OP-755 Part 2 Pages 197-401 - Personal Page of GENE SLOVER
OP-755 Part 2 Pages 197-401 - Personal Page of GENE SLOVER
OP-755 Part 2 Pages 197-401 - Personal Page of GENE SLOVER
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275<br />
(d) On the end <strong>of</strong> the output shaft is located the<br />
steel cam housing. This provides a mounting<br />
for the outboard bearing <strong>of</strong> the output shaft.<br />
It includes reduction gearing which drives a<br />
cam support assembly. This cam support is<br />
geared to the output shaft so that it turns<br />
less than one revolution for a flight <strong>of</strong> 53<br />
feet <strong>of</strong> the hoist. There are four cams which<br />
are secured to the cam support and they control<br />
the hoisting and lowering, acceleration and<br />
deceleration rates. These cams are adjustable<br />
for positioning the flight, and also for controlling<br />
the length <strong>of</strong> the flight.<br />
(e) At the lower end <strong>of</strong> the eam housing are 10cated<br />
a rocker arm and shaft unit which transmits<br />
motion limited by the cams, to the control<br />
rod to the A-end. This motion is in turn<br />
transmi tted to the A-end through the control<br />
linkage, and limits the amount that the pump<br />
may be <strong>of</strong>fset. This determines the maximum<br />
speed <strong>of</strong> the hoist. Access to the cams and<br />
gears is obtained by removing the large steel<br />
inspection cover on the face <strong>of</strong> the carn housing.<br />
(f) The brake operating linkage is secured to the<br />
welded steel base, and consists <strong>of</strong> a pressure<br />
operated cylinder, links and levers to release<br />
the brake 'band. The brake is applied by venting<br />
the brake cylinder, which allows the spring<br />
in the brake cylinder to move the piston and<br />
linkage to tighten the brake band. When the<br />
brake is released, the steel band is forced<br />
out to rest against five adjustable stops,<br />
which hold the band away from the brake drum,<br />
to prevent excessive wear.<br />
(g) A foot valve assembly is mounted on the inlet<br />
flange face <strong>of</strong> the hydraulic motor. The control<br />
lip-kage for the foot valve is mounted on<br />
the base plate. The foot valve functions to<br />
prevent the car from lowering at the start <strong>of</strong><br />
a cycle, while the brake is released and the<br />
main circuit pressure is building up sufficiently<br />
to support the load. Also when stopping,<br />
after the main circuit is vented, the<br />
foot valve holds the load until the brake has<br />
had time to apply. The foot valve functions<br />
only at beginning and the end <strong>of</strong> the cycle, as<br />
its control linkage is mechanically connected
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