| 摘要 |
A solenoid actuator is described. The solenoid actuator comprises an armature, pole piece(s), electromagnet coil(s) arranged, in response to energisation, to cause travel of the armature between first and second positions along a direction of travel, wherein travel of the armature is bounded in the direction of travel by the pole piece(s), permanent magnet(s) positioned and orientated for latching the armature in at least the first position when the armature is in the first position and spring(s) arranged to bias the armature. The spring(s) is (are) configured to provide sufficient force so as to prevent the armature from latching in second position and the at least one spring has a (net) spring constant, k (N/µm), in a range of 5 Ncm -2 × A/t to 20 Ncm -2 × A/t, where A is the active area of a pole piece in cm 2 and t is the gap length in µm between the armature and a pole piece. |
