GB1258786A - - Google Patents

Abstract

1,258,786. Keyboards for printers. TELETYPE CORP. 23 Jan., 1969 [29 Jan., 1968], No. 3742/69. HeadingB6F. A keyboard for a teleprinter includes a plurality of key levers 55 each associated with an encoding device, depression of the key lever acting first to move the encoding device to an operative position and subsequently to disengage the key lever from the encoding device so that the encoding device can return to an inoperative position. Each encoding device comprises a shutter 106 having tabs 112 capable of closing light paths 110 and a universal tab 113 capable of closing a light path 111. On depression of the key lever 55, a lever 90 is caused to pivot at 92 and bring a finger 95 into engagement with a pin 114 on the tab 113. The shutter 106 is thereby rotated against a spring 116 for further depression of the key lever 55 until the arcuate paths of travel of the finger 95 and pin 114 diverge, when the shutter 106 is released. At the time of release, the tab 113 blocks the light path 111 but the tabs 112 have passed their respective light paths 110 (Fig. 3A, not shown). In this position, light detectors are primed so that as the shutter returns, the light passing along the paths 110 is detected when the path 113 becomes unblocked. At this moment, the tabs 112 are blocking their respective light paths 110 (Fig. 3B, not shown), and a coded signal is generated. Repeat action.-The key lever 55 is formed with a tab (120), Fig. 2 (not shown), capable of blocking a light path 121, Fig. 3, under full depression of the key lever. While the light path 121 is blocked, the character corresponding to the key lever depressed is repeatedly generated. If the character is not required repeatedly, the tab (120) may be broken away from the key lever.