Pointed jack

A pointed jack is a light and small lifting equipment that uses a steel lifting component as a working device to lift heavy objects within its stroke through a top support seat or bottom support claw. According to structural characteristics, it can be divided into three types: rack jack, screw jack, and hydraulic jack. Jack is a simple lifting equipment with a small lifting height (less than 1m). It has two types: mechanical and hydraulic. There are two types of mechanical jacks: rack and screw jacks. Due to their small lifting capacity and laborious operation, they are generally only used for mechanical maintenance work and are not suitable for bridge repair. Hydraulic jacks have a compact structure, smooth operation, and self-locking function, making them widely used. Its disadvantages are limited lifting height and slow lifting speed.

Pointed jacks are divided into two types: mechanical jacks and hydraulic jacks, each with different principles. In principle, the hydraulic jack is based on the Pascal principle, which means that the pressure of the liquid is consistent everywhere. In a balanced system, the pressure applied on the smaller piston is relatively small, while the pressure applied on the larger piston is also relatively large, which can maintain the liquid at rest.