Air Bleeding Pipe Joint

Abstract

An air bleeding pipe joint has a pair of connection pipe portions, a branch pipe portion having an air bleeding hole in an inside thereof, a plug body, and an elastic annular sealing member providing an air-tight seal between a female fitting surface of the branch pipe portion and a male fitting surface of the plug body. The plug body is removably mounted to the branch pipe portion in threaded engagement therewith such that a seating surface of the plug body seats on a seated surface of the branch pipe portion. An air discharge path is provided on an upper end of the branch pipe portion and/or the plug body with respect to a sealing position at which the sealing member is disposed for discharging outwardly an air that leaks upwardly through the sealing position.

1 . An air bleeding pipe joint, comprising:
 (a) a pair of connection pipe portions inserted in and connected to a circulation pipeline for an engine cooling water;   (b) a branch pipe portion branched from the connection pipe portions in upstanding condition and having an air bleeding hole in an inside thereof, the air bleeding hole including an internally threaded portion and a female fitting surface under the internally threaded portion;   (c) a plug body removably mounted to the branch pipe portion for opening and closing the air bleeding hole, the plug body having a large diameter head portion of an upper end portion thereof with an under surface defining a seating surface, an externally threaded portion, and a male fitting surface under the externally threaded portion; and   (d) an elastic annular sealing member providing an air-tight seal between the female fitting surface of the branch pipe portion and the male fitting surface of the plug body mounted to the branch pipe portion;   the plug body being mounted to the branch pipe portion with the externally threaded portion in threaded engagement with the internally threaded portion such that the seating surface of the head portion seats on a corresponding upwardly facing seated surface of the branch pipe portion;   wherein an air discharge path is provided on an upper end of the branch pipe portion and/or the plug body with respect to a sealing position at which the sealing member is disposed, the air discharge path discharges outwardly an air that leaks upwardly through the sealing position.   
   
   
       2 . The air bleeding pipe joint as set forth in  claim 1 , wherein the plug body has an overlapping surface that overlaps with an overlapped surface of the branch pipe portion, the overlapping surface and/or the overlapped surface is provided with a recessed portion that allows an air to pass therethrough and defines at least a part of the air discharge path. 
   
   
       3 . The air bleeding pipe joint as set forth in  claim 1 , wherein the plug body has an overlapping surface that overlaps with an overlapped surface of the branch pipe portion, one of the overlapping surface and the overlapped surface is provided with a protruding portion protruding toward the other of the overlapping surface and the overlapped surface for creating a gap between the overlapping surface and the overlapped surface, and the gap defines at least a part of the air discharge path. 
   
   
       4 . The air bleeding pipe joint as set forth in  claim 1 , wherein the plug body has an overlapping surface that overlaps with an overlapped surface of the branch pipe portion, the overlapping surface and/or the overlapped surface is formed into a roughened surface having irregularities, and a gap in the roughened surface defines at least a part of the air discharge path. 
   
   
       5 . The air bleeding pipe joint as set forth in  claim 2 , wherein the recessed portion is provided in the seating surface of the overlapping surface and/or the seated surface of the overlapped surface. 
   
   
       6 . The air bleeding pipe joint as set forth in  claim 3 , wherein the protruding portion is provided on the seating surface of the overlapping surface or the seated surface of the overlapped surface. 
   
   
       7 . The air bleeding pipe joint as set forth in  claim 4 , wherein the seating surface of the overlapping surface and/or the seated surface of the overlapped surface is formed into the roughened surface having the irregularities. 
   
   
       8 . The air bleeding pipe joint as set forth in  claim 1 , wherein the air discharge path is in a form of a recessed path or a through-bore path that is provided in the upper end with respect to the sealing position, the recessed path or the through-bore path extends continuously from the sealing position and has an extremity end open to outside. 
   
   
       9 . The air bleeding pipe joint as set forth in  claim 1 , wherein the plug body, and a joint body comprising the pair of the connection pipe portions and the branch pipe portion are molded resin products. 
   
   
       10 . An air bleeding pipe joint, comprising:
 (a) a pair of connection pipe portions inserted in and connected to a circulation pipeline for an engine cooling water;   (b) a branch pipe portion branched from the connection pipe portions in upstanding condition and having an air bleeding hole in an inside thereof;   (c) a plug body having a head portion of an upper end portion thereof with an under surface defining a seating surface and adapted for opening and closing the air bleeding hole, the plug body being removably mounted to the branch pipe portion in threaded engagement therewith such that the seating surface of the head portion seats on a corresponding upwardly facing seated surface of the branch pipe portion; and   (d) an elastic annular sealing member providing an air-tight seal between the plug body and the air bleeding hole;   wherein an air discharge path is provided between the seating surface and the seated surface.   
   
   
       11 . An air bleeding pipe joint, comprising:
 (a) a pair of connection pipe portions inserted in and connected to a circulation pipeline for an engine cooling water;   (b) a branch pipe portion branched from the connection pipe portions in upstanding condition and having an air bleeding hole in an inside thereof;   (c) a plug body having a head portion of an upper end portion thereof with an under surface defining a seating surface and adapted for opening and closing the air bleeding hole, the plug body being removably mounted to the branch pipe portion in threaded engagement therewith such that the seating surface of the head portion seats on a corresponding upwardly facing seated surface of the branch pipe portion; and   (d) an elastic annular sealing member providing an air-tight seal between the plug body and the air bleeding hole;   wherein an air discharge path extends continuously from a sealing position at which the sealing member is disposed and has an extremity end open to outside.