Hydraulic Tailstock Cylinder

An auxiliary-function hydraulic system is provided for a computerized numerical control (CNC) machine tooling unit. Hydraulic power is provided for locking collet or chuck to an open or closed position and providing an affirmative collet-open andor collet-closed signal to communicate the collet position to the host computer. The tailstock can be brought gently forward to contact a workpiece and can be returned rapidly to the home position, with a break-away pressure feature being employed to overcome initial static friction
CNC machinery equipment enjoys the advantages of fast machine cycle times, high precision, consistent dimensional accuracy, flexibility of operation, and ease in programming to machine any specific workpiece automatically into a finished, machined product
The machine tool industry has long sought a simple, but reliable hydraulic system that performs the necessary functions, and also provides positive signals to indicate collet open and closed condition, spindle brake actuation, tailstock position and system pressure. Control and signal of the tailstock is especially important so that the tailstock can be brought with gentle but firm pressure against the workpiece to permit handling of light, fragile parts as well as heavy, lengthy, or bulky workpieces. However, until this invention, no completely suitable hydraulic system has been provided for automated machining equipment.