Mast and carriage for a lift truck

Claim 1

A mast assembly for a truck or the like, comprising: first and second upright laterally spaced channel members each defining a base portion and forward and rearward parallel edge flange portion extending from said base portion and generally perpendicular thereto, with the flange portions of each channel member disposed toward the other channel member; first and second interconnected elongated members positioned inwardly of the first and second channel members respectively and movable therealong, the first elongated member defining a base portion and an edge flange portion extending from said base portion and generally perpendicular thereto, and disposed toward the first channel member and between the forward and rearward flange portions of the first channel member and adjacent the rearward flange portion thereof, the second elongated member defining a base portion and an edge flange portion disposed toward the second channel member and between the forward and rearward flange portions of the second channel member and adjacent the rearward flange portion thereof; first and second bottom rollers mounted to the lower ends of the first and second elongated members respectively, the edge flange portions of the first and second elongated members defining cutout portions through which portions of the first and second bottom rollers respectively extend, with the first bottom roller positioned between the forward and rearward flange portions of the first channel member, with the rolling portions of the first bottom roller adjacent the forward and rearward flange portions of the first channel member, and further with the second bottom roller positioned between the forward and rearward flange portions of the second channel member, with the rolling portions of the second bottom roller adjacent the forward and rearward flange portions of the second channel member; first and second top rollers mounted to the upper ends of the first and second channel members respectively, with the forward flange portions of the first and second channel members defining cutout portions through which portions of the first and second top rollers respectively extend, with the rolling portion of the first top roller adjacent the edge flange portion of the first elongated member, and with the rolling portion of the second top roller adjacent the edge flange portion of the second elongated member; a fork carriage comprising a frame and a pair of forwardly extending arms; first and second rollers mounted to the fork carriage frame and rollingly associated with the first elongated member, with the axis of the second roller being below the axis of the first roller; third and fourth rollers mounted to the fork carriage frame and rollingly associated with the second elongated member, with the axis of the fourth roller being below the axis of the third roller, allowing movement of the fork carriage along the elongated members upwardly and downwardly, meanwhile providing positive forward-and-rearward location of the fork carriage relative to the first and second elongated members; a fifth roller mounted to fork carriage frame and positioned with its axis below the axis of the first roller and above the axis of the second roller; and, a sixth roller mounted to the fork carriage frame and positioned with its axis below the axis of the third roller and above the axis of the fourth roller, the fifth and sixth rollers being in contact with the rear portions of the first and second elongated member respectively inwardly of the first and second elongated members respectively, and a reinforcing member interconnecting the first and second elongated members rearwardly thereof, the fifth and sixth rollers passing closely adjacent thereto to minimize misalignment of said elongated members, to provide positive lateral location of the fork carriage relative to the first and second elongated members.