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.