# US 4,392,584 A · Vent cap for a container accommodating hydraulic fluids > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,392,584 A - Document ID: US4392584A - Status: Granted - Kind: A - Application number: 06/202,413 - Filed: 1980-10-30 - Granted: 1983-07-12 - Earliest claimed: 1979-10-30 - Assignees: Daimler-Benz Aktiengesellschaft - Inventors: Ludwig Bauer - Web page: https://patentgrep.com/patent/US4392584A ## CPC - B65D 51/1611: {by means of an orifice, capillary or labyrinth passage (B65D51/1616, B65D51/1622 take precedence)} - B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES ## Abstract A vent cap for a container of housing which accommodates a hydraulic operating medium. The vent cap includes a housing type cover which has labyrinth walls. The cover is adapted to be closed by a base insert which includes a vent passage. The vent cap is adapted to be mounted on a vent opening of the container or housing. The housing type cover is rotatably mounted on the base insert. ## Claims ### Claim 1 A vent cap for closing and venting an opening of a container for hydraulic operating means located on the ambient-air side, said opening comprising an aperture with edges for connecting the interior of the container with the ambient air, having a lid-shaped part with a peripheral wall and a base-shaped part of the cap, where the base-shaped part of the cap is inserted within the peripheral wall of the lid-shaped part of the cap and has ring-shaped sealing means for the sealing of the opening disposed centrally with respect to a central axis, and where one of the parts of the cap is provided with fastening means for the detachable securing of the fitting position of the vent cap at the opening of the container and both parts of the cap have corresponding central mounting supports for the mutual mounting, with said mounting supports fastening the parts of the cap essentially immovably with respect to one another in the direction of the central axis, characterized in that the lid-shaped part of the cap has a journal located radially on the inside with respect to the central axis, and the base-shaped part of the cap has a hub resting on the journal, with the hub being provided with a central ring-shaped receiving groove contacting said edges which is separated from the fastening means, for said sealing ring means engaging said edges, and both parts of the cap in fitting direction, by means of their journal-hub-mounting, being mounted so that they can be rotated freely with respect to one another. ### Claim 2 (depends on 1) A vent cap according to claim 1, characterized in that the lid-shaped and base-shaped parts include a plurality of labyrinth walls. ### Claim 3 (depends on 2) A vent cap according to claim 2, characterized in that the fluid is a hydraulic operating fluid. ### Claim 4 (depends on 2) A vent cap according to claim 2, characterized in that a plurality of tongues are provided on the base-shaped part on an end thereof opposite the lid-shaped part, means are provided on each of the tongues for axially fixing the vent cap in the vent opening of a container, and in that the tongues are radially compressible with respect to a longitudinally extending axis of the base-shaped part. ### Claim 5 (depends on 4) A vent cap according to claim 4, characterized in that the means for axially fixing the vent cap in the opening includes a barbed tip provided on each of the tongues. ### Claim 6 (depends on 4) A vent cap according to claim 4, characterized in that the tongues are made of a plastic material. ### Claim 7 (depends on 1, 2) A vent cap according to one of claims 1, 2, or 4, characterized in that said seal means includes an annular seal means accommodated in the groove. ### Claim 8 (depends on 7) A vent cap according to claim 7, characterized in that the means for mounting the housing cover on the base insert means includes a bearing pin provided on the housing cover, and a hub provided on the base insert means, and in that the bearing pin is disposed so as to be coaxial with respect to the longitudinal axis of the base insert means. ### Claim 9 (depends on 8) A vent cap according to claim 8, characterized in that the lid-shaped part includes a chamber, and in that the bearing pin includes at least one passageway for communicating the opening means with the chamber thereby enabling a venting of an interior of the container when the cap is installed on the vent opening of the container. ### Claim 10 (depends on 1, 2) A vent cap according to one of claims 1, 2, or 4, characterized in that the means for mounting the lid-shaped part on the base-shaped part includes a bearing pin provided on the lid-shaped part, and a hub provided on the base-shaped part, and in that the bearing pin is disposed so as to be coaxial with respect to a longitudinally extending center axis of the base-shaped part. ### Claim 11 (depends on 10) A vent cap according to claim 10, characterized in that the lid-shaped part includes a chamber, and in that the bearing pin includes at least one passageway for communicating the vent opening means with the chamber thereby enabling a venting of an interior of the container when the vent cap is installed on the opening of the container. ### Claim 12 (depends on 1, 2) A vent cap according to one of claims 1, 2, or 4 characterized in that the base-shaped part includes a plurality of labyrinth walls, and in that means are provided for communicating an interior of the vent cap with the atmosphere when the vent cap is installed on the opening of the container. ### Claim 13 (depends on 1, 2) A vent cap according to one of claims 1, 2, or 4, characterized in that the base-shaped part includes a bead portion, and in that the lid-shaped part includes means for accommodating the bead portion so as to enable an axial mounting of the lid-shaped part on the base-shaped part. ### Claim 14 (depends on 2) A vent cap according to claim 2, characterized in that a vent opening means is disposed eccentrically with respect to a longitudinal center axis of the base-shaped part, means for mounting the lid-shaped part on the base-shaped part includes a threaded nut, means are provided for fixedly mounting the threaded nut to the housing cover, and in that the base-shaped part is provided with a central opening for accommodating the threaded nut. ### Claim 15 (depends on 14) A vent cap according to claim 14, characterized in that the threaded nut is a metal nut. ### Claim 16 (depends on 14) A vent cap according to claim 14, characterized in that means are provided for axially fixing the threaded nut with respect to the lid-shaped part. ### Claim 17 (depends on 16) A vent cap according to claim 16, characterized in that the means for mounting the lid-shaped part on the base-shaped part further includes a bearing pin means provided on the threaded nut at a position disposed opposite the lid-shaped part, and a hub means provided on the base-shaped part, the hub means are adapted to be mounted on the bearing pin. ### Claim 18 (depends on 17) A vent cap according to claim 17, characterized in that the bearing pin includes a free end, and in that an annular bear is provided on the free end of the bearing pin for axially fixing the hub with respect to the threaded nut. ### Claim 19 (depends on 18) A vent cap according to claim 18, characterized in that the hub is made of a plastic material. ### Claim 20 (depends on 17, 18) A vent cap according to one of claims 17, 18, or 19, characterized in that the means for fixedly mounting the threaded nut to the lid-shaped part includes a mounting pin provided on the threaded nut at a position opposite the bearing pin, and in that the lid-shaped part is provided with a recess means for accommodating the mounting pin. ### Claim 21 (depends on 20) A vent cap according to claim 20, characterized in that the lid-shaped part includes a pin-shaped extension, and in that the recess means for accommodating the mounting pin is disposed in the extension. ### Claim 22 (depends on 21) A vent cap according to claim 21, characterized in that the means for fixedly mounting the threaded nut to the lid-shaped part further includes a bead means provided on the threaded nut for non-rotatably mounting the threaded nut in the lid-shaped part. ### Claim 23 (depends on 22) A vent cap according to claim 22, characterized in that the base-shaped part includes an end surface, the threaded nut includes an end surface disposed opposite the lid-shaped part, and in that the end surface of the base-shaped part is disposed at a distance from an end surface of the lid-shaped part which is less than a distance of the end surface of the threaded nut from the end surface of the lid-shaped part, as viewed in a direction of the longitudinal center axis of the base-shaped part. ### Claim 24 (depends on 23) A vent cap according to claim 23, characterized in that an annular groove means is provided in the end surface of the base-shaped part concentric to the longitudinal center axis of the base-shaped part, and in that an annular seal is disposed in the annular groove means. ### Claim 25 (depends on 14, 16, 17) A vent cap according to one of claims 14, 16, 17, or 18, characterized in that the base-shaped part includes an end surface, the threaded nut includes an end surface disposed opposite the lid-shaped part, and in that the end surface of the base-shaped part is disposed at a distance from an end surface of the lid-shaped part which is less than a distance of the end surface of the threaded nut from the end surface of the lid-shaped part, as viewed in a direction of the longitudinal center axis of the base-shaped part. ### Claim 26 (depends on 25) A vent cap according to claim 25, characterized in that an annular groove means is provided in the end surface of the base-shaped part concentric to the longitudinal center axis of the base insert means, and in that an annular seal is disposed in the annular groove means. ### Claim 27 A vent cap adapted to be mounted on the vent opening of a container for accommodating a fluid, the vent cap including a housing cover, a base insert means for covering the housing cover, and a vent opening means, characterized in that means are provided for rotatably mounting the housing cover on the base insert means including a bearing pin provided on the housing cover, and a hub provided on the base insert means, the base insert means includes a circumferential groove means located outside of the housing cover, an annular seal means is accommodated in the circumferential groove means, the bearing pin is disposed so as to be coaxial with respect to a longitudinal axis of the base insert means, the cover housing includes a chamber, the bearing pin includes at least one passageway for communicating the vent opening with the chamber, the bearing pin further includes a plurality of tongues adapted to be radially compressible with respect to the longitudinal axis of the base insert means under a spring tension, and in that the hub includes stop means cooperable with tongues of the bearing pin for axially fixing the housing cover relative to the base insert means. ### Claim 28 (depends on 27) A vent cap according to claim 27, characterized in that each of the tongues includes tip portions at free ends thereof adapted to engage the stop means of the hub. ### Claim 29 (depends on 27) A vent cap according to claim 27, characterized in that the base insert means further includes a plurality of labyrinth walls, and in that means are provided for communicating a chamber of the vent cap with the atmosphere when the vent cap is installed on the vent opening of the container. ### Claim 30 (depends on 29) A vent cap according to claim 29, characterized in that said means for communicating the chamber with the atmosphere is an annular slot formed between an edge of the housing cover and one of the labyrinth walls of the base insert means. ### Claim 31 (depends on 30) A vent cap according to claim 30, characterized in that the hub further includes an inner bead portion, the bearing pin further includes an annular groove means for accommodating the inner bead portion so as to enable an axial mounting of the hub on the bearing pin. ### Claim 32 A vent cap adapted to be mounted on a vent opening of a container for accommodating a fluid, the vent cap including a housing cover, a base insert means for covering the housing cover, and a vent opening means, characterized in that means are provided for rotatably mounting the housing cover on the base insert means including a bearing pin provided on the housing cover, and a hub provided on the base insert means, the bearing pin is disposed so as to be coaxial with respect to a longitudinally extending center axis of the base insert means, the cover housing includes a chamber, the bearin pin includes at least one passageway for communicating the vent opening means with the chamber, the bearing pin further includes a plurality of tongues adapted to be radially compressible with respect to the longitudinally extending center axis of the base insert means under a spring tension, and in that the hub includes stop means cooperable with tongues of the bearing pin for axially fixing the housing cover relative to the base insert means. ### Claim 33 A vent cap adapted to be mounted on a vent opening of a container for accommodating a fluid, the vent cap comprising a housing cover, a base insert means for covering the housing cover, and a vent opening means, means are provided for rotatably mounting the housing cover on the base insert means including a bearing pin provided on the housing cover, and a hub provided on the base insert means, the bearing pin is disposed so as to be coaxial with respect to a longitudinally extending center axis of the base insert means, the cover housing includes a chamber, the bearing pin includes at least one passageway for communicating the vent opening means with the chamber, the bearing pin further includes a plurality of tongues adapted to be radially compressible with respect to the longitudinally extending center axis of the base insert means under a spring tension, and the hub includes stop means cooperable with tongues of the bearing pin for axially fixing the housing cover relative to the base insert means, characterized in that the base insert means includes a plurality of labyrinth walls, and in that means are provided for communicating an interior of the vent cap with the atmosphere when the vent cap is installed on the vent opening of the container. ### Claim 34 (depends on 33) A vent cap according to claim 33, characterized in that the housing cover includes a plurality of labyrinth walls. ### Claim 35 (depends on 33, 34) A vent cap according to one of claims 33 or 34, characterized in that a plurality of tongues are provided on the base insert means on an end thereof opposite the housing cover, means are provided on each of the tongues for axially fixing the vent cap in the vent opening of the container, and in that the tongues are radially compressible with respect to a longitudinally extending axis of the base insert means. ### Claim 36 A vent cap adapted to be mounted on a vent opening of a container for accommodating a fluid, the vent cap comprising a housing cover, a base insert means for covering the housing cover, a vent opening means, means are provided on the base insert means, the bearing pin is disposed so as to be coaxial with respect to a longitudinally extending center axis of the base insert means, the cover housing includes a chamber, the bearing pin includes at least one passageway for communicating the vent opening means with the chamber, the bearing pin further includes a plurality of tongues adapted to be radially compressible with respect to the longitudinally extending center axis of the base insert means under a spring tension, and the hub includes stop means cooperable with tongues of the bearing pin for axially fixing the housing cover relative to the base insert means, characterized in that the base insert means includes a bead portion, and in that the housing cover includes means for accommodating the bead portion so as to enable an axial mounting of the housing cover on the base insert means.