Characteristics and purpose of auto jacks
A car jack is a special mechanism with a narrow focus and is used in two cases:
It is necessary to repair a vehicle (Vehicle) without supporting it on the wheels.
Changing wheels directly at the site of the breakdown
Light weight, mobility and reliability of the structure, as well as the ability to lift a vehicle on almost any terrain – these are the brief characteristics of a high-quality modern jack. Thanks to the wide range of technical and design features of the lifting mechanism, its use is equally easy for ordinary car and truck drivers, as well as in specialized transport enterprises (service stations, tire service).
Main characteristics of jacks
Regardless of the type of design of the lifting mechanism, its key characteristics remain unchanged, and it is to them that you should pay attention first of all:
Load capacity. The maximum weight that the jack can lift
Hmin or initial (minimum) lifting height. This parameter determines the lowest point from which the vehicle can be lifted. When choosing a mechanism, it is necessary to take into account the ground clearance of your vehicle.
Hmax is the maximum lifting point or maximum lifting height. This parameter is responsible for the highest point in height to which the jack can lift a car.
Support platform. This is the lower part of the lifting mechanism, responsible for its stability on the surface
The execution of the jack (the upper part of the mechanism, resting on the car to lift it) is not of decisive importance. Why? In any possible design, the manufacturer initially includes an adequately functioning jack that fully performs its functions. You may also come across such a parameter as Lmax (maximum working stroke of the jack). This characteristic is essentially a combined indicator of Hmin and Hmax, but in technical terms, Lmax determines the movement of the jack in the vertical plane from the minimum (lower) to the maximum (upper) position. Simply put, this is the range of vehicle lifting height.
What types of jacks are there? Differences and purpose
There are several main types of jacks, and their classification is determined by the type of design. Let’s consider each of them in more detail.
Screw jacks
These lifting mechanisms are most popular among ordinary drivers. Firstly, because the brightest representative of screw jacks, namely the diamond-shaped one, is equipped with new passenger cars. And secondly, the affordable price of these mechanisms makes them people’s favorites. Screw jacks are available in two types:
Rhomboid jack
Suitable exclusively for passenger cars, since its maximum load capacity is within 2 tons, and the minimum and maximum lifting height varies between 50-470 mm.
Pros:
Inexpensive, lightweight, compact, simple and reliable lifting mechanism.
Cons:
Narrow support platform, due to which the structure is prone to collapse.
Telescopic jack
The bottle-shaped shape of the product and the square support platform form a low center of gravity, which is why the telescopic screw jack is more stable than the diamond-shaped one. But it is worth considering the vertical dimensions of the mechanism, since the lifting height is greater than that of the diamond-shaped one, which means that the design will not fit under every car.
Screw “telescopes” are often used, bypassing the direct purpose of the jack, and with their help they compress springs, dismantle wheels, and in special cases are even used in body repair.
Rack jacks, high-jack, high-lift
Low lifting height, high lifting height (up to 1.5 m) and the ability to lift equipment weighing 15 tons and more – sounds like the best lifting mechanism. But not everything is so smooth. Firstly, the rack jack is quite large, and secondly, it has a special specificity of use. Basically, such mechanisms are used in cases where it is necessary to pull out a large vehicle stuck in the mud (agricultural machinery, SUVs, etc.). They are often used by construction workers.
Хидравлични крикове
Unlike mechanical jacks, which require significant physical effort, hydraulic jacks lift weights with minimal tension, using the principle of fluid pressure, usually hydraulic oil. This method makes lifting vehicles or other heavy loads much easier and more efficient.
Types of hydraulic jacks
There are several main types, each of which is designed for different needs:
1. Single-piston (Bottle) jacks
These are the most common hydraulic jacks, often called “bottle” because of their shape. They are standard equipment in many light and heavy vehicles, as well as in construction equipment. They operate with a single piston and are known for their reliability and compactness.
2. Telescopic Jacks
Telescopic jacks are improved single piston jacks.
l jacks that have additional, retractable pistons. This “telescopic” design allows them to achieve a much greater lifting height than standard models, while maintaining an impressive load capacity.
3. Crocodile-type jacks
Also known as “crocodile”, this type of jacks is extremely popular in car repair shops. They have a low profile and are equipped with wheels, which allows them to quickly slide under the vehicle. Thanks to the long lever and efficient hydraulic system, they can lift a car in a matter of seconds.
The main advantages of hydraulic jacks include the following factors:
- good stability;
- high load capacity (up to 200 tons);
- compactness and smooth running;
- requires little effort on the drive handle;
- very good efficiency of the mechanism within 80%.
The disadvantages include one rather banal thing. The complexity of the design (compared to mechanics) slightly hints at laborious repairs in the event of a breakdown.
Pneumatic jacks
This, at first glance, unremarkable “inflatable cushion” pleasantly surprises with its operational characteristics and functionality. Along with hydraulic jacks, pneumatic jacks are often used in repair shops and tire shops. The advantages include load capacity (up to 5 tons) and the ability to lift vehicles with low ground clearance. The disadvantages include, perhaps, the price, since pneumatic jacks do not belong to the budget class of lifting mechanisms.
How to choose a jack for a vehicle
The easiest and most effective way to choose a jack by load capacity is to resort to a simple calculation formula:
A – vehicle weight
B – vehicle load capacity
A + B = minimum values of the lifting mechanism. Example: the car weighs 1.2 tons, the maximum permissible mass of additional weight is 0.45 tons. Calculation: 1.2 + 0.45 = 1650 kg required lifting capacity of the jack (minimum). When choosing, be sure to take into account the height of the vehicle’s ground clearance and the technical characteristics of the initial lifting height of the lifting mechanism. And do not forget about Hmax (maximum lifting height), so that it does not happen that when the jack is fully raised, your wheels do not lift off the ground.
And, of course, you should not resort to excessive savings when buying a jack. Since poor-quality device can cause irreparable harm to your health or, at the very least, damage your car during operation.
