WO1994021352B1

WO1994021352B1 - Automatic fluid flow control and strainer device

Info

Publication number: WO1994021352B1
Application number: PCT/US1994/003012
Authority: WO
Filing date: 1994-03-18
Publication date: 1994-10-27

Abstract

An automatic fluid flow control valve and strainer device (10) which provides a constant flow rate of strained fluid despite varying differential pressures and employs a combination of a unitary body (12) with an integrated, removable strainer assembly (16) and a removable flow control assembly (18). The body (12) is essentially in the shape of a 'Y' and provides a compact valve with minimum threaded joints and access to the various components thereof with minimum disassembly. The removable strainer assembly (16) is configured and arranged in a manner so that fluid flows from the outside to the inside of a cup-shaped strainer (16a), allowing easier use and cleaning.

Claims

AMENDED CLAIMS

[received by the International Bureau on 15 September 1994 (15.09.94); original claims 1-3 and 5 cancelled; original claim 4 amended; new claims 6-9 added (2 pages)]

4. A fluid flow control device having a unitary body comprising a valve assembly comprising a removable flow control valve assembly contained within the body for receiving fluid flow and automatically controlling the fluid flow through said device, a removable strainer contained within the body around the valve assembly for straining fluid which flows through the device before fluid reaches the removable flow control valve assembly, a removable strainer cover for holding said strainer in place adjacent said removable flow control valve assembly, said strainer and said flow control valve assembly being housed within the same chamber, said strainer comprising an elongated cylinder in the shape of a cup with a closed side wall and closed end to encase the exposed inlet portion of said flow control valve assembly, and said strainer being arranged and configured so that fluid flows from the outside to the inside of said strainer prior to flowing through the flow control valve assembly, so that debris is collected on the outside of the closed side wall and closed end of said strainer for easy cleaning.

6. The device of Claim 4 wherein said removable strainer cover comprises integral lugs to frictionally hold said strainer in place against said removable flow ^• control valve assembly.

7. The device of Claim 4 wherein there is a gap between said removable cover and said strainer, to allow fluid to pass through the closed end and sides of said strainer while blocking debris. 13

8. The device of Claim 4 wherein there is a gap between said removable cover and said strainer, to allow fluid to pass through the closed end and sides of said strainer while blocking debris, and a first set of lugs attached to the removable cover to hold the strainer in place along its center axis, and a second set of lugs attached to the removable cover to hold the strainer against said valve assembly so as to provide a seal against debris entering said valve assembly.

9. The device of Claim 4 wherein there is a gap between said removable cover and said strainer, to allow fluid to pass through the closed end and sides of said strainer while blocking debris, and wherein there is a port within said removable strainer cover to allow debris to be expelled without removing said cover.

14

STATEMENT UNDER ARTICLE 19(1)

The specification has been amended to correct a typographical error. Claims 1-3 and 5 have been cancelled, Claim 4 has been amended to meet the requirements of novelty and inventive step, and new Claims 6-9 have been added.

Claims 1-3 were considered not novel or not to involve an inventive step in view of Coulter, U.S. Pat. No. 4,827,974, and Claims 4-5 were considered not to involve an inventive step in view of Coulter when combined with Troy, U.S. Pat. No. 4,451,456.

The present invention is a significant improvement over the device of Coulter. The Coulter device has a flow control valve and a strainer (i.e. "[a] sleeve 66 with numerous perforations 68 therein is welded or otherwise secured between the closure cap 60 and the upstream end 36 of the core sleeve 34") (see page 2, lines 62-64 and FIG. 1). The "strainer" disclosed in Coulter is in the shape of a cylinder with an open end and a closed end that terminates in attachment to the closure cap.

The Coulter device is different in that the "sleeve" is welded, or otherwise attached to the closure cap, so that the cap forms the closed end. Also, Coulter's "sleeve" is positioned between the cap and the valve.

In contrast, the present invention requires a cup-shaped strainer, where the closed end is a part of the strainer (see Claim 4). This novel orientation allows fluid to flow through the closed end and the side wall, rather than only through the side wall. This orientation inherently exposes more of the surface area of the strainer, so that there is less likelihood of clogging, and allows for the use of a blow down port, as discussed further below.

Also, the strainer of the present invention encases the inlet end of the valve. This allows the overall length of the improved device to be lessened, resulting in a reduction in manufacturing costs and installation space.

Another difference is the present device allows removal of the cap without removal of the strainer, so that debris can be removed from the outside surface of the strainer without danger of introducing debris in the valve assembly. In Coulter, when the cap is removed, either the entire cap and strainer assembly is removed, or, at a minimum, at least one end of the valve is exposed allowing debris to enter the valve. In the present device, the cover can be removed and the strainer remains in place until removed by an operator.

Troy does not disclose a specific configuration of a blown down port as in this invention. The use of the blow down port in the present invention is novel and involves an inventive step. The combmation of the strainer cover, the strainer, the space between the cover and the strainer, and the port, as required by claim 9 for example, is not suggested by Coulter in view of Troy.

In view of the foregoing, it is submitted that the application as presently amended defines subject matter which is patentable over the cited art. Accordingly, reconsideration and allowance of the claims as presently amended is requested.