Abstract: A rear wheel mounting assembly for a wheelchair having a frame with upper and lower longitudinal members vertically spaced from one another and disposed along the same side of the frame. The rear wheel mounting assembly includes an elongated upright member with a plurality of spaced apart recesses arranged longitudinally along an inward face. The elongated upright member includes a clamp disposed at each of its ends. One of the clamps is clamped to the upper longitudinal frame member and the other to the lower longitudinal frame member. The rear wheel mounting assembly includes a camber clamping assembly having an aperture for receiving and retaining an axle of a rear wheel and a removable clamp having a clamping surface engaged with a portion of the elongated upright member. The clamping surface comprises a projection received within one of the recesses of the elongated upright member.

Abstract: A wheelchair having a chassis formed from a flat plate folded to define a lower chassis, a chassis back, and an upper chassis. The lower and the upper chassis each have a pair of elongated substantially parallel arms that extend from respective land portions of the chassis. The arms define openings in distal portions for receiving caster wheels. Drive wheels connect to axle mounts that are selectively positioned for track, camber, and height, which axle mounts connect to the chassis back or to the lower chassis for stroller configuration. A seat support attaches to the upper chassis for supporting a person and includes independently adjustable height, longitudinal position relative to a seat back, and angle. A pair of push handles attach to the chassis back.

Abstract: A foldable wheelchair includes a frame having a seat bottom and a seat back movable relative to the seat bottom, wherein the seat back can be moved between a folded position such that the seat back extends generally parallel to a plane defined by the seat bottom and one or more unfolded positions to provide back support to a user. The foldable wheelchair can have a leg support movable relative to the seat bottom and can be moved between an unfolded position to support a user's legs and a folded position such that the leg support extends generally parallel to said plane defined by the seat bottom. In the folded position, the seat back, seat bottom and leg support define generally parallel planes.

Abstract: A wheelchair for carrying out abduction actions is proposed, which is fitted with a frame (1, 2, 3, 4, 5, 11) provided to support a seat (16) and side parts (14) arranged on both sides of the seat (16) and connected detachably to the frame, which parts can be adjusted for carrying out abduction actions in their angled position to the seat (16) in that they can be swivelled about a vertical axis (V) running substantially perpendicular to the seating plane.

Abstract: The wheelchair attachments are configured for removable attachment to a wheelchair to facilitate use of the wheelchair by occupants and/or attendants. One attachment is a retractable tray spanning the armrests at the front of the chair when deployed and retracting between the chair structure and a wheel for storage. Another attachment is a series of interchangeably installable handgrips or handles removably installable to the front or back of the chair for use by an attendant. At least some of the various handgrips or handle assemblies provide horizontal and/or vertical adjustment. Yet another attachment is an underseat storage compartment, primarily accessible by an attendant from the back of the chair. All of the various attachments may be installed upon and/or used with a wheelchair independently of one another or in combination with one another, or may be adapted for use with other devices as well.

Abstract: A hand-operated assembly that supplies secondary drive power and steering control to a secondary drive wheel of a wheel chair. The assembly comprises a handle that is controlled with one hand and a linkage rod that extends from the handle to an eccentric arm fitted to a one-way clutch assembly at a secondary drive wheel support axle. Reciprocating up-down, pivoting movements of the handle over a range Y? in the Y axis directs a linkage rod to rotate an eccentric arm fitted to a one-way clutch and a drive axle of a small diameter, secondary drive wheel. Independent 360° rotation of the handle about a second, horizontal or Z axis steers the secondary drive wheel. A portion Y? of the range of handle motion directs a flange at the linkage arm to engage a brake piece that contacts the secondary drive wheel. Large diameter, hand driven, primary drive wheels are separately available to the user for effecting normal chair conveyance.

Abstract: A pushrim with increased surface area and an insert between the wheel and the pushrim. In the preferred embodiment, the cross-section of the pushrim is an elongated circle and the insert is a concave trough made of an elastic material which compressibly fits between the wheel and the rim for convenient installation. Improved pushing is provided by texturing the surface of the insert to provide increased friction. Improved braking is provided by providing a smoother and wider surface on the pushrim.

Abstract: A modular wheelchair assembly is adapted to be reconfigured between a fixed angle of tilt, a dynamically adjustable tilt-in-space configuration with the tilt axis being near the user's knees and a dynamically adjustable tilt-in-space configuration with the tilt axis being near the user's center of gravity. The reconfiguration is achieved by modifying a limited number of selectively removable components of the support assembly or the pivot assembly of the wheelchair.

Abstract: The invention relates to a wheelchair provided with a support frame that is suspended on at least a rear wheel and a front wheel by means of a rear and front coupling. At least one coupling comprises means that can shift the support frame with respect to at least one wheel axle, such that a torque can be transmitted to the at least one wheel axle. In particular, the means comprise a lever, one end of which is rotatably connected to the relevant wheel axle and the other end of which is rotatably connected to the support frame. The invention also relates to a coupling mechanism, clearly intended for suspending a wheelchair support frame on a wheel of the wheelchair.

Abstract: A conveyance has a plurality of wheels and, at least, first and second drive axles, which are mounted, or disposed, between the wheels. One of the wheels defines a first wheel that is rotatably mounted to one end of the first drive axle. A second of the wheels is rotatably mounted to one end of the second drive axle. The conveyance further includes a first actuation device for the first drive axle, on the opposite end of the first drive axle from the first wheel and proximate to the second wheel, and a second actuation device for the second drive axle on the opposite end of the second drive axle from the second wheel and proximate the first wheel. The first actuation device is selectively operated to apply a selective relative rotation to the first wheel and the second actuation device is selectively operated to apply a selective relative rotation to the second wheel.

Abstract: A wheelchair which facilitates the storage of retractable leg rests within its side frames. These leg rest are independently able to be in the “stored” or “use” positions and continue to allow the wheelchair frame to be folded. The leg rest members are telescopically mounted to each other and allow for leg length adjustment on this telescopic slide. This leg rest assembly has angle adjustability to suit multiple angles of the occupant's knees for comfort.

Abstract: The present invention is a combination walker and wheelchair which enables a person with back problems and other physical disabilities to walk from one location to another without assistance from a third person with correct walking posture and arm movement, thereby allowing long walks versus crutches of current design and also enables the person to comfortably sit in the chair in spite of the person's back pains. The ergonomically friendly design includes a high level transverse bar which enables the invention to be pushed by a person's hands, arms and chest or enables the person to lean against the invention; a foldable main structural frame; a detachable back support and seat; and rotatable wide armrests made with compressive materials thereby allowing the chair structure the maximum width to get through standard doors and still have even wider comfortable armrests. Therefore, the present invention can be used as a walker, a wheelchair, a transportation chair, a golf trolley, and a spectator chair.

Abstract: An all terrain adapter for a wheelchair that removably clamps onto the foot support of the wheelchair and supports a relatively large diameter, slightly inclined swivelling nose gear wheel at an extended distance from the foot support to stabilize the wheelchair when it is being pushed over soft or uneven surfaces and which swivels around when the wheelchair is moved forward to lift the front wheels of the wheelchair clear of the ground.

Abstract: A person carrying vehicle includes a main frame, a seat pivoted on the main frame, a front frame, an articulate supporting member connecting the main frame and the front frame, and a telescopic steering mechanism pivoted on the front frame; by means of pivoting supporting rods of the seat downwards, folding the articulate supporting member as well as shorting and pivoting the steering mechanism, the vehicle can be reduced into a not-in-use configuration, wherein the supporting rods and a seat pad are received in a hollow holding portion of the main frame, a footrest board of the front frame hidden under the main frame, and a tube part of the steering mechanism is received in grooves on the seat; the vehicle has a lift handle at a front, and auxiliary casters at a rear, which are used for the vehicle to be moved in a sloping position on the floor.

Abstract: Stem (12) is secured to fork (6). Head (27), bearing surface (28), recessed portions (29 and 21), and bearing surface (31) successively engage the interior of housing (13), comprising first bearing (14), laterally movable locking ring (18) and second bearing (15). Locking ring (18) is repelled to the left in diametral direction against spring means urging ring (18). When shoulder (20) has arrived at the height of rim portion (32) of ring (18) the spring means are released. Ring (18) displaces to the right and portion (32) engages groove (29) thus locking the stem in the axial direction. Due to the side location of the button 9, the device can easily be handled using the palm of a hand.

Abstract: A wheelchair having a rotatable vertically adjustable seat that can rotate at least 180 degrees. A vertical adjustment means adjusts the seat from a base position to an elevation above the diameter of the wheel chair drive wheels. The seat can swivel or be fixed by an anti-rotation means. The wheelchair can be conventionally configured with guide wheels forward or reversed with drive wheels forward for use on rough ground or uneven surfaces.

Abstract: A wheelchair wheel positioning system for providing an unobstructed path into and out of a wheelchair. The wheelchair wheel positioning system includes a frame member fastened to a wheelchair frame, an actuation member pivotably connected to both a frame bar and a rear wheel of the wheelchair and a stabilizer member utilized for lifting and maintaining the wheelchair in place. The actuation member pivotally connects at one end to the frame member and pivotally connects near the middle to a rear wheel of the wheelchair. The stabilizer member is affixed near the middle of the actuation member at a preferred angle. As the actuation member and rear wheel are rotated rearward, the stabilizer member contacts the floor surface to lift the rear wheel that the wheelchair wheel positioning system is attached to and stabilizes the wheelchair for entry and exit.

Abstract: A toileting chair has a flexible seat support and a removable seat. The removable seat is positioned on a seat support platform. At least one of the seat support platform and the flexible seat support is vertically movable with respect to the others so as to permit the insertion and removal of the seat. The flexible seat support is independent of the drive means so as to provide a comfortable suspended support on which a person may be seated during the reconfiguration of the chair.

Abstract: A handling device for persons with a limited gripping function, in particular for gripping utensils such as pens, comprising an orthotic support adapted to be secured to a part of the body of the person; a utensil holder situated on the support, wherein the utensil holder includes gripping means; and a pneumatic, electric, or magnetic drive system or a combination thereof operative on the gripping means. Also described is a wheelchair, comprising the aforementioned handling device, thus allowing optimum carrying and operation or use of the device.

Abstract: The present invention is directed to a bi-folding wheelchair (10) with side frames (12) and (14) that fold together with a compound scissor action moving the large rear wheels (96) to a central location while the backrest (50) is folding downwardly. Two separate locking mechanisms (28) and (40) hold the frame apart in the upright position while two additional locking mechanisms (77) hold the backrest (50) upright or down in the collapsed position. All the major components of the conventional wheelchairs like the foot rests, the arm rests, large wheels, caster wheels and the backrest fit into a compact package narrower than the unfolded wheelchair and slightly larger than the diameter of the back wheels with all parts folding in and out simultaneously. The large rear wheel assemblies can be quickly removed further reducing the size and weight of the device for shipping or storage.

Abstract: The present invention relates to an apparatus for automatic brake of walking support machine which is safe on downward slopes by preventing over speed due to the acceleration of gravity and protect user on upward slopes.

Abstract: A wheelchair includes a standard foldable frame for supporting a seat with a first and second drive wheel driven by drive levers. Each wheel has a transmission providing for three forward speeds and a reverse speed, as well as a neutral position. The transmissions for the two wheels may be constructed of identical parts with the wheels being caused to rotate in opposite directions from the driving lever merely by reversing the direction of the pawls within the transmissions. The ratchet drive surfaces are provided with pawl engaging surfaces which may be driven in either of two directions. The wheelchair does not require any bulky equipment and the hub containing the transmission may be the size of a bicycle hub. The transmissions in both wheels are shifted by a single control. The wheelchair is provided with disk brakes.

Abstract: A wheelchair includes a seat carried by a frame including at least one front wheel and opposed rear wheels. A circular handrim is coupled to one of the rear wheels with spaced-apart connecting pins. A framework is secured to the handrim, and a ratchet operatively couples an inner end of a lever to the framework. The lever extends upwardly from the ratchet to the outer end allowing a user seated in the seat of the wheelchair to grasp the outer end of the lever and move the lever between a first position and a second position. The ratchet acts on the framework to impart rotation to the one of the rear wheels in response to movement of the lever between the first and second positions.

Abstract: An inter-convertible single person type transporting aid (10) comprises a multi directionally propellable wheeled carrier frame (12) that is fitted with drive wheels (14) that are independently drivable via motors (16) and situated to enable aid central axis turning. The frame (12) is constituted from an upper frame part (20) displaceably mounted to a wheeled base frame (22) fitted at its outer corners with castors (24). The upper frame part (20) is biased in the direction of arrow (30) relative to the base frame (22). The aid (10) is re-arrangeable into a walk supporter or walker (38), a sitting transporter and a standing transporter by the removable fitting of a seat and a standing platform respectively.

Abstract: The present invention discloses an omnidirectional movement control system, having a move signal generator for generating a plurality of movement signals based on a plurality of first position signals and a plurality of second position signals, and an omnidirectional movement controller for generating a plurality of pulse width modulation signals and a plurality of motor direction change signals based on the movement signals and a plurality of motor encoding disc signals, and a driving circuit for driving motors to rotate a plurality of omnidirectional wheels based on the pulse width modulation signals and the motor direction change signals, such that a mobile platform can be moved in any direction and rotated in different directions, so as to provide excellent mobility and flexibility to the mobile platform.

Abstract: The invention relates to a wheelchair, including an assembly of a chair unit for a user and a support base supporting the chair unit, wherein the support base includes a number of carrying wheels for carrying the assembly, a drive element connected to the assembly for driving at least one carrying wheel and, an operating element connected to the assembly for operating the drive element. The invention also relates to an operating element for use in such a wheelchair.

Abstract: Wheelchair seat back mounting hardware permits the seat back to be mounted on various wheelchairs. The mounting hardware may be in the form of two-point mounting hardware that connects the seat back to the wheelchair and permits the seat back height to be adjusted independently of the mounting hardware location on the wheelchair.

Abstract: A stand-up wheelchair with a chassis, at which two drive wheels and at least a one guidable wheel is fastened, on which a stand-up unit with a seating surface, a backrest and at least one tiltable footrest is arranged, whereby reciprocally underneath the seating surface an upper longitudinal rail and a lower longitudinal rail are arranged, the upper longitudinal rail is firmly connected with the seating surface and both longitudinal rails are connected over four hinge points with their rear ends connected with a backrest, characterized by the fact that the rear ends of the longitudinal rails show a slot, in which the backrest can be longitudinally adjusted with their lower ends.

Abstract: The present invention provides a suspension for a conveyance that is capable of traversing obstacles and rough terrain. The suspension includes a frame, a pivot arm, a front caster, a drive assembly and a rear caster. The pivot arm and the drive assembly are coupled and decoupled based on movement of the drive assembly.

Abstract: The present invention provides a kit for attaching a manually operated wheelchair to a motorized scooter having a seating apparatus and supporting structure and a floor, comprising: (a) a motorized scooter attachment angle iron, wherein the angle iron comprises: (i) a vertical wall; and (ii) a horizontal wall, the horizontal wall forming approximately a right angle to the vertical wall, wherein the horizontal wall has at least two embedded elongated slots; (b) an angle iron attachment adjustable bar, wherein the adjustable bar comprises (i) a left elbow shaped tubular segment having a horizontally oriented bottom end and a vertically oriented top end; (ii) a right elbow shaped tubular segment having a horizontally oriented bottom end and a vertically oriented top end; and (iii) a straight middle tubular segment having a diameter larger than the left segment and the right segment, so as to permit the left segment to insert into a left end of the middle tubular segment and so as to permit the right segment to i

Abstract: The present invention relates to the art of personal mobility vehicles, particularly vehicles for the physically impaired. Particular application is found in children's wheelchairs which grow and expand with the child. However, it is to be appreciated that the present invention may also be applicable to wheelchairs for adults and may be utilized to custom fit wheelchairs to adults, may enable the chair to be utilized by adults or children of different sizes, or may be applicable to other vehicles.

Abstract: A self-propelled wheelchair with independently driven wheels and dual support frames connected in an articulating relationship. A front frame supports a seat and a rearward extended pivot connector. A pair of front wheels and left and right front drive units are connected to the front frame. A rear frame includes a forwardly extended pivot joint, a rear support platform having a power source thereon, and a pair of rear wheels and left and right rear drive units connected thereto. An articulating junction is formed by the front frame pivot connector attached to the rear frame pivot joint and providing articulation between the front frame and rear frame. A manually operable control unit includes computer circuitry in connection with each wheel drive unit, wherein manipulation of the control unit actuates each drive unit for control of rotational speed and direction of rotation for each wheel.

Abstract: A mobility device for use by the elderly or disabled persons, that does not require standing, balancing or walking and is propelled by leg paddling of a user, is disclosed. The mobility device comprises a pair of base members, an inverted U-shaped member disposed between the base members, front legs extending downwardly at 45 degrees with respect to the base members with swiveling wheels, a front cross bar disposed between the front legs, such that the front cross bar and the front legs define an opening receiving a user's legs while paddling. Also provided are rear legs with fixed wheels, handles extending outwardly at 70 degrees with respect to the base members, brakes engaging rear wheels, the brakes actuated by levers disposed on the handles, a seat, a back rest and arm rests.

Abstract: A driving system allows an invalid chair having a seating structure, wheels on both sides of the seating structure and at least one front stabilizing wheel, to pass obstacles. The driving system has arms secured to both sides of the seating structure and on which shafts of the wheels are arranged slidingly within two extreme positions. Cranks are on both sides of the seating structure and rotary cross engagement members are at the rear and on both sides of the seating structure and have arms which are terminated with adhesive end pieces. Each crank is connected to a respective rotary cross engagement member through a geared transmission for transmission of rotary movement of the crank to the rotary cross engagement member, and the geared transmission is provided with a flap for preventing reverse rotating of the crank.

Abstract: The present invention provides an improved wheelchair—comprising a chassis, which has a lower chassis section pivotally connected to an upper chassis section, such that the upper chassis section can pivot in relation to the lower chassis section about a substantially horizontal axis;—where said lower section comprises two substantially parallel load carrying members, oriented in a direction parallel to the intended travelling direction of the wheelchair;—where the load carrying members are spaced in a direction perpendicular to the travelling direction by at least one transverse member;—where means are provided for detachably mounting rear wheels where the transverse member intersects each of the load carrying members;—and where close to, or as a part of, the mechanism pivotally connecting the upper and lower section, means are provided for attaching front wheels, said wheel mounting being pivotable about a vertical axle;—where means are provided for slidingly attaching a seat to the upper chassis section, sa

Abstract: A collapsible wheelchair frame having left and right side plates, each having an upper end, a lower end, and a forward end, each forward end forming a forwardly and downwardly and extending leg; left and right seat plates, each seat plate having proximal and distal ends, the proximal ends of the left and right seat plates being respectively hingedly attached to the upper ends of the left and right seat plates, the distal end of the left seat plate being hingedly attached to the distal end of the right seat plate; and left and right brace plates, each brace plate having proximal and distal ends, the proximal ends of the left and right brace plates being respectively hingedly attached to the lower ends of the left and right side plates, the distal end of the left brace plate being hingedly attached to the distal end of the right brace plate.

Abstract: Height-adjusting wheelchairs allow an occupant of the wheelchair to adjust the height of the wheelchair seat above the ground. A height-adjusting manually propelled wheelchair may include a base frame supported by two rear wheels, and a vertically movable seat assembly is positioned above the base frame. A height adjustment system adjusts the height of the seat assembly relative to the base frame.

Abstract: An adjustable matrix wheelchair seat can be mounted on a pair of rods such as are provided on the seat rails of a typical wheelchair or on any pair of rods adapted to be rigidly fixed to and aligned in a longitudinal direction relative to the frame of the wheelchair. A lateral array of spaced apart substantially inelastic straps is extended between and engaged on the rods. A longitudinal array of spaced apart substantially inelastic straps is engaged on the forwardmost and rearwardmost straps of the lateral array. The longitudinal array traverses the lateral array to define a horizontal matrix of ventilating interstices. The length of any or all of the straps of the lateral and horizontal arrays is independently adjustable to permit alteration of the pressure pattern imposed on the arrays by the patient occupying the seat.

Abstract: Apparatus for connecting together two objects comprises: a body for attachment to a first object and having a concave surface and a corresponding convex surface; a clamp for attachment to a second object and having a first jaw and a second jaw moveable relative to the first jaw, the first and second jaws being configured to engage respectively the concave and convex surfaces of the body when applying a clamping force thereto, wherein at least one jaw comprises at least one tooth configured to bite into the body as the clamping force is applied, thereby resisting movement between the body and the clamp. A chair, in particular a wheelchair for disabled persons, has one or more rests mounted on apparatus as detailed above.

Abstract: A wheelchair is capable of radiographing with the wheelchair as is by using a general radiographic device, without a need to switch to a different chair. The wheelchair includes a seat portion, a backrest portion provided with upper frame bodies mounted approximately perpendicular to the seat portion and a main body detachably mounted to the upper frame bodies transversely of the upper frame bodies, holding portions installed consecutively to the upper frame bodies, and wheels. The upper frame bodies are approximately perpendicular to the ground plane of the wheels, the main body is configured of an X-ray transmissive material, and the holding portions are installed consecutively to the upper frame bodies detachably and turnably.

Abstract: An indoor wheelchair comprising a carriage with a seat having left, right, front and back edges, a backrest, four carrying wheels and supporting members connecting the seat to the carrying wheels; a left and a right riving mechanism mounted to the carriage, each driving mechanism including a manual driving wheel and a transmission connecting the manual driving wheel to one of the respective left and right carrying wheels, The wheelchair is characterized in that it is free of elements occupying the space under the seat between the innermost surfaces of the driving mechanisms and between the rear carrying wheels so that the wheelchair can be rolled over a common toilet bowl in backward motion, while the overall width of the wheelchair as defined between the outermost surfaces of the driving mechanisms allows passing to the wheel chair through a common bathroom door.

Abstract: A wheelchair having a two-stage tilt ability is provided. The wheelchair includes a base frame and a seat mounted to the base frame. The seat is configured for rearward tilting. A mounting mechanism is connected to the seat. The mounting mechanism is configured to tilt the seat by a first pivoting of the seat through a first range of tilting about a first pivot axis and a second pivoting of the seat through a second range of tilting about a second pivot axis.

Abstract: A manual transport wheelchair for transporting a person is changeable between a transport position and a folded position. The wheelchair has two side frames coupled by a single scissor frame that is movable to change the wheelchair between the transport position and the folded position. The wheelchair has a weight capacity-to-weight ratio of at least nineteen.

Abstract: A collision damage prevention system is disclosed which may be installed on many standard powered mobility vehicles for handicapped persons. The system includes an array of one or more sensors placed around the periphery of the powered mobility vehicle, a switch for each sensor, and a central control module which receives input from the switches, turns the vehicle off and/or applies braking power to prevent damage from a collision. The system then prompts the operator to acknowledge the collision and guides the operator into the appropriate direction to move the vehicle's controls in order to move away from the object collided with.

Abstract: A foldable wheelchair comprises a substantially horizontally extending upper side frame member. An upper end of an axle plate is secured to the upper side frame member. An axle housing is secured to the axle plate. A cross brace is pivotally secured directly to the axle plate at the lower end of the axle plate. A wheel mount assembly comprises an axle sleeve mount having an internal thread. An axle sleeve has an external thread that is in threaded engagement with the internal thread of the axle sleeve mount. The axle sleeve has an internal bore that accepts a wheel axle. The internal bore is angled with respect to the axis of the external threads to provide camber to a wheel. The axle sleeve is adapted to provide lateral adjustment to the wheel by rotating the axle sleeve within the axle sleeve mount any number of complete revolutions.

Abstract: An input device, such as a joystick, provides proportional input signals related to a position of an actuating member along an actuation surface and also includes a switch that provides an additional signal when the actuating member is moved in a direction perpendicular to the actuation surface.

Abstract: An improved wheel assembly comprises a caster fork, a caster wheel rotatably supported by the caster fork, and a caster swivel post defining an axis about which the caster fork rotates. The caster swivel post is being adapted to rotate about a pivot axis within a cylindrical housing. Alternatively, the wheel assembly has an adjustable axle for varying the camber angle of a wheel. The wheel assembly comprises a housing and an axle supported by the housing. The axle in turn rotatably supports a wheel. The axle is adapted to rotate about a pivot axis within a cylindrical housing.

Abstract: The wheelchair comprises a seat and two main wheels connected by an axle. A support device, comprising an exchangeable intermediate element consisting of an elastomer element located in the lacuna provided by the spiral turns of a spring, is detachably fixed at one of its end to a chassis of the seat and at its other end to the axle through a center part attached to the middle part of the axle. The center part is arranged to receive the rear ends of the two left and right main frame tubes of the wheelchair.

Abstract: The improved wheelchair employs the use of two push levers attached to two forward drive gears, and two reverse drive gears, which propel the two main rear wheels of the chair through bicycle chains connecting the front drive gears to sprocket clusters mounted on the rear wheel axles. Direction control mechanisms allow the user to engage either forward or reverse drive gears, or disengage both, thereby producing forward, neutral, and reverse motion. Derailers are mounted behind each rear axle and are activated by shifter mechanisms mounted on the push levers. Disc brakes are mounted on the frame beside each wheel and activated by hand brake levers mounted on the push levers.

Abstract: A power wheelchair is provided having one or more anti-tip wheels for stabilizing the movement of the frame about the drive wheels. An anti-tip wheel is attached to the end of a suspension arm which is pivotally attached to the frame of the wheelchair. A spring resiliently supports the anti-tip wheel in a neutral position relative to the ground upon which the drive wheels of the wheelchair normal ride. A retaining system selectively fixes position of the anti-tip wheels relative to the frame. The retaining system employs a plurality of teeth, with one portion disposed in combination with said suspension arm, and at least one other tooth disposed for engaging said one portion to provide unidirectional retention of the position of said suspension arm relative to the frame. The engagement of the teeth to lock the position of the suspension arm may be responsive to the torque generated by the motor.