CURLING ROCK AND APPARATUS AND METHOD FOR DETECTING A HOG LINE VIOLATION

摘要

A curling rock for use in the sport of curling where the rock is expected to be released from a curling player prior to the crossing of a hog line. A part of the roc k is subject to be magnetically activated so that a magnetic field from an activated rock is sensed for detecting the rock's crossing of the hog line. The rock includes: a handle for being touched by a curling player; and an electric circuit for sensing the presence of a curlin g player, the electric circuit including (i) a capacitor coupled to the handle, the capacitance val ue of the capacitor being varied in response to the presence of the curling player at the handle ; and (ii) an activator for magnetically activating a part of the rock in response to the variation of the capacitance value of the capacitor. For example, the handle of the rock may includes a metallic portion. When a curling player touches the metallic handle, the capacitance value is varied and the oscillation frequency is accordingly varied. In response to t he variation of the frequency, a magnetic field is generated by the activating means to activate the rock.