hand lever which is connected with the piston as-
The bell-crank moves the rack in the fuel pump
sembly by mechanical linkage. The transmitter
to the ON position.
assures a wide range of control of the fuel in-
d. The function of the double relief valve is to
jector pump rack setting, since the positive fric-
develop a positive head in the control hose and
tion lever may be set at any desired operating
to keep the control hose full of oil, making it
position. The transmitter reservoir includes a
unnecessary to pump up pressure after the trans-
breather cap which must be opened before at-
mitter lever is returned to the OFF position, es-
tempting to start and run the hammer. If the
pecially when the receiver is located at a height
hammer is to be shut down for overnight or ex-
above the transmitter where the oil pressure
tended periods of time, or if the transmitter is to
be removed from the machine, this breather cap
head exceeds barometric pressure (in excess of
must be closed to prevent loss of control oil or
approximately 36 feet). No adjustment of the
entry of foreign material in the reservoir.
relief valve is provided. The preloaded head of
c. By moving the control lever to the ON posi-
oil in the system is maintained by springs in the
relief valve. The relief valve will maintain ap-
tion, a column of oil is moved through the double
proximately 40 psi. of hydraulic pressure in the
relief valve and then through the hose to the re-
system with control valve in either the OFF or
ceiver. As the receiver piston moves downward
out of its cylinder, it in turn moves a bell-crank.
SYNCHRONOUS positions.
Figure 3-9. Hydraulic hose, receiver, and
transmitter, removal and installation.
3-8
