GB2378929A

GB2378929A - Invalid chair with propulsion unit

Info

Publication number: GB2378929A
Application number: GB0120609A
Authority: GB
Inventors: David Hayes Jackson; Russ Critcher; Derek John Slaugher
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-08-24
Filing date: 2001-08-24
Publication date: 2003-02-26
Anticipated expiration: 2021-08-24
Also published as: GB0120609D0; GB2378929B; WO2003017906A1

Abstract

An invalid chair 2 comprises a power source, a motor, a gearbox and control circuitry encapsulated in a propulsion unit 24, which may be urged into engagement with the ground by a spring, or preferably two springs, acting between the chassis and the unit's spindle 26. Alternatively, springs may act between the chassis 4 and pivoting arms connected to the spindle ends 28,20. Each spring may be enclosed in a telescoping damping cylinder 36,38. An external battery may be provided to extend the range of operation and to act as a weight increasing the downwards force on the unit 24, which may be encapsulated as a sheet metal or plastic moulded hollow roller. The chair 2 may be propelled by handles 10,12 or by the occupant via rear wheels 18,20 or by the propulsion unit 24, via a speed control located on a hand grip. Folding of the chair 2 may be facilitated by detachment of the unit 24.

Description

IMPROVEMENTS IN MOTORISED INVALID CHAIRS This invention is concerned with improvements in or relating to motorised invalid chairs and is particularly, though not exclusively, concerned with improvements in or relating to motorised invalid chairs provided with a propulsion unit having encapsulated therein a power source, a motor, a gear box and control circuitry.

Motorised invalid chairs are presently available in manifold shapes and sizes depending upon the infirmity of the person occupying the chair.

One thing that motorised invalid chairs have in common; however, is the complexity of the propulsion unit associated therewith. A chair of this type must be provided with a power source, rechargeable or otherwise, a motor to be driven by the power source, a gearbox for changing the speed of a propulsion unit connected to the motor, and control circuitry.

In addition to readily available motorised invalid chairs, many other invalid chairs are wholly reliant upon the muscle power of the occupant of the invalid chair to propel and control the chair. Otherwise the invalid chair may be propelled and controlled by a person who is assisting the infirm person by pushing the invalid chair.

It is one of the objects of the present invention to provide an improved motorised invalid chair in which the propulsion unit is less complex than those provided in currently available invalid chairs.

Thus, the present invention provides a motorised invalid chair comprising a power source, a motor, a gearbox, control circuitry and a propulsion unit for propelling the chair in use, characterised in that the power source, motor, gearbox and control circuitry are wholly encapsulated in the propulsion unit.

Preferably, the chair comprises propulsion unit engaging means whereby, when the chair is in use, the propulsion unit is urged into engagement with a surface over which the chair is to be propelled.

Conveniently, the propulsion unit engaging means comprises at least one compression spring acting between a chassis of the chair and a spindle of the propulsion unit.

Preferably, the propulsion unit engaging means comprises two compression springs, each compression spring acting between the chassis of the chair and a respective opposite end portion of the spindle, the compression springs each being conveniently enclosed in associated telescoping damping cylinders.

Preferably, each of the damping cylinders is positioned between the chassis of the chair and an associated one of two pivotal arms, opposite end portions of which arms are connected, one each, to opposite ends of the propulsion unit spindle.

The invalid chair of the present invention also comprises a speed control located on a hand-grip of the invalid chair, the speed control being connected to the control circuitry by a primary line.

In one preferred embodiment provided by the present invention the propulsion unit is provided by a hollow roller in which the power source, motor, gearbox and control circuitry are wholly encapsulated as aforesaid, the propulsion unit being conveniently moulded from a plastic material.

Conveniently, the propulsion unit is readily detachable from the invalid chair in order to facilitate the folding of the chair for storage purposes and transport thereof.

There now follows by way of example of the invention a detailed description of a motorised invalid chair, which description is to be read with reference to the accompanying drawings in which: Figure 1 is a diagrammatic side elevation of the invention; and, Figure 2 is an end elevation of the chair as seen in the direction of the arrow i) in Figure 1.

Invalid chairs come in many different formats and may be motorised for control by the occupant or they may be powerless and therefore rely on the muscle power of the occupant or an person assisting the occupant in order to propel the chair.

The motorised invalid chair 2 provided by the present invention is designed to make life easier for the person occupying the chair and/or for the person assisting the chairs occupant in propelling the chair.

Thus, the motorised invalid chair 2 is of conventional design insofar that it has a chassis 4, provided with a seat 6, a footrest 8, handles 10 and 12, pivotally mounted front wheels 14 and 16 and rear wheels 18 and 20, see Figures 1 and 2.

The chair 2 is also provided with a propulsion unit 22 formed as a moulded hollow roller 24 of plastic material.

The roller 24 has a drive spindle 26 opposite ends 28 and 30 of which extend from left and right hand ends 28 and 30 of the roller 24, see Figure 2.

The spindles 26 IS supported by two telescoping cylinders 36 and 38, which are associated one each with the spindle ends 32 and 34 respectively, see Figure 2.

The cylinders 36 and 38 each house a compression spring, not shown, for a purpose to be described hereinafter.

Upper end portions 40 and 42 of the telescoping cylinders 36 and 38 are mounted on respective left and right hand brackets 44 and 46 of the chassis 2, see Figure 2, which brackets 44 and 46 are fixedly mounted on the chassis 4.

Thus, it will be appreciated, the compression springs contained in the telescoping cylinders 36 and 38 urge the roller 24 into contact with the surface 48 over which the chair is to be propelled.

The roller 24 is readily detachable from the telescoping cylinders 36 and 38 in order to facilitate the folding of the invalid chair 2 for storage and transportation thereof.

From the foregoing it will be appreciated that the improved motorised invalid chair, provided by the present invention, makes life somewhat easier for the user and for the assistants that help the user of the chair in that: a) the chair is readily affordable because It is of less complex construction than a conventional motorised invalid chair; b) the propulsion unit thereof greatly improves the mobility of the user; and, c) the ability to readily remove the propulsion unit from the chassis of the chair enables quick and easy folding of the chair for storage and transport thereof.

Whereas the propulsion unit engaging means has been described as being provided by compression springs housed in telescoping cylinders, acting directly between the spindle of the propulsion unit and brackets fixedly mounted on the chassis; in an alternative arrangement, the spindle may be connected, at its opposite ends thereof, to an

associated one of a pair of pivotal arms each of which is acted upon by an associated compression spring.

Other modifications may be made within the scope of the invention; for example, provision may be made to augment the force applied to the propulsion unit by the compression springs thereby ensuring adequate frictional contact between the propulsion unit and the surface over which the invalid chair is to be propelled.

Thus, the force applied by the compression springs may be augmented by a weight located over the propulsion unit. Such weight may be in the form of an external battery utilised to extend the range of the motorised invalid chair.

Further amendments may include the roller 24 being made of sheet metal rather than a moulding from plastic.

Claims

CLAIMS 1. A motorised invalid chair comprising a power source, a motor, a gearbox, control circuitry and a propulsion unit for propelling the chair when in use, characterised in that the power source, motor, gearbox and control circuitry are wholly encapsulated in the propulsion unit.
2. A motonsed invalid chair according to Claim 1, characterised in that the chair comprises propulsion unit engaging means whereby, when the chair is in use, the propulsion unit is urged into engagement with a surface over which the chair is to be propelled.
3. A motorised invalid chair according to Claim 2, characterised in that the propulsion unit engaging means comprises at least one compression spring acting between a chassis of the invalid chair and a spindle of the propulsion unit.
4. A motorised invalid chair according to Claim 4, characterised in that the propulsion unit engaging means comprises two compression springs, each compression spring acting between the chassis of the chair and a respective opposite end portion of the spindle.
5. A motorised invalid chair according to claim 4, characterised in that the compression springs are each enclosed in a telescoping damping cylinder.
6. A motorised invalid chair according to Claim 5, characterised in that each of the damping cylinders is positioned between the chassis of the invalid chair and an associated one of two pivotal arms, opposite end portions of which arms are connected, one each, to opposite ends of the propulsion unit spindle.
7. A motorised invalid chair according to any one of the preceding claims, characterised in that the chair comprise a speed control located on a hand-grip of the invalid chair, the speed control being connected to the control circuitry by a primary line.
8. A motorised invalid chair according to any one of the preceding claims, characterised in that the propulsion unit is provided by a hollow roller in which the power source, motor, gearbox and control circuitry are encapsulated.

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9. A motorised invalid chair according to any one of the preceding claims, characterised in that the propulsion unit is moulded from plastic material.
10. A motorised invalid chair according to any one of the preceding claims, characterised in that the propulsion unit is readily detachable from the invalid chair in order to facilitate the folding of the chair for storage purposes and transport thereof.
11. A motorised invalid chair substantially as herein described with reference to the drawings.