Lift table capacity ratings are based on an evenly distributed load positioned on the lift table platform during raising and lowering.
Wherever possible the loads center of gravity should be positioned on the platform centrally located over the lower frames width and length. An evenly distributed load on the platform ensures that all moving components such as bushings, bearings and leg rollers are equally and squarely loaded and will wear evenly.
Loads that are not evenly distributed on the platform are referred to as off-center loads. Off-center loads can lead to premature component wear when the lift table is cycled repetitively.
Off-center loads that are positioned towards the ends of the platform are less harmful than off-center loads that are positioned towards the sides of the platform. The weight of the off-center load positioned towards either end of the platform is evenly distributed by both the lower left and lower right scissor leg assembly.
An off-center load that is positioned towards either side of the platform puts excessive downward forces on either the left or right scissor leg assembly which can result in premature component wear that could ultimately lead to component failure.
With an off-center side load instead of both the left and right scissor leg sharing and supporting the load evenly the majority of the downward forces are absorbed by one side of the scissor leg assembly which could cause the scissor leg assembly to twist or bend. In addition to premature bushing and bearing wear this scissor leg twisting/bending effect can cause side loading on the cylinders accelerating the piston/seal wear.
An off-center load that is positioned towards the side of the platform can also cause permanent platform deflection and create a situation with a potentially dangerous unstable load.
In summary an application that requires off-center loading can benefit from choosing a lift table with a much higher capacity rating than one designed for an evenly distributed load. This is because an off-center load places uneven stress on the lift table structure, a higher capacity rated lift table will prolong the safe and efficient operation of the lift table in this application.
Additionally, notification and provision of details to the manufacturer of off center loads during the quoting process can accommodate consideration for designs and configurations of lifts that are more conducive to the off center load.
For additional information please contact the Pentalift Sales Department.