Filtering device for damping vibrations in a conduit of a hydraulic actuation system for disengaging a clutch

A filtering device for damping vibrations in a conduit between a master cylinder and a slave cylinder of a hydraulic actuation system for disengaging a clutch, the filtering device comprising:

• an outer body comprising a through cavity extending longitudinally between two opposite ends, the through cavity having:
• a first passage section to be placed, in use, towards the slave cylinder,
• an intermediate chamber,
• a second passage section to be placed, in use, towards the master cylinder, and
• a radial shoulder between the intermediate chamber and the first passage section;
• a valve mechanism comprising a first valve element and a second valve element mounted telescopically floating in the intermediate chamber, and a spring axially compressed between the first and second valve elements,
• wherein the first valve element is a cup-shaped element mounted in the intermediate chamber in a radially outermost position and comprises an axially extended tubular portion, a transversal base arranged towards a side of the slave cylinder and capable of coming into abutment against the radial shoulder, and a substantially central through opening formed in the transversal base;
• wherein:
• the second valve element is a cup-shaped element comprising:
• a tubular portion mounted coaxially inside the axially extended tubular portion of the first valve element,
• a transversal base, arranged towards the master cylinder side of the filtering device,
• at least one longitudinal through hole formed through the transversal base, and
• an appendage longitudinally protruding from the transversal base towards the master cylinder side;
• a plug is fixed in the through cavity between the intermediate chamber and the second passage section, the plug forming:
• a longitudinally extending through seat that longitudinally accommodates the appendage of the second valve element,
• a transversal surface constituting a stop for the transversal base of the second valve element, and
• at least one outer longitudinal passage establishing a fluid communication between the intermediate chamber and the second passage section,
• and at least one outer passage extends longitudinally outside the axially extended tubular portion between two opposite longitudinal ends of the axially extended tubular portion.