Patent ID: 11931675
Assignee: VOLVO TRUCK CORPORATION
Field: Chemical engineering (Chemistry)
Classification: CPC B | IPC B

Claim 32:
33. A filter element comprising:
a filter medium configured with an annular shape, having a central axis and forming inside a central channel extending substantially axially;
first and second end plates, each plate covering and being sealingly mounted on one axial end of the filter medium, the first end plate having a central opening substantially coaxial with the central axis and in fluid communication with the channel;
a central perforated rigid tube that extends axially between the first and second end plates and having an inner perforated wall delimiting the central channel the filter element being designed to be placed in a filter housing for forming a liquid filtering device, whereby a liquid to be filtered can flow along a liquid path through the filter medium towards the channel and out of the filter element through the central opening,
wherein:
the central perforated rigid tube comprises at least one guiding path, arranged inside the central perforated rigid tube, adapted to generate, by contact with a following member of a rotatable central element of the filter housing, at least a first, progressive rotational movement of the rotatable element of the filter housing when the filter element is mounted in the filter housing during a first translation movement along the central axis:
said at least one guiding path comprises at least one portion of a helical path for obtaining the first, progressive rotational movement, and the helical path extends on less than half of the inner periphery of the central perforated rigid tube in order to generate a rotation of the rotatable element inferior to one half of a turn
wherein the guiding path is adapted to generate, when the filter element is dismounted from e filter housing during a second translation movement along the central axis in the opposite direction with respect to the first movement, a second rotational movement of the rotatable element, in the opposite direction with respect to the progressive rotational movement, this second rotational movement occurring at the beginning of the second translation movement, wherein the guiding path comprises an insertion section, which comprises the helical path, and a dismounting section, which comprises a portion with an angle of inclination that, when measured with respect to the central axis of the filter element, is greater than the angle of inclination of the helical path of the insertion section.