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A jackhammer (pneumatic drill or demolition hammer in British English) is a pneumatic or electro-mechanical tool that combines a hammer directly with a chisel. It was invented by William Mcreavy, who then sold the patent to Charles Brady King.[1] Hand-held jackhammers are generally powered by compressed air, but some are also powered by electric motors. Larger jackhammers, such as rig-mounted hammers used on construction machinery, are usually hydraulically powered. Jackhammers are typically used to break up rock, pavement, and concrete.

A jackhammer operates by driving an internal hammer up and down. The hammer is first driven down to strike the back and then back up to return the hammer to the original position to repeat the cycle. The effectiveness of the jackhammer is dependent on how much force is applied to the tool. It is generally used like a hammer to break the hard surface or rock in construction works and it is not considered under earth moving equipment, along with its accessories (i.e., pusher leg, lubricator).

In British English, electromechanical versions are colloquially known as "Kangos".

History

The first steam-powered drill was patented by Samuel Miller in 1806. This drill used steam only for raising the drill.[2] Pneumatic drills were developed in response to the needs of mining, quarrying, excavating, and tunneling. A pneumatic drill was proposed by a C. Brunton in 1844.[3][4] In 1846 a percussion drill that could be worked by steam or atmospheric pressure obtained from a vacuum was patented in Britain by Thomas Clarke, Mark Freeman, and John Varley.[5] The first American "percussion drill" was made in 1848 and patented in 1849 by Jonathan J. Couch of Philadelphia, Pennsylvania.[6] In this drill, the drill bit passed through the piston of a steam engine. The piston snagged the drill bit and hurled it against the rock face. It was an experimental model. In 1849, Couch's assistant, Joseph W. Fowle, filed a patent caveat for a percussion drill of his own design. In Fowle's drill, the drill bit was connected directly to the piston in the steam cylinder; specifically, the drill bit was connected to the piston's crosshead. The drill also had a mechanism for turning the drill bit around its axis between strokes and for advancing the drill as the hole deepened.[7] By 1850 or 1851, Fowle was using compressed air to drive his drill, making it the first true pneumatic drill.[8]

The demand for pneumatic drills was driven especially by miners and tunnelers, because steam engines needed fires to operate and the ventilation in mines and tunnels was inadequate to vent the fires' fumes; there was also no way to convey steam over long distances, e.g., from the surface to the bottom of a mine; and mines and tunnels occasionally contained flammable explosive gases such as methane. By contrast, compressed air could be conveyed over long distances without loss of its energy, and after the compressed air had been used to power equipment, it could ventilate a mine or tunnel.

In Europe since the late 1840s, the king of Sardinia, Carlo Alberto, had been contemplating the excavation of a 12-kilometer (7.5 mi) tunnel through Mount Fréjus to create a rail link between Italy and France, which would cross his realm.[9][10] The need for a mechanical rock drill was obvious and this sparked research on pneumatic rock drills in Europe. A Frenchman, Cavé, designed, and in 1851 patented, a rock drill that used compressed air; but the air had to be admitted manually to the cylinder during each stroke, so it was not successful.[11] In 1854, in England, Thomas Bartlett made and then patented (1855) a rock drill whose drill bit was connected directly to the piston of a steam engine. In 1855 Bartlett demonstrated his drill, powered by compressed air, to officials of the Mount Fréjus tunnel project.[12] (In 1855, a German, Schumann, invented a similar pneumatic rock drill in Freiburg, Germany.[13]) Bartlett’s drill was refined by the Savoy-born engineer Germain Sommeiller (1815-1871) and his colleagues, Grandis and Grattoni, by 1861.[14] Thereafter, many inventors refined the pneumatic drill.[15] Sommeiller took his drill to the lengthy Gotthard Pass Tunnel then being built to link railways between Switzerland and Italy under the Alps. Atlas Copco and Ingersoll Rand were two important drill companies in Europe and America respectively, each holding patents and dominating the industry. From this mining and railway tunnelling expanded.

Terminology

The word "jackhammer" is used in North American English and Australia, while "pneumatic drill" is used colloquially elsewhere in the English speaking world, although strictly speaking a "pneumatic drill" refers to a pneumatically driven jackhammer.[16]

In Britain, electromechanical versions are colloquially known as "Kangos".[17][self-published source?] The term comes from the former British brand name now owned by Milwaukee tools.

Use

A Wacker Neuson gasoline-powered breaker on a demolition site

A full-sized portable jackhammer is impractical for use against walls and steep slopes, except by a very strong person, as the user would have to both support the weight of the tool, and push the tool back against the work after each blow. A technique developed by experienced workers is a two-man team to overcome this obstacle of gravity: one operates the hammer and the second assists by holding the hammer either on his shoulders or cradled in his arms. Both use their combined weight to push the bit into the workface. This method is commonly referred to as horizontal jackhammering.

Another method is overhead jackhammering, requiring strength conditioning and endurance to hold a smaller jackhammer, called a rivet buster, over one's head. To make overhead work safer, a platform can be used. One such platform is a positioner–actuator–manipulator (PAM). This unit takes all the weight and vibration from the user.

Types

Pneumatic

A compressor for running a pneumatic jackhammer

A pneumatic jackhammer, also known as a pneumatic drill or pneumatic hammer,[18] is a jackhammer that uses compressed air as the power source. The air supply usually comes from a portable air compressor driven by a diesel engine. Reciprocating compressors were formerly used. The unit comprised a reciprocating compressor driven, through a centrifugal clutch, by a diesel engine. The engine's governor provided only two speeds:

  • idling, when the clutch was disengaged
  • maximum, when the clutch was engaged and the compressor was running

Modern versions use rotary compressors and have more sophisticated variable governors. The unit is usually mounted on a trailer and sometimes includes an electrical generator to supply lights or electric power tools.

Additionally, some users of pneumatic jackhammers may use a pneumatic lubricator which is placed in series with the air hose powering the air hammer. This increases the life and performance of the jackhammer.

Electro mechanical or electropneumatic

A single-phase demolition breaker

An electropneumatic hammer is often called a rotary hammer, because it has an electric motor, which rotates a crank. The hammer has two pistons – a drive piston and a free flight piston. The crank moves the drive piston back and forth in the same cylinder as the flight piston. The drive piston never touches the flight piston. Instead the drive piston compresses air in the cylinder, which then propels the flight piston against a striker, which contacts the drill bit.[19]

Electric powered tools come in a variety of sizes, about 12–65 lb (5.4–29.5 kg). They require an external power source, but do not require a compressor. Although in the past these tools did not have the power of an air or pneumatic hammer, this is changing with newer brushless-motor tools coming close to the power of a pneumatic tool and in some cases even matching it. Electric powered tools are useful for locations where access to a compressor is limited or impractical, such as inside a building, in a crowded construction site, or in a

A jackhammer operates by driving an internal hammer up and down. The hammer is first driven down to strike the back and then back up to return the hammer to the original position to repeat the cycle. The effectiveness of the jackhammer is dependent on how much force is applied to the tool. It is generally used like a hammer to break the hard surface or rock in construction works and it is not considered under earth moving equipment, along with its accessories (i.e., pusher leg, lubricator).

In British English, electromechanical versions are colloquially known as "Kangos".

The first steam-powered drill was patented by Samuel Miller in 1806. This drill used steam only for raising the drill.[2] Pneumatic drills were developed in response to the needs of mining, quarrying, excavating, and tunneling. A pneumatic drill was proposed by a C. Brunton in 1844.[3][4] In 1846 a percussion drill that could be worked by steam or atmospheric pressure obtained from a vacuum was patented in Britain by Thomas Clarke, Mark Freeman, and John Varley.[5] The first American "percussion drill" was made in 1848 and patented in 1849 by Jonathan J. Couch of Philadelphia, Pennsylvania.[6] In this drill, the drill bit passed through the piston of a steam engine. The piston snagged the drill bit and hurled it against the rock face. It was an experimental model. In 1849, Couch's assistant, Joseph W. Fowle, filed a patent caveat for a percussion drill of his own design. In Fowle's drill, the drill bit was connected directly to the piston in the steam cylinder; specifically, the drill bit was connected to the piston's crosshead. The drill also had a mechanism for turning the drill bit around its axis between strokes and for advancing the drill as the hole deepened.[7] By 1850 or 1851, Fowle was using compressed air to drive his drill, making it the first true pneumatic drill.[8]

The demand for pneumatic drills was driven especially by miners and tunnelers, because steam engines needed fires to operate and the ventilation in mines and tunnels was inadequate to vent the fires' fumes; there was also no way to convey steam over long distances, e.g., from the surface to the bottom of a mine; and mines and tunnels occasionally contained flammable explosive gases such as methane. By contrast, compressed air could be conveyed over long distances without loss of its energy, and after the compressed air had been used to power equipment, it could ventilate a mine or tunnel.

In Europe since the late 1840s, the king of Sardinia, Carlo Alberto, had been contemplating the excavation of a 12-kilometer (7.5 mi) tunnel through Mount Fréjus to create a rail link between Italy and France, which would cross his realm.[9][10] The need for a mechanical rock drill was obvious and this sparked research on pneumatic rock drills in Europe. A Frenchman, Cavé, designed, and in 1851 patented, a rock drill that used compressed air; but the air had to be admitted manually to the cylinder during each stroke, so it was not successful.[11] In 1854, in England, Thomas Bartlett made and then patented (1855) a rock drill whose drill bit was connected directly to the piston of a steam engine. In 1855 Bartlett demonstrated his drill, powered by compressed air, to officials of the Mount Fréjus tunnel project.[12] (In 1855, a German, Schumann, invented a similar pneumatic rock drill in Freiburg, Germany.[13]) Bartlett’s drill was refined by the Sa

The demand for pneumatic drills was driven especially by miners and tunnelers, because steam engines needed fires to operate and the ventilation in mines and tunnels was inadequate to vent the fires' fumes; there was also no way to convey steam over long distances, e.g., from the surface to the bottom of a mine; and mines and tunnels occasionally contained flammable explosive gases such as methane. By contrast, compressed air could be conveyed over long distances without loss of its energy, and after the compressed air had been used to power equipment, it could ventilate a mine or tunnel.

In Europe since the late 1840s, the king of Sardinia, Carlo Alberto, had been contemplating the excavation of a 12-kilometer (7.5 mi) tunnel through Mount Fréjus to create a rail link between Italy and France, which would cross his realm.[9][10] The need for a mechanical rock drill was obvious and this sparked research on pneumatic rock drills in Europe. A Frenchman, Cavé, designed, and in 1851 patented, a rock drill that used compressed air; but the air had to be admitted manually to the cylinder during each stroke, so it was not successful.[11] In 1854, in England, Thomas Bartlett made and then patented (1855) a rock drill whose drill bit was connected directly to the piston of a steam engine. In 1855 Bartlett demonstrated his drill, powered by compressed air, to officials of the Mount Fréjus tunnel project.[12] (In 1855, a German, Schumann, invented a similar pneumatic rock drill in Freiburg, Germany.[13]) Bartlett’s drill was refined by the Savoy-born engineer Germain Sommeiller (1815-1871) and his colleagues, Grandis and Grattoni, by 1861.[14] Thereafter, many inventors refined the pneumatic drill.[15] Sommeiller took his drill to the lengthy Gotthard Pass Tunnel then being built to link railways between Switzerland and Italy under the Alps. Atlas Copco and Ingersoll Rand were two important drill companies in Europe and America respectively, each holding patents and dominating the industry. From this mining and railway tunnelling expanded.

The word "jackhammer" is used in North American English and Australia, while "pneumatic drill" is used colloquially elsewhere in the English speaking world, although strictly speaking a "pneumatic drill" refers to a pneumatically driven jackhammer.[16]

In Britain, electromechanical versions are colloquially known as "Kangos".[17]<

In Britain, electromechanical versions are colloquially known as "Kangos".[17][self-published source?] The term comes from the former British brand name now owned by Milwaukee tools.

A full-sized portable jackhammer is impractical for use against walls and steep slopes, except by a very strong person, as the user would have to both support the weight of the tool, and push the tool back against the work after each blow. A technique developed by experienced workers is a two-man team to overcome this obstacle of gravity: one operates the hammer and the second assists by holding the hammer either on his shoulders or cradled in his arms. Both use their combined weight to push the bit into the workface. This method is commonly referred to as horizontal jackhammering.

Another method is overhead jackhammering, requiring strength conditioning and endurance to hold a smaller jackhammer, called a rivet buster, over one's head. To make overhead work safer, a platform can be used. One such platform is a positioner–actuator–manipulator (PAM). This unit takes all the weight and vibration from the user.

Types

Pneumatic

Another method is overhead jackhammering, requiring strength conditioning and endurance to hold a smaller jackhammer, called a rivet buster, over one's head. To make overhead work safer, a platform can be used. One such platform is a positioner–actuator–manipulator (PAM). This unit takes all the weight and vibration from the user.

A pneumatic jackhammer, also known as a pneumatic drill or pneumatic hammer,[18] is a jackhammer that uses compressed air as the power source. The air supply usually comes from a portable air compressor driven by a diesel engine. Reciprocating compressors were formerly used. The unit comprised a reciprocating compressor driven, through a centrifugal clutch, by a diesel engine. The engine's governor provided only two speeds:

  • idling, when the clutch was disengaged
  • maximum, when the clutch was engaged and the compressor was running

Modern versions use rotary compressors and have more sophisticated variable governors. The unit is usually mounted on a trailer and sometimes includes an electrical generator to supply lights or electric power tools.

Additionally, some users of pneumatic jackhammers may use a pneumatic lubricator which is placed in series with the air hose powering the air hammer. This increases the life and performance of the jackhammer.

Electro mechanical or electropneumatic

rotary compressors and have more sophisticated variable governors. The unit is usually mounted on a trailer and sometimes includes an electrical generator to supply lights or electric power tools.

Additionally, some users of pneumatic jackhammers may use a pneuma

Additionally, some users of pneumatic jackhammers may use a pneumatic lubricator which is placed in series with the air hose powering the air hammer. This increases the life and performance of the jackhammer.

An electropneumatic hammer is often called a rotary hammer, because it has an electric motor, which rotates a crank. The hammer has two pistons – a drive piston and a free flight piston. The crank moves the drive piston back and forth in the same cylinder as the flight piston. The drive piston never touches the flight piston. Instead the drive piston compresses air in the cylinder, which then propels the flight piston against a striker, which contacts the drill bit.[19]

Electric powered tools come in a variety of sizes, about 12–65 lb (5.4–29.5 kg). They require an external power source, but do not require a compressor. Although in the past these tools did not have the power of an air or pneumatic hammer, this is changing with newer brushless-motor tools coming close to the power of a pneumatic tool and in some cases even matching it. Electric powered tools are useful for locations where access to a compressor is limited or impractical, such as inside a building, in a crowded construction site, or in a remote location and it is not uncommon under earth moving equipment or tool.

Electropneumatic tools use a variety of chucks for attaching chisels, but the most common are SDS-max, 7/8 in hex, TE-S, and 1+1/8 in hex. The connection end size is also related to the breaking energy of the tool. For example, the Bosch and Hilti 12 lb (5.4 kg) tools both use SDS-max, while the Bosch, Hilti, and Makita 65 lb (29 kg) tools all use 1+1/8 in hex connection. See hammer drills for more on electropneumatic hammering.

Hydraulic