Note: Descriptions are shown in the official language in which they were submitted.
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=
HEIGHT-ADJUSTABLE CORDLESS BRAKE
CROSS REFERENCE TO RELATED PRIOR ART
IL] The present application is a continuation-in-part of United States
Patent Application No.
10/692,092 filed October 23, 2003, which is a divisional of United States
Patent Application No.
09/908,102 filed July 18, 2001, which issued as United States Patent No.
6,659,478 on December
9, 2003, which claims priority from Canadian Patent Application No. 2318028
filed September
12, 2000., all of-which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[21 The present invention relates to a wheeled walker, which can be used as
a transport chair,
and in particular to a novel braking system for wheeled apparatus.
[3.] Many persons, by reason of age or disability have difficulty in
walking without a walking
aid. Wheeled walkers or rollators are widely used by many such persons to
assist in mobility. A
wheeled walker typically has a frame mounted on four wheels and a pair of
rearwardly extending
handlebars, which the user can grip for support while walking. The user
positions himself
between the handlebars behind the walker, and pushes the walker forward. The
wheels permit
the user to roll the walker smoothly over the ground, thereby avoiding the
laborious action of
picking up and moving a non-wheeled walker in step-by-step fashion. The handle
bars can be
fitted with brake levers that when squeezed by the user, actuate some form of
wheel braking
mechanism.
H.] Wheeled walkers are routinely equipped with a seating surface that
permits the user to
rest in the sitting position. The seating surface is usually positioned
transversely between the
handlebars within the wheelbase of the walker to offer a stable platform for
sitting. In order to
use the seating surface, the user must turn around and sit down in the
rearward facing direction,
opposite to the normal direction of travel, with his feet resting on the
ground. The braking
mechanism can be fitted with a locking mechanism to maintain braking
engagement with the
wheels to prevent the walker from rolling while the user is sitting.
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[5.] While the provision of a seat to permit the user to rest is a useful
feature, it often occurs
that the user is too tired to continue walking and requires the assistance of
a caregiver to continue
travel. Conventional wheeled walkers are not adapted to support a seated user
and be pushed by
a caregiver. In particular, because the user is seated in a rearward facing
position between the
handlebars, there is very little space between the user and the caregiver,
making it difficult for
the caregiver to take walking steps without interfering with the feet of the
user. Moreover, there
is no dedicated means on conventional walkers to support the feet of the user
while in the sitting
position with the result that the feet are usually dragged across the ground
or propped up on a
frame member in an unnatural position.
[6.] There have been a number of attempts to provide a wheeled apparatus
that is useful as a
self-propelled walker and also as a caregiver propelled transport chair.
[7.] United States Patent No. 5,451,193 discloses a combined wheelchair and
walker. In the
normal walking position, the seating surface is pivoted up rearwardly toward
the seat back to
provide space between the handlebars for the user to walk. The user walks in a
forward direction
pulling the walker behind him. When the user wishes to sit, the seating
surface can be flipped
down. There is no provision to permit the walker to be pushed by a caregiver.
Indeed, the patent
discloses that a third party must pull the seated user backwards by pulling on
the seat back.
[8.] United States Patent No. 5,451,193 discloses a combination wheelchair
and walker.
While the user or the caregiver can push the apparatus from behind as a
conventional walker or
transport chair, in order to assume the seated position, the user must walk
around to the front of
the apparatus, which manoeuvre can be difficult for a physically challenged
person.
[9.] United States Patent No. 5,605,345 discloses a wheeled apparatus for
use both as a
walker and a wheelchair. The design has rearward facing handlebars to permit
the apparatus to
be used as a wheeled walker. The design also has a bi-directional seating
arrangement. When the
seat is placed in the rearward facing position, it permits the person using
the device as a walker
to rest in a seated position by turning around and sitting down in the
rearward facing direction
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with his feet resting on the ground. When the seat is placed in the forward
facing position, the
apparatus can be used as a conventional wheelchair. The wheelchair design is
conventional in
that it has large rear wheels with hand-rings that permit the wheelchair to be
propelled by the
occupant or rearward facing handles to permit the wheelchair to be pushed by a
caregiver.
[101 While the design disclosed in United States Patent No. 5,605,345 offers
significant
advantage, it is not well adapted for use as a walker. Because it is based on
a conventional
wheelchair design, it is heavy and bulky, making it difficult to manoeuvre in
confined locations.
Furthermore, the bi-directional seating arrangement uses a frame mounted link
arrangement,
which cannot be practicably adapted to a light walker design. Because the seat
back is pivoted to
the seat base, the vertical rise of the seat back is limited and accordingly
offers only lower back
support. Furthermore, when positioned in the walker mode, the seat back
obscures the user's
view of the ground directly in front of the walker.
[11.1 Conventional walkers have been equipped with handle bar mounted braking
system
actuators that permit the user to manually apply braking force when walking or
to lock the brakes
to permit the user to safely assume a seated position. For example, one such
system is disclosed
in United States Patent No. 5,279,180, and relates to a cable braking system.
The actuating
mechanism uses a connecting lever to pull the cable when the brake lever is
raised to a braking
position or depressed to a locked position.
[12.] Thus, there remains a need for a walking aid that offers all of the
functionality of a
conventional wheeled walker and can be readily converted for use as a
transport chair.
[13.] Cable type braking systems are commonly used on walkers, which have
height adjustable
handlebars. In such a case, the flexible cable accommodates the variable
length between the
brake handle actuator and the wheel mounted braking element. However, cable
type braking
mechanisms have a number of deficiencies. In particular, the cables require
rather precise and
periodic adjustment to maintain effective braking action. Moreover, because
the cables are
routed from the brake handle actuator to the wheels outside of the frame and
require some slack
to accommodate height adjustability, the resulting loop or bight in the cable
is prone to catching
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or snagging on other objects, a deficiency which is particularly problematic
in the case of a
folding style walker that is transported in the trunk of a car.
114.1 A simple solution for eliminating the brake cable is to provide a solid
rod linkage
between the brake-handle actuator and the braking element that extends down
through the two
telescoping parts of the height-adjustable handle bar. Unfortunately, the
solid rod linkage
prevents a pin, bolt or screw from passing through both the telescoping parts
of the height-
adjustable handlebars, which would normally provide a secure, but adjustable
means for locking
the telescoping parts together. Since safety is the ultimate priority for
these types of devices, it is
important that the height adjustable handlebars are securely reconnected after
adjustment. One
solution to this problem is disclosed in United States Patent No. 6,283,484
issued September 4,
2001 in the name of MalmstrOm, which provides an adjustable brake rod inside
the telescoping
handlebars. Unfortunately, the MalmstrOm device relies on a single friction
screw, which
extends through the outer telescoping parts of the handle bars into frictional
engagement with the
inner telescoping brake rods, to hold the two telescoping parts of the
handlebar and the two
telescoping parts of the brake rod together. This system relies heavily on the
strength of the user,
and on the durability of the frictionally engaged materials. Frequent
tightening and loosening by
elderly or otherwise disabled users make this type of system susceptible to
accidental slippage,
and therefore unacceptably dangerous.
11.5.1 An object of the present invention is to overcome the shortcomings of
the prior art cable
and cordless based systems by providing a cordless brake actuating system for
a height
adjustable handlebar that enables a locking screw, pin or bolt to extend
through both parts
thereof.
SUMMARY OF THE INVENTION
[16.] Accordingly, the present invention relates to a height-adjustable,
manually-actuated brake
device for use with a wheel mounted on a height-adjustable frame, which
includes a lower
telescopic member, an upper telescopic member, and a locking pin for extending
through both
the upper and lower telescopic members, comprising:
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a brake mounted on the lower telescopic member;
a manually-engageable brake actuator for actuating the brake;
an upper leg extending from the brake actuator through the upper telescopic
member, the upper leg including a gap for receiving the locking pin, which
extends therethrough;
a lower rod adjustably connected to the upper leg and extending through the
lower
telescopic member, the lower rod including a slot for receiving the locking
pin, which extends
therethrough; and
an adjustable connector for locking the upper leg and lower rod together at
any
one of a plurality of positions.
[17.1 Another feature of the present invention relates to a mobility aiding
device comprising:
a frame including front and rear support members, the rear support members
having upper and lower telescoping members;
a locking pin for extending through the upper and lower telescoping members
for
locking the relative position thereof;
front wheels mounted on the front support members;
rear wheels mounted on the rear support members;
a moveable brake mounted on the frame for hindering the rotation of one of the
front or rear wheels;
a manually-engageable brake actuator for actuating the brake;
an upper leg extending from the brake actuator through the upper telescopic
member, the upper leg including a gap for receiving the locking pin, which
extends therethrough;
a lower rod adjustably connected to the upper leg and extending through the
lower
telescopic member, the lower rod including a slot for receiving the locking
pin, which extends
therethrough; and
an adjustable connector for locking the upper leg and lower rod together at
any
one of a plurality of positions.
BRIEF DESCRIPTION OF THE DRAWINGS
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[18.] FIG. 1 is a front right perspective view of the walker/transport chair
of the present
invention with the back rest in the walker position;
[19.] FIG. 2 is a right side view of the walker/transport chair of the present
invention with the
back rest in the walker position;
[20.] FIG. 3 is a plan view of the walker/transport chair of the present
invention with the back
rest in the walker position;
1214 FIG. 4 is a right side view of the walker/transport chair of the present
invention with the
back rest in the transport chair position;
1224 FIG. 5 is a plan view of the walker/transport chair of the present
invention with the back
rest in the transport chair position;
[23.] FIG. 6 is a right side view of the back rest extension arm;
[24.] FIG. 7 is a left side view the back rest extension arm;
[25.] FIG. 8 is a perspective view showing the manner in which the backrest is
connected to
the extension arms;
[26.] FIG. 9 is a front view of the cross-bar member;
[27.] FIG. 10 is a top plan view of the cross-bar member;
128.1 FIG. 11 is a right side view in partial section of the cross-bar member
connection details;
[29.] FIG. 12 is a side view of the inside of the right brake housing half;
[30.] FIG. 13 is a side view of the inside of the left brake housing half;
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[31.] FIG. 14 is a left side view of the brake actuator slide;
[32.1 FIG. 15 is a rear view of the brake actuator slide;
[33.] FIG. 16 is a right side view of the brake actuator slide;
[34.] FIG. 17 is a side view of the inside of the right brake housing half
showing the position
of the brake actuator slide;
[35.1 FIG. 18 is a left side view of the brake lever;
[36.1 FIG. 19 is a right side view of the brake lever;
[37.] FIG. 20 is a side view of the inside of the left brake housing half
showing the brake lever
in the neutral position;
[38.1 FIG. 21 is a side view of the inside of the left brake housing half
showing the brake lever
in the depressed brake locking position;
[39.] FIG. 22 is a side view of the inside of the left brake housing half
showing the brake lever
and the brake actuator slide in the neutral position;
[40.] FIG. 23 is a side view of the inside of the left brake housing half
showing the brake lever
and the brake actuator slide in the raised brake actuating position;
[41.1 FIG. 24 is a side view of the inside of the left brake housing half
showing the brake lever
in the depressed brake locking position;
[42.] FIG. 25 is a right side view in partial section of the internal brake
actuating mechanism of
the present invention;
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[43.] FIG. 26 is a perspective view of the brake wire clamp;
[44.] FIG. 27 is a right side view, in partial section showing the brake shoe
connection details;
[45.] FIG. 28 is a perspective view of the brake shoe;
[46.] FIG. 29 is a side view of the brake shoe showing the position of the
friction member;
[47.] FIG. 30 is a perspective view of the friction member; and
[48.] FIG 31 is an exploded side view of a second embodiment of the internal
brake actuating
mechanism;
[49.] FIG 32 is an isometric view of the upper brake leg of Fig. 31;
[50.] FIG 33 is a side view of the upper brake leg of Fig 32;
151.1 FIG 34 is a side view of the lower brake rod of Fig. 31;
[52.] FIG 35 is a side view of the lower brake rod of Fig. 34; and
[53.] FIG. 36 is cross sectional view of the connection for the lower end of
the lower brake rod
of Figs. 34 and 35.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[54.] Referring to Figures 1 to 3, there is shown a perspective view of a
rollator or
walker/transport chair 10 in the walker configuration. Walker/transport chair
10 has a pair of
forward leg members 12, a pair or rearward leg members 16, and a U-shaped
transverse seat
support member 20. Front leg members 12 are fixedly secured at their upper
ends to front leg
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brackets 22, and rear leg members 16 are fixedly attached at their upper ends
to rear leg brackets
26. Front leg brackets 22 are pivotally attached to rear leg brackets 26 at
pivot pins 30. In the
open or operative position shown in FIGS. 1 to 3, abutment surfaces 32 at the
upper ends of front
leg brackets 22 engage the forward lower edge of seat support member 20, when
forward leg
members 12 are in the open and weight bearing position. Front leg brackets 22
permit the front
leg members 12 to be folded toward rear leg members 16 in order to collapse
walker/transport
chair 10 into a more compact configuration, e.g. for placement in the trunk of
a car.
1554 Walker/transport chair 10 is locked in the open position by means of lock
rod 73, which
engages projections 75 on front leg brackets 22. Handle 77 is rotatably
mounted about
transverse seat support member 20 for moving lock rod 73 out of engagement
with projections
75. Handle opening 36 is provided in seating surface 34 to provide easy access
to handle 77.
[56.] Seating surface 34 is horizontally supported at its forward edge 90 by
transverse seat
support member 20 and provides a stable seating platform. Seating surface 34
is pivotally
attached to transverse seat support member 20 such that it can be flipped to a
vertical position by
pulling up on rear edge 71. This position is particularly useful when the user
wishes to move as
far forward as possible, for example when reaching ahead of the
walker/transport chair 10 to
remove objects from a cupboard.
[571 Front leg members 12 are stabilized by crossbar member 68, which extends
horizontally
between front leg members 12 and is fixedly secured to the bottom ends of
front leg members 12
at end fittings 40. Front wheels 38 are mounted on front fork assemblies
having a vertical axle
shaft carried in a bearing assembly (not shown) in each end fitting 46 for
rotation about the
vertical axis to permit front wheels 38 to caster for ease of steering
walker/transport chair 10.
[58.] Rear wheels 42 are carried at the lower ends of rear leg members 16 on
rear fork
assemblies 44. Rear fork assemblies 44 are fixedly connected to the lower ends
of rear leg
members 16.
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[59.] Push handle assemblies 50 are fixedly attached to the upper ends of
telescopic tubes 52
which are slidably received in rear leg members 16. The height of push handle
assemblies 50
can be adjusted by extending or retracting telescopic tubes 52 in rear leg
members 16. Telescopic
tubes 52 have a series of through holes at uniform spacing along their length
through which
thumb screws (or other locking pin or bolt) 54 can be selectively inserted to
fix push handle
assemblies 50 at the desired height.
[60.] Push handle assemblies 50 comprise handgrips 60, handle housings 62 and
brake levers
64. Brake levers 64 are operatively connected to brake shoes 66 by length-
adjustable rod
assemblies housed within the telescopic tubes 52 and the rear leg members 16.
Movement of the
brake levers 64 will cause the brake shoes 66 to move into braking engagement
with the tread of
rear wheels 42 thereby arresting rolling motion.
[61.] When walker/transport chair 10 is in the walker configuration as shown
in FIGS. 1 to 3,
the user positions himself behind walker/transport chair 10, and between push
handle assemblies
50 facing the forward direction. In order to function as an effective walker,
it is desirable that
the geometry of the walker be such that the user can position himself far
enough forward that his
center of gravity is vertically aligned over handgrips 60. This will permit
the user to support a
substantial portion of his weight on handgrips 60 when desirable to reduce the
weight on the feet.
[62.] In order to ensure stability of the rollator 10 when a substantial
vertical load is placed on
handgrips 60, the handgrips must be positioned forward of the point of ground
contact of rear
wheels 42. Moreover, in order to facilitate walking, there must be sufficient
room in front of the
user to permit him to extend his feet forward in a natural walking gait
without interfering with
the rollator structure, and in particular with the seating surface.
Accordingly, the position of
seating surface 34 is biased to the front of walker/transport chair 10 such
that its rear edge 71 is
forward of handgrips 60. In addition, seating surface 34 can be flipped to a
vertical position
about transverse seat support member 20 as described above. This will provide
the user with
additional space to move forward between push handle assemblies 50 if desired.
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163.1 When the user wishes to rest, he simply turns around between push handle
assemblies 50,
using handgrips 60 for support if required, and sits down on seating surface
34, with his feet on
the ground. Backrest 70 is provided to support the user's back while seated on
walker/transport
by chair 10. Backrest 70 is attached to extension arms 72 which are fixed at
their rearward ends
to push handle assemblies 50.
[64.] FIGS. 6, 7 and 8 show the details of extension arms 72 and the manner in
which backrest
70 is attached to extension arms 72. The extension arms 72 each have an inward
facing part-
annular recess 96 with a central cylindrical bore 98 formed therethrough. The
backrest 70 has
formed therein two mounting points 100 and 102 for attachment to extension arm
72. Mounting
point 100 can be used as the point of attachment for a larger user whereas
mounting point 102
effectively shortens the length of backrest 72 for a smaller user. The
configuration of mounting
points 100 and 102 is identical and will be described with reference to point
102, which is visible
in FIG. 8.
[65.] The backrest 70 is formed of a flexible plastic material and at each end
has a connection
piece 80. The backrest 70 and the connection piece 80 can be unitarily molded
of a suitable
plastic material that has sufficient flexibility in the central back-
supporting area to conform to
and support a user's back and sufficient mechanical strength to function as a
connection piece. In
the alternative, the backrest 70 and the connection piece 80 can be separate
components joined
together. Moreover, the backrest 70 can be formed of a rigid material such as
aluminum if a non-
flexible back strap type backrest is desired. The connection piece 80 has an
outwardly projecting
key type lug 82 and a central bore 84 formed therethrough. Part-annular recess
96 in extension
arm 72 is sized to fit over and closely receive key type lug 82 on backrest 70
with the cylindrical
bores 84 and 98 axially aligned. A suitable bolt (not shown) with a smooth
shank passes through
cylindrical bores 84 and 98 and is fastened with a captive nut (not shown)
located in hex-head
recess 86 in connection piece 80. In this manner, backrest 70 is pivotally
connected to extension
arms 72.
[66.] Stop lug 104 projects inwardly of recess 96 in extension arm 72.
Abutment surface 106
on stop lug 104 limits forward rotation of backrest 70 by contacting key type
lug 82 in
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Patent
connection piece 80 and maintains backrest 70 in the forward facing horizontal
position.
Similarly, abutment surface 108 limits rotation of backrest 70 by contacting
key type lug 82 in
connection piece 80 and maintains backrest 70 in the rearward facing
horizontal position. This
arrangement permits backrest 70 to be manually flipped from the forwardly
extending position
shown in FIGS. 1 to 3 for use in the walker mode, to the rearwardly facing
position, shown in
FIGS. 4 and 5 for use in the transport chair mode.
[67.] When walker/transport chair 10 is in the transport chair configuration,
the user or a care-
giver flips backrest 70 to the rearward extending position as shown in FIGS. 4
and 5. The user
positions himself in front of and facing away from walker/transport chair 10
and sits down on
seating surface 34 with his back against backrest 70. Footrest 72 is then
folded from the stowed
position shown in FIGS. 2 and 3 to the deployed position shown in FIGS. 4 and
5. In this
position, i.e. the transport chair mode, the user rests his heels on footrest
tray 76, and can be
comfortably propelled by the caregiver. (Footrest 72 has been omitted from
FIG. 1 to show
greater detail of crossbar 68). The forward facing seated position is not only
useful when the
apparatus is being propelled by a caregiver in the transport chair mode, but
also permits the
apparatus to be positioned close to a table, for example when eating a meal.
Conventional
walkers in which the user is seated in the rearward facing position are not
well suited to this
application because the rearward projecting handgrips and the rear wheels
limit how close the
walker can be placed, while the seating surface is typically positioned far
forward of the
handgrips.
[68.] Conventional walkers usually require a crossbar between the front leg
members to
strengthen the frame against collapse when the walker is bearing substantial
weight, for example,
when the user is seated. A front crossbar is particularly required where the
front leg members
are pivotally attached to the frame to permit folding, which pivotal
attachment provides little
resistance to outward splaying of the legs under load.
1694 For conventional walkers, the presence of a crossbar between the front
legs of the walker
typically does not interfere with the user's movements, as the user is
positioned behind the
walker in both the walking and sitting positions. However, the front crossbar
on a conventional
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walker interferes with its use as a transport chair. In particular, in order
to assume the forward
facing sitting position in the transport chair mode, a user must be able to
position his heels very
close to a point on the ground directly under the front edge of the seating
surface. If the user is
positioned too far forwards, he tends to lose balance when attempting to
assume the seated
position, falling backward in an uncontrolled manner onto the seating surface.
This can cause the
walker to upset resulting in serious injury to the user. Conventional cross-
bars are usually
positioned well forward of the front edge of the seating surface and
accordingly tend to prevent a
user from positioning his heels close to a point on the ground directly under
the front edge of
seating surface.
[704 The walker/transport chair design of the present invention is configured
to overcome the
limitations of conventional walker frame design. First, as seen in FIG. 1
front leg members 12
are positioned at an angle closer to vertical than are most conventional
walkers. This minimizes
the extent to which the lower ends of front leg members 12, and consequently
crossbar 68,
project forward of the forward edge 90 of seating surface 34. However, this
has the undesirable
effect of shortening the wheelbase and lessening stability. In order to
provide for a lengthened
wheelbase, the front fork assemblies 48 are not secured axially inside the
lower end of front legs
12, as is conventional practice in walker design. Instead, front fork
assemblies 48 are secured in
end fittings 40, which project forwardly from the lower end of leg members 12,
effectively
lengthening the wheelbase.
171.1 Another feature of the present invention that enhances its use as a
transport chair is the
design of crossbar 68. As best shown in FIGS. 4 and 5, cross-bar 68 attaches
to front leg
members 12 at their lower ends, which point is forward of the forward edge 90
of seating surface
34. In order to permit the user to more safely assume the forward-facing
seated transport chair
position, cross-bar 68 is rearwardly curved such that its central portion is
located substantially
under the forward edge 90 of seating surface 34. This curved cross-bar
arrangement permits the
user to place his heels close to a point on the ground directly under the
front edge of seating
surface, and thereby. While a curved geometry is shown in the drawings, other
configurations
could be used so long as the crossbar is configured such that its central
portion is located
substantially under or behind the forward edge 90 of seating surface 34.
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[72.1 Construction details of crossbar 68 and end fittings 40 can be seen in
FIGS. 9 to 11.
Crossbar 68 and end fittings 40 are unitarily molded or cast from a material
of suitable strength.
For example crossbar 68 can advantageously be formed of cast aluminum.
Cylindrical bores 120
are provided in crossbar 68 to receive connector piece 122, which is bolted
into the lower ends of
forward leg member 12. Front fork shaft 124 is vertically received in bore 126
and is rotatably
retained by upper and lower bearings 128 fitted in bore 126.
j73.] As noted above, the front fork assemblies of conventional walkers are
typically inserted
directly into the hollow ends of the leg members. The fork-mounting shaft is
usually carried in a
single bearing, which is press-fitted into the bottom end of the leg member.
This arrangement is
prone to failure. In particular, repetitive striking of the wheels into curbs
and other obstacles and
impact over rough road surfaces has a tendency to deform and widen the lower
end of the leg
members into which the bearing is pressed. This can cause the bearing, and the
entire fork/wheel
assembly to fall out of the bottom of the leg member. By mounting the front
fork assemblies 48
to end fittings 40 fitted with two bearings, rather than directly into a
single bearing in the bottom
end of the leg, the ability of the fork assemblies and the lower leg mounting
hardware to absorb
shock, without failure is greatly improved.
[74.] The design of the walker/transport chair 10 permits the use of a novel
and effective
braking system. Conventional walkers use Bowden cables, which extend from the
handgrip
mounted brake levers to the braking wheels. Bowden cables are relatively
inexpensive and
because they are flexible, can be installed with excess length in a
freestanding loop or bight to
accommodate changes in length occasioned by the adjustment of handgrip height.
However, the
use of a Bowden cable arrangement has a number of disadvantages. The same
freestanding loop
or bight that permits handgrip height adjustability is prone to being caught
or hooked on various
obstructions, particularly when the walker is loaded into, or unloaded from
the trunk of a car. In
addition, Bowden cables must be accurately adjusted and even a slight lack of
adjustment can
cause unsatisfactory braking action.
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[75.] The design of the present invention permits the use of an internal brake
actuating
mechanism. Referring to FIGS. 12 and 13, a handle housing 62 comprises right
side housing
shell 200 and left side housing shell 202, which are bolted at their lower
ends to telescopic tube
52. The handgrip 60 is bolted between right side housing shell 200 and left
side housing shell
202 at their upper ends. The brake lever 64 is retained between right side
housing shell 200 and
left side housing shell 202 in the manner described below.
[76.1 Referring to FIG. 12, the inside face of right side housing shell 200 is
shown. Raised
wall 204 forms an elongated groove 206 on the inside face with a longitudinal
axis that is
parallel to telescopic tube 52. Semicircular bearing surfaces 208 are formed
in the lower portion
of the inside face.
[77.] Referring to FIGS. 14 to 16, brake actuator 210 has raised tongue
portion 212, which is
sized to be slidably retained in elongated groove 206 of right side housing
shell 200, and
cylindrical portion 214, which is sized to be slidably retained in
semicircular bearing surfaces
208 of right side housing shell 200.
[78.] FIG. 17 shows the position of brake actuator 210 when it is slidably
received in right side
housing shell 200. Bias spring 218 is carried between retaining lug 216 formed
at the upper end
of brake actuator 210 and stop wall 220 formed at the upper end of groove 206
and biases brake
actuator 210 in the downward direction. Brake actuator 210 has elongated
aperture 215 formed
through cylindrical portion 214. This elongated aperture 215 permits
cylindrical portion 214 to
extend down into telescopic tube 52 and allow bolts to pass through bolt holes
217 in right side
housing shell 200, telescopic tube 52, elongated aperture 215, telescopic tube
52 and bolt holes
217 in left side housing shell without interfering with the vertical sliding
motion of brake
actuator 210. Such a through-bolting arrangement greatly improves the
mechanical strength of
the attachment of push handle assemblies 50 to telescopic tubes 52.
[79.] Referring to FIGS. 18 and 19, brake lever 64 comprises upper arm 220 and
lower arm
222 joined at their rear extremities by ball shaped gripping projection 224.
Brake lever 64 is
shaped such that braking action, as more completely described below, can be
effected by placing
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the hands on handle grips 50, inserting fingers through opening 226 and
pulling up on upper arm
220 with inward gripping action. Downward pressure on lower arm 222 will move
brake lever 64
downward into a locked or "parked" position, also as more completely described
below. Ball
shaped gripping projection 224 assists in moving brake lever in a downward
direction by
enabling the user to hook a thumb over the projection to apply downward force.
This is
particularly useful for a user with strength or mobility limitations in the
hands.
[80.] Pivot pin 228 projects from the left side of brake lever 64 at its
forward end and is sized
to be received in slot 230 (Figure 13) formed in the inside surface of left
side housing shell 202.
Brake actuating lug 232 projects from the right side of brake lever 64 and its
upper surface
engages downward facing abutment surface 234 formed in brake actuator 210.
Camming lug 236
projects from the left side of brake lever 64. A brake-lock actuating lug 238
projects from the
right side of brake lever 64 at its forward end opposite pivot pin 228.
[81.] Referring to FIGS. 20 and 22, brake lever 64 is shown in the neutral
position when no
manual braking action is applied. In this position, the brake lever 64
projects rearwardly in a
direction slightly below horizontal. Pivot pin 228 rests at the bottom of slot
230 in left side
housing shell 202 and camming lug 236 (shown in phantom lines) rests on upward
facing
abutment surface 240 formed on the inside surface of left side housing shell
202. Brake lever 64
is retained in this position by the downward pressure of bias spring 218
acting on brake actuator
210, as can be seen with reference to FIG. 17.
[82.] Downward facing abutment surface 242 (shown in phantom lines) formed in
brake
actuator 210 abuts the upper surface of the brake-lock actuating lug 238
(shown in phantom
lines) formed in brake lever 64 and the downward action of bias spring 218 on
brake actuator
210 urges pivot pin 228 to the bottom of slot 230. Similarly, downward facing
abutment surface
234 (shown in phantom lines) formed in brake actuator 210 abuts the upper
surface of brake
actuating lug 232 (shown in phantom lines) formed in brake lever 64 and the
downward action of
bias spring 218 on brake actuator 210 urges camming lug 236 into engagement
with upward
facing abutment surface 240.
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[83.] Thus in the neutral position as shown in FIGS. 20 and 22, brake lever 64
rests with pivot
pin 228 at the bottom of slot 230 and camming lug 236 resting on upward facing
abutment
surface 240. Brake actuator 210 is urged downwardly by bias spring 218 and
rests with
downward facing abutment surface 242 resting on brake lock actuating lug 238
and downward
facing abutment surface 234 resting on brake actuating lug 232.
[84.1 Referring to FIG. 23, brake lever 64 is shown in the braking position
when manual
braking action is applied. In this position, the brake lever 64 has been
pivoted about pivot pin
228 in the bottom of slot 230 until the upper arm 220 of brake lever 64 is
substantially
horizontal. This pivoting action causes brake-actuating lug 232 (shown in
phantom lines) to raise
brake actuator 210 by engagement with downward facing abutment surface 234
(shown in
phantom lines). By manually releasing brake lever 64, bias spring 218 will
urge brake actuator
210 back to the neutral position shown in FIG. 13. The upward motion of brake
actuator 210
between the neutral and braking positions is transmitted to rear wheel brake
shoes 66 in a manner
described below.
[85.1 Referring to FIGS. 21 and 24, brake lever 64 is shown in the locked or
"park" position.
In this position, brake lever 64 has been pivoted down about camming lug 236
(shown in FIG. 21
in phantom lines). This pivoting motion causes pivot pin 228 to move upward in
slot 230 and
draws camming lug 236 forward over upward facing abutment surface 240 onto
lower abutment
surface 246.
[86.] As can be seen with reference to FIG. 24, this pivoting motion causes
brake lock
actuating lug 238 (shown in phantom lines) to raise brake actuator 210 by
engagement with
downward facing abutment surface 242 (shown in phantom lines). Brake lever 64
is retained in
this locked or "park" position by the downward pressure of bias spring 218
acting on brake
actuator 210 which urges camming lug 236 backwards into engagement with
forward facing
abutment surface 248. Downward bias is also provided by spring 290 (see FIG.
27). By applying
manual pressure to raise brake lever 64, camming lug 236 is raised over
forward facing abutment
surface 248 and returns to the neutral position shown in FIG. 22. Thus, the
sliding movement of
camming lug 236 over forward facing abutment surface 248 provides an over-
center action to
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lock and unlock brake lever 64. The upward motion of brake actuator 210
between the neutral
and lock or "park" positions is transmitted to rear wheel brake shoes 66, as
described below.
[87.] As is evident from the foregoing description, the user can apply and
release a braking
force to the rollator by pulling up and releasing brake lever 64, and can
apply a constant braking
force by pushing brake lever 64 down into the locked or "park" position.
[88.] Referring now to FIG. 25, the manner in which the upward motion of brake
actuator 210
is transmitted to rear wheel brake shoe 66 is shown. Brake actuator 210 is
bolted in the upper
end of telescopic tube 52 as described above. Telescopic tube 52 is slidably
received inside rear
leg member 16. Rear leg member 16 is fixedly attached to fixed rear leg
bracket 26 in a manner
that leaves the inside volume of rear leg member 16 open to permit telescopic
tube 52 to slide
therein. For example, bosses having threaded sockets can be provided on the
outer surface of rear
leg member 16 and corresponding keyway can be formed in fixed rear leg bracket
26 to receive
such bosses. Leg 16 and bracket 26 can then be secured by bolting through an
aperture in the
keyway into the threaded sockets.
[89.] Telescopic tube 52 is provided with a series of evenly spaced holes 254
along a portion of
its length. Fixed rear leg bracket 26 has a transverse bore 256 formed in each
side, with the inner
bore being internally threaded to receive the threaded end of thumb screw 54
(see FIG. 1).
Handgrip assembly 50 may be fixed at the desired height by aligning a selected
hole 254 in
telescopic tube 52 with bore 256 in bracket 26. Thumb screw 54 is inserted
into the outer bore
256 of bracket 26, through the selected hole 254 in telescopic tube 52, and is
screwed into the
threaded inner bore 256 on the opposite side of bracket 26.
[90.] This arrangement provides for a secure manner of adjustably attaching
handgrip
assembly 50 to the fixed rear leg bracket 26 of the walker. The use of
thumbscrew 54, which
passes entirely through telescopic tube 52 and is threaded into the opposite
side of bracket 26,
distributes the load applied by the user on handgrip assemblies 50 evenly
across bracket 26. This
is a far more durable means of attachment than that one which merely secures
the telescopic tube
by a thumbscrew, which passes through one wall of the bracket and squeezes
against the outer
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surface of the telescopic tube. A solid attachment between the telescopic tube
52 and bracket 26
is extremely important not only for reasons of durability and safety, but also
because of the sense
of security imparted to the user. Users are fax less willing to accept a
walker if the handgrip
assemblies feel loose or flimsily mounted. While the through-bolt arrangement
of thumbscrew
54 does offer enhanced durability, it does require a special arrangement to
permit brake actuation
internally within telescopic tube 52.
[91.] Referring to FIG. 25, a brake wire 250 is formed in an inverted "U"
shape with a bight at
an upper end thereof being retained in groove 252 formed in the cylindrical
portion 214 of
actuator 210. Downwardly extending legs 258 and 260 of the brake wire 250,
which form a gap
therebetween, are attached to the brake rod 262 by means of a clamp 264. The
brake rod 262 is
an elongated "U" shaped channel member.
[92.] Referring to FIG. 26, clamp 264 has back surface 268 and side surfaces
270, which are
sized to be closely received in the "U" channel of brake rod 262. Recesses 272
are provided to
accommodate downwardly extending legs 258 and 260 of brake wire 250, and teeth
274 are
formed in recesses 272 to grip brake wire 250. The clamp 264 is drawn tight
against the upper
end of the brake rod 262 by means of an Allen screw 266, whereby the teeth 274
trap and secure
the brake wire 250 against the brake rod 262. The Allen screw 266 is axially
aligned with the
first hole 254 in the telescopic tube 52 above bracket 26 permitting a wrench
or key to be
inserted therethrough for the purpose of loosening or tightening clamp 264.
The brake wire 250
can advantageously be formed of wound steel piano wire, e.g. 0.09 inch
diameter, as the ridged
surface thereof can be securely gripped by the teeth 274.
[93.] Elongated slot 276 is formed in the center web of brake rod 262.
Thumbscrew 54, which
is threaded into transverse bore 256, passes through slot 276. Slot 276 is
sized as to permit brake
rod 262 to be displaced longitudinally by the upward and downward movement of
brake actuator
210 without contacting thumbscrew 54.
[94.] In order to adjust the height of handgrip assemblies 50, a key or wrench
is inserted
through hole 254 above bracket 26 and Allen screw 266 is loosened to permit
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longitudinal movement between the brake wire 250 and the brake rod 262. The
thumbscrew 54
is then unscrewed and withdrawn from the transverse bore 256. The telescopic
tube 52 is then
raised or lowered until the desired hole 254 is axially aligned with the
transverse bore 256 and
the thumbscrew 54 is reinserted and tightened to secure telescopic tube 52 in
bracket 26. Finally,
Allen screw 266 is tightened to secure the brake wire 250 to the brake rod
262.
[95.] Referring to FIG. 27, rear fork assembly 44 comprises inner and outer
fork housings 280
(only one of which is shown in FIG. 20) between which the rear wheel 42 is
mounted for rotation
about the axle 282. Rear fork assembly 44 is attached to rear leg member 16 by
means of
through-bolts (not shown), which pass through holes 283 in the fork housings
and rear leg
member 16. Brake shoe 66 is pivotally mounted on shaft 284, which is
transversely secured
between fork housings 280. Brake rod 262 is connected at its bottom end to the
brake shoe 66 at
pivot point 286. Elongated slot 288 is provided in the centre web of brake rod
262 to permit the
through-bolts to pass therethrough and is sized to permit brake rod 262 to be
displaced
longitudinally by the upward and downward movement of brake actuator 210
without contacting
the through-bolts. Spring 290 is retained between lug 292 and housing 280 and
biases brake shoe
out of engagement with rear wheel 42.
[96.] Referring to FIGS. 28 to 30, the details of brake shoe 66 can be more
readily seen. Brake
shoe 66 has a horizontally disposed upper surface 294 and vertical sidewalls
296, which together
bound a downwardly open cavity. Friction member 294 is carried within said
cavity and is
attached thereto at point 300. Friction member 294 has downwardly protruding
tang 302 at its
rearward end. Adjusting screw 304 is threaded through the upper surface 294 of
brake shoe 66
and contacts the upper surface of friction member 294. The extent to which
tang 302 protrudes
below brake shoe 66 can be varied by turning adjusting screw 304 in or out.
This adjustability
permits fine-tuning of the braking action and compensates for tire wear.
[97.] When brake rod 262 is moved upwardly by the operation of brake lever 64,
brake shoe 66
is caused to pivot about shaft 284 forcing tang 302 downward into frictional
engagement with
rear wheel 42. When brake lever 64 is released and returns to its neutral
position, brake rod 262
moves downwardly and brake shoe 66 pivots out of frictional engagement with
rear wheel 42. In
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this manner, braking action is transmitted from the brake lever 64 to the
brake shoe 66 internally
of telescopic tube 52 and rear leg member 16.
[98.] An alternative embodiment for a height adjustable brake according to the
present
invention is illustrated in Figures 31 to 36, and includes an upper brake leg
410 slideably
receiving a lower brake rod 411. The cylindrical portion 214 of brake actuator
210 is fixed to an
upper end of the upper brake leg 410 by fastener 412. The lower end of the
upper brake leg 410
receives the upper end of the lower brake rod 411. A lock button 413 is spring
biased outwardly
through a hole 414 in the upper end of the lower brake rod 411 by a spring 416
for adjustably
connecting the lower brake rod 411 to the upper brake leg 410. An elongated
groove 418
extends through the wall of the upper brake leg from the lower end to the
upper end thereof for
slideably receiving the lock button 413. Channels 419 extend perpendicularly
from the groove
418 providing several resting places for the lock button 413 defining a
plurality of positions
corresponding to different predetermined heights of the handgrip assemblies
50. The lower end
of the lower brake rod 411 is connected to the rear fork assemblies 44 by a
bolt 420, which
extends through an opening 421. A spacer bushing 423 surrounds the bolt 420
providing a
smooth bearing surface enabling the lower brake rod 411 to rotate slightly
about a longitudinal
axis thereof during height adjustment. The opening 421 has a diameter slightly
larger than an
outer diameter of the spacer bushing 423 to facilitate relative rotation. The
slight twisting of the
lower brake rod 411 enables the lock button 413 to disengage from one of the
channels 419
during adjustment. A coil spring 424, surrounding the spacer bushing 423,
spring biases the
lower brake rod 411 to the normal use position, i.e. biases the lock button
413 back into one of
the channels 419.
[99.] During height adjustment, as the lock button 413 engages one of the
channels 419,
elongated slots 426 in opposite sides of the lower brake rod 411, forming gaps
therein, become
aligned with one of a series of elongated apertures 427 in the upper brake leg
410 for receiving
the thumb screw 52 or some other locking bolt, rod or pin. Accordingly, the
thumbscrew 52
extends all the way through the fixed rear leg bracket 26, the telescopic tube
52, the lower brake
rod 411 and the upper brake leg 410 providing a secure locking feature between
the fixed rear
leg bracket 26 and the telescopic tube 52, while providing reciprocal movement
of the lower
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Patent
brake rod 411 and the upper brake leg 410, enabling actuation the brake levers
64. Moreover,
the thumbscrew 52 ensures that the upper brake leg 410 does not rotate
relative to the lower
brake rod 411, thereby disengaging the lock button 414 from the selected
channel 419.
[100.] While the present invention has been described with reference to the
embodiments
disclosed in the Figures, it will be understood that variations and
modifications may be made
without necessarily departing from the scope of the invention. Accordingly,
the scope of the
invention is to be determined in accordance with the claims appended hereto.
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