Abstract:
Hammer device comprising a machine housing (1) with a hammer piston (2) movable to-and-fro. The movement to-and-fro of the hammer piston is controlled by a valve body (6) movable to-and-fro in the machine housing. In order to speed up the turning of the hammer piston at its rear end position the machine housing is provided with a room (10) which by the hammer piston is separated from connection with the valve body (6) at the same time as the rear end surface (5) is supplied with pressure fluid via a connection (11) opened by the hammer piston to the pressure source (8) when the hammer piston approaches its rear end position.
Abstract:
Rock drilling device comprising a backhammer unit (10) in which a hammer piston (9) is movable to-and-fro for automatically exposing a tube string (4) to impacts in a direction away from a drill bit (8) in the tube string. The backhammer unit comprises a housing (13) and a springloaded tube part (14). The housing and the tube part form between them a first valve (16) and a second valve (17). At drilling the first valve which controls the supply of driving medium to said hammer piston is closed and the second valve which controls the flushing medium flow is open. At backwards feeding of the rock drilling machine (2) along the feed beam (1) with a force which exceeds a predetermined value the first valve is open and the second valve is closed.
Abstract:
The invention includes an arrangement for manufacturing an elongated object (4) including, inter alia, a fibrous material, by compressing (7,8) a quantity of fibrous material provided with a binding agent and drying the compressed fibrous material by passing the material between the electrodes of a high-frequency drier (5). One electrode (12), preferably both electrodes (12, 13) of the drier is/are arranged to co-act with an electrode-heating device (16).
Abstract:
A projectile adapted to be given a rotation on being fired which makes the projectile spin-stabilized.With the object of facilitating the terminal guidance of the projectile or increasing the effect of an explosive charge with a hollow-charge effect carried by the projectile, the projectile is provided with stabilizing fins (6-9) which are extended at a desired point in the trajectory of the projectile and brake the rotation of the projectile. The projectile is so dimensioned that its center of pressure (C2) is situated behind the center of gravity (G) of the projectile in the extended position of the fins (FIG. 2) and so that the center of pressure (C1) lies in front of the center of gravity of the projectile in the retracted position of the fins (FIG. 1), so that, with braked rotation, the projectile changes over from being spin-stabilized to being fin-stabilized.The fins (6-9), which can consist of so-called wrap-around fins, are held in the retracted position, in an embodiment shown, by covering plates (2-5) which are held in place by a so-called base bleed unit (1). A delay device is adapted to be separated from the projectile at the desired point in the trajectory, so that the covering plates (2-5) are removed and expose the fins (6-9), as a result of which these can be extended.