HAND PISTON PUMP Russian patent published in 1994 - IPC

FIELD: manufacture of hydraulic drives. SUBSTANCE: mounted on rod for axial displacement are piston and mechanism of coupling the piston with rod. Piston is made in form of sleeve and coupling mechanism is made in form of stops mounted on rod on either side from sleeve bottom and engageable with them. Compression spring is mounted in sleeve chamber between bottom and stop of rod. Stroke of piston between stops is lesser than stroke of rod in cylinder. Additional piston with spring embraces piston located inside it. Each piston being embraced is provided with stops engageable with embracing piston. EFFECT: enhanced reliability. 2 cl, 2 dwg