OP-755 Part 2 Pages 197-401 - Personal Page of GENE SLOVER

207
Although at the start the operating lever (8) is
moved the full distance the yoke can only be offset
a slight amount, limited by cams (16) or (17). The
full movement of the operating lever is made possible
by offsetting and compressing the centering spring
within the control link (12). This spring under compression
exerts a force causing the link roller to
follow the contour of its timing cam throughout the
cycle, thus governing the pump offset. In the position
as shown on the schematic diagram of figure 32,
the cams permit only, a slight offset of the pump
yoke, just sufficient to overcome the normal internal
leakage and to start the hydraulic motor (6) rotating.
14. Start position,figure 33. - The movement of the
operating lever rotates the cam (24), forcing the roller to
move out of notch and depress the starting valve (25). When
the starting valve is depressed the auxiliary pump pressure is
ported from line (26) into line (27), around spool of interlock
valve (28) to line (29) and into chamber (30). Pressure
now acts on the differential area of piston (33) and moves it
to the positive stop on valve bLock. The movement of this
piston shifts the control valve (31) to i ts mid-position, where
it is held by spring (32). Valve (31) now ports pressure from
40
OPERATING LEVER
NEUTRAL J
Fig. 33 - Projectile Ring Circuit Diagram
Starting Position
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27
26