3.13.9 Driving mechanism. The driving mechanism shall consist of a reducing gear
arrangement powered by a 10-hp electric motor (see 3.8.2) through a multiple V-belt drive. The
reducing gear shall be totally enclosed and operated in an oil bath. Bearings shall be antifriction
type and shall conform to FF-B-171, FF-B-185, or FF-B-187, as applicable. Bearings
conforming to FF-B-171 may be retained on the shaft by a bearing-retainer plate and shims
between the retainer plate and housing to provide endwise adjustment.
126.96.36.199 Holdback device. An automatic holdback device of the overrunning, clutch type
shall be furnished to prevent slippage or reversal of flow when the motor stops.
3.13.10 Belt cleaners. A weight-loaded or spring-loaded, replaceable, single-rubber-blade
belt scraper shall be mounted at the drive (head) end pulley. The scraper shall cause the scraped
material to fall forward and toward the main discharge. The blade shall be neoprene rubber not
less than 1 inch thick and shall be split in the center to match the contour of the crown. A
weight-loaded or spring-loaded, V-shaped, rubber-blade scraper shall be mounted inside the
return run of the belt at the foot (tail) end pulley. The blades shall be neoprene rubber and shall
be not less than 3/8-inch thick. The scrapers shall exert uniform pressure across the full width of
3.13.11 Receiving hopper. The receiving hopper shall be mounted at the lower end of the
conveyor frame, shall be removable, shall be of the skirt board type, and shall be three-sided.
The hopper shall have sloping sides to prevent spillage of material. The hopper shall extend not
less than 12 inches beyond the discharge of the crusher jaws toward the drive end of the
conveyor. The space between the three sides of the hopper and the conveyor belt shall be
provided with adjustable and replaceable rubber flashing mounted under the hopper plates. The
hopper plates shall be of steel conforming to ASTM A242 and shall be not less than 0.187 inch
in nominal thickness.
3.13.12 Side delivery conveyor. When a side delivery conveyor is furnished (see 3.11), it
shall be driven by a 5-hp motor as specified in 3.8.2. Means shall be provided for delivery of
material to either side of the jaw crusher. A reversing switch may be used to reverse the
direction of the discharge, and a warning plate shall be provided to guard against reversing while
the motor is running. The discharge ground clearance shall be of sufficient height to permit
delivery of material into the receiving hopper of a portable conveyor.
3.14 Trailer components. The physical characteristics of the crusher trailer in operational
condition for processing rock, with dolly, all components, attachments, accessories, equipment,
tools; and fuel, oil, and coolant reservoirs filled to rated capacity shall be as specified below. All
measurements shall be made with the crusher on level ground, and the inflation pressure of the
tires shall be as recommended by the tire manufacturer for operation at 30 mph highway speeds.
Axle loads shall be measured at the ground under the tires. Published component and vehicular