Vertical shaft impact crusher having a vertically adjustable feed tube

Abstract

A vertical shaft impact crusher has an vertically adjustable feed tube disposed within a throat between a feed hopper of the crusher and the crusher lid of the housing. The feed tube may be adjusted in predetermined discrete increments to within a predetermined distance above an impeller table of the crusher within the housing of the crusher and without removing the hopper of the crusher during such adjustment. The adjustment is achieved by rotating an adjustment ring disposed at an interface between a hopper portion and a lid portion of the throat between the hopper and the lid. The adjustment ring may be held between to adjacent throat flanges to rotate circumferentially about a vertical crusher axis. The feed tube is a two-piece tube which includes an upper, re-usable portion and a lower expendable portion. The feed tube is held within a carrier tube which includes circumferentially spaced adjustment steps. The adjustment ring includes radially inward extending lugs which engage respective steps to support the feed tube at a height determined by the vertical position of the respective steps with respect to the carrier tube. As the ring is rotated in one predetermined direction, the lugs move off one set of steps and the tube drops until the lugs engage an adjacent set of steps of the carrier tube. A circumferential movement of the adjusting ring in the direction opposite to the adjustment rotation of the ring cuases the lugs to engage an undercut disposed at an inner end of each adjustment step.