Punched card system for coding numbers - has perforation positions arranged as grid to punch characteristic patterns which may be sensed by appropriate equipment

摘要

A punched card is used esp. for specifying which resonators of a responder in a microwave railway control system are to be activated. The system permits an observer to check easily from visual observation of the card, what code number it represents. The card is provided with an orthogonal grid of perforations (P) separated by intermediate zones (Z) which are marked off by boundary lines. The perforations may be pre-prepared by crossed slits to facilitate manual marking by a blunt tool to produce a characteristic pattern representing a given code.