ACADs (08-006) Covered
1.3.4.2
1.3.4.5
5.2.1.9b
Keywords
Elevator, hoist, crane, governor, buffer,
Description
Supporting Material
Objectives
• 1. Explain the different types of elevators and
how they are classified.
• 2. Review the major components of an
elevator system.
• 3. List the safety systems incorporated into
elevator system design.
• 4. Discuss the types of hoist and cranes used
on site.
Basic Elevator System
Basic parts of an elevator
1.
2.
3.
4.
Car
Rails
Hoist-way
Machine Room
Types of Elevators that are used?
Hydraulic Type
• Elevator platform is pushed
up by hydraulic jack. Limited
in height due to length of
jack pole (must be buried
below unit), used in low
raise buildings. Load sits on
top of the platform.
Traction Type
• Uses a system of cables,
pulleys and counter weights
on a track/rail system.
Unlimited height, can be
modified for speed and
weight requirements. Most
common type USED.
Classification of Elevators
• Passenger elevatorsused for the movement
of personnel and
limited equipment.
Tend to be smaller in
size with car doors that
limit the entrance to
the unit ( open
sideways not up and
down)
• Freight elevator- used
for the movement of
equipment and heavy
loads. The enclosure
doors (Gates) open up
and down allowing a
wider entrance to car.
Safety Systems
• Governors- monitors the speed of the car and removes power to drive
motor and applies brake if moving to fast, If speed continues to build will set
the safeties to stop the car.
• Safeties- anchors the car to the building by gripping the rails with clamps,
activated by the governor.
• Buffers- large coil springs or hydraulic – coil shock absorbers which
cushion the car at the bottom stop.
• Hoist-way Door – interlocked to lock doors to the shaft and allow
elevator to move.
• Door Reopening Device- prevents doors from opening if
>18in from landing. Operates doors in pairs on unit.
• Door Closing Sensors- optical sensors or proximity sensors
which prevent closing the doors of the car if the opening is
blocked.
Hoist & Cranes
• Crane- a device for
lifting and moving
heavy weights in
suspension.
• Hoist- mechanical device used
primarily for raising and lowering
heavy loads but occasionally for
moving objects horizontally. It usually
consists of a block and tackle-a
combination of one or more fixed
pulleys, a moving pulley with a hook
or other similar means of attaching
loads, and a rope (or cable) between
them. Motive power for a hoist may
be either manual or supplied by an
electric motor. Electrically powered
hoists, commonly mounted to the
floor or wall, are used for varied
lifting and hauling operations in
factories and warehouses
Types of Cranes
• Overhead- most
common used at plant (
Bridge Crane). Typical
crane system with a
movable hoist
assembly.
• Mobile- crawlers, truck
mounted, rail mounted,
floating, aerial.
• Fixed- tower, telescopic,
level, self erecting, Deck
(Very large and heavy
load lift)
Basic Safety Concerns
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Only Qualified and authorized personnel shall operate equipment
A “ load Impact Area” shall be created for all lifts.
Unauthorized personnel shall not enter load impact area
Don’t ride the hook, sling, ball, or load when moving
Lift test will be done prior to using man baskets
Load limits shall not be exceeded except for testing
Personnel shall not stand or work under loads and lifting gear, or near cable, chains,
rope under tension
Winch lines, ropes, cables shall not be guided by hand
Operators will not leave controls while load is suspended
Counter weight area will be marked and barricaded to prevent entry
Use extreme caution when operations are within 25 ft of power lines
Secure hooks when moving cranes to prevent swinging
Use tag lines when moving loads to prevent swinging or twisting
Only one person shall give hand signals and be in control with equipment operator,
however the stop signal can be given by anyone. Line of sight shall be maintained.
Ensure unit is stable and secured on footing prior to load lifts.
Typical Hoist System
Crane with a hoist system
When THINGS go wrong?
Review and Questions????