Patent US5123495A successfully refreshed from Google Patents.
US5123495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wheelchair stair climbing control system
Assignee: QUEST TECHNOLOGIES Corp
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Filing: 1989-11-21
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Granted: 1992-06-23
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Expires: 2009-11-21
Abstract
Abstract The present invention provides a sensor for detecting the angle of an incline, such as a staircase, before it is reached by the wheelchair. A control signal is provided to a motor for tilting the seat to cause the seat to be tilted to a predetermined minimum safe angle before the wheelchair reaches the staircase. The minimum safe angle is an angle of tilt at which the wheelchair will not roll over if the tilting mechanism should fail to completely rotate the seat to a horizontal position and as the stairs are descended. The minimum safe angle is determined by the position of the center of gravity of the wheelchair which is affected by the users weight. If the seat does not achieve this minimum tilt, the wheelchair is prevented from going over the stairs.
Inventors
- 👤 Douglas J. Littlejohn
- 👤 John H. Hessler
- 👤 Baxter R. Watkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:05
CPC Classifications
A; A61; A61G; A61G5/00; A61G5/06; A61G5/061; A61G5/066; B; B62; B62D; B62D55/00; B62D55/06; B62D55/075; B66; B66B; B66B9/00; B66B9/06; B66B9/08; A61G2203/00; A61G2203/30; A61G2203/42; A61G2203/44; A61G5/10; A61G5/1056; A61G5/107; A61G5/1075; Y; Y10; Y10S; Y10S180/00; Y10S180/907; Y10S280/00; Y10S280/10; Y10S297/00; Y10S297/04
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
138 words
In a stair-climbing, personal transport vehicle having a seat, the improvement comprising: a sensor for detecting the angle of incline of a surface before said vehicle traverses said surface; means for adjusting a tilt of said seat; means for sensing the tile of said seat; and means, responsive to said sensor and said tilt sensing agent for preventing movement of said vehicle over said incline, if said incline exceeds a predetermined steepness, until said means for adjusting has tilted said seat to a predetermined minimum angle, including a means for calculating said minimum angle, based on said detected angle, the weight of a user and the center of gravity of said vehicle, to give a change in the center of gravity of said vehicle and a user sufficient to prevent said vehicle from rolling over on said incline.
Claim 2
Dependent Claim
138 words
In a stair-climbing, personal transport vehicle having a seat, the improvement comprising: a sensor for detecting the angle of incline of a surface before said vehicle traverses said surface; means for adjusting a tilt of said seat; means for sensing the tile of said seat; and means, responsive to said sensor and said tilt sensing agent for preventing movement of said vehicle over said incline, if said incline exceeds a predetermined steepness, until said means for adjusting has tilted said seat to a predetermined minimum angle, including a means for calculating said minimum angle, based on said detected angle, the weight of a user and the center of gravity of said vehicle, to give a change in the center of gravity of said vehicle and a user sufficient to prevent said vehicle from rolling over on said incline.
Claim 3
Dependent Claim
46 words
The apparatus of claim 1 further comprising: means for detecting an angle of inclination of said vehicle; and said means for adjusting a tilt of said seat being responsive to said angle of inclination to keep the bottom of said seat horizontal with respect to gravity.
Claim 4
Dependent Claim
34 words
The apparatus of claim 2 wherein said means for adjusting a tilt of said seat comprises: a shaft coupled to a support of said seat; and a seat tilt motor for driving said shaft.
Claim 5
Dependent Claim
17 words
The apparatus of claim 1 further comprising a position sensor for detecting a tilt of said seat.
Claim 6
Dependent Claim
72 words
The apparatus of claim 1 wherein said sensor for detecting an angle comprises a first sensor for detecting a distance traveled by said vehicle and a second sensor for detecting a distance from said sensor to a point in front of said vehicle to provide a depth measurement, said angle of incline being calculated by the combination of a change in said depth measurement and a change in distance of said vehicle.
Claim 7
Dependent Claim
162 words
A personal transport vehicle comprising: a track means for moving said vehicle over an inclined surface; a member coupled to said vehicle proximate an end of said vehicle, for cushioning a tilting movement of said vehicle; a tube coupled to one of said vehicle and said member; a piston extending into said tube and coupled to a one of said vehicle and said member not coupled to said tube; means for restricting the flow of a first fluid out of a first side of said tube to limit the speed at which the combination of said tube and said piston compresses; means for forcing a second fluid into a second side of said tube to force a compression of said piston and tube combination; and means for providing an increased flow of said first fluid out of said first side of said tube coincident with operation of said means for forcing to allow a quick compression of said tube and piston combination.
Claim 8
Dependent Claim
162 words
A personal transport vehicle comprising: a track means for moving said vehicle over an inclined surface; a member coupled to said vehicle proximate an end of said vehicle, for cushioning a tilting movement of said vehicle; a tube coupled to one of said vehicle and said member; a piston extending into said tube and coupled to a one of said vehicle and said member not coupled to said tube; means for restricting the flow of a first fluid out of a first side of said tube to limit the speed at which the combination of said tube and said piston compresses; means for forcing a second fluid into a second side of said tube to force a compression of said piston and tube combination; and means for providing an increased flow of said first fluid out of said first side of said tube coincident with operation of said means for forcing to allow a quick compression of said tube and piston combination.
Claim 9
Dependent Claim
19 words
The apparatus of claim 6 further comprising a solenoid activated latch for holding said member in an up position.
Claim 10
Dependent Claim
35 words
The apparatus of claim 6 further comprising a fluid reservoir coupled to said first side of said tube and a valve for restricting a flow between said first side of said tube and said reservoir.
Claim 11
Dependent Claim
23 words
The apparatus of claim 8 wherein said means for providing an increased flow comprises a bypass valve for bypassing said restricted flow valve.
Claim 12
Dependent Claim
11 words
The apparatus of claim 6 wherein said second fluid comprises air.
Claim 13
Dependent Claim
17 words
The apparatus of claim 6 wherein said first fluid comprises a mixture of water and ethylene glycol.
Claim 14
Dependent Claim
17 words
The apparatus of claim 6 further comprising a sensor for detecting an up position of said member.
Claim 15
Dependent Claim
17 words
The apparatus of claim 6 further comprising a sensor for detecting a down position of said member.
Claim 16
Dependent Claim
206 words
A personal transport vehicle comprising: track means for moving said vehicle over an inclined surface; a member coupled to said vehicle proximate an end of said vehicle, for cushioning a tilting movement of said vehicle; a tube coupled to one of said vehicle and said member; a piston extending into said tube and coupled to a one of said vehicle and said member not coupled to said tube; means for restricting the flow of a first fluid out of a first side of said tube to limit the speed at which the combination of said tube and said piston compresses, including a fluid reservoir coupled to said first side of said tube and a valve for restricting a flow between said first side of said tube and said reservoir; means for forcing air into a second side of said tube to force a compression of said piston and tube combination; a bypass valve for bypassing said restricted flow valve to provide an increased flow of said first fluid out of said first side of said tube coincident with operation of said means for forcing to allow a quick compression of said tube and piston combination; and a sensor for detecting an up position of said member.
Claim 17
Dependent Claim
206 words
A personal transport vehicle comprising: track means for moving said vehicle over an inclined surface; a member coupled to said vehicle proximate an end of said vehicle, for cushioning a tilting movement of said vehicle; a tube coupled to one of said vehicle and said member; a piston extending into said tube and coupled to a one of said vehicle and said member not coupled to said tube; means for restricting the flow of a first fluid out of a first side of said tube to limit the speed at which the combination of said tube and said piston compresses, including a fluid reservoir coupled to said first side of said tube and a valve for restricting a flow between said first side of said tube and said reservoir; means for forcing air into a second side of said tube to force a compression of said piston and tube combination; a bypass valve for bypassing said restricted flow valve to provide an increased flow of said first fluid out of said first side of said tube coincident with operation of said means for forcing to allow a quick compression of said tube and piston combination; and a sensor for detecting an up position of said member.
Claim 18
Dependent Claim
221 words
A personal transport vehicle comprising: track means for moving said vehicle over an inclined surface; a member coupled to said vehicle proximate an end of said vehicle, for cushioning a tilting movement of said vehicle; a tube coupled to one of said vehicle and said member; a piston extending into said tube and coupled to a one of said vehicle and said member not coupled to said tube; means for restricting the flow of a first fluid out of a first side of said tube to limit the speed at which the combination of said tube and said piston compresses; means for forcing a second fluid into a second side of said tube to force a compression of said piston and tube combination; means for providing an increased flow of said first fluid out of said first side of said tube coincident with operation of said means for forcing to allow a quick compression of said tube and piston combination; a sensor for detecting the angle of incline of a surface being traversed by said vehicle; means for adjusting a tilt of said seat in accordance with said incline; and means responsive to said sensor, for preventing movement of said vehicle over an incline of predetermined steepness until said means for adjusting has tilted said seat to a predetermined minimum angle.
Claim 19
Dependent Claim
221 words
A personal transport vehicle comprising: track means for moving said vehicle over an inclined surface; a member coupled to said vehicle proximate an end of said vehicle, for cushioning a tilting movement of said vehicle; a tube coupled to one of said vehicle and said member; a piston extending into said tube and coupled to a one of said vehicle and said member not coupled to said tube; means for restricting the flow of a first fluid out of a first side of said tube to limit the speed at which the combination of said tube and said piston compresses; means for forcing a second fluid into a second side of said tube to force a compression of said piston and tube combination; means for providing an increased flow of said first fluid out of said first side of said tube coincident with operation of said means for forcing to allow a quick compression of said tube and piston combination; a sensor for detecting the angle of incline of a surface being traversed by said vehicle; means for adjusting a tilt of said seat in accordance with said incline; and means responsive to said sensor, for preventing movement of said vehicle over an incline of predetermined steepness until said means for adjusting has tilted said seat to a predetermined minimum angle.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-23 | 1995-12-23 | 1996-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-23 | 1999-12-23 | 2000-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-23 | 2003-12-23 | 2004-06-23 | $7700.00 | Window Closed / Lapsed |