The safety in a Elevator

             Nowadays elevators are highly developed in all respects. especially in the case of safety. the special safeties which are included in the modern elevators are

1. Door safety
    Door safety refers to the function of stopping elevator movement if any of the landing/car doors are open.

2. Different stop switches
    Stop switches are used by technicians or the emergency rescue people. Stop switches stop the elevator movements electrically.

3. Buffer safety switch
    Buffer switches are activated if the car/cabin or the counterweight is over travelled to the top or the bottom side of the hoistway/shaft. This will electrically stop the elevator from moving any further.

4. Over speed governing devices
    Overspeed governor or OSG is stopping the elevator both electrically and mechanically if the elevator speed is more than the rated speed. If the ropes holding the elevator brakes or the breaks fails to act the situation of over speed can occur. There are two types of OSGs. One will act in both up and down directions, one will only act in elevator cabin is moving in down direction.

5. Terminal limit switches
6. Terminal slowdown switches
7. Overload safety
8. Door sensors
9. Toe guards
10. ARD
11. Emergency lignting
12. Floor announcement
13. Door motor belt break switches
14. Osg swiches
15. Hand rail
16. Counter weight safety switch
17. Car and Landing door lock switches
18. Safety gear switch
19. Break function switches
20. Manual rescue safety switches


    W e will keep this list updated because each year the safety in the lift is getting smarter and smarter.

What is an elevator ( simple explanation )

     An elevator is a machine or very arrangement of machines used for the vertical transportation.   Nowadays space availability to build structures is less, so building with more levels are the only solution. Well, you all will be aware of the problems of climbing steps in tall buildings. So something should be needed and that is an elevator.

Elevators are of different types. But for now, we will discuss a simple usual elevator design.  For that, you have to have some knowledge about some specific terms used in this industry.

And that are listed below

1. Elevator shaft( hoistway)

As the name implies hoistway is the empty space where the lift car moves. Lift car if nothing other than which host people. And protects with all safety.

2. Guide rails

 as a train is guided by rail the elevator car is also guided by specially designed "t" shaped rails

3. Elevator motor

will be specially designed for the specific load and will have great performance as an elevator demands that are the essential terms. Other terms will be explained later.

Principle

The principle of an elevator (usual method) is like pulley, rope, bucket arrangement used to take out water from a well. There is an extension to that basic design, that is an extra load [ extension weight = weight of empty bucket + (load/2)] tied on the rope's  next side.you will be thinking why that extra weight? , that is for reducing the motor load and reducing the price of the elevator.

What the motor does is nothing other than rotating the pulley to the desired direction and desired speed( there may have gear arrangement ). Instead of a bucket, we use the car, and instead of the extra load, we use the counterweight. Counterweight will be also guided by a pair of guide rails. 

This figure also shows counterweight. You can see counterweight is guided with two rails.

The developed elevators have control panels and many safeties.

Safety may include

1. Over speed 

2. Loss of power

3. Overload

4. Rope break possibility

Etc.

what the control panel do is nothing other than controls the motor, that includes

1. Starting

2. Stopping

3. Speed controlling

4. Calculates the distance to be travelled by detecting the call buttons of all floors and also the call button inside the car.

5. Controls the displays inside the car and on each floor.

6. Floor level checking and correcting

7. Safety controls 

Etc.

Actually, all the points listed above are wast and including different mechanical arrangements and electrical( indicating, detecting, controlling ) arrangements. The weight of counterweight, size or rail( weight /meter ) is determined by elevator capacity.

Intention of the blog

The blog elevator study is intended for
 
1.Anyone who want to knew about elevator  

2.Working professionals in this elevator field

3.Beginners of this field

        This blog work is started on 1/26/2012 and currently improving by adding new data.  





               My name is sumesh pakkan and now this is my 8th month in this field.  I am starting this blog in order to have complete international information exchange, other than major company secrets.

              I will try to include every piece of information, i knew through the posts. All the personal who are interested to write some post can contact me by my email sumeshpakkan@gmail.com. And don't worry  i will publish the post in your own name if it is a valid post. Comment, and make the information exchange to come true.
              I also wish to say many institutes and personals are making fool out of students who are interested in the field and they makes money out of poor student's dreams. this should be terminated so i thought that it is very essential to have a open source place where they get all information free and the correct guidance. all the readers who have experience , have the responsibility to guide them.
so am repeating this blog is all of yours. Am not a very good professional, i have also doubt and errors. please correct me if you find any incorrect posts. thank you