Forklifts

A forklift truck, a lift truck, or a forklift is a powerful industrial truck which is used to lift and carry materials, usually by means of steel forks inserted under the load. Generally the loads are stored on pallets. The story of fork lifts started in 1920s and has since then become something without which the modern age cannot move in the world of manufacturing and warehousing. There are many associations related to the industrial trucks. These have come together to form joint statistical and engineering programs. Every month a publication is brought out whose information has in depth information and not confined to mere statistics of any one region of county. The outcome has been a form of standardization known as the Class System to which most of the important major manufacturers adhere to.

Broadly speaking some general types of fork lift trucks may be mentioned. These are hand pallet trucks, walkie low lift trucks, rider low lift trucks, towing tractor, walkie stacker, rider stacker, reach truck, electric counterbalance truck, IC counterbalanced truck, telescopic handler, ship sheet machine, walkie order picking trucks, rider order picking truck, and very narrow aisle truck. There are many other types of forklifts. Narrow aisle forklifts can operate in a space which is as narrow as six inches. Rough terrain forklifts operate outdoors over uneven ground.

Basically there are two main ways forklifts are powered. Electric forklifts are the best choice for indoor use and low operating costs. These are clean and quiet making them ideal for warehouses and manufacturing appliances. These do not produce emissions. This is a very important point in today’s world. Of the internal combustion models only propane fueled lifts can be used indoors. However, good ventilation is a must. Gas and diesel fueled models cannot be used indoors under any circumstance. Fuel cost is the main positive point. Electric forklifts come first in rank on this issue. Of course initial costs are high but in the long run the cost at the outset is made up through fuel savings. New electric forklifts may cost 20% to 40% more than similarly rated IC forklifts, but the fuel saving factor cannot be ignored. The next gaining point is that in electric forklift operation is much quieter and does not require fuel storage facilities. The life span of these tends to be longer because of the clean environment in which they work, requiring less maintenance.

On the negative side electric forklifts is dependent on battery time. These forklifts are powered by large, heavy, lead-acid batteries. It is a larger version of the type of battery that you use in your car. On average the batteries provide power for one eight hour shift, which in terms of actual usage means five to six hours of work. It takes eight hours to charge a battery together with another eight hours for cooling it. Thus additional batteries have to be kept ready. This increases costs.

Not to be overlooked is the need for a nearby battery charging station. The chargers should be kept in a location which is dry, ventilated, and temperature controlled. Special cranes will be required to handle multiple batteries. Moreover electric forklifts are not suited for outdoor use. You may stretch its use on a well paved parking lot but on the condition that the forklift is never exposed to rain. For outdoor use and easy refueling the answer is IC (Internal Combustion) forks.

A typical lift truck consists first of the truck proper which is a machine on wheels or tracks powered through a drive train. Second, there is an internal combustion engine fueled by LPG, petrol or diesel or an electric (AC or DC) powered by either battery or fuel cells. Third there is the mast. This does the job of lowering or raising or tilting the load. The mast is operated either hydraulically or with a chain. In the first instance there are one or more cylinders and interlocking rails. In the second system a hydraulic motor empowers the machine. Fourth there is the carriage. This consists of a flat metal plate or plates and is moved along the masts with the help of chains. There are one or more forks that grapple with the load.

The rear vertical portion of the forks attaches to the object with the help of a hook or latch. Some forks use a shaft mount. The front horizontal portion is usually tapered for easy insertion. This is slid into or under the load generally on a pallet or skid. A variety of other instruments may also be used to suit specific needs. The names of some of these are slip sheet clamps, carton clamps, carpet rams, pole and container handlers, roll clamps, etc. Another feature is a load backrest. It is fixed when the load is higher than the top of the carriage. It consists of an extension, which is like a rack, and is either bolted or welded to the carriage to stop the load from shifting backwards.

Rider operated machines have an over head guard for the driver. This is a roof made of metal supported by posts to protect the operator. The cab consists of a seat for the driver and includes control pedals, steering wheel, levers, and switches. There is also a dashboard with read outs for the operator. The cab may be open or closed but in either case it is bound by a cage like overhead guard assembly. In another model of counter balance machines there are counter weights. These are heavy iron masses fixed to the back of the machine. It is required to counter or make up for the load. In another type of forklift the large lead-acid battery serves the purpose of the counterweight.

Forklift trucks come in many varieties with different load capacities. Typically most forklifts have load capacities around one to five tons, though there are instances of forklifts having 50 tons capacity. A control raises and lowers the forks. These forks are also referred to as blades or tines. The driver tilts the mast to make up for the tendency of the load to angle the blades towards the ground and thus risk the possibility of it slipping off the forks. The tilt also provides some sort of ability to move the contraption on ground that is not level. Some models provides for the operator to move the tines and backrest laterally. This allows for easier placement of load. Other forklifts are fitted with a mechanism that allows the tines to be rotated. This is an aid for handling of skids that may have become excessively tilted and are used for other special handling work. Few other machines come with a hydraulic mechanism that allows rotation of the tines.

In addition there are other models that have a hydraulic mechanism that allows for the tines to move together or apart. This does away with the necessity of the operator to dismount and manually adjust for different sized loads. There are roll and barrel clamp attachments for handling barrels, kegs, or paper rolls. There are clamp pads that grab the load. Such fixtures usually have a rotation function so that a roll of paper which has been stored vertically can be inserted into the horizontal intake of a printing press. In some places, such as warehouses where carpets are stocked, a long metal pole is used instead of forks to life large rolls. The same type of lift truck, although much bigger, can be used for picking up heavy metal coils. In another variation forklift trucks, instead of forks there are clamp fixtures that can open and close around a load. In this way cartons, boxes, and the like can be shifted. The item is squeezed, lifted, and then carried off. These are sometimes referred to as clamp trucks.

The standards of safety for fork lifts vary from region to region. The most important set of standards is the ANSI B56. The leadership however has been now passed from ANSI to the Industrial Truck Standards Development Foundation after many years of discussion. ITSDF is a non-profit organization. Its only objective is the executing and updating of the B56 standard. For more details you can surf the net.

Forklifts are rated according to their load capacity and its specific forward centre of gravity. This information is given on a plate by the manufacturer. The loads are never to exceed these specifications. In many regions it is illegal to remove or tamper with the name plate without the written permission of the manufacturer. A forklift must never be used as an elevator for personnel without being specifically fitted with the necessary equipment such as ‘cherry picker’ or ‘cage’. There are annual Forklift Rodeos for skilled forklift operators who get a chance to show off their mastery in this field, observing all the safety rules.

Many forklifts have rear wheel steering. This increases their ability to maneuver in tight situations. This is different from the traditional experience of a driver. In order to turn a forklift the driver must consistently apply force. A second important aspect of the forklift is its instability. The forklift and the load must be viewed as a unit – a unit whose center of gravity is continuously changing with every motion of the load. Therefore a forklift with a load must never make a speedy turn. Centrifugal and gravitational forces may combine to cause a dangerous accident. The forks of the forklift have specific load limits. These are decreased with the elevation of the fork and undercutting of the load. A loading plate is generally placed on the forklift.

The work of forklifts is to engage, lift, and transfer load. These can be divided into eight numbers and categorized according to the type of drive. The forklift family also includes fork trucks. There are three basic types – manual drive, motorized drive, and fork truck. With the manual drive forklifts the load movement is manually powered. Motorized forklifts have a motorized drive with a cab or seat for the operator. This seat is caged or protected. Fork trucks are also motorized but include cabs and back up alarms. Some models are counterbalanced to avoid tipping. Others models have handrails, safety rails, or a rotating fixture known as a turntable. Truck mounted forklifts are mounted or are capable of being mounted on a utility truck. Important points to note are lift capacity and stroke. Lift capacity is the maximum supportable force or load. Stroke is the difference between the fully powered and fully raised lift positions. Other things to be noted before purchasing are fuel type and tire type. The fuel may be electricity, LP, natural gas, compressed natural gas, propane, gasoline, or diesel. Tire types are mainly two for forklifts and fork trucks – pneumatic and solid.

The forklift family consists of eight classes. There are forklifts which are three wheeled electric motor rider trucks – where the driver has to operate in a standing position. Class two consists of the electrically driven model which can operate in narrow spaces with extra reach and swing function. In the third class are electric forklifts which are either walk-behind or standing rider operated. Automated pallet lift-trucks and high lift models are fitted with counter balance contraptions. The fourth class consists of rider fork trucks with cabs and seated controls. The engines are of the internal combustion variety and have solid tires. The fifth and last class consists of forklifts that are rider fork trucks, with cables and seated controls, IC engines and pneumatic tyres. These are fitted with counterbalance mechanism like the fourth class. The sixth class has a sit-down rider and tow tractor lifts. It is supplied with both electric and IC engines. The seventh class is used for operating in rough terrain and ideally suited for farming, logging, and construction. The last and eighth class of forklifts is personnel burden carriers.