KEYBOARD CONTROLLED ENCODING MECHANISM

A keyboard controlled encoding mechanism employs a continuously rotating snatch roll to drive translatable interposers which, when driven, operate code selector bails. The interposers are normally biased toward engagement with the snatch roll but are held latched by release levers rockably responsive to key depression. A rocked release lever releases its associated interposer and moves into a ball lock precluding depression of a second key. The release lever is held in the ball lock by its interposer until moved out incident to movement of its associated interposer to a limit. During movement of the interposer to its limit a code for processing will be generated. The same movement of the interposer moves the release lever to a position where it can relatch its interposer. The movement of an interposer also positions a bistable blocking bail to preclude engagement of another interposer which however can be unlatched by its associated release lever and placed in readiness or memory as soon as the first release lever leaves the ball lock. The interposer in memory immediately moves into engagement with and is driven by the snatch roll as soon as the blocking bail is restored in response to a signal from the system acting on or processing the code generated.