2. INTRODUCTION
An escalator is a power-driven, continuous moving
stairway designed to transport passengers up and
down short vertical distances.
Escalators are used around the world to move
pedestrian traffic in places where elevators would be
impractical.
4. There are two types of companies that supply
escalators:
Primary manufacturers who actually build the
equipment
Secondary suppliers that design and install the
equipment.
In most cases, the secondary suppliers obtain the necessary
equipment from the primary manufacturers and make
necessary modifications for installation.
Therefore, most escalators are actually assembled at the
primary manufacturer. The tracks, step chains, stair
assembly, and motorized gears and pulleys are all bolted into
place on the truss before shipping.
5. The first stage of escalator construction is to establish the
design and accordingly the manufacturer constructs the
appropriately customized equipment.
Prior to installation,
the landing areas
must be prepared
to connect to the
escalator.
For example,
concrete fittings must
be poured, and the
steel framework that
will hold the truss in
place must be attached.
After the escalator is
delivered, the entire assembly is uncrated and jockeyed
into position between the top and bottom landing holes.
10. FLOOR PLATE
The floor plate provides
a place for the passengers
to stand before they step
onto the moving stairs.
This plate is flush with the finished floor and is either
hinged or removable to allow easy access to the
machinery below.
11. COMB PLATE
The comb plate is the
piece between the
stationary floor plate
and the moving step.
It is so named because its edge
has a series of cleats that
resemble the teeth of a comb.
These teeth mesh with matching cleats on the edges of the
steps.
This design is necessary to minimize the gap between the
stair and the landing, which helps prevent objects from
getting caught in the gap.
12. THE TRUSS
The truss is a hollow metal structure that bridges the
lower and upper landings.
It is composed of two side
sections joined together with
cross braces across the bottom
and just below the top.
The ends of the truss are attached to the top and bottom
landing platforms via steel or concrete supports.
The truss carries all the straight track sections
connecting the upper and lower sections.
13. THE TRACKS
The track system is built into the truss to guide the step
chain, which continuously pulls the steps from the
bottom platform and back to the top in an endless loop.
14. There are actually two tracks: one for the front wheels of
the steps (called the step-wheel track) and one for the
back wheels of the steps (called the trailer-wheel track).
The relative positions of these tracks cause the steps to
form a staircase as they move out from under the comb
plate.
15. THE STEPS
The steps themselves are solid, one-piece, die-cast
aluminum.
Rubber mats may be affixed to their surface to
reduce slippage, and yellow demarcation lines may
be added to clearly indicate their edges.
16. The steps are linked by a continuous metal chain so they form a
closed loop with each step able to bend in relation to its
neighbors.
The front and back edges of the steps are each connected to two
wheels.
The rear wheels are
set further apart to
fit into the back
track and the front
wheels have shorter
axles to fit into the
narrower front
track.
As described
above, the position
of the tracks controls
the orientation of
the steps.
18. PHYSICAL FACTORS:
Physical factors like the vertical and horizontal distance to be
spanned must be considered.
These factors will determine the pitch of the escalator and its
actual length.
LOCATION:
Escalators should be situated where they can be easily seen by the
general public.
In department stores, customers should be able to view the
merchandise easily.
Furthermore, up and down escalator traffic should be physically
separated and should not lead into confined spaces.
19. TRAFFIC PATTERNS
Traffic patterns must also be anticipated in escalator
design.
In some buildings the objective is simply to move
people from one floor to another, but in others there
may be a more specific requirement, such as funneling
visitors towards a main exit or exhibit.
The number of passengers is important because
escalators are designed to carry a certain maximum
number of people.
For example, a single width escalator traveling at
about 1.5 feet (0.45 m) per second can move an
estimated 170 persons per five-minute period.
20. SAFETY
Safety is also major concern in escalator design.
Fire protection of an escalator floor-opening may
be provided by adding automatic sprinklers or
fireproof shutters to the opening, or by installing the
escalator in an enclosed fire-protected hall.
To limit the danger of overheating, adequate
ventilation for the spaces that contain the motors
and gears must be provided.
It is preferred that a traditional staircase be located
adjacent to the escalator if the escalator is the
primary means of transport between floors.
21.
22. WORKING
An escalator is a continuously moving staircase. Each stair
has a pair of wheels on each side, one at the front of the
step and one at the rear. The wheels run on two rails. At
the top and bottom of the escalator, the inner rail dips
beneath the outer rail, so that the bottom of the stair
flattens, making it easier for riders to get on and off.
25. ESCALATOR WIDTH
In accordance with a worldwide standard,the
width of the step to be used is 60 cm
(for one person), 80cm (for one-to-two people)
and 100cm (for two people width)
26. ESCALATOR ANGLE
Escalator angle can be between
30-35 degrees.
The 35 degree escalator is more
economical, as it takes up less
surface area if viewed in plan, but
for large ascents, the 30 degree
escalator is preferred both on
psychological as well as safety
grounds.
The transportation capacity is same
27.
28. BENEFITS
Capacity to move large
numbers of people.
Can be placed in
the same physical
space as stairs.
Have no waiting
interval,
except during
very heavy traffic.
Used to guide
people towards
main exits
or special exhibits.