A lawn mower (mower, etc.) is a machine utilizing one or more revolving
blades to cut a grass surface to an even height. The height of the cut grass may be fixed by the design of the mower, but generally is adjustable by the operator, typically by a single master lever, or by a lever or nut and bolt on each of the machine's wheels. The blades may be powered by muscle, with wheels mechanically connected to the cutting blades so that when the mower is pushed forward, the blades spin, or the machine may have a battery-powered or plug-in electric motor. The most common power source for lawn mowers is a small (typically one cylinder) internal combustion engine, particularly for larger, self-propelled mowers. Smaller mowers often lack any form of propulsion, requiring human power to move over a surface; "walk-behind" mowers are self-propelled, requiring a human only to walk behind and guide them. Larger lawn mowers are usually either self-propelled "walk-behind" types, or more often, are "ride-on" mowers, equipped so the operator can ride on the mower and control it. A robotic lawn mower ("lawn-mowing bot", "mowbot", etc.) is designed to operate either entirely on its own, or less commonly by an operator by remote control.
Many lawn mowers include other functions such as mulching the cut grass or collecting their grass clippings in a removable bag or bin.
Two main styles of blades are used in lawn mowers. Lawn mowers employing a single blade that rotates about a single vertical axis are known as rotary mowers, while those employing a cutting bar and multiple blade assembly that rotates about a single horizontal axis are known as cylinder or reel mowers (although in some versions, the cutting bar is the only blade, and the rotating assembly consists of flat metal pieces which force the blades of grass against the sharp cutting bar).
There are several types of mowers, each suited to a particular scale and purpose. The smallest types, unpowered push mowers, are suitable for small residential lawns and gardens. Electrical or piston engine-powered push-mowers are used for larger residential lawns (although there is some overlap). Riding mowers, which sometimes resemble small tractors, are larger than push mowers and are suitable for large lawns, although commercial riding lawn mowers (such as zero-turn mowers) can be "stand-on" types, and often bear little resemblance to residential lawn tractors, being designed to mow large areas at high speed in the shortest time possible. The largest multi-gang (multi-blade) mowers are mounted on tractors and are designed for large expanses of grass such as golf courses and municipal parks, although they are ill-suited for complex terrain requiring maneuverability.
A transition from traditional hand-guided or ride-on mowers to automatic electric mowers is beginning to take place in some regions, with the growth in robotic lawn mower sales of 2012 being 15 times the growth in sales of the traditional styles. At current rates of growth automated lawn mowers may soon outsell traditional mowers in those regions.
The first lawn mower was invented by Edwin Budding in 1830 in Thrupp, just outside Stroud, in Gloucestershire, England. Budding's mower was designed primarily to cut the grass on sports grounds and extensive gardens, as a superior alternative to the scythe, and was granted a British patent on August 31, 1830.
An early cylinder (reel) mower, showing a fixed cutting blade in front of the rear roller and wheel-driven rotary blades.
Budding's first machine was 19 inches (480 mm) wide with a frame made of wrought iron. The mower was pushed from behind. Cast iron gear wheels transmitted power from the rear roller to the cutting cylinder, allowing the rear roller to drive the knives on the cutting cylinder; the ratio was 16:1. Another roller placed between the cutting cylinder and the main or land roller could be raised or lowered to alter the height of cut. The grass clippings were hurled forward into a tray-like box. It was soon realized, however, that an extra handle was needed in front to help pull the machine along. Overall, these machines were remarkably similar to modern mowers.
Rotary mowers can throw out debris with extreme velocity and energy. Additionally, the blades of a self-powered push mower (gasoline or electric) can injure a careless or inattentive user; as such, many come equipped with a dead man's switch to immediately disable the blade rotation when the user is no longer holding the handle. In the United States, over 12,000 people per year are hospitalized as a result of lawn mower accidents. The vast majority of these injuries can be prevented by wearing protective footwear when mowing. The American Academy of Pediatrics recommends that children be at least 12 years old before they are allowed to use a walk-behind lawn mower and at least 16 years of age before using a riding mower. They also should demonstrate proper judgment and maturity. Persons using a mower should wear heavy footwear, eye protection, and hearing protection in the case of engine-powered mowers.
A 2001 study showed that some mowers produce the same amount of pollution (emissions other than carbon dioxide) in one hour as driving a 1992 model vehicle for 650 miles (1,050 km). Another estimate puts the amount of pollution from a lawn mower at four times the amount from a car, per hour, although this report is no longer available. Beginning in 2011, the United States Environmental Protection Agency set standards for lawn equipment emissions and expects a reduction of at least 35 percent.
Mowers also create significant noise pollution, and could cause hearing loss if used without hearing protection. This can be avoided through the use of reel mowers or by using cheap, easily obtainable hearing protection such as earplugs or earmuffs.
Many lawn mowers include other functions such as mulching the cut grass or collecting their grass clippings in a removable bag or bin.
Two main styles of blades are used in lawn mowers. Lawn mowers employing a single blade that rotates about a single vertical axis are known as rotary mowers, while those employing a cutting bar and multiple blade assembly that rotates about a single horizontal axis are known as cylinder or reel mowers (although in some versions, the cutting bar is the only blade, and the rotating assembly consists of flat metal pieces which force the blades of grass against the sharp cutting bar).
There are several types of mowers, each suited to a particular scale and purpose. The smallest types, unpowered push mowers, are suitable for small residential lawns and gardens. Electrical or piston engine-powered push-mowers are used for larger residential lawns (although there is some overlap). Riding mowers, which sometimes resemble small tractors, are larger than push mowers and are suitable for large lawns, although commercial riding lawn mowers (such as zero-turn mowers) can be "stand-on" types, and often bear little resemblance to residential lawn tractors, being designed to mow large areas at high speed in the shortest time possible. The largest multi-gang (multi-blade) mowers are mounted on tractors and are designed for large expanses of grass such as golf courses and municipal parks, although they are ill-suited for complex terrain requiring maneuverability.
A transition from traditional hand-guided or ride-on mowers to automatic electric mowers is beginning to take place in some regions, with the growth in robotic lawn mower sales of 2012 being 15 times the growth in sales of the traditional styles. At current rates of growth automated lawn mowers may soon outsell traditional mowers in those regions.
The first lawn mower was invented by Edwin Budding in 1830 in Thrupp, just outside Stroud, in Gloucestershire, England. Budding's mower was designed primarily to cut the grass on sports grounds and extensive gardens, as a superior alternative to the scythe, and was granted a British patent on August 31, 1830.
An early cylinder (reel) mower, showing a fixed cutting blade in front of the rear roller and wheel-driven rotary blades.
Budding's first machine was 19 inches (480 mm) wide with a frame made of wrought iron. The mower was pushed from behind. Cast iron gear wheels transmitted power from the rear roller to the cutting cylinder, allowing the rear roller to drive the knives on the cutting cylinder; the ratio was 16:1. Another roller placed between the cutting cylinder and the main or land roller could be raised or lowered to alter the height of cut. The grass clippings were hurled forward into a tray-like box. It was soon realized, however, that an extra handle was needed in front to help pull the machine along. Overall, these machines were remarkably similar to modern mowers.
Rotary mowers can throw out debris with extreme velocity and energy. Additionally, the blades of a self-powered push mower (gasoline or electric) can injure a careless or inattentive user; as such, many come equipped with a dead man's switch to immediately disable the blade rotation when the user is no longer holding the handle. In the United States, over 12,000 people per year are hospitalized as a result of lawn mower accidents. The vast majority of these injuries can be prevented by wearing protective footwear when mowing. The American Academy of Pediatrics recommends that children be at least 12 years old before they are allowed to use a walk-behind lawn mower and at least 16 years of age before using a riding mower. They also should demonstrate proper judgment and maturity. Persons using a mower should wear heavy footwear, eye protection, and hearing protection in the case of engine-powered mowers.
A 2001 study showed that some mowers produce the same amount of pollution (emissions other than carbon dioxide) in one hour as driving a 1992 model vehicle for 650 miles (1,050 km). Another estimate puts the amount of pollution from a lawn mower at four times the amount from a car, per hour, although this report is no longer available. Beginning in 2011, the United States Environmental Protection Agency set standards for lawn equipment emissions and expects a reduction of at least 35 percent.
Mowers also create significant noise pollution, and could cause hearing loss if used without hearing protection. This can be avoided through the use of reel mowers or by using cheap, easily obtainable hearing protection such as earplugs or earmuffs.
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