US3595094A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rack and worm mechanism
Assignee: SKF AB
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Filing: 1969-06-27
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Granted: 1971-07-27
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Expires: 1989-06-27
Abstract
Abstract Device for transforming a movement of rotation into a movement of translation by means of a high-efficiency rack and worm mechanism characterized in that the rack teeth formed on one portion of a cylinder consist of a multithread tapping of a solid member, in that the worm coaxial with said rack has a number of threads generally equal to that of said rack, and that a plurality of externally screw-threaded planet rollers are disposed around said worm and mesh both with said worm and said rack, the helix angle of the threads formed on said planet rollers threads being the same as that of the worm threads and of opposite direction whereby the planet rollers rolling without slip on the worm are held against any axial movement in relation to said worm.
Inventors
- 👤 Pierre Lemor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:11
CPC Classifications
F; F16; F16H; F16H25/00; F16H25/18; F16H25/20; F16H25/22; F16H25/2247; F16H25/2252; Y; Y10; Y10T; Y10T74/00; Y10T74/18; Y10T74/18568; Y10T74/18792; Y10T74/19; Y10T74/19642; Y10T74/19698; Y10T74/19702; Y10T74/19744; Y10T74/19781; Y10T74/19791; Y10T74/19795
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
249 words
A device adapted to be mounted on a frame structure for transforming a movement of rotation into a movement of translation, comprising a main rack consisting of a partcylindrical surface formed with a plurality of internal threads, a worm coaxial to said rack and having a plurality of external threads, externally screw-threaded planet rollers disposed about said worm and simultaneously engaging the threads of said worm and said main rack, said main rack and worm adapted for relative longitudinal movement upon rotation of said worm, the helix angle of the threads formed on said planEt rollers being identical with that of the worm threads and of the opposite direction, whereby said planet rollers, by rolling without slipping on said worm, are prevented from moving longitudinally in relation thereto, and an auxiliary rack consisting of a part-cylindrical surface formed with a plurality of threads having a predetermined pitch, the length of said auxiliary tack being substantially identical with that of said worm, whereby said screw-threaded planet rollers can roll, during the lower portion of their path, on said auxiliary rack, the pitch of the multithread tapping of said auxiliary rack being predetermined so that the pitch of the assembly comprising said worm, said auxiliary rack and said screw-threaded planet rollers is zero whereby longitudinal movement of the auxiliary rack is zero in relation to said worm so that the auxiliary rack serves as a stop to transmit to the frame structure load applied by said main rack to said worm.
Claim 2
Independent Claim
249 words
A device adapted to be mounted on a frame structure for transforming a movement of rotation into a movement of translation, comprising a main rack consisting of a partcylindrical surface formed with a plurality of internal threads, a worm coaxial to said rack and having a plurality of external threads, externally screw-threaded planet rollers disposed about said worm and simultaneously engaging the threads of said worm and said main rack, said main rack and worm adapted for relative longitudinal movement upon rotation of said worm, the helix angle of the threads formed on said planEt rollers being identical with that of the worm threads and of the opposite direction, whereby said planet rollers, by rolling without slipping on said worm, are prevented from moving longitudinally in relation thereto, and an auxiliary rack consisting of a part-cylindrical surface formed with a plurality of threads having a predetermined pitch, the length of said auxiliary tack being substantially identical with that of said worm, whereby said screw-threaded planet rollers can roll, during the lower portion of their path, on said auxiliary rack, the pitch of the multithread tapping of said auxiliary rack being predetermined so that the pitch of the assembly comprising said worm, said auxiliary rack and said screw-threaded planet rollers is zero whereby longitudinal movement of the auxiliary rack is zero in relation to said worm so that the auxiliary rack serves as a stop to transmit to the frame structure load applied by said main rack to said worm.
Claim 3
Dependent Claim
52 words
A device as set forth in claim 1, which comprises a pair of annular flanges and holes formed through said flanges, in which the trunnion-forming ends of said screw-threaded planet rollers are adapted to be journaled, whereby both flanges constitute a cage holding said screw-threaded planet rollers in position about said worm.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |