Stair-climbing conveyance
First Claim
1. In a load carrying conveyance, the combination of:
- (a) a platform to receive the load;
(b) main drive and caster wheels supporting the platform for mobility;
(c) main endless belt tractor means supporting the platform for mobility;
(d) lever means carrying auxiliary endless belt tractor means disposed on pivots forwardly and rearwardly on the platform and outwardly off-set from the main tractor means and said platform to be operatively clear of said main tractor means and platform to permit rotation of said auxiliary tractor means without interference contact with said main tractor means or platform;
(e) power mechanism manually controllable by an operator for driving the drive wheels and the several tractor means, with said power mechanism operatable at a constant speed;
(f) rotational means for rotating said lever means concentrically positioned with said pivots and means for driving said rotational means; and
(g) mode conversion jack means manually controllable by the platform occupant for lowering the main endless belt tractor means until said main endless tractor belt means are in contact with the floor, and subsequently raising the main drive and caster wheels above the roots of the main endless tractor belt means, thus simultaneously converting the conveyance from a higher speed, level surface mode, to a lower speed, higher torque, stair climbing mode or vice versa, while remaining engaged to the main power mechanism operating at constant speed.
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Accused Products
Abstract
An improved power driven conveyance intended primarily for use by handicapped persons or invalids. A power means to drive the conveyance on level surfaces at normal pedestrian speeds and or to ascend or descend conventional or irregular stairways at reduced speed and increased torque. The invention further contains a self-leveling chair which automatically maintains the occupant in a level seated position regardless of the inclined position assumed by the conveyance frame, thereby contributing to the stability of the conveyance and the safety of the occupant. A fail safe tractor belt means is provided to insure a positive grip between the stair treads and the conveyance. Frontal and rear auxiliary tractor belt units adjust the inclination of the main tractor belts to alignment with the angularity of the stairways and landings.
106 Citations
24 Claims
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1. In a load carrying conveyance, the combination of:
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(a) a platform to receive the load; (b) main drive and caster wheels supporting the platform for mobility; (c) main endless belt tractor means supporting the platform for mobility; (d) lever means carrying auxiliary endless belt tractor means disposed on pivots forwardly and rearwardly on the platform and outwardly off-set from the main tractor means and said platform to be operatively clear of said main tractor means and platform to permit rotation of said auxiliary tractor means without interference contact with said main tractor means or platform; (e) power mechanism manually controllable by an operator for driving the drive wheels and the several tractor means, with said power mechanism operatable at a constant speed; (f) rotational means for rotating said lever means concentrically positioned with said pivots and means for driving said rotational means; and (g) mode conversion jack means manually controllable by the platform occupant for lowering the main endless belt tractor means until said main endless tractor belt means are in contact with the floor, and subsequently raising the main drive and caster wheels above the roots of the main endless tractor belt means, thus simultaneously converting the conveyance from a higher speed, level surface mode, to a lower speed, higher torque, stair climbing mode or vice versa, while remaining engaged to the main power mechanism operating at constant speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. In a conveyance for invalids the combination of:
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(a) a platform surmounted by a chair for the user; (b) main drive and caster wheels supporting the platform for mobility; (c) main endless tractor belt means supporting the platform for mobility; (d) lever means carrying auxiliary endless belt tractor means, disposed on pivots respectively forwardly and rearwardly on the platform and outwardly off-set from said main tractor means and said platform to be operatively clear of said main tractor means and platform to permit rotation of said auxiliary tractor means without interference contact with said main tractor means or platform, with each of said lever means swingable individually through a range of substantially 180°
;(e) reversible power driven mechanisms under manual control of the chair occupant for driving the wheels and several tractor means; (f) rotational means for rotating said several lever means concentrically positioned with said pivots and means for driving said rotational means; and (g) a pair of rollers attached to the forward lever means to prevent damage to carpets when transiting the upper landing or when positioning the conveyance to permit the occupant to reach a higher shelf than possible from a conventional wheel chair. - View Dependent Claims (12, 13, 14, 15, 16)
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17. In a conveyance for invalids the combination of:
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(a) a hollow platform surmounted by a seat for an occupant; (b) a pair of laterally spaced power driven side wheels and a pair of laterally spaced caster wheels longitudinally spaced from the side wheels by which the platform is supported ordinarily; (c) means operable manually by the occupant of the chair for driving the first mentioned wheels concurrently for forward or rearward propulsion of the conveyance, or individually to turn the conveyance either rightward or leftward or concurrently driving the wheels in opposite directions to obtain a minimum turning radius; (d) main endless tractor belts arranged respectively along opposite sides of the platform and trained about sprockets at the front and rear ends of the platform with their lower runs normally out of floor contact; (e) power operable jack means manually controllable from the chair for extending the main tractor belt assembly downwardly into contact with the floor, subsequently retracting the aforesaid wheels and platform upwardly until the said wheels are clear of the roots of the tractor belts thus permitting the cleated tractor belts to fully engage the leading edges of the stairs; (f) a pair of endless auxiliary tractor belts each trained about a pair of sprockets, one of which is coaxial with one of the frontal sprockets of the main tractor belts and the other of which is rotatably borne at the distal end of an arm fulcrumed on the axis of the corresponding frontal sprocket of the main tractor belts; (g) a second pair of endless auxiliary tractor belts each trained about sprockets one of which is coaxial with one of the rear sprockets of the corresponding main tractor belts and the other of which is rotatively borne at the distal end of an arm fulcrumed on the axis of the rear sprocket of the corresponding main tractor belt; (h) power means controllable from the chair for swinging the auxiliary frontal and rear tractor belt units downwardly from normal substantially upright idle positions into active angular positions in preparation for and during ascent or descent of stairways or the like by the conveyance; and (i) power means controllable by the occupant of the chair for driving the main and auxiliary tractor belts concurrently to effect stairway ascent or descent. - View Dependent Claims (18)
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19. In a conveyance for invalids, the combination of:
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a platform; a pair of drive wheels mounted on the platform; a pair of driven timing belts connected to the respective drive wheels; a pair of main endless tractor belts carried on forward and rearward sprocket wheels mounted on forward and rearward shafts, respectively; a pair of main propulsion drive motors hingedly mounted to the platform at one end and releasable by toggle clamps at the other end to permit disengagement of said motors from the driven timing belts to permit the occupant to hand propel the conveyance in the event of a power failure; interconnected drive trains from the drive motors to the drive wheels; a synchronizing jack means for raising one of the main tractor belts from floor contact, thence driving said main tractor belt until its cleats are synchronized with the other idle main tractor belt prior to ascension or descension of the stairs or the like; and a pair of parallel shaft double reduction worm gears driven by the drive trains; with the main tractor belts being driven by the drive trains and double reduction worm gears. - View Dependent Claims (20, 21, 22, 23, 24)
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Specification