This invention pertains to novel multiple quaternary ammonium salts and their derivatives represented by the formula: wherein each R1, R\u20321, R2, R\u20322, R3, R\u20323, R4 or R5 is independently selected from the group consisting alkyl, aryl, aralkyl and \u2014CH2\u2014CH\u2014CH2N+R1R2R3; wherein one or more R6 group is selected from the group consisting of: and wherein An\u2212 is an anion. The energy delivery system includes an overtube. Consequently, according to the disc cramp device of the present invention, the number of components is reduced, and the height of the space for transferring the disc can be made large with respect to the height of the entire device, in addition to which, the driving force in a cramping and uncramping operations can be made small. The ice maker is provided with a front face plate 42 for connecting the frame 32 and the drive unit 50 in the longitudinal direction along one side of the ice-making container 34.