Patent US4000667A successfully refreshed from Google Patents.
US4000667A
Expired / Lapsed
US
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Bending bar constructed by bending
Assignee: Valenite LLC
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Filing: 1975-05-12
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Granted: 1977-01-04
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Expires: 1995-05-12
Abstract
Abstract A pair of boring bars are constructed from a single double length straight bar by providing a central bend of suitable angle and curvature to provide a pair of offset supports for a pair of cutting inserts having cutting points projecting to an offset cutting position relative to the periphery of the bar. Cutting out a small segment at the center of the bend provides two boring bars with curved ends. Machining of a chip clearance path and insert pocket on one side or the other of each bar completes a pair of left or a pair of right or opposite hand boring bars.
Inventors
- 👤 David Alan Hopkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:41
CPC Classifications
B; B23; B23P; B23P15/00; B23P15/28; B23P15/30; B23B; B23B27/00; B23B27/007; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49789; Y10T29/49792
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
80 words
The method for manufacturing a boring bar comprising the steps of bending a straight bar to provide an intermediate curved portion and an obtuse included angle relationship between the remaining straight portions, cutting the curved portion of said bar to provide a curved end portion on each of two straight portions, machining a chip clearance path and an insert pocket with an offset portion resulting from said bend providing a support surface for an offset cutting point of an insert.
Claim 2
Independent Claim
80 words
The method for manufacturing a boring bar comprising the steps of bending a straight bar to provide an intermediate curved portion and an obtuse included angle relationship between the remaining straight portions, cutting the curved portion of said bar to provide a curved end portion on each of two straight portions, machining a chip clearance path and an insert pocket with an offset portion resulting from said bend providing a support surface for an offset cutting point of an insert.
Claim 3
Dependent Claim
27 words
The method of claim 1 including the cutting of an end wall for said bent end extending substantially normal to the longitudinal center line of said bar.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein said bending step is a cold forming operation.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein said intermediate curved section extends through an arc in the order of 60°.
Claim 6
Dependent Claim
43 words
The method of claim 4 including the removal of a wedge having an included angle in the order of 60° from a central portion of said intermediate curved portion thereby providing end walls extending substantially normal to the longitudinal centerline of said bar.
Claim 7
Dependent Claim
21 words
The method of claim 1 wherein said intermediate curved section extends through an arc within the range of 45° to 75°.
Claim 8
Dependent Claim
29 words
The method of claim 1 applied to a round boring bar to provide a neutral axis bend radius within the range of 1.5 to 3.75 times the bar diameter.
Claim 9
Dependent Claim
27 words
The method of claim 1 applied to a round boring bar to provide a neutral axis bend radius in the order of 22/3 times the bar diameter.
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) | 1980-01-04 | 1980-07-05 | 1981-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-04 | 1984-07-05 | 1985-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-04 | 1988-07-05 | 1989-01-04 | $7700.00 | Window Closed / Lapsed |