|
 A
freight elevator is
an elevator designed to carry heavy freights and
goods at a quick pace, rather than passengers.
(Passengers often accompany the freight, however.).
Freight elevators are typically larger and capable
of carrying heavier loads than a passenger elevator,
generally from 5,000 to 10,000 lb (2,300 to 4,500
kg). Freight Elevators may have manually operated
doors, and often have rugged interior finishes to
prevent damage while loading and unloading. As
compared to hydraulic elevators electric elevators
are more energy efficient for freight lifting. These
simple, flexible, durable, cost-effective and smooth
riding Freight Elevators help solve the complex
transportation requirements.
Freight elevators
are used extensively in places where bulk
commodities/goods needed to transport vertically
like factories, shopping centers and storage
facilities for the movement of goods between floors.
When planning freight elevator for a building,
careful consideration needs to be given to the type
of loading performed.
Freight Elevators
are generally available in two types-
Drumwound type without counterweight- This
lift is simpler in design and suited for low cost
installations. The movement of the lift is based on
the coiling and uncoiling of a wire rope on a
rotating drum. This leads to lesser rope stress and
longer life. These lifts are quicker to install and
require lesser space.
Traction type with counterweight- This lift
is a better machine design wise and also offers
greater safety to the user. This is achieved first
through the use of 3 or more independent wire ropes
stretched across the main traction sheave. Second,
there being no positive coupling between the lift
and the machine leads to greater safety as a slip is
permitted whenever there is an obstruction to the
lift travel. Unlike in the drum wound design there
is no overload on the motor in case of lift
overshooting at the top floor. Jerk free, smooth,
higher speed travel is possible. |
