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Home ยป The Mechanics of 2 Post Lifts

The Mechanics of 2 Post Lifts

Two post over ground lift can be designed to elevate trucks and cars to provide ease of acces to wheels as well as the underneath that the automobile is. Two post above the ground lift typically installed on the concrete surface that is already in place. The minimum depth of concrete needed for a two-post over ground lift of 4 inches. The use of a thicker concrete is recommended for two-post lifts that exceed 12,000 lbs. capacity.

The lift is comprised of two upright columns and four arms that can be adjusted to an assembly of carriages and two hydraulic cylinders an electric/hydraulic power unit and a range of pulleys and hoses and cables. They are the most typical type of two post car lift found within the UK. There are also a few European companies that manufacture above-ground lifts using an extruded screw/nut combination that is powered by an electric motor.

The two-post above-ground lift was created to assist automotive establishments that could not install lifts in the ground. Many of the automotive service centers are constructed on top of rock (and excavation is not feasible or not feasible) or are located on properties with a large surface water table. The two-post above ground lifts is an ideal option for replacing an unusable ground lift, thus avoiding downtime as well as the cleanup and removal mess that comes by an in-ground lift.

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

It is made up of the following principal 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 that is high-powered does not confer any advantages over a motor with a lower horsepower that delivers the same amount of torque.

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

Plastic reservoir to hold the hydraulic fluid

The dump valve handle is used to allow the hydraulic fluid to flow into the reservoir via the hydraulic system.

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

The hydraulic fluid that is pressurized is delivered to both hydraulic cylinders by the hydraulic hoses. These hoses run either on upper part of the hoist (through an overhead beam on an overhead two-post above the ground hoist) or down the flooring (covered by the base plate of diamonds that is found on the base plate posts over ground hoists). 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 connected) 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, an equalization cable are installed in between both carriages. The equalization cables are routed exactly the same way like the lines for hydraulics. The equalization cables don’t perform the lifting of carriages. Equalization cables are employed to ensure that the arms are all level and that locks in both columns are engaged simultaneously. The cables do apply pressure and exert “force” upon the wheels but their primary function is to balance the descent and rise of lift arms (carriages). The pistons that are hydraulically pressurized (encased within those twin hydraulic cylinders) are the ones responsible to lift the car. Certain manufacturers utilize an equalization system that is hydraulic. It is our opinion that using the use of the aircraft cable equalization system delivers the most favorable results . We use this method only on the two posts elevated lifts.