| 摘要 |
<p>1. Thermal-magnetic trip device with a mechanism (40) of an electric circuit breaker comprising : - a stationary core (18) associated with a movable core (20) sliding by means of an air-gap (22), - a tubular control coil (12) surrounding coaxially said stationary and movable cores (18, 20), the air-gap (22) being crossed by a magnetic flux due to the passage of the current in the coil (12), - a spring (36) resetting the movable core (20) in spreaded position when the current intensity for excitation of the coil (12) is lower than the electromagnetic trip threshold, - a thermomechanical sensor (44) of shape memory effect alloy, sensitive for the temperature rise of the control coil (12), - and unlocking means cooperating with the movable core (20) and the thermomechanical sensor (44) to ensure the automatic tripping of the mechanism (40), characterized by the fact that the thermomechanical sensor (44) of shape memory effect alloy comprises a helical spring (46) arranged in a closed space (42) insides the insulating duct (14) supporting the coil (12), and that the ampere-turn number of the coil (12) is constant for all sizes of a range.</p> |
