3.12.8 Adjusting mechanism. An adjusting mechanism of the wedge-and-screw or shim
type shall be provided which will permit adjustment of the opening between the jaws. The
adjusting mechanism shall be cast steel or fabricated steel plate, and shall be reinforced to
withstand crushing of maximum size material. All contact surfaces of the adjusting mechanism
shall be machined to insure uniform distribution of the load on the respective parts of the
crushing component frame. A stop shall be provided to prevent adjustment to actual contact of
the jaws during any part of the crushing cycle.
3.12.9 Jaw setting. The jaw setting shall be measured along or parallel to the longitudinal
axis of the jaw crusher on a horizontal plane. Measurement shall be of the greatest opening in
the minimum discharge position of the jaws in the crushing cycle, normally between the ridge of
one jaw and the valley of the other. Variation between any two measurements for any jaw
setting shall be not greater than 1/4-inch. Jaw settings shall be provided which can produce the
materials specified in 3.12.
3.13 Conveyors. The crusher shall be equipped with an end-delivery conveyor which shall
receive materials from the grizzly chutes and jaw crushing component in a receiving hopper.
The conveyor shall have a belt 30 inches wide with a belt speed not less than 300 feet per
minute. The conveyor shall have not less than 10 feet of ground clearance measured on the
vertical from the centerline of the head pulley.
3.13.1 Frame. The conveyor frame shall be of rigid construction, shall support all other
components of the conveyor not supported directly by the chassis, and shall withstand all static
and dynamic loads imposed by other components when operating with a loading of 50 pounds
per lineal foot of belt or when traveling. When hinged sections of frame are provided, stiffeners,
braces, or other means shall be provided to maintain frame rigidity during operation and travel.
3.13.2 Head pulley. The head pulley shall be the drive pulley, shall be of steel construction
not less than 32 inches wide, not less than 14 inches in diameter, and shall be crowned and
lagged. The crown shall taper 1/8-inchper-foot to the center of the pulley. The outside surface
of the pulley shall be concentric with the shaft within a total indicator reading of 0.060 inch,
except a total indicator reading of 0.090 inch is permissible in an area immediately adjacent to a
3.13.3 Tail pulley. The tail pulley shall be of steel construction not less than 32 inches wide,
and not less than 12 inches in diameter, shall be the wing or self-cleaning type, and shall be
crowned. The crown shall taper 1/8-inch-per-foot to the center of the pulley. The outside
surface of the pulley shall be concentric with the shaft within a total indicator reading of