Drum counter for addition of subtraction - has contact holding until associated functions are completed and has cam contacts to operate magnet switch circuits

摘要

The adding and subtracting drum counter has an electromagnet acting on the drums for addition or subtraction from a remote control through separate switching levers and spring-loaded transport ratchets on a common driving ratchet wheel fixed pivoted locking ratchets for the drive ratchet. The addition or subtraction magnet is mechanically coupled to an armature contact which is closed in the attracted position to maintain closed a circuit until it has effected to completion an additional function, which forms parts of the addition or subtraction overall process.