIG. 11 is a front view in elevation of the pushbutton control
panel.
FIG. 12 is a section through a chassis of the carriage taken on
line 12--12 of FIGS. 7, 8 and 9 showing the hydraulic pump,
reservoir and manifold.
FIG. 13 is a typical sectional view taken on line 13--13 of FIGS.
7, 8 and 9 showing the bearing the channels on the chassis and
underside of the platform.
FIG. 14 is a fragmentary view of a typical sectional view showing a
typical joint on the lazy arms.
FIG. 15 is a diagrammatic illustration of a hydraulic system for
elevating and lowering the platform with electric wiring leads
shown in part to and from the electronically operated solenoid
valves.
FIG. 16 is a diagram of electric wiring for energizing a hydraulic
pump motor that drives a pump for circulating hydraulic fluid,
together with the silicon-controlled rectifier for the motor
driving the vehicle.
In the preferred form our portable elevator platform has a chasses
frame 1 for a vehicle formed from structural shapes that is movably
supported on rubber-tired drive wheels. Wheels 2 of the vehicle are
driven by a drive motor 3 directly connected to a differential gear
drive and housing 4 fixed on the chassis (see FIG. 8). An
electromagnetic safety brake is attached to the drive to hold the
vehicle stationary. The acceleration or the deacceleration of
movement of the platform is controlled electrically (to be
explained) so that starting and/or stopping of the motor drive is
gradual thereby preventing any jerking motion during starting or
stopping the movement of our portable elevator platform. Other
rubber-tired steering wheels 5 for the vehicle are dirigible and
are pivoted on pivot kingpins 6 and provide the means for steering
the platform. The kingpins are connected together by a spanner bar
to prevent the wheels from tilting out of a vertical plane. The
pivot kingpins 6 are connected to a front axle 6a (see FIG. 8).
Cranks 7 secured to the front axle are connected together by a tie
rod 8 that is pivotally connected to the cranks on pins 9 that are
fixed in a bifurcated link 10. Pivotally connected to the tie rod
there is a piston rod 11 that is actuated by a hydraulic steering
cylinder 12. When the piston rod moves to the left the vehicle will
steer to the right and when it moves to the right the vehicle will
steer to the left. This cylinder is pivotally secured on a pin 13
that is secured on a bracket 14 that in turn is fixed on the
chassis frame 1 of the vehicle. Hydraulic hose lines 15 and 15b to
the steering cylinder are connected to a solenoid-actuated four-way
valve 15a, to be explained (see FIG. 16).
A platform 16 for workmen and materials with guard rails 17 is
raised and lowered by collapsible and expandable by a compound
lever system or lazy tongs frames 18 composed of a multiple of bars
12 which operate in scissor fashion. Bars 19 are pivotal connected
at their ends by pins 20 and other pins 21 at their centers to form
lazy tongs. Fixed in the chassis there are bearings 22 for studs 23
upon which lower ends 24 of the bars are rotatably supported. These
ends of the lazy tongs do not move in relation to the chassis.
Other pins 25 are fixed in a base 26 of the platform and rotatably
secure upper ends 27 of bars 19 of the lazy tongs to the platform.
These ends do not move in relation to the platform. Secured in the
bottom ends 19a of the bars 19 there are shafts 28 (see FIG. 13)
upon which inner races 29 of roller bearings 30 are fixed.
Rotatable outer races 31 of the roller bearings rotate on flanges
32 of spaced channels 33 that are fixed on and are part of the
chassis. These channels form slots 35 between them for the bottom
ends 19a of the lazy tongs. Outer perimeters 34 of the outer races
are tapered thereby creating a horizontal thrust on both sides of
the ends of the bars 19a and keep the ends of the bars slidably and
centrally within the slots 35, when the lazy tongs frames are
extending or collapsing. These ends move in relation to the chassis
when the lazy tongs frames are extending co collapsing.
Secured to the underside of the platform on both sides there are
other channels 36 to movably retain other roller bearings 30a that
are mounted on ends 19b of the upper bars of the lazy tongs. These
roller bearings are mounted in the same manner as explained for the
roller bearings that are retained in the channels n the chassis.
This construction allows the upper ends 19b to move in relation to
the platform while the lazy tongs are raising and/or lowering the
platform.
The lazy tongs are actuated by a hydraulic system consisting of
primary booster rams and secondary hydraulic rams (see FIGS. 6 and
7). Secured to and fixed by saddle bolts on bottom frame members of
the chassis there are bearings 37 for booster hydraulic cylinders
39 on both sides of the chassis (see FIG. 10). Shaft 38 are
rotatably mounted in the bearings 37. Fixed on the shaft are the
hydraulic booster cylinders 39 that are rotatable with the shaft
38. The booster cylinders have piston rams 40 terminating in
hemispherical heads 41. The booster cylinders have hydraulic hose
lines 39a and 39b connected to a common hydraulic supply and return
line 39c that functions as a supply line and return line for
hydraulic fluid to the booster cylinders and secondary hydraulic
cylinders (to be explained). The booster cylinders have limited
rotation as indicated by dotted lines in FIG. 10 during the initial
upward movement of the lazy tongs bars. Secured to lower rods 19
there are concave blocks 42 (see FIG. 7) adapted to removably
engage over the hemispherical heads 41 during the collapsing of the
lazy tongs to move the booster cylinder and piston rams back into a
vertical position and thereby have the booster cylinders and piston
rams in position to assist in the next elevation of the platform.
The booster rams act on the lazy tongs in advance of action by the
secondary rams (to be explained) when the platform is being
raised.
Secured to the chassis there are stationary round rods 43 on each
side of the booster cylinders. At the outer ends of the rods there
are stop plates 44 that limit the outward rotation of the booster
cylinders. Slidably mounted on the rods 43 there are pusher plates
44a which are forced into engagement with the booster cylinder by
coil springs 44b. These bars and springs ensure the indexing of the
concave blocks over the hemispherical heads on the booster rams
when the lazy tongs are collapsing and are collapsed into the
lowest position in relation to the chassis.
There are two sets of secondary hydraulic cylinders 45 with rams
45a. Secured and fixed to the bars of the lazy tongs there are
other angle plates 46 in which are secured other bearing pins 47.
Bottoms 48 of the second hydraulic cylinders 45 are rotatably
secured on the pins 47. Extending between and fixed in the lazy
tongs bars there are other shafts 49 for rotatably securing head
castings 50 that are fixed on the secondary hydraulic cylinder rams
45a. These secondary hydraulic cylinder rams, together with the
booster rams, cause the lazy tongs to move the platform upward
easily and smoothly. The secondary hydraulic cylinders have
hydraulic hose lines 45b connected to the common supply and return
line 39c. The common supply and return line is connected to a
solenoid-actuated valve 45c. there are a multiple of
solenoid-actuated valves 72 secured to the chassis (see FIG. 12)
having a manifold 72a for selective distribution of the hydraulic
fluid flowing to and returning from a specific hydraulic
cylinder.
Fixed and supported on the chassis there is a reservoir 73 for
hydraulic fluid. Integral with the reservoir there is the hydraulic
pump and motor 70 (see FIG. 12). The manifold is connected to the
hydraulic pump by means of a hydraulic supply pipeline 74 and
hydraulic return line 75.
Secured on each side of the chassis there are other angle brackets
51 (see FIGS. 4 and 5) spaced apart to form a slot for rotatably
retaining arms 52 for right side and left side outriggers. The
outriggers arms are rotatably secured on hinge pins 53 that are
fixed in the angle brackets. Secured on outer ends of the arms
there are outrigger rubber-tired wheels 54 rotatably secured on
shafts 55 that are fixed in swiveled bifurcated bearing brackets 56
to allow the wheels to turn in the direction of travel. When the
wheels are down in contact with the floor the platform is thereby
secured from the swaying and/or tilting both in the down and
elevated position.
Fixed on a top side of the arms of the outriggers there are pillow
blocks 57 for the other hinge pins 58. Outrigger piston rods 59 for
the left outrigger and 59a for the right outrigger have bifurcated
ends 59b that are rotatably secured on the hinge pins 58 and the
piston rods 59 are adapted to slide back and forth in outrigger
hydraulic cylinders 60 and 60a that are fixed on the chassis. These
hydraulic cylinders with the piston rods are the means for moving
the outriggers up and down in relation to the chassis of the
platform.
The right side outrigger cylinder 60a is connected to a
solenoid-actuated valve 60g by means of hydraulic hoses 60b and 60c
(see FIG. 15). The left side outrigger cylinder is connected to a
solenoid-actuated valve 60d by means of hydraulic hoses 60e and
60f. Hydraulic pressure to the cylinders through the hoses 60b and
60c move the outriggers down and in contact with the floor.
Pressure to the other end of the cylinders 60 through the hoses 60c
and 60f raises the outriggers back up and away from the floor to up
in a vertical position.
A working surface 61 of a deck of the platform has a drop hinged
section 62 to increase the working area of the deck when the
section is down as illustrated in FIG. 1. The guardrails 17 are
hollow and slidably secured and extendable guardrails 63 adapted to
be slidably telescoped into the guardrails 17 when the drop hinge
section is up as can be seen by referring to FIG. 2 Bottom rails
17a which support the section in down position are slidably secured
in tubes secured to the bottom side of the platform.
Secured on the guardrail of the platform there is a pushbutton
control box 64 (to be explained). A steering lever 65 tiltable
right and left from upright is mounted in the top of the box. This
lever controls the steering of the vehicle carrying the elevator
platform when the platform is in elevated or lowered position.
Mounted on the side of the pushbutton control box there is another
tiltable drive motor control lever 66, that is adapted to be tilted
back and forth in relation to the pushbutton control box for
starting, accelerating, reversing and stopping the drive motor.
The rams for the hydraulic cylinders, that activate the outriggers
and the steering mechanism, are adapted to reciprocate alternately
in opposite directions. The solenoid-actuated valves are combined
with entrical holding valves 76 that have two ball checks. The
hydraulic lines are adapted to alternately become supply and/or
return lines for the hydraulic fluid. When the hydraulic fluid is
introduced into a line to make it a supply line under pressure the
ball checks will be unseated and convert, the other line to a
cylinder, into a return line. The conversion from supply to return
lines and vice versa is controlled by the solenoid-actuated
four-way valves. In every case when the lines are converted from
supply lines to return lines the fluid in the return lines will
return to the reservior 73 through the manifold and
solenoid-actuated valves. See FIGS. 15 and 16 to correlate the
electric circuits with the hydraulic systems.
There is a button for lowering the left outrigger and another
separate button for raising the left outrigger. To move the
outrigger down button 67 is depressed to close solenoid switch 67a
and pump switch 67b. The switch 67a connects the circuit through
the solenoid 67c into the main negative line 67d from a bank of
multiple-cell storage batteries 71 which are removably supported on
the chassis. The solenoid 67c when energized actuates the valve 60d
allowing hydraulic fluid under pressure to flow through hydraulic
hose line 60f. Simultaneously the hydraulic line 60e becomes a
return line. This causes the piston 59 to move to the left rotating
the left outrigger down onto the ground. The checks reseat
themselves and hold the outrigger down onto the ground.
Simultaneously with the depression of button 67 and closing of
switch 67a, to pump switch 68, for the left outrigger down motion,
is closed. This switch is connected in series with a pump relay
switch 79 which, when closed, completes the circuit to energize the
pump motor 70 and operate the pump. Hydraulic fluid is then forced
into the end of the hydraulic cylinder 60 for moving the outrigger
down to the ground.
The electric circuit and the hydraulic system for the movement of
the right outrigger down are identical to the left outrigger down
except that it has its separate button 80, solenoid switch 80a,
pump switch 80b, and solenoid 80c as illustrated in FIGS. 15 and
16.
For raising the left outrigger up there is a button 81 which, when
depressed, closes a solenoid switch 81a and a pump motor switch
81b. The solenoid switch 81a, when closed, energizes the solenoid
81c through the common main negative line 67d. The 67d is connected
to the bank of multiple-cell storage batteries 71. The pump motor
switch 81b, when closed, energizes the pump relay 79, closing
contact 79a to drive the hydraulic pump 70. This solenoid actuates
the solenoid valve 60d, reversing the flow of the hydraulic fluid
in hose line 60e which is now converted into a pressurized supply
line, and line 60f becomes a return line. Pressure on the piston
from the fluid through line 60e causes the piston 59 to move to the
right and thereby raise the left outrigger up from the floor. The
electric circuit and the hydraulic circuit for the movement of the
right outrigger up are identical to the left outrigger up movement
except that it has its separate button 82, solenoid switch 82a,
pump switch 82b and solenoid 82c as illustrated in FIGS. 15 and
16.
The steering lever 65 is tiltable to the right and left of a
vertical centerline through the axis supporting the lever. When the
lever is tilted to the right the vehicle and the platform will
gradually veer to the right and when the lever is tilted to the
left the vehicle and the platform will gradually veer to the left.
The steering lever actuates a reciprocable contact bar 83 (see FIG.
16) adapted to tilt to the right and close switches 83a 83b. when
the contact bar is tilted to the left it will close switches 84a
and 84b. The lever is spring actuated to return it when it is
released, to a position parallel to the vertical centerline. When
the lever is in the vertical position parallel to the vertical
centerline, all switches in the steering control circuit will be
open. When the lever 83 is tilted for steering to the right the
switch 83a is closed and a solenoid 86c is energized. When the
solenoid is energized it actuates the valve 15a. Simultaneously the
switch 83b is closed thereby energizing pump relay switch 79 and
relay contact 79a starting the pump motor 70. The pump forces the
hydraulic fluid under pressure into an end 12a of the steering
cylinder through the hose line 15 causing the rod 11 to move
towards another end 12b of the steering cylinder. While the rod is
moving in the direction of the end 12b, the steering wheels will be
turned to the right and thereby turn the vehicle and platform to
the right. Fluid in the end 12b of the steering cylinder will be
returned to the reservoir 73 through the line 15b which in this
case is a return line for the fluid. To steer the vehicle and
platform to the left, the lever 83 is tilted to the left. Tilting
the lever to the left closes switches 84a and 84b. The closing of
the switch 84a energizes a solenoid 84c which in turn actuates the
valve 15a. Simultaneously the switch 84b is closed and thereby
energizes the pump relay switch 79 through the line 67d the common
line connected to the negative side of the batteries. The contact
79a when closed energizes the motor 70 and drives the pump. The
pump forces the hydraulic fluid under pressure into an end 12b of
the steering cylinder through the hose line 15b thereby causing the
rod 11 to move towards the end 12a of the steering cylinder. While
the rod 11 is moving towards the end 12a of the cylinder, the
steering wheels will be turned to the left and thereby turn the
vehicle and platform to the left. The hydraulic fluid in the end
12a of the steering cylinder will return to the reservoir 73
through the hose line 15 which in this case in now a return
line.
The platform is adapted to be raised and lowered and held at any
level between the lowest and highest point of elevation of the
platform. When a workman on the platform desires to raise the
platform there is provided another pushbutton 88 in the pushbutton
control box. When this pushbutton is depressed it will close switch
88a for energizing a solenoid 88c through line 67d. When the
solenoid is energized it will actuate the valve 45c. Actuation of
the valve 45c causes hydraulic fluid under pressure to flow into
the hydraulic main line 39c. The fluid flows directly through
branch connections to all primary booster cylinders 39 and also
secondary cylinders 45. The pistons in the primary booster
cylinders react to the pressure in advance of the pistons in the
secondary cylinders. This advance reaction in the primary booster
cylinders starts the upward movement of the lazy tongs. After the
initial booster action the pistons for the secondary rams will
react to the fluid pressure and all rams will act in unison and
until the booster rams have reached their limits of upward motion.
At this point the secondary rams will continue to move the platform
upward to any desired height. Simultaneously with closing of switch
88a, pump motor relay 88b is also closed. Closing of pump motor
relay 88b completes the circuit through the pump hydraulic relay 79
which then energizes the motor operating the pump to circulate the
hydraulic fluid. A workman on the platform lowers the platform by
depressing a button 89, which closes a switch 89a completing the
circuit through and energizing a solenoid 89c. Energizing the
solenoid 89c activates the valve 45c which returns the hydraulic
fluid through the lines 39c and 45b from the cylinders 39 and 45
back to the reservoir. The weight of the platform on the secondary
rams and the primary booster rams forces the fluid out of the
cylinders and through the lines 39c and 45b.
Secured to the chassis there is a switchbox having pushbuttons 90
for elevating the platform and 98 for lowering the platform when a
workman is on ground level and off of the platform. The button 90
closes switches 90a and 90b simultaneously thereby energizing the
solenoid 88c. When the switches 90a and 90b are closed the cycle of
operation will be the same as described for elevating the platform
by the pushbutton 88 in the control box. When the button 98 is
depressed, by a person on ground level, a switch 90a is closed and
the solenoid 89c will be energized and operate valve 45c. When the
switch 90a is closed the cycle of operation will be the same as
described for lowering the platform by the use of the button 89 in
the control box on the platform.
At any given height when the particular buttons 88, 90, 89 and 98
are released, the solenoids are deenergized and hold their
respective valves in the neutral position. In this position all
valve parts are closed and the hydraulic fluid is held in static
condition and prevents the collapsing of the lazy tongs frames.
A key switch 91, across a main positive line 77, controls the on
and off for all electric circuits including the drive motor for the
vehicle. The positive line 77 connects to all circuits for the
controls of the hydraulic system. A manually lockout-type button 92
opens and closes a switch 93 across the positive line 77 and
negative line 67d.
The button is spring actuated and adapted to reciprocate to open
and close the switch 93 for momentary braking the movement of the
vehicle. To hold the vehicle in braked stationary position the
button is depressed and latched to hold the switch 93 in closed
condition. To release the vehicle from braked stationary position
the button is unlatched thereby allowing it to spring outward and
open the switch 93. Opening of the switch 93 deenergizes the
electromagnet and releases the brake allowing the vehicle to become
mobile. The closing of the switch 93 energizes a magnetic brake 94
that holds the vehicle with the platform from movement on level or
sloping ground. This ensures that the vehicle will remain
stationary when it is not propelled by the driving motor. All of
the hydraulic systems can function notwithstanding that the
magnetic brake is holding the vehicle and platform at rest. A
warning horn 95 is controlled by a switch 95a that energizes the
horn across the line 77 to line 67d. The horn is operated by a
button 96 in the control box on the platform. A main power fuse 100
and another control fuse 100 a are included in the electric circuit
for overload protection.
Secured on the chassis there is a limit switch 97 with a lever 97a
adapted to be detachably engaged by a lower arm of the lazy tongs
when the lazy tongs are completely collapsed down onto the chassis
of the vehicle. When the platform is raised a sufficient height to
be disengaged from the arm of the lazy tongs the limit switch is
opened. As long as the limit switch is open the speed of the drive
motor remains retarded through the silicon-controlled regulator 99
and the vehicle with the platform in raised position can only be
moved at a gradual pace. When the lazy tongs arm is in contact with
the limit switch lever the limit switch is closed. Closing of the
limit switch reacts through the silicon-controlled regulator 99
deenergizing the retarding electrodes and thereby allowing the
driving motor to attain maximum speed to move the vehicle and
platform at a greater pace.
The drive motor can only attain its maximum speed to move the
vehicle at a greater pace when the platform is in its lowest down
position.
* * * * *