GB2544276A

GB2544276A - Height adjusting wheelchair

Info

Publication number: GB2544276A
Application number: GB1519771.8A
Authority: GB
Inventors: Rawlinson Paige Clive
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-11-09
Filing date: 2015-11-09
Publication date: 2017-05-17
Anticipated expiration: 2035-11-09
Also published as: GB201519771D0; GB2544276B

Abstract

A height adjustable wheelchair comprising a U shaped frame 1 having two long sections that form the front legs wherein the U frame forms the back of the chair 9, two further frame components that form the rear legs 2 wherein each is coupled and supported at one end by a sliding component 23 which are in turn coupled to the front legs 1 that facilitate the movement of rear legs radially along the length of front legs, and wheels 5 positioned on both front and rear legs. The frame will preferably use tubular aluminium and /or steel as the frame material. The chair may preferably use lithium batteries a s a means of suppling power to the electrically driven wheels. The seated area will preferably comprise an elastic flexible material. The wheels will also preferably have a braking system attached to the front wheels.

Description

Background - Introduction

Many people have temporary or permanent mobility-related disabilities that require the use of a wheelchair, walker, or other type of mobility equipment. Individuals with mobility limitations face many physical and psychological challenges associated with wheelchair use. For example, the task of moving to and from a bed ora chair, use of washroom amenities, cooking and preparing meals at home, reaching for objects in overhead cupboards, or even shopping at a super market. These present real physical challenges for many people with mobility-related disabilities, and lead to dependency on others.

In addition to these physical challenges, wheelchair users also suffer from social and psychological challenges associated with wheelchair use. For example, wheelchair users are at a lower vantage point than their standing peers. This lower vantage point means that wheelchair users are sometimes ignored in social situations. This lower and un-natural vantage point may create real or perceived disadvantages in some social situations. These physical and sociological challenges can lead wheelchair users to feel alienated or frustrated by their situation.

Existing wheelchairs and other mobility equipment do not adequately address the various physical and psychological challenges faced by those with mobility-related disabilities. Existing mobility equipment is usually utilitarian, unattractive, and often inconveniently heavy.

Summary

This summary is provided to introduce a simplified lightweight concept of a height-adjusting wheelchair, which is further described below in the detailed description. This summary is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining the scope of the claimed subject matter.

Existing height adjustable wheelchairs usually include a base frame coupled to and supported by four wheels. A seat assembly is positioned above and coupled to the base frame by a lifting mechanism for adjusting the height of the seat assembly relative to the base frame. The lifting mechanism often includes hydraulic lift cylinders/mechanical scissor actions coupled to the base frame and the seat assembly. Additional electric motors, batteries, fluid reservoirs and safety guards all add complexity and weight. Typically these chairs can weigh up to 50 kg

This disclosure is directed to an attractively designed, light weight, heightadjusting wheelchair, which allows the occupant of the wheelchair to adjust the height of the wheelchair seat over a wide range, in a simple and efficient manner. In the high setting the user is effectively at standing height, and can use a single leg - if available, to move and guide the chair. The use of electric powered front wheels is optional. The powered wheels can be controlled by a wireless controller, placed at any suitable location on the chair or remotely held by the user. The wheelchair offers news levels of utility and independence.

Notably the wheelchair is also useful for people without disability in situations where standing or walking on smooth flooring for extended periods of time such, as tradeshows and airports for example. Two legs can be used to propel and guide the wheelchair very effectively leaving the hands free, and because of enhanced maneuverability, the wheelchair can be usefully used in laboratories, studios, hair salons etc.

The larger than usual lightweight caster wheels allow easy movement over less than even surfaces and carpets.

The chair does not employ a high back rest, but has ample back support in the recumbent setting, and usefully allows the user to move on and off from the back of the chair by moving backwards onto a bed for example, as well as moving easily from the front of the chair in its elevated setting.

In addition, the chair can be used as a rolling walker, and can be collapsed for transport and storage. The design avoids using frame scissor/pivot construction with inherent pinch dangers. The standard weight is 4.8kg.

Brief description and operation

The user sits on a section of flexible seating material that is held by a sliding sub-frame at the front, and by the main frame at the rear.

To raise the seating position, the side handles are pulled back to the vertical position and then pushed and rotated forwards, this causes a section of the flexible seating material to be wound onto the sliding sub frame at the front, and this pulls the sub-frame up and backwards towards the rear along the radial curved sections of the main frame.

This is repeated until the desired seat height is achieved.

To lower the seat height, the handles are brought backwards beyond the vertical position to a pressure sensitive end stop, which progressively releases the wound flexible seating material according to the pressure applied. The weight of the user causes the sliding sub-frame to move forward and down along the radial curved sections of the main frame.

Therefore, it is a principal object of the present invention to provide a wheelchair that allows the user to simply and easily adjust the height of the chair over a wide range of height, and enable activities that were hitherto not practical or possible.

Brief description of the several views

Figure 1a shows the chair in use set at the lowest recumbent position.

Figure 1b shows the chair in use set at the high near standing position.

Figure 2a shows a side view of the chair in the lowest position with numerical indicators identifying the different elements of the design.

Figure 2b shows a top view of the chair in the lowest position with numerical indicators identifying the different elements of the design.

Figure 3a shows a side view of the chair in the highest position with numerical indicators identifying the different elements of the design.

Figure 3b shows a top view of the chair in the highest position with numerical indicators identifying the different elements of the design.

Figure 4a shows a rear sectional view of the wrap spring clutch arrangement with the operating lever in the vertical winding mode position, with numerical indicators identifying the different elements of the design.

Figure 4b shows a sectional side view on F-F of the wrap spring clutch arrangement with the operating lever in the vertical winding mode position, with numerical indicators identifying the different elements of the design.

Figure 5a shows a rear sectional view of the wrap spring clutch arrangement with the operating lever in the rear release position, with numerical indicators identifying the different elements of the design.

Figure 5b shows a sectional side view on F-F of the wrap spring clutch arrangement with the operating lever in the rear release position, with numerical indicators identifying the different elements of the design.

Figure 6 shows the wheel chair set in the high position being used as a rolling walker.

Figures 7a to 7c shows how the user can get into the chair from sitting on the floor.

Figures 7d and 7e shows how the unassisted user can get on and off from the back of the wheel chair at different heights, to access washroom facilities and beds for example.

Figure 7f shows a typical seating position at a table.

Figure 7g shows how the high setting can give access to shelves and work surfaces at home.

Figure 7h shows how luggage can be transferred.

Figure 7i shows human interaction scenario.

Description of the preferred embodiment

Figure 2b shows a top view, the chair has a tubular mainframe (1) that is formed into a compound U shape with caster wheels (5) attached to each end of the front legs.

Figure 2a is a side view of the mainframe showing that the legs are also formed in a plane perpendicular to the U plane shown in Figure 2b, to form a radial section over the entire length of each leg. Importantly the U section (9) also has a re-curve in the same plane as the radial sections of the legs. This re-curve section is used to give back support when the seat is in the high position shown in Figure 3a.

Figure 2a also shows the sub-frame consisting of two radially curved rear legs (2) with caster wheels attached at one end (6) and attached to a sliding component (23) at the other end. The two sliding components (23) shown in Figure 2b support a rotatable tube (8) that is rotated by the handles (22) via one-way wrapspring clutches shown in Figure 4(a). The sliding components (23) allow the sub-frame to move radially along the mainframe front legs (1) between position (3) Figure 2a, and position (11) Figure 3a.

To raise the seat height, the side handles are used to wind the strip of flexible seat material onto the rotatable tube (8), to lower the seat height, the rotatable tube (8) is allowed to unwind in a controlled manner. Figure 4a shows a rearview section of the spring-wrap clutch arrangement that allows these operations to be performed. Figure 4b shows the side view in part section along F-F.

Figure 4b shows the handle (22) in the vertical position and being moved forward in direction of arrow A. The wrap-spring clutch (25) is fixed to the handle (22) by a radial castellation formed into one end of the wrap-spring component (26). As the outer end of the wrap-spring (26) is rotated forward, the tail end of the spring (21) tightens on the tube (8) and causes it to rotate forward with the handle (22). The flexible seat material (17) is fastened and wound onto the tube (8) in the direction shown by arrow D. After a rotational movement of 90 degrees for example, the handle is returned back to the start position. Moving the handle backwards causes the tail end of the spring (21) to no longer grip the tube (8) and slides on the tube (8) back to the start position. The tube (8) is prevented from moving backwards by means of wrap-spring (24). The castellated end (27), is held by the sliding member (23), and the tail end of the wrap-spring (19) prevents backward rotation of tube (8).

To release the wrap-spring (24) and allow the tube (8) to rotate backwards and unwind the flexible seat material (17), the handle (22) is brought backwards beyond the vertical position as shown in Figure 5b. The wrap-spring end (21) then engages with lever (20), which is pivoted about its mid poind. The engagement causes the lever (20) to rotate about its mid point and engage with the end (19) of wrap-spring (24). As the wrap-spring end (19) is engaged, the grip on the tube (8) is progressively released allowing the controlled unwinding of the flexible seating material (17) in direction shown by arrows E.

Figure 5a also shows a contact roller (10) that is fixedly attached to tube (8) that is in rolling contact with the mainframe (1) shown in Figure 5b, and is used to reduce frictional resistance with the sliding component (23).

The handles and wrap-spring arrangements are identical on each end of the tube (8), and can be operated independently.

Claims

1. A height adjustable wheel chair comprises of a U shaped frame (1) the two long sections of said U frame are both formed radially in a perpendicular or near perpendicular plane to said U frame and mirror each other, and are employed as front legs, the U section of said U frame forms the back of the chair (9), two further frame components are used to form rear legs (2) and each are coupled and supported at one end to a sliding component (23) which are in turn coupled to said front legs (1) in a manner that allows said rear legs (2) to move radially along the length of said front legs (1), suitable wheels (5) are attached to both said front and rear legs, a rotatable frame element (8) is supported by both said sliding components (23), a flexible strip of seating material is fastened and partly wound onto said rotatable frame element (8) and is stretched to form a seating section (17) and is fastened to and supported by said back of chair (9), handles (22) are coupled and supported at each end of said rotatable frame element (8) and can be used to wind, hold and release said flexible strip of seating material (17).

2. The wheel chair in claim 1 uses said handles (22) connected via wrap-spring clutches (24) and (25) to each end of said rotatable frame element (8) and are used to rotate, hold and progressively release said rotatable frame element (8) with the aid of the release pivot (20), controlling the length of the flexible seating material, which in turn raises or lowers said seating material section (17).

3. The wheel chair in claims 1 and 2 use tubular aluminium and/or steel as the frame material.

4. The wheel chair in claims 1,2 and 3 use large diameter castor wheels of around 200-300mm in diameter with a caster off-set of around 100mm, and these are detachable using a quick release locking system.

5. The wheel chair in claims 1,2 and 3 use large diameter wheels of around 200-300mm in diameter and that two or more wheels may be electrically driven, and these are detachable using a quick release locking system.

6. The wheel chair in claims 1,2 and 3 hold lithium-iron batteries within the frame tubing to supply power to electrically driven wheels.

7. The wheel chair in claims 1,2 and 3 use wrap-springs fabricated or machined from steel or aluminium and electro-less nickel coated.

8. The wheelchair in claims 1,2 and 3 use an elastic flexible material for the seat (17).

9. The wheel chair in claims 1,2 and 3 use a quick release attachment method to secure the seat (17) to elements (8) and (9).

10. The wheel chair in claims 1,2 and 3 have a braking system attached to two or more of the wheels.

11. The wheel chair in claims 1,2 and 3 have either one or both front legs (2) and/or caster fittings (5) adapted for foot and/or leg rests.

12. The wheel chair in claims 1,2 and 3 use a pair of contact rollers (10) that are fixedly attached to tube (8) and are in rolling contact with the mainframe (1).

13. The rear legs (2) are detachable using a quick release locking system.

14. When the wheel chair is set in the low position, the caster angle for the rear wheels is angled so as to prevent caster steering, this restricts rear wheel movement to either side and provides a more stable platform for moving on or off the rear of the wheelchair.

15. When the wheelchair is set in the high position, the caster angle for the front wheels is angled to reduce caster steering, and reduces the amount of front wheel lateral movement, allowing better clearance for leg assisted propulsion and steering.