Escalators

a conveyor transport device for carrying people between floors of a building, specially where lifts/ elevators would be impractical

1. ESCALATORS

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 .

3. The manufacturing process

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.

6. components

7. Landing platforms An escalator consists of top and bottom landing platforms connected by a metal truss.  TOP PLATFORM BOTTOM PLATFORM

8. The top platform contains the motor assembly and the main drive gear . The bottom platform holds the step return idler sprockets

9. The platforms contain a floor and comb plate. COMB PLATE FLOOR PLATE

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.

17. Escalator design

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 : E scalators 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. 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.

22. TYPES: Escalator typical configurations: PARALLEL CRISS CROSS LAYOUT

23. WIDTH OF ESCALATOR CROSS-SECTION OF AN ESCALATOR

24. 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)

25. 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 for both.

26. BENEFITS Capacity to move large numbers of people. C an be placed in the same physical space as stairs. H ave no waiting interval, except during very heavy traffic. U sed to guide people towards main exits or special exhibits.

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