Portable type drilling machines

 Drilliing machine(portable type)

. the different types of portable drilling machines

.distinctive features and uses

Necessity

Portable hand drills of different types are used for certain jobs which cannot be handled on stationary drilling machines.

Types

There are  two types of portable drilling machines, power operated and hand operated.

Power operated drilling machines

Electric hand drill(light duty)

These are available in different forms. The electric hand drills has a small electrical motor for driving the drill. On the end of the spindle, a drill chuck is mounted. Electric hand drills used for light duty will have, usually, a single speed.

Electric hand drill (heavy duty)

This drill  has an additional features,the drill speed can be varied through a system of gears. This is particularly used for  drilling larger diameter holes.

Pneumatic hand drill

This type of drill is operated by compressed air. An air driven motor is housed in the casing, and a handle is fitted along with air pipe to operate the drill conveniently.

This drill is used where electrically operated drills are prohibited i. e. Explosives factories, petroleum refineries.

Hand operated drilliing machines

Different types of hand operated drilling machines. They are used in structural fabricatiion, sheet metal and carpentry, particularly where electricity or pneumatic supply is not available.

The ratchet drilling machine is commonly used in structural fabrication. Squre head, taper shank drills are used on these  machines.

The bevel gear type drilling machine is used for drilling small diameter holes up to 6mm.

The breast drilling machine is used for  drilling holes of larger diameter as more pressure can be exerted. Drills between 6mm to 12mm can be  used on these machines.