Abstract: A gas filter system including an outer filter element having a first filter medium arranged between a first end cap and a second end cap, and an inner filter element having a second filter medium arranged between a third end cap and a fourth end cap, wherein the first filter medium is arrangeable to surround the second filter medium, wherein the first, third and fourth end caps are open, wherein the outer filter element is closed at the second end cap, wherein the outer filter element has an axial protrusion at the second end cap that protrudes into the inner filter element and exhibits a radially outward facing sealing surface, and wherein the fourth end cap of the inner filter element has a second sealing section for sealing abutment against the sealing surface of the protrusion.

Abstract: A gas filter system comprising an outer filter element having a first filter medium arranged between a first end cap and a second end cap, and an inner filter element having a second filter medium arranged between a third end cap and a fourth end cap, the first filter medium being arrangeable to surround the inner filter medium, wherein the first, second, third and fourth end caps are open.

Abstract: A gas filter system including a housing with a sealing projection and a housing groove; an outer filter element having a first filter medium with a first end cap and a second end cap; and an inner filter element having a second filter medium with a third end cap and a fourth end cap, wherein the first end cap has a first axial end cap projection and the third end cap has a second axial end cap projection, the end cap projections being arranged in the housing groove; the first and second end cap projections forming a common groove into which the sealing projection protrudes for sealing abutment against the first end cap and the third end cap at the common groove. The use of an outer filter element and/or an inner filter element in the gas filter system.

Abstract: A gas filter system including an outer filter element having a first filter medium arranged between a first end cap and a second end cap, and an inner filter element having a second filter medium arranged between a third end cap and a fourth end cap, wherein the first, second and third end caps are open, the inner filter element is closed at the fourth end cap, the first filter medium is arrangeable to surround the second filter medium, such that the first end cap of the outer filter element surrounds the third end cap of the inner filter element, the first and third end caps are sealed against each other, and such that the second end cap of the outer filter element surrounds the fourth end cap of the inner filter element, and the second and fourth end caps are sealed against each other.

Abstract: A gas filter system including an outer filter element having a first filter medium arranged between a first end cap and a second end cap, and an inner filter element having a second filter medium arranged between a third end cap and a fourth end cap, wherein the first, third and fourth end caps are open, wherein the outer filter element is closed at the second end cap, wherein the first filter medium is arrangeable to surround the second filter medium, such that the outer filter element is sealed against the inner filter element between the second end cap and the fourth end cap.

Abstract: An air filter element for an air filter for an internal combustion engine is provided with a filter medium surrounding annularly a longitudinal axis of the air filter element. A first end disk is provided at a first end face of the air filter element, wherein the filter medium is embedded in the first end disk at the first end face. A clean air seal is configured to seal a raw side of the air filter against a clean side of the air filter. The clean air seal and the first end disk are embodied together as one piece. The clean air seal protrudes continuously radially past the filter medium. A filter housing for the air filter element is provided with a filter pot and a cover and has a clean air outlet and a raw air inlet arranged at a side wall of the filter pot.

Abstract: A filter system and a filter element of the filter system having a recess arranged on an outside of the filter element and at least one coding element arranged on a circumference of an end cap of the filter element. At least one coding pin is arranged on an inside of a bottom housing part for cooperating with the recess when the filter element is inserted in the housing. The bottom housing part includes a circular shield having a slot extending in the axial direction, wherein the slot is configured to receive the coding element of the filter element when the filter element is inserted in the housing.

Abstract: A casting shell for producing a filter element with a filter body and a seal or end disk has a receiving shell with a groove and a support surface. The groove receives casting material. The support surface supports the filter body during casting. A cover is provided with at least two cover parts arranged so as to be movable separately from each other relative to the receiving shell. The cover parts open the groove in a first position and in a second position, with the filter body inserted as intended in the casting shell, cover the groove. A bottom side of the cover parts faces in the second position a cavity formed by the groove. The bottom side molds a seal or function surface of the seal or end disk. A casting device is provided with such a casting shell. A method using such a casting shell is provided.

Abstract: A filter element for filtering a fluid has a filter bellows arranged about the longitudinal axis of the filter element and enclosing an interior of the filter element. A first end disk open toward the interior is arranged at a first end of the filter element. A second closed end disk is arranged at a second end of the filter element. The second end is oppositely positioned to the first end in a direction of the longitudinal axis. The filter bellows has folds with radially outer fold edges positioned on an outer circumferential surface of the filter bellows. The filter bellows is provided with a notch at least at one of the first and second ends. The notch has an axial length in the direction of the longitudinal axis. The axial length is shorter than a length extension of the filter bellows in the direction of the longitudinal axis.

Abstract: A filter system (100) having a housing (110), a fluid inlet (102) formed in a housing wall (112), a fluid outlet (108) formed in a housing wall (120), a primary filter element (50) and a secondary filter element (10). The secondary filter element (10) is arranged on a stand pipe (150) rigidly connected to one of the housing walls (120). The secondary filter element (10) includes a filter medium (16) forming a body (36) having at least one longitudinal seam (18) along a longitudinal axis (L) and an end cap (20) at its top region (12). The secondary filter element (10) and the stand pipe (150) are mutually connected by connection elements (22, 156). The secondary filter element (10) and the stand pipe (150) are configured with mutual self-positioning elements (30, 180) to arrange the secondary filter element (10) in a defined rotational position with respect to one or more struts (170).

Abstract: A filter element for filtering a fluid has a filter bellows arranged about the longitudinal axis of the filter element and enclosing an interior of the filter element. A first end disk open toward the interior is arranged at a first end of the filter element. A second closed end disk is arranged at a second end of the filter element. The second end is oppositely positioned to the first end in a direction of the longitudinal axis. The filter bellows has folds with radially outer fold edges positioned on an outer circumferential surface of the filter bellows. The filter bellows is provided with a notch at least at one of the first and second ends. The notch has an axial length in the direction of the longitudinal axis. The axial length is shorter than a length extension of the filter bellows in the direction of the longitudinal axis.

Abstract: A filter element for a filter system for filtering a fluid has a filter bellows arranged about a longitudinal axis and enclosing an interior of the filter element. A closed end disk is arranged at a first end of the filter element and closes off the interior of the filter element. An end disk with an opening to the interior of the filter element is arranged at a second end of the filter element oppositely positioned to the first end viewed in direction of the longitudinal axis. The closed end disk has a hollow pin projecting into the interior of the filter element in direction of the longitudinal axis. The filter system has a housing for receiving the exchangeable filter element with a housing part closable by a cover. The hollow pin of the closed end disk can be pushed onto a pin of the housing part.

Abstract: A filter element for a filter system for filtering a fluid has a filter bellows arranged about a longitudinal axis and enclosing an interior of the filter element. An end disk that is provided with an opening to the interior of the filter element is arranged at the filter bellows. The end disk has a bead that is arranged at the opening to the interior and partially surrounds the opening to the interior. The bead projects outwardly in a direction of the longitudinal axis. The filter system has a housing with a cover and a housing part closable by the cover. The filter element can be exchangeably arranged in the housing. The bead, in a mounted state of the filter element in the housing, engages a complementary receptacle arranged at an inner side of the cover.

Abstract: A filter element has a filter bellows of filter medium laid into folds. The folds extend between oppositely positioned end edges of the filter bellows, respectively. The end edges form oppositely positioned end edge surfaces. The filter bellows is arranged in closed configuration about a longitudinal axis and encloses a hollow space. The filter bellows has opposed end faces sealed by an end disc. The filter bellows has a cut portion in at least one of the oppositely positioned end edge surfaces such that one or more regions of folds with shortened fold length are formed. A fold length of the folds with shortened fold length is substantially identical at an outer and inner circumference of the filter bellows. A filter system has a housing in which the filter element is arranged. One of the housing parts has a region corresponding to the cut portion of the filter bellows.

Abstract: A round filter element has a filter medium body flowed through by a fluid to be purified in radial direction relative to a longitudinal axis of the filter medium body. The filter medium body radially encloses an inwardly positioned flow space. An end disk is arranged at an end face of the filter medium body. The end disk has a shaped body axially delimiting the inwardly positioned flow space. The end disk has a sealing disk arranged externally at the shaped body, wherein the sealing disk covers the shaped body and the end face of the filter medium body. The shaped body has a receiving depression that is flow-tight relative to the inwardly positioned flow space. The sealing disk has a receiving opening aligned with the receiving depression of the shaped body. The receiving depression and the receiving opening can receive a support element of a filter housing.

Abstract: A secondary element for a filter system has first and second ends oppositely positioned to each other in longitudinal direction. The first end is closed by a closed end disk. The closed end disk has a first connection device for interacting with a complementary second connection device of a central tube of the filter system and for fixing the secondary element on the central tube. The first connection device has lock elements with radially inwardly oriented lock hooks distributed circumferentially on the closed end disk. A filter medium surrounds the lock elements. The lock elements include two directly neighboring lock elements having a distance relative to each other along the circumference of the closed end disk that is larger than a circumferential measurement of a radially outwardly oriented deflection element arranged at a collar of the central tube. A filter system with such a secondary element is provided.

Abstract: A cover for a filter system for filtering a fluid has a fluid channel arranged at an inner side of the cover. The cover has a rim and at least one opening arranged in the rim to allow the fluid to pass through, wherein the opening is connected in fluid communication with the fluid channel. The fluid channel is connected in fluid communication with the interior of a filter element of the filter system. A seal for the cover has a first sealing ring and a second sealing connected to each other by flanks. The filter system has a housing with a housing part that is closable by the cover. A filter element is exchangeably arranged in the housing, and the fluid channel of the cover is connected in fluid communication to the interior of the filter element.

Abstract: A filter element has a filter medium body with a first side and an oppositely positioned second side, wherein one of the first and second sides is the inflow side of the filter medium body and the other one is the outflow side of the filter medium body. A first sealing or supporting element is arranged at the first side. A second sealing or supporting element is arranged at the second side. At least one force-transmitting adhesive bead extends between the first side and the second side, wherein the at least one adhesive bead is a force transmitting element extending between the first and second sealing or supporting elements.

Abstract: A round filter element has a filter medium body with a wall to be flowed through by a fluid to be purified in a radial direction relative to a longitudinal axis of the filter medium body. A circumferentially extending seal carrier is arranged at or adjacent to an end face of the filter medium body. A sealing element is supported at the seal carrier adjacent to a radial outer side of the filter medium body. A positioning element extends into the filter medium body and engages with a correlated housing-associated counter positioning element of a filter housing when the round filter element is installed in the filter housing. The seal carrier separates flow-tightly a raw side of the round filter element from a clean side of the round filter element when the round filter element is installed in the filter housing.

Abstract: A filter element for filtering a fluid has a support pipe and a filter bellows arranged about a longitudinal axis on the support pipe. The filter bellows has folds with radially outer fold edges. The filter bellows has a first axial end and a second oppositely positioned axial end. The filter bellows has a notch at least at one of the first and second axial ends. An axial length of the notch in longitudinal direction is shorter than a longitudinal extension of the filter bellows. The support pipe has a support structure at the axial end with the notch and has at least two wings. The support structure is oriented radially away from the support pipe and is integrated into the end disk at both sides of the notch. A filter system with such a filter element arranged in a housing is provided.