| Patent Number |
Title Of Patent |
Date Issued |
| 4964477 |
Pneumatic percussive device |
October 23, 1990 |
| A pneumatic percussive device has a casing (1) accomodating a movable hammer piston dividing the interior space of the casing (1) into two chambers. One of these chambers (7) alternately communicates, by means of an air distribution arrangement (3) having a movable actuator member (8), |
| 4733731 |
Air-operated reversible percussive action machine |
March 29, 1988 |
| An air-operated reversible percussive action machine comprises a housing (1) accommodating a reciprocating hammer (2). Secured inside the housing (1) is a stepped tube (5). The step of larger diameter of the tube (5) is received by a cavity (4) of the hammer (2) and has a port (12) for |
| 4708211 |
Reversible air-operated percussive action machine for driving holes in the ground |
November 24, 1987 |
| A reversible air-operated percussive action machine for driving holes in the ground has a housing accommodating a hammer 2 capable of reciprocating therein. An air distributor 3 is arranged in the hammer 2 in the form of a fixed tube 12 and a valving member 13 movable relative to the tub |
| 4690225 |
Percussive tool |
September 1, 1987 |
| A percussive tool comprises a percussion mechanism and a pressure pulser. The percussion mechanism has a hollow housing with a piston hammer arranged thereinside to form two chambers of variable volume. The pressure pulser has a hollow housing and a fluid displacer defining inside the |
| 4363365 |
Impact tool with damping chambers |
December 14, 1982 |
| A pneumatic percussive tool has a barrel in which is inserted a hammer piston imparting blows at a working tool at regular intervals. A floating sleeve surrounding the working tool is provided in the front end portion of the barrel, the sleeve having a projection defining with a barrel |
| 4280573 |
Rock-breaking tool for percussive-action machines |
July 28, 1981 |
| A rock-breaking tool for preferable use in self-propelled percussive machines for boring wells, comprising a casing with a pointed portion and an end face. The casing has an annular cutting edge formed by the pointed portion and inner tapered surface thereof. The casing is formed with a |
| 4214638 |
Method of controlling the reversing of a device for driving holes in earth and device for perfor |
July 29, 1980 |
| A percussive device operable in a forward mode for making a hole in soil and operable in a reverse mode to retract the device from the hole. The device is provided with control means that change the mode of operation alternatively under control of a valve that turns air pressure on and o |
| 4132277 |
Pneumatic reversible impact device for driving holes in soil |
January 2, 1979 |
| The device comprises a hollow cylindrical body, pointed front at its end which device accommodates a striker forming the front working chamber in said body, and has a cylindrical space at its rear end. Said space receives an air-distributing and reversing mechanism, thus forming the |
