Altec DRM 12, Manual

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7
Appendix — Glossary
hydraulic schematic — a drawing that uses common hydraulic symbols
to represent the hydraulic system of the unit.
hydraulic swivel — a fluid conducting fitting having two joined parts
that are capable of pivoting freely about each other to accommodate
motion of an attached hydraulic line.
hydraulically extendible jib — a jib boom that may be extended or
retracted by hydraulic power.
hydraulics — an engineering science pertaining to liquid pressure
and flow.
hydrostatic hydraulic system — any hydraulic drive in which a posi-
tive displacement pump and motor transfer rotary power by means of
fluid under pressure.
individual address setting — the code that identifies a specific
transmitter as the one emitting the signal corresponding to a specific
receiver’s reception address.
infeed chute
— tapered weldment attached prior to the feed/cutter
mechanisms, assisting in the centering of the tree canopy.
in-line — the installation of a component in series between two por-
tions of a hydraulic line or electrical conductor so that flow in the line
or conductor toward the component passes through the component
and continues on in the line or conductor on the other side.
instability — a condition of a mobile unit where the sum of the mo-
ments tending to overturn the mobile unit is equal to or exceeds the
sum of the moments tending to resist overturning.
insulating aerial device — an aerial device with dielectric components
designed and tested to meet the specific electrical insulating rating
consistent with the manufacturer’s name plate.
insulating digger derrick — a digger derrick designed for and manu -
factured with a fiberglass boom(s) for use around energized conductors
at a maximum of 46 kV phase to phase.
insulating liner — see platform liner.
insulating portions — those sections which are designed, main-
tained, and tested in accordance with the electrical requirements of
ANSI A92.2.
insulator — a device that isolates the energized conductor of a power
line from the support structure.
intercom system — a transmitter and receiver system that allows
two-way verbal communication between a platform operator and a
person at ground level.
interference — any energy that inhibits the transmission or reception
of electrical or radio signals.
intermediate boom (INT BOOM) — an extendible boom section
which is located between the upper boom and the lower boom in an
extendible boom assembly.
ISO — International Standards Organization.
jam nut — a nut that is screwed down firmly against another nut to
prevent loosening.
jaw clutch — see drum clutch.
jib — an auxiliary boom which attaches to the upper boom tip to extend
the reach of the boom.
JIC — Joint Industry Conference.
joystick — a two or three axis control lever which allows the operator
to simultaneously control multiple functions.
junction box — an enclosed central connecting point for electrical
wiring.
kelly bar — 1: for derricks see auger extension shaft. 2: the auger drive
shaft of a pressure digger which is extendible from the ram cylinder.
key — a parallel-sided piece that fits into grooves in two adjacent parts
to prevent movement between the parts. Often used as the driving
member between a shaft and a sheave or winch drum.
keyway — a groove that is cut in a shaft or bore for a key to fit into.
kilovolts (kV) — a unit of potential difference equal to 1,000 volts.
knife — the rotating blade on a chipper cutting mechanism.
knuckle — see elbow.
L-bracket — an L-shaped weldment that is used to connect a splicer
platform to the upper boom tip.
lanyard — a component in a personal fall protection system consisting
of a flexible, nonmetallic strap or rope with a connector at each end
for connecting a body harness or body belt to a specified anchor point
provided at the boom tip, used to catch and decelerate a person in a
fall from the platform. (As of January 1, 1998, the use of a body belt
for personal fall protection is prohibited by OSHA.)
lashing wire — a thin, solid wire which is wrapped in a helix configura -
tion around a length of suspension strand and adjacent communication
cable so that the suspension strand carries the weight of the cable.
lay — the length of wire rope in which one strand makes one complete
spiral around the rope.
layer — all wraps of winch line on a winch drum which are on the same
level between drum flanges.
leakage monitor system — a means by which current leakage is
measured through the insulating section(s) of a boom to confirm of
dielectric integrity.
leveling cable — the wire rope portion of a mechanical leveling system
that passes over the sheaves.
leveling chain — the chain portion of a mechanical leveling system
that passes over the sprockets.
leveling cylinder — 1: a cylinder that is used in a master/slave arrange-
ment in a hydraulic leveling system to hydraulically level the platform. 2:
the hydraulic cylinder that is used to tilt the pivot and mast weldments
of a pressure digger to either side of the vertical position.
leveling rod — a slender, round, fiberglass rod used in a mechani -
cal leveling system that passes through a unit’s boom to connect the
leveling chains or cables at each end of the boom.
leveling system — see platform leveling system.
leverage — a gain in output force over input force; mechanical advan-
tage or force multiplication.
lift cylinder — the hydraulic cylinder that moves the lower boom up
and down on a digger derrick or extendible-boom aerial device.
lifter cylinder — the hydraulic cylinder that moves the reel lifter
arms.
lifting eye — a shackle or weldment used for attaching chain, cable,
rope, etc. to a boom for material handling.
light emitting diode (LED) — a semiconductor diode that emits light
when subjected to an applied voltage. LEDs are used for electronic
display.
line — a tube, pipe or hose used as a passageway to move hydraulic
fluid.
linear
— in a straight line.
linear actuator — a device for converting hydraulic energy into linear
motion such as a cylinder or ram.
linear position transducer — an extendible length measuring device
which produces a variable electrical signal that is proportional to the
length to which the device is extended.
liner — see platform liner.
link — the secondary load-carrying structure of an articulating arm.
load capacity — (as defined by ANSI for digger derricks) the maximum
load, specified by the manufacturer, that can be lifted by the mobile unit
at regular intervals of load radius or boom angle, through the specified
ranges of boom elevation, extension and rotation, with options installed
and inclusive of stability requirements.
load holding valve — a hydraulic valve which blocks fluid flow from
a hydraulic actuator, such as a cylinder or motor, to prevent motion
when the control valve is not being operated or in case of a hydraulic
line failure.
load radius — the horizontal distance from the centerline of rotation
to the winch line load attachment point.
load sensing — (see sense line) the signal when a function is operated
that tells the hydraulic pump to stroke up from a non-stroked (neutral)
position to supply oil to that function.
lock washer — a solid or split washer that is placed underneath a nut
or cap screw to help prevent loosening by exerting pressure against
the fastener.
locknut — see self-locking nut.
lockwire — a wire that is installed to prevent loosening of fasteners
or components.
low voltage coating — a sprayed on layer that provides low voltage
insulating properties.