Patent ID: 7779745
Filing Date: 2010-08-24
Classification: F15B

Abstract:
1. Automatic-locking hydraulic jack comprising a piston ( 1 , 30 ) that slides into a cylinder ( 3 - 2 , 32 ), in which the locking of the piston is achieved by elastic deformation of the outside wall of the piston ( 30 ) so as to ensure that the piston is tightly clamped within the cylinder, characterized by the fact that the locking of the jack is achieved by means of pressure that causes the elastic deformation of the outside wall of the piston ( 30 ), whereby the unlocking of said jack is achieved by neutralizing this deformation, wherein the piston ( 30 ) comprises an airtight chamber that is permanently filled with a compressed neutral gas that effects said elastic deformation, and wherein unlocking is achieved by a hydraulic pressure that intervenes between the piston ( 1 , 30 ) and the cylinder ( 3 - 2 , 32 ) and exerts an antagonistic counter-pressure that neutralizes the elastic deformation that is caused by the compressed neutral gas.