Power operated sawing tool

Claim 1

IN A POWER OPERATED ASSEMBLY, A ROTATABLY DRIVEN TOOL HAVING CUTTING ELEMENTS, A FLUID MOTOR, TORQUE TRANSMITTING DRIVE MEANS ESTABLISHING A CONSTANT ROTATABLE DRIVING CONNECTION BETWEEN THE MOTOR AND THE TOOL TO CONTINUOUSLY LOAD THE MOTOR, A SOURCE OF FLUID UNDER PRESSURE, PASSAGE MEANS CONNECTING SAID SOURCE TO THE MOTOR INCLUDING INLET AND OUTLET CONDUITS CONNECTED TO THE MOTOR FOR DRIVING THEREOF AND A BY-PASS PASSAGE, VALVE MEANS IN SAID BY-PASS PASSAGE BIASED TO AN OPEN CONDITION FOR ESTABLISHING UNRESTRICTED FLOW OF FLUID BETWEEN THE INLET AND OUTLET CONDUITS BY-PASSING THE MOTOR, SELECTIVELY ACTUATED TRIGGER MEANS FOR CLOSING SAID VALVE MEANS TO ESTABLISH A PRESSURE DIFFERENTIAL BETWEEN SAID CONDUITS, AND COAST PREVENTING MEANS RESPONSIVE TO OPENING OF THE VALVE MEANS FOR INSTANTANEOUSLY REDUCING SAID PRESSURE DIFFERENTIAL BETWEEN THE CONDUITS TO STOP DRIVE OF THE MOTOR BY THE TOOL.