Apparatus for measuring levels of materials in containers

Claim 1

APPARATUS FOR DETERMINING THE SURFACE LEVEL OF FLOWABLE MATERIAL IN A CONTAINER COMPRISING A LEVEL SENSING WEIGHT MEMBER ADAPTED TO BE BROUGHT INTO CONTACT WITH SAID SURFACE, A CABLE FOR SUSPENDING SAID WEIGHT MEMBER WITHIN SAID CONTAINER FOR VERTICAL MOVEMENT RELATIVE TO SAID SURFACE, A ROTATABLE DRUM ON WHICH SAID CABLE IS WOUND AND ANCHORED, A REVERSIBLE MOTOR COUPLED TO SAID DRUM FOR ROTATING SAID DRUM TO DRAW IN AND PAY OUT SAID SAID CABLE FOR RAISING AND LOWERING SAID WEIGHT MEMBER RELATIVE TO SAID SURFACE, A ROTATABLE PULLEY OVER WHICH THE CABLE IS TRAINED OVERLYING SAID CONTAINER AND SUPPORTING SAID WEIGHT MEMBER AND A DEPENDING CABLE PORTION IN SUSPENDED RELATION THEREFROM, GUIDE MEANS FOR SAID PULLEY RESTRAINING THE PULLEY FOR MOVEMENT ALONG A RECTILINEAR PATH INCLINED TO A VERTICAL AXIS, SPRING MEANS CONNECTED TO SAID PULLEY AND EXTENDING IN OPPOSITE DIRECTIONS THEREFROM ALONG SAID PATH TO STATIONARY ANCHORS RESILIENTLY SUPPORTING SAID PULLEY ALONG SAID PATH AT POSITIONS WHICH VARY IN RELATION TO VARIATIONS IN THE TENSION EXERTED ON THE CABLE BY SAID WEIGHT MEMBER, A PAIR OF STATIONARY SWITCH MEMBERS HAVING SWITCH ARMS DISPOSED TO BE ACTUATED BY SAID PULLEY UPON MOVEMENT OF THE PULLEY ALONG SAID PATH RESPONSIVE TO INCREASE AND DECREASE OF CABLE TENSION FROM A SELECTED CABLE TENSION VALUE, MEANS RESPONSIVE TO ACTUATION OF SAID SWITCH MEANS FOR REVERSING THE DIRECTION OF DRIVE OF SAID REVERSIBLE MOTOR, AND INDICATOR MEANS CALIBRATED IN CONTAINER LEVELS CONTINUOUSLY RESPONSIVE TO THE ANGULAR POSITION OF SAID DRUM TO INDICATE THE HEIGHT OF FILL IN SAID CONTAINER.