The Basics - Forklift 101
In Its Simplest Form, a Forklift… • Drives / Travels • Lifts / Other Hydraulic Functions • Utilizes Basic Hydraulics to Accomplish Work
Basic Hydraulics • Liquids cannot be compressed • Liquids can assume any shape and be bi-directional in free flow movement • Pascal’s Law states that when a confined liquid is placed under pressure, that pressure is transmitted, without change in intensity equally in all directions
Basic Diagrams
Multiplied Forces Do More Work • Principles of basic hydraulics allow forklifts to lift heavy loads
Pressure / Flow Must Be Created • Hydraulic pump – Usually gear type are utilized to create flow
Basic Hydraulic Diagram • Various Components Work Together to Accomplish the Work
Forklift Hydraulic Components • • • •
Hydraulic Reservoir (Tank) Gear Pump ( Creates Flow / Pressure) Control Valves (To Direst Flow) Control Valve Levers (Direct Manual) – Electronically Controlled (Joystick, Fingertip controls)
• •
Connectors – Steel tubing / hosing / fittings Cylinders (To Do the Work!!) Single Acting / Double Acting – – – –
Lift cylinders Tilt cylinders Steer cylinders Sideshift cylinders
Various Power Sources Engine Powered Forklifts
Fuel
Advantages
Disadvantages
Gasoline
Readily available, good power & performance, can run continuously, small & medium forklifts, high power to weight ratio, starts well in cold
Emissions, should not be used indoors, volatile costs, storage and refueling regulations
LPG
Readily available, easy refueling & tank storage, small & medium forklifts, cleaner burning, good power & performance, can be used indoors, can run continuously, usually costs less than gas
Tank change-outs might be difficult for some, volatile costs
Diesel
More durable engine designs, medium, large and extra large forklifts, sometimes better performance & power than gas and LPG, can run continuously
More pollutants, cannot be used indoors, volatile costs, storage and refueling regulations, might not start well in cold environment
Dual Fuel
An engine that runs on either gas or LPG, better flexibility and good for rental fleet trucks, can run continuously
Possibly more maintenance, volatile costs, possible refueling issues
Various Power Sources Battery Powered Forklifts
Fuel
Advantages
Disadvantages
Lead Acid Battery
Readily available, various sizes and capacities, utilized as part of the counterweight, zero emissions & no noise, lower maintenance costs
Purchasing fuel upfront, higher initial cost, replacement usually necessary, disposal complications
Fuel Cell
Old technology just making its way to forklifts, water is by-product of process, quick refueling for long running times, zero emissions
Durability concerns, very high acquisition costs & refueling station costs, not yet mainstream, not as efficient as “hybrid” noted below
Hybrid
Emerging technology, Komatsu the world’s first electric hybrid utilizing battery & capacitor for power, extended run times, zero emissions & noise, no hefty investments needed
Higher costs than normal lead acid battery, must recharge overnight at least weekly, battery replacement necessary after 4 yrs., paying for fuel upfront, possible disposal complications
Forklift Terminology • • • • • • • •
Mast Upright MFH OAHL FL LBR OHG QD
• • • • • • • •
Acronyms Etc. IHR • OSHA MPH • CARB FPM • EPA PSI • FPM Ah • TOPS HP • kW ITA • kN ANSI • dB
• • • • • •
Nm WB RPM U.L. NFPA Towmotor
Lift Truck Main Components •
Chassis
• Counterweight • Mast
Counterbalanced Forklifts • 99.9% are front wheel drive and rear wheel steering • Why? – In a loaded condition all of the weight is over the drive axle for maximum traction and braking power!!
• In a turning situation, the rear end of the truck swings while the front end stays stationary
Engine Powered Forklift Hydraulic pump
Battery Powered Forklift
PS motor
Mast Specifications •
OALH – Overall Lowered Height – The distance measured from the floor to the top of the mast when it is fully lowered and vertical – Critical for entering low clearance areas & doorways
•
MFH – Maximum Fork Height – Distance measured from the floor to the top of the forks in the full raised position – Critical to achieve the desired height to put-away a load
•
FL – Free Lift – Distance the forks can be raised without the overall lowered height of the mast increasing – Critical when working inside of a trailer or other low clearance areas
•
Ratio of OALH to MFH – Usually the same, but may vary based upon mast overlap / retention
Mast Types
OAHL - overall height lowered FL - free lift MFH - maximum fork height
OAHL FL
Mast Types 2 Stage Free View Mast • Large open visibility window • 2 Main Cylinder design – typically mounted behind rails. • Limited free-lift. 0 ~ 6”
Mast Types 2 Stage Full Free View • • • •
3 cylinder design 2 Main rear cylinders 1 Center cylinder is for freelift Full free-lift capability
Mast Types 3-Stage Full Free View • New UltraVizion Mast System (BX50) • 3 cylinder design • 2 main cylinders • 1 center cylinder for free-lift • Full free-lift capability 4-Stage Full Free View Available on some models
Carriage Types 4 Roller Carriage AX50 standard • Ok with forks or SS. & normal load widths • Option of 6 roller for all other attachments, long load centers or wide loads
Carriage Types 6 Roller Carriage AX
optional
BX
standard
CX
standard
Carriage Types How do we classify carriages? Class II – 16” – Up to 5,500 lbs. Class III – 20” – 6,000 to 10,000 lbs. Class IV – 25” – 11,000 lbs. Plus
Carriage Types
Increased roller span. Reduced roller load & roller surface pressure
Carriages What are the advantages of 6 roller? Lower surface pressure on load roller face and mast channel
Lower Moment
Higher Moment Force
Forks Hook type forks • Most common style • 3 typical sizes Dimensions Class II – 16” Class III – 20” Class IV – 25”
Forks
Pin or Shaft Type Carriage •Generally used on larger applications and larger capacity trucks such as EX models
Forks
Forks Standard taper pallet fork Typically a fork that has other than a full taper; commonly this is one-third of the fork blade length. Fork length should typically cover a minimum of 75% of the load length
Forks Fully polished & tapered Fully tapered bottom (from heel to tip) with a polished top surface
Other Fork Types Block fork Generally a narrow, almost square stock that will easily fit most concrete block. Lumber fork Typically thin, wide fork fully tapered and polished with a chisel tip IE: 1.5” x 10”. The increased width is necessary to maintain fork capacity. Gypsum or Sheetrock forks Generally common to the lumber fork with a rounded or bevel side edge and/or a padded vertical back to prevent product damage.
Fork Extensions
Forks
What is the rule of thumb on fork extensions vs standard fork length? 150% of the standard fork length. IE: 48” fork can support up to a 72” fork extension.
Stability
Stability of Forklifts • Forklifts can and will tip over if overloaded, or if they raise a full load higher than permitted • As a Sales Professional you should fully understand the static and dynamic principals of forklift trucks in order to recognize and assure safe operation
Stability of a Counterbalanced Forklift • The
fulcrum point of a counterbalanced forklift is the center of the drive axle
Fulcrum is drive tire
Load
Counterweight
Teeter Totter Principle • Forklifts work on the principle of a teeter totter. You have a pivot point (drive axle center) and counterweight (CW) at one end to offset the load weight (W). • Too much weight will cause it to tip over. (or) if you move the weight further out from the pivot or fulcrum point it will also cause tip over.
CW
Counterweight Makes All The Difference
Load Capacity • The load capacity of the forklift truck is a measure to indicate the maximum weight load that can be handled as a “load” on the forks at a given “load center” with the mast held in a vertical position •The load capacity rating is expressed in pounds (or kilograms) at the load center in inches (or millimeters) The chart of the load capacity is referenced from the operator’s seat on the truck’s data plate 500PG 5000 4400 3900 2800 2400
24 30
36
40
48
Load Center The load center is specified as the distance between the center of gravity of the load on the forks and the vertical front face of the forks.
Weight Distribution • Wheel loadings / weight distribution can be very important in applications where there are floor loading limitations – Elevators / multiple floor buildings / trailers
• Empty forklifts have most of their weight in the rear of the truck when unloaded • A forklift undergoes the greatest change in weight distribution when a load is placed on the forks – As much as 90% of the weight is shifted to the drive axle when the truck is fully loaded
Example of Wheel Loading of 400PG Front 3,740 lbs
Rear 3,300 lbs.
Total weight = 7,040 lbs.
3,740
3,300
Unloaded (Empty)
Front
Rear
10,340 lbs.
1,100 lbs.
Total weight = 11,440 lbs.
10,340
1,100
Loaded
Load Center
The horizontal distance between the face of the forks and the center of gravity of the load it is carrying is called the load center
Be Cautious of Long Load Centers! • Long load centers have a very detrimental effect on the forklift – It transfers more weight off of the rear axle causing truck instability and possibly tipover!!
• It is like placing an overload at the normal load center of the forks!! • Consult the factory for capacity ratings at extended load centers • Anything greater than a 24” load center will reduce truck capacity and have an effect on truck stability!!
Long Load Centers
Truck Center of Gravity HCG = Horizontal Center of Gravity The Center of Gravity of a forklift changes as the mast is tilted or raised. This is important since all forklift capacities are based upon the location of the C of G. This also changes the wheel loading on drive and steer tires. The illustration show the effect on the C of G as the mast is tilted forward or backward.
Truck Vertical Center of Gravity The illustration shows the effect on the C of G as the mast is raised or lowered. As you can see as the load weight moves up or down the VCG (vertical center of gravity) also changes.
Combined Center of Gravity • An empty forklift has a center of gravity and the load has a weight and its own center of gravity • When the truck picks up the load, the center of gravity of the truck shifts forward • As longs as the combined center of gravity of the truck and the load is located between the front and rear axles, the truck will remain stable • If the combined center of gravity of the truck and load is beyond the centerline of the front axle, the truck will tip over
Combined Center of Gravity
Dynamic vs Static Stability • Static stability is measured when the forklift is standing still • Dynamic stability is the transfer and shifting of the CG due to dynamic forces such as: – Traveling / braking / turning / lifting / lowering
The Stability Triangle
The Stability Triangle • Stability is the result of many factors – Wheelbase / overall width at the front axle / weight distribution / lifting height
• Stability refers to longitudinal and lateral stability, the stability triangle, and dynamic vs. static stability
The Stability Triangle • Point “A” = Center pivot point of the rear steer axle • Point “B” and “C” = Straight line between centerline of each drive axle
The Stability Triangle • When a load is placed on the forks, the center of gravity of the forklift moves forward • Ideally the CG must always stay within the stability triangle
The Stability Triangle • This diagram shows the effect of having the mast vertical and using a sideshifter • The load causes the CG to shift forward and sideshifting from side to sideshifts the CG to the right or left
The Stability Triangle • DANGER!! – Load is too heavy and too far out on the forks and the CG has shifted outside of the stability triangle!!
The Stability Triangle • Danger!! – The load is not stable and the heaviest part is out in front of the CG creating an unstable situation!!
The Stability Triangle • Danger!! – The load is not stable and the heaviest part to one side! When turning the momentum will shift further to the side creating a dangerous situation!! The truck could tip over laterally!!
Stability of Elevated Loads •
Tilt table tests determine at what point the truck becomes unstable and downrates the truck accordingly to maintain stability with elevated loads
To Maintain Truck Stability • Always use caution when – – – – – –
Lifting Tilting Turning Braking Traveling with an elevated load Traveling over uneven floor conditions
• Always keep the CG within the stability triangle!!
Tilt Table Testing • The rated capacity and stability factors of a forklift are determined by tilt table tests with criteria established by the ISO (International Organization for Standardization) and ANSI/ITSDF B56.1 • The static center of gravity is definitely not the final determinant of forklift stability
Capacity Ratings and the Data Plate
Truck Model
Data Plate Service Weight IC Attachment Attachment 2 Attachment 3 Service Weight Electric Battery Weight max. Battery Weight min. Battery capacity
Attachment Tire size
Lift Height
Vertical CG Capacity
Load center
Tilt Angles UL Type Serial Number
Importance of the Data Plate • • • •
Every truck must have an accurate, legible data plate Any approved modifications to the truck must be reflected on the data plate Data plates show both English measurements and metric No changes or modifications can be made to the truck without written approval from the manufacturer – Any change that effects truck stability i.e.an attachment, longer forks, etc. – Critical to meet OSHA regulations – A truck without an accurate data plate can be removed from service
Capacity of a Forklift •
Is determined by two factors – Weight of the load – Distance of the load’s center of gravity from the face of the forks
•
Almost all manufacturers of forklift trucks have standardized on rated capacities at 24” (600 mm) load centers for models up to about 30,000 lb capacity
•
The load center is the horizontal distance between the vertical front face of the forks and the center of gravity of the load
•
Therefore a 5,000 lb. capacity truck rated at a 24” load center can lift a load that weighs 5,000 lbs. that is 48” long provided the load weight is evenly distributed
Understanding Metrics Metric Standard 1500 kg @ 500 mm L.C. = 3,300 lbs @ 19.7 in L.C.
US Standard 3,000 lb @ 24 in L.C. = 1,360 kg @ 610 mm L.C.
Inch-pound Ratings A typical load capacity chart shows a forklift truck’s capacities at many load centers. These ratings take into account all dynamic and static stability factors. 500PG
5000 4400 3900 2800 2400 24
30
36
40
48
Lift Truck Performance & Specifications
Key Measurements • Discriminating buyers look closely at truck specs to compare competitors • How do we “measure-up” vs. the competition? • Key specifications: – Overall width / Overall length / Overall height / Head length / Under clearance / Wheelbase / Outside turning radius / Right angle stacking width / Travel speed / Lift speed / Lower speed
• Key individual specifications represent the forklift’s work capability and suitability for your customer’s application
Truck Dimensions
Truck Width • Truck width is a critical measurement because it effects the truck’s ability to work in specific areas such as: ¾ Go through doorways / Work in drive-thru / drive-in racking / bulk stack ¾ If the truck is wider than the load, bulk stacking more than one pallet deep could be a problem ¾The wider the truck, the greater the turning radius will be
Overall Height • Overall height is critical for working inside of trailers, box cars, and containers • Overall height is also critical for getting through facility doorways • Highest point could be OHG or mast – OHG height is usually fixed, mast could be variable
Wheelbase • The wheelbase does not relate directly to maneuvering dimensions (except grade under clearance), but it does affect truck behavior • A long wheelbase requires a greater angle of wheel steering and results in less efficient steering operation • The shorter the wheelbase the easier to steer
Length to Face of Forks • This dimension is important when figuring right angle stacking and dimensions for a working stacking aisle
Turning Radius • The turning radius is the radius of the smallest possible circle in which the forklift truck can turn • Turning radius is effected by overall truck width and steer angle
Under Clearances • The under clearances of the truck frame, mast, drive, and steering axles can be significant if there are surface irregularities or obstacles. • Not all under clearances are indicated on specification sheets. The mast clearance is generally the lowest point and, therefore, most often listed. • In backing up over bumps or obstacles, the rear (steer) axle clearance is important. Pneumatictire trucks have higher under clearances because they are intended for poor surface conditions
Grade Angle Clearance • The operator must know the truck’s
grade angle capability for operating on ramps or over dock boards and dock plates • The incline (in terms of percent) on which the center of the frame under clearance will just touch when the truck is going down from the level to the ramp or when the truck is going down from the level to the ramp or when the truck is going up from the ramp to the level is important • And the so called departure angle (from the wheel arc to the truck edge) of the counterweight is also essential. But, in most sales literature, gradeability is substituted for the grade angle
Grades and Gradeability How do we calculate grades and gradeability??
Note: Always drive backwards up a ramp
Gradeability How to Calculate A Grade Percent of Grade = vertical ramp rise / horizontal ramp length 0.20 = 20% Ramp Grade 20 4.0 4 ft
20 ft
Conversion Percent to Degrees Percent of Grade 25% 20% 15% 14% 13% 12% 11% 10% 9% 8% 7% 6% 5% 4% 3% 2% 1%
Degree of Ramp Angle 14.03 11.31 8.53 7.96 7.40 6.85 6.28 5.71 5.15 4.58 4.00 3.43 2.86 2.30 1.71 1.15 0.56
Calculating a Grade and Gradeability
Operator Restraints • Operator restraint systems are designed to keep an operator within the confines of the operator compartment in the event of a truck tip-over • Systems include: – Seat belts / Seats with hip or shoulder restraints / Hood latches / Battery restraints / Decals / Operator manual instructions
Industry Organizations
Industry Organizations ANSI B56.1 > American National Standards Institute ASME B56.1 2000 > The American Society of Mechanical Engineers ANSI/ITSDF B56.1 > Industrial Truck Standards Development Foundation • B56.1 is specifically for Powered and Non Powered Industrial Trucks • Develops Safety codes related to Powered Industrial Trucks – For Manufacturers – For End Users
Industry Organizations OSHA > Occupational Safety & Health Administration • Governmental Based OSHA's mission is to prevent work-related injuries, illnesses and deaths. Since the agency was created in 1971, occupational deaths have been cut in half and injuries have declined by 40 percent.
Your Responsibilities… • As a material handling professional you are obligated to point out any usage of our equipment that does not comply with OSHA to the company’s contact person…..safety is everyone’s responsibility • Offer your dealership’s services to provide required operator training
Your Customers Must Properly Train Their Operators • Required by OSHA • Promotes safe working environment • A well trained operator – Is far more efficient and productive – Puts safety first!!
Operator Training • OSHA Regulation:29 CFR 1910.178 • Regulation essentials – Training (Classroom & Hand-On) – Evaluation – Certification
• Regulation topics – Fundamentals – Forklift specific – Workplace specific
Operator Training Is the Law! • The employer must: – – – –
Train Evaluate Certify Must re-train when: • There is an accident • Near miss • Observed unsafe behavior
– Operators must be re-certified every three years – No exemption for temporary workers
Industry Organizations ITA > Industrial Truck Association
• • • • •
Comprised of Manufacturers & Associate Manufactures Board, Statistical, Engineering & Product Liability groups Develops common standards as guidelines Reviews legislation that impacts group members Gathers Statistical Data.
Classifications of Forklift Trucks in the U.S. Market
Class I
3-Wheel, 4-Wheel Sitdown Riders, Stand-Up Counterbalance Riders
Class II Narrow Aisle Reach Trucks, Order Selectors, Turret Trucks
Class III
Walkie & Walkie/Rider & Center Control Pallet Trucks,Tow Tractors, Walkie Stackers
Used for trailer loading/unloading, indoors in plants & warehouses where good maneueverability is needed Used in warehousing & distribution for high level storage and high level orderpicking in narrow aisles Walkie trucks are utilized in a wide variety of manufacturing & warehousing applications
Classifications of Forklift Trucks in the U.S. Market (cont.) Class IV
Engine Powered, Cushion Tire, Sit-down Rider Forklifts
Class V Engine Powered, Pneumatic Tire, Sit-down Rider Forklifts
Indoor use on loading docks in plants & warehouses where power & continuous usage are expected & good maneuverability is important Outdoor use for load handling in retail, lumber, shipping & stevedoring where power and continuous usage is expected
Industry Organizations UL > Underwriters Laboratory Underwriters Laboratories Inc. (UL) is an independent, notfor-profit product safety testing and certification organization. Each year, more than 17 billion UL Marks are applied to products worldwide. Generally electrical and fuel related validation.. Trucks must be manufactured in compliance with U.L. U.L. 558 applies to internal combustion engine forklifts U.L. 583 applies to battery powered electric forklifts
Industry Organizations NFPA > National Fire Prevention Agency NFPA 505 – 2006 • NFPA distinguishes forklift types in accordance with their suitability for use in special environments which present the risk of fire or explosions • NFPA regulations cover designations, areas of use, maintenance and operation • Electric Forklift Classifications: – Type “E” / Type “ES” / Type “EE” / Type “EX”
• Engine Forklift Classifications: – Type “G” / Type “GS” / Type “LP” / Type “LPS” / Type “D” / Type “DS” / Type “G/LP” / Type “GS/LPS” / Type “DX” Diesel explosion proof
Industry Organizations NFPA > National Fire Prevention Agency NFPA 505 – 2006 • NFPA states that hazardous work areas must be properly marked showing the type of truck classification that must be used in that special area • It is the customer’s responsibility to communicate these special application needs and need to operate the forklift within a hazardous area
Industry Organizations MHEDA >Material Handling Equipment Distributors Assoc. • Dealer based Organization • The Material Handling Equipment Distributors Association is the only trade association dedicated solely to improving the proficiency of the independent material handling equipment distributor. • MHEDA is your direct connection to the Material Handling Industry's hottest trends, newest products and best management training workshops. MHEDA represents a wealth of resources for all material handling businesses.
