Patent ID: 6178988
Filing Date: 2001-01-30
Classification: E03B,F16K,Y10S,Y10T

Abstract:
A spool apparatus for use with a hydrant, the hydrant including an elongated housing which forms an internal sealing surface about a chamber along an axis, the chamber including a first sealing section formed by a sealing surface and an enlarged section adjacent the sealing section, the sealing section and enlarged section having first and second width dimensions perpendicular to the axis, respectively, the second dimension greater than the first, the housing also forming a housing opening at one end and first and second openings in the sealing and enlarged sections, one of the openings being an inlet and the other being a drain, the apparatus comprising:at least two annular seals;a spool member forming an external surface having first and second circumferential recesses which receive the seals, an open surface between the first and second recesses, respectively, the member also forming an internal passageway having an outlet end which opens into the housing opening, the member forming a passageway passage between the passageway and the open surface, when positioned in the chamber, the member moveable along the axis between at least:a first position wherein the first and second seals seal between the external and sealing surface on opposite sides of the first opening allowing passage from the passageway passage to the first opening; anda second position wherein the first seal seals between the external and sealing surfaces, the second seal within the enlarged section and the passageway passage at least partially open to the enlarged section and hence to the second opening;the member forming a venting passage from the second recess to a portion of the external surface on the side of the second recess opposite the first recess such that, when the member moves from the first to the second postion, pressure within said hydrant causes the second seal to move within said second recess such the venting passage in unblocked and the pressure within said hydrant is released into said enlarged section.