Abstract: A gasket for use in a cylindrical alkaline-manganese dioxide cell is molded by injecting a molten resin into a mold assembly having a male mold having an injection gate formed in a cylindrical space and a projection formed in a narrow space and of which a side facing the cylindrical space is chamfered or curved, and a female mold having at least any one of an eject sleeve or ejection pin. The gasket is used to seal an opening of a can of the cylindrical alkaline-manganese dioxide cell. In the gasket, the boundary between a thin portion and hob portion thereof is chamfered or curved and the boundary between the thin and diaphragm portions is formed like a generally vertical edge.

Abstract: A data communication system comprising a master station and n number of substations, each substation comprising a receiving photocoupler and a transmission photocoupler, and wherein a particular substation may be connected into a transmission line leading to the master station by connecting the receiving photocoupler in series in parallel circuit to the transmission line and wherein data transmission from the master station to the substation is accomplished by means of a current supplied forward with respect to the receiving photocoupler of the substation, and data transmission from the substation to the master station is done by means of a current supplied reverse with respect to the transmission photocoupler of the substation.

Abstract: A redundancy system for data communications upon two duplicate communication channels, each having transmission and reception circuits, characterized by a switching circuit for selecting one of said two communication channels, a single error detection circuit for detecting an error in the signal transmitted, and a control circuit for the switching circuit arranged to cause said two communication channels to alternately transmit signals when both the channels are in normal operation, and to cause one of said two channels to be selected when the other fails. The two channels share the error detection circuit and the control circuit and can therefore be built at a reduced cost and operated efficiently. Since the two channels are regularly checked for errors, they are operated with increased reliability.