Position indicating apparatus for crane ways, overhead conveyors, and the like

Abstract

A position indicating apparatus for crane ways and overhead conveyors and the like includes a code carrier (11), which carries multi-value code marks (18) in one track along its length. The code marks (18) are combined into blocks (17), with which a block identification (22) is associated. Cooperating with the code carrier (11) and the block identification (22) are a code reader (12) and an auxiliary reader (24), respectively. Along the travel path, the code carrier (11) and the code reader (12) are disposed counter to one another. To enable increasing the length of the addressable travel paths without losing positional accuracy, or without having to increase the number of code marks (18) in one code word (35), a block identification (22) is associated with the blocks (17). From the block identification (22), an auxiliary reader (24) can recognize whether the code reader (12) is reading only code marks (18) from one block (17). In this way, the travel path can be divided into important zones (27), in which the accurate position of the vehicle must be known, and to which blocks (17) must therefore be assigned, and unimportant zones (28), which are merely gaps (19) between blocks that connect the important zones (27) to one another.

Dependencies are inferred from the claim text.