Apparatus for aerating liquids

In a portable apparatus for aerating liquids comprising a casing, an aerating head mounted to the casing and including a nozzle and seal means surrounding the nozzle, gas supply means connected to the aerating head and operable to supply gas to said nozzle, a platform for supporting and contacting a bottle having an open mouth and containing lquid to be aerated, means for raising the platform to lift the mouth of said bottle into sealing engagement with said seal means, said platform raising means including rotary cam means supported rotatably on a cam shaft in the casing, an operating member located oustide the frame means and coupled to the cam means for rotating the cam means manually, and a cam follower connected to the platform and in cooperating engagement with the cam means, the improvement which comprises a tubular stem slidable within said casing and fixed to the platform and extending downwardly therefrom having upper and lower abutment surfaces spaced apart and facing towards each other, a coil spring compressed within said tubular stem between the abutment surfaces, the cam follower being slidably and resiliently mounted to said tubular stem and including a flange received within said tubular stem between the lower abutment surface and the adjacent end of the spring, the coil spring being precompressed to a predetermined value between the upper abutment surface and the cam follower to urge the flange against the lower abutment surface, and the spring being adapted to become further compressed when the bottle mouth engages the seal means with a predetermined force and said flange moves out of engagement with the lower abutment surface on raising the platform, whereby to ensure a tight seal between the bottle mouth and the seal means and to prevent bending of the cam shaft.