Hydraulic fluid reservoir for a closed hydraulic system

Abstract

A vertically oriented air-tight bellows has its lower end connected to an opening in the top of the reservoir by an air-tight connection. A cover closes the upper end of the bellows and has secured thereto a fill inlet in communication with the interior of the bellows and carrying a removable cap. Vertical guide means guide the bellows in substantially vertical movement. Advantageously the bellows have means for lifting upwardly the upper end of the bellows and means for holding the bellows in an upwardly expanded position for filling. Preferably the cap for the fill inlet is transparent to permit viewing the hydraulic fluid in the bellows. A preferred embodiment has means to sight the position of the top of the bellows and a manually actuated bleed valve to vent gas from the interior of the bellows. A housing for the bellows is provided for situations where exposure to dirt particles is substantial. The capacity of an individual bellows may be varied widely and, if desired, overall capacity may be increased by employing a plurality of bellows.

Dependencies are inferred from the claim text.