US4716976A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary percussion drill bit
Assignee: Kennametal PC Inc
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Filing: 1986-10-28
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Granted: 1988-01-05
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Expires: 2006-10-28
Abstract
Abstract A rotary percussion rock drill bit has a body and a symmetrical cross-like arrangement of crushing and cutting inserts secured on the body. The bit body has a rearward shank portion and a forward boring head portion with a front face. The cylindrical crushing inserts are secured in the forward head portion and have noncutting hemispherical rock crushing ends exposed at the front face of the head portion. The cutting inserts, which can be rectangular or cylindrical in shape, are secured in the forward head portion and have roof-shaped ends exposed at the front face of the head portion. A peak of each roof-shaped end defines a rock cutting edge. The crushing and cutting inserts are arranged on the head portion with their respective hemispherical and roof-shaped ends in a symmetrical cross-like pattern. The bit body also has a longitudinal central axis, and the crushing and cutting inserts are aligned along planes disposed in orthogonal relation to one another and intersecting at the central axis. At least one crushing insert is disposed on each opposite side of the central axis along one of the planes, whereas at least one cutting insert is disposed on each opposite side of the central axis along the other of the planes. The cutting edge of each of the cutting inserts extends generally parallel to and offset from the plane along which the cutting inserts are aligned.
Inventors
- 👤 Edmund Isakov
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:12
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46; E21B10/58; E21B10/36; E21B10/38; E21B10/56
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
164 words
In a rock drill bit, the combination comprising: (a) a body having a rearward shank portion, a forward boring head with a front face and a longitudinal central axis; (b) a plurality of cylindrical crushing inserts secured in said forward boring head portion and having noncutting rock crushing hemispherical shaped ends exposed at said front face thereof; and (c) a plurality of cutting inserts secured in said forward head portion and having roof-shaped ends exposed at said front face thereof with a peak of each said roof-shaped ends defining a rock cutting edge; (d) said crushing and cutting inserts being arranged on said head portion with their respective hemispherical and roof-shaped ends in a symmetrical cross-like pattern; (e) wherein said crushing and cutting inserts are aligned along planes disposed in orthogonal relation to one another and intersecting at said central axis; (f) and wherein at least two crushing inserts are disposed on each opposite side of said central axis along one of said planes.
Claim 2
Dependent Claim
164 words
In a rock drill bit, the combination comprising: (a) a body having a rearward shank portion, a forward boring head with a front face and a longitudinal central axis; (b) a plurality of cylindrical crushing inserts secured in said forward boring head portion and having noncutting rock crushing hemispherical shaped ends exposed at said front face thereof; and (c) a plurality of cutting inserts secured in said forward head portion and having roof-shaped ends exposed at said front face thereof with a peak of each said roof-shaped ends defining a rock cutting edge; (d) said crushing and cutting inserts being arranged on said head portion with their respective hemispherical and roof-shaped ends in a symmetrical cross-like pattern; (e) wherein said crushing and cutting inserts are aligned along planes disposed in orthogonal relation to one another and intersecting at said central axis; (f) and wherein at least two crushing inserts are disposed on each opposite side of said central axis along one of said planes.
Claim 3
Dependent Claim
30 words
The drill bit as defined in claim 1, wherein at least one cutting insert is disposed on each opposite side of said central axis along the other of said planes.
Claim 4
Dependent Claim
21 words
The drill bit as defined in claim 1, wherein an axis of each cylindrical crushing insert lies in said one plane.
Claim 5
Dependent Claim
30 words
The drill bit as defined in claim 1, wherein at least two cutting inserts are disposed on each opposite side of said central axis along the other of said planes.
Claim 6
Dependent Claim
170 words
In a rock drill bit, the combination comprising: (a) a body having a rearward shank portion, a forward boring head with a front face and a longitudinal central axis; (b) a plurality of cylindrical crushing inserts secured in said forward boring head portion and having noncutting rock crushing hemispherical shaped ends exposed at said front face thereof; and (c) a plurality of cutting inserts secured in said forward head portion and having roof-shaped ends exposed at said front face thereof with a peak of each said roof-shaped ends defining a rock cutting edge; (d) said crushing and cutting inserts being arranged on said head portion with their respective hemispherical and roof-shaped ends in a symmetrical cross-like pattern; (e) wherein said crushing and cutting inserts are aligned along planes disposed in orthogonal relation to one another and intersecting at said central axis; (f) and wherein said cutting edge of each of said cutting inserts extends generally parallel to and offset from said plane along which said each cutting insert is aligned.
Claim 7
Dependent Claim
170 words
In a rock drill bit, the combination comprising: (a) a body having a rearward shank portion, a forward boring head with a front face and a longitudinal central axis; (b) a plurality of cylindrical crushing inserts secured in said forward boring head portion and having noncutting rock crushing hemispherical shaped ends exposed at said front face thereof; and (c) a plurality of cutting inserts secured in said forward head portion and having roof-shaped ends exposed at said front face thereof with a peak of each said roof-shaped ends defining a rock cutting edge; (d) said crushing and cutting inserts being arranged on said head portion with their respective hemispherical and roof-shaped ends in a symmetrical cross-like pattern; (e) wherein said crushing and cutting inserts are aligned along planes disposed in orthogonal relation to one another and intersecting at said central axis; (f) and wherein said cutting edge of each of said cutting inserts extends generally parallel to and offset from said plane along which said each cutting insert is aligned.
Claim 8
Dependent Claim
17 words
The drill bit as defined in claim 5, wherein said cutting inserts are generally rectangular in shape.
Claim 9
Dependent Claim
17 words
The drill bit as defined in claim 5, wherein said cutting inserts are generally cylindrical in shape.
Claim 10
Dependent Claim
73 words
The drill bit as defined in claim 5, wherein at least one cutting insert is disposed on each opposite side of said central axis, said cutting edge of said cutting insert on one opposite side of said central axis being offset from said plane in an opposite direction from that in which said cutting edge of said cutting insert on the other opposite side of said central axis is offset from said plane.
Claim 11
Dependent Claim
17 words
The drill bit as defined in claim 8, wherein said cutting inserts are generally rectangular in shape.
Claim 12
Dependent Claim
17 words
The drill bit as defined in claim 8, wherein said cutting inserts are generally cylindrical in shape.
References Cited (Backward Citations)
US1098795A
Cited
US1483296A
Cited
US2689109A
Cited
US2776819A
Cited
US2815932A
Cited
US3269469A
Cited
US3294186A
Cited
US3519092A
Cited
US3618683A
Cited
US4026372A
Cited
US4181187A
Cited
US4294319A
Cited
US4527641A
Cited
US4397361A
Cited
US4572307A
Cited
US4598779A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |