Lawn mower
A lawn mower is a device 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 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 blades may be powered by manual force, with wheels mechanically connected to the cutting blades so that the blades spin when the mower is pushed forward, or the machine may have a battery-powered or plug-in electric motor. The most common self-contained power source for lawn mowers is a small 4-stroke internal combustion engine. Smaller mowers often lack any form of self-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 that the operator can sit on and control. A robotic lawn mower is designed to operate either entirely on its own or less commonly by an operator on a remote control.
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.
There are several types of mowers, each suited to a particular scale and purpose. The smallest types, non-powered push mowers, are suitable for small residential lawns and gardens. Electrical or piston engine-powered push-mowers are used for larger residential lawns. Riding mowers, which sometimes resemble small tractors, are larger than push mowers and are suitable for large lawns. However, commercial riding lawn 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 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.
History
Invention
The lawn mower was invented in 1830 by Edwin Beard Budding of Stroud, 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.Budding's first machine was 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.
Two of the earliest Budding machines sold went to Regent's Park Zoological Gardens in London and the Oxford colleges. In an agreement between John Ferrabee and Edwin Budding dated May 18, 1830, Ferrabee paid the costs of enlarging the small blades, obtained letters of patent and acquired rights to manufacture, sell and license other manufacturers in the production of lawn mowers. Without patent, Budding and Ferrabee were shrewd enough to allow other companies to build copies of their mower under licence, the most successful of these being Ransomes of Ipswich, which began making mowers as early as 1832.
His machine was the catalyst for the preparation of modern-style sporting ovals, playing fields, grass courts, etc. This led to the codification of modern rules for many sports, including for football, lawn bowls, lawn tennis and others.
Further improvements
It took ten more years and further innovations to create a machine that could be drawn by animals, and sixty years before a steam-powered lawn mower was built. In the 1850s, Thomas Green & Son of Leeds introduced a mower called the Silens Messor, which used a chain drive to transmit power from the rear roller to the cutting cylinder. These machines were lighter and quieter than the gear-driven machines that preceded them, although they were slightly more expensive. The rise in popularity of lawn sports helped prompt the spread of the invention. Lawn mowers became a more efficient alternative to the scythe and domesticated grazing animals.Manufacture of lawn mowers took off in the 1860s. By 1862, Ferrabee's company was making eight models in various roller sizes. He manufactured over 5000 machines until production ceased in 1863. The first grass boxes were flat trays but took their present shape in the 1860s. James Sumner of Lancashire patented the first steam-powered lawn mower in 1893. His machine burned petrol and/or paraffin as fuel. These were heavy machines that took several hours to warm up to operating pressure. After numerous advances, these machines were sold by the Stott Fertilizer and Insecticide Company of Manchester and Sumner. The company they both controlled was called the Leyland Steam Motor Company.
Around 1900, one of the best known English machines was the Ransomes' Automaton, available in chain- or gear-driven models. Numerous manufacturers entered the field with petrol engine-powered mowers after the start of the 20th century. In 1902, The first was produced by Ransomes. JP Engineering of Leicester, founded after World War I, produced a range of very popular chain-driven mowers. About this time, an operator could ride behind animals that pulled the large machines. These were the first riding mowers.
The first United States patent for a reel lawn mower was granted to Amariah Hills on January 12, 1868. In 1870, Elwood McGuire of Richmond, Indiana designed a human-pushed lawn mower, which was very lightweight and a commercial success. John Burr patented an improved rotary-blade lawn mower in 1899, with the wheel placement altered for better performance. Amariah Hills went on to found the Archimedean Lawn Mower Co. in 1871.
In the United States, gasoline-powered lawn mowers were first manufactured in 1914 by Ideal Power Mower Co. of Lansing, Michigan, based on a patent by Ransom E. Olds. Ideal Power Mower also introduced the world's first self-propelled, riding lawn tractor in 1922, known as the "Triplex". The roller-drive lawn mower has changed very little since around 1930. Gang mowers, those with multiple sets of blades to cut a wider swath, were built in the United States in 1919 by the Worthington Mower Company.
Atco Ltd and the first motor mower
In the 1920s one of the most successful companies to emerge during this period was Atco, at that time a brand name of Charles H Pugh Ltd. The Atco 'Standard' motor mower, launched in 1921 was an immediate success. Just 900 of the 22-inch-cut machines were made in 1921, each costing £75. Within five years, annual production had accelerated to tens of thousands. Prices were reduced and a range of sizes were available, making the Standard the first truly mass-produced engine-powered mower.Rotary mowers
Rotary mowers were not developed until engines were small enough and powerful enough to run the blades at sufficient speed. Many people experimented with rotary blade mowers in the late 1920s and early 1930s, and Power Specialties Ltd. introduced a gasoline-powered rotary mower. Kut Kwick replaced the saw blade of the "Pulp Saw" with a double-edged blade and a cutter deck, converting the "Pulp Saw" into the first ever out-front rotary mower.One company that produced rotary mowers commercially was the Australian Victa company, starting in 1952. Its mowers were lighter and easier to use than similar ones that had come before. The first Victa mowers were made at Mortlake, an inner suburb of Sydney, by local resident Mervyn Victor Richardson. He made his first model out of scrap in his garage. The first Victa mowers were then manufactured, going on sale on 20 September 1952. The new company, Victa Mowers Pty Ltd, was incorporated on 13 February 1953.
The venture was so successful that by 1958 the company moved to much larger premises in Parramatta Road, Concord, and then to Milperra, by which time the mower incorporated an engine, designed and manufactured by Victa, which was specially designed for mowing, rather than employing a general-purpose engine bought from outside suppliers. Two Victa mowers, from 1958 and 1968 respectively, are held in the collection of the National Museum of Australia. 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.
The hover mower, first introduced by Flymo in 1964, is a form of rotary mower using an air cushion on the hovercraft principle.
Types
By rotation
Cylinder or reel mowers
A cylinder mower or reel mower carries a fixed, horizontal cutting blade at the desired height of cut. Over this is a fast-spinning reel of blades which force the grass past the cutting bar. Each blade in the blade cylinder forms a helix around the reel axis, and the set of spinning blades describes a cylinder.Of all the mowers, a properly adjusted cylinder mower makes the cleanest cut of the grass, and this allows the grass to heal more quickly. The cut of a well-adjusted cylinder mower is straight and definite, as if cut with a pair of scissors. This clean cut promotes healthier, thicker and more resilient lawn growth that is more resistant to disease, weeds and parasites. Lawn cut with a cylinder mower is less likely to result in yellow, white or brown discolouration as a result of leaf shredding. While the cutting action is often likened to that of scissors, it is neither necessary nor desirable for the blades of the spinning cylinder to contact the horizontal cutting bar. When the reel touches the cutting bar the work required by the mower increases dramatically. When the gap between the blades is less than the thickness of the grass blades, a clean cut can still be made without additional friction. When the gap is greater than the thickness of the grass blades, grass will slip through the gap uncut. Reel mowers also have more difficulty mowing over uneven terrain.
There are many variants of the cylinder mower. Push mowers have no engine and are usually used on smaller lawn areas where access is a problem, where noise pollution is undesirable and where air pollution is unwanted. As the mower is pushed along, the wheels drive gears which rapidly spin the reel. Typical cutting widths are. Advances in materials and engineering have resulted in these mowers being very light and easy to operate and manoeuvre compared with their predecessors while still giving all the cutting advantages of professional cylinder mowers. 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.
The basic push mower mechanism is also used in gangs towed behind a tractor. The individual mowers are arranged in a "v" behind the tractor with each mower's track slightly overlapping that of the mower in front of it. Gang mowers are used over large areas of turf such as sports fields or parks.
A gasoline engine or electric motor can be added to a cylinder mower to power the cylinder, the wheels, the roller, or any combination of these. A typical arrangement on electric powered machines for residential lawns is for the motor to power the cylinder while the operator pushes the mower along. The electric models can be corded or cordless. On petrol machines the engine drives both the cylinder and the rear roller. 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. One type of reel mower, now largely obsolete, was a powered version of the traditional side-wheel push mower, which was used on residential lawns. An internal combustion engine sat atop the reel housing and drove the wheels, usually through a belt. The wheels in turn drove the reel, as in the push mower.
Greens mowers are used for the precision cutting of golf greens and have a cylinder made up of at least eight, but normally ten, blades. The machine has a roller before and after the cutting cylinder which smooths the freshly cut lawn and minimizes wheel marks. Due to the weight, the engine also propels the mower. 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.
Riding reel mowers are also produced. Typically, the cutting reels are ahead of the vehicle's main wheels, so that the grass can be cut before the wheels push the grass over onto the ground. The reels are often hydraulically powered.
The main parts of a cylinder or reel mower are:
- Blade reel/cylinder: Consists of numerous helical blades that are attached to a rotating shaft. The blades rotate, creating a scissor-like cutting motion against the bed knife.
- Bed knife: The stationary cutting mechanism of a cylinder/reel mower. This is a fixed horizontal blade that is mounted to the frame of the mower.
- Body frame: The main structural frame of the mower onto which the other parts of the mower are mounted.
- Wheels: Help propel the mower in action. Generally, reel mowers have two wheels.
- Push handle: The "power source" of a manually operated reel mower. This is a sturdy T-shaped, rectangular, or trapezoidal handle that is connected to the frame, wheels and blade chamber.
- Motor: The power source of a reel mower that is powered by gasoline or electricity.