Patent ID: 8138871

Claim:
A pole tube of a solenoid actuator comprising: three joining partners including: a non-magnetic intermediate piece including a first intermediate end face and a second intermediate end face; a pole piece including a pole end face configured to join the first intermediate end face at a first joining region; and a tube piece including a tube end face configured to join the second intermediate end face at a second joining region, wherein a first and a second of the three joining partners are configured to be connectable to each other using electric fusion at a corresponding fusion joining region corresponding to one of the first and second joining regions, wherein the first joining partner includes a first material and the second joining partner includes a second material having a different conductivity than the first material, a resistivity of the first material being higher than a resistivity of the second material, wherein a respective end face at the fusion joining region of the second joining partner has a smaller cross-sectional area than a respective end face at the fusion joining region of the first joining partner, and wherein a respective part of the first joining partner disposed in the fusion joining region is configured to have an electrical resistance substantially equal to an electrical resistance of a corresponding part of the second joining partner disposed in the fusion joining region.