Procedure to Clear False Overtemperature Conditions
Original Publication Date: 1980-Mar-01
Included in the Prior Art Database: 2005-Feb-13
Many copier machines with hot roll fusers have a fuser temperature sensing system which requires reasonably good ohmic contact between graphite shoes and the metal surface of the hot roll. If the shoes lose contact with the hot roll, a fuser "open circuit" is sensed which is identical to an overtemperature condition in which the thermal fuse melts, creating an open circuit. Once an overtemperature condition is sensed, the machine is shut down and recovery can occur only after circuit continuity has been reestablished. Since poor shoe contact appears to be fuser overtemperature, this also results in machine shut-down.