Abstract: A breather chamber is located in a blow-by gas passage to separate oil from blow-by gas. A partitioning member partitions the interior of the breather chamber into a plurality of spaces. The partitioning member is arranged such that the spaces extend along the flowing direction of the blow-by gas and that an adjacent pair of the spaces are connected at ends in the flowing direction. A separating member is provided in at least one of the spaces. The separating member obstructs the flow of the blow-by gas in the associated space, thereby separating oil from the blow-by gas. Therefore, oil is separated from the blow-by gas securely and is prevented from being brought out of the breather chamber.

Abstract: A breather chamber is located in a blow-by gas passage to separate oil from blow-by gas. A partitioning member partitions the interior of the breather chamber into a plurality of spaces. The partitioning member is arranged such that the spaces extend along the flowing direction of the blow-by gas and that an adjacent pair of the spaces are connected at ends in the flowing direction. A separating member is provided in at least one of the spaces. The separating member obstructs the flow of the blow-by gas in the associated space, thereby separating oil from the blow-by gas. Therefore, oil is separated from the blow-by gas securely and is prevented from being brought out of the breather chamber.

Abstract: Disclosed is a process for producing a copper through-hole printed circuit board, which comprises forming a required pattern on a copper-clad laminated plate using a resist ink soluble in an alkaline aqueous solution, immersing the copper-clad laminated plate in an aqueous solution of a salt of an alkylimidazole compound represented by the following general formula ##STR1## wherein R.sub.2 represents an alkyl group having 5 to 21 carbon atoms, R.sub.4 represents a hydrogen atom or a methyl group, and HA represents an organic or inorganic acid, to form on the copper surface of the copper-clad laminated plate an etching resist film composed of the alkylimidazole compound, drying the resulting copper-clad laminated plate, and then treating it with an alkaline etching solution.