GB2171779A

GB2171779A - Check valve

Info

Publication number: GB2171779A
Application number: GB08505427A
Authority: GB
Inventors: Brian Patrick Neal; Paul Anthony Fisher
Original assignee: Bendix Ltd
Current assignee: Honeywell UK Ltd
Priority date: 1985-03-02
Filing date: 1985-03-02
Publication date: 1986-09-03
Also published as: GB8505427D0

Abstract

A check valve is constructed with a valve member 8 urged via a spring 12 against an hemispherical seat 6 surrounding an input port 2 of a valve body, the spring being retained by a moulded plastics spider 13 slidable on a guide stem 10 and having radially resilient legs 11 which can be compressed to permit the member 13, together with parts 8 and 12, to be assembled through the output port 3, the legs 11 thereafter snap engaging with an internal annular shoulder 7 of the valve body. <IMAGE>

Description

SPECIFICATION Fluid system components This invention relates to fluid system components and relates especially but not exclusively to an in-line fluid check valve device.

It has hitherto been normal practice to construct in-line check valves with two body parts each having a fluid port, the body parts being screwed one into the other after insertion of a valve seat, a valve member a suitable biassing spring and possibly a suitable guide or cage element. A typical such in-line check valve is illustrated in Applicants Technical Pamphlet No. 10/005.

According to the present invention there is provided a fluid system component comprising a body having an input port and an output port, at least one active member and snap-in retaining and guide means therefore dimensioned for assembly through one of said parts.

In the case of said component being a check valve the active means may comprise a valve member, the retaining means may be a retaining member separate therefrom and arranged when positioned through said one port to retain a spring for urging the valve member against a seat surrounding the inner end of the other said port.

Said retaining member may be moulded from plastics material.

In order that the invention may be more clearly understood and readily carried into effect the same will be further described by way of example with reference to the accompanying drawing of which, Figure 1 illustrates a sectional view of an inline check valve, Figure 2 shows a sectional view of a further or alternative in-line check valve and, Figure 3 shows an alternative form of moulded plastics retaining means for use in such a check valve.

Referring to the drawing, the check valve comprises a cast and machined steel or aluminium body 1 having an input port 2 and an output port 3. The input port is formed with an external male screw thread at 4 and the output port is provided with an internal female thread 5 for connection to suitable pipe connectors or the like. The interior of the body is generally cylindrical being machined to provide a generally hemispherical seating surface 6 around the inner end of the input port and to provide an inwardly projecting annular shoulder 7 inward of the outlet port. A flat cylindrical valve member 8 which has a diameter somewhat larger than the input port but appreciably less than the inner cylindrical surface 9 of the body is provided with an axial guide stem 10 slideable in an axial guide bore of a moulded plastics three legged "spider" 13.The three legs such as 11 are sufficiently resilient to permit the valve member 8, a captive bias spring 12 and the spider 13 to be assembled into the housing following which the legs 11 snap towards the bore 9 to be retained by the shoulder 7.

The check valve is thus constructed easily and speedily using relatively fewer parts than hitherto. Furthermore, the hemispherical seating surface 6 together with the design of the spider 13 permit beneficial flow characteristics which make this design particularly attractive for use in pressed air reservoir charging systems or the like where high air flow rates are required.

If it is required to reduce the overall length of the check valve as shown in Fig. 1 the retaining means may be provided with legs 21 having a folder back configuration as shown in Fig. 2. By such a design a similar degree of flexibility of the legs may be provided within a shorter length of the inner cylindrical bore 29.

The valve is assembled through the outlet port 23 similarly to the valve component of Fig. 1.

The various components of a check valve according to the invention may be formed of any suitably chosen material. For example, the valve member 6 and spider 13 of Fig. 1 or the retaining means of Fig. 2 may be made of suitable metal or moulded plastics. Indeed although for compressed air applications the body 1 may preferably be made of machined metal for some applications such a body may be made of nylon or other synthetic material suitable to the use.

A further form of a moulded plastics retaining means which could be used as an alternative to the above or the spider 13 of Fig. 1 or the spider 23 of Fig. 2 is shown on an enlarged scale in Fig. 3. The central boss 31 has an axial bore 32 to slidingly receive the guide stem such as 10 (Fig. 1) of the valve element the outward spreading resilient curved arms 33 are arranged to have a free outer diametral measurement sufficiently greater than this inner diameter of the retaining shoulder 7.

The valve is then assembled by threadedly feeding the retaining member together with the spring and valve member along the thread of the output port.

1. A fluid system component comprising a body having an input port an output port at least one active member and snap-in retaining and guide means therefor.

2. A fluid system component as claimed in claim 1 the active means being a check valve member the retaining means being a retaining member separate therefrom and arranged when positioned through said one port to retain a spring for urging the valve member against a seat surrounding the inner end of the other port.

3. A fluid system component as claimed in claim 2 the seat being formed by a part

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Fluid system components This invention relates to fluid system components and relates especially but not exclusively to an in-line fluid check valve device. It has hitherto been normal practice to construct in-line check valves with two body parts each having a fluid port, the body parts being screwed one into the other after insertion of a valve seat, a valve member a suitable biassing spring and possibly a suitable guide or cage element. A typical such in-line check valve is illustrated in Applicants Technical Pamphlet No. 10/005. According to the present invention there is provided a fluid system component comprising a body having an input port and an output port, at least one active member and snap-in retaining and guide means therefore dimensioned for assembly through one of said parts. In the case of said component being a check valve the active means may comprise a valve member, the retaining means may be a retaining member separate therefrom and arranged when positioned through said one port to retain a spring for urging the valve member against a seat surrounding the inner end of the other said port. Said retaining member may be moulded from plastics material. In order that the invention may be more clearly understood and readily carried into effect the same will be further described by way of example with reference to the accompanying drawing of which, Figure 1 illustrates a sectional view of an inline check valve, Figure 2 shows a sectional view of a further or alternative in-line check valve and, Figure 3 shows an alternative form of moulded plastics retaining means for use in such a check valve. Referring to the drawing, the check valve comprises a cast and machined steel or aluminium body 1 having an input port 2 and an output port 3. The input port is formed with an external male screw thread at 4 and the output port is provided with an internal female thread 5 for connection to suitable pipe connectors or the like. The interior of the body is generally cylindrical being machined to provide a generally hemispherical seating surface 6 around the inner end of the input port and to provide an inwardly projecting annular shoulder 7 inward of the outlet port. A flat cylindrical valve member 8 which has a diameter somewhat larger than the input port but appreciably less than the inner cylindrical surface 9 of the body is provided with an axial guide stem 10 slideable in an axial guide bore of a moulded plastics three legged "spider" 13.The three legs such as 11 are sufficiently resilient to permit the valve member 8, a captive bias spring 12 and the spider 13 to be assembled into the housing following which the legs 11 snap towards the bore 9 to be retained by the shoulder 7. The check valve is thus constructed easily and speedily using relatively fewer parts than hitherto. Furthermore, the hemispherical seating surface 6 together with the design of the spider 13 permit beneficial flow characteristics which make this design particularly attractive for use in pressed air reservoir charging systems or the like where high air flow rates are required. If it is required to reduce the overall length of the check valve as shown in Fig. 1 the retaining means may be provided with legs 21 having a folder back configuration as shown in Fig. 2. By such a design a similar degree of flexibility of the legs may be provided within a shorter length of the inner cylindrical bore 29. The valve is assembled through the outlet port 23 similarly to the valve component of Fig. 1. The various components of a check valve according to the invention may be formed of any suitably chosen material. For example, the valve member 6 and spider 13 of Fig. 1 or the retaining means of Fig. 2 may be made of suitable metal or moulded plastics. Indeed although for compressed air applications the body 1 may preferably be made of machined metal for some applications such a body may be made of nylon or other synthetic material suitable to the use. A further form of a moulded plastics retaining means which could be used as an alternative to the above or the spider 13 of Fig. 1 or the spider 23 of Fig. 2 is shown on an enlarged scale in Fig. 3. The central boss 31 has an axial bore 32 to slidingly receive the guide stem such as 10 (Fig. 1) of the valve element the outward spreading resilient curved arms 33 are arranged to have a free outer diametral measurement sufficiently greater than this inner diameter of the retaining shoulder 7. The valve is then assembled by threadedly feeding the retaining member together with the spring and valve member along the thread of the output port. CLAIMS

3. A fluid system component as claimed in claim 2 the seat being formed by a part spherical or other curved section surface in the body.

4. A fluid system component as claimed in claim 1, 2 or 3 the retaining member comprising a plurality of radially outwardly extending resilient arms or legs which rest against an inwardly porjecting portion of the body.

5. A fluid system component as claimed in claim 2, 3 or 4 the retaining member being formed of moulded plastics.

6. A check valve substantially as described herein with reference to Fig. 1, Fig. 2 or said figures modified to include a retaining member as shown in Fig. 3.