In today’s world , technology is used in every industry. In manufacturing electrical appliances, clothes and even the food we eat, – technology is everywhere. Moreover, it is impossible to imagine modern society without cars. Everyone wants to have a car because it is convenient, helps save time and ends our dependency on public transport. However, the increase in the number of cars on the streets has its own problems, namely, a lack of parking space. Multilevel parking and parking lifts are the solution, allowing for a large number of cars to be parked in a smaller area. However, some car owners are afraid of using car lifts as they worry about the safety of their cars. In order to stop worrying it is necessary to understand how car lifts work.
Currently the most common car lifts are electromechanical and electrohydraulic. Both systems have advantages and disadvantages, but they ensure the safety of parked cars equally well. First, let us consider electromechanical systems. The screw mechanism that performs the rise and the descent of the platform serves protection against accidental lowering of the platform. This mechanism is designed with a self-locking system. It means that if the platform falls, it will not accelerate and damage the car below because the descent will slow down.
The electro-hydraulic lift system is somewhat more complicated. To be precise, there are two systems providing the safety of cars: hydraulic and mechanical. If the hydraulic system fails, a safety valve mounted at the inlet of the hydraulic cylinder prevents a spontaneous lowering of the platform.
The scheme of a mechanical system of electrohydraulic lifts is shown in Figure 1. Spring-wedge mechanisms are mainly used in such lifts. The safety strap 4 fixed inside the rack and a spring-loaded locking wedge 3 which swings on the shaft are the base of the mechanism. The lift and the descent of the platform are regulated by the wedge. While the platform is lowering or lifting, the wedge 3 is withdrawn from the safety strap 4 at a distance of 5-8 mm. When the button is released the wedge enters the opening of the safety strap and makes it impossible for the platform to move.
Still, accidents do happen and what if an accident such as the breakage of the pull rope, for example occurs? Even in this case you don’t need to worry about your car. If the pull rope 5 breaks off, the beam 1 makes a turn and presses a button that disables hydraulic drive 2. This actuates the locking wedge 3. At this point the wedge 3 enters the opening of the safety strap 4 and the movement of the platform becomes impossible because its position is fixed.
As you can see, the designers have taken care of the safety of cars parked on the lifts. In addition, security systems are improved with each new model of lifts, so you can be absolutely sure about the safety of your car.
Figure 1. Wedged safety system of electrohydraulic lifts. 1 – beam; 2 - hydraulic drive power button; 3 – wedge; 4 – safety strap; 5 – pull rope.