Valved automotive radiator cap

A valved radiator cap assembly capable of being removably mounted on a filling tube of an automotive radiator of the type that includes a cylindrical shell having first and second ends, a flat circular flange extending outwardly from said first end, a pair of oppositely disposed first tabs depending from said flange, and a ring-shaped lip projecting inwardly from said second end of said shell, said shell having an opening therein between said first and second ends that is in communication with an overflow line, said assembly permitting water under pressure to be discharged into said radiator from a nozzle having a tapered end without removing said assembly from said filling tube, said assembly permitting water and steam to escape from said radiator through said opening to said overflow line when the pressure in said radiator rises above a predetermined level, said assembly permitting a negative pressure in said radiator to be partially relieved by flow of air thereinto from the ambient atmosphere as said radiator cools, said assembly including:

• a. a cover removably mounted on said first end of said shell, said cover including a pair of oppositely disposed second tabs that engage said first pair of tabs to maintain said cover on said filling tube, said cover having a central opening therein;
• b. an exteriorly disposed tubular resilient body that projects outwardly from said cover, is permanently secured to said cover, and is in communication with said central opening, with said resilient body capable of being sealingly engaged by said nozzle when the latter is in pressure contact with said body;
• c. an elongate valve body that depends from said cover, said valve body having a bore and a counterbore therein, said counterbore in communication with said central opening, and said bore and counterbore at their junction defining and inward and upwardly tapering valve seat;
• d. a rigid ball longitudinally movable in said bore and capable of sealingly engaging said valve seat, said ball of less diameter than that of said bore;
• e. a transverse pin supported by said valve body below said ball, said pin having outwardly projecting end portions;
• f. a first compressed helical spring disposed in said bore with one end thereof in abutting contact with said ball and the other end in contact with said pin, said first spring having a compression ratio sufficient to maintain said ball in sealing contact with said seat with a first force to permit water to flow from said nozzle through said bore when the pressure on said water is sufficiently great as to exert a second force on said ball greater than said first force;
• g. a tubular member slidably and sealingly movable in a longitudinal direction on the exterior surface of said valve body, said member having a pair of oppositely disposed, elongate, longitudinal slots therein that are slidably engaged by said end portions to limit the range of movement of said tubular member relative to said valve body and to prevent inadvertent separation of said tubular member and valve body;
• h. an outwardly projecting ring-shaped valve member secured to the end portion of said tubular member most remote from said first spring, said valve member having first and second oppositely disposed sides;
• i. abutment defining means on said tubular member adjacent said cover;
• j. a resilient sheet of material bonded to said first side of said valve member;
• k. a second compressed helical spring that encircles said tubular member, said second spring having one end in contact with said abutment means and the other end in contact with said second side of said valve member, said second spring at all times tending to maintain said resilient sheet in pressure sealing contact with said ring-shaped lip with a third force, with a portion of said resilient sheet at all times in communication with the interior of said radiator, and when pressure of fluid in said radiator exerts a fourth force on said resilient sheet greater than said third force said tubular member, valve member and resilient sheet will move towards said cover to allow fluid to flow to said overflow line from said radiator until said third force is greater than said fourth force, said ball when there is a negative pressure in said radiator of sufficient magnitude will move out of sealing contact with said valve seat against the first force of said first spring to allow air from the ambient atmosphere to flow into said radiator until said first force returns said ball to sealing engagement with said valve seat.