Bell Telephone Laboratories

At&t Bell Laboratories

American Telephone and Telegraph Company; At&t Information Systems

Francis S Doyle

John N McGarvey

Donald M Genaro

Terry B Prince

Arlan K Andrews

Robert L Beecher, Ii

Martin James Stevenson

Randall W France

A line switch for a telephone set comprises a lever rockably mounted in the tand for the set and having as a rear part a plunger fin received in a slot passing through the stand to a handset cradle on its top. The lever has at its front a head carrying on its underside a pair of metal leaf springs of which front portions form spring contacts disposed over corresponding electroconductive pads on a printed wiring board mounted within the stand. The lever is biased by a torque spring to yieldably hold the upper part of the fin in the cradle. Removal and replacement of a handset from and to the cradle actuates the lever to produce engagement and disengagement, respectively, of the spring contacts with their corresponding pads. Such spring contacts and pads form, electrically speaking, a line switch adapted upon such engagement and disengagement, respectively, to produce a 'short' and an 'open' of terminations at the set of the tip and ring leads therefor.

Telephone set line switch

Housing for an automatic dialing telephone set or similar article

To reduce manufacturing costs of telephone instruments it is desirable to secure components to housing members and secure housing members to one another without the use of fasteners. In the past this has been accomplished by the use of flexible latch elements that are deflected from their normal position in the process of assembly, and then return to their normal position to perform their latch function when assembly is complete. The problem with this arrangement is that impact, such as occurs during shipping or when a telephone instrument is accidentally dropped, has been found to cause the flexible latch elements to deflect and release the housing members and/or components they are intended to secure. The disclosed telephone instrument solves the problem of securing the components in place by having integral flexible latch elements (115) extend alongside of a wall (140) of one housing member (100) and integral blocking elements (245) included in the mating housing member (200). These elements are arranged so that when the two housing members are joined together, the blocking elements extend between the wall and the latch elements and prevent the latch elements from deflecting while the housing members are joined. The disclosed telephone instrument solves the problem of securing the housing members together by interlocking one end and latching the other end of the housing members. The latching is achieved by having inflexible latch elements (135, 235) integral to each housing member move into interlocking engagement by means of flexing the adjacent wall (130) of one housing member (100).

Construction of a telephone instrument

Telephone enclosure

Growing community of inventors

Oaklandon, IN, United States of America

Francis S Doyle