Patent US3713501A successfully refreshed from Google Patents.
US3713501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power hand truck
Assignee: Individual
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Filing: 1970-11-06
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Granted: 1973-01-30
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Expires: 1990-11-06
Abstract
Abstract A hand truck frame mounts an endless chain belt having a perpendicularly extending bulb-like member connected thereto. As the belt rotates, the bulb-like member engages a step and causes the hand truck to be elevated to a vertically succeeding step. A manually operated clutch selectively links the chain belt with the wheel axle of the hand truck thereby powering the wheels, which is desirable on flat ground.
Inventors
- 👤 R Hurt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:28
CPC Classifications
B; B62; B62B; B62B5/00; B62B5/02; B62B5/023
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
107 words
A motorized load carrier adapted to climb stairs, the carrier comprising a frame, a transmission mechanism mounted on the frame, motor means for driving the transmission mechanism, and means connected to the transmission mechanism for engaging succeeding steps in a flight of steps to produce powered displacement of the carrier along the flight of steps, the step engaging means including longitudinal means mounted to the transmission mechanism and extending perpendicularly therefrom and parallel to a normal direction of movement of the carrier for rotation about an axis parallel to the normal direction of movement of the carrier for facilitating lateral movement of the carrier on the Step.
Claim 2
Dependent Claim
107 words
A motorized load carrier adapted to climb stairs, the carrier comprising a frame, a transmission mechanism mounted on the frame, motor means for driving the transmission mechanism, and means connected to the transmission mechanism for engaging succeeding steps in a flight of steps to produce powered displacement of the carrier along the flight of steps, the step engaging means including longitudinal means mounted to the transmission mechanism and extending perpendicularly therefrom and parallel to a normal direction of movement of the carrier for rotation about an axis parallel to the normal direction of movement of the carrier for facilitating lateral movement of the carrier on the Step.
Claim 3
Dependent Claim
107 words
A motorized load carrier adapted to climb stairs, the carrier comprising a frame, a transmission mechanism mounted on the frame, motor means for driving the transmission mechanism, and means connected to the transmission mechanism for engaging succeeding steps in a flight of steps to produce powered displacement of the carrier along the flight of steps, the step engaging means including longitudinal means mounted to the transmission mechanism and extending perpendicularly therefrom and parallel to a normal direction of movement of the carrier for rotation about an axis parallel to the normal direction of movement of the carrier for facilitating lateral movement of the carrier on the Step.
Claim 4
Dependent Claim
107 words
A motorized load carrier adapted to climb stairs, the carrier comprising a frame, a transmission mechanism mounted on the frame, motor means for driving the transmission mechanism, and means connected to the transmission mechanism for engaging succeeding steps in a flight of steps to produce powered displacement of the carrier along the flight of steps, the step engaging means including longitudinal means mounted to the transmission mechanism and extending perpendicularly therefrom and parallel to a normal direction of movement of the carrier for rotation about an axis parallel to the normal direction of movement of the carrier for facilitating lateral movement of the carrier on the Step.
Claim 5
Dependent Claim
46 words
The structure of claim 1, further including a wheel assembly and wherein said transmission mechanism includes an endless belt having the longitudinal means mounted thereto and being connected directly to the wheel assembly, and the transmission mechanism further includes a chain drive for driving the belt.
Claim 6
Dependent Claim
19 words
The structure of claim 2 wherein the motor means comprises an electric drill motor coupled to the gear means.
Claim 7
Dependent Claim
44 words
The structure of claim 1, further including a wheel assembly, and wherein said transmission mechanism includes an endless belt having the longitudinal means mounted thereto and connected to the wheel assembly, and the motor means comprises an electric motor permanently mounted to the frame.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |