A pallet jack, also known as a pallet truck, pallet pump, pump truck, dog, or jigger is a tool used to lift and move pallets. Pallet jacks are the most basic form of forklift and are intended to move heavy or light pallets within a warehouse. The jack is steered by a ’tiller’ like lever that also acts as the pump handle for raising the jack. A small handle on the tiller releases the hydraulic fluid, causing the forks to lower. The front wheels inside the end of the forks are mounted on levers attached to linkages that go to levers attached to the jack cylinder. As the hydraulic jack at the ’tiller’ end is raised, the links force the wheels down, raising the forks vertically above the front wheels, raising the load upward until it clears the floor. The pallet is only lifted enough to clear the floor for subsequent travel. Oftentimes, pallet jacks are used to move and organize pallets inside a trailer, especially when there is no forklift truck access or availability.
Powered pallet jack
An electric pallet jack. The recharging lead can be seen.
Powered pallet jacks, also known as electric pallet trucks, walkies, single or double pallet jacks, or power jack, are motorized to allow lifting and moving of heavier and stacked pallets. Some contain a platform for the user to stand while moving pallets. The powered pallet jack is generally moved by a throttle on the handle to move forward or in reverse and steered by swinging the handle in the intended direction. Some contain a type of dead man’s switch rather than a brake to stop the machine should the user need to stop quickly or leave the machine while it is in use. Others use a system known as “plugging” where in the driver turns the throttle from forward to reverse (or vice versa) to slow and stop the machine, as the dead man’s switch is used in emergencies only.
Reversible pallets cannot be used.
Double-faced non-reversible pallets cannot have deck-boards where the front wheels extend to the floor.
Enables only two-way entry into a four-way notched-stringer pallet, because the forks cannot be inserted into the notches.
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. In many jurisdictions it is illegal to alter or remove the nameplate without the permission of the forklift manufacturer.
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.
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. The forklift is designed with a load limit for the forks which is decreased with fork elevation and undercutting of the load (i.e., when a load does not butt against the fork “L”). A loading plate for loading reference is usually located on the forklift. A forklift should not be used as a personnel lift without the fitting of specific safety equipment, such as a “cherry picker” or “cage”.
Forklifts are a critical element of warehouses and distribution centers. It’s imperative that these structures be designed to accommodate their efficient and safe movement. In the case of Drive-In/Drive-Thru Racking, a forklift needs to travel inside a storage bay that is multiple pallet positions deep to place or retrieve a pallet. Often, forklift drivers are guided into the bay through guide rails on the floor and the pallet is placed on cantilevered arms or rails. These maneuvers require well-trained operators. Since every pallet requires the truck to enter the storage structure, damage is more common than with other types of storage. In designing a drive-in system, dimensions of the fork truck, including overall width and mast width, must be carefully considered.
Dedicated container forklift of the HMNZS Canterbury vessel of the New Zealand Navy
Forklift control and capabilities
Forklift hydraulics are controlled either with levers directly manipulating the hydraulic valves, or by electrically controlled actuators, using smaller “finger” levers for control. The latter allows forklift designers more freedom in ergonomical design.
Forklift trucks are available in many variations and load capacities. In a typical warehouse setting most forklifts have load capacities between one and five tons. Larger machines, up to 50 tons lift capacity, are used for lifting heavier loads, including loaded shipping containers.
In addition to a control to raise and lower the forks (also known as blades or tines), the operator can tilt the mast to compensate for a load’s tendency to angle the blades toward the ground and risk slipping off the forks. Tilt also provides a limited ability to operate on non-level ground. Skilled forklift operators annually compete in obstacle and timed challenges at regional forklift rodeos.
Efacec Handling Solutions S.A. offers wide range of Automated Material Handling Equipments includes Conveyors, Warehouse Management System, (telescopic forks, satellites, box retrievers), Material Flow Control / Warehouse Control System, PLC controls, High speed Miniloads, Stacker cranes (single mast, double mast, with aisle switching or transfer car option), Automatic Overhead Cranes, SCADA Supervision System, In rack Overhead Stacker Cranes.