Patent ID: 6050207
Filing Date: 2000-04-18
Classification: E02D

Abstract:
A sealed liquilift, comprising:a) an outside casing, disposed in a vertical orientation, having a bottom and a sidewall, the sidewall having an upper rim and substantially uniform interior configuration and size throughout its vertical length;b) a cover, mating with the outside casing and being separably attached to the upper rim thereof, having a first seal means to effect a seal between the cover and the outside casing, and comprising a first bearing means and a second seal means centrally disposed therein;c) a lift rod, having a top, and mating with and being slidably disposed within the first bearing means and the second seal means of the cover;d) a pontoon, having a top, a bottom and a sidewall, and a sealed cavity therewithin, and being attached to the lift rod, wherein a portion of the sidewall has a configuration and size to cooperate with the interior configuration and size of the outside casing, the pontoon being slidably disposed within the outside casing;e) an operating liquid confined within the liquilift, and controllably distributed between the outside casing and the pontoon;f) pump means for transferring a controlled amount of the operating liquid between the outside casing and the sealed cavity;g) control means for activating the pump and controlling the amount of operating liquid to be transferred between the outside casing and the sealed cavity;h) a power supply to provide power to operate the control means and the pump means;i) vent means to equalize air pressure within the outside casing and within the pontoon with ambient atmospheric pressure; andj) stop means to limit the vertical motion of the lift rod and pontoon attached thereto within the outside casing, thereby determining the lowest possible position of the lift rod and pontoon within the outside casing,wherein the first and second seal means, and the outside casing and cover cooperate to exclude from the liquilift any external liquid present outside the liquilift.