Hydraulic jack

A hydraulic jack, comprising:

• a hydraulic cylinder storing hydraulic fluid inside, the hydraulic cylinder including a cylindrical body and a top portion, wherein the top portion includes a fastening part;
• a piston installed in the hydraulic cylinder that is raised up from the hydraulic cylinder by a pressure of the hydraulic fluid stored in the hydraulic cylinder, wherein the piston is used to lift up a heavyweight, and wherein the piston has at least one drill hole on a body thereof, the drill hole has a determined diameter and is perpendicular to the piston;
• a security piece that is attachable to the top portion of the hydraulic cylinder by means of the fastening part, the security piece including a longitudinal central opening, of which a size is larger than the diameter of the piston so that the security piece can pass through the piston from top to bottom to contact with the top portion of the hydraulic cylinder, wherein the security piece has a height large enough so that the security piece surrounds a lower portion of the piston;
• and
• a safety pin for inserting into one of the at least one drill hole of the piston when the piston is raised up to secure the piston in place,
• wherein the fastening part of the top portion comprises a first magnet, and a bottom of the security piece comprises a second magnet, and wherein the first magnet and the second magnet attract to each other when the security piece attaches to the top portion of the hydraulic cylinder.

A hydraulic jack, comprising:

• a hydraulic cylinder storing hydraulic fluid inside, the hydraulic cylinder including a cylindrical body and a top portion, wherein the top portion includes a receiving device on a top surface thereof;
• a piston installed in the hydraulic cylinder that is raised up from the hydraulic cylinder by a pressure of the hydraulic fluid stored in the hydraulic cylinder, wherein the piston is used to lift up a heavyweight, and wherein the piston has at least one drill hole on a body thereof, the at least one drill hole has a determined diameter and is perpendicular to the piston;
• a security piece that is attachable to the top portion of the hydraulic cylinder by means of a receiving device, the security piece including a longitudinal opening of which a size larger than the diameter of the piston so that the security piece can pass through the piston from top to bottom to be placed in the receiving device of the top portion of the hydraulic cylinder, wherein the security piece has a height large enough so that the security piece surrounds a lower portion of the piston;
• and
• a safety pin that inserts to one of the at least one drill hole of the piston when the piston is raised up to secure the piston in place,
• wherein the receiving device is a circular recess located on the top portion of the hydraulic cylinder, of which the circumferential dimension is substantially the same as a bottom circumferential dimension of the security piece, and
• wherein the security piece is placed in the circuit recess of the top portion of the hydraulic cylinder.

A hydraulic jack, comprising:

• a hydraulic cylinder storing hydraulic fluid inside, the hydraulic cylinder including a cylindrical body and a top portion, wherein the top portion includes a fastening part;
• a piston installed in the hydraulic cylinder that is raised up from the hydraulic cylinder by a pressure of the hydraulic fluid stored in the hydraulic cylinder, wherein the piston is used to lift up a heavyweight, and wherein the piston has at least one drill hole on a body thereof, the at least one drill hole has a determined diameter and is perpendicular to the piston;
• a security piece that is attachable to the top portion of the hydraulic cylinder, the security piece including a longitudinal opening of which a size larger than the diameter of the piston so that the security piece can pass through the piston from top to bottom to contact with the top portion of the hydraulic cylinder, wherein the security piece has a height large enough so that the security piece surrounds a lower portion of the piston, wherein the security piece comprises a pair of through holes on an outer wall thereof in opposite positions, and the pair of through holes are aligned with the at least one drill hole of the piston, wherein an upper end of an external wall of the top portion of the hydraulic cylinder comprises at least one recess and a lower portion of an inner wall of the security piece comprises at least one protrusion, wherein the at least one protrusion and the at least one recess engage together when the security piece is attached to the top portion of the hydraulic cylinder, and
• a safety pin that inserts to in an order of one of the pair of through holes of the security piece, one of the at least one drill hole of the piston, and the other one of the pair of through holes of the security piece when the piston is raised up to secure the piston in place.