US3749189A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rock drilling bit
Assignee: WERKZEUGBAU GmbH
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Filing: 1971-03-01
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Granted: 1973-07-31
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Expires: 1991-03-01
Abstract
Abstract The present rock drilling bit has either one or two worms or screws extending helically around its shaft. Each worm is formed by a bottom surface and by substantially laterally extending flanks in such a manner that each bottom surface extends in parallel to the longitudinal axis of the shaft of the drill bit. The lateral flanks are inclined relative to said bottom surface substantially in the same manner, whereby the flank which is closer to the tip of the drill bit forms an acute angle relative to said bottom surface.
Inventors
- 👤 O Boehm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:00
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/44; E21B10/445; Y; Y10; Y10T; Y10T408/00; Y10T408/89; Y10T408/909; Y10T408/9095; Y10T408/9097
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
194 words
In a rock drilling bit having a shaft with a longitudinal axis and a given outer diameter, a tip at one end of the shaft and a shank at the other end of the shaft, as well as worm means extending around the shaft between the tip and the shank for removing drilling chips, each worm means comprising a bottom surface and two lateral flanks, said bottom surface extending in parallel to said longitudinal axis relative to any arbitrary axial section through the shaft, the improvement comprising a first angle ( Alpha ) of about 4* to 7* included between any of said lateral flanks closer to said tip (11) and a first plane extending perpendicularly to said longitudinal axis, a second angle ( Beta ) of about 15* to 20* included between the respective opposite flank closer to the shank (12) and a further plane extending in parallel to said first plane, all of said lateral flanks having a slope which points toward said tip, whereby an acute angle ( gamma , gamma '') facing toward said tip is included between the slope of any one of said flanks and said longitudinal axis.
Claim 2
Dependent Claim
194 words
In a rock drilling bit having a shaft with a longitudinal axis and a given outer diameter, a tip at one end of the shaft and a shank at the other end of the shaft, as well as worm means extending around the shaft between the tip and the shank for removing drilling chips, each worm means comprising a bottom surface and two lateral flanks, said bottom surface extending in parallel to said longitudinal axis relative to any arbitrary axial section through the shaft, the improvement comprising a first angle ( Alpha ) of about 4* to 7* included between any of said lateral flanks closer to said tip (11) and a first plane extending perpendicularly to said longitudinal axis, a second angle ( Beta ) of about 15* to 20* included between the respective opposite flank closer to the shank (12) and a further plane extending in parallel to said first plane, all of said lateral flanks having a slope which points toward said tip, whereby an acute angle ( gamma , gamma '') facing toward said tip is included between the slope of any one of said flanks and said longitudinal axis.
Claim 3
Dependent Claim
16 words
The rock drilling bit according to claim 1, wherein said worm means comprise a double helix.
Claim 4
Dependent Claim
16 words
The rock drilling bit according to claim 1, wherein said worm means comprise a single helix.
Claim 5
Dependent Claim
24 words
The rock drilling bit according to claim 1, wherein said worm means have a depth equal to 0.2 to 0.3 times said given diameter.
Claim 6
Dependent Claim
28 words
The rock drilling bit according to claim 1, wherein said flanks of said worm means have a peripheral thickness corresponding to 0.07 to 0.2 times said given diameter.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |