GB703804A - Improvements in automatic electrical message keying mechanisms - Google Patents

Abstract

703,804. Telegraphic transmitters. WALLACE & TIERNAN, CO., Inc. Dec. 3, 1951 [Dec. 6, 1950], No. 28304/51. Class 40 (3) An automatic electrical keying device for a predetermined message comprises a stationary control surface with a contour representing the message to be keyed, along which a sensing member is repeatedly driven to respond to changes of level of the contour and control the operation of a switch accordingly and in which the contour of the control surface is constituted by a number of settable elements which can be individually preset so that each forms either a high level or a low level of the contour. Keys 25 arranged in three rows carry enlarged ends 32 which in the depressed position engage laterally displaced sensing members constituted by rollers 72, 73, 74 mounted on rods 62, 63, 64 carried between looped chains 50, 51 driven by sprockets 56, 57 from gearing 102, 103 and a motor 100 The keys which are depressed to form the code elements of the characters forming a message are locked by turning each key through 90 degrees so that a pin 38 engages in a transverse slot 44 in a flange 42. The engagement of a roller 72, 73 and 74 with the enlarged end 32 of a depressed key moves downwardly a platen member 75, carried by two pairs of spaced parallel arms 77, so that a switch arm 93 carrying a roller 94 in engagement with the platen 75 is rocked to close contacts 92. The platen 75 is biased to its upper position by springs 84 attached to one pair of arms 77 and its upper position is adjustably determined by a set screw 82 mounted in an extension 80 of one of the other pair of arms 77 and in engagement with the surface of a member 60 fixed in the framework of the machine. The heads of the setting keys may have diametrical lines 46, or grooves which, by their position, show the operations of the successive keys for dots, dashes, spaces between code elements and between letters. In a modification, Figs. 5, 6, 7 (not shown), the message is set up by individual element members disposed in parallel slots and having short and long shanks. The dashes and long spaces may be set up by members having the length of three dot members or three short spacing members or by using three dot members and three separate short-space members. In a further modification, Figs. 8, 9 (not shown), four rows of keys are used, and a lengthened path is provided for the conveyor chains carrying the four laterally displaced sensing members.