Device for positioning a movable body

Claim 1

APPARATUS FOR POSITIONING A MOVABLE BODY ADAPTED FOR MOVING AT RELATIVELY HIGH SPEED ALONG A PREESTABLISHED TRAJECTORY, SAID APPARATUS COMPRISING A RULE EXTENDING ADJACENT, SAID TRAJECTORY, A PLURALITY OF MARKING MEANS ON SAID RULE EXTENDING FROM A REFERENCE LOCATION IN THE DIRECTION OF MOVEMENT OF THE MOVABLE BODY AT REGULARLY SPACED INTERVALS, MEANS FOR SELECTIVELY ENERGIZING THE MARKING MEANS ONE BY ONE TO MOVE THE SAME FROM AN INOPERATIVE TO AN OPERATIVE POSITION, SAID RULE BEING PROVIDED WITH GRADUATIONS OVER A LENGTH CORRESPONDING TO THE SPACING BETWEEN ADJACENT MARKING MEANS, THE GRADUATIONS EXTENDING FROM THE REFERENCE LOCATION IN A DIRECTION AWAY FROM THE DIRECTION OF TRAVEL OF THE BODY, MEANS FOR RELATIVELY MOVING THE RULE PARALLEL TO THE TRAJECTORY BY A DISTANCE LESS THAN THE SPACING BETWEEN ADJACENT MARKING MEANS AND CORRESPONDING TO THE FRACTIONAL PROPORTION OF SAID SPACING EXCEEDING THE NUMBER OF EQUAL SPACINGS THAT IT IS DESIRED TO MOVE THE MOVABLE BODY, AND A READING DEVICE SECURED TO THE MOVABLE BODY FOR MOVEMENT THEREWITH, SAID READING DEVICE INCLUDING FIRST AND SECOND SENSING MEANS WHICH ARE SPACED IN THE DIRECTION OF MOVEMENT OF THE BODY TO SENSE THE PARTICULAR MARKING MEANS WHICH IS IN OPERATIVE POSITION, THE FIRST SENSING MEANS CAUSING THE MOVING BODY TO SLOW DOWN WHEN IT SENSES THE OPERATIVE MARKING MEANS, THE SECOND SENSING MEANS CAUSING THE MOVING BODY TO STOP IN ALIGNMENT WITH SAID OPERATIVE MARKING MEANS WHEN IT SENSES THE SAME.