US4366868A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rock drill apparatus
Assignee: Tampella Oy AB
•
Filing: 1979-05-07
•
Granted: 1983-01-04
•
Expires: 1999-05-07
Abstract
Abstract A striking apparatus that includes a reciprocating striking piston operable by a pressure mechanism, a cylindrical body, the improvement comprising a sleeve bushing mounted inside of the cylindrical body in slidably fitted assembly therewith. The sleeve bushing has a drive gear at one end for rotary engagement with a drive motor. A rotary tool and piston shank and piston are all integrally combined as a one piece unit and at least partly received in coaxial alignment within the tubular bushing. Spline gearage exists between the tubular bushing and the piston shank enabling co-rotational rotary movement together upon actuation of the drive gear through operation of a drive motor operatively connected therewith. A piston cylinder in the cylindrical body along with the piston is reciprocably movable in the piston cylinder. The shank has a shank face facing in the direction opposing the striking piston and with the shank face transferring the feed force from the body through the sleeve bushing to the rotary tool. There is structure cooperable with the piston cylinder for assisting a pressure medium to be directed towards the front of the piston so that the latter moves backwards towards the striking piston causing a striking contact between an end surface of the shank and the striking piston when the tool becomes stuck.
Inventors
- 👤 Pekka Salmi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:35
CPC Classifications
E; E21; E21B; E21B31/00; E21B31/107; B; B25; B25D; B25D17/00; B25D17/08; B25D17/084; B25D2250/00; B25D2250/171
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
215 words
In a striking apparatus including a reciprocating striking piston operable by a pressure mechanism, a cylindrical body, the improvement comprising a sleeve bushing mounted inside of the cylindrical body in slidably fitted assembly therewith, the sleeve bushing having a drive gear at one end for rotary engagement with a drive motor, a rotary tool and piston shank and piston all integrally combined as a one piece unit and at least partly received in coaxial alignment within said tubular bushing, spline gear means between the tubular bushing and the piston shank enabling co-rotational rotary movement together upon actuation of the drive gear through operation of a drive motor operatively connected therewith, means defining a piston cylinder in the cylindrical body and with the piston being reciprocably movable in the piston cylinder, the shank having a shank face facing in the direction opposing the striking piston and with the shank face transferring the feed force from the body through said sleeve bushing to the rotary tool, and means cooperable with the piston cylinder for assisting a pressure medium to be directed towards the front of the piston so that the latter moves backwards toward the striking piston causing a striking contact between an end surface of the shank and the striking piston when the tool becomes stuck.
Claim 2
Dependent Claim
215 words
In a striking apparatus including a reciprocating striking piston operable by a pressure mechanism, a cylindrical body, the improvement comprising a sleeve bushing mounted inside of the cylindrical body in slidably fitted assembly therewith, the sleeve bushing having a drive gear at one end for rotary engagement with a drive motor, a rotary tool and piston shank and piston all integrally combined as a one piece unit and at least partly received in coaxial alignment within said tubular bushing, spline gear means between the tubular bushing and the piston shank enabling co-rotational rotary movement together upon actuation of the drive gear through operation of a drive motor operatively connected therewith, means defining a piston cylinder in the cylindrical body and with the piston being reciprocably movable in the piston cylinder, the shank having a shank face facing in the direction opposing the striking piston and with the shank face transferring the feed force from the body through said sleeve bushing to the rotary tool, and means cooperable with the piston cylinder for assisting a pressure medium to be directed towards the front of the piston so that the latter moves backwards toward the striking piston causing a striking contact between an end surface of the shank and the striking piston when the tool becomes stuck.
Claim 3
Dependent Claim
188 words
In a striking apparatus including a reciprocating striking operable by a pressure mechanism, a cylindrical body, a sleeve bushing mounted inside of the cylindrical body in slidably fitted assembly therewith, means for driving the sleeve bushing, the improvement comprising a rotary tool and piston shank and piston all integrally combined as a one piece unit and at least partly received in coaxial alignment within said tubular bushing, means between the tubular bushing and the piston shank enabling co-rotational rotary movement together upon being driven, means defining a piston cylinder in the cylindrical body and with the piston being reciprocably movable in the piston cylinder, the shank having a shank face in the direction opposing the striking piston and with the shank face transferring the feed force from the body through said sleeve bushing to the rotary tool, and means cooperable with the piston cylinder for assisting a pressure medium to be directed towards the front of the piston so that the latter moves backwards toward the striking piston causing a striking contact between an end surface of the shank and the striking piston when the tool becomes stuck.
Claim 4
Dependent Claim
188 words
In a striking apparatus including a reciprocating striking operable by a pressure mechanism, a cylindrical body, a sleeve bushing mounted inside of the cylindrical body in slidably fitted assembly therewith, means for driving the sleeve bushing, the improvement comprising a rotary tool and piston shank and piston all integrally combined as a one piece unit and at least partly received in coaxial alignment within said tubular bushing, means between the tubular bushing and the piston shank enabling co-rotational rotary movement together upon being driven, means defining a piston cylinder in the cylindrical body and with the piston being reciprocably movable in the piston cylinder, the shank having a shank face in the direction opposing the striking piston and with the shank face transferring the feed force from the body through said sleeve bushing to the rotary tool, and means cooperable with the piston cylinder for assisting a pressure medium to be directed towards the front of the piston so that the latter moves backwards toward the striking piston causing a striking contact between an end surface of the shank and the striking piston when the tool becomes stuck.
References Cited (Backward Citations)
US1080095A
Cited
DE475805C
Cited
US2083261A
Cited
US2226559A
Cited
SE325239B
Cited
US3583499A
Cited
US3625295A
Cited
US3827507A
Cited
FI763159A7
Cited
US4109734A
Cited
US4206820A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-01-03 | 1986-07-05 | 1987-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-03 | 1990-07-05 | 1991-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-03 | 1994-07-05 | 1995-01-04 | $7700.00 | Window Closed / Lapsed |