Vehicle tachometer for recording journey speeds and driving periods on disk

摘要

The tachometer records on a disk (21) on the turntable of a cassette (11) inserted below recording head needles (18A,18B,18C) in the casing (1) of the unit. To ensure accurate location of the cassette and a firm hold, a positioning pin (70A) with a V-shaped head projects from an inner plate (50) into the inside of the case and corresponds with a V-shaped groove (12A) at the centre front of the cassette. This holding system, or an alternative axial pressure system, compensates for any play between cassette and cassette holder, thereby ensuring accuracy and reliability. The size of the tachometer and cassette can be minimised.