Slat Conveyors and Spreading Screws
IMPORTANT! The slat conveyors are
Two slat conveyors move material from the bottom of
built to run in only one direction. When
the receiving hopper through parallel tunnel areas to each
the paver is shifted into Reverse gear for
backing, a micro switch at the gear box is
of the two spreading screws which operate in conjunction
actuated to open the conveyor clutch
with the slat conveyors. The depth of material moved is
circuits so that no reverse movement of
varied by manual adjustment of fixed gates located at the
the slats can occur. This limit switch
head end of each tunnel. (See Figure 5)
Slat speed is fixed, unless an optional two-speed
(Section 8, Figure 4) must always be
transmission unit is purchased to permit a 30% speed
kept in adjustment!
shift when required. With the fixed speed arrangement
the drive may be either the high or the low range.
Each slat conveyor and its companion spreading screw
The two spreading screws which operate in conjunction
are controlled by electric clutch action. The clutches can
with the slat conveyors receive material as it is brought
be engaged manually by toggle switch movement at the
through the tunnel areas near the center of the tractor
operators console, or can be controlled automatically by a
unit. The opposing pitch of the screw blades forces the
material depth feeler if the console toggle switch is set at
material outward toward the ends of the screed. A set of
AUTO. (See details of automatic operation in following
special blades on each spreader screw at its inner end
paragraphs covering conveyors).
has a reverse slant which assures placement of adequate
material in the center area. Agitators at the outer end of
each screw perform a stirring function to prevent material
compaction by the screws against the retaining blades.
Spreader screws are offered in two diameters for
different feeding rates; 12" diameter for lower volume
feeding and 14" diameter for higher volume feeding.
Whenever extreme wear reduces the diameter of a screw
by ½ the tips should be built up or the blades refaced to
the original O.D. (See Maintenance Section 11).
When less than 10 ft. wide paving is done, the end
flight of the screw on the cut-off side is uncoupled by
sliding a key outward. When uncoupled the outer flight no
longer moves material. (See Figure 5).
Bottom View of Tractor Assembly