Magnetic pressure indicator

Claim 1

A DIFFERENTIAL PRESSURE INDICATOR FOR USE IN A FLUID PRESSURE SYSTEM HAVING A SOURCE OF HIGH PRESSURE AND A SOURCE OF LOW PRESSURE COMPRISING: (A) A HOUSING; (B) A PARTITION MEANS DIVIDING SAID HOUSING INTO TWO CHAMBERS; (C) ONE OF SAID CHAMBERS DEFINING A FLUID PRESSURE CHAMBER AND THE OTHER OF SAID CHAMBERS ADAPTED TO HOUSE AN INDICATING MEANS; (D) A MOVABLE PISTON MEANS DISPOSED WITHIN SAID FLUID PRESSURE CHAMBER FOR DIVIDING SAID PRESSURE CHAMBER INTO A LOW PRESSURE COMPARTMENT ON ONE SIDE OF SAID PISTON MEANS AND A HIGH PRESSURE COMPARTMENT ON THE OTHER SIDE OF SAID PISTON MEANS; (E) SAID PISTON MEANS INCLUDING A MAGNETIC ELEMENT DISPOSED OPPOSITE SAID PARTITION AND MOUNTED FOR MOVEMENT WITH SAID PISTON; (F) MEANS FOR NORMALLY URGING SAID PISTON MEANS TOWARD CLOSE PROXIMITY TO SAID PARTITION MEANS WHEREBY SAID MAGNETIC ELEMENT IS NORMALLY PRESENTED ADJACENT OF SAID PARTITION; (G) A FIXED MAGNET MOUNTED IN SPACED RELATIONSHIP WITH SAID PARTITION IN SAID OTHER CHAMBER, SAID FIXED MAGNET FACING SAID PARTITION; (H) AN ARMATURE DISPOSED BETWEEN SAID FIXED MAGNET AND PARTITION FOR MOVEMENT THEREBETWEEN; (I) SAID ARMATURE HAVING A STEM PROJECTING UPWARDLY THROUGH AN OPENING FORMED IN SAID FIXED MAGNET; AN ENLARGED HEAD AT THE TOP OF THE STEM; (J) SAID ARMATURE BEING NORMALLY ATTRACTED TO SAID MOVABLE MAGNET, BUT SUBJECT AT ALL TIMES TO THE MAGNETIC FIELD OF SAID FIXED MAGNET; (K) AN INDICATING BUTTON MOUNTED OVER THE END OF SAID STEM FOR MOVEMENT BETWEEN AN EXTENDED INDICATING POSITION AND A RETRACTED NONINDICATING POSITION; THE BUTTON HAVING AN INTERIOR ANNULAR FLANGE DEFINING A SHOULDER; (1) A SPRING MEANS NORMALLY BIASING SAID BUTTON TOWARD ITS EXTENDED INDICATING POSITION; (M) SLEEVE MEANS DISPOSED BETWEEN THE BUTTON AND THE ARMATURE, THE SLEEVE MEANS CONTACTING A PLURALITY OF BALL MEANS, THE BALL MEANS BEING MAINTAINED IN CONTACT WITH THE ANNULAR FLANGE BY MEANS OF THE ENLARGED HEAD MOVEMENT OF THE ARMATURE UPWARDLY PERMITTING THE BALL MEANS TO DISENGAGE THE ANNULAR FLANGE AND CONTACT THE STEM OF SAID ARMATURE; (N) AND MEANS FOR LIMITING THE MOVEMENT OF SAID BUTTON IN THE EXTENDED INDICATING POSITION THEREOF.