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

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81. Ad jus t men t 0 f the A- end c e n t e r i ng p Luti g e r s . - The
reference drawings for this adjustment are number 274247, Aend
assembly, and number 274251, control linkage assembly.
The centering plunger assemblies have been adjusted at the
factory to maintain the pump yoke at a slight offset towards
the hoisting position. The pump is offset enough to supply
oil to overcome the leakage of the system and to build up
enough pressure to retract the centering plungers and to release
the brake. and operate the safety car stop device. No
adjustment is necessary until the parts of the equipment have
worn enough to permit increased leakage and prevent the proper
functioning of these devices.
The adjustment of the centering plungers is made by shimming
the complete centering plunger assemblies to the desired position.
When this adjustment is made it will be necessary to
readjust the control rod 274254-2 or 274251-2 which connects
between the control linkage rocker shaft and the A-end control
lever. The procedure is as foilows:
Remove the pipe flanges 271724-4 from both centering
plunger housings 274304-1. ..Remove the six long
screws 274340-2 from each assembly and the centering
plungers can be removed from the uni t. Next disconnect
clevis 274253-5 from the control rod lever
274254-1. Nowremove .010 inch of shim stock from
shim 274305-9 under centering plunger housing (long
plunger 274306-1). This will shift the pump yoke
farther towards the hoisting direction. Next add
the same amount of shim stock under the opposite centering
plunger. Replace the centering plunger assemblies
and the pipe flanges. Control rod 274254-2
or 274251-2 is to be adjusted for length as explained
in the preliminary adjustments. If the .010 inch
adjustment is not 'enough· to make the above units
function properly, additional shims must be removed
from centering plunger 274306-1 and added to the
other until proper functioning is obtained. After
adjustment of the centering plunger it may be necessary
to readjust limit switch 231705, located on
the top of the A-end. See paragraph 82.
82. Adjustment of the A-end neutral interlock switch.-
Refer drawing number 231705. The limit switch has been adjusted
at the factory to just close when the operator's control
lever is in the "Stop" position, to prevent starting the
electric motor until the pump yoke is returned to its centered
position. A change in the adjustment of the centering plungers
may affect the limit switch, which is adjustable as follows: