Valves and valve actuation – Fluid actuated or retarded – Flexible wall expansible chamber reciprocating valve actuator
Reexamination Certificate
2000-06-14
2001-12-11
Shaver, Kevin (Department: 3754)
Valves and valve actuation
Fluid actuated or retarded
Flexible wall expansible chamber reciprocating valve actuator
C251S325000, C251S344000
Reexamination Certificate
active
06328277
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an automatic valve operated by a fluid. More particularly, the present invention relates to a compact automatic valve, the sealing property of which is high and the flow rate characteristic of which is excellent, which can be used for an ultra-pure water line in the semiconductor industry and also for various chemical lines in the chemical industry.
2. Description of the Related Art
The ultra-pure water line in the semiconductor industry and the various chemical lines in the chemical industry use a large number of pneumatic type automatic valves shown in FIG.
7
. As shown in
FIG. 7
, this pneumatic type automatic valve is composed of a main body section and a drive section. The structure of the main body section is the same as that of a stop valve. That is, when the disk section and the valve seat section are contacted with and separated from each other, the valve can be opened and closed. The drive section includes a cylinder, piston and rod, and the disk section is attached to a forward end of the rod. The structure of the disk section is the same as that of a diaphragm having a film round the disk section and also having an annular protrusion at the center. The annular protrusion is interposed between the main body and the cylinder. Due to the above structure, fluid is prevented from flowing outside and also fluid is prevented from being contaminated with dust when the valve is opened and closed. A bellows can be used instead of a diaphragm.
SUMMARY OF THE INVENTION
However, the above conventional automatic valve is disadvantageous as described below. The profile of the flowing path of the conventional automatic valve is complicated, and further the flowing direction of fluid is suddenly changed, which causes a great pressure loss. Therefore, when it is necessary to provide an automatic valve with a high flow rate, the structure of the above conventional automatic valve is not appropriate for practical use. Further, when it is used for carrying fluid containing slurry, abrasion tends to be caused at the valve seat section, and the sealing performance is deteriorated. Furthermore, according to the structure of the conventional automatic valve, the valve body and the drive section are composed separately from each other. Therefore, the size of the entire valve is increased, and a large space is required for installation. In the drive section, there are provided two sliding sections. Accordingly, resistance is increased in the case of operation of the valve, and it is difficult to instantly transmit the pressure of fluid to the sealing section.
The present invention has been accomplished to solve the above problems of the conventional automatic valve. It is an object of the present invention to provide a compact automatic valve characterized in that: the pressure loss of fluid is low; the flow rate characteristic is so excellent that it can be used for chemicals containing slurry; and the sealing performance is high.
According to the present invention, there is provided an automatic valve comprising: a cylindrical body; a sleeve inserted into the cylindrical body so that the sleeve can be moved in the cylindrical body in the axial direction; a first diaphragm having an annular joint section joined to one end of the sleeve and also having an annular protrusion arranged in the outer circumferential section; a second diaphragm having an annular joint section joined to the other end of the sleeve and also having an annular protrusion arranged in the outer circumferential section; a first cylindrical diaphragm presser for pressing the annular protrusion of one diaphragm, the first cylindrical diaphragm presser being joined to one end of the cylindrical body, the first cylindrical diaphragm presser having a fluid communicating port; a second cylindrical diaphragm presser for pressing the annular protrusion of the other diaphragm, the second cylindrical diaphragm presser being joined to the other end of the cylindrical body, a valve member, which is contacted with and separated from the lower end of the sleeve, being arranged at the center of the bottom of the second cylindrical diaphragm presser, the second cylindrical diaphragm presser having a fluid communicating port; and a pair of fluid supply ports respectively communicating with an upper and a lower clearance formed by the cylindrical body, diaphragms and sleeve.
According to a preferred embodiment of the present invention, one of the first and the second diaphragm is integrated with the sleeve.
According to another preferred embodiment of the present invention, both the first and the second diaphragm are integrated with the sleeve.
According to still another preferred embodiment of the present invention, the fluid communicating ports of the first and the second diaphragm presser are formed on the sides of the respective diaphragm pressers.
The structure of the automatic valve of the present invention is described above. When the automatic valve of the present invention is used, the following excellent effects can be provided.
The sleeve, which is a sealing member, and the diaphragms, which receive the pressure of fluid, are directly joined to each other or integrally formed with each other, and further only one sliding section is used. Therefore, the loss in the transmission of force is small when the valve is operated. Accordingly, the valve can be operated stably and positively, and it is possible to obtain a high sealing performance.
The profile of the flowing path of fluid is simple. Therefore, the flowing direction of fluid is not greatly changed, and it is possible to obtain an excellent flow rate characteristic. Therefore, even when the valve is used for chemicals containing slurry, abrasion is seldom caused in the sealing section. Accordingly, the sealing property can be maintained high over a long period of time.
The automatic valve body and the drive section of the valve are composed integrally with each other. Therefore, the number of parts is small, that is, the valve can be compact.
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patent: 5139225 (1992-08-01), Olsen et al.
patent: 5657786 (1997-08-01), DuRoss et al.
patent: 5979502 (1999-11-01), Scott et al.
Asahi Organic Chemicals Industry Co. Ltd.
Burns Doane Swecker & Mathis L.L.P.
Keasel Eric
Shaver Kevin
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