PDX_31_Specialties / Conveying Systems Flashcards
ANSI/ASME code A17.1
Safety code for elevators, dumbwaiters, escalators, and moving walks
American industrialist who invented the safety device that prevents elevators from following is the hoisting cable fails
Elias Otis
NFPA
Fire safety and electoral standards for life safety
National elevator industry Inc. (NEII)
Standard layouts and suggested minimums for accessibility
1.6 x building height + 350 =
Elevator speed
Stairs may be as narrow as__but when loads are over 50 people, they must be__wide:
36 inches minimum,
44 inches minimum, 50ppl +
Max stair rise, min stair run:
7” max rise, 11” min run
Nosings have a maximum rounded edge of
Half-inch
Hey drill diameter between__and at least__away from wall:
Diameter 1-1/4” – 2”
Min 1-1/2” clr from wall
Ramp slope, Max rise, Max run, landing dimensions
Minimum 1:12
Max rise of 30”
Max run 30’
60” landing
Minimum ladder width
18 inches wide minimum
– Used for lowrise or less than five story buildings, about 50’0”.
– Speed varies between 25 – hundred and 50 ft./m
– Carrie about 10 tons
– Freight
– Cylinder extends as far into the ground as it is tall (So they don’t require penthouse Machine room or heavily braced roof over shaft.
Hydraulic elevator
Uses a telescoping plunger set into the shaft next to the cab. Lift is provided by applying force to the upper member of the car frame.
Holeless hydraulic
– Commercial/industrial greater than five stories/50’0”
– Up to 1800 ft./m
– Up to five times
Electric (traction ) elevator
Counterweights in electric elevator weigh:
The weight of an empty car + 40% of live load capacity
Electric elevators use gears when
High-speed installation
New motor and break on one shaft which drives a second main shaft
Electric elevator double wrap:
Cables Passover the sheaves twice, get worn out faster, used for high-speed elevators where more traction is required
When the rope is wrapped around achieve on the counterweight and connected to the top of the shaft the rope moves twice as fast as the car, but requires less wait to be lifted.
1:2 roping
Freight elevator speeds range from:
50 ft./m to 200 ft./m
Mounted on shaft and operated by the control mechanism. Self applying so the car will stop in the event of a power failure.
Main break
Measures and limits the elevator speed by means of the control panel. It will actually the safety rail clamp if the elevator tries to exceed its proper rate of travel.
governor
Grip the sides of the rails if there is an emergency
Safety rail clamps
Located on the bottom to stop the car if it over travels at low speed… Won’t do much to stop a car traveling at a higher speed
Car buffers/bumpers