Householder's mailbox pick-up signal

Claim 1

IN A MAILBOX HAVING AN OPEN-ENDED STATIONARY BODY, A SWINGABLE DOOR HINGED AT ITS LOWER EDGE TO SAID BODY AND ADAPTED TO COVER THE OPEN END OF SAID BODY, SAID DOOR HAVING A VERTICAL FLANGE EXTENDING ALONG OND SIDE THEREOF, (A) A BRACKET FRICTIONALLY ENGAGEABLE WITH SAID FLANGE HAVING FIRST AND SECOND ARCUATELY SPACED ABUTMENTS RESIDING TO EITHER SIDE OF A VERTICAL PLANE WHEN SAID BRACKET IS ENGAGED WITH SAID FLANGE AND SAID DOOR IS CLOSED, (B) A SIGNAL ARM HAVING A LATERAL PROJECTION AT ONE END, (C) MEANS PIVOTALLY CONNECTING SAID SIGNAL ARM AT A POINT INTERMEDIATE ITS ENDS SO THAT THE END OPPOSITE SAID ONE END IS LARGER AND HEAVIER THAN SAID ONE END, (D) WHEREBY WHEN SAID SIGNAL ARM HAS BEEN MANUALLY ROTATED TO CAUSE ENGAGEMENT OF SAID PROJECTION WITH SAID FIRST ABUTMENT WITH SAID DOOR CLOSED IT WILL REMAIN IN ONE TILTED POSITION, SUBSEQUENT OPENING OF SAID DOOR CAUSING AUTOMATIC SHIFTING OF SAID ARM TO CAUSE ENGAGEMENT OF SAID PROJECTION WITH SAID SECOND ABUTMENT WITH THE RESULT THAT SAID SIGNAL ARM WILL REMAIN IN A SECOND TILTED POSITION UNTIL AGAIN MANUALLY ROTATED TO SAID ONE TILTED POSITION.