Electrical switch
OwnerMemie Mei Mei Wong, Sam Yun Sum Wonginventors
Life of this patent
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Abstract
An electrical switch has a casing, fixed and moving contacts, and an internal operator turning and moving the moving contact relative to the fixed contact for switching. The casing has an opening through which an engagement part of the operator is accessible from outside for engaging a pull chain to turn the operator. The casing has a tubular part by which the switch may be mounted and through which the pull chain extends. The tubular part, being molded, has an inner surface defining a passage for the pull chain, an outer surface bearing a screw thread for engagement by a threaded nut, and, in a transverse cross-section, four recesses between the inner and outer surfaces to alleviate deformation of the screw thread due to shrinkage in molding.
Claims21
An electrical switch comprising:
- a casing;
- at least one fixed contact and at least one moving contact in the casing;
- an operator supported internally in the casing for movement to move the moving contact into and out of contact with the fixed contact for switching, the operator having an engagement part;
- and
- an elongate pliable member that is partially external to the casing, wherein the casing has an opening through which the engagement part of the operator is accessible from outside the casing for engagement with the pliable member which, upon pulling, operates the operator and moves the moving contact for switching.
An electrical switch comprising:
- a casing;
- at least one fixed contact and at least one moving contact in the casing;
- an operator supported in the casing for movement to move the moving contact into and out of contact with the fixed contact for switching;
- and
- an elongate pliable member associated with the operator and operating the operator upon being pulled, wherein
- the casing has a protruding tubular part by which the electrical switch may be mounted and through which the pliable member extends from the casing for pulling, and
- the tubular part, is molded, has an inner surface defining a passage for the pliable member, an outer surface bearing a screw thread for engagement by a threaded nut member, and, in a transverse cross-section, at least one void space between the inner surface and the outer surface, alleviating deformation of the screw thread due to shrinkage of the tubular part.
Dependencies are inferred from the claim text.