US4005665A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making press-working blanks with reduced ear occurrence
Assignee: Nippon Steel Corp
•
Filing: 1975-05-07
•
Granted: 1977-02-01
•
Expires: 1995-05-07
Abstract
Abstract A method for preparing a steel blank which is less susceptible to ear occurrence during its press-working into a pressed article, which comprising cutting a cold rolled steel sheet in a planar shape obtained by overlapping a circle having a diameter R and a square having a side length of about 13/14 R with their center points being at the same point and cutting the unoverlapped portions to form a blank with a periphery having alternating arcuate and straight edges. A blank is thus provided having less material due to the straight edges in those areas where large ears would otherwise occur during working.
Inventors
- 👤 Toshiro Nishihara
- 👤 Nobuyuki Takahashi
- 👤 Hiroshi Katoh
- 👤 Touru Ishimaru
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:07
CPC Classifications
B; B21; B21D; B21D28/00; B21D28/02; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12229; Y10T428/12236; Y10T428/12243; Y10T83/00; Y10T83/04; Y10T83/0524; Y10T83/0529
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
52 words
A method for preparing a steel blank which comprises cutting a cold rolled steel sheet in a planar shape obtained by overlapping a circle having a diameter R and a square having a side length of about 13/14 with their center points being at the same point and by cutting unoverlapped portions.
Claim 2
Independent Claim
52 words
A method for preparing a steel blank which comprises cutting a cold rolled steel sheet in a planar shape obtained by overlapping a circle having a diameter R and a square having a side length of about 13/14 with their center points being at the same point and by cutting unoverlapped portions.
Claim 3
Dependent Claim
18 words
The method according to claim 2, in which the cold rolled steel sheet is in an annealed condition.
References Cited (Backward Citations)
US3490124A
Cited
US3664890A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-01 | 1980-08-02 | 1981-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-01 | 1984-08-02 | 1985-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-01 | 1988-08-02 | 1989-02-01 | $7700.00 | Window Closed / Lapsed |