Writing Feedback / Short explaination of Bell - English learning [2]

Hi everyone,
I'm trying to refresh my English again. I write a simple short text on this purpose. I need your help to improve and correct it. Thank you very much in advance.

Bell
Abstract
A bell is a percussion instrument designed to produce sound. The use of bells is commonly known worldwide. Bells are used for different purposes, such as to mark the course of time in a clock tower, to warn people of emergency situations, and sometimes for entertainment. This short report describes basic components of bell.

Body
The body of bell usually made of metal, but in some case the body could be made of ceramic or glass. To avoid cracking, it has cup shaped cylindrical known as bell-shaped. The reason for the increasing diameter of bell from the top to the bottom is so that the bell resonates at different frequencies and makes bell more musically pleasing.

Clapper
A bell generate its sound when a hitter, named clapper, hit the body of the bell by swinging the clapper. A clapper hang on the inner side of a bell's head.

Crown
A crown is a bell's component, that holding the bell. A crown requires a strong and durable material, because it has a function for holding the bell; not only it's own self-weight but also the force from the clapper and wind load.