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آلات کارگاهی (انگلیسی)
Dump
trucks
Dump trucks or production trucks
are those that are used for transporting loose material such as sand,
dirt, and gravel for construction.
The typical dump truck is equipped with a hydraulically operated open
box bed hinged at the rear, with the front being able to be lifted up to
allow the contents to fall out on the ground at the site of
delivery.Dump trucks come in many different configurations with each one
specified to accomplish a specific task in the construction chain.
Standard dump truck
The standard dump truck is a full truck chassis with the dump
body mounted onto the frame. The dump body is raised by a hydraulic ram
lift that is mounted forward of the front bulkhead, normally between the
truck cab and the dump body. The standard dump truck also has one front
axle, and one or more rear axles which normally has dual wheels on each
side. The common configurations for standard dump trucks include the
six wheeler and ten wheeler.
Transfer dump truck
For the amount of noise made when transferring, the transfer
dump truck is easy to recognize. It’s a standard dump truck that pulls a
separate trailer which can be loaded with sand, asphalt, gravel, dirt,
etc. The B box or aggregate container on the trailer is
powered
by an electric motor and rides on wheels and rolls off of the trailer
and into the main dump box. The biggest advantage with this
configuration is to maximize payload capacity without having to
sacrifice the maneuverability of the short and nimble dump truck
standards.
Semi trailer end dump
truck
The semi end dump truck is a tractor trailer
combination where the trailer itself contains the hydraulic hoist. The
average semi end dump truck has a 3 axle tractor that pulls a 2 axle
semi trailer. The advantage to having a semi end dump truck is rapid
unloading.
Semi trailer bottom
dump truck
A bottom dump truck is a 3 axle tractor that
pulls a 2 axle trailer with a clam shell type dump gate in the belly of
the trailer. The biggest advantage of a semi bottom dump truck is the
ability to lay material in a wind row. This type of truck is also
maneuverable in reverse as well, unlike the double and triple trailer
configurations.
Double and triple
trailer
The double and triple bottom dump trucks consist
of a 2 axle tractor pulling a semi axle semi trailer and an additional
trailer. These types of dump trucks allow the driver to lay material in
wind rows without having to leave the cab or stop the truck. The biggest
disadvantage is the difficulty in going in reverse.
Side dump trucks
Side dump trucks consist of a 3 axle trailer pulling a 2 axle
semi trailer. It offers hydraulic rams that tilt the dump body onto the
side, which spills the material to the left or right side of the
trailer. The biggest advantages with these types of dump trucks are that
they allow rapid unloading and carry more weight than other dump
trucks.
In addition to this, side dump
trucks are almost impossible to tip over while dumping, unlike the semi
end dump trucks which are very prone to being upset or tipped over. The
length of these trucks impede maneuverability and limit versatility.
Off road dump trucks
Off road trucks resemble heavy construction equipment more
than they do highway dump trucks. They are used strictly for off road
mining and heavy dirt hauling jobs, such as excavation work. They are
very big in size, and perfect for those time when you need to dig out
roads and need something to haul the massive amounts of dirt to another
location.
Front
loaders
Also known as a front end loader,
bucket loader, scoop loader, or shovel, the front loader is a type of
tractor that is normally wheeled and uses a wide square tilting bucket
on the end of movable arms to lift and move material around.The loader
assembly may be a removable attachment or permanently mounted on the
vehicle. Often times, the bucket can be replaced with other devices or
tools, such as forks or a hydraulically operated bucket.
Larger style front loaders, such
as the Caterpillar 950G or the Volvo L120E, normally have only a front
bucket and are known as front loaders, where the small front loaders are
often times equipped with a small backhoe as well and called backhoe
loaders or loader backhoes.Loaders are primarily used for loading
materials into trucks, laying pipe, clearing rubble, and also digging.
Loaders aren’t the most efficient machines for digging, as they can’t
dig very deep below the level of their wheels, like the backhoe can.
The deep bucket on the front
loader can normally store around 3 – 6 cubic meters of dirt, as the
bucket capacity of the loader is much bigger than the bucket capacity of
a backhoe loader. Loaders aren’t classified as excavating machinery, as
their primary purpose is other than moving dirt.In construction areas,
mainly when fixing roads in the middle of the city, front loaders are
used to transport building materials such as pipe, bricks, metal bars,
and digging tools. Front loaders are also very useful for snow removal
as well, as you can use their bucket or as a snow plow. They can clear
snow from the streets and highways, even parking lots.They will
sometimes load the snow into dump trucks which will then haul it away.
Unlike the bulldozer, most loaders
are wheeled and not tracked. The wheels will provide better mobility
and speed and won’t damage paved roads near as much as tracks, although
this will come at the cost of reduced traction. Unlike backhoes or
tractors fitted with a steel bucket, large loaders don’t use automotive
steering mechanisms, as they instead steer by a hydraulically actuated
pivot point set exactly between the front and rear axles.This is known
as articulated steering and will allow the front axle to be solid,
therefore allowing it to carry a heavier weight.
Articulated steering will also
give a reduced turn in radius for a given wheelbase. With the
front wheels and attachment rotating on the same axis, the
operator is able to steer his load in an arc after positioning the
machine, which can come in quite handy. The problem is that when the
machine is twisted to one side and a heavy load is lifted high in the
air, it has a bigger risk of turning over.
This article was submitted by Er. Ankush
Forklift
Sometimes called a forklift truck,
the forklift is a powerful industrial truck that is used to lift and
transport material by steel forks that are inserted under the load.
Forklifts are commonly used to move loads and equipment that is stored
on pallets. The forklift was developed in 1920, and has since become a
valuable piece of equipment in many manufacturing and warehousing
operations.
Types of Forklifts
The most common type of design with forklifts is the counter
balance. Other types of designs include the reach truck and side loader,
both of which are used in environments where the space is at a minimum.
Control and capability
Forklifts are available in many types and different load
capacities. In the average warehouse setting,most forklifts have load
capacities of around five tons. Along with the control to raise and
lower the forks, you can also tilt the mast to compensate for the
tendency of the load to angle the blades towards the ground and risk
slipping it off the forks. The tilt will also provide a limited ability
to operate on ground that isn’t level.There are some variations that
allow you to move the forks and backrest laterally, which allows easier
placement of a load. In addition to this, there are some machines that
offer hydraulic control to move the forks together or further apart,
which removes the need for you to get out of the cab to manually adjust
for a different size load.
Another forklift variation that
is sometimes used in manufacturing facilities, will utilize forklifts
with a clamp attachment that you can open and close around a load,
instead of having to use forks. Products such as boxes, cartons, etc.,
can be moved with the clamp attachment.
Safety
Forklifts
are rated for loads at a specified maximum weight and a specified
forward type center of gravity. All of this information is located on a
nameplate that is provided by the manufacturer and the loads cannot
exceed these specifications. One of the most important aspects of
operating a forklift is the rear wheel steering. Even though this helps
to increase maneuverability in tight cornering situations, it differs
from the traditional experience of a driver with other wheeled vehicles
as there is no caster action. Another critical aspect of the forklift is
the instability. Both the forklift and the load must be considered a
unit, with a varying center of gravity with every movement of the
load.You must never negotiate a turn with a forklift at full speed with a
raised load, as this can easily tip the forklift over.
This article was submitted by – Er. Ankush
Various Types Of Cranes
A crane is a tower or derrick that
is equipped with cables and pulleys that are used to lift and lower
material. They are commonly used in the construction industry and in the
manufacturing of heavy equipment. Cranes for construction are normally
temporary
structures, either fixed to the ground or mounted
on a purpose built vehicle.
They can either be controlled from
an operator in a cab that travels along with the crane, by a push
button pendant control station, or by radio type controls. The crane
operator is ultimately responsible for the safety of the crews and the
crane.
Mobile Cranes
The most basic type of crane
consists of a steel truss or telescopic boom mounted on a mobile
platform, which could be a rail, wheeled, or even on a cat truck. The
boom is hinged at the bottom and can be either raised or lowered by
cables or hydraulic cylinders.
Telescopic Crane
This type of crane offers a boom that consists of a number of
tubes fitted one inside of the other. A hydraulic mechanism extends or
retracts the tubes to increase or decrease the length of the boom.
Tower Crane
The tower crane is a modern form of a balance crane. When fixed
to the ground, tower cranes will often give the best combination of
height and lifting capacity and are also used when constructing tall
buildings.
Truck Mounted Crane
Cranes mounted on a rubber tire truck will provide great
mobility. Outriggers that extend vertically or horizontally are used to
level and stabilize the crane during hoisting.
Rough Terrain Crane
A crane that is mounted on an undercarriage with four rubber
tires, designed for operations off road. The outriggers extend
vertically and horizontally to level and stabilize the crane when
hoisting. These types of cranes are single engine machines where the
same engine is used for powering the undercarriage as it is for powering
the crane. In these types of cranes, the engine is normally mounted in
the undercarriage rather than
in the upper portion.
Loader Crane
A loader crane is a hydraulically powered articulated arm
fitted to a trailer, used to load equipment onto a trailer. The numerous
sections can be folded into a small space when the crane isn’t in use.
Overhead Crane
Also refered to as a suspended crane, this type is normally
used in a factory, with some of them being able to lift very heavy
loads. The hoist is set on a trolley which will move in one direction
along one or two beams, which move at angles to that direction along
elevated or ground level tracks, often mounted along the side of an
assembly area.
In the excavation world, cranes
are used to move equipment or machinery. Cranes can quickly and easily
move machinery into trenches or down steep hills, or even pipe. There
are many types of cranes available, serving everything from excavation
to road work.
Cranes are also beneficial to
building bridges or construction. For many years, cranes have proven to
be an asset to the industry of construction and excavating. Crane
operators make really good money, no matter what type of crane they are
operating.
This article was submitted by Er. Vikrant
Compact
Excavator
The compact hydraulic excavator
can be a tracked or wheeled vehicle with an approximate operating weight
of 13,300 pounds.Normally, it includes a standard backfill blade and
features an independent boom swing. The compact hydraulic excavator is
also known as a mini excavator.
A compact hydraulic excavator is
different from other types of heavy machinery in the sense that all
movement and functions of the machine are accomplished through the
transfer of hydraulic fluid.The work group and blade are activated by
hydraulic fluid acting upon hydraulic cylinders.The rotation and travel
functions are also activated by hydraulic fluid powering hydraulic
motors.
Most types of compact hydraulic
excavators have three assemblies – house, undercarriage, and the work
group.
House
The
house structure contains the compartment for the operator, engine
compartment, hydraulic pump and also the distribution components. The
house structure is attached to the top of the undercarriage via swing
bearing. Along with the work group, them house is able to rotate upon
the undercarriage without limit due to a hydraulic distribution valve
that supplies oil to the undercarriage components.
Undercarriage
The undercarriage of compact excavators consists of rubber or
steel tracks, drive sprockets, rollers,idlers, and associated components
and structures.The undercarriage is also home to the house structure
and the work group.
Work group
The work group consists of the boom, dipper or arm, and
attachment. It is connected to the front of the house structure via a
swinging frame that allows the work group to be hydraulically pivoted
left or right in order to achieve offset digging for trenching parallel
with the tracks.
Independent boom swing
The purpose of the boom swing is for offset digging around
obstacles or along foundations,
walls, and forms. Another
use is for cycling in areas that are too narrow for cab rotation.
Another major advantage of the compact excavator is the independent boom
swing.
Backfill blade
The backfill blade on compact excavators are used for grading,
leveling, backfilling, trenching, and general dozer work. The blade can
also be used to increase the dumping height and digging depth depending
on it’s position in relation to the workgroup.
The most common place you’ll find
compact excavators is in residential dwellings. When digging phone lines
or other things, these pieces of equipment are very common for getting
between houses. Due to their small size, they can fit almost
anywhere.Over the years, the capabilities for compact excavators have
expanded far beyond the tasks of excavation. With hydraulic powered
attachments such as breakers, clamps, compactors and augers, the compact
excavator is used with many other applications and serves as an
effective attachment tool as well. Serving many purposes, the compact
excavator is a great addition to any job that requires the use of
machinery.
This article is submitted by – Er. Vikrant
Bulldozer
The bulldozer is a very powerful
crawler that is equipped with a blade. The term bulldozer is often used
to mean any type of heavy machinery, although the term actually refers
to a tractor that is fitted with a dozer blade. Often times, bulldozers
are large and extremely powerful tracked vehicles. The tracks give them
amazing ground mobility and hold through very rough terrain. Wide tracks
on the other hand, help to distribute the weight of the dozer over
large areas, therefore preventing it from sinking into sandy or muddy
ground.
Bulldozers have great ground hold and a torque
divider that’s designed to convert the power of the engine into dragging
ability, which allows it to use its own weight to push heavy objects
and even remove things from the ground. Take the Caterpillar D9 for
example, it can easily tow tanks that weight more than 70 tons. Due to
these attributes,bulldozers are used to clear obstacles, shrubbery and
remains of structures and buildings.
The blade on a bulldozer is the
heavy piece of metal plate that is installed on the front. The
blade pushes things around. Normally, the blade comes in 3
varieties:
1. A straight blade that is short
and has no lateral curve, no side wings, and can be used
only
for fine grading.
2. A universal blade, or U blade, which
is tall and very curved, and features large side wings to carry more
material around.
3. A combination blade that is
shorter,offers less curvature, and smaller side wings.
Modifications
Over time, bulldozers have been modified to evolve into new
machines that are capable of things the original bulldozers weren’t. A
good example is that loader tractors were created by removing the blade
and substituting a large volume bucket and hydraulic arms which will
raise and lower the bucket, therefore making it useful for scooping up
the earth and loading it into trucks.Other modifications to the original
bulldozer include making it smaller to where it can operate in small
working areas where movement is very limited, such as mining caves and
tunnels. Very small bulldozers are known as calfdozers.
History
The first types of bulldozers were
adapted from farm tractors that were used to plough fields. In order to
dig canals, raise earth dams, and partake in earthmoving jobs, the
tractors were equipped with a thick metal plate in the front. Later on,
this thick metal plate earned the name blade.
The blade of the bulldozer peels
layers of soil and pushes it forward as the tractor advances.The blade
is the heart and soul of the bulldozer, as it was the first accessory to
make full use for excavation type jobs. As the years went by, when
engineers needed equipment to complete larger jobs, companies such as
CAT, Komatsu, John Deere, Case, and JCB started to manufacture large
tracked earthmoving equipment.They were very loud, very large, and very
powerful and therefore earned the nickname “bulldozer”.Over the years,
the bulldozers got bigger, more powerful, and even more sophisticated.
The important improvements include better engines,more reliable drive
trains, better tracks, and even hydraulic arms that will enable more
precise manipulation of the blade and automated controls.As an added
option, bulldozers can come equipped with a rear ripping claw to break
up pavement or loosen rocky soil.The best known manufacturer of
bulldozer is CAT,which has earned a vast reputation for making
tough and durable, yet reliable machines.Even though the
bulldozer started off a modified farmtractor, it rapidly became one of
the most useful pieces of equipment with excavating and construction.
Backhoe
loader
Also referred to as a loader
backhoe, the backhoe loader is an engineering and excavation vehicle
that consists of a tractor, front shovel and bucket and a small backhoe
in the rear end. Due to the small size and versatility, backhoe loaders
are common with small construction projects and excavation type
work.Originally invented in Burlington Iowa back in 1857, the backhoe
loader is the most common variation of the classic farm tractor.As the
name implies, it has a loader assembly on the front and a backhoe
attachment on the back.
Anytime the loader and backhoe are
attached it is never referred to as a tractor, as it is not normally
used for towing and doesn’t normally have a PTO.When the backhoe is
permanently attached, the machine will normally have a seat that can
swivel to the rear to face the backhoe controls.Any type of removable
backhoe attachments will normally have a seperate seat on the attachment
itself.Backhoe loaders are common and can be used for many tasks, which
include construction, light transportation of materials, powering
building equipment, digging holes and excavating, breaking asphalt, and
even paving roads.You can often replace the backhoe bucket with other
tools such as a breaker for breaking and smashing concrete and rock.
There are some loader buckets that offer a retractable bottom, which
enable it to empty the load more quickly and efficiently.
The retractable bottom loader
buckets are often times used for grading and scratching off sand.The
front assembly on a backhoe may be either removable or permanently
attached. Often times,the bucket can be replaced with other tools or
devices. In order to mount different attachments to the loader, it must
be equipped with a tool coupler. The coupler consists of two hydraulic
cylinders on the end of the arm assembly, which can expand and retract
to allow different tools to be attached to the unit. There are several
types of backhoe loader brands,including New Holland, John Deere, and
Case. Some will offer you cabs, while others won’t. The newer types of
backhoe loaders even offer you air conditioning, radios, and other
accessories that make you feel like you are working with luxury.Common
with excavating jobs, the backhoe can serve many purposes. It can haul
equipment and supplies in the loader bucket.Another great use is to
cover up dirt when filling in trench lines or covering up pipe that was
just put in the ground.The backhoe attachment at the rear is ideal for
digging water pipes and sewer pipes.The best thing about the backhoe
loader is the fact that they are easy to operate. You don’t need to be a
rocket scientist to fully operate this nifty piece of equipment.
Submitted By : Er. Vikrant
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