Fluid handling – Line condition change responsive valves – With separate connected fluid reactor surface
Reexamination Certificate
2000-03-23
2001-09-04
Hepperle, Stephen M. (Department: 3753)
Fluid handling
Line condition change responsive valves
With separate connected fluid reactor surface
C137S505340, C137S557000
Reexamination Certificate
active
06283146
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a pressure reducing valve in which a secondary fluid pressure is set by actuating a cylindrical handle and a pressure gage is disposed in the handle (hereinafter referred to as “a gage-in-handle type pressure reducing valve”).
Japanese Utility Model Registration Application Post-Examination No. 4-45043 discloses a gage-in-handle type pressure reducing valve in which a valve chamber is disposed between a primary-side port (supply port) and a secondary-side port (output port), and a main valve element (supply valve element) in the valve chamber is urged toward a main valve seat (supply valve seat) by a valve spring (return spring). The main valve element is also urged away from the main valve seat by a pressure regulating spring fitted between a feedback member (diaphragm) and a pressure regulating spring retainer. In addition, a pressure gage is disposed in a cylindrical handle, and a feedback chamber between the feedback member and the valve chamber communicates with the pressure gage through a pressure introducing communicating passage. The axial position of the pressure regulating spring retainer is adjusted with the handle.
In the above-described prior art, the pressure introducing communicating passage for introducing the pressure in the feedback chamber into the pressure gage comprises pressure introducing holes in a valve body wall and a bonnet wall and a passage in a pressure regulating screw. A considerably large number of man-hours is needed to form the pressure introducing holes in the valve body wall and the bonnet wall by machining. In addition, it is necessary to provide four O-rings in order to make the passage in the pressure regulating screw air-tight. Thus, the prior art is unfavorably complicated in structure and costly.
SUMMARY OF THE INVENTION
A first object of the present invention is to provide a gage-in-handle type pressure reducing valve designed so that the feedback chamber and the pressure gage are communicated with each other through a communicating passage between a feedback member and a pressure gage guide without using a pressure introducing hole in the valve body wall or the bonnet wall.
A second object of the present invention is to provide a gage-in-handle type pressure reducing valve designed to minimize friction occurring in a mechanism for converting the rotation of the handle into an axial movement of the pressure regulating spring retainer.
To attain the above-described objects, the present invention is applied to a gage-in-handle type pressure reducing valve wherein a valve chamber is disposed between a primary-side port and a secondary-side port, and a main valve element in the valve chamber is urged toward a main valve seat by a valve spring. The main valve element is also urged away from the main valve seat by a pressure regulating spring fitted between a feedback member and a pressure regulating spring retainer. A pressure gage is disposed in a cylindrical handle, and a feedback chamber between the feedback member and the valve chamber communicates with the pressure gage through a pressure introducing communicating passage. According to a first arrangement of the present invention, a pressure regulating nut is rotatably supported in a bonnet. The pressure regulating nut has an internal thread. The pressure regulating spring retainer is supported in the bonnet so as to be axially movable but unable to rotate. The pressure regulating spring retainer has a tubular portion with an external thread. The internal thread of the pressure regulating nut is in engagement with the external thread of the tubular portion of the pressure regulating spring retainer. A pressure gage guide is connected to the pressure gage. The pressure gage guide is supported in the tubular portion of the pressure regulating spring retainer so that the pressure gage guide and the pressure regulating spring retainer are axially movable but unable to rotate relative to each other. A communicating hole is formed in the feedback member so as to communicate with the feedback chamber. The communicating hole is communicated with the pressure gage guide through a communicating line of the pressure introducing communicating passage. Rotation of the handle causes the pressure regulating nut to rotate, and this, in turn, causes the pressure regulating spring retainer to move axially.
According to a second arrangement of the present invention, the pressure regulating nut in the first arrangement is supported in a bearing hole provided in the bonnet. The pressure regulating nut has a flange at the lower end thereof and further has radial bolt holes in the upper end portion thereof. The pressure gage guide has an annular groove on the outer peripheral surface of the upper end portion thereof, so that the distal end portions of bolts screwed into the bolt holes of the pressure regulating nut are engaged with the annular groove of the pressure gage guide.
According to a third arrangement of the present invention, a hollow tube guide is slidably fitted in a sliding hole provided in the pressure gage guide in either of the first and second arrangements. The hollow tube guide has a first hollow connector. The feedback member has a second hollow connector communicating with the communicating hole. The first hollow connector and the second hollow connector are connected to each other by a flexible tube.
According to a fourth arrangement of the present invention, the pressure gage guide in either of the first and second arrangements has a third hollow connector, and the feedback member has a second hollow connector communicating with the communicating hole. The third hollow connector and the second hollow connector are connected to each other by a flexible coiled tube.
According to a fifth arrangement of the present invention, a pressure introducing part is provided between the pressure gage and the pressure gage guide in the second arrangement. The pressure introducing part has an engagement portion hermetically engaged with a large-diameter hole provided in the pressure gage guide.
According to a sixth arrangement of the present invention, the pressure gage guide in either of the first and second arrangements has a hollow guide portion at the distal end thereof. The feedback member has a hollow projecting portion with a sliding hole. The hollow guide portion is slidably and hermetically fitted in the sliding hole of the hollow projecting portion.
It should be noted that the term “communicating line” as used herein means a pipe, a pipe-shaped member, a tube, a tubular member, a hollow member, etc. having the function of providing communication, exclusive of a passage and a pressure introducing hole formed in the valve body wall or the bonnet wall. The term “a communicating line of the pressure introducing communicating passage” means that the communicating line is a part of the pressure introducing communicating passage. The third to sixth arrangements each limit the communicating line in the first arrangement.
According to the present invention, the feedback member is formed with a communicating hole communicating with the feedback chamber, and the communicating hole in the feedback member is communicated with the pressure gage guide through a communicating line. Therefore, the feedback chamber and the pressure gage can be communicated with each other through the communicating passage between the feedback member and the pressure gage guide without using a pressure introducing hole in the valve body wall or the bonnet wall. Accordingly, the structure is simplified, and the cost is reduced.
According to the present invention, further, a pressure regulating nut is rotatably supported in the bonnet, and a pressure regulating spring retainer is supported in the bonnet so as to be axially movable but unable to rotate. A pressure gage guide is connected to the pressure gage. The internal thread of the pressure regulating nut is engaged with an external thread formed on a tubular portion of the pressure regulating spring retainer. The
Baker & Botts L.L.P.
Hepperle Stephen M.
SMC Corporation
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