Determination of start and finish times of the working day in accordance with the European regulations for road transport drivers, uses a disk calculator with hours marked on middle disk and top disk covering number of required rest hours

摘要

The times are read from a manual calculator which has a base disk (1) with a sliding marker (2) on its periphery, part covering a disk (5) with 24 hour graduations. A top disk (8) has a part of larger diameter, covering part of the calibrated disk representing the required rest period. The disks rotate round a central axis (14), and allow earliest start and latest finish times to be read.