Abstract: A spark-protected alternator has an external cavity on an end plate of the alternator housing with commutating (slip) rings on an alternator shaft extension and mating metal brushes positioned within the external cavity. The external cavity is effectively sealed from ambient atmosphere surrounding the alternator, to provide protection from sparks generated between the brushes and commutating rings wherein a minimum area of the housing end plate is utilized. Integral extensions of the end plate form side walls of the external cavity that partially radially surround the shaft extension and commutating rings. A brush holder in which the brushes are attached has projections which mate with slots in the side walls to radially close the external cavity, and an end cap (including a gasket) closes an open end of the external cavity, while the end plate effectively closes the other end of the external cavity.

Abstract: A housing having key portions of a resilient pad extending therethrough with a metal impregnated elastomer pad overlying the rear surface thereof, a sheet of insulating material having openings therethrough corresponding with the key portions and a plurality of contact areas on a printed circuit board overlying the insulating sheet and having a plurality of contacts on the rear surface thereof, a connecting link formed of a second sheet of insulating material having a plurality of areas of metal impregnated elastomeric material extending therethrough and corresponding in position with the contacts, a second PC board having a plurality of contacts in contact with the elastomeric areas of the connecting link and a frame compressing all of the components together to provide an electrical contact to the elastomeric material in the connecting link and complete a circuit between various contacts on the two printed circuit boards and provide a weather-tight multi-push button switch.