Types IP-3 (1906 to 1908), IP-4 (1908 to 1916)	Back	Up	Next
The IP-3 was a redesign of the IP-2 using the Form 4 prepayment device instead of the Form 3 device. The IP-3 had the knob mounted on the prepayment mechanism, but any strain on the knob was prone to damage the mechanism, so it was soon superseded by the IP-4 which had the knob in the cover and had a notch on the back that operated a lever on the mechanism. The space above the register in both versions was for a scale showing the number of coins remaining to the user's credit.	Joe Maurath Jr. collection