Patent ID: 7431553

Claim:
A loader work machine comprising: a vehicle body; a working implement having booms and boom cylinders; and mounting frame units for attaching said working implement to a front portion of said vehicle body, each of said mounting frame units including: a mounting plate fixed to said vehicle body; a support base projecting laterally outward from said mounting plate; a side frame for pivotally supporting proximal ends of one of said booms and one of said boom cylinders, said side frame including right and left side plates and a connecting member for interconnecting said right and left side plates, said right and left side plates having a first pin extending therebetween, and each of said right and left side plates having a first hole defined therein; and a main frame for detachably connecting and supporting said side frame, said main frame being formed as a one-piece plate insertible between said right and left side plates, said main frame defining a receiving member recessed and opened to be engageable with said first pin, said main frame further defining a second hole alignable with the first hole of each of said right and left side plates; wherein a first boss is provided along said receiving member and a second boss is provided around said second hole, said first and second bosses protruding larger than a right/left width of said one-piece plate of the main frame toward said right and left side plates of the side frame to assist connection of said main frame to said side frame; said main frame is directly connected with and supported by said support base to stand erect from said support base; and said main frame formed as a one-piece plate has, on at least one of a right side and a left side thereof, a first vertical rib extending from said first boss to said support base and a second vertical rib extending from said second boss to said support base, said first and second vertical ribs protruding laterally from the at least one side of said main frame formed as a one-piece plate.