i am working on this for my project. so i need some description about it

I think fallowing links will be helpful.
http://www.mekanizmalar.com/material_feed_mechanism_pictures.html
http://www.mekanizmalar.com/raoul_el_dib.html

how did you decide the dimensions of the links to be used in this mechanism,i mean if the arm is say 5 units then the rocker arm has to be 10 units but not 9 or 11 units??

It is well known mechanism. Please look at the links at the second comment to find further info.

Is this mechanism used in modern or recent times?
or is this outdated?
If this is still used,then where?

I have select this mechanism as my mini project. There is lot of confusions while doing design . . . How did you calculate the distance between the pivots. . . Would you pls explain me. . . . . . . .

It is an Excellent Mechanism Animation

what is the crank length?

i did this as a project, but i not able to produce enough distance required to move the box from one teeth to another....

Is it a four bar mechanism or 6 bar?

Rotating hinge and left hinge linkage system forms a four-bar mechanism.

What is the major mehanism used for this like double crank or any other