FORKLIFT BASICS
An Introduction to Forklifts
Introduction
The aim of this webpage is provide a resource to warehouse managers and their employees new to the materials handling industry. Below, you will find basic explanations of terms with pictures and links to products that support the warehousing and materials handling industry. The understanding of what a forklift is, what makes up a forklift, and some of the vernacular associated with forklift industry is crucial for good communication among materials handling professionals.
Click index heading to jump to topic
INDEX:
Data Plate
Brake Inching and Accelerator
Operator Controls
Hour Meter
Operator Restraint
Standup Operator Controls
Counter weight
Steer Axle
Industrial Batteries
Battery Connectors
Battery Chargers
LPG Tanks
LPG Tank Brackets
Warning Devices
Tires
Definitions
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BASIC FORKLIFT KNOWLEDGE
What is a forklift? A forklift is a powered piece of equipment designed to lift and transport material in an industrial setting. Other names for a forklift are: Tow-motor, lift truck, industrial truck, cherry picker and others. A forklift can be a very versatile and useful piece of equipment and the wide variety of attachments that can be added to a forklift make them even more useful. There are numerous types of forklifts and they will be discussed in this text. The intent of this is to give the reader a good working knowledge of the types of forklifts and the nomenclature associated with the components of a forklift.
TYPES OF FORKLIFTS
There are number of different types of forklifts. The model that any one customer would use depends on their application. Most forklifts are designed to work in a specific application but sometimes they can be use in other applications. The types and applications of some of the more common forklifts are as follows.
CLASSES OF FORKLIFTS
The Industrial Truck Association (ITA) has defined seven classes of forklifts. These classes are defined by the type of engine, work environment (indoors, outdoors, narrow aisle, smooth or rough surfaces), operator (sit down or standing), and equipment characteristics (type of tire, maximum grade). Several classes are further divided by operating characteristics. The following are the forklift classifications:
Class 1 forklifts are electric motor trucks with cushion or pneumatic (air filled) tires. Class 1 forklifts include four subcategories, or lift codes, which are:
• Lift code 1 - Counterbalanced rider type, stand up.
• Lift code 4 - Three wheel electric, sit down.
• Lift code 5 - Counterbalanced rider, cushion tire sit down.
• Lift code 5 - Counter balanced rider, sit-down rider (includes pneumatic tire models).
Class 2 forklifts are electric motor narrow aisle trucks with solid tires.
Class 3 forklifts include electric hand trucks or hand/rider trucks with solid tires.
Class 4 forklifts are Internal Combustion Engine sit down rider forklifts with cushion tires and generally suitable for indoor use on hard surfaces.
Class 5 forklifts are Internal Combustion Engine sit down rider forklifts with pneumatic tires. These are typically used outdoors, on rough surfaces, or significant inclines.
Class 6 forklifts can either be electric or Internal Combustion Engine powered. These are ride on units with the ability to tow at least at least 1000 pounds. This class is designed to tow cargo rather than lift it.
Class 7 forklift are rough terrain trucks with pneumatic tires. Class 7 trucks are almost exclusively powered by diesel engines and are used outdoors.
INTERNAL COMBUSTION (IC) CUSHION TIRE FORKLIFT: These trucks are typically used indoors in applications such as manufacturing, warehousing, bottling and trucking. They ride on solid rubber tires called cushion tires. They can be powered by either Liquid Petroleum Gas (LPG), gasoline, Diesel, or be dual fuel. Dual fuel means that the forklift is equipped with both LPG and Gas fuel systems and can be run on either one but not at the same time. The engine powers all the functions of the truck, drive and hydraulics. This is a Class 4 forklift.
Four Wheel Sit Down IC Rider Cushion Tire Forklift
INTERNAL COMBUSTION PNUEMATIC TIRE FORKLIFT: This type of forklift is used primarily in outdoor applications where the operating surface may be uneven. It utilizes larger tires which can either be air filled (pneumatic) or pneumatic shaped solid rubber tires. Like the Cushion tire truck it can be powered by LPG, Gasoline, Diesel Fuel or can be dual fuel. Although this type of truck is intended for outdoor use, it does not do well in soft materials such as sand or loose gravel. This is due to the fact that a forklift really has no suspension and it is not possible to maintain tire to ground contact in uneven environments. These are Class 5 forklifts
Four Wheel Sit Down Pneumatic Tire Forklift
TRUCK MOUNTED FORKLIFT: The truck mounted forklift is a very versatile forklift. It is mounted on the back of a truck and can be carried to the worksite and dismounted there to unload the product right at the site making it unnecessary for the customer to have a forklift at the construction site. One notable feature of this type of forklift is that the lift cylinder is normally a double acting cylinder. This means that the cylinder is pressurized when raising or lowering the forks. This enables the forklift to lift and lower itself using the hydraulics and the forks. It can be loaded or unloaded from a truck in a matter of minutes. This type of forklift is very popular with lumber yards, brick yards, and sod farms.
Truck Mounted Forklift
Truck mounted forklift, mounted on the truck.
ROUGH TERRAIN FORKLIFT: A rough terrain forklift is designed for carrying material over terrain that a normal pneumatic tired forklift will not. The most notable feature of the rough terrain forklift is the oversized, aggressive treaded tires. This enables the machine to traverse bumpy, soft or muddy terrain without getting stuck. Many models of rough terrain forklifts are also 4-wheel drive. A rough terrain forklift is a Class 7 forklift.
Rough Terrain Forklift
ELECTRIC SIT DOWN RIDER FORKLIFT: This type of forklift is designed primarily for indoor use. It is powered by a large industrial battery. All the functions (drive and hydraulics) are controlled electrically. It looks much like its IC powered counterpart. The drive system and hydraulic systems are driven by electric motors. They can come in 3 or 4 wheel configurations. While most electric sit down riders use cushion type tires, some are ordered with a solid pneumatic tire and wheel combination. The 4 wheel versions are Class 4 forklifts.
Four Wheel Sit Down Electric Rider
Three Wheel Electric Sit Down Rider (Class 1)
Stand Up Counter Balance Electric Rider (Class 1)
NARROW AISLE TRUCKS: A narrow aisle forklift is designed to operate in warehouses. It is a standup forklift meaning that the operator is standing up while operating the machine. Its primary function is pulling and placing products on racks inside a warehouse. It is normally not used to load trucks. A narrow aisle forklift can operate in aisles between racking that is spaced closer together than the rack spacing required for a sit down rider. Applications: Grocery, Distribution and warehousing.
Narrow Aisle Reach Truck
A narrow aisle reach truck uses a pantograph to extend the forks out from the upright. When extended, the forks are past the load wheels. There is also a double reach trucks which has an additional segment in the pantograph which allows the forklift to pick and place loads two deep on pallet racking.
ORDER SELECTOR: An order selector is also called an order picker or man up forklift truck. This is because the operator actually rides up on the platform so that his feet are at the same height as the forks at any given time. This machine is used in warehouses to “pick orders”. In other words, the operator will go up to the level that the product desired is stored and physically pull the items desired and place them on a pallet or platform that is sitting on the forks. Order pickers must always have a tether or lanyard attached on one end to the forklift and the other attached to a belt or harness on the operator. This is to prevent the operator from falling to the ground from the operating height should the operator fall off the working platform. Notice that this type of forklift has outriggers. Outriggers are the legs that are on the front of the forklift that have the smaller load wheels. Normally the load wheels are polyurethane as is the drive tire. Application: Distribution and warehousing. Order selectors are Class 3 forklifts.
Order Picker
Operator’s lanyard - Static lanyard shown above, retractable (seatbelt style) lanyard shown below
Very Narrow Aisle Truck
First introduced by RAYMOND in North America. The guided Swing Reach Turret style truck stores pallets in a "very narrow aisle" of as little as 66 inches. This is dual purpose forklift for man up pallet retrieval as well as orderpicking (case picking). These are considered Class 2 forklifts.
PALLET JACKS: Electric pallet trucks come in several varieties. There are stackers, rider pallet jacks and walkie pallet jacks. Walkie jacks are electric and the operator walks behind the machine steering it through the handle. Walkies do not have as high a travel speed as a rider pallet jack. Rider pallet jacks have the option of the operator riding (standing) on the unit and traveling with it. Both walkie and rider jacks lift from ground level to approximately 9 inches. Walkie stackers have an upright and lift to greater heights than pallet jacks. Once again, the operator walks behind the unit and steers it via the handle. Power workers are considered Class 1 equipment.
Application: Warehousing, distribution and manufacturing with relatively short runs (rider) or short runs (walkie).
Walkie Pallet Jack
Rider Pallet Jack
Walkie Stacker
ELF Rider Pallet Jack - used on the dock and in tight, congested areas
MANUAL PALLET JACK: The most basic piece of material handling equipment is the manual pallet jack. It is used to pick up pallets of material and move it from one location to another. Manual pallet jacks, by definition, do not have powered drive or lift. Standard dimensions of the forks are 48” long and 27” wide but they can be ordered with custom specifications. This type of hydraulic manual hand pallet jack, was invented by the Raymond Corporation in 1934. For the history of Raymond, click here.
Manual Pallet Jack - Over 75 years ago, Raymond invented the industry's first hydraulic hand truck.
Tugs
While not a forklift, this piece of equipment plays a role in the material handling industry. It is used to tow small trailers in and around warehouses and manufacturing facilities. Most are typically electric powered. Tugs are considered Class 6 equipment.
DEFINITION AND EXAMPLES OF FORKLIFT COMPONENTS
In this section, we will describe the parts that make up a forklift, show where they are in relation to the rest of the components and describe there purpose and limitations. For ease of discussion, the front of the forklift is in the direction the operator faces while operating it. The right hand side is the operator’s right side while on the forklift.
IMPORTANT NOTE ON CAPACATIES OF FORKLIFTS
All forklifts have a rating for their capacity. We will use a 5000 pound capacity forklift as an example. Generally, a forklift with a 5000 pound rating has its capacity based on a basic truck. A basic truck has a standard upright and no attachment. If the upright is changed to a triple stage upright and/or an attachment is added, the capacity of the upright is changed and these changes must be reflected on the data plate. The manufacturer of the forklift will provide you with the new capacity once a capacity change request is sent in with all the needed information.
Forks are the parts that actually go under the load, supporting the load as it is lifted. Forks are mounted on the front of forklift. They are usually used in pairs. There are several types of forks and they are mounted in a couple different ways. The two most common mounting types are hook type and pin type. Forks are usually described by their type and dimensions i.e. 42”X5”X4 ¾” pallet fork. The most common fork is 42 inches long.
The most common type of fork is the pallet fork. They are relatively thick with respect to their width and come in varying lengths.
Pallet fork
Hook mounted forks hang on the top of the carriage and are also secured from coming off the carriage by the lower hooks. They are also secured from moving by the use of a fork pin, which drops into notches cut out on the top carriage bar. Forks do wear out. Usually this is caused by the heel of the fork dragging on the floor. Once 10% of the material is worn off the fork, it should be taken out of service. This can be caused by the operator driving with the forks on the ground, the lift chains being out of adjustment, the drive tires being worn down or a combination of all of the above. If the lift chains are adjusted properly, the forks will be approximately ¼ inch off the ground when the mast is vertical. There is a tool available to check the wear. If more than 10% of the material is worn off the bottom of the forks, the forks should be taken out of service. This tool is a go/no go gauge. Either the forks are good or they are bad.
Fork Gauge used to measure wear on the heal of the fork.
Other more common types of forks are:
Brick Forks-which are not as wide as pallet forks and fit into pockets in blocks of bricks. They are usually used in sets of four. Brick forks can be either hook mounted or pin mounted.
Brick Fork
Lumber forks-are wider and thinner than pallet forks which allow the forks to be inserted between boards or sheet rock while maintaining the capacity required to lift the load. The forks are usually polished to allow sliding them in between the product with out damage to the product.
Lumber Fork
Bar Carriage Forks: or sometimes called pin mounted forks do not have top and bottom hooks. They are mounted via a large diameter pin that supports the load at the top of the fork. The pin is normally supported on each end of the carriage as well as in the middle. The bottom of the fork rests on the lower carriage bar.
Pin Mounted Fork
Fork Extensions: A Fork extension is device that is slipped over the fork to extend its length for handling oversize loads. Before using fork extensions, one must insure that the extensions are rated for a load and that the forklift can handle the weight at the new load center. A forklift equipped with fork extension should have the load rating of the forklift documented on the data plate.
Fork Extension
THE CARRIAGE
The carriage is the part of the forklift that the forks or other attachments are secured to. It consists of an upper and lower fork bar, two vertical parts to hold the carriage rollers . Carriages can wear out also. There is a gauge available to measure the wear on the fork bars. Wear is caused by constant loading and hammering of the mounting surface by the forks particularly the top fork bar. The carriage has notches on the top bar to facilitate the fork locks and they will normally have a large notch cut out of the bottom fork bar to allow the installation of the forks with the Load Back Rest (LBR) installed.
Carriages vary in size and classification. Forklifts up to 6000# normally have a Class II carriage and it would measure approx 16 inches from hook to hook. A Class III carriage measures approx 20 inches from hook to hook. A Class IV carriage would have a measurement of approximately 24 inches from hook to hook. A Class V carriage is approximately 28 inches from hook to hook.
Note: The class of the carriage is not the same as the class of the forklift. In other words, a Class 4 fork lift would not have a Class IV carriage.
LOAD BACK REST
The load back rest (LBR) does just what the name implies, when the upright (mast) is tilted back, the load being carried is resting against it. They are normally 48 inches high on a forklift and the same width as the carriage. On a reach fork truck, the standard is 36". On a pallet jack, they range in size from 48" to 60" and greater. A forklift should always have the LBR installed. A LBR should never be used as an anchor point for chains or ropes to pull objects. On a deep reach truck, extra caution must be used. The vertical rack opening must be larger that the load back rest with clearance because the carriage and the LBR enter into the rack bay.
LBR installed on a fork truck.
ATTACHMENTS
Many forklifts have what is called an attachment installed on the carriage. The attachment allows the operator perform different functions with the forklift. Before an attachment is installed on a forklift, the capacity of the forklift with the attachment added on must be determined. This is done by getting the weight, vertical center of gravity (VCG), horizontal center of gravity (HCG), effective thickness (ET) and capacity and load center of the attachment from the manufacturer of the attachment. The attachment should also have a data tag attached to it. This information along with all of the information that the forklift manufacturer requires to determine the capacity of the forklift is sent to them and they will give you either the information to stamp a new data plate or in many cases, you must order a new data plate.
The most common attachment is a side-shifter (S/S). This attachment is a false carriage assembly that moves the forks laterally providing greater accuracy when positioning the forklift in relationship to the load. It incorporates a carriage of sorts which is tied to the forklift carriage via a hydraulic cylinder which performs the movement. Side shifters have slides on the top hook area and slides or rollers on the back of the lower bar which keep the side-shifter from wearing out the forklift carriage. They do wear out and need to be changed periodically. Like the forklift carriage, the top hook area wears out from the forks A loading on them and may eventually need to be replaced. They can be checked with the same tool used to check carriages.
Many RAYMOND forklifts come now with integral sideshift. The benefit being that by being integrated into the carriage, the headlength and therefore the overall length of the truck is reduced, increasing the maneuverability of the forklift.
Side-shifter Cylinder
A side shifting fork positioner performs the same function as a side shifter with the additional ability to move the forks closer or farther apart from each other to accommodate different loads. This attachment requires additional hosing to perform the secondary function. There also non side shifting fork positioners. Download a brochure here.
A Carton Clamp is an attachment that is used to pick up relatively light, square product such as TV’s, water heaters etc that are packaged in boxes nested together. The product is not on pallets. There are side-shifting carton clamps as well. Download brochure here.
A rotator is an attachment that is used to dump product that is in a container of some sort. This can range from produce like chile’s to scrap metal and the like. It is capable of rotating the forks 180 degrees. The forks must have fork lock pins installed to keep them from falling off while rotating.
A paper roll clamp is an attachment made for picking up rolls of paper. It will have 1 or 2 moveable arms which will clamp on to a roll of paper. The pressure in the system must be set properly to keep from dropping the rolls or smashing the rolls. Roll clamp guide can be downloaded here.
A slip sheet attachment (push pull) is an attachment that is used to pick up product that is shipped on a stiff paper sheet rather than a pallet. The attachment uses a pantograph assembly and gripper mechanism that grabs the paper which extends out from under the load and pulls it back on the platens. It is then transported to where ever it is going and the attachment pushes the load off the platens. This attachment eliminates the need for pallets although, with this attachment , pallets can still be picked up due to the space between the platens. Download information about push pull attachments here.
Other Types of attachments are as follows:
Bar Arm Clamp: This is an attachment that has two poles sticking out the front of the attachment, not unlike forks, that can be spread or closed to pick up products like rolls of cloth etc. Download a brochure here.
Carpet Pole: A carpet pole or textile boom is an attachment that is mounted onto the carriage and basically consists of a long pole that is inserted into a role of carpet to facilitate picking it up. They are not normally mounted permanently and do not have any hydraulic functions associated with them.
Basaloid (a.k.a. appliance handler attachment): This is an attachment that is mounted on the carriage or side-shifter that is used to pick up appliances. The cartons that appliances come in are constructed such that they have a cardboard lip on the upper end of the box that the basaloid slips under and allows lifting of the carton.
Pallet Handlers a.k.a single-double): A pallet handler is an attachment that can be expanded to go from handling one pallet to two pallets. This attachment is common in the beverage industry.
Drum Handler
A drum handler is an attachment that is mounted on the forks of the lift truck and is used to pick up 55 gallon drums. They are usually designed to handle either one or two drums.
Forklift Drum Handler
MAST (a.k.a UPRIGHT)
The most obvious part of a forklift is the upright or mast as some call it. The mast is a telescoping rail configuration that allows the forklift to raise product off the ground up to its designated height. There typically 3 4 kinds of masts: standard (2-rail), triple stage (3-rail), and quad (4-rail). The rails are typically “nested” meaning they are some what interlocked. Almost all newer uprights use rollers to facilitate a smooth telescoping action. Uprights also utilize lift chains to sequence out the rails.
Some of the terms used when speaking about uprights are as follows:
OHL: Overall Height Lowered- The measurement from the ground to the top of the upright when it is fully lowered.
MFH: Maximum Fork Height- The height that the forklift will lift as measured from the ground to the forks.
FL: Free Lift- How high the forks can be lifted off the ground before the upright rails start to move.
STANDARD UPRIGHT (MAST): The standard upright has only 2 rails. There are 2 types of standard uprights.
The first is the simplex. Generally, the inner rail begins to rise almost as soon as the forks leave the ground. This means it has no free lift. Free lift (F/L) is the distance from the ground that the forks can be raised before the rails begin to telescope. This is because this type of upright uses 2 lift cylinders, mounted on both sides of the upright. Older forklifts used on cylinder in the middle of the upright but this obstructed the operators view. Once the cylinders begin to extend, the inner rail goes up with them also raising the forks. The major disadvantage of this type of upright is that, product can not be double stacked in trailers.
Primary lift cylinders are on the sides.
Simplex Mast-note how the rails are much higher than the forks.
The second type of standard mast is the two-stage mast, Duplex or Hi-Lo. This upright also has two rails but will generally have a lift cylinder mounted in the middle (primary lift cylinder) that will raise the forks before the outer cylinder(s) (secondary lift cylinder) begin to raise the channels. With this type of upright, double stacking is permissible in trailers.
Primary lift cylinder, secondary cylinder
This is a forklift equipped with a Duplex Upright. Notable Features- two rails-primary and secondary lift cylinders -lower lifting height than a triple stage but it does have free lift.
Triple Stage Upright: One of the most popular uprights due to its higher lifting capability is the triple stage upright. It will have three rails, inner, intermediate, and outer. It will also have primary and secondary lift cylinders. Like the duplex upright, it has free lift.
This is a triple stage upright extended. Notable features-three rails- primary and secondary lift cylinders and high lift with free lift.
Triple Stage Upright Collapsed
Quad mast (upright)
The last type of upright mast is the quad mast upright. This upright incorporates four rails instead of the two on a standard upright and the three rails of a triple stage. This allows for even greater lifting heights but, as you can also see, the visibility is somewhat reduced.
Quad Upright- note 4 rails.
Lift Chains
All uprights use a combination of lift cylinders, upright rails, lift chains and sheaves (pulleys) to lift loads. The lift chains are a critical link in the lifting mechanism. Most forklifts use a type of chain called leaf chain. This is simply multiple links pinned together to form a chain. There are usually two sets of lift chains on an upright. The two chains that lift the carriage and go over the primary lift cylinder are the primary lift chains. The second set of chains is used to lift the intermediate and inner rails. These chains are called the secondary lift chains. Lift chains will wear out over time and need to be inspected periodically to insure that they have not worn excessively. This inspection involves a visual check for kinks in the chain, cracks in the plates and the use of a chain gauge to determine stretch or wear. A chain with more than 3% stretch or wear should be replaced.
Leaf type lift chain
Leaf type lift chains and sheave.
TILT CYLINDERS
The next part you would find on a forklift as you work your way back is the tilt cylinders. The upright is usually mounted on a pivot at the base of the upright. This allows the tilt cylinder to extend and retract which will tilt the upright forward and back. The purpose of this tilting is to allow the load to be stabilized in a leaned back position against the load back rest (LBR). The higher a forklift can lift, the less the upright will be able to tilt. A forklift with a standard upright generally has more tilt than a triple stage.
Tilt cylinder
HYDRAULIC CONTROL VALVE
The hydraulic control valve is the device that controls the hydraulic functions of the forklift. Typically there are 3 handles on the valve. The one closest to the operator is the lift valve, next comes the tilt valve and then the sideshift auxiliary valve which controls the sideshift attachment (if one is installed). If the forklift has an attachment that performs two different function, say side shift and clamp, there would be a second auxiliary handle to the right of the first.
Lift Tilt Sideshift Attachment (4th function)
Hydraulic functions as they relate to forklift have a standard associated with them with regards to the direction of movement of the levers and the function performed. They are as follows.
Function Push Lever Forward and this happens: Pull Lever Backwards and this happens:
Lift Downward movement of the forks. Upward movement of the forks.
Tilt Upright tilts forward. Upright tilts back.
Side shifter Side shifter moves left. Side shifter moves right.
Fork-Positioner Forks open. Forks close.
Clamp Clamp opens. Clamp closes.
Rotator Counter-clockwise. Clockwise.
Push-pull Push-pull-Pushes. Push-Pull-Pulls.
INTERNAL HOSE GROUP
An internal hose group is pairs of hoses that are routed through the upright, usually following the same path that the lift chains do, to supply oil to the attachment on the carriage. If there is room, a forklift attachment requiring two separate feeds of oil will have two sets of internal hosing within the confines of the upright. If there is not room or a second internal hose group adaptation is not available, a hose reel will be used.
HOSE REEL
A hose reel is a device used to transfer oil to an attachment from the hydraulic control valve. It is often used when there is no room for an internal hose group in the upright or if a hose group is not available for the upright. Hose reels are normally mounted near the top of the upright and the free end of the hose is secured to the carriage. It consists of 2 or 4 hoses wrapped around a spool which is spring loaded to wind up the hose as the carriage nears the hose reel and let hose out as the carriage passes the hose reel. Hose reels come in left hand and right hand configurations depending on which side of the upright the reel is mounted on.
DRIVERS OVERHEAD GUARD
The drivers overhead guard (DOG) is the device that surrounds the operator compartment. It is designed to protect to operator from small falling objects. They are also called FOPS (Falling Object Protection System) They are usually tested to sustain a rated impact from above but they are no designed for such use. Normally, lights and alarms are attached to them from the factory. It is not permissible to modify the overhead guard by drilling or welding. Accessories that are added to the overhead guard should use existing factory mounting points or be clamped on.
Drivers Overhead Guard
FORKLIFT DATA/CAPACITY TAG
Probably one of the most important things that you will find on a forklift is the data/capacity tag. This small plate gives the operator some very important information regarding the forklift that he/she is driving. The information found on this plate includes some/all of the following.
- Make, Model and Serial number of the forklift.
- Rated Capacity of the forklift and at what center of gravity that rating is.
- How high the forklift will raise that load.
- What attachment is mounted on the forklift.
- Weight of the forklift empty and with maximum battery weight.
- Voltage of the forklift.
- Fuel used in the engine.
- Weight requirements for the battery.
- Amp Hour requirement s for the battery.
- Degrees of tilt the forklift is allowed to have equipped as it was when the plate was mounted.
- Tire sizing and type .
Typical Data Plate
BRAKE, INCHING AND ACCELERATOR PEDALS
Most IC forklifts will have 3 pedals by which the operator controls to acceleration and stopping of a forklift. The accelerator pedal operates just like the one in you car. The farther down you push it the faster the forklift goes.
The pedal to the left of the accelerator is the brake pedal. Again, just like your car, the harder you push it the faster the forklift slows down. Unlike a car, forklifts only have brakes on one axle. That is the drive axle.
To the left of the brake pedal is the “inching pedal”. This pedal is in the position that you would expect to find a clutch pedal. The inching pedal has two purposes. The first is to work like a clutch in the respect that it allows you to disengage the engine from the transmission so that you accelerate the engine to increase hydraulic speed. If the pedal is pressed down even farther it will actuate the brakes.
Inching Pedal Brake Pedal Accelerator Pedal
OPERATOR CONTROLS
In front of the operator, as he/she is sitting in the seat, you will find the operator controls. The most obvious control is the steering wheel. It is much like the one you would find in your car. Turning it clockwise will make the forklift go into a right hand turn. Turning the steering wheel counterclockwise will make the forklift go into a left hand turn.
To the left of the steering wheel you will find the directional control lever. Most later model forklifts us an electric shift transmission. This means that the transmission is shifted via electric solenoids on transmission. Pushing the directional lever forward will shift the transmission into forward. Pulling the lever rearward should make the forklift go into reverse. All forklifts must have a neutral safety switch in the starting system which forces the operator to put the directional lever in neutral before the forklift will start.
The parking brake on most sit down rider forklifts is either operated by a lever actuated by hand or by a parking brake pedal on the left hand side of the inching pedal.
Parking Brake Handle Directional Control Horn Button
Typical Sit Down Rider Operator Controls
HOUR METER
Almost all forklifts are equipped with an hour meter. The exceptions would be some power workers. A forklift does not have an odometer like a car; instead the number of hours they are operated is logged on an hour meter. A functioning hour meter is critical as it is used keep track of PM intervals. It is also used to calculate overtime billing on rental and Full Maintenance trucks. Hour meters take different forms. Many trucks use a simple hour meter that monitors the time that the forklift is running or an operator is on the seat switch. Some electric trucks, in addition to tracking brake pedal time, also monitor drive motor usage and lift motor usage. This is done through the logics card of the forklift. If an hour meter is damaged or a logics card is replaced, the old hour meter reading should be recorded so that the total number of hours can be tracked by adding the old reading to the new reading. This is especially important on rental equipment. Some logic cards can have the hour meter changed to the reading of the old card via programming of the card.
OPERATOR RESTAINT SYSTEM
Almost every manufacturer of a forklift offers some type of operator restraint system on their sit down riders. This usually consists of some type of hip/shoulder restraint as well as seat belts. These items are intended to keep an operator in position in the event of a forklift tip over. In addition to the hip/ shoulder restraint, there must be some sort of device to keep the hood deck from opening and also restrain the battery from leaving its position. You can not modify an existing operator system nor can you retrofit a truck that did not originally have and operator restraint system. Installing an improper restraint system on a forklift could endanger the operator in the event of a tip over.
Hip or Shoulder Restraint Seat Belts
STAND UP FORKLIFT OPERATOR CONTROLS
A stand up forklift, such a narrow aisle reach truck, typically will have all the hydraulic and directional controls incorporated into one “joystick”. Pushing the joystick forward will make the forklift drive forward and vise versa. Lifting the joystick will make the hydraulic motor turn on and the upright will lift. Pushing down on the joystick will make the upright lower. There are usually several buttons on the joystick to control the tilt and side shift.
On standup electric forklifts, there are two types of steering. The first is forward steering. With forward steering when the tiller is rotated in a clockwise direction, the forklift will turn to the right. The second type is reverse steering. With reverse steering, when the tiller is rotated clockwise, the forklift will turn to left. In other words, reverse steering is opposite of what most operators would normally expect. A forklift can generally be changed from one type of steering to the other with either a reversal of steering hoses or by the addition or deletion of an idler gear in the steering gear/chain configuration.
Steering Tiller Directional and Hydraulic Joystick Brake Pedal(s)
Typical Stand up forklift controls.
WALKIE/RIDER OPERATOR CONTROLS
Typically, a walkie/rider has all of its controls on one handle. It can be operated with one hand while driving the machine. The directional control is normally twist grips that the operator rotates in the direction of travel desired. The raising and lowering of the forks are controlled by the buttons in the center of the handle. Likewise, the horn is controlled by another button. One important feature it has is the “belly button switch”. The purpose of this is to keep the operator from being pinned between the machine and a stationary object. If the handle should come in contact with a stationary object, like the operator, it will reverse the direction of travel of the machine.
Accelerator Twist Grips Raise Lower and Horn Buttons Belly Button Switch.
Typical Walkie/Rider Operator Controls
COUNTERWEIGHT
A forklifts ability to pick up weight is primarily based on the fact that it has a counterweight mounted on the rear of the machine. This principal is much like a teeter totter in the way that a larger person is able to keep a smaller person in the air based on the weight differential. The counterweight is generally a cast piece formed into the shape desired. The other parts of the forklift also add to the counterweight effect. These parts would be the engine (or battery in an electric forklift), steer axle, frame etc. The combination of these parts makes up the total ability of the forklift to safely lift loads.
Counterweight
STEER AXLE
The steer axle is the axle that is in the rear of the forklift and provides the steering ability for the forklift. It also provides the articulation so that all 4 tires will remain on the ground while negotiating uneven terrain. A steer axle consists of the main frame, king pins and bearings, tie rods and steer cylinder. Most newer trucks have the steer cylinder integral with the axle while on older machines it is separate.
Steer axle w/ integral steer cylinder, cylinder is mounted transversely in steer axle.
Steer axle with out integral steer cylinder. Cylinder attaches here. And the other end mounts to the frame of the forklift.
INDUSTRIAL BATTERIES
Electric trucks are powered by an industrial DC voltage battery. Typically the batteries are either 12, 24, 36 or 48 volts. They are made up of individual 2 volt cells that are connected by inter cell connectors. In a 12 volt battery there would be 6 cells, a 24 volt battery would have 12 cells a 36 volt battery would have 18 cells and a 48 volt battery has 24 cells.
The battery placed in a forklift must meet several requirements:
First, it must be of the correct voltage for the truck. This is self explanatory; a 36V truck must have a 36V battery.
Secondly, it must have the correct amp hour rating for the truck. This will help insure that the battery is capable of running a full shift before the need for recharging.
Third, it must have the same connector as the truck and charger.
Finally it must have a weight that falls in between the minimum and maximum weights for the truck. These numbers are normally stamped into the data plate of the forklift. A battery that is too light will not allow the forklift to lift a maximum rated load safely. A battery that is too heavy will put excessive wear on the chassis of the forklift.