Variable speed control for knitting machine

Claim 1

SPEED CONTROL APPARATUS FOR CONTROLLING THE OPERATING SPEED OF A WORK UTILITY WHICH IS IS DESIRED TO DRIVE AN ANY OF A PLURALITY OF SELECTABLE DIFFERENT SPEEDS FROM A CONSTANT SPEED PRIMARY DRIVE SOURCE, COMPRISING IN COMBINATION, A POWER TRANSMISSION HAVING A ROTARY INPUT DRIVE SHAFT CONNECTABLE TO A CONSTANT SPEED DRIVE SOURCE, A ROTARY OUTPUT DRIVE SHAFT CONNECTABLE TO THE WORK UTILITY TO DRIVE THE LATTER, AND AN ELECTRICALLY ACTUATABLE CLUTCH EFFECTIVE WHEN ACTUATED FOR COUPLING THE ROTARY OUTPUT DRIVE-SHAFT TO THE ROTARY INPUT DRIVESHAFT, SAID SPEED CONTROL APPARATUS COMPRISING IN COMBINATION, SPEED SELECTION ELECTRIC SWITCH MEANS FOR SELECTING ANY ONE OF A PLURALITY OF DIFFERENT SPEEDS AT WHICH IT IS DESIRED TO OPERATE A WORK UTILITY, AND SPEED SENSING ELECTRIC SWITCH MEANS CONNECTED IN ELECTRIC CIRCUIT WITH THE ELECTRICALLY ACTUATABLE CLUTCH AND A SOURCE OF ELECTRIC POWER, SAID SPEED SENSING SWITCH MEANS BEING OPERATIVELY COUPLED TO THE POWER TRANSMISSION ROTARY OUTPUT DRIVE SHAFT FOR SIMULTANEOUS ROTATION THEREWITH AND RESPONSIVE TO DEPARTURE OF THE OUTPUT DRIVE SHAFT ROTATIONAL SPEED FROM THE SELECTED DESIRED SPEED TO ALTER THE ELECTRIC CIRCUIT CONDITIONS TO THEREBY ACTUATE SAID CLUTCH MEANS WHENEVER THE OUTPUT DRIVE SHAFT ROTATIONAL SPEED DROPS BELOW SAID DESIRED SPEED AND TO DEACTUATE THE CLUTCH MEANS WHENEVER THE OUTPUT DRIVE SHAFT ROTATIONAL SPEED RISES ABOVE THE SELECTED DESIRED SPEED.