Abstract: A head drum apparatus comprises: a lower drum; a stationary shaft pressed and fitted into a center hole of the lower drum; an upper drum rotatably coupled to the stationary shaft via at least one bearing; a boss fixed to the top portion of the stationary shaft by means of a set-screw; a motor rotor mounted to the top surface of the upper drum; a motor stator fixed to the boss, the motor stator being opposite to the motor rotor; and a ground device. The ground device includes an anchor member anchored to the upper surface of the boss and an elastic member fixed to the bottom surface of the anchor member. The elastic member extends downwardly through a bore in the boss, and a ground member is fixed to tile lower end of the elastic member. The ground member is in elastic contact with an outer race of an upper bearing.

Abstract: A magnetic recording/reproducing apparatus, having a driving source; a main chassis on which the driving source is mounted; a sub chassis which is disposed to the main chassis so as to be slid in a front and rear direction, and which is provided with various tape running elements; a head drum device which is mounted on the main chassis; a loading system provided with a supply side pole base driving device and a winding side pole base driving device which loads a tape depending on the moving operation of the sub chassis in the front and rear direction; a running system which runs the tape in a desired direction at a desired speed; a main power transmitting unit which selectively transmits a power of the power source to the loading system or the running system; a cam gear which is rotated by the main power transmitting unit and transmits the power to each mode; a slider which is disposed between the main chassis and the sub chassis so as to be slid in a left and right direction and interlocked with the cam gear

Abstract: The present invention relates to a subscriber control module having a test apparatus suitable for testing internal routes in an Asynchronous Transfer Mode ATM exchange system for improved reliability and effective maintenance thereof. A subscriber control module having testing functions makes it possible that internal whole routes in the exchange system under the control by maintenance control module inside the system can be tested through the use of subscriber switching network and connection switching network. Further, a test apparatus of the present invention placed inside the exchange system can test ATM subscribers with individually different rates, configured in such a way to be identical with boards used in the exchange system so that the test apparatus can be installed inside the exchange system.