| 摘要 |
A thermally sensitive control 1 for an electric heater 2 comprises back-up protection means in the form of a pre-loaded spring mechanism comprising an actuating spring 25 which is held in normal use of the control in a compressed condition by retaining means in the form of push rod 27. The push rod 27 is adapted to soften and deform in the event of serious overheating of the heater consequent upon failure of a primary protector switch means of the control, whereby the spring 25 is released and moves an operating member 30 into engagement with a set switch contacts 15 to open the contacts and disable the heater. <IMAGE> |
