Modular backrest system for a wheelchair

A backrest system for a chair for seating an individual, said chair having a seat and upright posts extending upwardly from the rear of the seat in a spaced apart, substantially parallel manner, said backrest system comprising:

• a back support adapted to be positioned generally between the posts to provide a surface against which the back of an individual rests when the individual sits on the chair seat;
• a support chassis mounted to said back support for supporting said back support at a desired incline with respect to the posts, and at a desired seat depth with respect to the seat;
• said support chassis including a pair of side plates with one side plate being adapted to be disposed between each post and said back support, and at least one horizontal tube attached to and extending transversely between said side plates across said back support;
• and
• an attachment assembly operably connected to said support chassis and connectable to the posts to allow said support chassis and back support to be readily removed from or attached to the chair.

A backrest system for a chair for seating an individual, said chair having a seat and upright posts extending upwardly from the rear of the seat in a spaced apart, substantially parallel manner, said backrest system comprising:

• a back support adapted to be removably positioned between said posts to support a back of an individual sitting on the chair seat;
• a support chassis adapted to be disposed between said posts and mounted to said back support for supporting said back support at a desired incline with respect to said posts;
• and
• a two-point attachment assembly connectable to each of said posts at a desired location along each post for releasably securing said support chassis to said posts.

A backrest system for a chair for seating an individual, said chair having a seat and upright posts extending upwardly from the rear of the seat in a spaced apart, substantially parallel manner, said backrest system comprising:

• a back support adapted to be removably positioned between said posts to support a back of an individual sitting on the chair seat;
• a support chassis adapted to be disposed between said posts and mounted to said back support for supporting said back support at a desired incline with respect to said posts;
• a pair of support tubes attached to said support chassis and extending vertically therefrom in a substantially parallel, spaced apart manner;
• and
• an attachment assembly connectable to each of said posts for releasably securing said support chassis to said posts;
• said back support including a plurality of pads mounted to said support tubes at desired locations based upon support needs and proportions of the individual;
• each of said pads being movable inwardly, outwardly and laterally with respect to said support tubes and at forward and rearward inclines with respect to said support tubes to provide a support surface for the individual sitting on the seat based upon that individual's dimensions and support needs, each pad being attached to at least one of said support tubes by an elbow joint that permits inward, outward and lateral movement of said pad.

A backrest system for a chair for seating an individual, said chair having a seat and upright posts extending upwardly from the rear of the seat in a spaced apart, substantially parallel manner, said backrest system comprising:

• a back support adapted to be removably positioned between said posts to support a back of an individual sitting on the chair seat;
• a support chassis adapted to be disposed between said posts and mounted to said back support for supporting said back support at a desired incline with respect to said posts, said support chassis being movable forwardly and rearwardly with respect to said posts to allow for positioning of said back support at a desired seat depth with respect to said seat, said support chassis further including a pair of side plates disposed on opposite sides of said back support, said side plates being adapted to be disposed between said back support and said posts, each side plate having a horizontally extending slot formed therein to permit forward and rearward movement of said back support to adjust the seat depth, said support chassis further including a pair of swivel clamps mounted to said side plates having circumferentially extending slots formed therein to permit angular rotation of said back support with respect to said posts to adjust the incline of the back support;
• and
• an attachment assembly connectable to each of said posts for releasably securing said support chassis to said posts.

A backrest system for releasable attachment to a chair, the chair having a seat and upright posts extending upwardly from the rear of the seat in a spaced apart, substantially parallel manner, said backrest system comprising:

• a back support adapted to be positioned generally between the posts to provide a surface against which the back of an individual rests when the individual sits on the chair seat;
• a support chassis mounted to said back support for supporting said back support at a desired incline with respect to the posts, and at a desired seat depth with respect to the seat;
• and
• a two-point attachment assembly adapted to removably secure said support chassis to the chair, said attachment assembly being connectable to said posts at one desired point of attachment along each post.

A backrest system for a chair for seating an individual, comprising:

• a pair of support tubes connectable to a rear of said chair and extendable vertically therefrom in a substantially parallel, spaced apart manner;
• and at least one back support pad attached to at least one of said support tubes at a desired location based upon support needs and proportions of an individual sitting in the chair;
• said pad being coupled to said support tube by at least one elbow joint, said elbow joint permitting inward, outward and lateral movement of said pad, said elbow joint including a first member having a first end with a first opening extending therethrough and a second end attached to said support tube, said elbow joint further including a second member having a first end coupled to said first end of said first member via a swivel attachment assembly and a second end attached to said pad via a ball and socket joint, said swivel attachment assembly including a post extending outwardly through an opening formed in the first end of the second member and through the first opening of the first member, and a retaining device attached to said post for preventing said post from becoming dislodged from said first and second members and permitting said first member to rotate freely about said post, said elbow joint further including a locking mechanism for selectively preventing rotation of said first member with respect to said second member when said elbow joint is positioned at a desired orientation.

A backrest system for a chair for seating an individual, comprising:

• a pair of support tubes connectable to a rear of said chair and extendable vertically therefrom in a substantially parallel, spaced apart manner;
• and at least one back support pad attached to at least one of said support tubes at a desired location based upon support needs and proportions of an individual sitting in the chair;
• said pad being attached to said support tube by a ball and socket joint that permits forward and rearward incline of said pad with respect to said support tube;
• said ball and socket joint including a spherical ball including a first section and a second section, a socket having a spherical cavity formed therein that is sized to receive at least a portion of said ball, and means for radially moving said first section of said ball inwardly or outwardly with respect to said second section of said ball, said ball being in an unlocked position permitting rotation of said ball in said socket when said first section is in abutment with said second section of said ball, said ball being in a locked position preventing movement of said ball in said socket when said first section is moved radially outwardly from said second section into engagement with said socket.

A backrest system for a chair for seating an individual comprising:

• a pair of support tubes connectable to a rear of said chair and extendable vertically therefrom in a substantially parallel, spaced apart manner;
• a plurality of support pads attached to said support tubes to support a back of an individual sitting on the chair seat, said back support pads including a first pad to provide a first tier of support for the sacral region of the back of the individual seated in the chair, a pair of pads including a second and a third pad to provide a second tier of support for the lumbar region of the individual's back, said second pad being attached to one support tube at a desired location and the third pad being attached to the other support tube at a location corresponding to that of the second pad, and a fourth pad attached to the support tubes to provide a third tier of support for the mid-thoracic region of the individual's back, and a fifth pad mounted on said support tubes to provide a fourth tier of support for the upper thoracic region of the individual's back;
• a headrest pad mounted on said support tubes to provide a fifth tier of support for the head of the individual;
• and
• a plurality of pad covers with one pad cover removably positioned around each support pad.

A backrest system for a chair for seating an individual, said chair having a seat and upright posts extending upwardly from the rear of the seat in a spaced apart, substantially parallel manner, said backrest system comprising:

• a back support adapted to be removably positioned between said posts to support the back of an individual sitting on the chair seat, including a plurality of pads with each pad being positioned to support a particular region of the individual's back, each pad having a backing plate and an insert attached to a forwardly presented face of said backing plate against which the region of the back of the individual can rest;
• a support chassis adapted to be disposed between said posts and mounted to said back support for supporting each pad of said back support at a desired location with respect to the individual's back;
• and
• a two-point attachment assembly connectable to said posts at one desired point of attachment along each post for releasably securing said support chassis to said posts.

A ball and socket joint comprising:

• a substantially spherical ball including a first section and a second section formed by passing a cutting plane through the ball, said first section having a maximum circumference corresponding to that of a small circle of the ball, said second section having a maximum circumference corresponding to that of a great circle of the ball, said first and second sections having spherical outer surface areas terminating in juxtaposed planar base surfaces defined by said cutting plane, said planar base surfaces having diameters corresponding to a diameter of the small circle of the ball;
• a socket having a cavity formed therein that is sized to receive at least a portion of said ball;
• and
• said first section of said ball being movable inwardly towards and outwardly away from said second section of said ball, said ball being in an unlocked position permitting rotation of said socket with respect to said ball when the planar base surface of said first section is in abutment with the planar base surface of said second section of said ball;
• said ball being in a locked position preventing movement of said socket with respect to said ball when said first section is moved outwardly away and spaced from the planar base surface of said second section and the spherical outer surface of said first section is in engagement with the cavity of said socket.

A ball and socket joint comprising:

• a ball including a first section and a second section, said ball having an opening extending radially through said second section;
• a socket having a cavity formed therein that is sized to receive at least a portion of said ball;
• and
• means for moving said first section of said ball inwardly and outwardly with respect to said second section of said ball, said ball being in an unlocked position permitting rotation of said socket with respect to said ball when said first section is in abutment with said second section of said ball;
• said ball being in a locked position preventing movement of said socket with respect to said ball when said first section is moved radially outwardly from said second section into engagement with said socket,
• said means including a threaded stud attached to said first section of said ball and extending through said opening in said second section outwardly from said socket, said stud being movable within said opening inwardly to an extended position and outwardly to a retracted position, said ball being maintained in the unlocked position when said stud is in the retracted position, said ball being maintained in the locked position when said stud is in the extended position.

A ball and socket joint comprising:

• a substantially spherical ball including a first segment and a second segment, said second segment having a threaded opening extending radially therethrough, said first and second segments being formed by passing a cutting plane through the ball, said first segment having a maximum circumference corresponding to that of a small circle of the ball, said second segment having a maximum circumference corresponding to that of a great circle of the ball, said first and second segments having outer surface zones terminating in juxtaposed planar base surfaces defined by said cutting plane, said planar base surfaces having diameters corresponding to a diameter of the small circle of the ball;
• a socket having a cavity formed therein that is sized to receive a portion of said ball;
• a threaded stud attached to said first segment of said ball and adapted to be engaged by and disposed in the threaded opening of the second segment, said stud extending outwardly from said socket, said stud being movable within said opening inwardly to an extended position and outwardly to a retracted position, said stud moving said first segment of said ball into abutment with said second segment when said stud is in the retracted position to permit said ball to rotate freely in said socket, said stud moving the planar base surface of said first segment of said ball outwardly away and spaced from the planar base surface of said second segment and the outer surface zone of the first segment into engagement with the cavity of said socket when said stud is in the extended position to prevent rotation of said ball in said socket.

A ball and socket joint comprising:

• a ball including a first section and a second section, said first section of said ball being constructed from a nylon material, said second section of said ball being constructed from a strong engineering plastic material;
• a socket having a cavity formed therein that is sized to receive the first section of said ball and at least a portion of the second section of said ball;
• and
• said first section of said ball being movable inwardly towards the second section of the ball and outwardly away from said second section of said ball into engagement with the socket, said ball being in an unlocked position permitting rotation of said socket about said ball when said first section is in abutment with said second section of said ball;
• said ball being in a locked position preventing movement of said socket with respect to said ball when said first section is moved outwardly away from said second section into engagement with said socket.

An elbow joint comprising:

• a first member including a first end having a first opening extending therethrough;
• a second member having a first end coupled to said first end of said first member;
• a swivel attachment device coupling said first member to said second member, including a post extending outwardly through an opening formed in the first end of said second member and through said first opening in said first member, and a retaining device attached to said post for preventing said post from becoming dislodged from said first opening and permitting said first member to rotate freely around said post;
• a locking mechanism for selectively preventing rotation of said first member with respect to said second member when said elbow joint is positioned at a desired orientation.

A ball and socket joint comprising:

• a substantially spherical ball including a first section, a second section, a threaded opening extending radially through said second section of said ball;
• a socket having a cavity formed therein that is sized to receive a portion of said ball, said socket including a base having said cavity formed therein, and a C-shaped bracket secured to said base when said ball is positioned inside said cavity, said bracket having an inner edge positioned around a portion of said ball;
• a threaded stud attached to said first section of said ball and extending through said opening in said second section outwardly from said socket, said stud being movable within said opening inwardly to an extended position and outwardly to a retracted position, said stud moving said first section of said ball into abutment with said second section when said stud is in the retracted position to permit said ball to rotate freely in said socket, said stud moving said first section of said ball outwardly away from said second section into engagement with said socket when said stud is in the extended position to prevent rotation of said ball in said socket, said stud extending outwardly through said bracket and permitting limited rotation of said ball in said socket when said stud is in the retracted position, said inner edge of said bracket engaging said ball when said stud is in the extended position to prevent rotation of said ball in said cavity.