Electric drives

Claim 1

AN ELECTRIC DRIVE COMPRISING A MOTOR HAVING A STUB SHAFT, AN ELECTRIC SLIP COUPLING HAVING A DRIVING INDUCTOR MEMBER CARRIED ON A SLEEVE FITTED TO SAID STUB SHAFT AND HAVING A DRIVEN POLAR FIELD MEMBER CARRIED ON AND SURROUNDING SAID SLEEVE, A FIELD COIL IN THE FIELD MEMBER, AN ELECTRICAL SUPPORT ON THE MOTOR FOR AXIALLY DIRECTED FIRST, SECOND AND THIRD BRUSHES, AND ELECTRICAL SPEED CONTROL FOR VARIABLY ENERGIZING SAID COIL, A SOURCE OF ELECTRICAL POWER HAVING FIRST AND SECOND TERMINALS, FIRST AND SECOND RADIALLY FLAT CONDUCTIVE SLIP RINGS CARRIED BY SAID FIELD MEMBER TO ENGAGE SAID AXIALLY DIRECTED BRUSHES AND RESPECTIVELY ELECTRICALLY CONNECTED ACROSS SAID FIELD COIL, EACH OF SAID SLIP RINGS HAVING A CONTINUOUS PERIPHERAL PORTION, SAID SECOND SLIP RING ALSO HAVING RADIALLY DIRECTED MARGINAL INTERRUPTING MEANS FORMED BY SPACED MARGINAL TEETH, SAID FIRST AND SECOND STATIONARY BRUSHES CONTACTING THE CONTINUOUS PERIPHERAL PORTIONS OF SAID FIRST AND SECOND SLIP RINGS, SAID SECOND BRUSH CONNECTED WITH SAID FIRST TERMINAL, AND SAID THIRD STATIONARY BRUSH CONNECTED TO AN INPUT OF SAID SPEED CONTROL AND CONTACTING SAID CIRCUIT INTERRUPTING MEANS INTERMITTENTLY TO ELECTRICALLY INTERCONNECT SAID SECOND SLIP RING AND SAID THIRD BRUSH TO SUPPLY AN INTERMITTENT CONTROL SIGNAL TO SAID SPEED CONTROL INPUT, SAID SECOND POWER SUPPLY TERMINAL BEING INTERCONNECTED TO SAID SPEED CONTROL, SAID SPEED CONTROL HAVING AN OUTPUT CONNECTED TO SAID FIRST BRUSH WHEREBY THE FIELD COIL IS VARIABLY ENERGIZED BY SAID CONTROL TO MAINTAIN A SUBSTANTIALLY CONSTANT ANGULAR VELOCITY OF SAID DRIVEN MEMBER.