The application of pneumatic tools is vast. Pneumatic tools play an important part in anyone’s daily routine. There are pneumatic doors, air pumps, your automobile, vacuum cleaner, etc., which we use every day.
You cannot imagine a life without pneumatic tools as its application is all around. Such a tool is the air hammer.
Many people use it for engraving work on different materials. It can also help craftsman to cut metal objects in different size options. It has a simplistic design yet powerful usage. So, the question arises how does an Air Hammer work?
We will be explaining to you its work and the working principles in detail. Before that, it’s better to know what exactly an air hammer tool is and what its components are.
What is an Air Hammer?
An air hammer, which also has another name, air chisel, pneumatic hammers or power hammers is a hand held tool that uses the air force to produce the hammer’s motion with a piston’s help. It is designed to work with a variety of tools, depending on the functionality you need. It may appear complex, but the tool works on the simplistic pneumatic principle.
History
Almost 130 years ago, in the year 1890, Charles Brady King invented air hammers. Charles Brady King got it patented after four years. However, the work of air hammers became extensive after 30 years in the times of 1920s. It changed the technology how craftsman used to hammer different materials.
Initially, there were only a few materials on which the air chisel tool worked. With the advancements in technology, its application increased. In the 1930s, the speed by which air hammers used to carve was increased to two-three times per minute. It allowed craftsman to create smooth design work on marbles and other stones rapidly.
Further, after the 1940s, the application of pneumatic hammers grew rapidly. Air hammers are now used as pavement breakers, cleaning up concrete, plating rack scalers, and a lot more. Without air hammers, a lot of tasks would become tough as other tools won’t be able to perform it. You can check also what tools does a mechanic need!
Why air hammers use compressed air?
There are a lot of examples where air compression is used to exert pressure. For instance, consider bicycle tires.
The tires hold the weight due to the pressure exerted by the air molecules on the wall of the tires. Therefore, it helps to balance the pressure from the body by providing equal and opposite pressure. One can use air pumps or air compressors to inflate the tires.
Similarly, in steam engines, pneumatic principles are used. The hot stream exerts pressure on the piston, which drags the train forward.
In the case of an air hammer, the air is necessary to deliver the required pressure. The air is responsible for the piston’s forward and backward movement, which leads to the hammer’s movement.
If you use non-pressurized air, it won’t be possible to move the piston. It is because molecules won’t have enough energy to release the required pressure.
What are the components of an air hammer?
The air hammer tool only operates on the compressed air force generated using an air compressor. There are very few components making the designed straightforward and easy to understand.
It is incredible to create such a high-functionality device with only a few components. It can perform many jobs. Here, we are going to go through each component and section one after another. It will help you to understand the role of each component in the working of the air hammer tool.
Spool
The spool is the component placed at the air inlet point or air hose connected to the air compressor or air tank. It moves side by side to direct the air to different pilot ports of the piston. The spool is responsible for transferring the air force to the piston, which allows the hammer to have motion.
Piston
The piston is a cylindrical chamber in the air hammer. Its upward and downward (back and forth) motion due to the air is responsible for the motion of the hammer. The piston is located in the piston chamber connected to the spool on the one end and the hammer and chisel tips (drill bit) on the other end.
Hammer
Hammer is the part that exerts pressure on the targeted material. The material of the hammer is usually selected according to the work requirement. The hammer completely depends upon the piston for its back and forth motion. Without a piston, it can not move forward or backward.
Hammer Tips and Drill Bit
A single air hammer tool can be used for multiple purposes as per required conditions. You need to change tips or drill bits. The hammer bit is the tip of the hammer that comes in the contact with the surface area of the stone or any material. It is also called a chisel. You must choose tools that provide an option to attach different types of drill bit.
You can employ a chisel tip for cutting a surface as per size requirement. You can use a flat hammer tip for shaping a stone or any other material. Similarly, you can use a “nibble-shaped” drill bit for cutting steel with a smooth finish. A worker can also use Pointed bits to create holes on the metal surface.
Piston Chamber
The piston chamber is a cylinder-shaped area in the air hammer tool where the piston is located. The cylinder is connected to the spool through four internal pipes. It has two grooves that are responsible for exerting high pressure on the spool. The high pressure is necessary to move the spool on either side.
As you can see, there is a close loop system between the spool and piston chamber. The spool transfers pressure to the chamber, which makes the piston move. The piston chamber sends back the pressure to the spool. It keeps going on till there is a high air pressure supply from the inlet or air hose.
Shock Absorption Chamber
The shock absorption chamber plays an important role when the hammer moves back along with the piston movement. It has a port that allows air to enter when the hammer moves forward. When the hammer moves back, the air acts as a cushion and control the reverse motion. It saves the air chisel tool body from damage when the hammer hits it during the reverse motion.
Internal pipes
There are four internal pipes connecting the spool to different parts of the piston chamber cylinder.
1) Internal Pipe 1: Connecting spool to top of the piston
2) Internal Pipe 2: Connecting spool to the bottom of the piston
3) Internal Pipe 3: Connecting one side of the spool to one of the grooves
4) Internal Pipe 4: Connecting another side of the spool to another groove
There is 1 exhaust pipe present in the piston chamber.
In the shock absorption chamber, there is a small opening from where the air enters and leaves.
How to know the detailed working of an air hammer?
The process might appear complex, as we mentioned before. However, we have divided the entire working cycle into multiple stages. It would help the reader to understand how exactly this tool works.
Stage-1: When Compressed Air Flow From the Inlet
When you run the air hammer tool, pressurized air from air compressors enters through the inlet valve. Next to the inlet is the spool where the air reaches.
Through one internal pipe, the spool is connected to the top side of the piston. From that pipe, the air travels from the spool to the top of piston.
Stage-2: When the Piston Moves Downward
As the compressed air flows to the top of piston, it exerts pressure on it, making it move downwards.
With the downward motion of the piston, the air in the bottom of the piston moves out.
For that, there is another internal pipe placed on the lower side of the piston. It gives passage to the air to reach back to the spool.
From spool, it is exhausted in the atmosphere. When the piston goes, the hammer and chisel move down along with it.
With the downward movement of the hammer, air enters the shock absorption chamber through the small opening present on the chamber’s wall.
When the piston goes downward, one of the grooves exerts high pressure on the spool. That makes sure that the spool remains in the same position. It allows a passage to the air to enter on the top of the piston.
As the groove moves down along with the piston, the connection between the spool and groove breaks. At the same time, the groove gets connected to an outlet from where the air in the groove exhausts.
Stage-3: When the Piston Moves Upward
After the piston completely moves downward, its upward motion starts again. It happens because the air enters at the bottom of the piston. This time, pressurized air travels through the internal piper, which connects the piston’s spool and bottom side.
Simultaneously, the air above the piston is exhausted through the internal pipe by which it entered. It allows the compressed air present in the bottom to exert air pressure on the piston making it move upward.
Here, another groove plays the role. When the piston is moving back to the upward position, the groove gets connected to the spool. It pushes the spool on the other side with the high air pressure. This facilitates the upward motion of the piston.
The air which entered through the small opening in the shock absorption chamber moves out from the same opening.
The spool valve and piston continuously follow this process till the air supply from the air compressor unit or air tank is provided. Such cycles are repeated numerous times per minute.
What are the safety precautions to follow while using this tool?
Because of the piston movement, there will be a recoil reaction. Therefore, your hands may experience jerks. It is essential to make sure your hands steady and firm to have control while working with jack hammers.
Please make sure to wear safety glasses while using power tools. While using power hand held hammers equipment, small size metal and stone pieces or dust can cause an injury. Safety glasses will keep you safe from them.
Most hand held pneumatic hammers and similar power tools produce loud noises due to piston movement, hammer movement, and the hammer striking on the metal or stone. Therefore, good quality earplugs are required to have safety from the noise. Also, make sure to cut the compressed air supply from the compressor while changing hammer tips.
Tips to follow while using an air hammer
- Use the right amount of pressure. Too much pressure can damage the hammer’s body. However, when the pressure is too low, it won’t be able to move the spool.
- You should continuously pour water on the working material. It will help to reduce the dust and also provides a long life to your drill bit.
- Clear the flutes around the drill bit flutes at regular internals between the hammering process. It will ensure the proper functioning to obtain the desired results.
Conclusion
A jack hammer tool operates on a very simple mechanism that works using air pressurized through air compression.
The mechanism defines the base to pneumatics hammers. With time, it has been developed to deliver high-speed motion. In addition to that, people have even experimented with the hammer shape, size, and material. If someone asks you how does an air hammer work, you can reply, “spool-piston mechanism.” It’s nothing but the coordination between spool and piston by the movement of compressed air. The complete mechanism works to provide continuous back and forth motion to the hammer.
