Pressure cartridge

A cartridge assembly comprising a housing having a single chamber for containing hydraulic fluid, an intensifier element capable of reciprocating in the chamber and displacing the hydraulic fluid responsive to a drive means acting on the intensifier element, and a piston capable of reciprocating in the chamber and being displaceable responsive to a change in pressure of the hydraulic fluid;

• the cartridge assembly configured so that when the pressure in the fluid increases responsive to a first force being applied by the drive means on the intensifier, the hydraulic fluid will exert a second force on the piston, the second force being greater than the first force;
• a mass of the hydraulic fluid being conserved within the chamber, the drive means comprising a servomotor coupled to a threaded beam having a longitudinal axis, a position of the threaded beam relative to the housing being fixed, the servomotor and the beam arranged such that rotation of the beam about its longitudinal axis can be selectively driven by the servomotor, the intensifier element being driveably coupled to the threaded beam by means of a cooperatively threaded mechanism, such that rotation of the beam will result in a longitudinal force being applied to the intensifier element via the threaded mechanism.