Patent US5014823A successfully refreshed from Google Patents.
US5014823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for improving the performance of a motor-controlled hydraulic elevator
Assignee: Kone Elevator GmbH
•
Filing: 1989-08-29
•
Granted: 1991-05-14
•
Expires: 2009-08-29
Abstract
Abstract The invention concerns an apparatus for improving the performance of a motor-controlled hydraulic elevator, in which oil is pumped using an hydraulic pump controlled by an electric motor from a container via a main supply duct into a lifting cylinder to move the elevator upwards, and returned in a controlled manner through the pump into the container to move the elevator downwards. In order to improve the loading conditions of the motor during down-travel, the oil pressure in the main duct is reduced to a substantially predetermined constant level by means of a check valve or lowering valve which, to provide compensation for the pressure in the pump, has a feedback connection to the main duct via a pressure compensation valve which controls the volume of flow through the check valve or lowering valve.
Inventors
- 👤 Raimo Pelto-Huikko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:16
CPC Classifications
F; F15; F15B; F15B21/00; F15B21/14; B; B66; B66B; B66B1/00; B66B1/24; B66B9/00; B66B9/04
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
147 words
An apparatus for improving the performance of a motor-controlled hydraulic elevator, which apparatus comprises a hydraulic pump connected to an electric motor, an oil container, a main duct leading from the container to the pump and further to a lifting cylinder of the elevator, and a braking device which derives oil from the lifting cylinder through the hydraulic pump by way of the main duct during downward drive, the braking device includes a means for reducing oil pressure in the main duct and which utilizes a check valve, connecting the lifting cylinder and the main duct, and a pressure compensation valve connected to the check valve, the pressure compensation valve senses the pressure in the main duct and provides a means to control the flow of oil through the check valve so as to maintain the pressure in the hydraulic pump at a substantially constant predetermined level.
Claim 2
Independent Claim
147 words
An apparatus for improving the performance of a motor-controlled hydraulic elevator, which apparatus comprises a hydraulic pump connected to an electric motor, an oil container, a main duct leading from the container to the pump and further to a lifting cylinder of the elevator, and a braking device which derives oil from the lifting cylinder through the hydraulic pump by way of the main duct during downward drive, the braking device includes a means for reducing oil pressure in the main duct and which utilizes a check valve, connecting the lifting cylinder and the main duct, and a pressure compensation valve connected to the check valve, the pressure compensation valve senses the pressure in the main duct and provides a means to control the flow of oil through the check valve so as to maintain the pressure in the hydraulic pump at a substantially constant predetermined level.
Claim 3
Dependent Claim
32 words
An apparatus according to claim 1, wherein a separate magnetic valve for controlling the opening and closing of the check valve is connected between the check valve and the pressure compensation valve.
Claim 4
Dependent Claim
34 words
An apparatus according to claim 1, wherein the elevator car is provided with a counterweight of a size that compensates a major proportion but not all of the weight of the car when empty.
Claim 5
Dependent Claim
34 words
An apparatus according to claim 1, wherein the elevator car is provided with a counterweight of a size that compensates between 70 percent and 80 percent of the weight of the car when empty.
References Cited (Backward Citations)
JPS5130335A
Cited
JPS5418568A
Cited
US4179889A
Cited
US4676140A
Cited
US4637495A
Cited
DE3629032A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-13 | 1994-11-12 | 1995-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-13 | 1998-11-12 | 1999-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-13 | 2002-11-12 | 2003-05-14 | $7700.00 | Window Closed / Lapsed |