Improved Retractable Bollard

摘要

This invention relates to a retractable bollard including an embedded outer housing having an open end and a closed end; a ram slideably mounted within the outer housing; and means for injecting fluid into, and means for removing fluid from, a chamber within the retractable bollard to move the ram relative to the outer housing between a retracted position and an extended position. The chamber is bounded by one or more sliding surfaces and one or more seals configured to move in sealing relationship relative to the sliding surfaces and the ram is able to be completely removed from the outer housing without separating the seals from the sliding surfaces.

主权项

1. A retractable bollard comprising:
an embedded outer housing having an open end and a closed end; a ram slideably mounted within the outer housing, the ram having an outer surface; and a mechanism for injecting fluid into, and a mechanism for removing fluid from, a chamber within the retractable bollard to move the ram relative to the outer housing between a retracted position and an extended position, the outer surface of the ram being exposed to the surroundings of the bollard when the ram is in the extended position; wherein: the chamber is bounded by at least one surface of the ram, one or more sliding surfaces and one or more seals configured to move in sealing relationship relative to the sliding surfaces; and the ram is able to be completely removed from the outer housing without separating the seals from the sliding surfaces.