Abstract: A pulsed power drilling tool configured for passing a pulsed electrical current through a mineral substrate to break the mineral substrate, the drilling tool including: a pulsed power generator for generating high voltage current pulses, a drill head including at least one pair of a first electrode and a second electrode, the first electrode including a first solid electrode portion and the second electrode including a second solid electrode portion, the first and second solid electrode portions being galvanically connectable to the pulsed power generator, and at least one ionization device configured for generating at least one ionized fluid volume extending at least from the first solid electrode portion to a surface of the mineral substrate, to allow a high voltage current pulse to pass between the first solid electrode portion and the second solid electrode portion via the at least one ionized fluid volume and the mineral substrate.

Abstract: A method for estimating a level of stress that a mine truck is subjected to. The mine truck includes a frame; a container for carrying payload supported by the frame; and at least one sensor, the at least one sensor delivering signals being dependent on a force acting on the mine truck. The method includes for at least a first position of the frame, estimating a level of stress that said at least a first position is subjected to in response to a force acting on the mine truck, wherein said at least a first position is a position being different from the position of said at least one sensor; and estimating said level of stress utilising a model representation of the level of stress for said at least a first position wherein said model representation output said estimated level of stress utilising sensor signals from said at least one sensor as input signals.

Abstract: A pulsed power drilling tool configured for passing a pulsed electrical current through a mineral substrate to break the mineral substrate, the drilling tool including: a pulsed power generator for generating high voltage current pulses, a drill head including at least one pair of a first electrode and a second electrode, the first electrode including a first solid electrode portion and the second electrode including a second solid electrode portion, the first and second solid electrode portions being galvanically connectable to the pulsed power generator, and at least one ionization device configured for generating at least one ionized fluid volume extending at least from the first solid electrode portion to a surface of the mineral substrate, to allow a high voltage current pulse to pass between the first solid electrode portion and the second solid electrode portion via the at least one ionized fluid volume and the mineral substrate.

Abstract: A method for determining efficiency of a drilling process comprising the steps of: transferring energy via a tool member to the material in which drilling is to be performed by means of a drilling configuration; detecting waves which are propagating in said tool member of said drilling configuration during drilling as a result of energy provision; detecting said waves by means of at least two sensor means arranged on mutually opposite sides of said tool member adjacent to, on a certain distance from, said tool member, which sensor means are based on inductive and/or capacitive detection of said waves in said tool member; and based on results of said detection, determining said efficiency of said drilling process.

Abstract: A method for estimating a level of stress that a mine truck is subjected to. The mine truck includes a frame; a container for carrying payload supported by the frame; and at least one sensor, the at least one sensor delivering signals being dependent on a force acting on the mine truck. The method includes for at least a first position of the frame, estimating a level of stress that said at least a first position is subjected to in response to a force acting on the mine truck, wherein said at least a first position is a position being different from the position of said at least one sensor; and estimating said level of stress utilising a model representation of the level of stress for said at least a first position wherein said model representation output said estimated level of stress utilising sensor signals from said at least one sensor as input signals.

Abstract: A method for determining efficiency of a drilling process comprising the steps of: transferring energy via a tool member to the material in which drilling is to be performed by means of a drilling configuration; detecting waves which are propagating in said tool member of said drilling configuration during drilling as a result of energy provision; detecting said waves by means of at least two sensor means arranged on mutually opposite sides of said tool member adjacent to, on a certain distance from, said tool member, which sensor means are based on inductive and/or capacitive detection of said waves in said tool member; and based on results of said detection, determining said efficiency of said drilling process.

Abstract: A device in a hydraulic rock drilling machine (1) has a distribution valve (7, 7?, 7?) for controlling hydraulic flow to different parts of the rock drilling machine. The distribution valve has a valve body (8, 8?, 8?) which moves to and from in an axial direction inside a valve chamber (33). The valve chamber is limited in axial direction by two valve end walls (10, 11; 10?, 11?; 10?, 11?). One of the valve end walls is movable in an axial direction against an abutment (12, 12?) to define an end position for the valve body, and a pressing device (13, 13?, 13?) is provided for pressing at least one of the valve end walls against the abutment. A rock drilling machine includes the device.

Abstract: A device in a hydraulic rock drilling machine (1) including a distribution valve (7,7?, 7?) arranged in connection with the rock drilling machine for controlling hydraulic flows to different parts of the rock drilling machine, wherein the distribution valve includes a valve body (8, 8?, 8?), which is arranged movable to and fro in axial directions inside a valve chamber (33) and wherein the valve chamber is limited in axial direction by two valve end walls (10,11; 10?,11; 10?,11?). One of the valve end walls is movable in an axial direction against an abutment (12,12?) in such a way that it defines an end position for the valve body, and a pressing device (13,13?,13?) is arranged for pressing said at least one of the valve end walls against said abutment. The invention also relates to a rock drilling machine.

Abstract: In a push button operated telephone set to be used in a telephone system designed for break/make impulsing an electronic circuit is used for converting the push button signals to break/make pulse trains. In order to supply power to the electronic circuit from the central battery through the subscriber's line even if the terminal voltage is low at the subscriber, a DC voltage converter is used in the set to multiply the terminal voltage. This converter includes a pulse oscillator which is also used as a timing pulse generator for the electronic circuit, controlling the frequency, make/break ratio and pulse sequence intervals of the dial pulse trains sent to the exchange.