Altec DRM 12, Руководство пользователя

Страница: 73 / 143

10
Appendix — Glossary
pole guide tongs — moveable arms on a pole guide used to stabilize
and guide a utility pole as it is being raised or lowered with the winch
line.
pole puller — an apparatus consisting of a hydraulic cylinder, chain
and other components used to loosen a utility pole from the ground.
pole setter — an assembly attached to the mast of a pressure digger
that is used to pick up, position, and set a pole.
polyethylene — a moisture proof plastic.
poppet — that part of certain valves that prevents flow when it closes
against a seat and allows flow when it moves away from the seat.
port — an internal or external opening for intake or exhaust of fluid
in a component.
portable resistivity tester — a device used for testing the electrical
resistance of water. Commonly used for testing the wash water for
insulator washers.
position — a term which describes the number of possible positions
a valve spool or mechanism can be shifted to.
post mount — a mounting configuration for an aerial device in which
the turntable is mounted on a pedestal which utilizes a round vertical
tube as its primary load-carrying structure.
potentiometer — a variable resistor that is connected to act as an
electrical voltage divider.
pour point — the lowest temperature at which a fluid will flow or pour
under specific conditions.
power — work per unit of time, measured in horsepower (HP) or
watts.
power module — the central connection point between the chassis and
unit electrical systems. This device is used to provide battery power to
the unit when the truck/machine selector is in the machine position.
power take-off (PTO) — a supplementary mechanism enabling ve-
hicle engine power to be used to operate non-automotive apparatus
such as a pump.
precharge pressure — the pressure of compressed gas in an ac-
cumulator before any fluid is added.
pressure — the force applied in a given area. It can be expressed in
pounds per square inch (psi).
pressure compensator — a device on a variable displacement
pump that adjusts pump output flow to develop and maintain a preset
maximum pressure.
pressure differential — the difference in pressure between two points
in a system or component.
pressure drop — the reduction in pressure between two points in a
line or passage due to the energy required to maintain flow.
pressure gauge — an instrument which displays the hydraulic or
pneumatic pressure sensed at a port on the device.
pressure line — the line carrying fluid from a pump outlet to the pres -
surized port of a valve or actuator.
pressure override — the difference between the cracking pressure of
a valve and the pressure reached when the valve is passing full flow.
pressure reducing valve — a pressure control valve whose primary
function is to limit its outlet pressure.
pressure switch — an electric switch which is actuated when the hy-
draulic or pneumatic pressure applied to a port on the switch reaches
a specified value.
pressure transducer — a pressure measuring device which produces
a variable electrical signal that is proportional to the hydraulic pressure
applied to a port on the device.
proportional circuit — a circuit that supplies a varying voltage to a
coil in a pilot valve as electrical current applied to the circuit is varied
by a hand control.
proximity alarm — a system which measures the distance from a
detector to another object, and sounds an alarm when this distance
is less than a specified value. Commonly used to inform the operator
of an HLIW of the distance between the boom tip nozzle and a power
line insulator or support structure.
psi — pounds per square inch.
PTO — see power take-off.
pulling arms — mechanical structure used to attach the platform to
the boom tip and supports the fairlead receptor tube.
pinion — a gear with a small number of teeth that has been designed
to mesh with a larger gear.
pintle hitch — a common heavy duty coupling type which utilizes a pintle
hook attached to a tow vehicle to pull a trailer having a lunette eye.
pintle hook — the “jaw” portion of a pintle hitch which attaches to
the tow vehicle.
piston — a cylindrically shaped part that fits within a cylinder or cy -
lindrical bore and transmits or receives linear motion by means of a
connecting rod or other component.
piston pump — a pump in which motion and force are applied to fluid
by a reciprocating piston(s) in cylindrical bore(s).
pivot weldment — the structure located above the slide frame on a
pressure digger which supports the mast.
placard — 1: a thin sheet of rigid material which is attached to another
surface by adhesive and/or mechanical fasteners, and is used to convey
instructions, information and warnings.
2:
May also refer to a decal.
planetary gear set — an assembly of meshed gears consisting of a
central gear (sun gear), a coaxial internal tooth ring gear and several
intermediate pinions (planet gears) supported on a revolving carrier.
planetary gearbox — a gearbox containing one or more planetary
gear sets.
platform — the personnel-carrying component of a unit, mounted at
the upper boom tip.
platform elevator — a mechanism, at the boom tip, to which the plat-
form is mounted, allowing vertical motion of the platform with respect
to the rest of the boom tip.
platform heater — an electrically powered device mounted in a splicer
platform which is used to warm the occupant.
platform leveling system — a system which keeps the bottom of a
platform parallel to or at a fixed angle to the base plate of the turntable,
or parallel to level ground, as the boom is raised or lowered. The system
may be mechanically, hydraulically, or gravity operated.
platform liner — a component made of material having a high dielectric
strength which is designed to be inserted into a platform to cover the
walls and bottom of the platform.
platform pin — the horizontal pin that is used to fasten a platform
mounting bracket to the upper boom tip. The mounting bracket pivots
about this pin for platform leveling or positioning.
platform rest — the structural member attached to the chassis or body
to support and cushion the platform in the travel or rest position.
platform ring — a metal band around the lip of a splicer platform
which supports and guides the platform as it is rotated about its verti-
cal centerline.
platform rotation override system — a system which allows the
zone of platform rotation to extend beyond a predetermined limit when
actuated by the operator.
platform rotator — a system which allows the operator to rotate the
platform about a vertical axis. This permits the position of the platform
to be changed with respect to the boom tip.
platform tilt system — a system which allows the operator to adjust
the orientation of the platform about a horizontal axis. Some systems
allow the operator to adjust the working position of the platform floor
and tilt the platform for cleaning. Other systems allow tilting of the
platform for cleaning but do not provide for operator adjustment of the
working position.
platform use — the stability criteria for a digger derrick mobile unit
which indicates that the load capacity chart and stability requirements
apply to the use of the derrick with the platform occupied, with no lifting
of loads with the winch line.
plunger — a cylindrically shaped part that is used to transmit thrust;
a ram.
pole — a long cylindrical piece of material such as wood, metal, or
concrete which is installed in a vertical position for use as a support
structure for power and communication lines.
pole guide — a mechanism at the tip of a boom used for guiding and
stabilizing a utility pole while using the winch line to raise or lower
the pole.
pole guide tilt cylinder — the hydraulic cylinder which is used to tilt
(raise or lower) the pole guide.
pole guide tong cylinder — the hydraulic cylinder which opens and
closes the pole guide tongs.