(under subclass 511) Dispensers in which the biasing means has the sole function of increasing the resistance to material flow through a joint (contacting surfaces) between two relatively movable parts.
(1) Note. Where the biasing means either has the sole function of moving the movable element to operative (discharging) or nonoperative (nondischarging) position, or has such function in addition to the joint sealing function, see subclass 511 or other appropriate indented subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
337+, for discharge assistants with joint sealing biasing means.
490, for slitted, resilient diaphragms or nipples, the resilience of the diaphragm or nipple closing the slit.
494, for spring form, resilient or compressible flow controllers or closures that are pressure operable to open.
511, see note 1 above. 542, for packing type seals whether resilient or not where there is no additional resilient biasing means.
