Lawn mower
The height of the cut grass may be fixed by the mower's design but generally is adjustable by the operator, typically by a single master lever or by a mechanism on each of the machine's wheels.
The most common self-contained power source for lawn mowers is a small 4-stroke (typically one-cylinder) internal combustion engine.
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.
[1] 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.
In the 1850s, Thomas Green & Son of Leeds introduced a mower called the Silens Messor (meaning silent cutter), which used a chain drive to transmit power from the rear roller to the cutting cylinder.
[5][6][failed verification] JP Engineering of Leicester, founded after World War I, produced a range of very popular chain-driven mowers.
[12] The Victa mower is regarded as something of an Australian icon, appearing en masse, in simulated form, at the opening of the Sydney Olympic Games in 2000.
This clean cut promotes healthier, thicker and more resilient lawn growth that is more resistant to disease, weeds and parasites.
Their distinct environmental benefits, both in noise and air pollution, are also strong selling points, something not lost on many international zoos, animal sanctuaries and exclusive hotel groups.
Some variants have only three blades in a reel spinning at great speed, and these models are able to cut grass which has grown too long for ordinary push mowers.
Much smaller and lighter variants of the roller mower are sometimes used for small patches of ornamental lawns around flower beds, and these have no engine.
The main parts of a rotary mower are: Extensive grass trimming was not common before the widespread application of the vertical shaft single cylinder gasoline/petrol engine.
The engines usually have a carburetor and require a manual pull crank to start them, although an electric starter is offered on some models, particularly large riding and commercial mowers.
The California bill barred sales of spark ignited (gasoline fueled) internal combustion engines less than 25HP used for farm or construction machines as of January 1, 2024.
[19] The California bill does not ban turf care machines larger than 25HP or those powered by compression ignition (diesel) engines.
There is the additional hazard with these machines of accidentally mowing over the power cable, which stops the mower and may put users at risk of receiving a dangerous electric shock.
Hover mowers are necessarily light in order to achieve the air cushion and typically have plastic bodies with an electric motor.
The most significant disadvantage, however, is the cumbersome usability in rough terrain or on the edges of lawns, as the lifting air-cushion is destroyed by wide gaps between the chassis and the ground.
Hover mowers are built to operate on steep slopes, waterfronts, and high-weeded areas, so they are often used by golf course greenskeepers and commercial landscapers.
The attachments can simply function by the movement of the tractor similar to manual push cylinder mowers, but also sometimes may have powered moving blades.
These are usually designed to resemble a small agricultural tractor, with the cutting deck mounted amidships between the front and rear axles.
There have been a number of attempts to replace hydrostatic transmissions with lower cost alternatives, but these attempts, which include variable belt types, e.g. MTD's "Auto Drive", and toroidal, have various performance or perception problems that have caused their market life to be short or their market penetration to be limited.
Professional grass-cutting equipment, used by large establishments such as universities, sports stadiums and local authorities, usually take the form of much larger, dedicated, ride-on platforms or attachments that can be mounted on, or behind, a standard tractor unit (a "gang-mower").
These extensions can be lowered for large area mowing or raised to decrease the mower's width and allow for easy transport on city roads or trailers.
Commercial lawn-mowing companies have also enthusiastically adopted types such as the zero-turn mower (in both ride-on and stand-on versions), which allow high speed over the grass surface, and rapid turnaround at the end of rows, as well as excellent maneuverability around obstacles.
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).
[31] Beginning in 2011, the United States Environmental Protection Agency set standards for lawn equipment emissions and expects a reduction of at least 35 percent.
A minimum-maintained lawn management practice with clipping recycling, and minimum irrigation and mowing, is recommended to mitigate global warming effects from urban turfgrass system.
[33] Battery-powered lawn mowers offer cleaner alternatives to consumers by producing zero emissions, being more efficient, and eliminating risks of spilled gasoline.
[38] One study assessed the occupational noise exposure among groundskeepers at several North Carolina public universities and found noise levels from push lawn mowers measured between 86 and 95 decibels (A-weighted) and from riding lawn mowers between 88 and 96 dB(A); both types exceeded the National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit of 85 dB(A).
