BELL TELEPHONE MANUFACTURING Co.
(BTMC) ANTWERP
Telephone No. 2678 and 2679

Pictures dated 1923

TELEPHONES FOR CENTRAL BATTERY NETWORKS
THE INTEGRAL AUTOMATIC SYSTEM

A SPECIAL TELEPHONE ALLOWING A CALL TO BE MADE AND OBTAINED COMMUNICATION WHILE MAINTAINING AN INITIAL CONNECTION

The objective proposed above is achieved by means of different telephones.

The telephones, described below, fulfill this dual role.

1. Table Telephones No. 22678 and 72678 with black lacquered sheet metal casing and nickel-plated on exposed metal parts.

These are designed for connection to both a shared battery network and an automatic central (private) automatic system. In addition to ordinary equipment, the handsets are used with the No. 2386 magneto Bellset which contains 2 capacitors and 2 ringers. These latter rings are equipped with different ringtones to identify the caller.

With these telephones, it is possible to answer the call from the private exchange just be lifting the handset. To call the private exchange, the sender will be activated and the current one is used with the ordinary handsets.

To answer the call from the central office, or to call it, it will be necessary to press the button mounted on the handset. Furthermore, these handsets are equipped with a lever key that allows switching between a holding resistance on the line, which isolates the telephone and on the levers return is again connected to the private exchange.

The point of the hold lever makes it possible to connect to another extension on the private line while maintaining the connection to the central office.

To re-establish the first interrupted communication, it will suffice to press the button that had automatically popped up following the operation of the key. By replacing the telephone in the switch cradle, the button and lever return to their normal position.

2) Table telephone models No. 22679 and 72679 are made from Black painted steel and Nickel plated on all exposed metal parts.

These telephones are similar to models No. 22678 or 72678 but are designed to allow the line to be maintained on the private exchange while the central office is called. The conversation can be transferred from any line to the other without interruption. After ending the conversation on one of the two lines, it is possible to release it while maintaining communication with the other.

3. Tabletop sets 22680 and 72680 have a steel casing painted black and nickel-plated on all exposed metal parts.

These telephones are designed for use in all private networks.

The usefulness of the interlocking devices allows for re-routing a second line.

At the moment of operation, it will be possible to obtain communication with the telephone.

Rating order and the centrally located unit, while the switchboard will maintain communication with the line regularly. The central unit will not, however, be able to call the station via this switch. The additional devices are operated by a button and a lever. The button connects the telephones to the second line. The switchboard maintains the first connection. By pressing the lever, the button is used. returns to its normal position. And this inan4euvre cuts the second communication while re-establishing the first.

4. Table telephones No. 22681 and 72681 are supplied in a black painted steel casing, with all exposed metal parts nickel-plated.  These telephones are similar to the No. 22680 and 72680, of which they possess the same characteristics, but they are equipped with a key, the position of which is normally in the down position. In the event that one wishes to momentarily return to a regular line without interrupting communication with the second control. To resume the conversation with the latter, full pressure is required on the key button. This maneuver will isolate the regular line again and will restore conditions C and D so the link will be connected to the second line, while maintaining the regular line.

22678
Steel cased telephone, for manual areas, with a handset, two keys and rosette terminal block.

72678
Steel cased telephone, for automatic areas, with a dial, handset, two keys and rosette terminal block.

22679
Steel cased telephone, for manual areas, with a handset, two keys and rosette terminal block.

72679
Steel cased telephone, for automatic areas, with a dial, handset, two keys and rosette terminal block.

Taken from the BTMC Catalogue - 1924

Click here for Models No. 22680, 72680, 22681 and 72681