Medical Composite Technology

Everest & Jennings International, Ltd.

Robert W Lishman

Richard T Geiger

A Scott Robertson

Scott Dentino

Modular wheelchair

A chassis is provided having two longitudinal sides, one or more cross-bars between the sides, and two torsion forwardly and downwardly extending arms terminating in sleeves for holding snap-in casters. When attached to the other wheelchair components, the arms create a space therebetween and under the wheelchair seat for storage of optional items. The molded chassis may be tailored to performance specifications and is constructed from composite material, preferably by compression molding using sheet molding compound or by resin transfer molding. Shock and vibration attenuating characteristics are selectable and the chassis sides may be of one or multiple piece construction. Each longitudinal side includes two vertically extending posts for attaching a seat, the posts providing a height, seat pan angle and center of gravity adjustment mechanism for the seating system relative to the chassis. The drive wheels are attached to camber plugs which are secured within recesses in the sides. The camber plugs are interchangeable and include a variety of selected camber angles. In another aspect of the present invention, the cross-bars are of adjustable width thereby permitting the width of the chassis to be adjusted to accommodate users of different sizes, and to accommodate different sized seating systems. In an additional aspect of the invention, the chassis disassembles into two halves, the two halves connected by cross-bars of a preselected length. In one additional aspect, seat mounting rails are attached within an inner surface of the longitudinal sides. The chassis may attach a variety of seating systems, including one piece composite seats.

Molded-composite chassis for a wheelchair

A generally hollow or foam filled, light-weight wheelchair chassis is constructed from composite materials preferably by compression molding using sheet molding compound for volume production, or by resin transfer molding for the production of smaller numbers of units. Each chassis side may be formed in one or two side portions Two-portion side construction is preferred for compression, and the portions may be molded as a left segment and a right segment that are joined vertically, or as an upper segment and a lower segment that are joined horizontally. Joining may be by conventional pin and socket devices, lap joints, or tongue and groove joints. Manufacture by resin transfer molding is preferred when each chassis side is to be made in one-piece. Metallic elements may be placed into the molds prior to curing, or bonded to the chassis following curing. Reinforcing ribs may also be integrally formed with the sides, or separately formed and attached by suitable bonding or attachment techniques. The chassis sides may also be manufactured in one piece from composite materials using reinforced reaction injection molding, structured reaction injection molding, hand layup over foam techniques, and hand layup with internal pressure techniques. The manufactured composite chassis preferably has two longitudinal sides, one or more cross-bars between the sides, and two self-supporting torsion arms extending forwardly and downwardly from the chassis sides and terminating in sleeves for holding casters.

Method of construction for a composite wheelchair chassis

Seating unit for a wheelchair

A modular wheelchair that may be rapidly assembled and disassembled includes an adjustable chassis for releasably attaching a wheel module and a seating module having a detachable leg rest module. The one-piece chassis is constructed from composite materials and has hollow or foam filled longitudinal sides and cross-bars connecting the sides, and two cantilevered or trussed forwardly extending arms which connect swivel castors. The sides include mounts for adjustably attaching the seat module at a selectable center of gravity and height. The composite materials of the arms provide shock and vibration protection and further provide a space behind the arms and beneath the seating assembly for storing and attaching optional equipment. The wheel assembly includes drive wheels constructed from composite materials, smaller travel wheels for traversing narrow openings, anti-tip wheels and wheel locks. the wheels may be composite or tensioned disk wheels that may be locked by wheel locks having a spring device for automatically opening or closing the lock. The wheels are removably attached within lateral recesses in the chassis sides by interchangeable wheel axle alignment plugs which receive the wheel axle and plug into the recesses. The interchangeable plugs define a variety of angled axle chambers to provide for pre-selection of camber angles for the wheel. The seating assembly includes a frame having two longitudinal side members and at least one cross-member secured to the sides at the front and rear of the frame, side rails for adjustably mounting to the mounts on the chassis, and a seat with a forwardly pivoting back rest. A leg rest module including a foot rest is adjustably mounted to the seating module and includes a leg rest clamping mechanism for clamping the leg rest at a fixed angular orientation relative to the frame. The leg rest may be rotated substantially 90 degrees in front of the wheelchair and substantially 90 degrees to a retraction position beneath the seat. The leg rest includes independently adjustable right and left foot rest plates to enable the length of each leg to be independently accommodated, and for independently adjusting the user's ankle angle. The leg rest may be removed for double amputees.

A caster retention device is disclosed that supresses flutter or shimmy of a caster wheel and that is easily adjustable. The device includes a caster stem receiving chamber in which a bushing is disposed. The bushing receives a caster stem assembly that includes bearing elements. An adjustable locking device secures the stem assembly within the bushing and is positioned at an opening of the receiving chamber. In one embodiment the device may include first and second collars that are useful for adjusting a preload on the bearings.

Caster wheel retention device

Wheelchair

A modular wheelchair that is fully adjustable for a wide range of users in a wide range of uses includes a wheelchair chassis, a wheel assembly and a seat assembly. Drive wheels of the wheel assembly may be adjusted to have a different camber angle without changing the wheel base or the height of the wheelchair chassis. The modular wheelchair may also include a leg rest assembly that is adjustable to provide easy access to the wheelchair. The seat assembly and the leg rest assembly are each foldable so that the wheel chair may be easily stored.

A seating system is provided for a wheel chair including a chassis, two drive wheels, and two swivel mounted casters. The seating system comprises a frame which is adjustably mountable to the chassis. The frame includes two side members and at least one cross-brace member. A seat is removably mounted to the frame for seating a user. The seat may be padded, have webbing material, be sling-back, or be of molded construction. A back rest is mounted to the frame and may include a locking mechanism cooperating with the frame for locking the back rest at an adjustable upright position. A leg rest including a foot rest is adjustably mounted to the frame and includes a leg rest clamping mechanism for clamping the leg rest at a fixed angular orientation relative to the frame. The foot rest may be pivoted to adjust the ankle angle of the user.

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LaSelva Beach, CA, United States of America

Robert W Lishman