Northern Telecom Limited

Algirdas J Dragunevicius

Gerd Kuhfus

Beverley W Gumb

George V Lenaerts

Charles R Walker

Eugene W Charchanko

Ronald J Morrell

A base-plate for a telephone set base has a bottom web or panel, with a wall extending upward around the panel for the majority of its periphery. At one side an inclined web extends inward and upward and a wall extends round the periphery of the web, with an aperture formed in the bottom panel coincident with the inclined web. The inclined web, and the wall around the web define a lower recess and an upper recess. A further recess in the bottom panel, closed on three sides and top and open on the fourth side provides access for modular plugs of the handset cord and line cord. Enclosed channels extend from the upper end and lower end to the further channel for passage of line and handset cords. A further enclosed channel extends from the lower recess to the channel from the upper end for alternate positioning of a short line cord in a wall mounting mode. Mounting means for a circuit board, hook switch and piezoceramic transducer are provided.

Base plate for telephone set base

A line switch assembly for a telephone switch has a unitary switch having a base within which are cantilevered contacts and a cap over the base, the cap having cam formations which actuate the contacts on reciprocal movement of the cap. An actuating member rests on the cap and has an extension with a rib which extends up into a recess in the top housing of the telephone set, the recess being one which accepts one of the handset transducers. Pressure on the rib pivots the actuating member and depresses the cap. The switch is a preassembled unit and is normally mounted on a circuit board carrying other components. A reduced number of components and quicker and easier assembly give a relatively high cost reduction.

Simplified line switch for a telephone set

A telephone transmitter sub-assembly has an electret clamped between a pair of printed circuit boards. The electret conducting surface and printed circuit patterns on the boards have an overlapping arrangement at a planar junction. The arrangement connects a capacitor, of which the electret forms part, into an amplifying circuit.

Electret microphone with simplified electrical connections by printed

A base plate for a telephone set is molded of plastic instead of being a metal stamping and can be made of recycled scrap plastic material. The base plate is provided with a plurality of positions for mounting telephone set parts with each position having an arrangement of projections and one or more deflectable members whereby the telephone items can be mounted by sliding and downward movement to clip in, and with one or more of the positions also having alternative means for mounting items whereby alternate forms of an item can be interchangeably mounted.

Growing community of inventors

London, Canada

Algirdas J Dragunevicius