GB1592613A

GB1592613A - Relief valve

Info

Publication number: GB1592613A
Application number: GB9658/77A
Authority: GB
Original assignee: Lucas Industries Ltd
Current assignee: ZF International UK Ltd
Priority date: 1978-04-17
Filing date: 1978-04-17
Publication date: 1981-07-08

Description

(54) RELIEF VALVE (71) We, LUCAS INDUSTRIES LIMITED, a British Company of Great King Street, Birmingham B 19 2XF, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a relief valve which is especially (but not exclusively) intended for use in conjunction with a filter employed in the lubricating system of an internal combustion engine. It is well-known in such lubricating systems to use a disposable filter element so that such element can be changed when dirty but there is a danger, if the element is not changed soon enough, that the filtering medium will become clogged to an extend which will seriously impair the flow of filtered lubricating fluid to the engine bearings and thus cause damage thereto.

Consequently, it is desirable that a relief valve be provided in association with the filter element so that in the event that blockage or partial blockage of the filter element does occur then the relief valve will open to by-pass the filter element and permit a free flow of lubricating fluid, albeit unfiltered fluid, through the engine.

The object of the present invention is to provide an improved form of relief valve.

In accordance with the invention there is provided a relief valve which comprises an annular valve body having a valve seat and port means extending through said seat, a spring locating member which is mounted in said annular valve body so as to project axially therefrom, an annular valve member which is slidable on the exterior of said spring locating member and a coiled compression spring which is located at one end by resilient finger portions provided on the spring locating member and which at its other end acts upon the annular valve member to urge it into engagement with said seat to close said port means.

Preferably, said spring locating member is formed of a resilient plastics material and conveniently there are three finger portions which form an integral part of the spring locating member.

The invention will now be more particularly described with reference to the accompanying drawing wherein Figure 1 is a longitudinal sectional view of one half of one example of a relief valve constructed in accordance with the invention, a part of an associated filter element also being shown, Figure 2 is a perspective view of the spring locating member seen in Figure 1, Figure 3 is a perspective view showing the valve body seen in Figure 1, and Figure 4 is a longitudinal sectional view of one half of another example of a relief valve in accordance with the invention.

Referring now to the drawings the relief valve shown therein is intended for use with a disposable filter element that is to be incorporated in the lubricating system of an internal combustion engine although it is to be understood that a relief valve constructed in accordance with the present invention could. be used in other applications if desired.

In the example shown in Figures 1-3 of the drawings the relief valve comprises an annular valve body 10 which is shown in a longitudinal half section in Figure 1 and in perspective view in Figure 3. Said body 10 is conveniently moulded from a plastics material and includes a central sleeve-like portion 11 which is formed at one axial end of its interior surface with three inwardly directed projections indicated by reference numeral 12 so that three gaps or slots indicated by reference numeral 13 will be formed between said projections 12. The valve body 10 also includes a flange portion 14 which is integrally connected to the exterior of said sleeve-like portion 11 and the exterior of said flange portion 14 is recessed to receive the inner periphery of an annular rubber grommet 15 which is shown in Figure 1. Around the periphery of the valve body and between said flange portion 14 and the sleeve-like portion 11 is formed a plurality of slots 16 which provide port means extending through the valve body and the lower axial ends of said slots 16 are interconnected by a groove 17 (see Figure 1). Futhermore the lower axial end face of said sleeve-like portion 11 and said flange portion 14 form a valve seat indicated in Figure 1 by reference numeral 18.

The relief valve also includes a valve member in the form of a valve plate 19 which is provided on its upper face with a resilient sealing ring 20a adapted to engage the aforesaid valve seat 18 and said valve member 19 is normally urged towards said seat to close said port means 16 by a coiled compression spring 20, one end of said spring bearing on the underside of said valve member 19.

The relief valve also includes a spring locating member indicated generally by reference numeral 21 and seen in perspective form in Figure 2. Said spring locating member is formed from a resilient material such as a resilient plastics material and is conveniently moulded so that it includes a ring portion 22 which is integrally connected to a plurality of resilient finger portions 23. Thus in the example shown in the drawings there are three finger portions which are each integrally formed at their lower ends with an outwardly directed hook portion 24. In assembling the spring locating member 21 to the valve body lIthe resilient finger portions 23 are squeezed together and inserted into the upper end of the valve body 11 as seen in Figure 1 so that said finger portions will pass through the sleeve-like portion 11 and extend between the aforesaid gaps 13 between the projections 12. In this position the ring portion 22 of the spring locating member 21 will be located upon the upper surfaces of said projections 12. The coiled compression spring 20 can then be assembled by pushing it upwardly over the finger portions 23 until the lower end of said spring engages the upper sides of said hook portions 24 as shown in Figure 1 and in this position the finger portions 23 will have sprung outwardly to the position shown in Figure 1 so that the aforesaid spring is located at its upper end by the underside of said valve member 19 (which is slidable on the exterior of said spring locating member 21) and at its lower end by the upper surfaces of said hook portions 24.

Associated with the above described relief valve would be a disposable filter element indicatèd~in Figure 1 by reference numeral 25, such element being of annular cylindrical form and the whole assembly would be completed by an end cap or mounting plate 26 together with a sealing ring 27 which is also of annular form and which is interposed between said mounting plate 26 and the upper end of the sleeve-like portion 11 of the valve body.

In normal use lubricating oil will enter the above-mentioned assembly through ports 28 and will then flow radially outwardly to the exterior of said filter element 25 in the direction of said grommet 15 so that if flows between the upper side of the grommet and the lower side of the mounting plate 26. After passing inwardly through the filter element 25 the filtered oil will pass to the centre of the assembly and will then flow upwardly and outwardly through the sleeve-like portion 11 as indicated by arrow B. If however the filter element 25 becomes blocked to a degree which causes the oil pressure on the inlet side of said filter element to rise to a predetermined value then the valve member 19 will be opened against the force exerted by the spring 2Q so that unfiltered oil will then be able to flow through the port means 16, as indicated' by arrow C, thereby by-passing the filter element and then flowing again upwardly and outwardly through the interior of the sleeve-like portion 11. Thus a sufficient flow of lubricating oil to the engine bearing will be maintained even though the filter element itself becomes blocked to an undesirable degree.

In the alternative embodiment shown in Figure 4, the relief valve is located at the bottom of the filter element 25 instead of at the top as is the case in the construction shown in Figure 1. There is however an annular valve body 29 having an outwardly directed flange 29a which is located beneath the filter element 25, a seal 30 being interposed between the filter element and the flange. The valve body is formed with a series of apertures 31 forming port means, the upper ends of said apertures providing a valve seat against which bears a seal 32 and its associated valve member 33. There is also provided a spring locating member 34 formed of plastics material which in this case has a closed bottom 35 but which again has a plurality of spring locating fingers 36. A flange 37 formed on said member 34 engages the underside of the valve body 29 and a spring 38 located between said flange 37 and a bottom cover or end plate 39 holds the assembly in position against the underside of the filter element 25. A further spring 40 located between the hook portions 41 of said fingers 36 and the upper side of said valve member 33 (which is slidable on the exterior of the spring locating member 34) ordinarily closes the relief valve as shown in Figure 4 but if the filter element 25 becomes blocked then oil flowing down its exterior will pass into said port means 31 and lift the valve member 33 so that it can then pass upwardly, in an unfiltered condition, through the interior of said element as indicated by arrow C.

The spring locating member 34 is assembled to the valve body 29 in a manner similar to that described in connection with the embodiment shown in Figure 1-3.

WHAT WE CLAIM IS: 1. A relief valve comprising an annular

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. end face of said sleeve-like portion 11 and said flange portion 14 form a valve seat indicated in Figure 1 by reference numeral 18. The relief valve also includes a valve member in the form of a valve plate 19 which is provided on its upper face with a resilient sealing ring 20a adapted to engage the aforesaid valve seat 18 and said valve member 19 is normally urged towards said seat to close said port means 16 by a coiled compression spring 20, one end of said spring bearing on the underside of said valve member 19. The relief valve also includes a spring locating member indicated generally by reference numeral 21 and seen in perspective form in Figure 2. Said spring locating member is formed from a resilient material such as a resilient plastics material and is conveniently moulded so that it includes a ring portion 22 which is integrally connected to a plurality of resilient finger portions 23. Thus in the example shown in the drawings there are three finger portions which are each integrally formed at their lower ends with an outwardly directed hook portion 24. In assembling the spring locating member 21 to the valve body lIthe resilient finger portions 23 are squeezed together and inserted into the upper end of the valve body 11 as seen in Figure 1 so that said finger portions will pass through the sleeve-like portion 11 and extend between the aforesaid gaps 13 between the projections 12. In this position the ring portion 22 of the spring locating member 21 will be located upon the upper surfaces of said projections 12. The coiled compression spring 20 can then be assembled by pushing it upwardly over the finger portions 23 until the lower end of said spring engages the upper sides of said hook portions 24 as shown in Figure 1 and in this position the finger portions 23 will have sprung outwardly to the position shown in Figure 1 so that the aforesaid spring is located at its upper end by the underside of said valve member 19 (which is slidable on the exterior of said spring locating member 21) and at its lower end by the upper surfaces of said hook portions 24. Associated with the above described relief valve would be a disposable filter element indicatèd~in Figure 1 by reference numeral 25, such element being of annular cylindrical form and the whole assembly would be completed by an end cap or mounting plate 26 together with a sealing ring 27 which is also of annular form and which is interposed between said mounting plate 26 and the upper end of the sleeve-like portion 11 of the valve body. In normal use lubricating oil will enter the above-mentioned assembly through ports 28 and will then flow radially outwardly to the exterior of said filter element 25 in the direction of said grommet 15 so that if flows between the upper side of the grommet and the lower side of the mounting plate 26. After passing inwardly through the filter element 25 the filtered oil will pass to the centre of the assembly and will then flow upwardly and outwardly through the sleeve-like portion 11 as indicated by arrow B. If however the filter element 25 becomes blocked to a degree which causes the oil pressure on the inlet side of said filter element to rise to a predetermined value then the valve member 19 will be opened against the force exerted by the spring 2Q so that unfiltered oil will then be able to flow through the port means 16, as indicated' by arrow C, thereby by-passing the filter element and then flowing again upwardly and outwardly through the interior of the sleeve-like portion 11. Thus a sufficient flow of lubricating oil to the engine bearing will be maintained even though the filter element itself becomes blocked to an undesirable degree. In the alternative embodiment shown in Figure 4, the relief valve is located at the bottom of the filter element 25 instead of at the top as is the case in the construction shown in Figure 1. There is however an annular valve body 29 having an outwardly directed flange 29a which is located beneath the filter element 25, a seal 30 being interposed between the filter element and the flange. The valve body is formed with a series of apertures 31 forming port means, the upper ends of said apertures providing a valve seat against which bears a seal 32 and its associated valve member 33. There is also provided a spring locating member 34 formed of plastics material which in this case has a closed bottom 35 but which again has a plurality of spring locating fingers 36. A flange 37 formed on said member 34 engages the underside of the valve body 29 and a spring 38 located between said flange 37 and a bottom cover or end plate 39 holds the assembly in position against the underside of the filter element 25. A further spring 40 located between the hook portions 41 of said fingers 36 and the upper side of said valve member 33 (which is slidable on the exterior of the spring locating member 34) ordinarily closes the relief valve as shown in Figure 4 but if the filter element 25 becomes blocked then oil flowing down its exterior will pass into said port means 31 and lift the valve member 33 so that it can then pass upwardly, in an unfiltered condition, through the interior of said element as indicated by arrow C. The spring locating member 34 is assembled to the valve body 29 in a manner similar to that described in connection with the embodiment shown in Figure 1-3. WHAT WE CLAIM IS:

1. A relief valve comprising an annular

valve body having a valve seat and port means extending through said seat, a spring locating member which is mounted in said annular valve body so as to project axially therefrom, an annular member which is slidable on the exterior of said spring locating member and a coiled compression spring which is located at one end by resilient finger portions provided on the spring locating member and which at its other end acts upon the annular valve member to urge it into engagement with said seat to close said port means.

2. A relief valve as claimed in Claim 1 wherein said spring locating member is formed of a resilient plastics material.

3. A relief valve as claimed in Claim 1 or Claim 2 wherein said resilient finger portions form an integral part of said spring locating member.

4. A relief valve as claimed in any one of the preceding claims wherein said valve member is arranged, in use, to engage the in situ underside of said valve seat, said resilient finger portions of the spring locating member extending downwardly below the valve seat.

5. A relief valve as claimed in any one of Claims 1-3 wherein said valve member is arranged, in use, to engage the in situ upper side of said valve seat, said resilient finger portions of the spring locating member extending upwardly above the valve seat.

6. A relief valve as claimed in any one of the preceding claims wherein each of said resilient finger portions is formed at its outer end with an outwardly directed hook portion, said outer ends of the finger portions being adapted to be squeezed from a relatively open and normal position to a position in which said hook portions lie relatively close to each other to permit them to pass through the valve body from one axial end thereof and to permit the coiled compression spring to be pushed over them to a position in which one end of said spring will be engaged and located by the hook portions when the resilient finger portions are permitted to regain their relatively open, normal position.

7. A relief valve substantially as hereinbefore described with reference to and as shown in Figures 1, 2 and 3 or Figure 4 of the accompanying drawings.