Mount the crusher in a level position to the back of the Sweco dozer. The hopper must be in place before use.
Operate one auxiliary hookup at a time when the crusher is attached to the Sweco. All auxiliary hookups share the same hydraulic circuit. For example, the crusher jaw will slow while the blade is being raised. This can cause a rock jam. For
best performance, no rocks should be in the hopper or being crushed while the blade is in motion. The crusher jaw does not slow while the dozer is moving because the dozer uses its own hydraulic circuit.
The Sweco model 450 has 65 horsepower and the model 480 has 84 horsepower, which accounts for the longer time required for the model 450 to crush the same type and amount of rock. The shape and hardness of rock affects crushing time, as does the timing and rhythm of the “feeders” (persons putting the rocks into the hopper). If the rocks are fed too quickly, the crusher will jam. The back inside panel of the hopper prevents rocks from lodging behind the jaw.
The crusher can be adjusted to crush rock to a – to w-inch size. Turning the adjusting screw hanges the jaw opening; the tensioner rods also eed to be tightened or loosened. If the crushed rock needs to be smaller than w inch, a 12-inch shim can be inserted behind the moveable jaw that brings the jaws closer together, resulting in an aggregate size of w inches to sand.
This crusher has one moving jaw and one fixed jaw. Most of the crushing occurs in the lower portions of the jaws. When the jaws begin to lose their efficiency, they can be detached and turned around (bringing the bottom to the top, same surface faces in) and used again until the entire jaw surface is worn.
Ensure that the moveable jaw is rotating in the correct direction or rocks will be thrown out of the hopper. The movable jaw must move up, in, and down. If it is moving in the other direction, reverse the hoses.
Do not run the crusher without the hopper secured. The jaws will forcefully throw rock bits 25 feet and higher into the air. Always wear safety gear: a hardhat; gloves; and ear, eye, and respiratory protection are mandatory. (See figure 4.) Dick Dufourd of the Deshutes National Forest has experimented with a number of earplugs and found that the Howard Leight Max with a noise reduction rating of –33 decibels is effective.
The following additions to the Sweco are recommended:
• A rearview mirror and hand signals for communication.
• A mud flap between the dozer fan and the crusher to prevent those persons feeding the rocks into the hopper from becoming covered with and blinded by dust. Use a piece of bent rebar to dislodge jammed rocks. Turn the crusher off before removing stuck rocks.
A thorough search of the rock crushing industry revealed that rock crushers generally are either large enough for freeway construction or small enough for use in a materials testing laboratory. jaw crushers , however, are appropriate for the rock size usually crushed on a trail. All crushers researched, except for the BICO, were too heavy or too large for use on trails, or too expensive. They are all considered portable.