Vehicle having wheels and castors
AssigneeSunrise Medical GmbH
InventorsJohn Maria Verhaeg, Donald Brookes
Life of this patent
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Abstract
A vehicle such as a wheelchair having wheels by which the vehicle is propelled and steered and castors which support a proportion of the vehicle's weight, has its castors provided with biasing means which resists swivelling movement of the castors from the straight-ahead position thereby resisting an oversteer condition of the vehicle.
Claims20
A vehicle comprising a front part, a rear part, a left hand side part, and a right hand side part;
- a pair of wheels spaced laterally of the front part;
- means for driving said wheels whereby the vehicle is propelled and steered;
- a first castor wheel assembly mounted at the rear part along the right hand side part, a second castor wheel assembly mounted at the rear part along the left hand side part, each said castor wheel assembly comprising a ground-engaging wheel and means supporting said ground-engaging wheel for rotation about a substantially horizontal rotational axis and for swivelling movement about a substantially vertical swivelling axis, a biasing means for providing a resistance to swivelling of the ground-engaging wheel of the castor wheel assemblies from a straight-ahead position whereby said first castor wheel assembly has its biasing means arranged to cause a different resistance from said biasing means of said second castor wheel assembly and whereby said second castor wheel assembly has its biasing means arranged to cause a different resistance from said biasing means of said first castor wheel assembly in respect of like swivelling movements of the castor wheel assemblies, said biasing means comprising a cam and follower mounted for relative axial displacement in response to swivelling movement, and means for resisting said relative axial displacement of said cam and follower thereby resisting swivelling movement of the castor wheel assemblies.
A vehicle including a chassis having a front part, a rear part, a left-hand side, and a right hand side;
- a pair of front wheels spaced laterally of the chassis and mounted at the front part;
- a means for driving said front wheels whereby the chassis is propelled and steered;
- a first castor wheel assembly mounted at the rear part along the right hand side, a second castor wheel assembly mounted at the rear part along the left hand side, each castor wheel assembly comprising a ground-engaging castor wheel and means for supporting the ground-engaging castor wheel for rotation about a rotational axis and for swivelling movement in a clockwise and in a counter-clockwise direction about a substantially vertical swivel axis;
- and, a biasing means operatively engaging each said castor wheel assembly for providing resistance to like swiveling movements of the castor wheels from a straight-ahead position, wherein the second castor wheel assembly has its biasing means arranged to come into effect only when the chassis is traveling forwards and steering to the right, and wherein the first castor wheel assembly has its biasing means arranged to come into effect only when the chassis is traveling forwards and steering to the left.
A wheel chair comprising a chassis, a pair of wheels mounted for rotation at a front part of the chassis, a means for driving said wheels whereby the vehicle is propelled and steered by differential driving of the front wheels, and a pair of castor wheel assemblies mounted at a rear part of the chassis, each said castor wheel assembly including a ground-engaging castor wheel, a means for supporting said ground-engaging wheel for rotation about a substantially horizontal axis and for pivoting about a substantially vertical swivelling axis in a clockwise and a counter-clockwise direction, and a means for resisting the swivelling of the ground-engaging castor wheel in at least one of said clockwise and counter-clockwise directions, said means for resisting including biasing means incorporated in each castor wheel assembly for providing resistance to like swivelling movement thereof from a straight-ahead position, wherein a first castor wheel assembly of said pair of castor wheel assemblies has a biasing means arranged to cause a different resistance from a biasing means of a second castor wheel assembly of said pair of castor wheel assemblies and whereby said second castor wheel assembly has its biasing means arranged to cause a different resistance from said biasing means of said first castor wheel assembly, both resistances in response to like swivelling movements of the castor wheel assemblies.
Dependencies are inferred from the claim text.