Abstract: A waste disposal system, the waste disposal system including: (a) a sitting surface, for supporting a body of a user; and (b) a flexible basin including a drainage hole at a lower part of the flexible basin, wherein a rim of the flexible basin is connected to the sitting surface; wherein a shape of the flexible basin may take a first shape and a second shape, the first shape being a non-operational shape, and the second shape being a basin for guiding urine of the user to the drainage hole; wherein a distance between the sitting surface and the drainage hole is different between the first shape and a second shape.

Abstract: Several new and useful concepts for a manually propelled vehicle such as a wheel chair are provided. In one concept, the vehicle is configured to be selectively placed in an automatic lock condition in which (i) the wheel chair can move in a conventional manner while an occupant is seated in the wheel chair, and (ii) the wheel chair is automatically locked against movement when an occupant begins to rise from a seated position on the wheel chair. In another concept, a particularly secure structure is provided for locking the wheel of the wheel chair against movement. In yet another concept, important components of the wheel chair are formed in a manner that facilitates assembly of those components into the wheel chair, by an internal fastening system and in a modular fashion.

Abstract: A drive system (3) for a human powered vehicle. The drive system (3) includes at least one input member (31), a transmission system (21) arranged to convert movement of the input member (31) to rotation of an output member (83), and a lock mechanism (123) including at least one drive member (133) for selectively locking a drive wheel (11, 13) to rotation of the output member (83) for rotation therewith. The drive member (133) is arranged for movement from a first operational position in which the drive wheel (11, 13) is not locked to the output member (83) to a second operational position in which the drive wheel (11, 13) is locked to the output member (83), and back to the first operational position, under the control of a user of the vehicle. The drive system (3) allows the user to choose between propelling the vehicle using the drive system (3) or disengaging the drive system (3) from the drive wheel (11, 13) and propelling the vehicle by some other means, for example by wheel rims.

Abstract: A wheelchair frame assembly comprises a frame member having a first leg adapted to support a seat and a second leg configured to support a caster wheel. An axle mounting assembly connects an axle tube to the frame member. The axle mounting assembly includes an axle tube mount, a frame mount, and a spacer. The spacer is configured to alter the distance between the frame member and the axle tube and transfer longitudinal forces between the axle tube mount and the frame mount.

Abstract: A wheelchair comprises a base frame, a backrest frame and a hinge assembly. The base frame has first and second side frame members. The hinge assembly connects the backrest frame to a portion of the base frame for selective pivotal movement. The hinge assembly includes a locking mechanism configured to provide selective discrete locking positions of the backrest relative to the base frame. The locking mechanism includes a locking pin and a plurality of cooperating locking apertures. The locking pin is adapted to selectively engage one of the plurality of locking apertures to define a backrest angle relative to the base frame. One or more plugs are adapted to engage one or more of the plurality of locking apertures to prevent the locking pin from cooperating with the plugged locking aperture.

Abstract: Seat cushions that prevent a seated handicapped individual from sliding forward on the seat, while preventing the occurrence of decubitus ulcers. The seat a seat cushion includes a resilient body having a generally rectangular shape. The resilient body includes a frontal portion having a front end and a rear end, and which is fabricated from materials having a first density, and a rear portion having a front end and a rear end, and is fabricated from materials having a second density. The first density is substantially higher than the second density. Preferably, the resilient body is fabricated out of a sturdy foam material. Preferably, the seat cushion further includes a protective cover wrapping the resilient body.

Abstract: An improved wheelchair and a method of security screening a wheelchair are disclosed. The wheelchair is constructed of plastic and includes an antimicrobial agent. The wheelchair also includes a plurality of safety features. In a method, the wheelchair is tested for compliance with safety and security standards. If compliant, the wheelchair is certified by locating certification information on the wheelchair and the wheelchair is provided for use. Before each use, the wheelchair is validated by confirming the existence of the certification information. The wheelchair is then used to transport a user to and through a security checkpoint while the user remains seated in the wheelchair, including as the wheelchair passes through checkpoint screening.

Abstract: A wheelchair with enhanced toilet access which facilitates independent use of the wheelchair by the user without intervention by caregivers. The wheelchair with enhanced toilet access includes a frame which includes a pair of laterally-separated side frame portions, with primary wheels as well as at least one secondary wheel rotatably mounted on the frame. A seat extends between the side frame portions, and includes a stationary portion and a movable portion.

Abstract: A wheelchair transfer device comprises a base frame, an elevation unit and a transfer unit, whereby a caregiver can easily and fast move the disabled person from the wheelchair to the bed or from the bed to the wheelchair. The elevation unit has a moving component that can ascend or descend. On the top of the moving component is a seat pad having an upper seat body and a lower seat body. A transfer unit with a positioning unit is arranged at the bottom of the upper seat body. Track levers are arranged on two sides of the positioning unit. The track levers can extend and retract and allows the upper seat body to slide thereon. Thereby, the caregiver can easily and fast move the disabled person to or from the wheelchair without lifting the disabled person manually and laboriously.

Abstract: A wheelchair having a lower frame with drive wheels and forwardly extending arms with casters and an upper frame with a seat and backrest. Linkage assemblies on opposing sides pivotably attach at a first end to the lower frame and at a second end to the upper frame. Power cylinders attached on opposing sides are extendable between the upper frame and the lower frame and are lockable from moving from a selected position. When unlocked, the power cylinders apply a supplemental force in association with a force applied by a user on the drive wheels for moving the upper frame relative to the lower frame guided by the linkage assembly. A method of adjusting the seat height of a wheelchair is disclosed.

Abstract: A mobile chair assembly includes a pair of wheels rotatably supported by a frame, a seat assembly mounted to the frame; and a transfer board assembly movable between a first position and a second position. The transfer board assembly includes a rigid transfer board and an attachment assembly. In the first position, the rigid transfer board and the attachment assembly are disposed under the seat assembly and in the second position, the rigid transfer board extends laterally from the seat assembly. The seat assembly includes a seat support pivotable relative to the frame; and a back support pivotably attached to a back of the seat support. In a folded position, the seat support and back support form an acute angle to one another and the seat support is inclined relative to the frame.

Abstract: A wheelchair suspension system includes a suspension member which clamps to longitudinal bars of the wheelchair frame located below the seat of the wheelchair. The suspension member is elongate with upper and lower parallel leaf springs extending between the opposing ends of the suspension member. An axle support member is hinged to each end of the suspension member, by pivotal connection to each of the leaf springs. Each axle support member receives the axle of one of the opposing large rear wheels of the wheelchair. As the large wheels encounter uneven areas on the ground surface on which the wheelchair moves, the leaf springs flex reducing vibrations and shock to the wheelchair occupant. The axle support members maintain their generally upright orientation as the leaf springs flex so that camber angle of the rear wheels does not change.

Abstract: A propulsion apparatus (20) which can be mounted to a wheel (8) (or integrally formed therewith) of a vehicle, for example a wheelchair. The propulsion apparatus (20) has a first portion which can be statically attached to either a rim of the wheel (8) or structural member which is rigidly attached to the wheel (8) projects therefrom. The propulsion apparatus (20) also has a second portion (23), which is pivotal about the rotational axis of the wheel (8). Furthermore, the propulsion apparatus (20) comprises coupling means which are interposed between the first and second portions so that when the second portion (23) is rotated about the axis of the wheel (8) it causes the first portion, and therefore also the wheel (8), to rotate.

Abstract: The present invention relates to a mobile vehicle or wheelchair having the ability to provide stabilized transport to at least one individual on a variety of surfaces, slopes and/or terrains. In one aspect, the invention provides adjustment features allowing the mobile vehicle or wheelchair to accommodate individuals of various sizes and shapes. For example, the invention comprises a seat and an adjustable footrest which can be lengthened or shortened to accommodate different size individuals, including children. In one embodiment the distance between the footrest and the seat can be increased or decreased to accommodate different leg lengths of different individuals. The mobile unit or wheelchair of the invention may travel across smooth and very rough surfaces, slopes of varying or different angles and various outdoor terrains (including grassy, rocky, sandy, muddy and/or hilly terrains).

Abstract: Each wheel (10, 14/20, 24) of the wheelchair (1) is fixed to a suspension arm (11,15/21, 25). A force transmitting device, for example a spring and damper of the wheelchair unit, directly connects two suspension arms situated on the same side of the wheeled conveyance, so that forces exerted on one of the wheels are transmitted to the other wheel. In this way, obstacles can more conveniently be overcome. A further advantage of the wheelchair is that it can be easily upscaled and driving properties can be adjusted according to a user's preferences.

Abstract: Gentle and substantially linear vertical motion of a wheelchair foot support is expected to provide superior results for maintenance of a wheelchair user's leg muscle mass' thus reducing atrophy of the wheelchair user's legs. Additionally, gentle continuous motion of the foot support is expected to aid in maintaining elasticity of the wheelchair user's leg joint ligaments' thus reducing contractures. Accordingly, an atrophy-reducing wheelchair includes a movable foot support mounted to a linkage that is movably connected to the wheelchair frame. As the wheelchair moves in normal operation, rotation of a wheelchair wheel drives the linkage to provide substantially linear vertical reciprocation of the foot support.

Abstract: A wheelchair comprises a pair of spaced apart side frame tubes and a pair of foot support frames. Each of the foot support frames has a first end configured to connect to the side frame tubes and a second end configured to receive a cross member. The cross member interconnects the second ends of the foot support frames and supports a foot support 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: 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: A walker for use by those with limited mobility. The walker includes a seat assembly that assists the user in rising from a seated position or sitting from a standing position. The seat assembly is mounted in a frame and includes at least one gas spring mounted between the seat assembly and the frame that deflects the seat assembly while the user is rising from the seat or dampens the deflection of the seat when the user is sitting. The walker may include other capabilities and attachments, including a braking system and mountings for ancillary equipment.

Abstract: A propulsion unit for a wheelchair wheel with a track. The propulsion unit comprising a body having a front portion, a rear portion and a handle, at least three rollers pivotally mounted to the body, front and rear friction elements positioned in the front and rear portions of the body respectively. When the handle is pressed forward the wheel is propelled forward and when the handle is pressed rearward the wheel is propelled rearward.

Abstract: A wheelchair comprising a modular and adjustable configuration. The wheelchair comprises a mainframe, a seat assembly, and a caster wing assembly. According to an embodiment, the seat assembly includes adjustable side guards and/or a backrest. According to an embodiment, the wheelchair includes a suspension system coupled between the mainframe and the seat assembly. According to an embodiment, the caster wing assembly includes an adjustment mechanism for adjusting the horizontal and/or vertical position of the footrest with respect to the mainframe. According to another embodiment, the caster wing assembly includes a leg or calf rest member having a comfort shaped profile. According to another embodiment, the seat assembly comprises a structurally independent component. According to another embodiment, the caster wing assembly comprises a structurally independent component. According to another embodiment, the mainframe comprises a structurally independent component.

Abstract: A wheeled chair for assisting a user in changing a disposition. The chair comprises: a base member, a substantially planar seat member, a leg bracing member, a back bracing member, a bracing motor, and an actuator module. The base member includes a plurality of wheels and a lift device. The seat member is oriented substantially orthogonal to the direction of motion of the lift device. The leg bracing member includes a first mode wherein it extends downwardly from the seat member and a second mode wherein it extends substantially collinearly from the seat member. The back bracing member includes a first mode wherein it extends upwardly from the seat member and a second mode wherein it extends substantially collinearly from the seat member. The bracing motor changes between the two modes. The lift device includes a lift device motor. The actuator module activates the bracing and lift device motors simultaneously.

Abstract: A drive assistance device for a wheel chair having a drive motor, a driving wheel, a sensor means which is designed such that a driving force manually induced into a driving wheel is detected, and a control unit, designed such that the drive motor is controlled to drive the driving wheel in accordance with a drive assistance degree depending on the driving force manually induced into the driving wheel, wherein the control unit comprises an anti-rollback operational mode in which it is adapted to control the drive motor such that an unintended rolling of the driving wheel is avoided. The invention also relates to a wheel chair having such a drive assistance device.

Abstract: A wheelchair having torsion-acting shock absorbers from which cantilevered swing arms connected to drive wheels are connected is disclosed. The wheelchair incorporates a compact, collapsible power scooter that attaches to the wheelchair and presents a pair of handlebars having an accelerator and a brake, thus enabling the rider to propel him or herself by a power drive train rather than by hand.

Abstract: A gap-clearing mechanism for attachment to a wheelchair is disclosed. The gap-clearing mechanism has a lower member for attachment to the wheelchair, and an upper member spaced from and parallel to the lower member and being moveable relative thereto. The upper member has at least one support column securely attached thereto and depending therefrom. The at least one support column is slideably mounted relative to the lower member. There is a wheel assembly at a lower end of the at least one support column. The wheel assembly is moveable between a retracted position and an extended position. A wheelchair fitted with two such gap-clearing mechanisms is also disclosed.

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 transportation apparatus includes a backrest and leg support pivotably connected to a seat portion. The seat portion is slidably connected to first and second spaced apart slide rails. Each slide rail includes a plurality of telescoping members. At least one middle leg and at least one rear leg depends downwardly from the seat portion. At least one middle wheel is connected to the middle leg and at least one rear wheel is connected to the rear leg. The middle wheel and rear wheel define a middle and rear rotation axes, respectively. At least one front wheel is operatively connected to the leg support. The middle leg is movable to adjust the vertical position of the middle wheel, and the rear leg is movable to adjust the vertical position of the rear wheel. The plurality of telescoping members slide the seat portion in a substantially horizontal direction in relation to the rear rotation axis or the middle rotation axis.

Abstract: A running object includes a body, at least two drive wheels disposed on a first axle, and at least one driven wheel disposed on a second axle. The running object is capable of switching between a standing posture in which the driven wheel is suspended in the air and a stable posture in which the driven wheel is placed on the ground. The running object includes a storing device that stores a target incline pattern that chronologically describes the target incline angle of the body during a transition from the standing posture to the stable posture; a detecting device that detects the incline angle and/or the incline angular velocity of the body; a torque calculating device that calculates torque based on a deviation between the target incline pattern stored in the storing device and a detection value detected by the detecting device; and an actuator for applying the torque calculated by the calculating device to the drive wheels.

Abstract: The mobile aircraft seat-wheelchair for people requiring special assistance consists of a standard aircraft seat that includes a seat (2), two armrests (1) and a backrest (3), as well as wheels (7) attached on the chassis (11), a legs rest (13), a handle (16), a motor mechanism (6) for its motion, control panels (4,5), a secure locking mechanism (8,9) for its locking on the aircraft cabin floor (15), and inputs (10) for the electrical connection between aircraft systems and access buttons (14) of the aircraft seat-wheelchair The mobile aircraft seat-wheelchair can be used by disabled people and assistants ail the way through, from the car park of a departing airport up to the pick up point of the arrival airport, including intermediate steps like boarding ramps, jet ways, lifts, shuttle uses, ambilifts, and within the aircraft cabin during flight. In the last case, it can be used by able-bodied passengers too, if there is no disabled passenger in the flight.

Abstract: A wheelchair propulsion and braking system (10) includes at least one clutch engagement disk rotatably couplable to a wheelchair frame (14). The clutch engagement disk (32) includes a gear (38) that is rotatable with the clutch engagement disk (32), and a drive chain (40) disposed around the gear (38). A drive wheel (50) is rotatably attachable to a wheel (22) of the wheelchair (12), and operatively attachable to the drive chain (40). The system also includes at least one lever arm (60) that is rotatably couplable to the wheelchair frame (14). The at least one lever arm (60) includes a handle (62) operatively coupled to an upper end (64) of the lever arm (60). The handle (62) is oriented in an accessible position during use. A pair of calipers (70) is operatively coupled to each lever arm (60), and engageable with the at least one clutch engagement disk (32). An actuator (80) is operatively coupled to the handle (62) to actuate the calipers (70), and to engage the clutch engagement disk (32).

Abstract: A wheelchair construction has an undercarriage with lateral struts, a rear axle and a seat. A pair of connection adapters are connected with the lateral struts and the rear axle, and have a circular arc-shaped portion. A pair of seat supports are connected with the seat, and have a circular arc-shaped portion which mates with, is received in, and is supported by the circular arc-shaped portion of the connection adapters to facilitate selected angular shifting of the seat supports relative to the connection adapters for adjusting the tilt angle of the seat.

Abstract: Systems and methods are described for obtaining and acting upon information indicative of circulatory health and related phenomena in human beings or other subjects.

Abstract: This invention touches the planetary gear type transmission which is comprised of a pair of single planetary gear rows are combined, and a carrier of one side and a ring gear of the other side are integrated, and a housing of a transmission is formed with the help of two carriers which operate as an input side and an output side, respectively. The transmission work is implemented by controlling the each sun gear which is rotatably installed at the fixed center shaft to engage or disengage with said center shaft or by controlling an integration and a disintegration of two sun gears. This invention gives the planetary gear type transmission a compact size and a light weight because the carrier plays a role for the housing. The center shaft can be engaged and disengaged with the body of the vehicle.

Abstract: A seat (14), particularly but not exclusively for a wheelchair, comprises a bottom rest (13, 60), a back rest support (18) rotatable relative to the bottom rest about an axis of rotation (100); and a back rest (22) slidably mounted on the back rest support and moveable therealong to vary its position relative to the bottom rest. The back rest is kinematically linked to the bottom rest such that the back rest moves nearer to the axis of rotation as the angle between the back rest support and the bottom rest increases.

Abstract: A collapsible support structure for use with a wheeled or non-wheeled chair includes a plurality of pivotally connected rigid poles which are parallel to one another in a collapsed position. Stretchable tension straps are strung on the poles to provide tension therebetween when in an erected position. A first collapsible assembly includes a front hub and four struts pivotally connected thereto. A second collapsible assembly includes a rear hub and four struts pivotally connected thereto. The hubs are slidably mounted on a spar. Four legs are pivotally connected to the spar and respectively to one of the struts. A collapsible seat is connected to first and second seat poles each having first and second telescoping segments, each pivotally connected respectively to one of the struts. Two arm poles are respectively pivotally connected to the first segments and to two back poles, which are respectively pivotally connected to each second segment.

Abstract: A seat supporting assembly (24) for supporting a seat (18), the assembly comprising a base (25) including a substantially elongated guiding rod (58), a seat support (36), a seat support-to-base linking member (56) pivotally coupled to the seat support (36) and sliding on the base guiding rod (58), a substantially elongated tilting member (60) having a guiding groove (66) and being pivotally attached to the seat support (36) and to the base (25). An actuating assembly (44) is coupled to the base (25) and includes a motion transmitting member (68) mounted within the guiding groove (60).

Abstract: According to the invention, the wheelchair is characterised in that it includes means to incline the whole seat structure, and inclining means that are interposed between the chassis and the lifting means and that include at least: a base (65) that is attached to the chassis (1) and that oscillates around a more-or-less horizontal axis, and on which the lifting means are fitted, and a mechanical assistance means that is interposed between the base (65) and the chassis (1) and that is designed to allow modification of the slope of the whole seat structure by rotation of the base (65).

Abstract: A manual propulsion mechanism for wheelchairs utilizes a lever pivotally mounted to the hub of each rear wheel such that the wheelchair user can propel the chair with push/pull movements of the levers. Forward and reverse propulsion directions are accomplished by a system of one-way reversible clutches contained in the propulsion wheel hubs which also allow the levers to be operationally disconnected such that the chair can freewheel. Operator control of direction shifting is through twisting motions imparted to the grip handles of the propulsion levers. In a preferred embodiment, improved ergonomics for propulsion direction changes are made possible by an improved short excursion clutch shifting mechanism that reduces the angle of arc through which the operator must twist the grip handle to effect the direction change. This allows the operator to retain a comfortable, stable grip on the grip handle while simultaneously propelling and controlling direction of movement.

Abstract: The invention concerns a wheelchair (1) comprising: a chassis (2) supporting a seat; two rear wheels (4) of large diameter, mobile relative to the chassis between a low position for normal use and a raised position for climbing a staircase, an auxiliary drive mechanism for climbing a staircase.

Abstract: A system for providing a wheelchair user access to forward, neutral and reverse movement while maintaining a continuous grip, silent operation, and allowing for small rotational movements of the wheelchair wheel to be easily made. The system includes a one-way bearing which is attached to a wheelchair wheel such that the center of the one-way bearing is coaxial with the wheelchair wheel axle, a drive axle mounted through the center of said one-way bearing, and a drive rod.

Abstract: A wheelchair comprising: three or more ground-engaging wheels; and a user seat, the user seat forming a structural member or monocoque on which the ground-engaging wheels are supported; wherein at least one of the wheels is connected to the seat by a support member, the length of the support member being adjustable during use. Also provided is a wheelchair or other wheeled vehicle, wherein at least one ground-engaging wheel is connected to a pivotable hub, and the said wheel is adjustable. Also provided is a wheelchair, wherein a ground-engaging wheel on each side of the wheelchair is provided with a brake. Also provided is a wheelchair or other wheeled vehicle in which one or more ground-engaging wheels are provided with ratchet means. A coupling arrangement for releasably joining two structural members is also provided. Also provided is a wheelchair including a rear castor with a detent mechanism.

Abstract: A gear shift pertaining to a hub of a wheel with a quick lock. The hub has a gear which is supported round a shaft with an outer end and an inner end. The inner end of the shaft is suspended via a suspension device on a vehicle. The quick lock includes a rod which runs in a cylindrical hole which is concentric within and with the shaft and a catch which locks the wheel with the shaft to the suspension device. The gear shift includes the shaft, the rod and a control, all so adapted that the rod has a neutral position relative to the shaft and wherein a movement, relative to the shaft, of the rod from the neutral position in a direction from the outer end of the shaft towards the inner end of the shaft disengages the catch so that the wheel together with the shaft can be locked to and released from the suspension device.

Abstract: A wheel assembly having multiple small rotatable wheels mounted laterally thereon whereby lateral movement as well as forward and backward movement is provided. A pair of the wheel assemblies are utilized on a hand-propelled wheelchair that can be moved laterally as well as in the standard forward-reverse motion. The wheelchair comprises a frame, one or more axles, a pair of main wheels rotatable on the one or more axles, and a plurality of small rotatable outer wheels positioned laterally on the main wheels.

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 according to one embodiment is provided with a frame and a seat assembly that is movable in elevation relative to the frame. The frame has a seat hinge mounted thereto, and is rotatably coupled to left and right wheels. The seat assembly has a side member hingedly coupled to the seat hinge and a seat back hingedly coupled to the side member such that the seat back can be maintained at a constant angle relative to the frame when the side member pivots about the seat hinge and moves the seat assembly between multiple elevations. The wheelchair also comprises a lockable spring hingedly mounted to the frame and to the seat assembly; the spring is lockable at multiple positions thereby locking the seat assembly at the multiple elevations. This spring can be sufficiently elastic to suspend the seat assembly and absorb shock at each of the locked multiple elevations.

Abstract: A frame (1) that is similar to that of a conventional wheelchair with footrest (2), pushing handles (3) and provided with a pair of rear driving wheels (4) and another pair of front guiding wheels (5), a wheelchair with armrests (6) that slide in a longitudinal front-back direction over guide rails (7), with each guide rail provided with a rack (9) that through a pair of pinions (10-10?) transmit movement to a transverse axle (11) to which an indented corona (15) is keyed, which through a transmission (16) allows a turning movement of the rear wheel (4) corresponding to the chair, through a set of pinions (18), so that with an alternating movement of the user's arms (13), acting over the armrests (6), a turning movement is created for the rear wheels (4) of the chair, allowing a noticeable improvement in the comfort of the user.

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 frame member that includes a first metallic tube member, a second metallic tube member, and a tubular composite member. First and second end portions of the composite member extend into the first and second metallic tube members. The first and second end portions of the composite members are secured to inner surfaces of the first and second metallic tube members. The end portions of the tubular composite members may be connected to the inner surfaces of the metallic tube members in a variety of different ways. For example, the end portions may be forced radially outward into engagement with the inner surface of the tube members to secure the end portions to the inner surfaces of the tube members.

Abstract: A jointed mechanism of an electric wheelchair is disclosed. The jointed mechanism includes symmetrically arranged front caster assemblies, symmetrically arranged rear caster assemblies, drive wheel assemblies, and a main chassis assembly. The front caster assemblies are bushed to the main chassis assembly and the rear caster assemblies respectively. The rear caster assemblies are fixed to the drive wheel assemblies by pivot arm plate assemblies and bushed to the main chassis assembly and the rear caster assemblies to construct a four-bar linkage, which allows the electric wheelchair to always have contact with the ground with all wheels and to adjust the center of gravity to maintain balance automatically, even when the electric wheelchair is climbing a slope or moving on an uneven surface.