CA1269608A - Wheelchair - Google Patents

Abstract

ABSTRACT
An improved wheelchair formed of a frame, two pairs of support wheels for the frame, and a seat portion rockably connected to the frame and normally maintained in a generally horizontal alignment when the chair is unoccu-pied by bias springs that permit the seat to rock about its rockable connection while the frame and wheels of the chair are completely stationary.

Description

~:6~6~

The presen~ inVention xelates i~ general to wheelchair assemblies emplo~ed to provide tra~sportation for invalids or the aged, an~ more specificall~ relates to such assemblies that are adapted to ~ulfill a special need the user may have.
Wheelchairs are used by a surprisingly large percentage of the people living in the world. They are used not only by the physically handicapped, but also by inval-ids that, either for reasons of age or other problems, no longer haYe the capabil`ity for walking or at least for walk-ing any great distances.
The common wheelchair is formed from a frame sup-portèd`by a large pair of main wheels and a smaller pair of steering caster wheels normally located forwardly of the drive wheels. A seat is fixed with respect to the frame so that a user is provided support while being transported about in the chair. However, such chairs are relatively un-comfortable for long usage, especially for- the aged.
Other different wheelchair designs are known in ~0 the prior art for providing various specific functions. For example, in United States Patent NoO 3~953,054 a six-wheeled chair is disclosed. The chair is supposed to be more maneu-verable and has a seat that can be varied in height and in-clination. Also, the patent indica~es in an oblique fashion ~5 that there is some type of spring suspension associatedwith the seat th~at permits the seat "to rotate against the spring action around a horizontal axis between the hocks and a vertical projection of the crutch of the occupant." The chair is designed to be supported by only four of its six wheels at a time and the occupant of the chair can control which wheels will be supported by leaning back in the seat or leaning forward. Apparently, the spring suspension re-ferred to above is used to facilitate the operator's sup-port wheel control.
Although U. S. Patent No, 3,953,054, as previous-ly pointed out, refers to a spring suspension in use with a seat, the patent does not show or describe any structure "` ' ' - ' " ' ' -- -- . , .

- 2 -formin~ the spring suspension. Obviously, the patent is not designed to provide a wheelchair with a rocking seat.
If the occupant a~tempted to rock in the chair, the chair would alternate from being supported by the rear four wheels to ~he front four wheels in a somewhat jarring rashion that would not only be uncomfortable but would re-quire a relatively large amount of body action that would be tiring.
Another example of an unusual wheelchair con-struction is shown in United States Paten~ No. 4,310,167.Such patent discloses a wheelchair with an articulated chassis that permits an operator to change the center of ~ravity of the chair to vary its stability according to conditions encountered by the operator. Also, the chair lS includes a shocX absorber and spring means that positivelv maintain a subframe and seat frame assemblies of the chair in a predetermined relationship but permits the subframe and seat frame assemblies to articulate relative to one another for increasing comfort when traversing rou~h ground.
~0 It is clear from the disclosure of the U. S.
Patent No. 4,310,167 that it is neitner adapted to nor does it show or describe the use of a wheelchair having a rock-able seat. In United States Patent No. 3,100,638 a baby rocker that has a rockable seat is shown and described.
~5 The baby rocker is designed to permit a baby to rock as much as it pleases and to provide a rotating motion of the wheels of the rocker while the seat is rocked to enhance the at-traction of the device for the baby. Although the device disclosed in UO S. Patent No. 3,100,638 has a rockable seat, the patent is obviousl~ directed to a totally different field of art than the wheelchair a~t and in no way would lead one skilled in the axt to the present invention.
The object of the present invention is to provide an improved wheelchair having a rockable seat that permits a user to enjoy the rocking motion of the seat similax to that provided by a normal rocking chair while the frame and wheels of the ~yheelch~a~r are held in a completely stationary position.

,. . ..

-- 3 ~

The present invention therefore provides an improved wheelchair that permits a user to rock while seated in the chair, said wheelchair comprising:
(a) a frame having opposie spaced apart rigid side members that are connected together by cross braces;
(b) a pair of main wheels each of which is connected to one of said frame side members, and at least one of which serves as a driving wheel for the chair;
(c) at least one caster wheel pivotally connected with said frame;
(d) a seat having at least two ri~id spaced apart support rails and a support platform attached to and extending between said rails;
(e) rockable connection means between said support rails of said seat and said side members of said frame to permit said seat to rock about a horizontal axis transverse to said side members while the frame and wheels are completely stationery; and (f) bias means to normally maintain said seat in a generally horizontal alignment when the chair is unoccupied.
In a first preferred embod.iment of the present invention, the frame is formed from opposite, spaced apart, rigid side members that are connected togethex by cross braces. The support wheels for the frame include a pair of main wheels, each of which is connected to one of the frame side members and at least one of which serves as a driving whePl for the chair, and a pair of caster wheels pivotally connected with the frame forwardly of the main wheels.
The seat includes two rigid spaced apart support rails and a support platform connected to and extending between the rails. The rockable connection of the seat extends between the side members of the frame and the support rails of the seat to permit the seat to rock about a horizontal axis traverse to the side members. The .

~2~

- 3a -rockable connection means i5 provided by a yoke member that is fixed to at least one of said side members and said seat support rails, and is rockably connected to the other of said side members and said rails. In a second preferred embodiment of the present invention, the rockable connection means is formed by two rigid generally V-shaped support members, each attached to one of the support rails and one of the frame side members, with the vertices of the support members being pivotally attached thereto, Although both preferred embodiments illustrate a non-motorized wheelchai.r, it should be apparent to those skilled in the art that the present invention can be employed with all types of wheelchairs including, but not limited to, motorized, racing and sport v~rsions.
In the drawings:
Figure 1 is a slde perspective of a first pre-ferred embodiment of an lmproved wheelchair of the present invention that includes a rockable seat;
Figure 2 is a side view of the wheelchair shown in Figure 1 with the main wheels thereof represented by dotted lines for purposes of clarity;-Figure 3 is an enlarged fragmentary view of the wheelchair of Figure 2 showing a locking lever assemblythat forms part of the present invention; and Figure 4 is a view similar to that of Figure 2, but sho~ing a second preferred embodiment of the present invention.
Referring now to the drawings and with reference first to Figure 1, a first preferred embodiment of an im-proved wheelchair of the present invention is shown general-ly at 10~ The wheelchair 10 includes a frame assembly 11, a seat assembly 12, a pair of main wheels 13 and a pair of caster wheels 14. Preferably, the frame assembly 11 is constructed of high strength, lightweight tubular members to provide a chair that is durable but yet is light enough that it can be handled relatively easily.
The frame assembly 11 is formed o~ upright side members 17 along each side of the chair 10. Each side mem-ber is typically formed of front and rear upright members 18 and 19 respectively, and upper and lower horizontal tubular members 20 and 21 respectively joined toge~her in a generally rectangular conf.iguration. Preferably, the side fxame members 17.are joined together by cross braces 23 and 24 (not shown in Figure 1 for purposes of clarity) and are pinned to one anotker at 25 to peXmi~ the wheelchair 10 to be folded to bring the side members 17 adjacent to one another, as is well known in the art, Each side frame member 17 journals one of the main wheels 13 and provides a downwardly opening vertically aligned pivot socket 29 to mount the caster wheels 14 for-wardly.of the main wheels 13~ Each of the caster wheels 14 ' - , .

is carried on a horizontal axle 26 mounted in an inverted ~-shaped yoke ~7~ Preferably, foot assemblies 28 are at-tached in cantilever fashiGn to the upright tubular mem-bers 18 to support the feet and legs of a user.
The seat assembly 12 is extended transversely be-tween the side frame members 17 and is formed from tubular side support members 32 and a pliable sea~ member 33 formed of leather fabric, nylon or the like that is attached to and e~tends between the support members 32. The seat assem-bly 12 may also have an armrest 35 associated with each of the side support members 32 and a backrest 36 secured to the rear ends of the side support members 320 As shown in Figures 1 and 2, the seat assembly 12 is rockably connected to the side frame members 17 by means of yoke mounts 40 that each have a lower end 41 fixed to one of the upper horizontal tubular members 20 and an upper U-shaped end 42 that is pinned to one of the side support members 32. Thus, the seat assembly 12 has a rocking ac-tion freedom of movement with respect to the frame assembly 11. To normally maintain the seat assembly 12 in a hori-æontal alignment, biasing means 43 in the form of spring assemblies are connected between the front and rear ends of the horizontal members 20 and side support members 32.
Although the biasing means 43 are shown as springs herein, it should be well recognized in the art that a wide vari-ety of other resilient members or other types of biasing members other than springs can be employed as the means 430 Preferably, the wheelchair 10 includes a locking assembly 48 (best shown in Figure 3) that serves to fix the seat assembly 12 in a horizontal alignment when the user desires as during travel. of the chair 10~ The lock-ing assembly 48 is formed of a locking lever 49 having a lower end 50 that is pinned to one of the side frame hori-zontal members 20 at 50a and an upper end 51 that has a forwardly.facing notch 52~ The lever 49 is movable from a forward position in which it is adjacent a forward limit of movement abutment 53 and a rearward position in which it is adjacent a locking stud 540 As the lever 49 is moved rearwardly, the pin connection 50a allows sufficient pla~ between the lever 49 and the member 20 to move the upper end 51 of the lever 49 outwardly from the member 32 to move past the stud 54.
When ~he lever 49 is in its rearward position, the locking stud 54 that extends out~lardly from one of the side support members 32 is received in the notch 52 so that the lever 49 supports the seat assembly 12 from pivotal movement. A biasing spring assembly 56 is connected be-tween the locking lever 49 and the associated horizontal ln member 20 ~o urge the locking lever in a forward direction to maintain the engagement between the locking stud 54 and the locking lever 49 when desired. The assembly 56 also supports the forward limit of movement abutment 53.
As should be recognized in the art, a wide vari-ety of other types of rockable connections can be employedin the present invention for attachment of the seat assem-bly 12 to the frame assembly 11. For example, referring now to Figure 4, another type of such connection is shown in conjunction with a wheelchair 60 that forms a second preferred embodiment of the present invention.
The chair 60 is similar to the chair 10 except that rockable assemblies 61 are substituted for the yoke mounts 40. The rockable assemblies 61 are formed in a V-shape configuration with vertexes 62 pinned to the hori-zontal frame members 20 at 63, and upper ends 64 and 65that are respectively fixed to the front and rear ends of the side support members 32. As a result, the seat assem-bly 12 has a Ereedom of rocking movement about the pin con-nections 63. Of course, it should be noted that the rock-able assemblies 61 could be used in an inverted condition so that the pin connection 63 and point of rocking of the seat assembly 12 would be at the side support members 32.
In li~e respect, the yoke mounts 40 of the wheelchair 10 could as well be inverted~
Thus, the present invention provides a unique and improved wheelchair means that provides a comfortable sup-port for a user comparable to that of a normal rocking chair when desired. The chair may be used by persons of ~69~8 all ages (except for the very young) to provide a pleasant rockiny action. Due to the rockable connections between the frame assembly 11 and the seat assembly 12 and the resilient action of the biasing means 43, a user of the S chair 10 may sit normally in the seat 11 and with very little effort expended enjoy the rocking action of the seat assembly 12 as it rocks about its rockable connections without any movement of the wheels 13 and 14 or the frame assembly 11.

Claims (6)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An improved wheelchair that permits a user to rock while seated in the chair, said wheelchair comprising:
(a) a frame having opposite spaced apart rigid side members that are connected together by cross braces;
(b) a pair of main wheels each of which is connected to one of said frame side members, and at least one of which serves as a driving wheel for the chair;
(c) at least one caster wheel pivotally connected with said frame;
(d) a seat having at least two rigid spaced apart support rails and a support platform attached to and extending between said rails;
(e) rockable connection means between said support rails of said seat and said side members of said frame to permit said seat to rock about a horizontal axis transverse to said side members while the frame and wheels are completely stationery; and (f) bias means to normally maintain said seat in a generally horizontal alignment when the chair is unoccupied.

2. An improved wheelchair as recited in claim 1 wherein said chair further comprises means for controlling the rocking motion of said seat whereby when said means is actuated, said seat is held in a fixed position with respect to said frame.

3. An improved wheelchair as recited in claim 1 wherein:
(a) said seat platform is formed from a non-rigid material; and (b) said cross braces of said frame are foldable to permit said frame side members to be moved approximate to one another.

4. An improved wheelchair as recited in claim 1 wherein said rockable connection means each comprise yoke means extending between said frame and said seat support rails and being rigidly connected to one of said frame and said rails and having a U-shaped yoke pin connected to the other of said frame and said rails.

5. An improved wheelchair as recited in claim 1 wherein said rockable connecting means comprises two rigid, generally V-shaped support members each attached to one of said support rails and one of said frame side members, with the vertices of said support members being pinned thereto.

6. An improved wheelchair as recited in claim 1 wherein said bias means extends between and is attached to said seat support rails and said frame.