Abstract: The present invention relates to a method for determining state of at least one joint of a drill string of a drill rig, the drill rig including a percussion device for inducing shock waves into the drill string, and a sensor for sensing stress waves in the drill string caused by impacts of the percussive device, the method comprising, when a stress wave is induced into the drill string by the percussive device: determining a representation of the incident stress wave caused by the percussive device; determining a representation of a reflected wave representing a reflection of the incident stress; estimating a stiffness of the at least one joint by estimating a force exerted on the at least one joint by the incident wave.

Abstract: The present invention relates to a method for optimising at least one drilling parameter during an ongoing drilling process, the drilling being carried out by a percussive drilling machine, the drilling machine being set to drill at an operating point, the operating point of the drilling being determined by a setting of a plurality of control parameters. The method includes determining a first plurality of drilling machine operating points, the operating points being set by the plurality of control parameters. Furthermore, percussive drilling is performed at each of the first plurality of operating points and at least one resulting drilling parameter is evaluated for each of the plurality of operating points. The method also includes determining a new plurality of drilling machine operating points.

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 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: Rock drilling equipment and drill string components (2;18) for top hammer drilling and down-the-hole drilling for positioning between a drill rig and a drill bit include a pipe-shaped element (3;19), which is arranged for transferring only rotational movements from the drill rig to the drill hit. A vibration-damping structure (12) is arranged adjoining to at least a part of an inside (11) of the pipe-shaped element in a space (41) formed inwardly of the inside (11).

Abstract: Drill string components (2;18) for top hammer drilling and down-the-hole drilling for positioning between a drill rig and a drill bit including a pipe-shaped element (3;19), which is arranged for transferring only rotational movements from the drill rig to the drill bit. A vibration-damn ins structure (12) is arranged adjoining to at least a Dart of an inside (H?) of the pipe-shaped element in a space (41) formed inwardly of said inside (H?). The invention also concerns a rock drilling equipment.