Plant Machinery

Posts Tagged ‘Loader’

Articulated front end loaders are designed by engineers from the ground up to push hard into earth and lift heavy loads at the front of the loader and also to be extremely versatile in the field.

The following article illustrates 8 points of difference between an articulated front end loader and a front end loader fitted to a tractor generally after purchase.

1. Maneuverability. Articulated front end loaders allow you to work in very tight areas – places where tractors can’t even begin to access. Articulated steering is similar to having two very short machines attached together with a rod, so really you are operating a very short machine and the other chassis follows behind. Tractors on the other hand have a rigid chassis and are no-where near as maneuverable as a modern articulated front end loader. This ability to operate in confined areas of articulated front end loaders allows you to gain access to places you couldn’t with your tractor. The higher utilization rate of articulated front end loaders pays off with less jobs having to be performed manually. Often maintenance that has been done for years by hand, now gets done rapidly with a compact articulated front end loader! The much better all around visibility in a compact articulated front end loader also makes productivity in confined areas much higher as the operator isn’t concerned about damage to buildings, machinery, personnel or animals constantly on the job site.

2. Steering under load. Articulated front end loaders utilize strong rams to pivot the whole front chassis which steers the vehicle in the required direction. The powerful steering is required as under load the centre of gravity shifts approximately 2/3 of the whole machine onto the front axle, making it heavy under load if the steering isn’t suitable. Tractors however are designed to tow – this is the reason the big wheels designed for heavy loads, are mounted at the back and the small wheels, which are easier to steer, are mounted at the front. When a front end loader is added to a tractor and the operator loads the bucket, the tractor’s centre of gravity shifts onto the front wheels and axles, making it very hard to steer as they aren’t designed to turn under such a heavy load. As the centre of gravity shifts when a load is picked up with the front end loader a massive amount of pressure transfers onto the front axle and CV joints in the tractor. Tractors really are designed to tow and when loaded on the back of the three point linkage when towing, pressure is actually reduced on the front wheels as the centre of gravity shifts backwards taking pressure off the CV joints! Tractor front axles aren’t designed for the constant loading when working with a front end loader and may not last. Front wheel assist has now been included by some tractor manufactures to help with the steering when the front end loader takes a full load but it still has difficultly under full load as the CV joints are loaded up and under stress. Articulated front end loaders however have rigid axles so they don’t have any CV joints to get damaged under when the centre of gravity shifts forwards when loading – the steering is controlled via articulating the whole front chassis – just another reason showing that articulated front end loaders are truly designed from the ground up for loading, particularly in the long run when maintenance costs are taken into account.

3. Loading speed. Many farmers load their trucks with tractors, however when you load with a big tractor you waste a lot of diesel compared to an articulated front end loader. When operating a big tractor you need a lot more space to get in the right position to load and then to dump into the truck. The truck must be parked much further away from the pile of material to be moved as the tractor has limited maneuverability.

On the other hand articulated front end loaders operate easily in very confined areas so they don’t need to travel as far to dump and get in the right position to load again. This is due to the very tight steering angle – one of the greatest advantages of an articulated vehicle. The most efficient compact articulated front end loaders on the market now have articulation angles of 47 degrees. Smaller articulated front end loaders, generally under 1750kg, have articulation angles of 60 degrees as they don’t incorporate a drive shaft so the articulation angle can be made much higher.

4. Transmission advantages. Most modern articulated front end loaders utilize a clutchless hydrostatic transmission which gives you smooth power transfer when digging constantly into soil or hard materials. The hydrostatic transmission makes articulated front end loaders much faster in speed than tractors in loading situations, allowing the operator to perform more work in less time. As articulated front end loaders use a fluid hydrostatic the operator isn’t wearing out mechanical clutches or gearboxes with friction as you would need to constantly shift between gears with a manual gearbox like in a tractor.

The hydrostatic transmission that is used in the most modern articulated front end loaders allows the driver to concentrate solely on loading the bucket rather than having to change manual gears all the time to maximize speed against the torque required for loading. The hydrostatic transmission means that the articulated front end loader can be driven into a pile for loading and the hydrostatic pump is load sensing and automatically senses the power required and adjusts torque as necessary for the most efficient loading. The speed in the hydrostatic articulated front end loader is controlled just by pressing the accelerator pedal down more or less, the same as operating an automatic car.

5. Low operating height. Some modern compact articulated front end loaders are built with very low operating heights. This allows you to go inside buildings and perform more work. Tractors are designed for towing with large rear wheels and so are much higher and could never access such low areas. This allows many intensive farming operations such as small horse stables, cow sheds, chicken pens and greenhouses to be quickly cleaned out. Compact articulated front end loaders are also generally much narrower than equivalent tractors and allow access up the side of residential properties, building sites, and vineyards. A big advantage of compact articulated loaders is that the low height and narrow width allow access into building and demolition sites for construction and removal of debris.

The low height and relatively narrow width of articulated front end loaders when further coupled with the extremely tight turning circle gives even more accessibility in confined spaces. The low operating height of a compact articulated front end loader also gives another benefit not realized at the beginning – the easy access for personnel to the cabin area means they get used constantly for all jobs as they are so convenient. Tractors, due to their high wheels at the back must have high cabin heights and constantly getting in and out can be chore, particularly for smaller tasks and where one has to get in and out of the cabin frequently and so often the job is just done by hand. Another advantage of the low height of compact articulated front end loaders is when trucking machines about the total transport height is lower and permits don’t need to be obtained.

6. Centre of gravity. Articulated front end loaders are built from the ground up to maximize the efficiency of the weight they can lift at the front of the machine. The placement of counterweights and the longitudinal centre of gravity on an articulated front end loader is designed completely differently to that a tractor. Articulated front end loaders have a very heavy chassis and the most efficient designs incorporate weight as far behind the rear axle as possible to make lifting at the front as efficient. Significant weight as far out the back of the rear axle as practical makes it possible to lift higher amounts at the front of the articulated front end loader due to the simple lever principle – the more counter weight out the back, the more effective it will be. Articulated front end loaders when unloaded have approximately 2/3 of the total machine weight resting on the rear axle, however when loaded the centre of gravity shifts to 2/3 of the total weight on the front axle.

Tractors on the other hand are built completely differently to an articulated front end loader – all their weight is mounted as far forward as possible to give the best stability and capacity when towing – counterweights are even designed to hang off the front of the tractor! Their longitudinal centre of gravity of a tractor is approximately 50/50 on the front and rear axles, with a shift towards more weight on the front axle in bigger tractors. A quick look at any tractor shows that the engine has been mounted as far forward as practical which gives great stability at the back of the machine and allows the tractor to maintain weight on the front wheels for traction when towing a heavy object – the opposite of an articulated front end loader.

7. View of front end when operating. Compact articulated front end loaders are built from scratch to have a great view of the front end as this is where all the work occurs and the driver must have a great view if they are to perform work quickly and safely. The front chassis on an articulated front end loader is minimized in size so maximum visibility is created for the driver. The mast is also designed to be as streamlined as possible so no interference occurs to the drivers view and anything unnecessary is put behind or underneath the driver such as the engine.

The view of the front end of a tractor is totally different – tractors are designed for towing so the engine is put as far forward as possible and then a front end loader mast added afterwards. The tractors engine totally obscures the front end of the tractor so it is very difficult to see the working face and more guess work and less precise work has to be performed with a tractor than an articulated loader. The tractor is thus can only be used for very rough work and all finishing must be performed by another machine or done later by hand. It is very easy to see which machine is built for heavy duty work – an articulated front end loader or a tractor with a loader, pay careful attention to the size of rams, pins and the strength of the mast and it is quickly apparent that only a good quality articulated front end loader is built for an industrial life.

8. Towing Vs pushing. Articulated front end loaders are built for constant pushing. However, tractors are designed for towing; they are not designed to develop the pushing force which is needed for loading and shifting. Generally everyone understands that the bigger the wheel, the less the torque that can efficiently generated from it. The massive rear wheels of big towing tractors make the ability of developing a lot of torque an impossibility, however big tyres at the back create a lot of stability and the ability to have massive loads on the rear utilizing the three point linkage perfectly. The front wheels on tractors however are very small and not designed for the same loading as the rear – hence their small size. Articulated front end loaders however have the same tyre size all around which are much smaller than tractors so it is easy for the axles to generate much higher torque which is required to dig into hard materials when loading or cutting into bare earth.

Like a Swiss Army Knife on wheels, a skid steer loader can support a huge range of additional attachments to enable it to be used for an unbelievable variety of jobs. Your standard issue skid steer loader comes with a bucket attachment, but its capabilities don’t end with just humping mud and dirt about. Here are just some of the attachments available for your skid steer loader, and a brief explanation of what they do.

Augers – These look like giant drill bits. They use the Archimedes principal to dig deep, clean holes for foundations.
Claws – hydraulic grapples that are used to grab and lift heavy objects.
Hitches – like the trailer hitch on your car. Attached to the back of the loader and used to pull trailers and so on.
Backhoes – a steel bucket attached to a rotatable hydraulic arm used for digging and scooping.
Mowers – for cutting the grass!

Dozer Blades – a large metal blade fitted to the front of the skid steer loader. Used for pushing dirt and debris..

Plows – like a blade but can have a curved plate at the top, or be angled in a v shape to enable snow or leaves to be pushed to the side
Rakes – for scarifying ground and gathering loose material like leaves.
Forks – same as you would find on a forklift, these blades are used to carry palletized materials and suspended loads such as heavy bags.
Trenchers – used for digging ditches or long trenches.

The list above is only a small selection of the hundreds of additional tools that you can buy for your skid steer loader. You will probably never need most of them in you day to day work, so it’s good to know that there are many hire shops around the country that will rent you specialist tools on a daily or even an hourly basis. Thanks to the skid steer “quick attach” system most of these attachments can be used on any brand of skid steer loader, although there are some exceptions so its worth checking suitability with your supplier before purchasing.

The skid loader is a rigid frame, engine powered machine with lift arms that are used to attach a wide variety of labor saving tools or attachments. Skid loaders are normally four wheel drive with left side drive wheels that are independent of right side drive wheels.  With each side being independent to the other, the wheel speed and direction of rotation of the wheels will determine which direction the loader turns.
Skid loaders are capable of turning in their own tracks, which makes them very maneuverable and valuable for jobs that require the use of compact, agile loader.
Unlike conventional front loaders, the lift arms lay beside the driver with the major pivot points located behind the shoulders of the operator.  Due to the operator being in close proximity to moving booms and buckets, earlier models of skid loaders weren’t as safe as conventional front loaders, particularly during entering and exiting.

Skid loaders today have fully enclosed cabs and other safety features that will protect the operator from injury.  Just like other front loaders, the skid steer can scrape material from one location to another, carry material in a bucket, or load material on a truck or a trailer.

Operation
A skid loader can sometimes take the place of a large excavator by digging a hole out from the inside.  The skid loader will first dig a ramp that leads to the edge of the hole.  Then, the loader will use the ramp to carry material out of the hole. 
The skid loader will then reshape the ramp by making it steeper and longer as the excavation gets deeper.  This method is very useful for digging under an overhead structure where the overhead clearance doesn’t allow for the boom of a large excavator, such as those situations where you are digging a basement under a house.
The bucket of most types of skid loaders can be replaced with several specialized buckets or attachments, many of which are powered by the hydraulic system of the loader. 

History
The first 3 wheeled front end loader was invented by two brothers, Cyril and Louis Keller in their machinist shop in Minnesota back in 1957.  The Kellers built the loader to help a nearby farmer clean turkey manure from his two story barn.  The light and compact loader, with the rear caster wheel, was able to turn around within the length of itself, while performing the very same tasks as conventional front end loaders.
Down the road, the Melroe manufacturing company in Gwinner, North Dakota, purchased the rights to the Keller loader in 1958 and hired the brothers to continue their loader invention.  Resulting from the partnership, the M-200 self propelled loader was introduced at the end of 1958.

The loader featured two independent front drive wheels and a rear caster wheel, a 12.9 engine and a 750 lb lift capacity.  Two years later, they ended up replacing the caster wheel with a rear axle and introduced the M-400 loader, which was the first four wheel skid steer loader in the world.

In 1962, the Bobcat name was added to describe the key features of the machine – touch, agile, and quick.  The M-440 was powered by a 15.5 HP engine and offered a 1100 lb rated operating capacity.  In the mid 1960s, the skid steer loader progressed with the introduction of the M600 loader.

Years later, the Bobcat skid steer loader experienced quite a few changes, including the development of a hydrostatic drive system, enforced cab structures, radius and vertical lift arm configurations, deluxe instrumentation, and even heating and air conditioning.
In addition to the rubber tire skid loaders of today, there are now all-wheel steer loaders and even compact track loaders. Compact track loads offer less ground disturbance and feature better traction and control in soft, muddy, wet, and even sandy ground conditions.

For additional information about skid steer loaders visit Save on Construction Heavy Equipment at The writer operates a website selling used construction equipment and providing information at http://www.saveonheavyequipment.com

There are just so many different types of machines and equipment out there being used for construction, commercial and agricultural purposes and the skid steer loader, also commonly referred to as the skid loader is but one of them. It’s a mobile machine on wheels or tracts. It has a rigid frame, lift arms, and is fitted to accommodate a wide variety of tools and accessories that attach onto it.

The number and variety as well as the usage of attachments that have been developed for the skid steer loader over the years is simply amazing and virtually all of them are powered by the loaders own hydraulic system. Post hole diggers, scoops, concrete breakers, stump grinders, ditch diggers and rock breakers are typical examples of some of the most commonly used tools of this type.

One very recognizable common trait of Skid Steer Loaders is their size. They are a smaller machine that’s designed for medium to light jobs in confined working conditions. In fact, one of the newer types of skid loaders to appear on the market is new mini skid loaders that don’t even have seats. The operator stands on the back to operate the machine that often times is no larger than a common lawn tractor.

One very unique feature of these machines is their wheel or track operation. The four wheel versions that aren’t fitted with tracks are usually four wheel drive. That’s not unusual but what is unusual is that the wheel or track systems on each side of the machine are designed to operate independently of one another. The result is that these machines can turn on a dime while standing perfectly still. The zero radius turn.

The first prototypes for what has become the modern day skid steer loader became operational in 1957. Oddly enough, these were three wheeled vehicles that had two wheels in the font with one in the back. This arrangement allowed them to do the zero radius turns by simply positioning the steering mechanism in the single back wheel.

Subsequently, in 1958 Melroe Manufacturing acquired the rights to the machine and some three years later, the first four wheeled models were being manufactured by them. Of course, since then it has been licensed out to other manufacturing firms and also has undergone many more improvements, including tracks that replace wheels in some models as well as so many of the tools and machines that are able to be added on.

The main benefits that make the skid steer loader the machine of choice in such a wide variety of applications are its low cost and versatility. It basically replaces a two to four man crew in so many of the tasks that it performs. Also due to its smaller size and simplicity of operation it’s far safer machine to have and use on a job site. Also some of its tools are in turn adaptable themselves.

However; it is the newer “mini” skip steer loaders that are powered by powerful smaller economical motors that are really catching on. Contractors are finding that with the money it takes to pay a man’s wages for six months, they can buy one of these machines that effectively do the work of two men. They never need to take breaks or call in sick either.