member 24 such that pivoting movement of the central pivot member in an upward direction brings the rearward edges 31 33 of the outer walls and the forward edges 105 107 of the upper pivot limiting member 102 into abutment with each other thus blocking further pivot movement of the central pivot member the forward edges 105 107 of the pivot limiting member 102 thus present a surface against which the central pivot member 24 abuts when the central pivot member is in an operational dozing position in the most preferred embodiment of the upper pivot limiting member 102 at least one pivot locking tab 108 is provided for locking the central pivot member 24 against pivot movement with respect to the support structure 80 and thereby locking the position of the articulated dozer blade 12 with respect to the vehicle to which the support structure is attached preferably a pair of pivot locking tabs 108 109 are employed and are mounted so as to extend forwardly from the upper pivot limiting member 102 such that the tabs 108 109 embrace a portion of the central pivot member 24 and ideally a tab is mounted to the outer surface of each of the lateral.