(under subclass 131) Subject matter having switch-stands where the signal and switch do not move simultaneously, but independently, in a prearranged sequence of operation.
SEE OR SEARCH THIS CLASS, SUBCLASS:
111, through 119, for manual interlocking at grade-crossings and drawbridges.
278, 284, 290, and 393, and the appropriate indented subclasses, for switch-stand structure.
SEE OR SEARCH CLASS
74, Machine Element or Mechanism,
483, for mechanism for the interlocking of two or more levers or cranks.
