2015

whereas small loader tractors are often also equipped with a small backhoe and are called backhoe loaders or loader backhoes or JCBs, after the company that first claim to have invented them. Other companies like CASE in America and Whitlock in the UK had been manufacturing Excavator Loaders well before JCB.

The largest loader in the world is LeTourneau L-2350. Currently these large loaders are in production in the Longview, Texas facility. The L- 2350 uses a diesel electric propulsion system similar to that used in a locomotive. Each rubber tired wheel is driven by its own independent electric motor.

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. The capacity of a loader bucket can be anywhere from 0.5 to 36 m3 depending upon the size of the machine and its application. The front loader's bucket capacity is generally much bigger than a bucket capacity of a backhoe loader.

Unlike most bulldozers, most loaders are wheeled and not tracked, although track loaders are common. They are successful where sharp edged materials in construction debris would damage rubber wheels, or where the ground is soft and muddy. Wheels provide better mobility and speed and do not damage paved roads as much as tracks, but provide less traction.

З 4.63. , :

1.What is a loader equipped with?

2.What are the loaders used for?

3.What is the difference between a loader and bulldozer?

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ture, power train, control and information. Heavy equipment functions through the mechanical advantage of a simple machine, the ratio between input force applied and force exerted is multiplied. Currently most equipment use hydraulic drives as a primary source of motion

З 4.67. , ,

.

Heavy-duty vehicles and large pieces of machinery are generally referred to as heavy equipment. This term encompasses civil engineering vehicles, utility vehicles from construction equipment to agricultural and forestry implements, and equipment used for heavy hauling, such as railroad cars, semi trucks, trailers, and dump trucks. A piece of heavy equipment is generally designed specifically for one purpose, although some implements

may be used in more than one capacity. Most heavy equipment uses hy-

НrКЮХТМ МШЦpШЧОЧЭs, КЧН ЭШНКв’s НОsТРЧs КrО ЛОМШЦТЧР ОvОЧ ЦШrО rОПТЧОН with advances in technology such as sophisticated electronics. Many modern heavy equipment implements rely on computers to function, and they are maintained using computers that test working parts and report specific problems.

The use of heavy equipment varies in different applications, from civil engineering or infrastructure and military, to other heavy construction

civil engineering applications use implements from large cranes to much smaller tools such as jackhammers. Infrastructure projects often include highway repair and maintenance, bridges and overpasses, and projects such as interstate bypasses.

Heavy construction generally refers to building playgrounds or parks and large buildings such as office complexes or shopping centers. Backhoes, bulldozers, and other earth moving equipment are frequently used to break ground, while cranes are often used to place large beams and framing elements. Agricultural interests include farming, which us-

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es heavy equipment such as tractors, combines, harvesters, and balers. Landscaping may be included in both agricultural and forestry categories, utilizing heavy equipment such as log splitters, tillers, mowers, chippers, and stump pullers.

While advances in technology may make heavy equipment more functional and reliable, they also make caring for individual pieces far more complicated. Sophisticated technology has created a specialized field when it comes to heavy equipment troubleshooting, repair, and maintenance. Few of the people that own or lease these implements can work on them any more. Repairs from the simple to the extensive, and even routine maintenance, must often be provided by specially trained mechanics and technicians.

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–external combustion engine

–chassis

–operational equipment

–operating element

–integral implements

–continuous machine

–mode

–preparatory work

–subgrade

–engineering structure

–soil compaction

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The construction of road and highways basically consists of 3 phases, rough grading (or earthmoving), fine grading (which includes sub-grade preparation), and surfacing, which can include gravel, concrete, asphalt, or any combination of the three. Compaction is also a major element of all road and highway construction. Sufficient compaction of basic fill, gravels, and asphalt will ensure maximum life of the road structure. Operators must be capable of performing their work in a manner that will provide for maximum compaction. Operators who are involved in fine grading operations must be able to grade surfaces to very fine tolerances, requiring great skill as an operator.

This often includes changing the moisture level in the material being compacted. Machines may work to add moisture (water trucks and graders)

or to reduce moisture levels (discs, mixers, graders, etc.). Paving using concrete or asphalt has evolved significantly ovОr ЭСО вОКrs, КЧН ЭШНКв’s

machines can produce large quantities of paved surfaces in record time.

З 4.72. , :

1.What are the phases of road construction?

2.What is surfacing?

3.What types of road-construction machinery do you know?

4.What are different types of road-construction machinery used for?

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Road-construction machinery

Compactor

Hydraulic Truck Cranes

Cranes

Crawler Loaders

Crawler Loader Buckets and Accessories

Crawler Tractors

Dump Trucks

Excavators

Excavator Accessories

Forestry Equipment

Fork lift

Loader Backhoes

Motor Graders

Pavers

Pipelayers

Scrapers

Skid Steer Loaders

Trenchers

Wheel Loaders

Wheel Loaders Buckets and Accessories

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fork-lift car

two-post car lift

.

A car hoist is a device that is used to raise a car up to allow access to underneath the vehicle. Commonly available in one-, twoand four-post styles, a car hoist is often an invaluable tool when working on the bottom of a vehicle. There are hydraulic versions of the car hoist, however, the electric models are the most commonly used types in home garages and shops. Models of the hoist are available in both ramp and chassis mount designs, with each offering its own positive and negative aspects with the chassis mount design offering the most versatility and access to most vehicles.

Many automobile repairs are more easily completed through the use of a car hoist as compared to working without a hoist. By using the car hoist to raise

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the car, access to chassis, exhaust and suspension components is placed within easy reach for the mechanic. The hoist is a heavy-duty device that commonly reaches under the car and connects to specific points on the vehicle's chassis to facilitate supporting the car when raised into the air. By activating an electric motor, the hoist is raised into the air by use of a threaded rod, or a hydraulic pump with hydraulic cylinders. Some older models of the hoist use an air-powered hydraulic cylinder to raise the vehicle.

The early versions of the car hoist used a single hydraulic cylinder to raise the car. This hoist commonly made it difficult to remove and replace entire exhaust systems. The difficulties stemmed from the placement of the cylinder and the chassis support being located in the center of the vehicle.

The four-post, ramp-style of car hoist solved the access problem by having the car be driven onto a pair of ramps that were raised at all four corners. This left the complete underneath of the chassis open. The problem with this type of hoist, however, is that the vehicle is required to sit on the tires, making access to wheels, brakes and shocks difficult.

To remove tires for maintenance, the four-post hoist required a car to be jacked up while on the hoist and placed on support stands. The two-post car hoist solved this problem by using two outboard arms that reach under the vehicle's chassis from the outer edge of the car. This allows the wheels to be removed while the car is in the raised position, as well as maintaining an open access underneath the car. This two-post design is the most commonly used car hoist in personal and commercial garages worldwide.

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