How does the device work?
The rolling jack is somewhat reminiscent of a four-wheel trolley, which must be brought under a pallet with a load. At the same time, the horizontal rod extends and starts the mechanism for vertical lifting of the thrust platform. Such a mechanism, as a rule, is articulated, and everything else (rolling of the device, lifting the load) is carried out only with the help of the handle.
After the device has rolled up to the machine, the handle is turned and thereby the inlet valve of the container is opened. A retractable piston is located in this container. Next, the handle begins to wiggle and this activates the pump, pumping the liquid and starting the hinge mechanism. All further major work falls on the straight inlet valve and plunger.
When lowering a weight or if you need to reduce the pressure in the system, simply turn the control knob to the other side. Then the outlet valve opens and the liquid under the piston begins to flow into the reserve tank.
Thus, all the work of such a jack is carried out due to the overflow of liquid in interconnected vessels and an increase in power when the area of the expended efforts changes.
Choice
Jack pads are small rounded products designed for installation on the upper support of a rolling tool. Regardless of the types of attachments, they all perform the same function. It consists in reliable protection of the car from mechanical damage. To choose the optimal type of support, you need to heed a number of recommendations.
The accessory should be selected in accordance with the type of jack, otherwise the product will simply be useless
Even if the washer is universal, you need to pay attention to the size of the metal bowl.
The material from which the spacer is made must be strong but elastic. A product that is too rigid will quickly become unusable - at the very first loads it can crack or completely collapse.
Washer should not be thin
The minimum height of the product is 3.5 cm. At lower values, there are great risks of "cutting" the rubber to metal under the influence of loads.
Domestic and foreign linings are presented on the market. Here are a few companies that have managed to earn the consumer's trust by producing high-quality and reliable, but at the same time inexpensive accessories. These include the following manufacturers: Ombra, Matrix, Ermak, Kraft, Zubr. The linings of these brands are resistant to high and low temperatures, temperature extremes, and various negative atmospheric influences. They quickly regain their former shape after unloading and change their geometry minimally after prolonged compression. Such accessories will last a long time and will not let you down at a crucial moment.
Device and principle of operation
Rolling jack scheme
The trolley hydraulic jack is a trolley on wheels. This type is very convenient in operation, it has a large lifting capacity and smooth lifting. The hydraulic drive is at the heart of the operating principle.
To raise the car to the required height, roll up the jack under it, place the bearing stop at the point of the car body intended for lifting. There are special places on the body of the car where you need to rest the jack. The next step is to swing the handle up and down, the bearing stop should begin to rise, and with it the car.
The main design element is hydraulic cylinders, pumping the handle, a certain pressure is created in the cylinders, due to which the lifting is carried out. The main work, lifting, is performed by the plunger and the straight valve. By turning the handle of the check valve, the pressure in the system will decrease, as a result of which the car will lower to its original position. In different models, the handle is located in different places, read the instructions for the rolling jack, everything is clearly stated there.
How to use PD
Wheel chock
When using a rolling jack, it is imperative to observe the safety rules. In particular, the vehicle must be on a level surface so that it does not fall to the ground during lifting and when suspended. If it is not possible to place the car on a flat surface, then it is imperative to place stops under the wheels (chocks, bricks or other bulky and heavy objects).
The operating procedure is very simple. Roller jacks have rollers, with the help of which the structure must be placed under the place where the rod rests.
Remember that each machine has several dedicated locations for jack use. Do not place the jack in other places, as this can damage the geometry of the car body.
Most jacks have a drive handle (and some have a pedal) that must be moved up and down to move the operating mechanism. Accordingly, the body of the machine begins to rise. To lower the car, a special lever or button is provided in the jack structure (depending on the specific model). In this case, the working fluid returns through the open shut-off valve into the working cavity. This will cause the stem to return to its original position and the machine to lower.
Do not use a jack to lift vehicles that are heavier than the vehicle's weight. This can lead, firstly, to its failure (deformation of the stem, rupture of the sealing rings), and secondly, to the threat that the jack will not withstand the load and the machine may fall.
That is, if a rolling jack is designed for 3 tons, then you do not need to try to lift a car weighing 3.5 or more with it. Although hoists usually have a margin of safety, they are only designed for short-term use. Also, if the car is supposed to be kept in a suspended state for a long time, then the jack must be replaced with a permanent support.
Outcomes
The hydraulic trolley jack is an excellent tool used in car services and garages of ordinary people. Its design is very convenient and efficient. Remember that the jack is a lifting tool, not a holding tool. With long-term work, it is worth taking care of a reliable support.
When choosing a jack, pay attention to the lifting capacity, the minimum (necessarily less than the vehicle's ground clearance) and maximum lifting height. After the criteria are determined, we recommend buying a jack in the middle price category for individuals, and car services are advised to pay attention to a professional tool
