Adjustable side frame and wheelchair with adjustable side frame

An adjustable side frame for a wheelchair comprises an upper side frame and a lower side frame. The upper and lower side frames are connected together by first and second connections. The first and second connections are each structured to be axially and pivotally displaceable relative to the upper and lower side frames to permit the elevation and angle of the upper side frame relative to the lower side frame to be adjusted.

BACKGROUND
 Wheelchairs are well known forms of transportation that increase the
 mobility of the physically impaired. Wheelchairs are typically relatively
 small, single-person conveyances that generally comprise a seat supported
 by a frame which, in turn, is supported by two oppositely disposed drive
 wheels and front casters.
 In order to meet the needs of the physically impaired, wheelchairs should
 be easily and readily adapted to fit the profile of various wheelchair
 occupants. Moreover, it is often preferable that wheelchairs accommodate
 component parts unique to the wheelchair occupant. While meeting the needs
 of the physically impaired, wheelchairs must continue to accommodate both
 ambulatory and recreational travel.
 Conventional wheelchairs are typically custom-built to address the needs of
 the wheelchair occupant. However, custom-built wheelchairs are generally
 costly. Moreover, ordering and custom building a wheelchair commonly
 results in an undue delay in delivering the wheelchair to the wheelchair
 occupant.
 Adjustable wheelchairs are an alternative to custom-built wheelchairs.
 Adjustable wheelchairs typically include side frames having various frame
 tubes that are in part adjustably connected together. Adjustable
 connections may come in the form of slidable and pivotally displaceable
 connections. Such connections are often limited in their application and
 frequently require adjustments to multiple components where an adjustment
 to a single component will accomplish the desired result.
 A need exists for a wheelchair that is easily adaptable to suit the needs
 of a wheelchair occupant without imposing an undue delay in the delivery
 of the wheelchair on the wheelchair occupant. A simple yet dependable,
 low-cost alternative to the more costly conventional custom-built
 wheelchairs is desired.
 SUMMARY
 The invention is directed to an adjustable side frame that satisfies the
 foregoing as well as other needs. An adjustable side frame for a
 wheelchair comprises an upper side frame and a lower side frame. The upper
 and lower side frames are connected together by first and second
 connections. The first and second connections are each structured to be
 axially and pivotally displaceable relative to the upper and lower side
 frames to permit the elevation and angle of the upper side frame relative
 to the lower side frame to be adjusted. The invention is also directed to
 a wheelchair in combination with the adjustable side frame.
 Various objects and advantages of this invention will become apparent to
 those skilled in the art from the following detailed description of the
 preferred embodiment, when read in light of the accompanying drawings.

DESCRIPTION
 Referring now to the drawings, there is illustrated in
 FIG. 1 a wheelchair 110 comprising a pair of laterally spaced side frames
 112 (only one side frame 112 is shown). The side frames 112 are supported
 on a supporting surface S by front wheels or casters 114 and rear drive
 wheels 116. A laterally extending seat panel 118 and seat back 120 are
 supported between the side frames 12. The side frames 121 can further
 support opposing armrests (not shown) and footrests 122.
 The present invention is an adjustable side frame 112 comprising an upper
 side frame 124 and a lower side frame 126. The upper side frame 124
 comprises a front frame tube 128 and an upper frame tube or seat tube 130.
 The lower side frame 126 comprises a lower frame tube 132 and a rear frame
 tube 134.
 The upper side frame 124 and the lower side frame 126 are connected
 together by a front connection 136 and a rear connection 138. An
 intermediate connection 140 can form a part of the upper side frame 124.
 The intermediate connection 140 can be located between the front frame
 tube 128 and the seat tube 130.
 The upper side frame 124 is preferably L-shaped in construction. The front
 frame tube 128 shown comprises an upper portion, generally indicated at
 142, and a lower end 144. An elbow 146 generally defines the upper portion
 142. The elbow 146 has a rear end 148. The seat tube 130 comprises a front
 end 150 and a rear end 152. The rear end 148 of the elbow 146 can be
 connected to the front end 150 of the seat tube 128 by the intermediate
 connection 140.
 The lower frame tube 132 of the lower side frame 126 shown comprises a
 front end 154 and a rear portion 156. The rear frame tube 134 comprises an
 upper end 158 and a lower portion 160. The rear portion 156 of the lower
 frame tube 132 shown is connected to the lower portion 160 of the rear
 frame tube 134 by an elbow 162. Although the lower frame tube 132 shown is
 provided with a plurality of offsets 164 and 166 and thus, is non-linear
 in shape, it should be understood that the lower frame tube 132 can be
 substantially straight or linear in shape or can have any other suitable
 shape.
 The front end 154 of the lower frame tube 132 of the lower side frame 126
 is connected to the front frame tube 128 of the upper side frame 124 by
 the front connection 136. The rear end 152 of the seat tube 130 of the
 upper side frame 124 is connected to the rear frame tube 134 of the lower
 side frame 126 by the rear connection 138.
 According to one embodiment of the invention, the front connection 136 can
 have a front portion 168 that is axially or substantially vertically
 displaceable relative to the front frame tube 128 along the line A--A and
 a rear portion 170 that is pivotally displaceable relative to the front
 frame tube 128 along the line B--B. The rear connection 138 similarly can
 have a front portion 172 that is pivotally displaceable relative to the
 rear frame tube 134 along the line C--C and a rear portion 170 that is
 axially or substantially vertically displaceable relative to the rear
 frame tube 134 along the line D--D. The intermediate connection 140
 enables the front frame tube 128 to be pivotally displaceable with respect
 to the seat tube 130 along the lines E--E and F--F.
 As shown in FIG. 2, the front portion 168 of the front connection 136 and
 the rear portion 170 of the rear connection 138 each can be comprised of a
 slidable member, such as the tube clamp 176 shown, which is slidably
 engageable with the front and rear tubes 128 and 134 (shown in FIG. 1),
 respectively. The tube clamp 176 can have radially extending tabs 178 with
 a hole 180 in each tab 178. The tabs 178 can be spaced apart so as to form
 a yoke 182 between the tabs 178.
 The rear portion 170 of the front connection 136 and the front portion 172
 of the rear connection 138 each can include a tongue 186 and a hole 188
 through the tongue 186. A plug 190 can extend axially or longitudinally
 from the tongue 186. The term "longitudinal" is understood to mean from
 front to back of the wheelchair 110. The plug 190 of the front connection
 136 can be insertable into the front end 154 of the lower frame tube 132
 of the lower side frame 126 (shown in FIG. 1). Likewise, the plug 190 of
 the rear connection 138 can be insertable into the rear end 152 of the
 seat tube 130 of the upper side frame 124.
 The tongue 186 of each connection 136 and 138 is insertable into one of the
 respective yokes 182. With the holes 180 and 188 in the tongue 186 and
 tabs 178 coaligned, a fastener, such as the hex cap screw 192 shown, can
 be inserted into and through the holes 180 and 188. A lock nut 194 can
 threadably engage the hex cap screw 192. The tube clamp 176 can be tightly
 clamped about the front frame tube 128 and the rear frame tube 134 by
 tightening the lock nut 194 tightly onto the hex cap screw 192. Moreover,
 tightening the lock nut 194 onto the hex cap screw 192 tightens the tongue
 186 in the yoke 182 formed between the tabs 178.
 By loosening the lock nut 194 of the front and rear connections 136 and
 138, the front and rear connections 136 and 138 can be axially displaced
 respectively along the lines A--A and D--D (shown in FIG. 1) to
 correspondingly raise and lower the upper side frame 124 relative to the
 lower side frame 126. Moreover, the tongue 186 of the front and rear
 connections 136 and 138 can be pivotally displaced respectively along the
 lines B--B and C--C (also shown in FIG. 1) relative to the yoke 182 of
 each connection 136 and 138 by loosening the lock nut 194 to permit the
 angle .phi. of the seat tube 130 (shown in FIG. 1) to be adjusted relative
 to the rear frame tube 134.
 An alternative connection 222 is shown in FIG. 8. This connection 222
 comprises vertically spaced index holes 224 in the rear frame tube 134. A
 pair of laterally spaced tabs 226 (only one of which is shown) extends
 from the rear end 152 of the seat tube 130. The tabs 226 are provided with
 longitudinally extending slots 228. A yoke 230 is formed between the tabs
 226. The yoke 230 is dimensioned and configured to receive the frame tube
 134 in such a manner that the slots 228 in the tabs 226 coalign with
 desired index holes 224 in the frame tube 134. When the slots 228 are
 aligned with the desired index holes 224, a fastener (not shown) can be
 used to connect the frame tube 134 in the yoke 230 between the tabs 226,
 and thus, releasably connect the seat tube 130 to the rear frame tube 134.
 It should be understood that a similar connection could be substituted in
 the place of the front connection 136. In an alternative embodiment to
 that shown in FIG. 8, alternate versions of the tabs 266, not shown, could
 be formed to wrap fully around the rear frame tube 134. In such a case,
 the rear end 152 of the upper frame tube 130 could be formed with a
 horizontal slot, not shown, to accommodate the need for horizontal
 displacement as the rear connection 138 moves vertically up or down.
 Another connection 322 is shown in FIG. 9. This connection 322 comprises a
 channel 324, 326 at the interface between the seat tube 130 and the rear
 frame tube 134 and at the interface between the front frame tube 128 and
 the lower frame tube 132. The channel 324, 326 would preferably be located
 on the rear frame tube 134 and the front frame tube 128, as shown in the
 drawings. Axial displacement of the rear frame tube 134 and the front
 frame tube 128 would be accomplished by a fastener or lock, such as an
 internal locking sleeve or set screws. A pivot joint 328, 330 would
 accommodate angular displacement of the seat tube 130 and the lower frame
 tube 132.
 The intermediate connection 140, as shown in FIG. 3, is comprised of a
 first portion 196 and a second portion 198. The first portion 196 can be
 comprised of a pair of spaced tabs 200 forming a yoke 202 between the tabs
 200. The tabs 200 can be provided with coaligning holes 204. The tabs 200
 can extend axially from a plug 206. The plug 206 can be insertable into a
 frame tube, such as the rear end 148 of the elbow 146 (shown in FIG. 1) of
 the front frame tube 128 (shown in FIG. 1) of the upper side frame 124
 (shown in FIG. 1).
 The second portion 198 of the intermediate connection 140 can be comprised
 of a tongue 208 having a hole 210 therein. The tongue 208 can extend
 axially from a plug 212. The plug 212 can be insertable into the front end
 150 of the seat tube 130 (shown in FIG. 1) of the upper side frame 124
 (shown in FIG. 1). The tongue 208 can be insertable into the yoke 202
 formed between the tabs 200 of the first portion 196 of the intermediate
 connection 140. With the holes 204 and 210 coaligned, a fastener, such as
 the hex cap screw 214 shown, can be inserted into and through the
 coaligning holes 204 and 210. A lock nut 216 can be threadably engageable
 with the hex cap screw 214. By tightening the lock nut 216, the tongue 208
 can be tightened in the yoke 202. By loosening the lock nut 216, the first
 and second portions 196 and 198 of the intermediate connection 140 can be
 pivotally displaced relative to one another along the lines E--E and F--F
 (shown in FIG. 1), to permit the angle .theta. of the front frame tube 128
 and the seat tube 130 to be adjusted.
 Alternatively, the plug 206 can be insertable into the front end 150 of the
 seat tube 130 (shown in FIG. 1). Alternatively, the plug 212 can be
 insertable into the rear end 148 of the elbow 146 (shown in FIG. 1) of the
 front frame tube 128 (shown in FIG. 1) of the upper side fame 124 (shown
 in FIG. 1).
 As shown in FIG. 4, the present invention can include a telescopic lateral
 support assembly 242 for supporting a lateral strut (not shown) and
 interconnecting the seat tube 130 to the lower frame tube 132 to aid in
 supporting the side frames 112. The telescopic lateral support assembly
 242 can include an outer tube 246 and an inner tube 248, which are
 slidably engageable with one another. The outer tube 246 and the inner
 tube 248 can be vertically supported by the side frames 112, such as
 between the upper frame tube 130 and the lower frame tube 132, as shown.
 The telescopic lateral support assembly 242 shown is expandable and
 collapsible along the lines G--G to permit displacement of the upper frame
 tune 130 relative to the lower frame tube 132.
 The telescopic lateral support assembly 242 is preferably pivotally
 attached to at least one of the side frames 112, such as to the lower
 frame tube 132, as shown in the drawings, by a pivotal attachment 251. The
 pivotal attachment 251 can include a tube clamp 252 that includes a
 substantially U-shaped member 254. The U-shaped member 254 is preferably
 structured and dimensioned to receive the lower frame tube 132. Saddle
 washers 256 (shown in hidden line) can be provided between the legs 258
 (only one of which is shown) of the U-shaped member 254 and the inner tube
 248 of the telescopic lateral support assembly 242. Holes (shown in hidden
 line but not referenced) in the legs 258 of the U-shaped member 254, the
 saddle washers 256, and the inner tube 248 of the telescopic lateral
 support assembly 242 are adapted to coalign to receive a fastener 260. The
 fastener 260 can be loosened to permit the pivotal attachment 251 to pivot
 or can be tightened to prevent the pivotal attachment 251 from pivoting
 along the lines H--H.
 In an alternate embodiment, not shown, the lateral support assembly 242 can
 be pivotally attached to the lower side frame 132 through connection to a
 slot, not shown, in the lower side frame 132 or in a block or bracket,
 both not shown, mounted onto the lower side frame 132. In yet another
 alternate embodiment, not shown, the lower end of the lateral support
 assembly could be comprised of a yoke or clamp, both not shown, for
 connection to the lower frame tube 132. The lower frame tube 132 could be
 adapted with a series of holes, not shown, for connection with the yoke or
 clamp.
 In operation, a pair of side frames 112 (only one of which is shown)
 according to the invention are arranged so as to be laterally spaced. As
 illustrated in FIG. 1, the side frames 112 are supported on a supporting
 surface S by opposingly disposed front wheels or casters 114 and rear
 drive wheels 116. Note that the elevation of each rear drive wheel 116 is
 preferably substantially fixed, or releasably fixed, relative to a lower
 side frame 126. In this way, the lower side frame 126 is held in a
 substantially fixed position, or at a substantially fixed elevation,
 relative to the supporting surface S. Thus, the lower frame tube 132 and
 the rear frame tube 134 are held in a substantially fixed elevation
 relative to the supporting surface S.
 The laterally spaced side frames 112 can support a seat panel 118 and a
 seat back 120. The seat panel 118 preferably, in turn, can support a seat
 cushion, such as the cushion 236 shown in FIG. 1, or the cushion 238 shown
 in FIG. 5. The side frames 112 of the present invention can be easily
 adjusted to adjust the elevation of the seat panel 118 to accommodate
 cushions of varying thickness or customize the height of the seat tube
 130, as will become more apparent in the description that follows.
 The side frame 112 can be independently adjusted at each of the connections
 136, 138 and 140 and 251. As shown in FIG. 5, the elevation of the seat
 panel 118 can be raised, such as from the position shown in FIG. 1, by
 sliding the front connection 136 downward in the direction of the arrow A'
 relative to the front frame tube 128 of the upper side frame 124, and by
 sliding the rear connection 138 upward in the direction of the arrow D'
 relative to the rear frame tube 134 of the lower side frame 126.
 Similarly, the outer tube 246 can be raised upward in the direction of the
 arrow G' relative to the inner tube 248. Conversely, the elevation of the
 seat panel 118 can be lowered back to the position shown in FIG. 1 by
 sliding the front connection 136 upward relative to the front frame tube
 128 of the upper side frame 124 and the rear connection 138 downward
 relative to the rear frame tube 134 of the lower side frame 126.
 Similarly, the outer tube 246 can be lowered downward relative to the
 inner tube 248.
 As shown in FIG. 6, the rear end 172 of the seat panel 118 can be lowered
 or tilted back by sliding the rear connection 138 downward in the
 direction of the arrow D" relative to the rear frame tube 134 and
 pivotally displacing the front frame tube 128 in the direction of the
 arrow B' relative to the lower side frame 126 and the seat tube 130 in the
 direction of the arrow C' relative to the rear frame tube 134. Conversely,
 the front end 218 of the seat panel 118 can be raised to tilt the seat
 panel 118 (or the seat tube 130) rearward or back by sliding the front
 frame tube 128 upward relative to the front connection 136 and pivotally
 displacing the front frame tube 128 relative to the lower side frame 126
 and the seat tube 130 relative to the rear frame tube 134. Note the
 telescopic lateral support assembly 242 is permitted to expand and
 contract as well as pivot as the upper side frame 124 is displaced
 relative to the lower side frame 126.
 Alternatively, by lowering the rear connection 138 in the direction of the
 arrow D" and pivotally displacing the seat tube 130 in the direction of
 the arrow C' at the rear connection 138 and in the direction of the arrow
 E' at the intermediate connection 140, the seat tube 130 can be tilted
 rearward. This adjustment can be accomplished without substantially
 varying the elevation of the footrests 122. Conversely, the rear
 connection 138 can be raised relative to the rear frame tube 134 and the
 seat tube 130 can be pivotally displaced in a direction opposite to the
 arrow E' relative to the front frame tube 128 at the intermediate
 connection 140 to tilt the seat tube 130 forward.
 It should be understood that, where an intermediate connection 140 is
 provided, the front connection 136 could be a rigid connection, such as a
 welded connection (not shown). When a rigid front connection 136 is
 employed, the vertical displacement of the rear connection 138 may be
 limited. To increase the vertical displacement of the rear connection 138,
 it may be desirable to shift the seat tube 130 longitudinally along the
 line K--K (shown in FIG. 5). This may be accomplished by allowing the
 fasteners 192 and 214 to fit loosely in the holes 180, 188, 204 and 210
 through which the fasteners 192 and 214 are inserted.
 As shown in FIG. 7, the rear end 172 of the seat panel 118 can be raised or
 tilted forward by sliding the rear connection 138 upward in the direction
 of the arrow D' relative to the rear frame tube 134 and pivotally
 displacing the front frame tube 128 in the direction of the arrow B"
 relative to the lower side frame 126, and the seat tube 130 in the
 direction of the arrow C" relative to the rear frame tube 134. Conversely,
 the front end 218 of the seat panel 118 can be lowered or tilted forward
 by sliding the front frame tube 128 downward relative to the front
 connection 136 and pivotally displacing the front frame tube 128 relative
 to the lower side frame 126 and the seat tube 130 relative to the rear
 frame tube 134.
 The alternative connection 222 illustrated in FIG. 8 can be adjusted by
 removing a fastener (not shown) and by positioning the yoke 230 about the
 frame tube 134 with the slots 228 in the tabs 226 coaligning with desired
 index holes 224 in the frame tube 134.
 It should be understood that an adjustable side frame according to the
 invention could include a first connection and a second connection. At
 least one of the connections should be axially displaceable relative to a
 portion of the side frame 112 to permit the elevation of the opposing
 front or rear ends 111 and 113 (generally indicated in FIG. 1) of the
 upper side frame 124 to be adjusted. This, in turn, permits the elevation
 of the front and rear ends 218 or 172 of the seat panel 118 to be
 adjusted. The other connection should be pivotally displaceable to permit
 the angle between the upper side frame 124 and a lower side frame 126 to
 be adjusted. Either the front or rear connections 136, 138 can be axially
 displaceable with respect to a portion of the side frame 112, so long as
 at least one of these connections 136 or 138 is axially displaceable.
 Obviously, if the front or rear connections 136, 138 are axially
 displaceable, the elevation of the front and rear ends 111 and 113
 (generally indicated in FIG. 1) of the upper side frame 124 can be
 adjusted. If only the rear connection 138 is axially displaceable, either
 the front or intermediate connection 136 or 140 can be pivotally
 displaceable. However, if only the front connection 136 is axially
 displaceable, the rear connection 138 should be pivotally displaceable.
 If desired, a third connection can be provided. In this embodiment, the
 first and second connections, namely, the front connection 136 and the
 rear connection 138, can be axially and pivotally displaceable relative to
 a portion of the side frame 112. This permits the elevation of the front
 and rear ends 111 and 113 (generally indicated in FIG. 1) of the upper
 side frame 124 to be adjusted. This, in turn, permits the elevation of the
 front and rear ends 218 and 172 of the seat panel 118 to be adjusted. The
 third connection, namely, the intermediate connection 140, permits the
 elevation of the rear end 172 of the seat panel 118 to be adjusted without
 adjusting the elevation of the footrests 122.
 It should be understood that the sliding connection (that is, the tube
 clamp 176) and the incrementally adjustable connection (formed by the
 cooperative engagement of the yoke 230 and a portion of the side frame
 112) are described for illustrative purposes. Other forms of connections
 may be used which permit the elevation of portions of the side frame 112
 to be adjusted relative to other portions of the side frame 112. Moreover,
 other pivotally displaceable connections may be used. For example,
 portions of the side frame 112 may bend.
 Another connection between the frame parts, such as the upper frame tube
 130 and the rear frame tube 134, is to have a channel, not shown, at the
 interface of the two tubes. The channel could be located on the vertical
 tube member, is the rear frame tube 134, and the rear end 152 could be
 adapted to be slidably engaged within the channel. The rear end 152 could
 be locked in place to fix the vertical position within the channel by an
 expandable internal locking sleeve, not shown, by set screws, not shown,
 or by any other means. The pivot joint of the existing connections would
 accommodate the angular displacement.
 In accordance with the provisions of the patent statutes, the principle and
 mode of operation of this invention have been explained and illustrated in
 its preferred embodiment. However, it must be understood that this
 invention can be practiced otherwise than as specifically explained and
 illustrated without departing from its spirit or scope.