The PIV Unit consists of two pairs of opposed curved
conical discs, mounted one pair on the constant speed
shaft of the unit and one on the variable speed shaft.
These opposed discs are keyed to the shaft, which enable
them to slide axially on the respective shafts. Power
is transmitted from one shaft to the other by a patented
P. I. V. chain of special construction which rests in
the Vee formed between these opposed discs and runs
at a diameter depending on the axial distance separating
the discs. The mechanism controlling the
axial movement causes one pair of discs to approach
each other as the other pair separates, so that the
chain rises in one pair of wheels by the amount that
it descends in the other.
The heart of the PIV unit is the all metal slatted chain
and the grooved wheelfaces. The slats in the chain move
laterally to engage the groove in the wheelfaces. Therefore
the chain can not slip. The pitch diameter of both pairs
of wheelfaces is controlled to an infinite number of
positions by the pivoting control levers and the control
Maximum speed setting
The input shaft wheelfaces are close together, forming
a large driving diameter. The output shaft wheelfaces
are automatically separated to form a small driven diameter.
Minimum speed setting
The input shaft wheelfaces are far apart, forming a
small driving diameter. The output shaft wheelfaces
are automatically closed to form a large driven diameter.