Special Purpose Vehicle

1. SPECIAL PURPOSE VEHICLES
Topic : FORKLIFT

2. Introduction
• A forklift (also called lift truck, jitney, fork truck, fork hoist, and forklift truck)
is a powered industrial truck used to lift and move materials over short
distances.
• The forklift was developed in the early 20th century by various companies,
including Clark, which made transmissions, and Yale & Towne Manufacturing,
which made hoists.
• Forklifts have become an indispensable piece of equipment in manufacturing
and warehousing.

3. General operation of forklift
• Forklifts are rated for loads at a specified maximum weight and a specified
forward center of gravity. This information is located on a nameplate provided
by the manufacturer, and loads must not exceed these specifications.
• An important aspect of forklift operation is that it must have rear-wheel
steering. While this increases maneuverability in tight cornering situations, it
differs from a driver’s traditional experience with other wheeled vehicles.
• While steering, as there is no caster action, it is unnecessary to apply steering
force to maintain a constant rate of turn.

4. • Another critical characteristic of the forklift is its instability. The forklift and
load must be considered a unit with a continually varying center of gravity
with every movement of the load.
• A forklift must never negotiate a turn at speed with a raised load,
where centrifugal and gravitational forces may combine to cause a disastrous
tip-over accident.
• Forklifts are powered by electric battery or combustion engines. Some
Forklifts allow the operators to sit while driving and operating the machine
while others require the operator to stand.

5. Types of forklift
• Pedestrian Operated Pallet Trucks
• Telescopic Handler Forklifts
• Industrial Side Loader Forklifts
• Rough Terrain Forklifts
• Industrial Counterbalance Forklifts

6. Components
1. Truck Frame
Truck Frame is the most vital component which forms the
base of the machine. All of the key components of the
forklift including wheels, counterweight and mast are
attached to the truck frame.
2. Counterweight
• The Counterweight is a cast iron weight attached to the
rear part of the forklift. The aim of the counterweight is
to counter balance the load that is being lifted. On
Electric Forklift, Counterweight is fixed to the lead-acid
battery.

7. 3.Power Source
• The forklift’s power source consists of an internal
combustion engine. The engine can be fueled by
LPG, CNG, diesel and natural gas. Electric Forklifts
derive power from fuel cells or Lead Acid
Batteries.
4. Carriage
• The carriage serves as the base to the forklift. The
Carriage is fixed on mast rails so that it can be
easily moved upward and downward.
5. Mast
• The Mast is a vertical part that lifts up and pushes
down the loads. The Mast component consists
of Interlocking Rails that offers horizontal control.
Like Carriage, Mast may be equipped with rollers.

8. How a Forklift Works?
Forklifts derive their power from two entwining mechanisms:
• A Pair Of Hydraulic Cylinders
• A Pair Of Roller Chain Pulleys
• Controls

9. Lifting Mechanism: Hydraulic Cylinders
• The lift handle is attached to an electrical air pump at the base of the forklift.
Once the handle is pressed, it triggers the air pump that draws the outside air
through a filter and forces it into a tube reaching to the hydraulic cylinders.
• A hydraulic cylinder comprise of a hollow tube closed at one end with a flexible
lubricated piston fitting into the other. Air gets entrapped through the base of
the cylinder that allows gasses to enter without leaking them out.
• The volume of gas in the cylinder raises the pressure inside it. The pressure
applied to the area of the piston head generates an upward force.
• This force causes the piston to move up, increasing the volume of the gas and
minimizing the pressure.
• It creates physical equilibrium at the forklift height and an equivalent force
from the Gas and the Forklift’s Load.

10. Application
• Construction Sites
• Industrial Forklifts serve as very useful equipment at the construction sites, as it can
be used to carry hefty building materials over long distances, across the rough terrain
• Warehouses
• Forklifts are most often used in the warehouses. Forklifts are mainly used for loading
and unloading trucks and for carrying goods.
• Recycling Operations
• Forklifts are also used in recycling operations for unloading the recycling trucks or
containers and transporting their contents to the sorting bays
• Dockyards
• heavy duty forklifts are being used to transport bulky containers from delivery trucks
to dockside storage regions and then to ships

11. THANK-YOU