Patent US4144941A successfully refreshed from Google Patents.
US4144941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Directional impact tool for tunneling
Assignee: Individual
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Filing: 1977-09-30
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Granted: 1979-03-20
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Expires: 1997-09-30
Abstract
Abstract A hole-driving tool having an air-operated hammer for impacting against an anvil in the body of the tool to cause the tool to tunnel through the ground, wherein the direction of travel is controlled by providing a variable mass distribution over the hammer and anvil combination, and controlling the relative impact position of the hammer against the anvil.
Inventors
- 👤 Lester L. Ritter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:32
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/36; E21B10/40; E21B4/00; E21B4/06; E21B4/14; E21B4/145; E21B7/00; E21B7/04; E21B7/06; E21B7/068; E21B7/26
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
70 words
In an impact tool for tunneling through the ground by means of a reciprocable hammer which is slidably axially contained within a cylinder having an inner end surface, comprising an anvil having a recession therein in an off-axis position relative to said hammer, and an off-axis mass on said hammer, wherein said off-axis recession in said anvil is complementary-shaped with said hammer off-axis mass and sized to receive said mass.
Claim 2
Dependent Claim
70 words
In an impact tool for tunneling through the ground by means of a reciprocable hammer which is slidably axially contained within a cylinder having an inner end surface, comprising an anvil having a recession therein in an off-axis position relative to said hammer, and an off-axis mass on said hammer, wherein said off-axis recession in said anvil is complementary-shaped with said hammer off-axis mass and sized to receive said mass.
Claim 3
Dependent Claim
16 words
The apparatus of claim 1, further comprising means for rotating said hammer about its sliding axis.
Claim 4
Dependent Claim
43 words
The apparatus of claim 2, further comprising an air hose coupled to said impact tool and means for connecting said air hose to said means for rotating said hammer, whereby twisting of said air hose causes rotation of said hammer about its axis.
Claim 5
Dependent Claim
18 words
The apparatus of claim 1, wherein said cylinder further comprises an exterior pointed surface having circumferential grooves therein.
Claim 6
Dependent Claim
18 words
The apparatus of claim 4, wherein said exterior pointed surface further comprises at least one longitudinal groove therein.
Claim 7
Dependent Claim
98 words
A pressurized air-operated impact tool for directional tunneling through the ground, comprising (a) a cylinder having a tapered front end enclosing a mass having an internal striking surface, said internal striking surface having an off-axis recession therein; (b) a piston axially slidably housed within said cylinder, said piston having an enclosed front end mass having a flat front surface with a raised off-axis projection; (c) air valve means for selectively directing pressurized air against said piston to cause reciprocable axial piston movement within said cylinder; and (d) means for rotatable positioning said piston about its axis of sliding.
Claim 8
Dependent Claim
98 words
A pressurized air-operated impact tool for directional tunneling through the ground, comprising (a) a cylinder having a tapered front end enclosing a mass having an internal striking surface, said internal striking surface having an off-axis recession therein; (b) a piston axially slidably housed within said cylinder, said piston having an enclosed front end mass having a flat front surface with a raised off-axis projection; (c) air valve means for selectively directing pressurized air against said piston to cause reciprocable axial piston movement within said cylinder; and (d) means for rotatable positioning said piston about its axis of sliding.
Claim 9
Dependent Claim
23 words
The apparatus of claim 6, wherein said cylinder mass internal striking surface further comprises a shape complementary with said piston front end mass.
Claim 10
Dependent Claim
29 words
The apparatus of claim 7, wherein said cylinder mass internal striking surface further comprises a recession complementary-shaped with said piston raised off-axis projection and sized to receive said projection.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-19 | 1982-09-18 | 1983-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-19 | 1986-09-18 | 1987-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-19 | 1990-09-18 | 1991-03-20 | $7700.00 | Window Closed / Lapsed |