US3722863A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lift apparatus
Assignee: IHI Corp
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Filing: 1971-12-22
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Granted: 1973-03-27
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Expires: 1991-12-22
Abstract
Abstract When a plurality of hydraulic cylinders are actuated for lifting or lowering a platform, the platform and the load applied to it are supported by a plurality of locking plates coupled to the cylinders and each having a plurality of trapezoidal teeth in engagement with the similar teeth of a rack attached to a post along which the platform is lifted or lowered. Lever means are provided for locking in position the platform for a long time even when the hydraulic pressure is not applied to the locking cylinders which cause said locking plates to engage with the racks.
Inventors
- 👤 I Itoh
- 👤 F Nakazono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:20
CPC Classifications
E; E02; E02B; E02B17/00; E02B17/04; E02B17/08; E02B17/0809; E02B17/0836; E02B17/0872
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
292 words
A lift apparatus comprising a post; a platform fitted over said post for slidable vertical movement; a plurality of racks each of which has trapezoidal teeth and a pair of guides extended on both sides of said rack in the longitudinal direction thereof, and which is attached to the outer surface of said post in the axial direction thereof; a plurality of lift devices disposed below said platform for lifting or lowering said platform, each of said plurality of lift devices comprising a box formed with a pair of guide shoes slidably fitted over said guides respectively, a lock plate which has a plurality of trapezoidal teeth adapted for engagement with said trapezoidal teeth of said rack and which is slidably fitted into said box, a pair of lock cylinders operatively coupled to said box and said lock plate so as to cause said lock plate to engage with or disengage from said rack, and a plurality of lift cylinders operatively coupled to said platform and to said locK plate in said box; and a plurality of locking devices disposed above said platform for supporting and locking in position said platform, each of said plurality of locking devices comprising a box formed with a pair of guide shoes slidably fitted over said guides of said rack respectively, a lock plate which has a plurality of trapezoidal teeth adapted for engagement with said trapezoidal teeth of said rack and which is slidably fitted into said box, a pair of lock cylinders operatively coupled to said box and said lock plate so as to cause said lock plate to engage with or disengage from said rack, and a rocking lever interconnecting said lock plate in said box with the top surface of said platform.
Claim 2
Dependent Claim
292 words
A lift apparatus comprising a post; a platform fitted over said post for slidable vertical movement; a plurality of racks each of which has trapezoidal teeth and a pair of guides extended on both sides of said rack in the longitudinal direction thereof, and which is attached to the outer surface of said post in the axial direction thereof; a plurality of lift devices disposed below said platform for lifting or lowering said platform, each of said plurality of lift devices comprising a box formed with a pair of guide shoes slidably fitted over said guides respectively, a lock plate which has a plurality of trapezoidal teeth adapted for engagement with said trapezoidal teeth of said rack and which is slidably fitted into said box, a pair of lock cylinders operatively coupled to said box and said lock plate so as to cause said lock plate to engage with or disengage from said rack, and a plurality of lift cylinders operatively coupled to said platform and to said locK plate in said box; and a plurality of locking devices disposed above said platform for supporting and locking in position said platform, each of said plurality of locking devices comprising a box formed with a pair of guide shoes slidably fitted over said guides of said rack respectively, a lock plate which has a plurality of trapezoidal teeth adapted for engagement with said trapezoidal teeth of said rack and which is slidably fitted into said box, a pair of lock cylinders operatively coupled to said box and said lock plate so as to cause said lock plate to engage with or disengage from said rack, and a rocking lever interconnecting said lock plate in said box with the top surface of said platform.
Claim 3
Dependent Claim
43 words
A lift apparatus as set forth in claim 1 wherein the locking cylinders in said plurality of locking devices disposed above said platform and in said plurality of lift devices disposed below said platform are alternately actuated to lift or lower said platform.
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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |