NZ766300A - A Wheelchair - Google Patents
A WheelchairInfo
- Publication number
- NZ766300A NZ766300A NZNZ766300A NZ76630020A NZ766300A NZ 766300 A NZ766300 A NZ 766300A NZ NZ766300 A NZNZ766300 A NZ NZ766300A NZ 76630020 A NZ76630020 A NZ 76630020A NZ 766300 A NZ766300 A NZ 766300A
- Authority
- NZ
- New Zealand
- Prior art keywords
- frame
- backrest
- wheelchair
- base
- support frame
- Prior art date
Links
- 210000001138 Tears Anatomy 0.000 claims abstract description 10
- 239000000725 suspension Substances 0.000 claims abstract description 10
- 230000037396 body weight Effects 0.000 claims abstract description 7
- 230000000875 corresponding Effects 0.000 claims description 8
- 210000003205 Muscles Anatomy 0.000 claims description 4
- 230000002028 premature Effects 0.000 abstract description 5
- 230000036633 rest Effects 0.000 abstract description 3
- 208000005392 Spasm Diseases 0.000 abstract description 2
- 230000011514 reflex Effects 0.000 abstract description 2
- 210000001847 Jaw Anatomy 0.000 description 4
- 230000005484 gravity Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 1
- 210000004197 Pelvis Anatomy 0.000 description 1
- 230000000903 blocking Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006011 modification reaction Methods 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000000284 resting Effects 0.000 description 1
- 230000000717 retained Effects 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
Abstract
Some wheelchair users have muscular spasms when travelling over bumps or an uneven surface generally. These are a reflex response to vibrations running up through the chair to the occupant. As a result, the occupant may thrash their body, putting strain on the chair and therefore cause premature wear and tear. Further, some wheelchair users are known to forcefully bang their heads against the wheelchair’s backrest, or push their feet against the wheelchair’s foot rests and drive their back into the backrest. These movements also cause undue strain on the wheelchair and premature wear and tear. It is an object of a preferred form of the invention to address some of the problems. The invention may be embodied in a wheelchair 1 comprising wheels 2, a support frame that engages with the wheels, a seat base 30 fitted to the frame, and suspension 33 between the frame and base. The base is adapted to move with respect to the frame when a human occupant is seated such that the suspension dampens body weight force between the base and frame. ar and tear. Further, some wheelchair users are known to forcefully bang their heads against the wheelchair’s backrest, or push their feet against the wheelchair’s foot rests and drive their back into the backrest. These movements also cause undue strain on the wheelchair and premature wear and tear. It is an object of a preferred form of the invention to address some of the problems. The invention may be embodied in a wheelchair 1 comprising wheels 2, a support frame that engages with the wheels, a seat base 30 fitted to the frame, and suspension 33 between the frame and base. The base is adapted to move with respect to the frame when a human occupant is seated such that the suspension dampens body weight force between the base and frame.
Description
TITLE
A Wheelchair
FIELD OF INVENTION
This invention relates to a wheelchair incorporating suspension.
BACKGROUND
It is known for some wheelchair users to have muscular spasms when travelling over
bumps or an uneven surface generally. These are a reflex response to vibrations
running up through the chair to the occupant. As a result the occupant may thrash
their body, putting strain on the chair and therefore cause premature wear and tear.
Further, some wheelchair users are known to forcefully bang their heads against the
wheelchair’s backrest, or push their feet against the wheelchair’s foot rests and drive
their back into the backrest. These movements also cause undue strain on the
wheelchair and premature wear and tear.
OBJECT
It is an object of preferred embodiments of the invention to go some way towards
addressing the above problem. While this applies to preferred embodiments, it should
be understood that the object of the ion per se is simply to e the public with
a useful choice. Therefore, any objects, advantages or benefits applicable to preferred
embodiments should not be taken as a tion on any claim expressed more
broadly.
SUMMARY OF ON
A wheelchair sing
• wheels;
• a support frame that engages with wheels;
• a seat base fitted to the frame; and
• suspension between the frame and base;
terised in that the base is adapted to move with t to the frame when a
human occupant is seated on the base such that the suspension dampens body weight
force between the base and frame.
Optionally the seat base is detachably fitted to the support frame.
Optionally a plurality of clamps are fitted to the support frame, at least some of which
have g levers that pivot to lock the base on the frame.
Optionally wherein the seat base includes at least one rear saddle, at least two
tor tabs and at least one front saddle, all engaged with the support frame.
Optionally each connector tab has a pin that engages a slot of corresponding clamp
that is in turn secured to the frame.
Optionally the front saddle is substantially rigid to limit the movement of the seat base.
Optionally the rear saddle is resilient such that at least the rear of the seat base can
move up and down on the rear saddle with respect to the t frame.
Optionally a backrest is secured to the frame by way of a set of lever arms at each
side, each set comprising one lever arm secured to the back rest (directly or indirectly)
and another lever arm secured to the frame (directly or indirectly), for each set at least
one of the lever arms is adapted to pivot with t to the other to enable adjustment
of incline of the backrest when an occupant of the seat presses their back against the
backrest.
Optionally for each set one of the lever arms is fastened to the backrest by way of a
bracket and the other is fastened to the support frame by way of a clamp.
Optionally the backrest is also d to the support frame (directly or indirectly) by a
damper at each side, each damper comprising a piston that retards recline of the
backrest to absorb bodyweight or muscle generated wear and tear force on the frame
as the backrest moves to a recline position.
Optionally in each case the damper comprises a spring that tensions when the
backrest moves to the recline position to retard the recline.
Optionally in each case the damper ses a housing around the piston, the
housing being adapted to move back and forward with t to the piston when the
backrest reclines and uently moves to a non-reclined position.
Optionally in each case the piston comprises a pin outside the housing, arranged such
that the pin s a clamp that in turn secures the damper to the support frame.
Optionally each case the piston’s pin has been slid into an upwardly opening track.
Some preferred embodiments of the invention will now be described by way of
example and with reference to anying drawings, of which:
Figure 1 is an isometric view of a wheelchair, partially assembled;
Figure 2 is an isometric view of backrest forming part of the wheelchair;
Figure 3 a side cross-sectional view of a damper forming part of the
wheelchair;
Figure 4 is an isometric part cross-sectional view illustrating how the
damper relates to the backrest;
Figure 5 is a side view of the wheelchair partially assembled;
Figure 6 is an isometric view of a base plate and seat frame forming part
of the wheelchair, in the process of being assembled;
Figure 7 is a isometric view of the seat base plate;
Figure 8 is an isometric view of a clamp used to secure the wheelchair’s
backrest to its frame; and
Figure 9 is an alternative ric view of the clamp.
DETAILED DESCRIPTION
Referring to Figure 1, the wheel chair 1 has a pair of large rear wheels 2, a pair of
smaller swivelling front wheels 3, a support frame comprising a backrest frame 4 and a
seat frame 5. These frames 4,5 may or may not be integral. The wheels engage the
support frame; they t to it directly. As shown, the backrest frame 4 has a pair of
spaced uprights 6 that turn over at their upper end to provide handles 7. The uprights
6 support a plate like backrest 8.
Each upright 6 is fitted with an upper clamp 9 and a lower clamp 10, and each side of
the backrest 8 is fitted with upper and lower L-brackets 11, 12. Each upper clamp 9 is
y but adjustably ted to the frame 4, and each upper bracket 11 is rigidly but
adjustably connected to the backrest 8. Both are connected to a damper 13. Further,
each lower clamp 10 is rigidly but adjustably connected to the frame 4, and each lower
L-bracket 12 is rigidly but adjustably connected to the st 8. As shown, each
lower clamp 10 is ted to a corresponding one of the lower L-brackets 12 by way
of a lever set 14.
Referring to Figure 2, each lever set 14 comprises an inside lever arm 15 and an
outside lever arm 16. The top of each inside lever arm 15 is rigidly but adjustably
fixed to a respective lower L- bracket 12 by bolts 19. The top of each e t
is fixed to a respective lower clamp 10 (the clamps 10 are shown in Figure 1) by one or
more pins, the position of which is indicated at labels 20 and 21. The le ver arms 15,
16 are connected to one another at their lower end by pivot pin 17. The arrangement
is such that at least one or other of the levers 15, 16 can pivot about the pin 17 with
respect to the other.
Still with Figure 2, each damper’s housing 18 is rigidly but ably fixed to the
corresponding upper L-bracket 11 by bolts 22. In each case the damper 13 also has a
piston 24, an end of which extends from the housing 18 to attach to a corresponding
upper clamp 9 (the clamps 9 are shown in Figure 1).
Figure 3 illustrates detail of the internal parts of the damper 13. When the damper is
at rest, most of the piston 24 resides within the housing 18. However, when in use the
housing 18 can be forced by backwards movement of the backrest to move along the
piston (to the left in the drawing) to expose more of the piston 24. As this happens a
spring 25 within the housing, i.e. acting between the housing and piston, is put under
tension to retard or cushion backwards movement of the backrest. This tension serves
to return the damper g 18 to its original resting disposition when the force acting
against the spring is relaxed.
With further reference to Figure 3, the damper 13 has an internal stopper 26 at one
end of the housing. The ement is such that the spring bears against the stopper,
but more so when put under tension. The other end of the spring bears against an
internal support 27 arranged near the opposite end of the housing 18. The t 27
helps keep the piston 24 and spring 25 in position within the housing. The support 27
moves with the g to compress the spring between the support and the stopper
26. As also shown, the piston incorporates a pin 28 and it is this that serves to attach
the damper to the upper clamp 9 (again, the clamps 9 are shown in Figure 1).
When in use the housing 18 around the piston 24 moves forwards and backwards in
response to bodyweight or muscle driven force from the wheelchair user against the
backrest 8. The spring 25 compresses as the piston 24 becomes more exposed , but
returns into its original disposition once the force is d. This s the stress
impact caused by ul body movements by the seat user. As the housing 18 moves
forwards and backwards, the pin 28 is able to move up and down slightly in the
associated upper clamp 9, which helps reduce stress on the backrest frame 4.
ing again to Figure 2, when the back rest es in use, the inner lever arm 15
in each case pivots with respect to the outer lever arm 16. The lever arms 15, 16 are
placed at or near the bottom of the backrest support 4 so that at the bottom of the
backrest, nt is primarily only a recline motion, i.e. as opposed to the more
significant swinging motion at the top of the backrest. This limited movement near the
seat base prevents or reduces movement of the occupant’s pelvis. This assists in
keeping the occupant safely within the seat. In some embodiments the lever arms 15,
16 may have a spring acting between them to help reduce stress on at least the
backrest frame 4.
ably both sides of the back rest 8 are connected to the backrest frame 4 in the
same way. The lever arms 16, 17 working in association with the dampers 13 enable
the occupant to have a smoother ride and to reduce wear and tear on the wheelchair.
Further, when the hair is in use and the weight of the person is shifting forwards
and backwards, the backrest 8 moves, tically, in sympathy with this to a limited
extent.
Figure 4 gives more detail of the relationship between the damper 13 and the backrest
8. In each case the bolts 22 are secured within slots 23 of the L- brackets 11. The
piston 24 sits partially within the housing 18 with the pin 28 outside the housing. The
spring 25 is shown at rest with the stopper 26 spaced from the support 27.
Referring to Figure 5, the wheel chair’s seat frame 5 has a horizontal bar 29 at each
side, and these support a plate like seat base 30. More specifically, the base 30
engages the frame 5 by way of a front saddle 31 at each side, a connector tab 32 at
each side, a rear saddle 33 at each side and a clamp 34 at each side. Each tab 32
engages a corresponding one of the clamps 34.
Figure 6 provides further detail of the way the seat base 30 fits to the frame 5. The
clamps 34 are releasably ed to the horizontal bars 29 and the front and rear
saddles 31, 33 sit on those bars 29. To facilitate a snug fit, the saddles 31, 33 have a
curved recess mentary to, and that engages, the bars 29. The front saddles 31
are preferably made of a hard non-metallic synthetic material, for example Nylon, while
the rear s 33 are ably made of a softer more cushioning material such as
rubber. The front saddles 31 resist movement of the seat base 30, and the rear
saddles 33 are able to resiliently compress under downward force to provide a
dampening or cushioning effect with respect to the frame 5 when someone sits on the
base 30. Put another way, the rear saddles 33 provide for suspension between the
seat base 30 and the seat frame 5.
Still with Figure 6, Each connector tab 32 has an inwardly extending pin 35 that slides
into a vertical slot 36 forming part of ponding seat clamp 34 (the inward
extension of the pin 35 is not visible for the tab in the foreground of the drawing). As
the pin 35 moves to the bottom of the slot it pushes against a pivoting locking lever 37,
displacing it as it passes. The locking lever 37 is weighted to then pivot-return under
gravity to its original position blocking the slot 37. This serves to retain the pin 35 in the
slot, and therefore the seat base 30 with respect to the frame 5. To release the pin 35
from the slot 36, the lever 37 can be pivoted out of the way of the pin 35 by hand, and
the pin 35 then raised up out of the slot. In each case, when g at the bottom of
the slot 36, the pin 35 has a little up and down and side to side give, to accommodate
compression movement at the rear saddles 33.
Figure 7 illustrates further detail for the seat base 30 and related parts prior to
installation on the seat frame 5.
Figure 8 illustrates the way the upper clamps 9 engage the backrest frame 4 in more
detail. In this regard each clamp 9 has resilient jaws 38 that wrap around one of the
uprights 6 and can be ned by bolts between the jaws (not shown). The clamp 9
incorporates a track rail 39 with a slot 40 that receives and retains the pin 28 of
the piston (see Figures 2 and 3 for the pin 28). While retained in the rail 39, the piston
pin 28 can slide up and down a little to e a little give and reduce occupant bodymovement
generated strain on the frame 4.
Figure 9 illustrates detail of how the lower clamps 10 engage with the backrest frame
4. Each clamp 10 has resilient jaws 41 that clip onto a frame upright 6 and may be
tightened by a bolt (not shown) n the jaws. The clamp 10 incorporates a shorttrack
rail 42 with an upright slot 43, and a locking lever 44. The ement is such
that in each case the pin 20 of the outside lever arm 16 (see Figure 2) slides down into
the slot 43. As it does this it pushes against the locking lever 44 causing it to pivot out
the way. When the pin is below the lever 44 the lever pivots back under gravity to
block the slot 43 and lock in the pin 20. The lever 44 can be subsequently moved out
of the way by hand to enable the pin 20 to be released from the clamp 10. If the outer
lever arm 16 has two of the pins 20, 21 (see Figure 2) then they may both be below the
locking lever when it closes the slot 43.
In some embodiments of the invention the dampers 13 may be replaced by spring
cushioning lever sets the same or similar to those bed above, although the
dampers are the preferred option.
In terms of disclosure, this nt hereby envisages each item, e or step
mentioned herein, in combination with one or more of any same or other item, feature
or step disclosed herein, in each case regardless of whether the combination is
claimed.
While some preferred forms of the invention have been described by way of example it
should be appreciated that modifications and improvements can occur without departing
from the scope of the appended claims.
Claims (15)
1. A wheelchair comprising • wheels; 5 • a support frame that engages with the wheels; • a seat base fitted to the frame; and • suspension between the frame and base; characterised in that the base is adapted to move with respect to the frame when a human occupant is seated on the base such that the suspension dampens body 10 weight force between the base and frame.
2. A wheelchair according to claim 1, wherein the seat base is detachably fitted to the support frame. 15
3. A wheelchair according to claim 1, wherein a plurality of clamps are fitted to the support frame, at least some of which have locking levers that pivot to lock the base on the frame.
4. A wheelchair according to claim 1, 2 or 3, wherein the seat base includes at least 20 one rear saddle, at least two connector tabs and at least one front saddle, all engaged with the support frame.
5. A wheelchair according to claim 4, wherein each connector tab has a pin that engages a slot of corresponding clamp that is in turn secured to the frame.
6. A wheelchair ing to claim 4 or 5, wherein the front saddle is substantially rigid to limit the movement of the seat base.
7. A wheelchair ing to 4, 5 or 6, wherein the rear saddle is resilient such that at 30 least the rear of the seat base can move up and down on the rear saddle with respect to the support frame.
8. A wheelchair ing to any one of the preceding claims, sing a backrest that is secured to the frame by way of a set of lever arms at each side, each set 35 comprising one lever arm secured to the back rest tly or ctly) and another lever arm secured to the frame (directly or indirectly), for each set at least one of the lever arms is adapted to pivot with respect to the other to enable adjustment of incline of the backrest when an occupant of the seat presses their back against the backrest.
9. A wheelchair according to claim 8, wherein for each set one of the lever arms is 5 ed to the backrest by way of a bracket and the other is fastened to the support frame by way of a clamp.
10. A hair according to claim 8 or 9, wherein the backrest is also secured to the support frame (directly or indirectly) by a damper at each side, each damper 10 comprising a piston that retards recline of the backrest to absorb bodyweight or muscle generated wear and tear force on the frame as the backrest moves to a recline position.
11. A wheelchair according to claim 10, wherein in each case the damper comprises a 15 spring that tensions when the backrest moves to the recline position to retard the recline.
12. A wheelchair according to claim 10 or 11, wherein in each case the damper comprises a housing around the piston, the housing being d to move back 20 and forward with respect to the piston when the backrest reclines and subsequently moves to a non-reclined on.
13. A wheelchair according to claim 12, wherein in each case the piston comprises a pin e the housing, ed such that the pin engages a clamp that in turn 25 secures the damper to the support frame.
14. A wheelchair according to claim 13, wherein in each case the piston’s pin has been slid into an upwardly opening track. 30
15. A wheelchair ing to claim 1, wherein: a) the seat base is ably fitted to the frame; b) a plurality of clamps are fitted to the support frame, at least some of which have locking levers that pivot to lock the base on the frame; c) the seat base includes at least one rear saddle, at least two connector tabs 35 and at least one front saddle all engaged with the support frame; d) each connector tab has a pin that engages a slot of corresponding clamp that is secured to the frame; e) the front saddle is substantially rigid to limit the movement of the seat base; f) the rear saddle is resilient such that the seat base can move up and down on the rear saddle with respect to the support frame; g) the wheelchair comprises a st that is secured to the support frame by 5 way of a set of lever arms at each side, each set comprising one lever arm secured to the back rest tly or indirectly) and another lever arm secured to the frame (directly or indirectly), for each set at least one of the lever arms is adapted to pivot with respect to the other to adjust the incline of the backrest when an occupant of the seat presses their back against the 10 backrest; h) for each set one of the lever arms is fastened to the backrest by way of a bracket and the other is fastened to the frame by way of a clamp; i) the backrest is also secured to the support frame (directly or indirectly) by a damper at each side, each damper comprising a piston that retards recline 15 of the backrest to absorb ight or muscle generated wear and tear force on the frame as the backrest moves to a recline position; j) in each case the damper comprises a spring that tensions when the st moves to the recline position to retard the e; k) in each case the damper comprises a housing around the piston, the 20 housing being adapted to move back and forward with respect to the piston when the backrest reclines and subsequently moves to a non-reclined position; l) in each case the piston ses a pin outside the g, and the pin engages a clamp that secures the damper to the support frame; and 25 m) in each case the piston’s pin has been slid into an upwardly opening track.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2021236483A AU2021236483A1 (en) | 2020-10-16 | 2021-09-22 | A wheelchair |
EP21199568.3A EP3984506A3 (en) | 2020-10-16 | 2021-09-28 | A wheelchair |
Publications (1)
Publication Number | Publication Date |
---|---|
NZ766300A true NZ766300A (en) |
Family
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