| 摘要 |
<p>A pilot lamp wherein a light source and an axially reciprocable switching member are mounted in a housing supporting a switch which is actuatable by the switching member through the medium of a depressible actuator having a tubular section with a conical or pyramidal external surface which tapers in a direction toward the tip of the section and can expand the inner marginal portion of an annular membrane whose outer marginal portion is mounted in the housing. During insertion of the tubular section, its external surface expands the inner marginal portion of the membrane so that the latter sealingly engages the actuator while the actuator moves its section into engagement with the switching member. A shoulder on the switching member intercepts the inner marginal portion of the membrane during insertion of the tubular section to thereby ensure that such inner marginal portion expands during further insertion of the tubular section into the switching member. During extraction of the tubular section, e.g., to gain access to the light source, the membrane is prevented from leaving the housing by a ring which sealingly urges the outer marginal portion against an inclined internal surface of the housing and is held in the housing by a detent mechanism.</p> |
