Patent US3747694A successfully refreshed from Google Patents.
US3747694A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure-medium operated percussion or impact apparatus
Assignee: Moelven Brug AS
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Filing: 1971-12-03
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Granted: 1973-07-24
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Expires: 1991-12-03
Abstract
Abstract A rock drill having a reciprocating piston in a cylinder for striking the drill rod when pressure medium is supplied to alternate sides of the piston, with the piston and cylinder having grooves which on relative rotation of piston and cylinder convey pressure medium to one side or the other of the piston.
Inventors
- 👤 P Kollandsrud
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:17
CPC Classifications
E; E21; E21B; E21B6/00; B; B25; B25D; B25D9/00; B25D9/06; B25D9/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
85 words
A pressure medium-driven or impact apparatus including a cylinder, a working piston in said cylinder, means for supplying pressure to the piston, in which by supply of pressure to alternating sides of the piston the piston is caused to reciprocate, means to rotate the piston, the piston and cylinder being provided with channels which, on rotory movement of the piston relative to the cylinder, open and close the pressure medium channels, with the channels opening at the top and bottom side of the piston respectively.
Claim 2
Dependent Claim
85 words
A pressure medium-driven or impact apparatus including a cylinder, a working piston in said cylinder, means for supplying pressure to the piston, in which by supply of pressure to alternating sides of the piston the piston is caused to reciprocate, means to rotate the piston, the piston and cylinder being provided with channels which, on rotory movement of the piston relative to the cylinder, open and close the pressure medium channels, with the channels opening at the top and bottom side of the piston respectively.
Claim 3
Dependent Claim
23 words
The pressure medium-driven percussion and impact apparatus as claimed in claim 1, in which a motor constitutes the means to rotate the piston.
Claim 4
Dependent Claim
48 words
The pressure medium-driven percussion or impact apparatus claimed in claim 1, in which said piston is provided with axial channels which are open at one side of the piston and closed at the other, and in which every other channel opens toward the same side of the piston.
Claim 5
Dependent Claim
76 words
The apparatus according to claim 2, in which said piston is provided with axially extending channels which open toward the same side of the piston and said cylinder is provided with a passage adapted to pass pressure medium to a chamber on the side of the piston remote from that side where the channels are open, with the piston surface where the channels are open having a greater area than the other side of the piston.
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) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |