Lifting mechanisms
Abstract
Abstract A LIFTING MECHANISM INCORPORATING A POSITIVE BRAKE MEANS TO PREVENT UNCONTROLLED DESCENT OF THE LOAD WHEN THE LIFTING DRIVE IS DISCONTINUED. THE MECHANISM INCLUDES A GEAR WHEEL CONNECTED TO A ROTARY DRIVE MEANS AND MESHING WITH A SECOND GEAR WHEEL CONNECTED TO A ROTARY HOIST MEMBER, AND A LOCKING MEMBER ROTATABLY MOUNTED COAXIALLY WITH THE FIRST MENTIONED GEAR WHEEL AND HAVING A SPRAGGING GEAR PERMANENTLY IN MESH WITH THE FIRST MENTIONED GEAR WHEEL AND MOVABLE WITH THE ROTARY MOVEMENT OF THE FIRST MENTIONED GEAR WEEL BETWEEN A LOCKING POSITION WHEN THE SPRAGGING GEAR IS IN MESH WITH THE SECOND GEAR WHEEL AND A FURTHER POSITION IN WHICH THE SPRAGGING GEAR IS OUT OF MESH WITH THE SECOND GEAR WHEEL, MOVEMENT BETWEEN THE FIRST AND SECOND POSITIONS TAKING PLACE WHEN THE HOIST IS CAUSED TO RISE AND MOVEMENT IN THE REVERSE DIRECTION TAKING PLACE WHEN THE HOISE COMMENCES TO LOWER. CATCH WHEELS ARE PROVIDED TO MAINTAIN THE LOCKING MEMBER IN ITS SECOND POSITION TO ALLOW UNCONTROLLED LOWERING OF THE HOIST THROUGH THE ROTARY DRIVE MEANS. THE DRIVE MEANS MAY BE HAND OPERATED.
Inventors
- 👤 John Edward Metcalf
Bibliographic Details
Claims Analysis
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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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |