(1) Loosen nuts (4) before making adjustment.
4-71. Crusher Discharge Opening
(2) Loosen tension if crusher is to be adjusted
The crusher discharge opening is the distance from the
for finer crushing.
valley between corrugations on one jaw to the top of the
mating corrugation on the other jaw. The crusher
Crusher must be adjusted when empty
discharge opening governs the size of finished material
produced by the crusher.
Toggle plate length ........................................19 inches
a. Measuring Discharge Opening.
Crusher discharge opening ............................1/2 inch minimum, 4 1/2
(1) Measure distance at bottom of jaws at the
point of the crushing cycle when bottom of jaws are
The above setting is the recommended
(2) Turn flywheel so that counter weights are
minimum opening. Maximum opening is
parallel with movable jaw.
determined with new jaws and toggle
(3) Using a piece of lumber as a "feeler gage"
check the distance between the valley of the
corrugations on one jaw to the crown of the corrugations
Never close crusher discharge
opening to less than minimum
opening of 1 1/2 inches. Closing
crusher opening to less than
recommended will reduce capacity of
crusher and cause premature failure
of shaft and bearing assembly.
Crusher opening should be determined when operating
in conjunction with the secondary crushing and screening
plant to obtain a balanced flow through plants. Also size
of material to the secondary is determined by the roll
crusher opening. See chart in Secondary Crushing and
Screening Manual to determine maximum size material
to feed roll crusher.
attach hose from pump to ram. Pump until ram pushes
the movable toggle seat forward to release pressure on
(4) When shims are free either remove or insert the
same thickness and number of shims in the two packs.
(5) Release pressure in hydraulic pump to allow
movable toggle seat to slide back against shim packs.
(6) Tighten nuts before starting crusher.
(7) Replace cover plate to keep back of base and
adjusting shims free from dust or dirt.
(8) Tighten tension spring to keep toggle plate from
chattering or pounding.
(9) To compensate for wear on toggle plate, toggle
seat, pitman toggle seat and jaws additional shims must
be inserted to maintain the same crusher opening.
Figure 4-65. Measuring crusher discharge opening.
Before attempting to crush rock
remove hydraulic ram from crusher
and adjust discharge opening as follows: