Skid-steer

A skid loader, skid-steer loader, or skidsteer, is a small, rigid-frame, engine-powered machine with lift arms used to attach a wide variety of labor-saving tools or attachments.

Skid-steer loaders are typically four-wheel vehicles with the wheels mechanically locked in synchronization on each side, and the left-side drive wheels can be driven independently of the right-side drive wheels. The wheels typically have no separate steering mechanism and hold a fixed straight alignment on the body of the machine. By operating the left and right wheel pairs at different speeds, the machine turns by skidding, or dragging its fixed-orientation wheels across the ground. The extremely rigid frame and strong wheel bearings prevent the torsional forces caused by this dragging motion from damaging the machine. As with tracked vehicles, the high ground friction produced by skid steers can rip up soft or fragile road surfaces. They can be converted to low ground friction by using specially designed wheels such as the Mecanum wheel. Skid-steer loaders are capable of zero-radius, "pirouette" turning, which makes them extremely maneuverable and valuable for applications that require a compact, agile loader. Skid-steer loaders are sometimes equipped with tracks in lieu of the wheels and such a vehicle is known as a multi terrain loader.

Unlike in a conventional front loader, the lift arms in these machines are alongside the driver with the pivot points behind the driver's shoulders. Because of the operator's proximity to moving booms, early skid loaders were not as safe as conventional front loaders, particularly during entry and exit of the operator. Modern skid loaders have fully enclosed cabs and other features to protect the operator. Like other front loaders, it can push material from one location to another, carry material in its bucket or load material into a truck or trailer.

The first three-wheeled, front-end loader was invented by brothers Cyril and Louis Keller in Rothsay, Minnesota, in 1957. The Kellers built the loader to help a farmer mechanize the process of cleaning turkey manure from his barn. The light and compact machine, with its rear caster wheel, was able to turn around within its own length, while performing the same tasks as a conventional front-end loader.

The Melroe brothers, of Melroe Manufacturing Company in Gwinner, N.D., purchased the rights to the Keller loader in 1958 and hired the Kellers to continue refining their invention. As a result of this partnership, the M-200 Melroe self-propelled loader was introduced at the end of 1958. It featured two independent front-drive wheels and a rear caster wheel, a 12.9-hp engine and a 750-lb. lift capacity. Two years later they replaced the caster wheel with a rear axle and introduced the M-400, the first four-wheel, true skid-steer loader. The M-440 was powered by a 15.5-hp engine and had an 1100-lb. rated operating capacity. Skid-steer development continued into the mid-1960s with the M600 loader.

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