A frameless lightweight jack may include a pressure cylinder, the pressure cylinder having a pressure cylinder passage and a pressure cylinder body including a body passage, the pressure cylinder body mechanically coupled to the pressure cylinder. A first and a second hydraulic actuator may be coupled to the pressure cylinder body on a proximal end, the actuators are in hydraulic communication through a cylinder loop hose connected to each hydraulic actuator. An extending body may be coupled to the hydraulic actuators, and may include an extending body passage, wherein the pressure cylinder passage, the pressure cylinder body passage, and the extending body passage are aligned to form a tension member channel. A strand grabber assembly may be mechanically coupled to the extending body, wherein the pressure cylinder, pressure cylinder body, and extending body are comprised of aluminum, titanium, fiber reinforced plastic, polymers, or carbon fiber.

An electric hydraulic floor jack includes a variable plunger structure provided on a motor base and an oil pump base. The variable plunger structure includes a piston hole formed in the oil pump base and communicating with an oil chamber and an oil inlet passage, a plunger sleeve provided at a port of the piston hole, a plunger slidably provided in the plunger sleeve, a U-shaped piston slidably provided in the piston hole, a valve trim slidably provided on the piston, a spring provided in the piston hole and sleeved on the valve trim, and an eccentric wheel provided on an output shaft of a speed reducer. The plunger is driven by the eccentric wheel in cooperation with the spring to continuously make a linear reciprocating motion, thereby continuously opening and closing the check valve, and pumping oil into the cylinder to push the piston rod for lifting work.