Hydraulic damper with piston assembly having blow-off valves

A hydraulic damper (1), comprising:

• a tube (3) filled with working liquid;
• a piston assembly (4) disposed slidably inside the tube (3), dividing the tube (3) into a rebound chamber (11) and a compression chamber (12), the piston assembly including two sleeve-shaped members (44), a rebound valve assembly (41r, 42r), and a compression valve assembly (41c, 42c), wherein each of the rebound valve assembly (41r, 42r) and the compression valve assembly (41c, 42c) includes a deflectable-disc valve (41) and a blow-off valve (42);
• an internal chamber (43) extending between the two sleeve-shaped members (44);
• a piston rod (5) attached to the piston assembly (4) and extending outside the tube (3) through a sealed piston rod guide (6);
• wherein each of the sleeve-shaped members (44) defines a plurality of blow-off valve flow passages (442), which are radially proximal, a plurality of deflectable-disc valve flow passages (441), which are radially distal, and a central opening (443),
• wherein the piston rod (5) passes through said central openings (443) in each of said sleeve-shaped members (44);
• each of the deflectable-disc valves (41) including at least one deflectable disc (411) covering an external end of said deflectable-disc valve flow passages (441) of a corresponding one of said sleeve-shaped members (44);
• wherein each of said at least one deflectable disc (411) is axially fixed at said piston rod and defines a plurality of radially proximal flow passages (4111) corresponding to said blow-off valve flow passages (442) of a corresponding one of said sleeve-shaped members (44);
• each of the blow-off valves (42) including at least one disc (422, 423) adjoining an internal end of said blow-off valve flow passages (442) of a corresponding one of said sleeve-shaped members (44);
• wherein a flow channel (4221, 426) fluidly connects said internal chamber (43) with said blow-off valve flow passages (442) of each sleeve-shaped members (44);
• and
• wherein the piston assembly (4) further comprises a spring seat (425) abutting said at least one disc (422, 423) of each of the blow-off valves (42), and at least one spring (47) disposed within said internal chamber (43) and configured to bias said spring seats (425) towards said at least one disc (422, 423).