Note: Descriptions are shown in the official language in which they were submitted.
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'rhe present invention relates to mobility aids.
With the steadily increasing geriatric population and
the subsequent number oE geriatric care facilities, there has
been an increasing awareness of rapid emotional and physical
deterioration of their residents due to, among other things, a
loss of their independence. A large portion of these residents
spend extended periods of time confined to their beds or chairs,
and thereby need constant assistance rom attending nurses to
satisfy their everyday needs.
This loss in independence is not only seen as a cause
or discomfort to the patient and shorter life span, but also
results in su~stantially high costs, associated with the large
skilled labour force needed to provide daily care.
It would therefore be desirable both to the patients
and the adminis-trators of the facilities in which they are
resident, to provide as much independence as possible to the
patients. A significant factor to independence is the mobility
o~ the patient, which is conventionally provided by wheelchairs
and rigid frame structures commonly known as "walkers".
Although providing a certain de~ree of mobility to the
patients, there are several disadvantages associated with such
mobility aidinq devices. Conventional wheelchairs are bulky and
provide a convenience only to those patients with a relatively
high degree o arm strength. ~rhose patients who have lost
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strength in their arms must again demand assistance from the
attendan-ts to move from one location to another.
Conventional walkers appear in two forms, one of which
re~uires the patient to displace the structure forwardly before
each step is made and is satisfactory only to those patients with
sufficient strength in both the legs and the arms.
Alternatively, walkers a~e available providing bodily
support to the patients. However, such devices are often large
and bulky and require the patient to be entrapped within the
structure, resulting in a mobility aid which, although assisting
the patient, is conspicuous and therefore detrimental to the
patients emotional well-being.
Accordingly, it is -the object of the present invention
to provide a novel form of mobility aid.
Briefly stated, the invention involves a mobile
support device for a handicapped person and rollable along a
reaction surface, the mobile support device comprising:
f~rst and second substantially parallel planar ~rame
sections oriented in spaced relationship, each of said frame
sections having a lower portion;
a back support portion spannin~ the region and coupled with
the first and second rame portions;
a seat spanning the region and centrally disposed above said
lower portions; and
a wheel assembly mounted on said lower portions so as to
engage the reaction surface, said wheel assembly including a
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pair of front caster wheels, a pair of rear caster wheels and a
first intermediata wheel with a fixed transverse axis of rotation
positioned interm~diate said front and rear caster wheels, each
of said caster wheels and said intermediate wheel together being
disposed such that all of said wheels have a lower most tangent
lying in a common plane.
In another aspect of the present invention there is provided
a mobile support device having an undercarriage comprising a pair
of front caster wheels, a pair of rear caster wheels and a first
intermediate wheel with a fixed transverse axis of rotation
positioned intermediate said front and rear caster wheels, each
of said caster wheels and said intermediate wheel together being
disposed such that all of said wheels havea lower most tangent
lying in a common plana and a surface disposed above said
undercarriage and arranged to support a patient.
Further features, objects and advantages of the present
invention will be evident rom the following detailed description
of praferred embodiments, given by way of example only, as seen
in the appended drawings in whlch:
Figure 1 is a perspective view of a mobility device.
Figure 2 is a side view of the mobility device, shown
in Figure 1, in another configuration.
Figure 3 is a side view of the mobility device shown in
Figure 1 in an alternate configuration.
Figure 4 is a plan view of the mobility device in
Figure 1.
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Figure 5 is a plan view of the device shown in Figure l
with an alternative portion.
Figure 6 is a partly exploded view of a portion of the
mobility device shown in Figure l.
Figure 7 is a cross-sectional view taken on line 7-7 in
Figure 6.
Figure 8 is a fragmentary perspective view of a portion
of the mobility device shown in Figure l.
Figure 9 is a perspective assembly view taken with
respect to circle 9 in Figure l.
Figure lO is a perspective ~ragmentary view o another
portion of the mobility device shown in Figure l~
Figure ll is a cross-sectional view taken on line ll-lI
of Figure lO.
Figure 12 is a perspective view of the portion shown in
Figure lO in an alternative configuration.
Figure 13 is a perspective view of the portion shown in
Figure 10 in another configuration.
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Figure 14 is a perspective view of another portion of
the mobility device shown in F.igure 1.
Figure 15 is a perspective assembly view of a portion
of an elemen-t shown in Figure 14.
Figure 16 is a partly exploded assembly view of an
alternate configuration of the portion shown in Figure 6.
Figure 17 is a frontal view of the configuration in
Figure 16.
Figure 18 is a cross-sectional view taken on line 18-18
in Figure 17.
Figure 19 is an exploded assembly view of several
components of the portion shown in Figure 18.
Figure 20 is a side view of an alternative portion of
the device shown in Figure 1.
Figure 21 is a perspective view of another alternate
portion of the device shown in Figure 1.
Figure 22 is a perspective view of an alternative
mobility device;
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Figure 23 is a perspective view of a portion of a
alternative mobility device to the device shown in Fiyure 22;
Figure 24 is a frontal view of an alternative element
of the portion shown in E'igure 23;
Figure 25 i5 a side view of the element shown in Figure
24.
Figure 26 is a perspective view of an alternative
portion of an element shown in Figure 24.
Figure 27 is a perspective view of another alterna-tive
portion of an element shown in Figure 24.
Referring now to Figures 1 to 17, a mobility device 10
is shown in the form of a chair having a frame 12 which supports
seat 14 and a back rest 16, with the seat being inclined at
approximately six degrees from the horizontal axis, and the back
rest 16 inclined 15 degrees from the vertical axis. The chair
has a pair of arms 18, 20 the former being pivotal and the
latter being retractable as will be described. A tray 22 is
mounted on the front oE the arms 18r 20 and provides a working
surface as well as a protective gate and hand grip. In addition
a carrying hamper 23 hangs Erom the arm 20 for carrying
magazines or other articles. A wheel assembly 24 is provided on
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the bottom of the chair which is con trolled by a pair of braking
handles 26 which activate a braking mechanism 28 as will be
described. A pair of adjustable foot rests 30 are mounted on
the Erame 12 as will be described, with restraint being provicled
to the user by a seat belt 32 extending from the seat. As well,
the seat is pivotable and height adjustable as will be later
explained.
The frame is formed from left and right frame sections
34, 36 both being of a "S"-shaped configuration. Each of the
left and right frame sections have a lower horizontal portion
34a, 36a to support the wheel assembly, a lower corner portion
34b, 36b to support the foot rests 30, a middle portion 34c, 36c
to support the seat 14 and back rest 16, and an upper portion
34d, 36d to support the tray 22 and also to form the arms 18, 20
of the chair~ As wellt the middle portion 34c, 36c serves as a
location for frame disassembly, as shown in Figure 3. This is
provided by way of the middle portion being formed from two
parts, a first segment, for example 34e, havin~ a swaged end of
reduced diameter for telescoping engagement with the end of a
second segment 34f.
Referring to Figure 4, each oE the arms 18, 20 is also
provided with a pair of arm rests 42, while the tray 22 is
pivotally connected to the left arm 18 and releasably positioned
on the right arm 20. As well, the lateral edges 22a of the tray
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are concave thereb~ providing suficient area for a working
surface while enabling the patient to grip the centraL region of
the tray 22 with his hands.
As is seen in Figure 9, the right arm 20 is easily
retractable, and is formed from first and second right arm
portions 20a, 20b the first portion 20a having a swaged end
region for telescoping engagement with the end of the second
right arm portion 20b. A restraint mechanism 44 is provided in
the first right arm portion 40a and is seen as a ball 44a nested
in a hole 20c and biased therein by way of a compression springl
44b with the ball extending from the hole so as to extend into a
hole 20d formed in the second right hand portion 20b.
While the right arm 20 is retractable, the left arm 18
is pivotal between a usable position and a storage position. As
seen in Figure 10, the left arm 18 has a first left arm portion
18a pivotally connected to a second left arm portion 18a at a
pivot connection identified at 45. In forming the pivot
connection 45, the end of the first left arm portion 38a is
collapsed to form a substantially "U"-shaped cross-section. As
seen in Figure 11, the first left arm portion 18a is pivotally
connected to the second let arm portion 18b by way of an
extensible pivot member 46 extending through co-axial bores 18c,
18d formed in the first and second left arm portions 18a, 18b
respectively. The extensible pivot member 46 is formed from a
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cylinder element ~6a closed at one end by a Eirst head 46b with
the other end having a bore 4~c extending there-through. A
piston ~6d is slidably engaged with the innee surface of the
cylinder element 46a and is joined to a shaEt ~6e which extends
through the bore 46c, with the free end of the shaft terminating
at a second head 46f. A compression spring 46g is located
within the cylinder element 46b to bias the piston 4~d against
the first head 46b, such that rotation of the first left arm
portion 38a causes separation thereof from the second left arm
portion 38b, and causing the pivot member 46 to extend through
the travel of the piston 46d along the cylinder element 46a
against the spring 4~g.
The pivot connection between the first and second left
arm portions 18a, 18b and pivot connection between the tray 22
and the first left arm portion 18a enables the left arm 18 to be
rotated to a convenient storing posi~ion as demonstrated in
~igures 2, 10, 12 and 13. As is shown in Figure 10, the tray 22
is first rotated to a vertical position as seen by the arrow
"A". The first left arm portion is then rotated to an upper
vertical position as seen by arrow "B". This is followed by the
tray being returned to its original position relative to the
first leEt arm portion as seen by arrow "C". Subse~uently, the
arm is rotated to a lower stored position as seen by the arrow
"D". In this manner, the configuration embodied in the left arm
18 enables the patient to store the tray thereby providing the
patient with the capability of sitting at a table, or of
accessing the chair Erom the side.
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Similarly, the first right arm portion 20a is easily
retractable by depresslng the ball 44a through the hole 20d and
subsequently removing the swaged end of the first right arm
portion 20a from the second right arm portion 20b.
Another particular feature of the chair 10 is the wheel
assembly 24 as seen in Fiqure 1 which is coupled to the lower
horizontal portions 34a, 36a of the left and right frame
sections 34, 36. Three wheels, for example wheels 48, 50, 52
are used on each of the lower horizontal portions, for example
34a, the front and rear wheels 48, 50 thereof providing a swivel
movement with respect to the lower horizontal portion 34a. The
middle wheel 52 on the other hand is constrained to rotation
about an axis perpendicular to the lower horizontal portion
34a. In this configuration, the wheels prevent lateral
displacement of the chair relative to the floor while permitting
increased stability and improved directional tracking, as well
as the ability to rotate about a fixed point.
The braking assembly 28 is shown in detail in Figure
8~ The brakes are manually controlled by braking levers 26
which extend upwardly and forwardly from slots 54 formed in the
rear of the lower horizontal portions 34a, 34b. Each of the
levers 26 are coupled to a first link 56 which is fixed to one
end of a pivot rod 58 defining a pivot axis "E", which in turn
is rotatably mounted at both ends to the horizontal portions
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34a, 34b. In this Eashion, rotation o~ one Eirst link 56 causes
rotation oE the other. The pivot rod 58 conveniently extends in
a concealed manner within a spanner member 60 joining the left
and right lower hori~ontal portions 34a, 34b.
The first link 56 is pivotally connected to one end 62a
of a second link 62 at a pivot iden-tified at "F" which extends
along the inner cavity of the lower horizontal portion 34a, with
the opposite end 62b being pivotally connected to one end 64a of
a braking link 64. The lower portion of the braking link
extends downwardly to a pivot pin 66 on which the braking link
pivots relative to the lower horizontal portion. The braking
link extends past the pivot pin and outward from a slot 6
formed in the lower region of the horizontal portion 34a.
Joined to the other end 64b of the braking link 64 is a brake
pad 69 of an arcuate shape so as to contact the floor contacting
surface 53a of the center wheel 53.
Thus, when either of the levers 26 is rearwardly
displaced, the first :link S6 rotates about the pivot rod 58
causing the second link 62 to be displaced forwardly. This in
turn causes rotation of the braking link 64 about the pivot pin
66 to engage the brake pad 69 with the floor contacting surface
53a of the wheel 53.
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In this manner, the braking assembly 28 provides
simultaneous braking of both :Left and right centre wheels 53 by
rotation of either braking lever 26. In addition, the pivot
points are selected in the first link such that the pivot point
"F" of the second link is l'over-center" with respect to the
pivot axis "E" of the pivo-t rod 58~ In this manner, the braking
assembly 28 provides a self-locking mechanism whereby the
braking lever 26 is rotated toward contact with the rear edge of
the slot 54. This corresponds to a point where the pivot point
"F" is located above axis "E", thereby causing the reaction
force, exerted by the wheel 54 and transmitted through the
mechanism 28, to maintain the lever 26 in the locked position
against the rear edge of the slot.
In an alternative embodiment, the braking mechanism 28
is capable of providing a constant light braking Eorce to the
middle wheels for a controlled substantially unaccellerated
travel down an incline. This is provided by an arcuate bracket
70 which is fixed to the lower horizontal portion 34a of the
frame adjacent to the central region of a brake lever 26. The
bracket 70 has a number of notches 70a formed therein to enable
the lever 26 to be locked in a par-ticular orientation 90 as to
provide a constant braking ~orce against the wheel 53. In this
case, the extent of rotation of the lever 26 to maintain
substantially unaccellerated travel, increases with the degree
of incline being traversed. If desired, the pivot rod 66 may be
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located on the frame 53b of the wheel rather than on the lower
horizontal portion 34a, thereby providing relatively shorter
distance of travel of the brake pad 69.
The chair is also provided with a seat 14 which is
pivotal and height adjustable by way of a height adjustment
mechanism 74 illustrated in Figures 6 and 7. The seat is
pivotally mounted via a pair of first support blocks 76 to a
tubular shaft 78, the shaft being held at each end by a second
support element 80. Adjacent the second support element 80 is a
rack element 82 of a rack and pinion arrangement, the pinion 84
being fixed to a rod 86 which extends through a slot 80a formed
in the second support element 80. Both the second support
element 80 and the rack element 82 are fixed to a transverse
frame element 88.
Positioned adjacent the second support element is a
plate element 90 having a centrally located bore 90a, through
which the rod 86 extends. In addition, a pair of guides 92
extend downwardly along the inner surface of the plate SG as to
engage with the front and rear edges 80b, 80c of the second
support element 80. Fixed to the end of the rod 86 is a knob 94
Eor rotation oE the rod 86 and accordingly the pinion 84 along
the rack element 82. The region of the rod 86 between the knob
94 and the plate 90 is threaded to engage threadably with a
release latch 96, which releasably maintains the rod 86 in
position.
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The height adjustment mechanism provides facilitated
adjustment oE the seat 14 relative to the frame 12, by way of
rotating the release latch 96 and subsequently turning the knob
94. This causes relative displacement between the rack element
82 and the pinion 84, and results in the support element 80
travelling along the guide 92.
A further mechanism is provided on the seat to dampen
sudden rotations of ~he seat relative to the shaft. In Figure
7, an air cylinder 98 is joir.ed to the central region of the
rear of the seat 14 and to a support frame 100 which includes an
arm lOOa extending rearwardly from the transverse frame member
88 and a brace lOOb joining the arm lOOa with ~he shaft 78.
In this manner, the dampening of rotation of the seat
14 is provided at any elevation thereof. With this assembly,
forward movement of the patient from the back of the seat causes
an immediate rotation of the seat 14 about the shaEt 78, with
the rotation being maintained at a slow rate by the air cylinder
98. If the patient further wishes to propel the chair along the
floor, he may do so by continuing to rotate the seat 14 until
his feet are in contact with the floor.
Another embodiment is shown in dashed lines in Figure 6
wherein the seat i5 pivotally mounted on shaft 86 by way of
support blocks 102 in lieu oE support blocks 76 and shaft 28.
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In addition, the rack element 82 and the support block 80 are
fixedly mounted to plate element 90 whi:Le shaft 86 is displaced
relative to plate 90 by extending through a slot 104, thereby
eliminatintg -the need for guides 92 and transverse frame element
88. As well, a support frame 106 is pivotally mounted on shaft
86 in lieu of support frame 100~ In this case, support frame
106 includes a support block 107 pivotally mounted on the shaft
86 adjacent each pinion element 84~ Projections 108 extend from
the upper and lower portions of support block 107, adjacent to
but not contacting the teeth of pinion 84, and extend through
the slots 80a. In this manner r support block 107 displaces in
concert with the rod 86 but does not rotate therewith.
Extending rearwardly from each of the support blocks 107 is a
frame member lOg which terminating at a junction with a frame
member lO9a which extends toward connection with the air
cylinder 98.
In yet another embodiment, a tension spring 97 is
located adjacent the air cylinder 98 to bias the seat to its
rearwardly inclined position.
In a further embodiment, a rotation limit device 99 is
located adjacent the air cylinder 98 to restrict the rearward
and forward rotation of the seat to the desired six degrees with
respect to the horizontal. The limit device includes an
elongate element 99a having a slot 99b which is connected to the
rear portion of the seat. A member 99c with a pin 99d is
coupled to the arm lOOa.
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The chair is also provided with adj~stable foot rest 30
as are shown i~l detail in Figures 14 and 15. '~he foot rest 30
includes an angular member 110 having a shaft 112 connected to
one end llOa. A foot pad 114 is pivotally connected to the
shaft 112 for movement between a horizontal position and a
ver-tical position. Magnets 116 are further provided both on the
foot pad 114 and the angular member 110 to maintain the foot pad
114 in a vertical position. The angular member is in -turn
joined to the lower corner portion 34b by a wing nut 115, and
maintained in a given orientation by a pair of interconnecting
discs 116, 113.
As seen in Figure 15, each of the discs have
transversely extending triangular teeth 120 which mesh upon
engagement of the discs 116, 113, with the disc 116 being fixed
to the angular member, and the other disc 118 being fixed to the
lower corner portion 34b. The discs 118, 116 are also
respectively provided with a pin 122 and recess 12~ as shown in
Figure 15 to enable inter-engagement of the discs within
predetermined limits, thereby preventing the foot rest 30 from
contacting the floor, thereby interEerring with the mobility of
the chair.
An alternative foot rest 125 is shown in Figure 21
wherein a right angled member 126 extends from the inter-engaged
discs 116, 119 and terminates at a crown gear elemen-t 127
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rotatably mounted circumferentially thereon. The crown gear is
threadahly engaged with a threaded rod element L28 which
includes an elongate rectangular projection 128a extending along
the shaft to engage with a complimentary recess on the inner
edqe oE the member 126. The foot rest 125 is further provided
with a pinion element 129 rotatably mounted to the right angled
member 126, teeth 126a of which are meshed with the teeth 127a
of crown gear 127. A knob 129a is also fixed to the pinion
element 129 so as to enable the user to cause rotation thereof,
which in turn causes the crown gear 127 to ro-tate and the
threaded rod 128 to be displaced relative to the member 126. In
this manner, the length of the foot rest 125 is easily
adjustable to accommodate users with different leg lengths.
An alternative to the aforementioned height adjustment
mechanism 74 of the seat is the height adjustment mechanism 129
shown ln Figures 16 to 19. In this case the seat is pivotally
mounted by a pair of first support blocks 130 to a tubular shaft
132, the shaft being held at each end by a second support block
134. The second support block 3~ is in turn mounted to a first
transverse frame member 136. Each end of the transverse frame
mernber 136 is fixed to a slider frame 13~ defined by a pair of
spaced horizontal flanges 138a, 138b and joined by a vertical
web 138c. The flanges have centrally located and co-axial bores
138d which receive a threaded shaft 14û. Threaded on the shaft
140 is a remote sprocket 142 positioned at spaced distances from
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each of the Elanges by upper and lower spacers 144~ 146. The
threaded rod is in turn held in a support Erarne 148, again
defined by a pair of horizontal flanges 148a, 148b and joined by
a vertical web 148c. In this case, each o the support frames
148 is fixed to the central region of the middle portion 34c of
the frame sections.
A chain 150 passes over each of the remote sprockets to
a central crank mechanism 152 located in the central region of
the transverse frame member. The crank mechanism comprises a
crank 154 member having an offset cranking knob 154a mounted on
a cranking arm 154b. ~he cranking arm is in turn mounted on a
shaft 156 to which a sprocket 158 is also mounted. The shaft
156 is rotatably mounted in the transverse frame member by way
of releasable mounting through a bore 136a and maintained
therein by a nut and washer 160. In this manner, rotation of
the crank arm 154b via the knob 154a causes the chain 150 to be
displaced in a manner which causes rotation of the remote
sprockets 142. By virtue of their threaded engagement with the
threaded rods 140, the sprockets 142 then upwardly displace with
respect to the threaded rods 140, thereby raising the elevation
of the seat.
Incorporated with the height adjustment mechanism 129
is an air cylinder 159 mounted at one end on the rear portion of
the seat as is shown in Figures 18 and 19. The air cylinder is
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mounted at its other end to a Erame assemb]y 161 extending
rearwardly Erom the shaEt 132 and the transverse frame mernber
136.
It should also be noted tha-t the air cylinders 98 and
159 each provide a dampening effect to both forward and rearward
locations of the seat. This dampending effect could also be
provided in one rotative sense only or be greater in one
rotative sense than in the other. Oil cylinders are also
contemplated as an alternative to the air cylinders.
Also contemplated is a height adjustment mechanism
utilizing a rack and pinion arrangement, wherein the rack
element thereof is fixed relative to the seat frame, while the
axis of pinion element is fixed on a pivot shaft displaced
relative to the seat frame. In additionr the seat may be
pivotally mounted on the pivo~ shaft.
In additionl an alternative to the aforementioned
concave edged tray 22 is shown in Figure 4 wherein the tray 162
is incorporated with one arm pad~ to provide an increased arm
support particularly for patients having suffered from a stroke
or from other causes, resulting in little strength in one arm.
Also contemplated is the use of a restraint bar in place of the
tray.
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Also contemplated Eor ad~usting the height of the seat
is the use Oe a split seat 164 as shown in Fi~3ure 20. The split
seat 164 inclucles a rear section 168 which is mounted to the
middle portion 34c of the frame by way of a pair of flanges 168
depending from each side of the rear section 166, which slidably
engage with a frame plate 170 mounted on the middle portion
34c. A series of holes 170a, 170b are located near the front
and rear ends respectively o~ the frame plate 170 and are
in-line with holes 168a, 168b located in the front and rear ends
respectively of the flange 168 so as ~o receive adjustment pins
172. A front section 174 is hingeably mounted to the rear
section 166 and has on each side a downward projection 176 which
abuts a cam element 178.
A second embodiment of the mobility device is shown in
the form of a s-tand-up walker 200 in Figure 22. The walker
includes a frame 202 which supports a seat 204 pivotal between
horizontal and ver~ical positions and a back rest 206. The
support includes a releasable restraint bar 208 which assists in
supporting the user as will be described. A wheel assembly
similar to that in the aforementioned embodiment, and identified
at 210 is located in the lower end of the frame for mobility
while a pair of outriqgers 212 extend transversely from the
frame and adjacent to the wheels as will be described.
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In addition, the stand up walker 200 rnay also include a
braking mechanism in accordance with braking rnechanisrn 28 in the
a~orementioned embodiment and, in which case, is equipped with
length adjustable arms 213.
The frame structure is formed from left and right frame
sections 214, 216, each of an "S"-shaped conEiguration, to form
lower, middle and upper horizontal frame segments 214a, 214b,
214c and 216a, 216b, 216c respectively. The lower frame
segments combine with a spanning member 218 which extends
between the rear region of the lower segments 214a, 216a to form
a base, while the upper segments 214c, 216c combine to form the
left and right arms of the walker 200. Joining each of the
lower and middle segments is a first vertical spanner 214d~ 216d
formed from a pair of telescoping elements which, joined by a
bolt configuration identified at 220, so as to provide a walker
200 which may be disassembled.
Disassembly is also provided by a second vertical
spanner 214e, 216e formed from a pair of telescoping elements
which, joined by a bolt configuration shown at 221 may be either
disassembled or length adjusted.
The restraint bar 208 is pivotally connected to the
left arm 214c, while the opposite end of the restraint bar is
coupled to the right arm 216c, by way of a releasable latch 222.
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Projecting longi~.udinally erom each end oE the lower
frame segments are collars 224 which enga~e with the right
angled ends 212a of rectangular outriggers 212. Joining the
ri~ht angled ends -thereof is a body member 212b. The collars
224 are further provided with a bore 22~a which receives a pin
to fix the outrigger 212 with the lower surface of the body
member having an incremental spacing from the floor surface, for
example one half inch. In this manner, the outrigger 212
provides a support against inadvertent tipping of the walker
200. As seen in Figure 22, the seat 204 is pivotally connected
to a pair of brackets 226 immediately below the back rest 206,
which in turn is mounted on a fixed cross panel 228.
The seat 204 provides a suppor~ for the patient in a
partial sitting position in which, while gripping the arms 214c,
216 or the restraint bar 208 may propel the walker 200.
Alternatively, the seat may be stored in a vertical position
enabllng the patient to walk with the support of the walker in a
standing position, with further support being provided by a
harness 230.
The harness 230 includes a belt 232 which extends
around the central region of the user, and has a releasable
buckle in the rear portion thereof. The belt 232 is joined to
the arms 214c, 216c by way of four expandable belts 234, which
are coupled to the arms 214c, 216c by way of releasable brackets
236.
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An alternative to the fixed outrigger is shown in
Figure 23, wherein the pillS are omitted from the collars so as
to enable the outrigyer 212 to rotate therein. In addition, a
first link 240 is pivotally connected between a remote point on
the frvnt right angled member shown at 242 and a pivot point in
the central region of a second link 244. The second link in
turn is pivotally coupled to the vertical spanner 214d and has
at its remote end, a handle 244a enabling the patient to rotate
the second link upwardly in the direction of the arrow
identified at "G". In this manner, the outrigger is easily
retracted to a stored position, enabling the walker to pass
through a doorway.
A further alternative to the fixed outrigger is an
automatically extendable outrigger 250 as shown in Figures 24
and 25. The automatic outrigger 250 is formed from a first
housing 252 and a second housing 254, the second housing 254
being pivotal relative to the first housing 252, which is
secured to the lower frame segment 214a. Located on the first
housing 252 is an activation rod 256 which is oriented at one
end 256a in close proximity with the floor surface, and is
slidably engaged within brackets 258 extending near each end
thereof from the first housing 252~ The other end 256b o the
activation rod 256 is engaged with a flrst latch 258 which is
pivotally mounted to the first housing 252 and engages a catch
260 formed on the second housing. The second housing 254 is
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tubular and has one end 254a through which outwardly extends a
deploy rod 262, which is slidably engaged with the inner surface
of the second housing. ~he deploy rod is also biased to an
outwardly extended position by way of a spring 263, also within
the second housing and engaged with a boss 262a formed in the
central region oE the deploy rod 262. The other end 254b of the
second housing has an aperture formed therein, through which the
other end of the deploy rod 262b outwardly extends in a stored
position as shown in Figure 21. The end of the deploy rod is
deEined by a circumferential groove 262c which engages with the
finger 264a of a second latch 264, pivotally mounted to the
second housing 254 and biased against the groove by a spring 266.
The second latch 264 is activated by way of an abutment
rod 268 which is positioned in a bracke-t 270 formed on the first
housing 252 and adjusted to the required extension therefrom by
way of a set screw 272, so as to engage the other end oE the
second latch 264 upon rotation of the second housing 254 with
respect to the first housing 252 under the biasing force of a
coil spring 276 joined therebetween.
In this manner, inadvertent rotation of the frame 12
relative to the floor cau~es the floor to engage with the
activating rod 256, resulting in the release of the first latch
258. This causes the second housing 254 to quickly rotate under
the force of the coil spring 276 to a lateral outward position,
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733
- 25
~ausing the second latch 264 to engage with the abutment rod 26
thereby releasing the deploy rod 262 from within the second
housi.ng 254. In this manner, the deploy rod 262 acts as an
additional stabilizer to increase the lateral stability and
prevent further rotation of the frame 12 relative to the floor.
In addition, the angle through which the second housing 254
rotates and the relative length of the second housing 254 and
the deploy rod 262, are choosen such that in the extended
position, the frictional force between the inner wall of the
second housing 254 and the second deploy rod ~62 provides a
binding reaction force, thereby enabling the housing and the
deploy rod to function as a unitary s~pport member against the
force exerted by the patient against the frame 12 of the walker.
When the frame is returned to its stable position, the
binding force between the deploy rod 2~2 and the inner surface
of the second housing 254 is immediately reduced to enable an
attendant to easily retract khe outrigger 2`50 to its stored
pos.ition as shown in Figure 22.
In an alternative embodiment as is shown in Figure 26,
the deploy rod 278 is formed with a "T"-shaped outward end,
providing additional stability while at the same time
distributing the force exerted on the deploy rod in its extended
position.
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In another alternative embodiment as shown in Figure
27, a deploy rod 280 has a "T"-shaped end, with one of the
transversely extending arms 280a having a arm 280b extending
inwardly at right angles to the transverse arm 280a. In
addition, the inwardly extending arm is oriented at an angle o
with respect to the axis of deploy rod 230, angle o
corresponding to the angle in which the deploy rod 280 is
located relative to the horizontal in the outwardly extended
position. In this manner the deploy rod 280 provides further
support to the outrigger in its extended position located
adjacent the front or rear wheel.
In addition, any number of outriggers may be located on
the side of the walker. For example a convenient combination
involves the placement of an outrigger adjacent each wheel.
Alternative arrangements are also considered for the
harness 230 including six or more belts 23~ to provide further
support to the userO Also contemplated is the use of different
types of belts 230 such that the front belts have a different
spring rate constant than the rear belts, thereby providing
easier flexibility of the harness in one direction than in the
other. For exarnple, the use of a higher spring constant in the
rear pair of belts enables the user to flex the harness in the
rearward direction which preventing the user to 1ex easily the
harness in the Eorward direction, thereby supportin~ the user
against falling forward.
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