NATIONAL TELEPHONE COMPANY
B530

BATTERY INTERCOMMUNICATION TELEPHONES

AUTOMATIC INTERCOMMUNICATION WALL SET (PUSH BUTTON)

Wall Set

Pattern No. B530

Comprises - Hand Combination Transmitter and Receiver, Cord, Automatic Cradle-switch, Induction Coil, Buzzer, and Special Push Button Line Selector.

The Push Button Line Selector is arranged so that the selection of a line is accomplished by simply pushing in the button, the number of which corresponds with the number of the station required.  This button, when pushed right home, connects the battery, and sends the calling current to the line.  When the pressure is removed from the button it only partly returns towards its original position, leaving the instrument connected to the line which has been selected.

When the conversation is finished, and the Hand Micro-telephone replaced on the Automatic Switch, the button of the line which has been in use regains its normal position.  When a call is received all that has to be done is simply to take up the Hand Combination, and reply in the ordinary way. If any of the buttons have been left in, the pressing of a further one immediately restores them to their normal position.

The terminals are quite hidden, and thus free from being able to be tampered with, also the wiring can be done after the instrument has been screwed up.  The terminals are concealed by a panel moulding shewn in the illustration round the Line Selector push buttons.

The function of the Automatic Switch is two-fold:

Firstly : To disconnect the ringing battery when the Hand Micro-telephone is hung up, so that should mischievous persons press in any of the ringing keys without having first lifted the Hand Micro-telephone, the battery does not get connected to that line, otherwise an unnecessary call would result.

Secondly: By engaging in the mechanism of the Line Selector to cause the push button which has been operated to regain its normal position.

The whole of the instrument is solid Walnut, well polished, and highly finished.

If desired, conversation can be carried on with one, two, three, or more stations at the same time by pressing in the respective buttons together.

5, 10, 15, 20, 25 & 30 line models.

Was B72 in the 1903 Catalogue.
 

Last revised: July 07, 2020