How does an Electric Demolition Hammer Work?

What is a demolition hammer? 

A demolition hammer is a machine that is used to break or fracture hard materials such as masonry, brick walls, concrete, tiled flooring etc. An electric demolition hammer uses power from a wall outlet or from a battery source to generate impact energy. The energy is directed to a chisel which in turn delivers the impact to the material to be demolished.

How does it work?

The basic premise for most роwеr tools is to harness the rotary power generated by a motor for useful applications such as cutting, drilling or as in this case hammering. For the purpose of demolition, a high torque motor is used with a thick and heavy armature winding and a heavily wound stator or field coil. The motor drives a reducing gear mechanism connected to a rotary crank shaft at a 90° angle to its axis. 

A Piston attached to the end of the crank shaft oscillates inside a cylinder. The piston has rubber O-Rings to create an air-tight seal with the cylinder. 

At the other end of the cylinder is a Anvil / impactor that holds the demolition chisel. This anvil is allowed a few millimeters of movement and is lodged inside the cylinder and sealed with rubber O-rings.

Between the piston and anvil is a Ram. The ram is also sealed with rubber O-rings so as to create a pneumatic seal inside the cylinder. The ram is free to oscillate between the piston and the anvil. The seals help create an air cushion between the piston and the ram. This air cushion insulates the piston from any recoil from the ram.

A typical part diagram for a 5kg Demolition Hammer

At the anvil end of the cylinder, air release holes are provided so that the air between the ram and the anvil is expelled when the ram is pushed towards the anvil. The ram thus oscillates along with the movement of the piston and impacts the anvil repeatedly to create a hammering action on the chisel lodged inside the anvil. 

The rotary power of the motor has thus been harnessed for the purpose of demolition. Using this simple mechanism a demolition hammer can execute many different types of jobs such as chipping, grooving, demolition, breaking etc. 

Demolition hammers are typically used to break masonry materials, asphalt etc. each application requiring a different impact energy. Demolition hammers are hence available in 

1. different configurations such as L-shaped, In-Line etc depending on the application. In-Line ones are best suited for breaking the floor, whereas L-shape ones are best suited for wall applications.  
2. different weights - 2Kg, 5Kg, 10Kg, 16Kg, 30Kg etc having different impact energies

At Shree Venkateshwara Traders, we have a range of demolition hammers for wide variety of applications from some of the world's most reputed tool brands. 

We also take great pride and specialize in the repair and service of these machines. We are authorised dealers and service partners for DeWalt, Stanley, Black + Decker & Makita.