US 8,408,598 B2Granted

Anti-tip system for a power wheelchair

AssigneePride Mobility Products Corporation

InventorsJames P. Mulhern, Ronald Levi, Christopher E. Grymko

Life of this patent

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Abstract

An anti-tip system is provided for improving the stability of a powered vehicle, such as a powered wheelchair. The vehicle includes a drive-train assembly pivotally mounted to a main structural frame. A suspension system biases the drive-train assembly and its connected anti-tip wheel to a predetermined resting position. The drive-train assembly bi-directionally rotates about a pivot in response to torque applied to or acceleration forces on the vehicle. A linkage arrangement is provided and is characterized by a suspension arm pivotally mounting to the main structural frame about a pivot at one end thereof and an anti-tip wheel at the other end. The linkage may further include at least one link operable to transfer the bi-directional displacement of the drive-train assembly to the suspension arm. The link may include a bell crank member and/or may be resiliently compressible.

Claims13

Dependent claims

A wheelchair comprising:

a frame;
a pair of drive wheels defining a drive wheel axis;
a drive assembly operatively coupled to at least one drive wheel of the pair of drive wheels, the drive assembly configured to rotate the at least one drive wheel about the drive wheel axis to thereby cause the wheelchair to move relative to a surface that defines a ground plane;
an arm pivotably mounted to the frame at an arm pivot axis;
and
a caster wheel coupled to the arm, the caster wheel defining a rotational axis about which the caster wheel rotates,
wherein the vertical position of the arm pivot axis with respect to the ground plane when the caster wheel and the drive wheel are in contact with the surface is spaced from and positioned relatively below a straight line drawn between the drive wheel axis and the rotational axis of the caster wheel, and
wherein the arm is operatively coupled to the drive assembly such that the arm is configured to pivot about the arm pivot axis in response to torque created by rotation of the at least one drive wheel by the drive assembly so as to cause a responsive vertical movement of the caster wheel.

5 more elements

A wheelchair comprising:

a frame;
a pair of drive wheels defining a drive wheel axis;
a drive assembly operatively coupled to at least one drive wheel of the pair of drive wheels, the drive assembly configured to provide power to the at least one drive wheel to rotate the drive wheel about the drive wheel axis to thereby cause the wheelchair to move relative to a surface that defines a ground plane;
an arm pivotably mounted to the frame at an arm pivot axis;
and
a caster wheel coupled to the arm, the caster wheel defining a rotational axis about which the caster wheel rotates,
wherein the vertical position of the arm pivot axis with respect to the ground plane when the caster wheel and drive wheel are in contact with the surface is spaced from and positioned relatively below a straight line drawn between the drive wheel axis and the rotational axis of the caster wheel, and
wherein the arm is operatively coupled to the drive assembly such that (i) the arm is configured to pivot about the arm pivot axis in response to torque created by rotation of the at least one drive wheel by the drive, and (ii) the arm is configured to pivot about the arm pivot axis in response to braking

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/464,099Filed 4 May 2012 · continuation
Priority: 8 Oct 2003
Published: US 2012/0217081 A130 Aug 2012
Granted: 2 Apr 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

A61G 5/10
Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs: parts, details or accessories
A61G 5/042
Having a specific drive-type: front wheel drive
A61G 5/043
Having a specific drive-type: mid wheel drive
A61G 5/06
Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs: with obstacle mounting facilities, e.g. for…

Family

Application60/509,649Us provisional application · filed 8 Oct 2003
Application60/509,495Us provisional application · filed 8 Oct 2003
Application10/962,014Parent of this continuation-in-part · filed 8 Oct 2004
Application11/180,207Parent of this continuation · filed 13 Jul 2005
Application12/170,876Parent of this continuation · filed 10 Jul 2008
Application12/780,318Parent of this continuation · filed 14 May 2010
Application13/010,006Parent of this continuation · filed 20 Jan 2011
US 2012/0217081 A1Pre-grant publication · published 30 Aug 2012
US 8,181,992 B2Parent of this continuation
US 7,931,300 B2Parent of this continuation
US 7,726,689 B2Parent of this continuation
US 7,413,038 B2Parent of this continuation
US 7,389,835 B2Parent of this continuation-in-part
Application11/180,207Parent of this continuation-in-part
US 2005/0077715 A1Published application
US 2006/0022445 A1Published application
US 2008/0265541 A1Published application
US 2010/0219623 A1Published application
US 2011/0108348 A1Published application
US 8,408,598 B2This patent

From the US filing history. Foreign family members aren’t listed.