Abstract: An air prefilter is disclosed for use with internal combustion engine air filters of the type having replaceable filter elements. The prefilter has a perforated sleeve connected between the usual intake openings and the filter element of the conventional air filter. This perforated sleeve is enveloped by an open-pore foam filter medium, which is of such porosity that engine intake air primarily passes therethrough rather than through the intake openings of the conventional air filter. The prefilter prevents foreign matter and water vapor from reaching and blocking the conventional filter element, which blocking causes the engine to receive insufficient air for efficient combustion. When the prefilter medium is saturated or blocked with impurities, the conventional air filter operates as usual, until the prefilter medium is cleaned or replaced. An adjustable deflector helps prevent foreign matter from blocking the prefilter medium.

Abstract: The specification describes an improved humidifier pad and a method of making the pad. The pad comprises a fibrous layer provided with means which substantially eliminate the flow of water picked up by the fibrous layer along the length of the pad so that when the pad is in use on a rotating drum, the water that is picked up is held in the pad for vaporization rather than flowing back downwardly to the pickup point.

Abstract: A humidifier pad is disclosed which comprises a body portion having opposing surfaces. In the body portion there are a plurality of openings which allow communication between one of the surfaces to another of the surfaces. A pluality of projections extend from at least one of the surfaces. The pad may be formed in the shape of a drum wherein the drum comprises one or more pads placed within one another. Flexible plastic material which resists hydrolytic aging may be used in the manufacture of the pad to provide the consumer with a long-lasting easily maintained unit.