Abstract: A dot-matrix impact printer includes a print head in a housing for printing a recording sheet fed around a platen. The recording sheet is pressed against the platen by a sheet presser roller. A roller cover or a flap is disclosed as a sound insulating wall closely to the sheet presser roller and has an edge held against the housing. The space above the print head is closed by the housing, the platen, the sheet presser roller, and the platen, so that the impact noise produced when the printer is in operation will not leak out of the housing, while at the same time the recording sheet fed around the platen is not blocked by the closure mechanism.

Abstract: A deceleration switch for detecting deceleration in excess of a certain magnitude which, for instance, may be indicative of a vehicle crash, comprising: a pair of electrodes having internal and external ends; a contact set electrically connected to the internal ends; a mass supported by a spring or the like and adapted to move from a neutral position to an active position for actuating the contact set under its inertia force when deceleration of a certain magnitude is applied to the switch; and a circuit for checking the electric conductance between the internal end and the external end of at least one of the electrodes. The circuit may consist of either lead wires connected to the internal and external ends of the electrodes or a resistor connected across the internal ends of the electrodes.

Abstract: A deceleration switch for detecting deceleration in excess of a certain magnitude which, for instance, may be indicative of a vehicle crash, comprising: a contact set electrically connected to a pair of output terminals; a mass supported by a spring member and adapted to move from a neutral position to an active position for actuating the contact set under its inertia force when deceleration of a certain magnitude is applied to the switch; and a circuit for monitoring the electric conductivity between two points of the spring member for detecting any break in the spring member. An extra terminal may be provided, in addition to the output terminals, for permitting access to the two points. Alternatively, by connecting a resistor across the contact set, which consists of an normally open contact set, it is possible to detect any fracture in the spring member or in the contact set by monitoring the electric resistance across the output terminals of the deceleration switch.

Abstract: A relative positional relation detecting system has a detector for the recognition of and inspection by use of a predetermined identification mark provided on each of at least two members to be put in a predetermined relative position to each other. The detector comprises an irradiation device for irradiating the identification mark with rays of light, a light detection device for detecting reflected rays of light from the identification mark, and a judging device for judging whether or not the members are put in the predetermined relative position, depending on a detection signal from the light detection device.

Abstract: A connector housing composed of a block of an insulating material wherein a plurality of contact receiving holes penetrating from the front surface to the rear surface of said block are formed in at least one row and a slit is formed in the rear surface of the block to communicate said connector receiving holes with one another, whereby the connector housing can be used in common for a connector for wire connection and a connector for FFC connection.