Mobile column lifts are the most versatile of the many types available for heavy duty applications. They require no installation. They have sufficient capacity to lift any vehicle in the fleet. They do not require a dedicated bay. And, they can be used wherever a suitable foundation and power are available.
Many new mobile lift models have appeared on the market in the past few years, and given their common and fairly simple operation (they raise and lower) manufacturers have sought ways to distinguish their lifts from the others. This has lead to a number of alternate designs, beginning with hydraulics, and now includes higher lifting capacity, weighing capability, adjustable forks, battery power, and wireless control. Each alternate is worth considering, and in some applications one or more might be useful, but purchasers should not overlook the fundamental design of the lift. It is still the most important consideration.
Early mobile lifts had mechanical screw type drives for reasons that continue to make them the best choice today. They are self-synchronizing and their design facilitates the use of redundant safety systems.
Mobile lifting systems with screw type drives have a natural tendency to keep vehicles level because their drives operate at a constant and uniform speed regardless of the load differential between axles. Columns with heavier loads draw more current, but continue to operate at a uniform speed. Thousand of mechanical mobile lifting systems have been built that depend cột đèn cao áp - chieusangngoaitroi.com
, solely on this characteristic along with the attention of a careful operator. In the recent past, electronic synchronizing controls have been added to screw type lifting systems as a redundant safety measure.
Redundant safety is also found in high quality screw type mobile lifts to sustain raised loads. In ball screw lifts, spring set load brakes have the primary load holding responsibility. The brakes are normally engaged and released only when power is applied to raise or lower the lifts. Redundant safety is provided by wedge locks that are independent of the lifting mechanisms and engage directly with the columns.
Other factors that determine whether a mobile lift belongs in the "best choice" category are ease of use and durability. The lifts should be easy to set up, and easy to use. Columns should be identical to eliminate the need to position them in any particular order. They should have a pallet style jacking device that can raise them high enough to roll easily over rough floors and ramps. Their interconnecting cables should be identical for convenience, and each cable should have a quick disconnect plug on each end. The cables should connect the columns in a "U" shaped pattern to leave an open end for vehicle access. Controls should be easy to understand and easy to use. Operating the lifts should require no more than connecting the columns together, turning the system on, and engaging the Up or Down push buttons. Controls that require complex
input from the operator lack thoroughness in their design.
Durability is hard cot chieu sang
to gauge by examining the lifts or by a short term demonstration. To deal with this, some have offered higher capacity lifts as a marketing ploy
to suggest their lifts are more durable than others. Who wouldn't believe that an 18,000 pound capacity column will last longer than a 16,000 pound capacity column in the same application? One might generally expect this to be true except when the higher capacity columns use synthetic materials for the carriage guide rollers rather than steel. Purchasers who want long dependable service from their lifts should demand steel guide rollers.
Paul Hoffman - President