Means for controlling the movement of pallets on a sintering machine

Claim 1

A PALLET MOVING AND RETARDING MEANS FOR A DWIGHTLLOYD TYPE OF HORIZONTAL SINTERING MACHINE IN WHICH A TRAIN OF MATERIAL CARRYING PALLETS ARE MOVED ALONG A HORIZONTAL TRACKWAY IN CONTACT WITH EACH OTHER AND THE PALLETS CONSTITUTE A CONTINUOUS TRAIN AROUND A CURVED RACEWAY AND ONTO A LOWER REACH OF TRACKWAY AND ARE THEN MOVED UPWARDLY AROUND A CURVED RACEWAY TO THE FEED END OF THE HORIZONTAL PORTION; AND INCLUDING (A) MAIN DRIVE SPROCKET WHEEL MEANS FOR RAISING THE PALLETS WHILE IN CONTACT UPWARDLY AROUND THE CURVED RACEWAY AND FOR PUSHING THE TRAIN ALONG THE UPPER HORIZONTAL RACEWAY; (B) THE LENGTH OF THE TRAIN OF CONTACTING PALLETS BEING LESS THAN THE LENGTH OF THE TRACKWAY WHEREBY AN EXPANSION GAP MAY BE LEFT BETWEEN SUCCESSIVE PALLETS AS THEY PASS A GIVEN POINT; (C) A RETARDER SPROCKET ADAPTED TO ENGAGE SUCCESSIVE PALLETS AND RESIST MOVEMENT OF THE PALLETS APPROACHING THE GAP; (D) ELECTRIC DRIVING AND RETARDER MOTORS FOR RESPECTIVELY DRIVING THE MAIN DRIVE SPROCKET WHEEL MEANS AND THE RETARDER SPROCKET AT PREDETERMINED SPEEDS, THE RETARDER SPROCKET BEING NORMALLY DRIVEN AT A SLIGHTLY SLOWER SPEED BY ITS MOTOR, BUT AT THE SAME TIME BEING NORMALLY FORCED BY MOVEMENT OF THE PALLETS TO MAINTAIN THE SPEED CORRESPONDING TO THE MOVEMENT OF THE MAIN DRIVE SPROCKET WHEEL MEANS WHEREBY A RESISTING HOLD-BACK PRESSURE OF A SMALL FRACTION OF THE DRIVING POWER OF THE MAIN DRIVE SPROCKET WHEEL MEANS IS MAINTAINED UP TO A CONTROLLED LIMIT; (E) TACHOMETER GENERATORS POSITIVELY DRIVEN WITH EACH OF SAID DRIVING AND RETARDER MOTORS; AND (F) MEANS TO CONTROL THE VOLTAGE AND, THEREFORE, THE SPEED OF SAID RETARDER MOTOR AS A FUNCTION OF THE SPEED OF THE MAIN DRIVE SPROCKET WHEEL MEANS, SAID CONTROL MEANS COMPRISING A BOOSTER GENERATOR HAVING A VOLTAGE OUTPUT VARYING AS A FUNCTION OF ANY SPEED DIFFERENTIAL BETWEEN SAID TACHOMETER GENERATORS, SAID RETARDER MOTOR BEING RESPONSIVE TO THE VOLTAGE OUTPUT OF SAID BOOSTER GENERATOR TO CAUSE IMMEDIATE SYNCHRONIZING OF THE RETARDER SPROCKET WITH THE SPEED OF THE MAIN DRIVE SPROCKET WHEEL MEANS CONSEQUENT UPON A CHANGE OF SPEED OF THE MAIN DRIVE SPROCKET WHEEL MEANS SENSED BY SAID TACHOMETER GENERATORS.