Abstract: A switch construction, comprises a support base upon which is mounted a spring of hemispherical outline which includes an annular lower portion with a plurality of upstanding circumferentially spaced curved segment portions which are spaced apart at their tops to define a centering area for a top cover which is pivotal on the base. A contact member is in the form of a lever which is pivoted at one end on an upstanding portion of the base, and has an opposite engagement end which, for example, is movable along a rheostat control for the purpose of changing the setting thereof. The switch contact member is provided with a central substantially hemispherical cam portion which cooperates with a foot actuated cover and a similar cam portion defined on the cover which is located within the central part of the supporting spring.