Patent US3813909A successfully refreshed from Google Patents.
US3813909A
Expired / Lapsed
US
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Methods of extruding helical gear blanks
Assignee: Peugeot & Renault
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Filing: 1971-11-18
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Granted: 1974-06-04
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Expires: 1991-11-18
Abstract
Abstract Method of manufacturing helical gear blanks by cold extrusion, characterized in that it comprises the steps of passing successive billets through a die formed with internal helical teeth in order to impress these internal helical teeth by extrusion in the billet for forming external helical teeth in the cylindrical surface of said billets, said billets being driven through said die by a punch adapted to rotate freely.
Inventors
- 👤 Y Roger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:58
CPC Classifications
B; B21; B21K; B21K1/00; B21K1/28; B21K1/30; B21K1/305; B21C; B21C25/00; B21C25/10; B21K5/00; B21K5/20; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49462; Y10T29/49467; Y10T29/49474
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
88 words
Method of manufacturing helical gear blanks by cold extrusion, characterized in that it comprises the steps of passing successive billets through a die formed with internal helical teeth in order to impress these internal helical teeth by extrusion in the billet for forming external helical teeth in the cylindrical surface of said billets, said billets being driven through said die by a punch adapted to rotate freely and said die composed of at least two sleeve-shaped die blank elements disposed in stacked relationship and locked against relative rotation.
Claim 2
Dependent Claim
88 words
Method of manufacturing helical gear blanks by cold extrusion, characterized in that it comprises the steps of passing successive billets through a die formed with internal helical teeth in order to impress these internal helical teeth by extrusion in the billet for forming external helical teeth in the cylindrical surface of said billets, said billets being driven through said die by a punch adapted to rotate freely and said die composed of at least two sleeve-shaped die blank elements disposed in stacked relationship and locked against relative rotation.
Claim 3
Dependent Claim
31 words
Method according to claim 1, characterized in that each billet is pushed through the die through the medium of the next billet previously interposed between the first billet and the punch.
Claim 4
Dependent Claim
46 words
Method according to claim 1, characterized in that a downward operating stroke of said punch determines on the one hand the completion of the extrusion operation and the ejection of a billet, and on the other hand the beginning of the extrusion of the next billet.
Claim 5
Dependent Claim
20 words
Method according to claim 1, characterized in that the punch pressure is exerted throughout the cross-sectional area of the billet.
Claim 6
Dependent Claim
38 words
Method according to claim 1, characterized in that the extrusion pressure is transmitted to the punch through a roller thrust bearing in order to permit the free rotation of said punch and also of the billets being extruded.
Claim 7
Dependent Claim
52 words
Method according to claim 1, characterized in that the helix angle is constantly checked by measuring the angular magnitude of the punch rotation and of its bearing member in relation to its downward movement, from a given pressure corresponding to the billet engagement pressure, the press operation being responsive to said measurement.
Claim 8
Dependent Claim
56 words
Method according to claim 1, characterized in that, from the very beginning of the billet engagement, said inner helical teeth of said die impress the tips of the teeth in said billet and then gradually the complete clearances of said teeth by continuously increasing the height of the die teeth, their width and outline remaining constant.
Claim 9
Dependent Claim
60 words
Method according to claim 7, characterized in that the inner helical teeth of said die have the surface area of its tooth clearances corresponding to thE envelope cylinder of the gear to be formed, and the surface area of the tooth tips in the extrusion areas correspond to successive frustoconical extrusion surfaces separated by clearances and coaxial to said cylinder.
Claim 10
Dependent Claim
57 words
Method according to claim 7, characterized in that the major base of the extrusion input frustoconical surface corresponds to the diameter of the envelope cylinder of the gear at the input end of the die, the minor base of the last extrusion frustoconical surface, at the die output end, corresponding to the root circle of the gear.
Claim 11
Dependent Claim
29 words
Method according to claim 8, characterized in that the taper of the developed helical generatrix of the tooth tips in the frustoconical extrusion surface ranges from 10* to 20*.
Claim 12
Dependent Claim
54 words
Method of manufacturing helical gear blanks according to claim 9, characterized in that each die element comprises a frustoconical extrusion surface connected through a so-called neck portion to a reverse cone provided for releasing the billet, the input diameter of the extrusion cone being slightly greater than the neck diameter of the preceding element.
Claim 13
Dependent Claim
30 words
Method according to claim 11, characterized in that the height of the billet release cone is slightly greater than the height of said billet during its passage through said portion.
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) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |