US5871329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Powered wheelchair ramp for minivans
Assignee: US VANTAGE Co DBA VANTAGE MINIVANS AN ARIZONA Corp LLC
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Filing: 1997-05-21
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Granted: 1999-02-16
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Expires: 2017-05-21
Abstract
Abstract A powered wheelchair ramp includes a drive mechanism having a gear, a cam, and a lever arm keyed to a common shaft to prevent relative motion among these elements. An electric motor drives the gear through a clutch and the lever arm raises or lowers a folding ramp. Energy storage device engage the cam through a follower for storing energy as the ramp is lowered. The energy storage device also damps the motion of the ramp. When the ramp is raised, the energy storage device aids lifting the ramp. The torques applied to the common shaft are such that the net torque in either direction about the shaft is below a predetermined amount. The result is that the ramp can be raised and lowered easily, even by a single person in a wheelchair sitting beside the ramp. The clutch is released for manual operation and can engage at any point for powered operation.
Inventors
- 👤 Gregg Alan Tidrick
- 👤 David H. Eaton, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:10
CPC Classifications
A; A61; A61G; A61G3/00; A61G3/02; A61G3/06; A61G3/061; Y; Y10; Y10S; Y10S414/00; Y10S414/134
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
115 words
A drive mechanism for raising or lowering a ramp attached to a minivan, said mechanism comprising: a common shaft; a gear, a cam, and a lever arm attached to said common shaft for rotation together about the common shaft; wherein said lever arm is adapted to raise or lower the ramp as the lever arm rotates with said common shaft; an electric motor coupled to said gear for causing said gear to rotate; and energy storage means coupled to said cam for storing energy as said ramp is lowered and for releasing energy as said ramp is raised, said energy storage means operating independently of said motor for assisting in raising or lowering said ramp.
Claim 2
Dependent Claim
115 words
A drive mechanism for raising or lowering a ramp attached to a minivan, said mechanism comprising: a common shaft; a gear, a cam, and a lever arm attached to said common shaft for rotation together about the common shaft; wherein said lever arm is adapted to raise or lower the ramp as the lever arm rotates with said common shaft; an electric motor coupled to said gear for causing said gear to rotate; and energy storage means coupled to said cam for storing energy as said ramp is lowered and for releasing energy as said ramp is raised, said energy storage means operating independently of said motor for assisting in raising or lowering said ramp.
Claim 3
Dependent Claim
23 words
The drive mechanism as set forth in claim 1 wherein said energy storage means includes means for damping the motion of the ramp.
Claim 4
Dependent Claim
17 words
The drive mechanism as set forth in claim 1 wherein said energy storage means includes a spring.
Claim 5
Dependent Claim
18 words
The drive mechanism as set forth in claim 1 wherein said energy storage means includes a pneumatic cylinder.
Claim 6
Dependent Claim
22 words
The drive mechanism as set forth in claim 1 wherein said motor is coupled to said gear through an electronically controlled clutch.
Claim 7
Dependent Claim
20 words
The drive mechanism as set forth in claim 5 wherein said clutch disengages when power to said clutch is interrupted.
Claim 8
Dependent Claim
68 words
A minivan adapted for wheelchair access by a ramp attached to the minivan, said minivan comprising: a motor coupled to the ramp for raising or lowering the ramp; and energy storage means coupled to the ramp for reducing the force needed to raise or lower the ramp, wherein said energy storage means operates independently of said motor to reduce the force needed to raise or lower said ramp.
Claim 9
Dependent Claim
68 words
A minivan adapted for wheelchair access by a ramp attached to the minivan, said minivan comprising: a motor coupled to the ramp for raising or lowering the ramp; and energy storage means coupled to the ramp for reducing the force needed to raise or lower the ramp, wherein said energy storage means operates independently of said motor to reduce the force needed to raise or lower said ramp.
Claim 10
Dependent Claim
116 words
A minivan adapted for wheelchair access by a ramp attached to the minivan, said minivan comprising: an electric motor mechanically coupled to the ramp for raising and lowering the ramp; and energy storage means mechanically coupled to the ramp for reducing the force needed to raise or lower the ramp; wherein said motor is coupled to said ramp by a gear driven lever arm and said energy storage means includes a spring coupled to said ramp by a cam attached to said lever arm and a plunger connecting said spring to said cam, wherein said spring applies a lifting force to said lever arm to oppose the force of gravity while raising or lowering said ramp.
Claim 11
Dependent Claim
116 words
A minivan adapted for wheelchair access by a ramp attached to the minivan, said minivan comprising: an electric motor mechanically coupled to the ramp for raising and lowering the ramp; and energy storage means mechanically coupled to the ramp for reducing the force needed to raise or lower the ramp; wherein said motor is coupled to said ramp by a gear driven lever arm and said energy storage means includes a spring coupled to said ramp by a cam attached to said lever arm and a plunger connecting said spring to said cam, wherein said spring applies a lifting force to said lever arm to oppose the force of gravity while raising or lowering said ramp.
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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) | 2002-02-15 | 2002-08-17 | 2003-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-15 | 2006-08-17 | 2007-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-15 | 2010-08-17 | 2011-02-16 | $7700.00 | Window Closed / Lapsed |