Loader (equipment)
Heavy Equipment Front Loaders
A loader, also called a front loader, front end loader, bucket loader, scoop loader or shovel, is a type of tractor, usually wheeled, that uses a wide square tilting bucket on the end of movable arms to lift and move material.
The loader assembly may be a removable attachment or permanently mounted. Often the bucket can be replaced with other devices or tools--for example, many can mount forks to lift heavy pallets or shipping containers, and a hydraulically-opening "clamshell" bucket allows a loader to act as a light dozer or scraper. The bucket can also be augmented with devices like a bale grappler for handling large bales of hay or straw.
Large loaders, such as the Caterpillar 950G, Volvo L120E, Caterpillar 966G, or Hitachi ZW310 usually have only a front bucket and are called Front Loaders, whereas small loader tractors are often also equipped with a small backhoe and are called backhoe loaders or loader backhoes.
Loaders are used mainly for uploading materials into trucks, laying pipe, clearing rubble, and digging. A loader is not the most efficient machine for digging as it cannot dig very deep below the level of its wheels, like a backhoe can. Their deep bucket can usually store about 3-6 cubic meters (exact number varies with the model) of earth. The front loader's bucket capacity is much bigger than a bucket capacity of a backhoe loader. Loaders are not classified as earthmoving machinery, as their primary purpose is other than earthmoving.
In construction areas loaders are also used to transport building materials - such as bricks, pipe, metal bars, and digging tools - over short distances.
Loaders are also used for snow removal, using their bucket or a snowbasket but usually they use a snowplow attachment (see photo at right). They clear snow from streets and highways and also parking lots. They sometimes load the snow into dump trucks which haul it away
Unlike most bulldozers, some loaders are wheeled and not tracked. However, track loaders do exist. They are successful where sharp edged materials or nails in construction debris would damage rubber wheels. Wheels provide better mobility and speed and do not damage paved roads as much as tracks, but this comes at the cost of reduced traction.
Unlike backhoes or standard tractors fitted with a front bucket, many large loaders do not use automotive steering mechanisms. Instead, they steer by a hydraulically actuated pivot point set exactly between the front and rear axles. This is referred to as "articulated steering" and allows the front axle to be solid, allowing it to carry a heavier weight. Articulated steering also gives reduced turning radius (and therefore higher maneuverability) for a given wheelbase. Since the front wheels and attachment rotate on the same axis, the operator is able to "steer" his load in an arc after positioning the machine, which can come in handy. The problem is that when the machine is "twisted" to one side and a heavy load is lifted high, it has a bigger risk of turning over to the "wide" side.
Front loaders gained popularity during the last two decades, especially in urban engineering projects and small earthmoving works. Many engineering vehicle manufacturers offer a wide range of loaders, the most notable are those of Caterpillar, Volvo, Komatsu and Liebherr.
The term "loader" is also used in the debris removal field to describe the boom on a grapple truck.
Compact Front End Loaders
Very popular additions to compact utility tractors and farm tractors are Front End Loaders, also referred to as a FEL. Compact utility tractors, also called CUTs are small tractors, typically with 18 to 50 horsepower and used primarily for ground maintenance and landscape chores. There are 2 primary designs to compact tractor FELs, the traditional dogleg designed style and the curved arm style.
John Deere Tractor manufactures a semi-curved loader design that does not feature the one piece curved arm, but also is not of the traditional two piece design. New Holland Ag introduced a compact loader with a one piece curved arm on its compact utility tractors, similar one piece curved arm loaders are now available on compact tractors on many brands including Case/Farmall, and some Montana and Kioti tractors. Kubota markets traditional loader designs on most of its compact tractors but now features a semi-curved loader design similar to the John Deere loader design on several of its small tractors.
While the Front End Loaders on CUT size tractors are capable do doing their fair share of work, given their relatively small size and low capacities when compared to commercial loaders, the compact loaders can be made more useful with some simple options. A Toothbar is commonly added to the front edge of a loader bucket to aid with digging. Some loaders are equipped with a Quick Attach (QA) system, the QA system allows the bucket to be removed easily and other tools to be added in its place. Common additions would include a set of Pallet Forks for lifting pallets of goods or a Bale Spear for lifting hay bales.
Specifications on Compact Loader capacities are often confusing because the manufacturers do not use the same measurement points to list capacities as the industrial/commercial loader manufacturers use. A typical Compact Loader's capacity is measured at several points and at several heights. Measurements at the pivot points of the loader do not reflect real world load capacities because geometry demands that loads carried farther forward of the fulcrum point (the pivot point on a loader) will be lower than loads carried at the pivot point itself. Some manufacturers provide capacity figures at the pivot point. Others, such as New Holland Ag and Kubota provide capacity at 500mm forward of that point, which means they take their measurement of capacity at a position inside the bucket. Measuring at the 500mm forward point provides a real life capacity to the user, while measuring at the pivot point may mislead the user into believing he has more capacity than the loader can actually lift. Further, when capacity is measured at the full lift height it is lower than if it is measured at 59.5" above the ground, yet many manufacturers are now listing capacity at 59.5" of lift height. Another common measurement height to list capacity is 12" above the ground, which yields even higher lift capacity. Consequently two equal loaders measured by two different manufacturers may have dramatically different reported capacity claims in the marketing brochures.
Skid Loaders & Track Loaders
A skid loader is a small loader utilizing 4 wheels with hydraulic drive that directs power to either, or both, sides of the vehicle. Very similar in appearance and design is the track loader, which utilizes a continuous track on either side of the vehicle instead of the wheels. Since the expiration of Bobcat's patent on it quick-connect system; newer tractor models are standardizing on that popular format for front end attachments.
See also
- Backhoe loader
- Bulldozer
- Crane
- Engineering vehicles
- Excavator
- Grader
- Skid loader
- Tractor
- Telescopic handler