Abstract: An amphoteric surfactant system which, in use, is nontoxic to marine or aquatic life, and which contains as amphoteric surfactant at least one amido betaine of a specified class. Multipurpose detergent systems based upon such betaine and incorporating detergent builders and other adjuncts, all selected to be similarly nontoxic. Advantageously, the detergency builder is sodium hydroxide or a suitable sodium salt such as the carbonate, sesquicarbonate, tripolyphosphate, or other. Also advantageously there is incorporated a chelating agent which is advantageously a sodium salt or compound such as the sodium salt of EDTA; and other adjuncts, such as a soil-suspending agent or optical brightener, are also useful additives. A particular advantage of the composition according to this invention is that it provides washing effluents which are substantially nontoxic to marine or aquatic life, other than microorganisms.

Abstract: An audible signal generator comprises a coil, a pole piece, and an armature movably mounted with respect to the pole piece so that one end of the armature approaches the pole piece upon energization of the coil. The pole piece has a pair of spaced protrusions that extend toward the one end of the armature, and a cantilever spring member is supported on the pole piece so as to extend between the spaced protrusions. The one end of the armature has a protrusion that extends toward the pole piece and is located so as to engage the portion of the spring member in between the spaced protrusions of the pole piece.