Electrical indicator device

Claim 1

A COMPACT, SHOCK-RESISTANT, ELECTRIC CURRENT-RESPONSIVE INDICATOR DEVICE FOR CONNECTION TO A D.C. CIRCUIT TO INDICATE CONDITIONS OF ENERGIZATION AND DEENERGIZATION THEREOF COMPRISING, IN COMBINATION: (A) A RIGHT-ANGLED BASE BLOCK OF INSULATING MATERIAL, SAID BLOCK HAVING AN OPENING AT ONE SIDE THEREOF, (B) A STATIONARY SHAFT CARRIED AT SOLELY ONE END BY THE BASE BLOCK, SAID SHAFT BEING DISPOSED IN THE OPENING OF THE BLOCK AND PROJECTING FROM THE SAID SIDE THEREOF TO HAVE A FREE END, (C) AN INDICATOR DRUM HAVING INDICIA, SAID DRUM BEING TURNABLY CARRIED BY THE SHAFT, ONE END OF THE DRUM BEING ADJACENT THE SAID SIDE OF THE BASE BLOCK, (D) A PERMANENT MAGNET AFFIXED TO THE DRUM AT THE SAID ONE END THEREOF, TO TURN THEREWITH, SAID MAGNET BEING CLOSELY ADJACENT THE PORTION OF THE BLOCK WHICH SUPPORTS THE SHAFT AND BEING REMOTE FROM THE FREE END OF THE SHAFT, THEREBY TO MINIMIZE LATERAL DEFLECTION OF THE SHAFT BY THE MAGNET, (E) AN ELECTROMAGNET HAVING POLES OF MAGNETIC MATERIAL, SAID ELECTROMAGNET BEING CARRIED BY THE BASE BLOCK WITH AT LEAST ONE POLE PORTION LOCATED IN THE IMMEDIATE FIELD OF INFLUENCE OF THE PERMANENT MAGNET, THE MAGNETIC ATTRACTION BY THE LATTER TENDING TO HOLD THE DRUM IN AN "OFF," DEENERGIZATION-INDICATING POSITION WHEN THE ELECTROMAGNET IS UNENERGIZED, AND D.C. ENERGIZATION OF THE ELECTROMAGNET IN ONE SENSE EFFECTING A REPULSION OF THE PERMANENT MAGNET AND SHIFTING OF THE SAME AND THE DRUM TO ANOTHER AND "ON" ROTATIVE POSITION INDICATING ENERGIZATION OF THE ELECTROMAGNET, (F) THE POLES OF THE ELECTROMAGNET COMPRISING L-SHAPED PLATES DISPOSED RESPECTIVELY AGAINST OPPOSITE PARALLEL SIDES OF THE BASE BLOCK LOCATED AT RIGHT ANGLES TO THE SAID OTHER SIDE OF THE BLOCK, (G) SAID POLE PLATES HAVING PAIRS OF OPPOSITE LEGS, ONE PAIR OF LEGS BEING EXTENDED CLEAR OF THE BLOCK AND THE OTHER PAIR ENGAGING THE BLOCK ALONG THEIR LENGTHS, ONE LEG OF SAID OTHER PAIR CONSTITUTING THE SAID POLE PORTION LOCATED IN THE FIELD OF THE PERMANENT MAGNET, (H) SAID ELECTROMAGNET INCLUDING A COIL DISPOSED BETWEEN AND MAGNETIZING THE SAID ONE PAIR OF LEGS OF THE POLE PLATES, SAID COIL BEING DISPOSED BROADSIDE TO OTHE INDICATOR DRUM.