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How Does a 2-Post Above Ground Lift Work?

The 2 post car lift was designed in order to lift vehicles and trucks to allow ease of accessibility to the wheel assembly as well as the underneath of the car. A two-post over ground lift typically attached to the concrete surface that is already in place. The minimum depth of concrete required for a two-post over ground lift of 4 inches. A greater amount of concrete is needed for two-post lifts that exceed 12,000 lbs. capacity.

The lift is comprised of two upright columns with four adjustable arms connected to an assembly for carriages and two hydraulic cylinders an electric/hydraulic power unit as well as a variety of pulleys, hoses, and cables. It is by far the most typical design of two-post above ground lift that is found within the UK. There are also a few European companies that manufacture above ground lifts , which use an extruded screw/nut design driven by an electrical motor.

The two-post above-ground lift was created for automobile facilities that could not install lifts in the ground. A lot of automotive service facilities are constructed on top of rock (and excavation is either impossible or not feasible) or on properties with a large level of groundwater. Two post above ground lifts are the ideal choice for replacing an unusable ground lift, which will avoid downtime as well as the cleanup and removal mess that comes when an in-ground lift is installed.

The majority of two post above ground lifts run on an electrical or hydraulic power unit.

Power units are made up comprising the following major components:

The electric motor (usually two-phase single phase 220 Volt 60 HZ). The ideal electric motor must have the highest torque while drawing the lowest amount of amperage. A motor with a high horsepower does not confer any advantages over a less powerful motor that delivers the same amount of torque.

Hydraulic pump installed below the motor unit (with a pre-set valve pressure limit)

Plastic reservoir to hold the hydraulic fluid

Dump valve handle allows the flow of hydraulic fluid into the reservoir through the hydraulic system.

If the button is activated, the electrical/hydraulic power unit releases hydraulic fluid that is pressurized (through Hydraulic pipes) through the two hydraulic cylinders (one is in each of the columns). Hydraulic fluid pressure is controlled through the factory-set valve for pumping.

The hydraulic fluid that is pressurized is delivered to both hydraulic cylinders by the hydraulic hoses. The hoses are connected either above the upper part of the hoist (through an overhead beam that is found on the overhead two posts above the ground hoist) or onto the ground (covered by the base plate of diamonds located on the base plate 2 posts higher than ground liftings). The hydraulic fluid is not moving in the same speed as light. The hydraulic cylinder in the “smart” column (the column that has the power unit mounted) will be receiving hydraulic fluid prior to the cylinder that is on the “off” column.

In order to ensure that both carriages as well as the four arms are moving simultaneously, equalization cables is inserted within the arms between them. The equalization cables are connected exactly the same way similar to the hydraulic lines. The equalization cables don’t lift the carriages. Equalization cables are employed to ensure that the arms are all level and that locks within each column are working simultaneously. Yes, the cables exert pressure and exert “force” upon the wheels but their primary function is to balance the descent and rise of lift arms (carriages). The pistons with hydraulically-pressurized pressure (encased within those twin hydraulic cylinders) are the ones responsible to lift the car. Some manufacturers employ an equalization system that is hydraulic. It is our opinion that using the equalization of aircraft cables system gives the best results . We use this method only on the two posts higher than groundlifts.