The screw jack, also known as the mechanical jack, is driven by a manpower through a screw pair, and a screw or nut sleeve is utilized as a jacking member. The normal screw jack supports the fat by the thread self-locking function, and the framework is simple, however the transmission performance is usually low and the come back stroke is sluggish. The thread of the self-propelled screw jack has no self-locking action and has a brake. When the brake is certainly released, the weight can be quickly lowered alone and the return period can be shortened, but the structure of the jack is certainly complicated. The screw jack can support heavy items for a long time, and the maximum lifting capacity has reached 100 tons, which is widely used. After the horizontal screw is normally mounted on the lower part, the weight could be traversed at a small distance.
Principle useful:
The mechanical jack is one of the types of manual lifting tools. Its compact framework makes reasonable usage of the rocking of the rocker to rotate the pinion. It really is operated by a pair of conical gears to operate a vehicle the screw to rotate and drive the lifting sleeve to V Belt Pulley ensure that the weight rises or decline.
Instructions:
1. Before use, it is necessary to check whether the jack is normal, whether the elements are flexible, 
add lubricating oil, and correctly estimate the weight of the heavy object. Make use of a jack of suitable tonnage and prevent overloading.
2. Adjust the method of supporting the teeth on the rocker. Firstly, turn the rocker straight in the clockwise path by hand to make the lifting sleeve quickly ascend the top weight.
3. Insert the handle in to the rocker hole, move the deal with along, and the weight will rise. When the crimson warning line shows up on the lifting sleeve, the handle should be stopped immediately. If you want to lower one’s teeth in the opposite direction, the fat will start to fall.
Precautions:
1. Generally keep the surface of the machine clean, verify the internal structure regularly, make the pinion in the rocker flexible and reliable, and lift the lifting sleeve openly.
2. The friction surface between the lifting sleeve and the housing must be oiled anytime. Other oil filling holes should be lubricated regularly.
3. In order to consider the safety used, avoid overloading, use illness, it is not appropriate to use multiple units in order to avoid danger.