US3887978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacturing of bevel gear by cold forming of blanks in a press die
Assignee: KM Kabelmetal AG
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Filing: 1974-04-08
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Granted: 1975-06-10
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Expires: 1994-04-08
Abstract
Abstract Bevel gear is made by cold forming of a cylindrical blank in a die, using a press punch and a counter punch, and wherein the die cavity is extended cylindrically with gear like cross-section corresponding to the smallest gear diameter portion of the bevel gear. The counter punch is initially in a receded disposition so that some material of the blank is extruded into the tooth impressions of the die cavity extension. The die is resiliently supported in relation to the counter punch so that in the last phases of press forming, the counter punch pushes the material from the cavity extension into the cavity proper for completely filling the tooth impressions in the die wherein the small diameter portion of the bevel gear is formed.
Inventors
- 👤 Fritz Dohmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:53
CPC Classifications
B; B21; B21K; B21K1/00; B21K1/28; B21K1/30; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49462; Y10T29/49467; Y10T29/49474
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
103 words
In an apparatus for forming bevel gear, including a die with bevel gear forming die cavity, a punch acting from the side of largest diameter of the die cavity and a counter punch acting from the side of smallest diameter, the improvement, comprising: a continuation portion of the die cavity having gear shaped cross-sectional contour corresponding to the smallest, bevelgear-defining cavity portion, and having longitudinally cylindrical configuration; the counter punch positioned in said continuation portion of the die cavity and having correspondingly gear like cross-section; and means for advancing the counter punch during the last phase of the relative advance of the punch.
Claim 2
Dependent Claim
103 words
In an apparatus for forming bevel gear, including a die with bevel gear forming die cavity, a punch acting from the side of largest diameter of the die cavity and a counter punch acting from the side of smallest diameter, the improvement, comprising: a continuation portion of the die cavity having gear shaped cross-sectional contour corresponding to the smallest, bevelgear-defining cavity portion, and having longitudinally cylindrical configuration; the counter punch positioned in said continuation portion of the die cavity and having correspondingly gear like cross-section; and means for advancing the counter punch during the last phase of the relative advance of the punch.
Claim 3
Dependent Claim
57 words
In an apparatus as in claim 1, including means for resiliently supporting the die with respect to the counter punch, to obtain counter punch movement towards the die cavity during the last phase of forming, when the press force as transmitted by the punch viA blank onto the die overcomes resilient resistance by the means for supporting.
Claim 4
Dependent Claim
28 words
In an apparatus as in claim 2 wherein the front end of the counter punch is held in receded disposition from the die cavity prior to press forming.
Claim 5
Independent Claim
173 words
The method of forming bevel gear by means of a die with bevel gear forming die cavity, punch and counter punch, comprising the steps of using a die with a cavity continuation at the end of smallest bevel gear diameter and axially continuing the dimensions thereof. using a counter punch with gear shaped outer contour for slidable displacement in the cavity continuation and establishing a temporary bottom for the die cavity; positioning the counter punch in receded disposition relative to the bevel gear defining die cavity; placing a cylindrical blank into the cavity so that it rests on the counter punch; forcing the punch against the blank for causing the blank to deform and flow radially outwardly to fill the contour of the die cavity; and causing the counter punch to advance toward the punch during the last phases of bevel gear forming by forcing material from the blank which flowed radially from the blank where resting on the counter punch, into the teeth defining cavities of smallest diameter for filling same completely.
Claim 6
Independent Claim
173 words
The method of forming bevel gear by means of a die with bevel gear forming die cavity, punch and counter punch, comprising the steps of using a die with a cavity continuation at the end of smallest bevel gear diameter and axially continuing the dimensions thereof. using a counter punch with gear shaped outer contour for slidable displacement in the cavity continuation and establishing a temporary bottom for the die cavity; positioning the counter punch in receded disposition relative to the bevel gear defining die cavity; placing a cylindrical blank into the cavity so that it rests on the counter punch; forcing the punch against the blank for causing the blank to deform and flow radially outwardly to fill the contour of the die cavity; and causing the counter punch to advance toward the punch during the last phases of bevel gear forming by forcing material from the blank which flowed radially from the blank where resting on the counter punch, into the teeth defining cavities of smallest diameter for filling same completely.
Claim 7
Dependent Claim
67 words
In the method as in claim 4, wherein the counter punch has disposition below the plane in the die cavity defining the small diameter end of the bevel gear to be made so that the material flowing into the grooves of the die cavity extensions when forced and displaced axially upon advance of the counter punch will fill the tooth defining portions of the die cavity completely.
Claim 8
Dependent Claim
47 words
The method as in claim 4, wherein the support for the counter punch bears resiliently against die, the resiliency being overcome during advance of the punch as forcing the blank into peripheral grooves of the die to thereby causing the counter punch to advance toward the punch.
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) | 1978-06-09 | 1978-12-09 | 1979-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-09 | 1982-12-09 | 1983-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-09 | 1986-12-09 | 1987-06-10 | $7700.00 | Window Closed / Lapsed |