Note: Descriptions are shown in the official language in which they were submitted.
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DEVI OE FOR LOADING A PERSON INTO A WHEELCHAIR
This invention relates to apparatus for loading persons into
wheelchairs.
US patent No. 3,694,829 discloses a patient lifting
apparatus suitable for transferring a patient into a wheelchair.
The apparatus comprises a mobile carriage with a vertical column
having arms extending from its upper end. A sling arrangement,
which is connected to the outer end of the arm for supporting the
patient, comprises in part a back belt and a sling belt extending
at an angle to each other. A patient is held by the pair of
belts such that his back and upper part of his legs extend
generally normal to each other. The patient carried in the sling
may be lowered into a wheelchair. Unfortunately, when the sling
is in a raised position, the back of t~le patient is caused to
recline at an angle between approximately 10 and 20 to the
vertical. While occupational therapists may sometimes specify
otherwise in special cases, as a general rule the back of a wheel
chair is vertical. As a result, when the patient is lowered into
the wheelchair, the upper part of the patient's back is supported
by the back of the wheelchair but the lower part of the patient's
back is some distance away from the back of the wheelchair.
Understandably the patient is not correctly supported in such a
position. To pull the patient backwards when seated could cause
injury to both patient and attendant, and is not allowed in some
hospitals. To move the patient into a more rearward and more
supported position, attendants must pull the patient backwards
during lowering of the patient to place him as rearwardly as
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possible upon the wheel chair seat. This tends to be a difficult
operation and in most cases requires at least two attendants.
If only one attendant were to stand behind the wheelchair while
attempting to pull the lower part of the patient's body towards
him, the strain involved could cause injury to the attendant.
This is even more likely if the wheelchair is motorized and has
drive equipment, such as batteries, mounted at the rear of the
wheelchair.
The present invention seeks to provide apparatus for use in
loading a patient into a wheelchair which minimizes the above
disadvantages.
Accordingly, one aspect of the present invention provides
apparatus for loading a person into a wheelchair comprising
person lifting means for supporting a person in a backwardly
inclined seated posture above a wheelchair loading position; and
means for causing a wheelchair located in the loading position
to tilt backwards into a tilted position suitable for lowering
the person carried by the lifting means into a desired seating
posikion in the wheelchair.
This aspect of the present invention thus uses a lifting
means for a person together with a means for causing a wheelchair
to tilt backwards ready for receiving the patient. When the
wheelchair is tilted backwards into its tilted position, the
wheelchair back may be inclined at an angle approximately e~ual
to the angle of inclination of the back of the person supported
by the lifting means. Hence the person may be lowered directly
into a desirable seating position in the wheelchair with his back
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substantially completely supported by the wheelchair back. The
need for manual intervention for the purpose of correctly
positioning the patient is thereby avoided, together with its
attendant problems.
The means for causing tilting of the wheelchair preferably
comprises a ramp structure. Such a structure may be a separate
unit easily accommodated, dependent upon its design, beneath the
lifting means in the wheelchair loading position. The ramp
structure may have inclined surfaces and wheel support surfaces
extending from upper ends of the inclined surfaces to enable
front wheels of the wheelchair to move up the inclined surfaces
into an elevated position on the support surfaces to provide the
tilting action.
Preferably, fixed stop means are provided to prevent
movement of the wheels off the furthestmost end of the wheelchair
support surfaces. Means may also be provided for releasably
retaining the front wheels in the elevated position to resist
movement of the front wheels in one direction onto and down the
inclined surfaces.
The means for releasably retaining the front wheels in the
elevated position may comprise at least one removable stop
element disposable in the position for location behind the front
wheels of the wheelchair when these are in the elevated position
so as to prevent movement of the front wheels down the inclined
surface means.
It is also preferable for the ramp structure to comprise two
ramp members each providing an inclined surface of the inclined
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surface means. I~ this case the means for retaining the front
wheels in the elevated position comprises a wheelchair support
surface provided by each ramp member. It is also preferable for
each of the inclined wheelchair support surfaces to be provided
by a guide channel for accepting and guiding the front wheel of
the wheelchair.
The ramp members preferably are connected together by
connector means which are adjustable to enable the separation
between the ramp members to be adjusted to different fixed
spacings to suit different wheel spacings. For this purpose, the
connector means may comprise pairs of connector members with the
members of each pair being connected one to each ramp member and
being relatively movable lengthwise one on another. With this
arrangement means is provided to sscure the connector members in
different relative positions. Each pair of connector members may
comprise a pair of telescoping tubes, in which case a plurality
of location holes may be provided in the tube to enable alignment
of different holes from tube to tube upon change of fixed
position of the inclined surfaces. The means for securing the
tubes in different relative positions could, in this case,
comprise a pin for passing into aligned holes of the two tubes.
Alternatively, the ramp structure may be integral with the
lifting means. Such a lifting means may comprise a pair of base
members extending either side of the wheelchair loading position.
The base members may then comprise wheel support surfaces
extending substantially parallel to each other to receive the
front wheels and inclined surface members hinged to the front
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ends of respective wheel support surfaces so that each inclined
surface member would lie upon the wheel support surface when not
in use, and be pivoted into its inclined position for use.
According to a further aspect of the present invention a
ramp structure is provided for use in combination with lifting
means for loading a person into a wheelchair, the ramp structure
comprising a pair of ramps members each having an inclined
surface for movement of a respective front wheel of a wheel chair
up the inclined surface and into an elevated position so as to
tilt the wheelchair, the ramp structure also having means to
removably retain the front wheels in the elevated position with
the wheelchair tilted, and connector means for connecting the
ramp members together with their inclined surfaces at fixed
distances apart.
According to a still further aspect of the present invention
there is provided a wheelchair having jacking means for tilting
the wheelchair backwards, the jacking means being mounted upon
the wheelchair and extensible downwards into engagement with the
floor to elevate the front wheels to a desired height above the
floor.
Another aspect of the invention comprises a method for
loading a person into a wheelchair comprising:- lifting the
person while supporting the person in a backwardly inclined
seated pose; disposing a person above a wheelchair loading
position with a wheelchair located in the wheelchair loading
position and with a chair engagement means in the loading
position causing the wheelchair to tilt backwards into an
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orientation suitable for loading the lifted person into a desired
seating position in the wheelchair; and lowering the person into
the wheelchair and into the desired seating position.
One embodiment of the invention will now be described, by
way of example, with reference to the accompanying drawings in
which:
Figure 1 is a side view of a sling-type patient lifting
apparatus of the prior art, shown with a patient positioned in
the apparatus;
Figure 2 is a side view of the apparatus and patienk of
Figure 1, and further illustrating a wheelchair ready to receive
the patient;
Figure 3 is a side view of apparatus for loading a patient
into a wheelchair according to the embodiment of the invention
and showing a patient lowered into a wheelchair;
Figure 4 is a perspective view of the loading apparatus and
patient of Figure 3;
Figure 5 is a perspective view of a ramp structure forming
part of the loading apparatus of the embodiment;
Figure 6 is a partial plan view of an alternative embodiment
of the invention; and
Figure 7 is a side view of an embodiment of another aspect
of the invention.
With reference to Figure 1, a sling-type lifting apparatus
used to move a disabled person from a bed to a wheelchair, or
vice versa, is generally designated 10. The apparatus comprises
a sling support means which has an undercarriage 12 to which is
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secured a vertical column 14. One end of an arm 16 connects
pivotally to the upper end of column 14, and a hydraulically-
operated piston mechanism 18 connected between column 14 and arm
16 determines the relative angle between those two. A person 20
is carried in a canvas sling 22 which has a set of loops 24 at
each of its corners. Each set comprises several loops (not
shown) to provide for different sizes of patient. The sling 22
is suspended by the loops 24 from the outer end of arm 16.
Handholds 26 are sewn onto the sides and back of sling 22 to
assist with positioning of person 20. The weight of person 20
supported by the sling 22 and the shape of the sling 22 result
in the person 20 adopting a seated pose with the seat 28 of the
person extending at an angle of between approximately 10 and 20
to the horizontal, and the back 30 of the person reclining at a
similar angle to the vertical.
As illustrated in Figure 2, on being lowered into a
wheelchair 40 the person 20 is misaligned with the seat and back
of the wheelchair. This misalignment results in the lowermost
part of the patient's back being anywhere from 1 inch to 6 inches
away from the seat back as indicated at 25. This results because
the seat and back of most wheelchairs extend substantially
horizontally and vertically, respectively. To overcome this
misalignment, it is normally necessary for one or more attendants
to pull on one or more handholds 26 while a further attendant
operates the piston mechanism 18 to lower the patient. If it is
not a high-back wheelchair, an attendant pulling on handholds Z6
may well stand to the rear of, or substantially behind, the
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wheelchair 40, and this may rPsult in considerable strain to the
back of that attendant, especially if the patient is heavy. That
strain may be made worse if the wheelchair is motorized and bulky
equipment, such as batteries, is mounted at the rear of the
wheelchair. A further problem may be that two attendants, one
each side of the wheelchair, pulling on separate handholds 26,
may pull at different rates, and the patient may be misa~igned
to one side or the other when pulled backwards. This could ~ause
the patient to press against the armrest, causing discomfort.
Figures 3 and 4 illustrate apparatus for loading a person
into a wheelchair according to the embodiment of the invention.
This apparatus comprises a sling-type lifting apparatus 10 as
described with reference to Figures 1 and 2 and having a sling
support means and canvas sling 22. The embodiment also includes
a ramp structure 44 for supporting front wheels ~2 of the
wheelchair in an elevated position as shown by Figures 3 and 4.
In this position, the wheelchair 40 is tilted such that its seat
46 and its back 48 extend at an angle to the horizontal and
vertical, respectively. When the wheelchair 40 has its brakes
applied and is secured in this orientation, it is possible, if
regulations permit, for a single attendant to lower a patient in
the sling 22 into the wheelchair 40 such that the patient assumes
a desired final position with his back substantially completely
supported by the wheelchair back. The need for one or more
additional attendants to pull on the handholds 26 during lowering
of the patient is eliminated. In practice, it has been found
that, for many wheelchairs, elevating the front wheels by about
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9 or 10 cms. gives satisfactory results. Typically, less will
not provide sufficient inclination, and more will not be
practical where the wheelchair carries an anti-tipping device,
and/or heavy batteries mounted at the rear.
The ramp structure 44 is more fully illustrated in Figure
5 and comprises a pair of ramp members 50 each having an upper
surface 52 and inclined surface 54. A U-shaped metallic or
plastic section is secured to those surfaces to define an upper
wheel guide channel 56 and an inclined wheel guide channel 58 on
each member 50. Each guide channel 56 provides a wheelchair
support surface to accept a front wheel of the wheelchair after
movement of the front wheel up an inclined surface provided by
the corresponding guide channel 58. One end of each upper wheel
guide channel 56 has a stop means i.e. a pin 60 secured to it to
limit the forward movement of a wheelchair wheel within that
channel. A stop element in the form of a removable or hinged
barrier 62 is mounted at the other end of each upper wheel guide
channel 56. The pair of barriers 62 are not put into position
until the front pair of wheels of wheelchair 40 have moved up
ramped wheel channels 58 and have entered the upper wheel
channels 56. The barriers 62 are then positioned across the
channels 56, behind the front wheels, to prevent the front wheels
from moving onto and down the channels 58.
The members 50 have connector means connecting them
together. The connector means is, in this embodiment, required
to be adjustable to enable the ramp members 50 and thus of their
inclined channels 58 and 56, to be moved towards each other, or
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apart. The connector means comprises two pairs of connector
members, each pair in the form of a pair of telPscoping tubes 64
and 66 with the tube 64 slidable within tube 66.
Each tube 64 has a series of spaced holes 68 along it, and
5 each tube 66 has a hole 70 proximate its outer end. Hole 70 can
be matched to any of the holes 68, and means provided to secure
the tubes in different chosen telescoped positions comprises a
pin 72 inserted to fix their relative position. With the pair
of pins 72 inserted into corresponding holes 68 in tubes 64, the
ramped wheel channels 58 and upper wheel channels 5~ of the pair
of blocks 50 extend respectively parallel to each other. Each
pin 72 is connected by a chain 74 to a ring 76 extending around
a respective tube 66.
An advantage of a separate ramp structure is that the
lifting means 10 can be used without it, for example to lift a
patient onto a stretcher. It will be appreciated, however, that
the ramp structure could be attached to the lifting means and
movable into and out of the loading position as required. Such
an arrangement is illustrated in Figure 6, which shows the base
80 of a person lifting means which is otherwise as shown in
Figure 4. The base 80 comprises a pair of side members 82 and
84 extending from opposite ends of a rear base member 86. A
vertical column 88 extends upwards from the middle of the rear
base member 86. The side members 82 and 84 have respective short
sections 90 and 92 extending parallel to each other and
perpendicularly from the ends of the rear base member 86,
outwardly cranked middle portions 94 and 96, and parallel end
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portions 98 and 100, respectively. The uppermost surfaces of the
sections 90 and 92 carry wheel support channels 102 and 104,
respectively. Incline surface members 106 and 108 are coupled
to frontal ends of the sections so and 92 by hinges 110 and 112,
respectively. In Figure 6, inclined surface member 108 is shown
in the storage position i.e. folded onto the top surface of
section 92. Inclined surface member 106 is shown deployed for
use, i.e. folded out so that it extends downwards and forwards
from the end of wheel support channel 102. As before, fixed
stops 114 are provided at the rear ends of wheel support channels
102 and 104 and releasable stops 118 are provided at their front
ends.
It will be appreciated that the wheel support channels need
not be separate but could be formed into the respective side
member section 90 and 92 during manufacture.
In some kinds of lifting apparatus, the spacing between the
side members 82 and 84 will be adjustable and so may provide for
adjusting the spacing between the ramps to suit different wheel
spacings. Where they are not, however, the wheel support
channels 102 and 104 could be adjustably mounted upon a plate
extending between the sections 90 and 92 so that the spacing
between the ramps could be adjusted to suit different wheel
spacings.
Various alternatives and modifications are possible within
the scope of the invention, as defined by the appended claims.
For example, the ramp structure might comprise a pair of ramps,
each mounted upon one of the side members of the undercarriage
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or base member. Each ramp might be carried by a telescopic
member, perhaps an hydraulic ram, so that it could be withdrawn
to a position adjacent the side member when not in use and
extended inwards from the side member for use. The amount of
extension could be selected to suit different wheel spacings.
It is also envisaged that the lifting means might be
equipped with means other than ramps for tilting the wheelchair.
For example, an hydraulic jack might be provided on the base of
the lifting means to engage the frame of the wheelchair, or a
lever or levers might be employed, attached to either the base
or the vertical column.
Alternatively, the means for tilting the wheelchair could
be a jacking device mounted upon the wheelchair itself and
operable to engage the floor and raise the front wheels to the
desired height. Such a wheelchair is illustrated in Figure 7 and
comprises an hydraulic jack 120 with its cylinder attached to the
underside of the seat so that its piston 122 extends downwards.
The jack 120 is coupled to an operating pedal 124 at the rear of
the wheelchair. When the piston 122 is fully retracted into the
cylinder 120, the front wheels of the wheelchair engage the floor
126 in the normal way. When the pedal 124 is operated, the
piston 122 extends until it engages the floor. Further extension
causes the front wheels to lift from the floor, about 9 or 10
cms., to give the required tilting. The pedal 124 is equipped
with a release valve to retract the piston and lower the front
wheels to the floor after the patient has been lowered into the
wheelchair.
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It will be appreciated that the jacking means need not be
an hydraulic jack. For example, the jacking means might be
levers attached to the frame adjacent the front wheels and
pivotable into engagement with the floor to raise the front
wheels.
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