GB2612847A

GB2612847A - Valve Controller

Info

Publication number: GB2612847A
Application number: GB2116494.2A
Authority: GB
Inventors: Sach Martin
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-11-16
Filing date: 2021-11-16
Publication date: 2023-05-17
Also published as: GB202116494D0

Abstract

A valve controller or insert 400 for sealing a valve and comprising a plastic body 410 having front 420 and rear 430 ends and a screw-threaded portion 470 for engaging an interior screw-thread of a valve, the front end comprising a sealing surface 440 for engaging a valve seat, the rear end having a centrally located channel 450 having a polygonal cross section extending part way into the body for receiving a polygonal tool to screw and unscrew the controller, each side of the channel having a slight convex curve. The channel may be hexagonal for receiving a hex or Allen key. A backup polygonal hole of a narrower diameter than the channel may extend into the body from the base of the channel for receiving a polygonal tool. The sides of the backup hole may have a metal lining and a slight convex curve. The body near the rear end may comprise a notch 480 for receiving an o-ring. The sealing surface may be tapered in the shape of a truncated cone whose front face is dome shaped. The slight convex curves in the sides prevent the corners being rounded off by overtightening or repeated use, preventing the controller becoming stuck.

Description

VALVE CONTROLLER

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a valve controller or an insert for creating a seal in a valve, particularly for use in domestic and commercial plumbing and heating systems.

[0002] A valve controller is used to open and close a valve. Many different water and other fluid valves use a valve controller comprising a disc-shaped, rubber washer that is attached to a stem via a central hole. A typical drain valve 100 having a stem 110 and flat rubber washer 120 is illustrated in Figure 1. The stem 110 is screwed into the valve 100 to press the washer 120 flat against a flanged seat 130, blocking an outlet 140 in the valve 100 and preventing the flow of water or other liquid. Flow is permitted by unscrewing the stem 110 so that the washer 120 moves away from the seat 130.

[0003] There are many disadvantages with rubber washers. Over time, the rubber of the washer can degrade in many different ways, compromising the seal between the washer and the seat. For example, the face of the rubber washer can fuse with the seat of the valve. When the stem is later unscrewed, the washer separates from the stem and remains stuck inside the valve body. Rubber can be compressed too much by overtightening of the stem, resulting in a leaking valve. Severe over-compression of the washer can cause inelastic deformation, so the washer stays compressed even when not under load. The rubber can suffer chemical fatigue and become hard and brittle, especially when subjected to alternating hot and cold or to chemicals/minerals in water. Even when new, the size tolerances in both washer and stem manufacture are quite loose so washers may not always fit onto the stem or may not fit securely.

[0004] GB2537611 tackles some of these disadvantages and describes a single-piece, screw-threaded insert for a drain valve, illustrated in Figure 2. The insert 150 is integrally formed from a plastics material that does not degrade over time, like typical rubber washers, or rust, like the metal components of typical stems.

[0005] The front end of the insert 150 has a tapered sealing surface which engages with the drain valve seat 130. This provides an improved fluid-tight seal between the insert 150 and the seat 130. Nevertheless, it would be beneficial if the quality of the seal could be improved even further. The rear of the insert is provided with an opening for receiving a hex key 160. This is vulnerable to failure, with the opening becoming rounded off, if the insert is over-tightened or becomes stuck.

SUMMARY OF THE INVENTION

[0006] The present invention provides a valve controller for use in sealing a valve, the valve controller comprising a body formed from a plastics material, the body having a front end, a rear end and a central axis extending between the front and rear ends; the body having a screw-threaded portion for engaging with an interior screw-thread of a valve in use; the front end comprising a sealing surface for engaging with a valve seat to seal the valve in use; the rear end having a centrally located channel extending part way into the body along the axis, the channel having a substantially polygonal cross-section in a plane perpendicular to the axis, each side of the channel having a convex curve.

[0007] Embodiments of the invention reduce the problem of the corners in a polygonal channel becoming rounded off by providing a convex curve to each side wall of the channel. Each convex curve is only slight, so that the channel is still substantially polygonal and can still receive a corresponding polygonal tool (e.g. a hex key fitting a substantially hexagonal channel) that is operable in use to screw and unscrew the valve controller. The convex curves ensure that the turning force is not directed into the corners of the polygonal channel, reducing damage caused by overtightening or regular use.

[0008] Even with the above protective design features, damage to the channel is still possible. Preferably, therefore, a polygonal backup hole of a narrower diameter than the channel extends along the axis further into the body from the base of the channel. This secondary or backup hole receives a correspondingly thinner polygonal tool that is operable in use to screw and unscrew the valve controller even if the main channel has been so damaged that it is no longer usable.

[0009] Preferably there is a step between the channel and the backup hole where the diameter of the channel narrows to transition into the backup hole. By providing a relatively shallow step rather than smoothly transitioning between the main channel and the backup hole, a user is discouraged from forcing a larger diameter tool into the backup hole.

[0010] In another aspect, the present invention provides a valve controller for use in sealing a valve, the valve controller comprising a body formed from a plastics material, the body having a front end, a rear end and a central axis extending between the front and rear ends; the body having a screw-threaded portion for engaging with an interior screw-thread of a valve in use; the front end comprising a sealing surface for engaging with a valve seat to seal the valve in use; the rear end having a centrally located channel extending part way into the body along the axis, the channel having a polygonal cross-section in a plane perpendicular to the axis, and a polygonal backup hole of a narrower diameter than the channel extending along the axis further into the body from a base of the channel.

[0011] In this aspect, a narrower backup hole is provided in the event that the main polygonal channel becomes damaged. A thinner polygonal tool, of a size to fit the backup hole, can then be inserted through the channel and into 10 the backup hole to operate the valve controller.

[0012] In some variations on the above aspects of the present invention, the sides of the main channel and/or the backup hole are provided with a metal lining which advantageously strengthens the hole and prevents the corners of the hole being rounded off through repeated use or overtightening.

[0013] Optionally, the screw-threaded portion of the body is near to the front end and the body near to the rear end is substantially cylindrical and has a notch around its perimeter for retaining an 0-ring in use. In this way, a front portion of the body is devoted to enabling the insert to be screwed in and out of the insert, while the a rear portion of the insert that is adjacent to a bonnet covering the opening to the valve can be provided with an 0-ring. This 0-ring engages with the bonnet when the insert is unscrewed to seal the opening to the valve.

[0014] Optionally, the sealing surface is a tapered sealing surface. Using a tapered profile rather than simply presenting a flat surface to a valve seat, ensures a more effective seal against the valve seat that is less prone to sticking and fusing with the seat over time. In particular, the tapered surface only meets the seat at a circular edge rather than over a wide surface that is prone to sticking.

[0015] Optionally, the tapered sealing surface is in the shape of a truncated cone, the tapering sides of the cone for engaging with the valve seat in use. A front face of the truncated cone is in the shape of a dome. A conical sealing surface is a simple and effective shape for creating a water-tight seal with the valve seat when the valve is closed. The front face of the truncated cone, which does not engage with the seat in use, is preferably in the shape of a smooth low dome to avoid sharp edges.

[0016] Optionally, the body is formed as a single piece of a hard and/or substantially rigid and/or substantially incompressible plastics material such as acetal plastic. Using a hard plastics material rather than soft rubber as in common flat washers means that the insert is more hard wearing and less prone to degradation over time. Using a substantially incompressible plastics material avoids the problems with over-compression or permanent deformation of rubber washers that can compromise the seal.

[0017] If a metal lining is provided, the body of the insert can be moulded as a single piece of plastic around the metal lining. More specifically, a method of manufacturing a valve controller with a metal lining comprises providing a metal core and moulding the body of the valve controller as a single piece around the core such that the core becomes the metal lining on the sides of the channel and/or the backup hole.

[0018] In another aspect, the present invention provides a valve comprising a screw-threaded channel, a seat, and an insert as described above screwable relative to the valve to move the insert within the channel between a first position where the valve is open and a second position where the insert engages with the seat, sealing the valve.

[0019] Preferably, the body of the insert is entirely contained within the channel when the insert is in the second position to prevent accidental damage to the insert.

[0020] Preferably, the valve has a bonnet over an entrance to the screw-threaded channel and the insert has an 0-ring near its rear end, the 0-ring engaging with the bonnet to create a seal when the insert is in the first position. This creates a seal preventing water from escaping the channel in the valve when the valve is opened.

[0021] Preferably, the sealing surface of the insert is a tapered sealing surface which engages with an edge of the seat to seal the valve when the insert is in the second position and further extends past the edge.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Preferred embodiments of the invention plus other arrangements or examples to aid understanding, but not necessarily falling within the scope of the claims, are described with reference to the accompanying drawings, in which: [0023] Figure 1 is a cut-away view of a known drain valve having a screw-threaded stem and a flat rubber washer; [0024] Figure 2 is a cut-away view of known drain valve having a screw-threaded, single-piece insert; [0025] Figure 3 is a cut-away view of a drain valve having an improved insert; [0026] Figure 4 is a perspective view of a first improved insert having a metal lining within a polygonal screw hole; and [0027] Figure 5 is a cross-sectional view through the improved insert of Figure 4; [0028] Figure 6 is a perspective view of a second improved insert having a substantially polygonal screw hole with curved edges; [0029] Figure 7 is another perspective view of the improved insert of Figure 6; [0030] Figure 8 is a perspective cutaway view illustrating an improved insert having a backup screw hole; and [0031] Figure 9 is a cross-sectional view through an improved insert having a backup screw hole.

DETAILED DESCRIPTION OF THE INVENTION

[0032] Figure 3 illustrates a valve controller or insert 200 in use within a drain valve 100. The suggested use in a drain valve 100 is just one example for ease of illustration. In general, the insert 200 is extremely versatile and can be used in many different types of valve to replace or retrofit the common stem 110 and washer 120 arrangement illustrated in Figure 1. The insert 200 also provides several improvements over the insert 150 depicted in Figure 2 and described in GB2537611.

[0033] In Figure 3, the near side of the drain valve 100 has been cut away and the cap or bonnet 170 (see Figure 1) has been removed to better show the insert 200 in place within the drain valve 100. In use, the insert 200 is screwed into an opening 180 that opens into a screw-threaded channel inside the valve 100. This channel normally receives a stem 110. When fully screwed into the valve 100, the insert 200 engages with the seat 130, closing the valve 100 and preventing water (or another fluid) from passing from the valve inlet 190 to the outlet 140.

[0034] Unscrewing the insert 200 moves it away from the seat 130 to open the valve 130, permitting water to pass from the inlet 190 to the outlet 140. Water may also move around the insert 200 and escape the valve 100 through the opening 180. This is undesirable. In the common stem 110 arrangement of Figure 1, 0-rings or other gaskets are used to create a seal between the stem 110 and the bonnet 170 to prevent water escaping through the opening. In the known insert 150 shown in Figure 2, the body of the insert 150 filled a large portion of the channel extending from the opening 180 and acted to seal the opening 180 so that water could not escape. In this arrangement, no 0-ring was necessary. However, due to variation in manufacturing tolerances for the diameter of the channel inside the valve 100, this seal occasionally failed permitting water to escape through the opening when the valve was opened.

[0035] There are also manufacturing tolerances in the diameter of the hole defined by the valve seat 130, sometimes as much as 2mm between different valves. The tapering sealing surface of the known insert 150 of Figure 25 2 is able to cope with a range of valve seat 130 sizes but sometimes failed to create an effective seal in the most extreme cases.

[0036] The inserts described below address these problems and offer further advantages over known inserts and washer arrangements.

[0037] Figure 4 is a perspective view of a first insert 300 from the rear end. Figure 5 is a cross-sectional view through the centre of the insert 300 to reveal the interior structure.

[0038] The insert 300 comprises a body 310 having a front end 320 and a rear end 330. The body 310 is substantially rotationally symmetric about a central axis extending between the front end 320 and rear end 330.

[0039] The body 310 is formed as a single piece from a substantially rigid, substantially incompressible, hard plastics material. Using a hard plastics material rather than soft rubber as in common flat washers 120 means that the inert 300 is less prone to degradation and fusing to the valve 100 over time. Suitable plastics materials include polybutylene, acetal plastic or polyoxymethylene.

[0040] The front end 320 of the insert 300 comprises a tapered sealing surface 340 for engaging with a seat 130 in order to seal a valve 100. Various shapes for the sealing surface 340 are possible. The sealing surface 340 can be substantially frustoconical, with the diameter of the sealing surface 340 reducing linearly towards the front end 320 at an angle of approximately 30° to the axis of the body 310. Spherical surfaces or any curving dome shape are also possible. The sealing surface 340 may end at a sharp point but preferably the sealing surface 340 is truncated leaving either a flat or domed front face, or by providing some other discontinuity to steepen the curvature of the sealing surface 340 to form the face of the front end 320.

[0041] In use, the sealing surface 340 of the insert 300 engages with the seat 130 of the valve 100 to seal it. The sealing surface 340 is therefore truncated only once its diameter is less than the diameter of the aperture in the seat 130, to within all reasonable manufacturing tolerances for a minimum aperture diameter. Consequently, the exact shape of the very front face does not affect the sealing operation of the insert 300 and can be chosen to simplify manufacture, improve structural strength, or even for aesthetic reasons. For example, the smooth dome for the front face shown in Figures 3 to 5 avoids sharp edges which might weaken the structure of the insert 300.

[0042] To ensure that reasonable manufacturing tolerances for a maximum diameter of the aperture in the seat 130 are accounted for, the maximum diameter of the sealing surface 340 is the same as the maximum diameter of the body 310 near the front end 320 and tapers linearly from that maximum diameter. In the known insert 150 of Figure 2, there is a substantially flat shelf or discontinuity in the diameter of the insert between the body and the sealing surface meaning that valves with an exceptionally large seat 130 aperture diameter were not properly sealed. Additionally, with a similar angle of taper but starting from a wider diameter, the sealing surface 340 of the improved insert 300 is longer than in the known insert 150. The improved insert 300 consequently handles manufacturing tolerances in the distance that the internal screw-thread of the valve 100 extends into the valve's channel and the sealing surface 340 will reach the valve seat 130 even if the internal screw-thread stops unusually early.

[0043] The rear end 330 of the insert 300 is provided with a centrally located polygonal hole or channel 350. The hole 350 extends part of the way into the body 310 along the central axis of the insert 300. The polygonal hole 350 extends far enough into the body 310 to securely accommodate a corresponding polygonal key in order to screw or unscrew the insert 300 in the valve 100. The hole 350 may be hexagonal for receiving a hex (or Allen) key or other polygonal shapes may be used such as a square hole and a corresponding square (or Robertson) drive, for example.

[0044] The sides of the hole 350 have a metal lining 360 to strengthen the hole 350 and to prevent the corners being rounded off by overtightening or repeated screwing and unscrewing of the insert 300. When manufacturing the insert 300, the metal lining 360 may be provided as a core or substrate and the plastic body 310 is overmoulded around it.

[0045] Near to the front end 320, the body 310 has a screw-threaded portion 370 for engaging with an internal screw-thread of the valve 100. The cross-sectional diameter of the screw-threaded portion is substantially the same as the interior diameter of the channel in the valve 100. The cross-sectional diameter of the body 310 reduces from the screw-threaded portion 370 to the front end 320 to define the sealing surface 340.

[0046] Near to the rear end 320, the body 310 is substantially cylindrical is cross-section and has a diameter less than the interior diameter of the channel in the valve 100. More specifically, the diameter of the rear end 320 of the body 310 is slightly less than the diameter of a hole in the valve bonnet 170 so that the rear end 320 of the insert 300 can protrude through the bonnet 170 when it is unscrewed. Advantageously, the insert 300 is entirely contained within the valve 100 when the insert 300 is fully screwed in and the valve 100 closed. This is more aesthetically pleasing and prevents accidental knocking of or damage to the insert 300.

[0047] The substantially cylindrical portion near the rear end 320 of the body 310 has a notch 380 around its perimeter. As illustrated in Figure 5, the notch 380 is for retaining an 0-ring 390. The 0-ring can be slipped over the rear end 330 of the body 310 and into the notch 380 prior to screwing the insert 300 into the valve 100. Alternatively, the body 310 may be moulded with an 0-ring shape or bulge so that an additional 0-ring 390 is not required.

[0048] The length of the insert 300 is such that the 0-ring 390 (or bulge) engages with the bonnet 170 of the valve 100 when the insert 300 is unscrewed to open the valve 100. This prevents water escaping through the opening 180 in the valve 100. To account for manufacturing tolerances in the size of the opening in the bonnet 170, the 0-ring is more compressible and more resilient than typical 0-rings so that it adjusts to and fills a wider range of bonnets 170 than a typical 0-ring.

[0049] Figure 6 is a perspective view of a second improved insert 400.

Figure 7 shows the insert 400 from the rear end, looking down a hole 450 in the insert 400 to better illustrate the unique shape of the hole 450.

[0050] The second insert 400 of Figures 6 and 7 shares many of the same features and advantages as the first insert of Figures 4 and 5. In particular, the second insert 400 comprises a body 410 having a front end 420 and a rear end 430. The body 410 is substantially rotationally symmetric about a central axis extending between the front end 420 and rear end 430. The body 410 is formed as a single piece from a substantially rigid, substantially incompressible, hard plastics material.

[0051] The front end 420 of the second insert 400 comprises a tapered sealing surface 440 for engaging with a seat 130 in order to seal a valve 100. As discussed above, various shapes for the sealing surface 440 are possible.

[0052] The rear end 430 of the second insert 400 is provided with a centrally located substantially polygonal hole or channel 450. The hole 450 is similar to the hole 350 in the first insert 300 of Figures 4 and 5, and the above description of the different design considerations and options for that hole 350 also applies to the hole 450 of the second insert 400. However, the walls of the hole 350 in the first insert 300 are straight, forming a regular, straight-edged polygon. The walls of the hole 450 in the second insert 400 are curved inwardly, as best illustrated in Figure 7. The curving side walls of the hole 450 protect the hole 450 and, in particular, the corners of the hole 450 from damage. Consequently, the hole 450 of the second insert 400 does not require a metal lining 360. This simplifies manufacture compared to the first insert 300.

[0053] More specifically, each side wall of the hole 450 in the second insert 400 is a smooth convex curve, the centre of each wall protruding further into the hole than a flat face would. The amount of curvature is small so that a standard polygonal head, such as a standard Allen key (for a hexagonal hole) or a Robertson drive (for a square hole), still fits within the hole 450.

Nevertheless, the protruding walls ensure that a turning force applied to a polygonal head is directed against a side wall rather than into the corners of the hole 450. This protects the corners of the hole 450 from being rounded off by overtightening or repeated screwing and unscrewing.

[0054] Near to the front end 420 of the insert 400, the body 410 has a screw-threaded portion 470 for engaging with an internal screw-thread of the valve 100. Near to the rear end 420, the body 410 is substantially cylindrical in cross-section and has a diameter less than the interior diameter of the channel in the valve 100. The substantially cylindrical portion near the rear end 420 of the body 410 has a notch 480 around its perimeter for retaining an 0-ring. The design considerations of all these features are again similar to those discussed above in relation to the first insert 300.

[0055] Even with a metal lining 360 or curved side walls, the hole 350, 450 in the first insert 300 or second insert 400 can become damaged over time or with use of excessive force. Figures 8 and 9 illustrate an insert 500 having a main hole or channel 505. The main channel 505 is similar to the hole 350, 450 provided in either the first insert 300 or the second insert 400. The insert 500 also includes a backup hole or channel 515. Such a backup hole 515 can be incorporated into either the first insert 300 or the second insert 400 by adding the backup hole 505 to the end of either insert's hole 350, 450.

[0056] The backup hole 515 is a straight continuation of the main channel 505 extending further into the body of the insert 500, having the same polygonal shape, but with a smaller diameter. A step 525 at the base of the main channel 505 defines a transition between the main channel 505 and the backup hole 515 where the diameter of the channel 505 is reduced. The walls of the backup hole 515 can be straight (as with the walls of the hole 350 in the first insert 300) or convex (as with the walls of the hole 450 in the second insert 400) as desired. The backup hole 515 can also be provided with a reinforcing metal lining if desired.

[0057] The smaller diameter of the backup hole 515 means that a polygonal tool that fits into the main channel 505, and that can be used to screw or unscrew the insert 500, does not fit into the backup hole 515. Consequently, even if the main channel 505 is damaged while screwing in the insert 500, the backup hole 515 remains undamaged and a smaller diameter tool can be inserted through the main channel 505, fits into the backup hole 515, and is operable to unscrew the insert 500. The step 525 provides a base at the end of the main channel 505 to discourage a user from forcing a large diameter tool into the backup hole 515.

Claims

CLAIMS: 1. A valve controller for use in sealing a valve, the valve controller comprising a body formed from a plastics material, the body having a front end, a rear end and a central axis extending between the front and rear ends; the body having a screw-threaded portion for engaging with an interior screw-thread of a valve in use; the front end comprising a sealing surface for engaging with a valve seat to seal the valve in use; the rear end having a centrally located channel extending part way into the body along the axis, the channel having a substantially polygonal cross-section in a plane perpendicular to the axis, each side of the channel having a slight convex curve, the channel for receiving a corresponding polygonal tool operable in use to screw and unscrew the valve controller.
2. The valve controller of claim 1 wherein the channel has a substantially hexagonal cross-section suitable for receiving a hex key.
3. The valve controller of any preceding claim wherein a polygonal backup hole of a narrower diameter than the channel extends along the axis further into the body from the base of the channel, the backup hole for receiving a corresponding polygonal tool operable in use to screw and unscrew the valve controller.
4. The valve controller of claim 3 further comprising a step between the channel and the backup hole where the diameter of the channel narrows to transition into the backup hole.
5. The valve controller of claim 3 or claim 4 wherein the sides of the backup hole have a metal lining.
6. The valve controller of any of claims 3 to 5 wherein each side of the backup hole has a slight convex curve.
7. The valve controller of any preceding claim wherein the body near to the rear end is substantially cylindrical and has a notch circling its perimeter for receiving and retaining an 0-ring.
8. The valve controller of any preceding claim wherein the sealing surface is a tapered sealing surface.
9. The valve controller of claim 8 wherein the tapered sealing surface is in the shape of a truncated cone.
10. The valve controller of claim 9 wherein a front face of the truncated cone is in the shape of a dome.
11. The valve controller of any preceding claim wherein the body is formed as a single piece of a substantially rigid, substantially incompressible plastics material.
12. A valve controller for use in sealing a valve, the valve controller comprising a body formed from a plastics material, the body having a front end, a rear end and a central axis extending between the front and rear ends, the body having a screw-threaded portion for engaging with an interior screw-thread of a valve in use; the front end comprising a sealing surface for engaging with a valve seat to seal the valve in use; the rear end having a centrally located channel extending part way into the body along the axis, the channel having a polygonal cross-section in a plane perpendicular to the axis, and a polygonal backup hole of a narrower diameter than the channel extending along the axis further into the body from a base of the channel.
13. The valve controller of claim 12 wherein the channel and the backup hole have substantially hexagonal cross-sections.
14. The valve controller of claim 12 or 13 further comprising a step between the channel and the backup hole where the diameter of the channel narrows to transition into the backup hole.
15. A valve comprising a screw-threaded channel, a seat, and a valve controller screwable relative to the valve to move the valve controller within the channel between a first position where the valve is open and a second position where the valve controller engages with the seat, closing the valve, the valve controller comprising the valve controller of any preceding claim.