Abstract: An apparatus is disclosed for adhering a synthetic resin gasket to a filtering element of an air filter. The apparatus incorporates a mold having a synthetic resin forming gasket cavity therein in which the synthetic resin gasket is formed. The cavity has an injection recess portion and an expansion recess portion. The two portions are separated by a movable mold element which may be positioned to substantially separate or substantially adjoin the injection recess and expansion recess portions. When the movable mold element is in the separation position, synthetic resin may be introduced into the injection recess position without contacting the filtering element. When the movable mold element is in the adjoining position, the resin may expand into the expansion recess until the resin contacts and adheres to the filter element. An automated version of this apparatus is also disclosed.

Abstract: A method for manufacturing an air filter consists of building in two stages around a paper filtering element previously prepared, an edge made of flexible foam, first injecting resin into a separate space from the filtering element, and then letting it expand until it anchors to it.An apparatus to carry out such method consists of a die in which the filtering element is inserted, around which a channel is formed where a mobile frame is sinked, whose shape corresponds to the filtering element one, in such a way as to define an injection recess separated from the filtering element, and an expansion recess adjacent to the filtering element, connected by the mobile frame lift, so that the resin can expand and anchor to the filtering element.

Abstract: A filter comprises a case for a fuel filter element and a cover that can be built according to two embodiments: one with holes for allowing the screwing of the filter onto a threaded base; and one with elbow-ducts projecting from the cover and integrally formed therewith. Both the cover and the case are of plastic material. The fastening of the cover to the case is obtained by means of a helical screw connection and a locking means, the locking means consisting of oblique teeth both in the case and in the cover acting as a ratchet gear arrangement for preventing unscrewing of the cover. A settlement chamber is formed at the bottom of the case having radial projections reinforcing the structure thereof.