Dump truck bodies

Claim 1

IN A DUMP TRUCK BODY, IN COMBINATION, A FRONT WALL, A MOVABLE TAIL-GATE, AND MEANS FOR MOVING SAID FRONT WALL FORWARDLY AND REARWARDLY BETWEEN THE RIGID SIDE WALLS OF SAID BODY IN ITS PLANE TO PUSH A LOAD CONTAINED BETWEEN SAID FRONT WALL AND TAIL-GATE OFF THE REAR END OF SAID BODY DURING THE REARWARD MOVEMENT OF SAID FRONT WALL, SAID FRONT WALL CONSISTING OF AT LEAST TWO SECTIONAL PANELS IN OVERLAPPING RELATIONSHIP, AND SPRING-MEANS COACTING BETWEEN SAID PANELS NORMALLY TO BIAS SAID PANELS OUTWARDLY SO THAT THE OUTER SIDE EDGES OF SAID FRONT WALL ARE CONTIGUOUS TO SAID SIDE WALLS, SAID PANELS MOVING IN THE PLANE OF SAID FRONT WALL UPON ENCOUNTERING DEFORMITIES IN SAID SIDE WALLS, SAID SPRING MEANS INCLUDING HORIZONTALLY DISPOSED CYLINDRICAL COIL SPRING, HOUSING FOR THE SAME, SAID HOUSINGS BEING SECURED UPON THE ANTERIOR SURFACES OF SAID PANELS, AND ABUTMENTS ALSO SECURED TO THE ANTERIOR SURFACE SAID PANELS, PART OF EACH OF SAID SPRINGS EXTENDING BETWEEN ONE OF SAID HOUSINGS AND ONE OF SAID ABUTMENTS.