A jack is a mechanism whose main function is lifting and securing loads at heights. In the role of the difference between this device and other lifting mechanisms by the type of cranes and winches, it is possible to highlight the possibility of placing the equipment from below, and not from above, which eliminates the need for auxiliary ropes, chains and structures.
The main types of jacks
Today there are several varieties of jacks, among them:
- screw;
- rack and pinion;
- hydraulic;
- pneumatic.
The former are used for repair work, when there is a need to install the load on top or bottom. In this case, a rotating heel or paw can be used. The carrying capacity of such devices usually does not exceed 15 tons. Units consist of a cylinder, inside of which several or one lifting screw is placed. It can be extended or retracted, depending on the direction of rotation of the gear nut.
Considering the types of jacks, photos of which are presented in the article, their main advantages should be highlighted. For example, a screw device has the greatest reliability during operation, due to the fact that the load is strengthened by thread, and when lifting, the nut rotates idle. Important advantages can also be called stability, as well as durability, such mechanisms are able to work without additional supports.
When considering screw jacks, the types of this equipment you should study first of all. Among others, it is necessary to highlight combined lever-screw devices, which have an important advantage, expressed in low cost, impressive lift height, low weight and compact size. We should also mention the disadvantages of this type of screw jacks, among which - poor stability, as well as a drive handle, which is not convenient for use.
More on Lever Screw Jacks
The main types of jacks for cars include lever-screw devices, which are considered the most functional and are used to lift loads up to 1 ton. Among the advantages are light weight, high working stroke and low starting height.
However, these structures cannot boast of impressive rigidity, as well as stability. If it is necessary to lift a load, the mass of which reaches 2 tons, then a rhombic variety should be preferred, in the set of which there are 4 levers interconnected by hinges. They are located in the shape of a rhombus, which gave the name to the device.
More information on screw jacks
Car jacks, the types and purpose of which were described above, can be screw, they, by the type of application of effort, are divided into manual and equipped with an electric drive. The mechanical variety of such devices was invented 30 years ago, but to this day the mechanism has not undergone almost any changes.
The body and screw, which are made of steel, acts as the main structural element. The main advantages of such units have been described above, however, they also have disadvantages, among them:
- large size;
- small area of bearing;
- the ability to use exclusively when lifting cars equipped with eyes.
If we consider in more detail the insignificant area of bearing, then we can highlight the consequence, which is low stability. That is why such types of mechanical jacks are additionally insured with logs, as well as with all kinds of objects like bricks, which are placed under the car.
Characteristics of rack jacks
These tools are widely used in the installation and dismantling, as well as repair and construction works. Among the main varieties of this equipment, gear and lever mechanisms can be distinguished . The latter are complemented by a swinging lever that moves the rail. Instead of a drive lever, a gear is used in the gear rack jacks, which is driven by a handle. To hold the load on the axis of one of the gears, a ratchet is provided.
In both varieties of the described jacks, the load-carrying rail with a cup acts as the main unit. If the load has a low supporting surface, then just a rack jack will help in this, the lower end of the rail of which is bent at an angle of 90 °. Considering the types and types of jacks, you can note that an important feature of rack and pinion devices is the low location of the lifting platform. On sale you can find options in which the distance to the floor is only 90 mm. Such equipment may have one-, two- or three-stage gear. Each variety is used to lift loads:
- up to 6 tons;
- from 6 to 15 tons;
- more than 15 tons, respectively.
Such devices can operate in a vertical or horizontal position. The devices are easy to maintain and structurally simple, maintainable, and also provide high load capacity, which reaches 20 tons.
Hydraulic jack specifications
The next thing to consider is a hydraulic jack, the types of which will be mentioned below. This equipment works at the expense of liquid, and the principle of operation is based on a plunger, which is moved by pressure with liquid. Such devices are characterized by low working effort, high carrying capacity, high efficiency, compactness, smooth running and rigidity.
However, there are also disadvantages, expressed in an impressive lifting height, which is greater than that of mechanical jacks. The lowering height in this case cannot be adjusted as accurately as possible. In addition, these types of jacks can break, and breakdowns will be more serious than with lifting mechanical devices. The carrying capacity in this case varies from 1 to 1000 tons, and among the main varieties can be distinguished:
- bottle;
- classic
- rolling;
- rhombic;
- filling;
- two-level.
Considering the types of hydraulic type jacks, you will realize that the single-rod bottle type is easy to operate, has a wide area of use and allows you to efficiently perform work of arbitrarily high complexity.
You can use such equipment for dismantling and installation in any industry by type of construction and engineering. A jack will also come in handy when repairing railway cars, cars, wheelsets, as power units of pipe benders, pipe cutters and other equipment. These types of jacks should be transported with extreme caution, because the working fluid can simply leak out of the tank, so the device must be stored in an upright position.
Characteristics of pneumatic jacks
This type of equipment is used to lift and move cargo during repair, installation and rescue operations. Such devices are indispensable when there is a very small gap between the load and the support. The pneumatic variety of jacks is indispensable when the most accurate installation is required. If the work is carried out on marshy, uneven and loose soil, then the choice will be obvious.
These types of jacks are used for joining pipe systems of impressive diameters, sometimes this parameter reaches 1200 mm. Such equipment has the form of a rubber-cord flat shell, which is made of reinforced fabric. It increases in height when compressed air is supplied. The source can be mobile or stationary compressors, compressed air cylinders, automobile pumps.
The main disadvantage of pneumatic jacks is the impressive cost, which is affected by expensive manufacturing technology, design complexity, as well as small batches of industrial production. Considering such jacks, the types and design of which should be studied by you before buying, it should be mentioned that such devices may be unsafe when the engine is turned off. As for load capacity, it is determined by the pressure in the pneumatic actuator.
Characteristics of mechanical rack jacks
Considering the types of jacks for cars, it is worth highlighting rack-mount mechanical devices, in the design of which there are screws capable of lifting loads up to 3 tons. Such designs have high rigidity and excellent stability, but among the flaws there is a serious impressive weight and low lifting height.
Rolling jack and its main varieties
Considering the types of rolling jacks, portable, stationary and mobile devices should be distinguished. These mechanisms may have a different design, but according to the device are divided into rack, screw and hydraulic. The latter variety is considered the most popular and more famous than the classic rolling.
Such devices are suitable for both a private motorist and tire shops. However, for the operation of the equipment, it is necessary to provide an even hard coating, which is required for movement. In appearance, these types of car jacks are a trolley that moves with the help of wheels made of steel. The design weighs quite a lot, and the price is quite high. Such jacks are not suitable for transportation in a car. This is due to the fact that in the conditions of the road you will not be able to use the device, however, workshops sometimes can not do without such equipment.
The height of the rolling mechanisms is not so high, but stable, the last quality is provided by the platform, which acts as a support. The design includes a lifting device, a pump and a piston. All this allows the equipment to work with a cargo with impressive weight. Using it, you can lift the car to replace wheels. The device also has a shut-off valve, the main role of which is to fix the load at any height. On sale, you can find mechanisms with additional grips that expand the capabilities of the jack. Experts advise to be able to distinguish pseudo-hydraulic models from rolling hydraulic equipment.
Features of the use of rolling devices
If, having considered all types of jacks for cars, you have chosen rolling equipment, then you should familiarize yourself with the features and rules of its use. If there is a need to raise the part of the car where the wheel is located, then the device must first be installed on a flat surface, otherwise unpleasant consequences cannot be avoided. If the mechanism moves, the car will break, and such a violation of the rules will lead to injuries.
You can ask before starting work on what load the device is designed for. If the load norm is exceeded, then the mechanism, like the car, may be damaged. For servicing and repairing a car, you can choose a mechanism with a carrying capacity of 2 tons or less. If we are talking about more powerful transport, then rolling equipment of 5 tons will be required.
A vehicle intended for maintenance needs to be fixed. For wheels in this case, locking shoes are used. This fixation will prevent the body from moving. Mechanisms will only allow you to lift the car, but while the car is installed on them, repair or other work cannot be carried out. As soon as the transport can be raised to the desired height, the mechanisms should be removed, for this, safety stands are used.
Conclusion
Before purchasing this or that type of jack, you need to find out about the mass of your car. This will eliminate the possibility of acquiring a device with the wrong carrying capacity. This parameter should be selected with a small margin.
It must be remembered that powerful mechanisms have more impressive dimensions and mass, so for their transportation and storage you will need a certain amount of free space. Recently, experts have been increasingly recommending the purchase of domestic goods, because, compared to foreign ones, they do not differ much in functionality, but they cost much less. And it will be quite difficult to find service centers for imported devices in your city if you do not live in a megalopolis. As practice shows, domestic jacks are more maintainable, you can fix the problem when it occurs yourself, without resorting to outside help.