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(11) | EP 0 318 265 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Improvements relating to thermally responsive electric switches |
| (57) A steam sensor for a water boiling vessel consists of a moulded plastics body portion
defining spaced-apart pivotal support positions for an overcentre bridge consisting
of a bimetal and a trip-lever pivotally journalled together at the centre of the
bridge and each pivotally journalled at its other end in one of the support positions
of the moulding. The trip-lever is arranged to perform snap-action movement in response
to heating of the bimetal irrespective of the fact that a plain (non-prestressed and
non-snap-acting) bimetal is used and can be coupled either directly to a switch sub-assembly
in the steam sensor or indirectly via a Bowden cable or the like to a separate switch
incorporated in a remote element protector unit. The switch sub-assembly in the steam
sensor may be designed to be plugged directly into a socket formed in an element protector
unit in which case the switch of the steam sensor is connected electrically in series
with a switch in the element protector, and the same electrical arrangement can be
obtained with the steam sensor and the element protector spaced apart from each other
and interconnected by means of a lead having appropriate plug and socket terminations.
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