US3591306A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Core borer
Assignee: BBC Brown Boveri AG Germany
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Filing: 1969-01-02
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Granted: 1971-07-06
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Expires: 1989-01-02
Abstract
Abstract A core drill structure comprises a hollow shaft to which an annular drill head is secured, the drill head including a plurality of equispaced recesses for receiving plates provided with alternatively usable cutting edges for drilling an annular hole. The cutting edges of the plates are respectively staggered in a radial direction so that each cutting edge works only a portion of the width of the annular cut, and these cutting edges are also disposed respectively in different planes normal to the drill axis in order to also establish an axial staggering of the cutting edges of adjacent plates.
Inventors
- 👤 Alfred Kaser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:23
CPC Classifications
B; B23; B23B; B23B51/00; B23B51/04; B23B51/0466; Y; Y10; Y10T; Y10T408/00; Y10T408/44; Y10T408/45; Y10T408/455; Y10T408/89; Y10T408/895
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
197 words
In a core drill the combination comprising a hollow shafT, an annular drill head secured to the lower end of said drill shaft, means providing a plurality of circumferentially and equally spaced recesses in the body of said drill head extending to the bottom thereof, and a cutter plate individual to and secured in each said recess in a plane substantially radial to the drill axis, each said cutter plate being provided with alternatively usable hard cutting edges along different sides thereof, the cutting edge extending for only a portion of the appertaining side and being offset from the remaining noncutting portion so as to project in an axial direction beyond the cutter edge, the inuse cutting edge of each said plate being staggered in a radial direction in relation to the in-use cutting edge of an adjacent plate such that the cutting edge of each said plate machines only a portion of the width of the annular hole which is drilled, and the in-use cutting edges of adjacent plates being disposed respectively in different planes which are normal to the drill axis such as to establish an axial staggering of the cutting edges of adjacent plates.
Claim 2
Dependent Claim
197 words
In a core drill the combination comprising a hollow shafT, an annular drill head secured to the lower end of said drill shaft, means providing a plurality of circumferentially and equally spaced recesses in the body of said drill head extending to the bottom thereof, and a cutter plate individual to and secured in each said recess in a plane substantially radial to the drill axis, each said cutter plate being provided with alternatively usable hard cutting edges along different sides thereof, the cutting edge extending for only a portion of the appertaining side and being offset from the remaining noncutting portion so as to project in an axial direction beyond the cutter edge, the inuse cutting edge of each said plate being staggered in a radial direction in relation to the in-use cutting edge of an adjacent plate such that the cutting edge of each said plate machines only a portion of the width of the annular hole which is drilled, and the in-use cutting edges of adjacent plates being disposed respectively in different planes which are normal to the drill axis such as to establish an axial staggering of the cutting edges of adjacent plates.
Claim 3
Dependent Claim
30 words
A core drill as defined in claim 1 and wherein said cutter plates are provided with lateral guiding surfaces which are slidable along the wall of the annular drilled hole.
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) | 1974-07-05 | 1975-01-04 | 1975-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-05 | 1979-01-04 | 1979-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-05 | 1983-01-04 | 1983-07-06 | $7700.00 | Window Closed / Lapsed |