The screw jack, also referred to as the mechanical jack, is driven by a manpower through a screw pair, and a screw or nut sleeve is 
used as a jacking member. The normal screw jack supports the pounds by the thread self-locking function, and the framework is simple, but the transmission efficiency can be low and the return stroke is gradual. The thread of the self-propelled screw jack has no self-locking action and has a brake. When the brake is normally released, the weight can be quickly lowered by itself and the return time can be shortened, however the framework of the jack is certainly complicated. The screw jack can support heavy items for a long period, and the utmost lifting capacity has reached 100 tons, which is trusted. After the horizontal screw can be Greenhouse Reducer mounted on the lower part, the weight could be traversed at a little distance.
Principle useful:
The mechanical jack is among the types of manual lifting tools. Its compact structure makes reasonable utilization of the rocking of the rocker to rotate the pinion. It is operated by a set of conical gears to operate a vehicle the screw to rotate and press the lifting sleeve so that the fat rises or decline.
Instructions:
1. Before use, it’s important to check if the jack is normal, whether the elements are flexible, increase lubricating oil, and properly estimate the excess weight of the large object. Use a jack of appropriate tonnage and steer clear of overloading.
2. Adjust the method of supporting one’s teeth on the rocker. Firstly, turn the rocker straight in the clockwise direction by hand to help make the lifting sleeve quickly ascend the very best weight.
3. Insert the handle in to the rocker hole, move the handle along, and the excess weight will rise. When the crimson warning line appears on the lifting sleeve, the handle should be stopped immediately. If you want to lower one’s teeth in the contrary direction, the excess weight will start to fall.
Precautions:
1. Constantly keep the top of machine clean, examine the internal structure regularly, make the pinion in the rocker flexible and dependable, and lift the lifting sleeve freely.
2. The friction surface between your lifting sleeve and the housing must be oiled at any time. Other essential oil filling holes should be lubricated regularly.
3. In order to consider the safety in use, avoid overloading, use illness, it isn’t appropriate to make use of multiple units to avoid danger.