The pumps can also be manually operated through
the stroke-control switch, which is wired in series with
the tailrod switch. Both switches must be in the ON
position for the pumps to be placed onstroke. The
stroke-control switch is used to turn the pumps
offstroke before starting the pump-motor sets, so that
they may be started and operated for a few minutes
without a load.
For C-13 catapults, automatic operation of the
pumps is accomplished through the action of a tapered
spear bolted to the air side of the air/oil separator
piston. As the piston is forced toward the air end of the
accumulator, the tapered spear comes into contact with
a lever and roller assembly
shaft located in the end
enters the cap, it causes
cap
the
attached to a horizontal
(fig. 4-47). As the spear
lever and shaft to rotate,
causing a cam on the end of the shaft to actuate the
stroke control limit switch, causing the pumps to go
offstroke. As the fluid is displaced to various
components of the catapult, air forces the piston away
from the actuator assembly, allowing the cam to rotate
off the switch and causing the pumps to kick onstroke
automatically. Manual operation is basically the same as
on the C-7/C-11 catapults.
NOTE
Always ensure that the stroke control
push button is in the OFF position prior to
turning on the pumps. The C-13 catapult also
incorporates a hydraulic volume normal switch
that performs the same function as on the
C-7/C-11 catapults.
4-37
Figure 4-47.—Linear retraction engine accumula
