Patent ID: 7143970

Claim:
A jaw crusher for crushing hard materials, comprising: (a) a frame; (b) a stationary jaw connected to the frame; (c) a movable jaw positioned spaced in an opposed relationship with the stationary jaw for the receipt of hard materials to be crushed between the jaws, the movable jaw pivotally connected to the frame for pivotal movement about a movable jaw shaft axis with respect to the stationary jaw; (d) a lever pivotally connected to the frame for pivotal movement about a lever shaft axis, the lever comprising a first extension having a part communicating with the lever shaft and a part communicating with a force transfer device which in turn communicates with the lower back part of the movable jaw to move the movable jaw, and a second extension having a part communicating with the lever shaft and a part communicating with a powered reciprocating drive; (e) the powered reciprocating drive communicating with the end part of the second extension of the lever to cause cyclic reciprocating movement of the lever about the lever shaft axis for the cyclic supply of crushing power; (f) the force transfer device delivering the movement of the first extension of the lever to the movable jaw, the lever shaft axis being above the force transfer device; and (g) a biasing device eliminating the unnecessary clearance between the moving parts of the crusher during crushing operation, wherein the first extension of the lever includes a crushed rock size adjusting device, and wherein the crushed rock size adjusting device comprises: a rectangular paralleled piped housing which has two rectangular openings, one of which is toward the movable jaw and the other of which is on a rear part of an upper face of the housing for the addition or retrieval of adjusting plates and an end wall which has a hydraulic jack access hole; an adjusting block which is inserted into the housing through the rectangular opening toward the movable jaw for movement and has a toggle seat or a roller seat on the face toward the movable jaw; the adjusting plates; and hydraulic jack chamber which is attached behind the end wall of the housing.