Patent ID: 7464651

Claim:
A railcar indexing system having carriage-mounted mechanical bogey frame detecting and dog operating systems comprising: (a) a pair of dog carriages mounted for operation in spaced trackside guideways, each dog carriage including a pusher dog mounted on said carriage, each dog having an associated hydraulic dog cylinder for operating the dog; (b) a bogey frame detecting system mounted on each of said dog carriages for use in controlling the operation of each of said dogs and further comprising, (1) detecting assembly including a crank arm-mounted follower positioned to be deflected by the underside of an encountered bogey frame, (2) a spring-biased, normally closed hydraulic valve device connected to control each hydraulic dog cylinder for controlling raising of a connected dog, wherein the opening of said valve is determined by a deflection of said follower in a first direction, (3) a resilient linkage assembly between said follower and said valve for transmitting sufficient force to open said valve.