Patent ID: 7572175

Claim:
A coolant supply apparatus for a grinding machine having a grinding wheel attached to a wheel spindle rotatably supported by a wheel head, a coolant supply nozzle connected to a coolant supply through a conduit for supplying coolant toward a grinding surface of the grinding wheel, and a shut-off valve provided on the conduit for allowing the flow of coolant toward the coolant nozzle when in an open state and for blocking the flow of coolant when in a closed state, the apparatus further comprising: wheel imbalance prevention means operable within the period from the switching of the shut-off valve to the closed state to a stop in rotation of the grinding wheel, for preventing the coolant remaining in the coolant nozzle from dropping on the grinding surface of the grinding wheel so that the grinding wheel is not put out of balance due to the coolant which would otherwise drop on the grinding surface.