Portable elevator working and load-lifting platform

Claim 2

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.

Claim 3

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.

Claim 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 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.

Claim 5

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 the 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.

Claim 6

A self-propelled lifting 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 tongs 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 trust element engageable with the said lower frame of the lazy tongs when 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 connected to the 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 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.

Claim 7

A self-propelled lifting 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 tongs 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 trust element engageable with the said lower frame of the lazy tongs when 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 connected to the 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 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.

Claim 8

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.

Claim 9

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.

Claim 10

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.

Claim 11

A self-propelled lifting vehicle comprising: a wheeled vehicle having a set of wheels including dirigible 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 at opposite sides for longitudinal motion relative 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 engageable 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 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 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.

Claim 12

A self-propelled lifting vehicle comprising: a wheeled vehicle having a set of wheels including dirigible 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 at opposite sides for longitudinal motion relative 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 engageable 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 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 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.

Claim 13

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.

Claim 14

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; 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.

Claim 15

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 steering cylinder in forward or reverse direction for guiding the path of motion of the vehicle.

Claim 16

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.

Claim 17

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.

Claim 18

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.

Claim 19

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.

Claim 20

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.

Claim 21

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.

Claim 22

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.

Claim 23

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.

Claim 24

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.

Claim 25

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 element 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.

Claim 26

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.

Claim 27

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.