Abstract: Roller skate comprising a plate (1) for the user's foot and one front wheel (2) and a rear wheel (3) having a convex curved running surface and rotably mounted on shafts (7, 5). One wheel is pivotable between side angle positions on either side of a center position in which the direction of rolling of the wheel concerned extends in the longitudinal direction of the skate. A steering mechanism (15) is provided for pivoting of the wheel (2) and having a sensing member (22) which is arranged to rest against the subsurface on which the wheel is designed to roll. The sensing member is connected with the pivotable wheel in such a way that the angle of pivoting is governed by the inclination of the skate in relation to the subsurface, due to the member resting against the subsurface.

Abstract: An apparatus for automatically aligning logs to be sawn in a sawing machine in a position for yielding an optimum sawing result, comprising an arrangement for carrying the log to be aligned in a predetermined vertical longitudinal plane through the sawing machine, and a device for turning the log. The apparatus further comprises sensing members, which are connected to an evaluation which, control unit and by external sensing the log by the sensing members, records changes of the log center in relation to the longitudinal plane during one revolution of the log. Thereafter, the unit on the basis of information received determines the optimum alignment position and permits the turning device to turn the log into this position.