US Patent 6963039 Button knob waterproofing design

A waterproof button knob includes an elastic button seat with a housing trough mating with a button port of a case. The button seat isolates the interior and the exterior of the case to achieve waterproofing. The housing trough has a plurality of apertures on the bottom. The housing trough holds a button cap that has a plurality of button stems extended downwards to pass through the apertures and form a tight coupling. The button stems may be moved to hit switches located in the case.