Tracking head and method of controlling its braking torque

摘要

The head has a first pivot system (4,5) supporting a first pivoting component (1) in a manner which enables it to swivel relative to a base (3). A second pivot system (9,10) supports a second pivoting component (2) which enables it to swivel relative to the first pivoting component. A delay device delays the relative movement of the first pivoting component and the base about a first axis (X) and/or that between the second pivoting component and the first pivoting component about a second axis (Y). The delay device has a liquid chamber (12) containing a fluid the viscosity of which is variable enabling it to act as a control unit. By this means the braking torque about the first and/or the second axis can be adjusted continuously