Heating cartridge with temp limiter - has switch which breaks heating current when preset cartridge temp is exceeded

摘要

The temperature limiter (20) for a heater cartridge (10) has a switch interrupting current flow when a first cartridge temperature has been exceeded. A metal rod (24) of high thermal conductivity is inserted into the cartridge and extends over its whole length. Its outer end is in contact with the temperature limiter. Preferably the temperature limiter is a switch with one or more bimetal strips. The temperature limiter may consist of a bimetal strip attached to the rod and its deformation operates a microswitch. The assembly is suitable both for heating liquids and solid objects, such as injection moulds.