Thermally responsive valve

A valve assembly comprising means providing a passageway having an entrance, a wall with a plurality of grooves formed therein and a sealing surface, a plug for occluding the passageway, and means for urging the plug out of the passageway, the plug comprising a plug body having a seal engageable with the sealing surface of the passageway, and the plug body also having a sidewall defining an internal chamber within the plug body, a plurality of openings in the sidewall, a ball situated in each of the openings, the diameter of each ball being greater than the length of the opening in which it is situated, cam means engageable with the balls for maintaining the balls in a condition in which they protrude outwardly from the openings into the grooves of the passageway, and temperature-responsive means for moving the cam means to release the balls for retraction into the openings, each groove extending into the passageway from the entrance, and having a circumferential portion with a surface engageable by one of the balls to lock the plug in the passageway, the grooves and the balls together providing bayonet connection means allowing the plug to be engaged with the passageway, and the seal engaged with the sealing surface, by inserting the plug into the passageway with the balls protruding outwardly from the openings and twisting the plug to cause the balls to move into the circumferential portions of the grooves, wherein the improvement comprises a helical ramp surface in each groove, extending from the circumferential portion thereof obliquely toward the entrance of the passageway, the helical ramp surface in each groove merging with said surface of the circumferential portion of the same groove and being engageable by a ball to urge the plug into the passageway as the plug is twisted.

A valve assembly comprising means providing a passageway connected to a liquid-containing system, the passageway having a wall with a plurality of grooves formed therein and a sealing surface, and a plug for occluding the passageway, the plug comprising a plug body having a seal engageable with the sealing surface of the passageway, and the plug body also having a sidewall defining an internal chamber within the plug body, a plurality of openings in the sidewall, a ball situated in each of the openings, the diameter of each ball being greater than the length of the opening in which it is situated, cam means engageable with the balls for maintaining the balls in a condition in which they protrude outwardly from the openings into the grooves of the passageway, and temperature-responsive means for moving the cam means to release the balls for retraction into the openings, wherein the seal and sealing surface, when engaged with each other, are positioned in the passageway between the balls and the liquid-containing system, whereby liquid in the liquid system is isolated from the balls, in which the temperature responsive means comprises a thermal actuator having a piston engaged with the cam means, and a thermally responsive, expansible material arranged to exert a force on the piston, and in which the plug body comprises an actuator housing containing the expansible material, the actuator housing forming an end portion of the plug and being located on the plug body so that it is also positioned in the passageway between the balls and the liquid-containing system when the seal and the sealing surface are engaged with each other, whereby heat can flow directly from the expansible material to the liquid system through the actuator housing.

A temperature-sensitive device for releasing liquid from a liquid-containing system comprising:

• means providing a drain opening in the liquid-containing system, the drain opening being surrounded by a surface;
• and
• plug means insertable into the drain opening for blocking the flow of liquid from the system through the drain opening, the plug means comprising latch means, movable between a released condition and an engaged condition, for maintaining the plug means in its inserted condition in the drain opening when the latch means is in its engaged condition and releasing the plug means from the drain opening when the latch means is moved to its released condition, means for automatically effecting complete removal of the plug means from the drain opening upon release of the plug means by the latch means, and a temperature-sensitive means carried by the plug means for automatically releasing the latch means when the temperature-sensitive means reaches a predetermined temperature, whereby the plug means is automatically and completely removed from the drain opening;
• wherein the improvement comprises shielding means connected to and surrounding the plug, and engageable with the surface surrounding the drain opening when the plug is in its inserted condition, the shielding means being for preventing paint from sealing the plug to the drain opening, and being sufficiently flexible to allow the removal-effecting means to remove the plug from the drain opening even when the shielding means itself is painted.

A temperature-sensitive device for releasing liquid from a liquid-containing system comprising:

• means providing a drain opening in the liquid-containing system;
• and
• plug means insertable into the drain opening for blocking the flow of liquid from the system through the drain opening, latch means, movable between a released condition and an engaged condition, for maintaining the plug means in its inserted condition in the drain opening when the latch means is in its engaged condition and releasing the plug means from the drain opening when the latch means is moved to its released condition, a temperature-sensitive means carried by the plug means, and responsive to the temperature of the liquid in the liquid-containing system, for automatically releasing the latch means when the liquid in the liquid-containing system becomes very cold, whereby the plug means is automatically removed from the drain opening;
• wherein the improvement comprises means, connected between the latch means and the plug means for temporarily preventing the temperature-sensitive means from automatically releasing the latch means when the plug means is inserted in the drain opening so that the latch means will not be released as the temperature of the liquid in the liquid-containing system rises from a temperature below a temperature at which it would cause release of the latch means.