Sendhamarai Engineering is providing FORKLIFT for their customers in very special way with the mechanism of forklift’s working so that they know how to maintain the machine. The hydraulic pistons are attached to the two main vertical structures called the “masts.” However, the actual forks that carry the load are attached to the main body of the forklift through a pair of roller chain pulleys whose fulcrum is a gear at the top of the mast.
Thus, when the hydraulic pistons push the masts up, the gears on the masts push against the roller chains. Because one side of the chains are attached to the immobile frame of the forklift, the only way the masts can move up is if the gears rotate clockwise and pull the forks up.
The importance of this mechanism is that it allows the forks go far beyond the reach of the cylinders alone. If it weren’t for the roller chain pulleys, forklifts would need much taller cylinders to lift loads to a comparable height. Taller cylinders would mean more building material, which would shift the vehicle’s centre of gravity forward and increase the risk of tipping. Likewise, taller cylinders would demand stronger pumps and higher pressure thresholds.
Controls
Forklifts have two sets of controls: one for steering and one for lifting. The steering controls work much like those of a golf cart: acceleration pedal, brake, steering wheel, forward gear and reverse gear. However, unlike a car or golf cart, forklifts use rear-wheel steering–when you turn the steering wheel, the wheels on the rear axle turn back and forth. This design is intentional: rear-wheel steering allows the driver a greater degree of rotation and precision when handling a load.
The lifting controls consist of two levers: one for lifting the fork up and down as well as one for tilting the load back and forth. The lifting functionality works as discussed above–forward moves up and backward moves down. The tilting functionality, however, is slightly different. At the base of the masts are two pairs of additional hydraulic cylinders that attach to the base of the vehicle. When the “tilt” handle is moved forward, air is pumped into the chamber. This increase in pressure pushes the piston head and causes the masts to “lean away” from the vehicle’s body.
When the “tilt” handle is moved back, air is slowly released from this cylinder as air is pumped into the other pair of mast-attached cylinders. When the pistons from the latter pair push forward, the masts are rocked back toward the vehicle.
