[0001] The present invention relates to wheeled walking aids, in particular to mechanically
engineered appliances for assisting persons with impaired function of lower extremities
who are unable to walk with the use of prior art walking aids because they lose their
delicate balance when obliged to lift and/or push the frame partially or totally off
the supporting surface. It is the main aim of the present invention to provide a low
cost walking aid that offers a better technique for advancement and obviates the requirement
to lift and/or push the frame.
[0002] The present invention unlike the prior art walking aids is engineered to advance
in sync with user, step-by-step without the user ever having to lift the frame totally
or partially off the supporting surface to advance, the frame is mechanically engineered
to progress on all four mono-directional ratchet wheels, by simulating a gait cycle
known as the "two-anchor movement" which works on the same principle that the inchworm
uses, whereby on either end of the body/frame, the clasping appendages/ratchet wheels,
allow it to move by anchoring first the rear end and then moving forward the front
end, then anchoring the front end and moving forward the rear end in predetermined
lengths.
[0003] Many forms of support for walking have been provided, of greater or lesser complexity,
to accommodate differing degrees of severity of injury/illness. Typically, standard
walking aids are supported on four fixed standing legs, pulpit-like frames constructed
of aluminum tubing, permitting relatively dysfunctional users, while holding the upper
portion of the frame, to stand, steady themselves and attempt to advance. To achieve
a fluent walking pattern with one of these prior art frames is not an easy task because
body alignment, trunk positioning, weight distribution, balance, stability and control
are all compromised when walking needs to be effected by the user, intermittently
lifting the frame off the ground, repositioning it ahead, then stepping forward. In
the anxious days following an accident or stroke, many patients have difficulty in
lifting and sliding a frame forward due to a multitude of factors, compounded by a
state of fear, shock and lack of focus, coordination, balance and confidence.
[0004] There have been attempts to introduce other forms of walking aid to overcome the
need for having to lift the frame totally off the supporting surface, the most relevant
being United States Patent No.
2,656,874 from W.C. Robb, 1953, but this and other similar inventions have not been successful due to the instability
of their method of advancement.
[0005] A serious additional problem with most prior art walking aids is that they promote
stooping, which can exacerbate the user's condition. To this end, two-wheeled pulpit
frames have been provided by prior art with wheels on the front legs, replacing the
ferrules, but these are not a great improvement on the standard fixed pulpit frames.
[0006] It is hoped that by using simple step rehabilitation devices like the present invention
some of these problems can be circumvented. Designing better and cheaper equipment
for the home that can, for example, reduces the number of therapists needed for supervision.
In the continuum of care, efforts in the direction of increasing medical equipment
and services for the home can be the most cost-effective.
[0007] According to the invention a walking aid comprising in combination a front member
and a rear member, each having a pair of mono-directional ratchet type wheels at its
lower ends, hinge means with adjustable degree of rotational freedom pivotally connecting
the said front and rear members together at their upper ends, adjustable spring means
around the pivots connecting the said hinges providing resistance when front member
extends forward and assistance when rear member retracts forward, a rearward extending
u-shaped handlebar with handgrips attached to the rear member for support, between
which user stands squarely within the wheel base. Pushing down on the said handgrips
forces the rear ratchet wheels to anchor on the supporting surface allowing the front
wheels to advance spreading the supporting trestle-like structure, pulling up on the
handgrips forces the front ratchet wheels to anchor and allow the rear wheels to retract
to original position.
[0008] It is also the aim of this invention to provide a walking aid designed to place the
user's centre of mass at the optimal functional position, squarely within the wheel
base to help encourage an upright body posture, a 'neutral spine' trunk stability
and support throughout the process to give greater confidence to patients who can't
stoop over without loosing their balance.
[0009] It is also the aim of this invention to provide a walking aid that can be converted
to accommodate patients with varying degrees of instability and differing surfaces.
For example the standard mono directional, ratchet type rear wheels as shown in fig.
6 that incorporate a safety brake mechanism to engage when the slightest additional
or sudden unintended pressure or load is applied in the forward direction. Another
option is the mono-directional ratchet type wheel with a pin mechanism that when disengaged
allows the user forward and reverse mobility. Another option is a mono-directional
front swivel type wheel with locking mechanism that can switch from swivel to non-swivel
still retaining the anti roll-back feature.
[0010] It is also the aim of this invention to provide a walking aid that can be used as
painlessly as possible by offering anatomically contoured hand grips, a natural wrist
angle to spread weight over a wider area of the palm helping reduce the pressure on
the carpal tunnel and improve blood circulation especially when transferring some
or all of the weight through the forearms to the frame previously carried through
the legs, giving the lower limb joints the necessary support thus minimizing pressure
over weight bearing joints as well as impact on the lower spine, hip, knee, ankle
and foot.
[0011] It is also the aim of this invention to supply a walking aid with adjustable forearm
cuffs like elbow crutches that can be extended between the handgrip and cuff of forearm,
further ensuring correct positioning of the body within the frame as well as enhancing
stability, control, balance and comfort.
[0012] It is also the aim of this invention to provide a walking aid that is easily adjustable
in width and height to fit any size to help the unique user achieve the perfect supporting
stance within the frame with elbows naturally bent, at an angle of approximately 15
degrees flexion and wrist bones in line with the handgrips.
[0013] It is also the aim of this invention to provide a walking aid with an adjustable
spring or hydraulic damping means to urge the front and rear members to alternately
spread and retract relative to each other to the desired requirement of the user.
[0014] In order that the invention may be more clearly understood, one form of walking aid
made in accordance with the invention is described with reference to the accompanied
drawing wherein. Although the present preferred form of this invention has been herein
shown and described, it is to be understood that such has been done for purposes of
illustration only, and that various changes may be made therein within the scope of
the appended claims.
Figure 1, shows a side view of the apparatus locked in the minimum aperture as well
as shadows of the same apparatus locked in the maximum and minimum apertures.
Figure 2, shows an end view the apparatus from the rear.
Figure 3, shows a top view cross section of the connecting link, torsion spring.
Figure 4, shows a side view of the connecting link, torsion spring, damper and hinge
mechanism in the minimum aperture position.
Figure 5, shows a side view of the connecting link, torsion spring, damper and hinge
mechanism in the maximum aperture position.
Figure 6, shows details of an alternative attachment with Sure Grip safety breaking mechanism.
[0015] The walking aid comprises a back member
2a with a mounted u-shaped bar
2c, forming the back end which is pivotally linked with a torsion spring system at
3 near the top ends of each of the back legs
2a&2b attaching to the front legs
1a&1b which are interconnected by cross bars
1c&1d to form a front member that is pivotally attached to the back member as in a trestle-like
structure. At the feet of both the front and back legs
1a, 1b&2a,2b are mounted mono-directional ratchet type wheels 4 to prevent backward slip at all
times when in use.
[0016] The front and rear legs of the said trestle like structure are joined near the top
3 by a pivotally attached torsion sprung link and damper system as shown in
figures 3,4&5. On either side, comprising rear links
2e, 2d and front links
1e, 1f pivotally attached to the rear and front legs respectively and pivotally attached
to each other by a pivot
7. The back link is formed with slots relative to the pivots
2d (ii) in which move pin members
9 attached to the front links
1e, 1f. Between the over-lapping ends of the links are positioned springs
6 which tend to draw the legs towards one another.
[0017] As seen from
Figure 1 and
Figure 2 each pair of front and rear links forms a stay which not only limits the opening
or separation of the front and rear members but also limits their closed position
so that in either position they provide a stable trestle-like structure from which
the user can obtain support in all directions.
[0018] On the top of the back member
2a, 2b is mounted an inverted U-shaped top bar
2c for the handles. The handles are completed by rubber grips
5 that project rearward to permit the user to stand between the handles and obtain
support there from.
[0019] As seen from
Fig. 3, 4 and 5 the spring
6 shown in Figure 3 is coiled around the pivot
7&8 and has its ends bent outwardly and located in holes in the links
2d(i) and
1f(i) respectively.
Amended claims in accordance with Rule 137(2) EPC.
1. What I claim is a mechanically engineered walking and gait training device to help
train and assist persons with impaired function of lower extremities to walk, said
device comprising a combination of two parts, a front member and a rear member, linked
together by sprung hinge means, loading said front and rear members angularly toward
each other, offering resistance against gravity when front member extends forward,
and assistance when rear member retracts forward, means positively limiting the range
of motion of said front and rear members towards and away from each other, handlebar
with handgrips attached to the front or rear member, together forming a trestle-like
structure characterised by four mono-directional, one-way, ratchet type supporting wheels at its lower ends,
safety brake mechanism integrated on the rear wheels, a mode of operation that simulates
the gait cycle known as 'two-anchor movement', without having to be lifted off the
supporting surface.