Attracting Permanent Magnet
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
A magnetic actuator is used for applying variable peak follow-up pressure to a movable electrode in a resistance welder. The pressure applied during the resistance welding process is developed using the combination of a positive driving force and a magnetic breakaway force. The magnetic force which must be overcome by the driving force is developed first by a permanent magnet and additional magnetic force is provided by an electromagnet. Further, the air gap between the armature and the permanent magnet and electromagnet can be varied so as to vary the amount of force exerted upon the movable electrode of the resistance welder. In Fig. 1, there are a plurality of armatures 50 fixed to a freely movable shaft 55 which at one end bears against platen 56. Platen 56 carries the movable electrode 10.