Quick detachable backfill blade for trencher

Claim 1

A BLADE ATTACHMENT FOR AN EARTH WORKING VEHICLE HAVING A CHASSIS FRAME AND COMPRISING A HORIZONTAL SUPPORT ADAPTED TO BE MOUNTED UPON SAID CHASSIS FRAME AND EXTENDING TRANSVERSELY OF THE VEHICLE WHILE IN TRAVEL, AN EARTH MOVING BLADE, MOUNTING MEANS RELEASABLY CONNECTING SAID BLADE TO SAID SUPPORT, SAID SUPPORT HAVING A VERTICAL WALL AND A GENERALLY HORIZONTAL WALL, SAID MOUNTING MEANS COMPRISING A HANGER BRACKET SECURED TO THE REAR FACE OF SAID BLADE AND HAVING A DOWNWARDLY OPEN POCKET THEREIN SAID MOUNTING MEANS FURTHER INCLUDING A HORIZONTAL REARWARDLY EXTENDING PLATE ON THE REAR FACE OF SAID BLADE, THE UPPER SURFACE OF SAID PLATE HAVING AN UNINTERRUPTED, GENERALLY HORIZONTAL SURFACE THROUGHOUT ITS ENTIRETY, THE UPPER EDGE OF SAID VERTICAL WALL BEING RECEIVED IN SAID POCKET WHEREBY SAID MOUNTING MEANS AND SAID BLADE ARE SUPPORTED SOLELY BY GRAVITY ON SAID VERTICAL WALL, SAID PLATE UNDERLYING SAID HORIZONTAL WALL, AND PIN MEANS RELEASABLY EXTENDING THROUGH REGISTERING APERTURES IN SAID PLATE SAID HORIZONTAL WALL.