Off-type jack fittings sheet metal multi-purpose jack pump Manual hydraulic off-type oil pump has the characteristics of compact structure, stable work, high tension and self-locking. The hydraulic jack has strong thrust capacity, and the thrust of the heavy oil hydraulic jack exceeds 1 00t. When the joystick handle is lifted by hand1,the small piston rises, and the working volume of the internal seal in the pump body 2 increases. At this time, since the drain check valve 3 and the drain valve 8 close their respective oil paths, the working volume in the pump body 2 increases, and a partial vacuum is formed. Under the action of atmospheric pressure, the oil in the oil tank opens the oil suction check valve 4 through the oil pipe and flows into the pump body 2 to complete the oil suction action. Universal hydraulic jack is suitable for all kinds of lifting operations with low crane height. It consists of oil chamber, oil pump, oil storage chamber, piston, handle, hydraulic valve and other main components. When moving, as long as the handle moves back and forth to make the manual oil pump always move in the cylinder, the hydraulic pressure in the cylinder will become higher, so the piston and the weight on the piston move upward together. After the reset valve is opened, the high-pressure oil in the oil cylinder returns to the oil storage cavity, and the weight falls with the piston.