WHAT IS THE MEANING OF LIFT / ELEVATORS ? EXPLAIN ITS TYPES , COMPONENT PARTS AND ITS FUNCTIONS IN DETAIL.

Elevator / lift

A lift or an elevator is an appliance designed to transport living beings or materials between two or more floors in a vertical direction by means of a guided car or platform.

The lifts in multi-storied buildings are now a days very reorganized and important that no multi-storied buildings are planned without proper provision of lift system.

Nowadays it’s mandatory to install elevators or lifts in all the buildings whose height is 24 meter or more.

General requirements of lifts

1. in every building with height more than 16m, at least one lift should be provided.

2. for the buildings with more than 24m height, at least two lifts are provided.

3. the walls of the lifts shafts should have a fire resistance of not less than two hours.

4. the lift shaft should have a permanent vent at the top of area not less than 0.2m2 and at tan height of about 1.8 m.

5. the lift motors should be located above the lift and separated by the floor of machine room.

6. Landing doors in lift enclosures shall have a fire resistance of not less than 1 h.

7. Exit from the lift lobby, if located in the core of the building, shall be through a self-closing smoke stop door of half an hour fire resistance.

8. Telephone or other communication facilities shall be provided in lift cars for building of 30 m in height and above. Communication system for lifts shall be connected to fire control room for the building.

9. Alternate source of power supply shall be provided for all the lifts through a manually operated changeover switch.

10. Collapsible gates shall not be permitted for lifts and shall have solid doors with fire resistance of at least 1 h.

Essential features of lifts

A.  CAR

1. The initial feature of the lift is a CAR which helps to carry the passengers from one floor to another floor.

2. The care is supported on a cables which runs on a pulley and balanced by a container

 (Basically the cables are just like rope which are of very high quality materials so that it can lift very heavy loads of passengers and goods).

(Container is basically a counter weight we provide so that there will be balance between the can and container and hence resulting in a smooth working of the lift).

3. both the car and counter weight raise and falls between steel guides in the shafts when the lift is operated for the use. (lift shaft)

4. the pulley is connected with the motor and control gear in motor room over the lift well.

5. the top of the lift shaft is ventilated to the fresh air to avoid the rapid spreading of fire throughout the structure.

6. the speed of the lift is depends on the quantity of service required and the quality of service desired.

B. MACHINE ROOM

1. machine room is generally located above the lift well and generally the machine room a room in which the machine and working mechanism of lift is installed which includes the following.

Winding machine = motors, electromechanical breaks, warm up gear and pulley.

Controller which is mounted on a frame

The floor selector

Over speed governor

2 the machine room should be easily accessible and provided with locking arrangements.

3 the machine room should not be used as storage room.

4 machine room should be provided with proper lightening arrangements.

C. LIFT –WELL

1 basically a lift well means a space in which we run our lift or we can say that “it is an unobstructed space within the lift shaft “

2 it is the space provided for smooth, friction free movement of the car lift.

D. LIFT PIT

1. the lift shaft is extended down below lowest landing, generally its nothing but the sunken portion of the lift shaft which is constructed below the ground level or the lowest level of the lift.

2. the depth of the lift pit varies from 1m to 1.2m depending upon the speed of the lift car.

3. the construction of the lift pit should be such that it should be completely water tight and the area should remain dry during any season.

4. the lift pit is constructed for the purpose of providing support and easy movement of the car and balancing the movement of the car of lift. It becomes very important at the time of landing because in the lift pit we generally install spring system so that the car can settle very easily on the level.

E. LIFT LANDING DOOR

1 every lift has an open-able door from which there is an access to the landing.

2 the door must be fitted with efficient interlocking system or other devices to provide the security so that the doors cannot be opened except when the lift car is at the landing level and that the lift cannot moved up/down from the landing until the door is locked again.

E. LIFT CAR

1. The carrying unit with its floor or platform, car frame and enclosing body work

2. lift car has a basic frame work of steel, angles and channels, which is called as the sling incorporating the fixing for the guide shoes and the safety gears.

3. it is important that there is a good ventilation in the car. Either by simple grills or by concealed louvers on the roof.

TYPES OF LIFTS

There are primarily two types of lifts

1. passenger lifts and

2. freight / goods lift

1. passenger lifts

Passenger lifts are provided in apartments, high rise buildings and offices etc…

The size and speed of the lift is depends upon the services expected from the building.

2. goods lifts

Goods lifts are provided in industrial buildings to carry materials from one floor to another floor.

The size of the goods lifts are large to carry big cartoons or packages.

In hospitals this type of lifts are used to carry patients from one floor to another for the purpose of treatment.

In hotels also this kind of lifts become useful for taking food and other luggage from on floor to another floor.

Operation of an elevator or lifts

“The method of actuating the control of all the machines is called as operation” so from this definition we can say that the operation of elevator means controlling all the parts and mechanism of elevator for smooth working of it.

There are many ways through which we can operate the elevators, some of the methods are given below in short…

1. Automatic Operation

It’s a method operation in which, through momentary pressure of a button, the lift car is set in motion and caused to stop automatically at any required lift landing.

This is the most commonly used mechanism in all the lifts, be it on residential building or other commercial building.

2. Non Selective Collective Automatic Operation

With this type of operation, the car stops at all the landings for which the buttons have been actuated making the stops in the order in which the landings are reached after the buttons have been actuated but irrespective of its direction of travel.

3. Selective Collective Automatic Operations

With this type of operations, all the “up” landings are answered, when the car is traveling in the up direction.

And all the “down” landing calls are answered, when the car is traveling in the down direction.

In the case of upper most and lower most calls, they are answered as soon as the car reached irrespective of the direction of travel of car.

4. Single Automatic Operations

Aromatic operations by means of one button in the car….. For each landing level served and one bottom at each landing so arranged that if any car or landing buttons has been actuated , the automation of any other car or landing operation button will have no effect on the movement of the car until the response to the first button has been completed.

5. Group Automatic Operations

Automatic operations of two or more non-attendant lifts equipped with power operated car and landing doors.

The operations of the car is co-ordinate by a supervisory operation system including automatic dispatchin means here by selected cars at designated dispatching points automatically closed their doors and proceeds on their trips in regulated manners.

Typically it includes one button on each car for each floor served.

And up and down buttons at each landing.

6. Car Switch Operation

The method of operation by which the movement of lifts car is directly under the operation of the attendant.

7. Single Operation.

This operation is same as collective operation, except that the closing of the doors is initiated by the attendant.

8. Double Button (contentious operation).

Operations by means of switching in the car and at the landings any of which may be used to control the movement of the car as long as the buttons or switch is manually pressed in the car actuating position.

Other types or elevators are listed below

1. hydro static (low speed)

2. traction geared (medium speed)

3. traction gear less (high speed)