GB2168961A - Closure cap - Google Patents
Closure cap Download PDFInfo
- Publication number
- GB2168961A GB2168961A GB08531194A GB8531194A GB2168961A GB 2168961 A GB2168961 A GB 2168961A GB 08531194 A GB08531194 A GB 08531194A GB 8531194 A GB8531194 A GB 8531194A GB 2168961 A GB2168961 A GB 2168961A
- Authority
- GB
- United Kingdom
- Prior art keywords
- closure cap
- shaped member
- container
- opening
- inner cup
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/30—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats
- G01F23/64—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats of the free float type without mechanical transmission elements
- G01F23/72—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats of the free float type without mechanical transmission elements using magnetically actuated indicating means
- G01F23/74—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by floats of the free float type without mechanical transmission elements using magnetically actuated indicating means for sensing changes in level only at discrete points
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Closures For Containers (AREA)
Abstract
A closure cap (1) for closing an opening (2) in a container (3) (for example, the auxiliary container of a sealed cooling system of an internal combustion engine), comprises a pressure relief valve (4), a vacuum relief valve (5) and a liquid level detector (6). The detector comprises a Reed switch (8) actuated by magnets (11) mounted in a float (12). The cap may also comprise inner and outer cup-shaped members linked by a ratchet arrangement constituting torque-limiting means. <IMAGE>
Description
SPECIFICATION
Closure caps
This invention relates to closure caps, and in particular to closure caps adapted to be secured on the filler neck of a vessel subject to changes in internal pressure such as, for example, the radiator of the cooling system of an internal combustion engine.
A closure cap according to the present invention is suitable in particular (though not exclusively) for use in a sealed cooling system for an internal combustion engine in which a pipe leads from the radiator into the bottom part of an auxiliary container so that liquid which escapes from the radiator as the result of expansion of coolant after the radiator has been filled is discharged into the auxiliary container and can be drawn back into the radiator when the liquid cools, the pipe being sealed into the auxiliary container and the latter having an opening closed by a closure cap having a pressure relief valve and a vacuum relief valve therein to prevent damage to the cooling system in the event of excessive pressure or vacuum conditions therein. Such a closure cap is described in the UK Patent Specification No. 1534318.
According to the present invention, a closure cap for closing an opening in a container comprises a pressure relief valve for relieving the pressure in the container when the pressure rises above a first predetermined value, a vacuum relief valve for relieving the pressure in the container when the pressure falls below a second predetermined value, and a liquid level detector for detecting and indicating the level of liquid in the container.
The liquid level detector may indicate the exact level of liquid in the container. Preferably, however, the liquid-level detector indicates when the liquid in the container drops below a predetermined level.
The liquid level detector preferably comprises an electric circuit, at least part of which is positioned inside a fluid tight housing integral with the closure cap. The electric circuit positioned inside the housing preferably comprises a Reed switch and associated electric conductors, the contacts of the switch being moved by at least one magnet positioned on or in a float outside the housing, the float being positioned around the housing and movable relative to the housing, movement of the float being effected by changes in the level of the liquid in the container. The electric circuit preferably includes two blade terminals mounted in the closure cap and connected to the electric circuit in the housing, and two corresponding blade terminal receptacles for connecting the remainder of the electric circuit to the part of the circuit inside the housing.The remainder of the electric circuit preferably includes a warning light or other indicating means; and/or a current detecting circuit. If a low liquid level is detected, or a break in the circuit is detected (no current flow), the warning lamp will light. The electric conductors are preferably enamelled wires, and the blade terminals are preferably welded to the wires.
The pressure relief valve preferably comprises a first plunger which is resiliently biased to close a first aperture in the closure cap. When the pressure inside the container exceeds the first predetermined value the pressure inside the container acts on the first plunger against its resilient biasing to open the first aperture and allow air/liquid to escape from the container. The resilient biasing is preferably provided by a spring. Alternatively, any other suitable pressure relief valve may be used, for example, a resilient diaphragm, or a resiliently mounted flat gasket.
The closure cap preferably also comprises an overflow pipe for allowing the escape of air/liquid from inside the container through the first aperture associated with the pressure relief valve when the pressure inside the container is above the first predetermined value. In this case, the pressure relief valve is preferably positioned in the closure cap such that when the closure cap is fastened to the container to close the opening, the pressure relief valve is above the upper edge of the opening and the entrance to the overflow pipe is preferably positioned next to the first aperture.With this arrangement, the pressure relief valve will always be above the level of liquid in the container, even if the container is full, and after closing of the pressure relief valve no condensed liquid will be left trapped in the closure cap (any condensed liquid will escape through the overflow pipe). This substantially reduces the risk of scalding an operator with condenser liquid if the closure cap is removed by the operator shortly after the pressure relief valve has closed.
The overflow pipe is preferably an integral part of the closure cap. Preferably the exit of the overflow pipe is positioned at the lower edge of the closure cap. This arrangement also substantially reduces the risk of scalding an operator.
The vacuum relief valve preferably comprises a second plunger which is resiliently biased to close a second aperture in the closure cap. When the pressure inside the container falls below the second predetermined value atmospheric pressure outside the container acts on the second plunger against its resilient biasing to open the second aperture and allow air from outside the container to enter the container. The resilient biasing is preferably provided by a spring. Alternatively, any other suitable vacuum relief valve may be used, for example, a resilient diaphragm, or a resiliently mounted flat gasket.
The pressure relief valve is preferably opened when the pressure inside the containers exceeds any value above 160 kPa. The vacuum relief valve is preferably opened when the pressure inside the container falls below 10 kPa.
The closure cap preferably comprises a threaded cap having an internally threaded surface for screw fastening to an externally threaded surface on the opening of the container. Preferably the threaded cap is rotatable independently of the remainder of the closure cap, and the internally threaded surface of the closure cap is substantially continuous, with the overflow pipe (where present) positioned outside the threaded surface. This arrangement increases the mechanical strength between the closure cap and the container over known arrangements.
The closure cap may include torque limiting means for preventing the closure cap from being secured to the opening above a predetermined level -of torque. In this case, preferably the closure cap comprises an outer cup-shaped member, and an inner cup-shaped member arranged concentrically within the outer cup-shaped member, the inner cup-shaped member having a first set of formations thereon for engaging complementary formations on the opening of the container for fastening the closure cap to the container, the inner cup-shaped member also having a second set of formations thereon for engaging co-operating formations on the outer cup-shaped member for providing the torque limiting means.
The first set of formations on the inner cupshaped member and the complementary formations on the opening are preferably screw threads.
Preferably the screw threads on the inner cupshaped member and the opening are substantially continuous. The cross-sectional shape of the thread on the inner cup-shaped member is preferably defined by three edges; a first edge substantially normal to the wall of the member in which the threads are formed; a second edge at an inclined angle to the wall; and a third edge interconnecting the first edge and the second edge, spaced from the wall, and substantially parallel to the wall.
This arrangement reduces the risk of deformation of the threads.
Preferably the second set of formations on the inner cup-shaped member comprises a plurality of outwardly-biased resilient fingers and the co-operating formations on the outer cup-shaped member comprise a plurality of spaced teeth which can be engaged by the free end of each finger, the arrangement being such that rotation of the closure cap to release the closure cap from the opening will cause the free ends of the fingers to latch to the teeth and thereby result in the inner cupshaped member and outer cup-shaped member rotating together, and such that rotation of the closure cap to fasten the closure cap to the opening will cause the free ends to the fingers to frictionally engage the teeth and thereby result in the inner cup-shaped member and outer cup-shaped member rotating together until the level of torque between the inner cup-shaped member and the opening reaches the predetermined level, at which point the frictional engagement breaks down, the inner cup-shaped member stops rotating, but the outer cup-shaped member can continue to rotate independently of the inner cup-shaped member.
Alternatively, the resilient fingers may be the formations on the outer cup-shaped member and the spaced teeth may be the second set of formations on the inner cup-shaped member.
The predetermined level of torque is preferably 4mN.
This invention is further illustrated, by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a partial cross-sectional view of a closure cap in accordance with the invention;
Figure 2 is a cro-ss-sectional view on the line ll-ll in Figure 1;
Figure 3 is a circuit diagram of the liquid level detector of the closure cap;
Figure 4 is a partial cross-sectional view of an alternative closure cap in accordance with the invention;
Figure 5 is a partial cross-section view of a further closure cap in accordance with the invention with the liquid level detected omitted- for clarity;
Figure 6 is a cross-section view on the line VI-VI in Figure 5; and
Figure 7 is an enlarged view of the area label VII in Figure 5.
Referring to the drawings, the closure cap 1 shown is for closing the opening 2 of a container 3 (for example, the auxiliary container of a sealed cooling system for an internal combustion engine).
The closure cap 1 comprises a pressure- relief valve 4, a vacuum relief valve 5, and a liquid level detector 6.
Part of the liquid level detector 6 is mounted inside a fluid-tight housing 7 which is integral with the closure cap 1. The detector 6 comprises a Reed switch 8 which is electrically connected to blade terminals 9 mounted in the cap f by electric conductors (enamelled wires) 10. The Reed switch 8 is actuated by-magnets 11 mounted in a float 12. The float 12 is positioned around the housing 7 and can move in the direction indicated by the arrows relative to the housing, the movement of the float being dependent on the level of liquid in the container 3. Blade terminal receptacles (not shown) are connected to the blade terminals and to the remainder of the electrical circuitry associated with the detector 6, for example, a warning light 30, current detecting means 31 and resistors R1, 2 (see Figure 3).When the liquid in the container 3 is at its required level (Figure 3A), the float 12 engages shoulders 28 on the housing 7 such that the magnets 11 are adjacent the Reed switch 8 and the contacts of the Reed switch are closed causing current to flow through the Reed switch 8 and resistor R1, the current detecting means 31 leaving the warning light to remain unlit. If the liquid level drops below its required level (Figure 3B) the magnets 11 move from their position adjacent the Reed switch 8 to a position below the switch (also as shown in. Figure 2), the contacts of the Reed switch 8 open, current flows through resistors R, and R2, and the current detecting means 31 lights the warning lamp 30. If a break occurs in the circuit, no current flow is detected by the current detecting means 31, and the warning lamp 30 is lit.
The pressure relief valve 4 comprises a first plunger 13 which is biased by spring 14 to close a first aperture 15 in the closure cap 1. The entrance 16 to an overflow pipe 17 is positioned adjacent the first aperture 15, the exit 18 of the overflow pipe being at the bottom edge of the cap 1. The first plunger 13 and spring 14 are secured in posi tion in the closure cap 1 by a spring lock and seal washer 19. The pressure relief valve 4 is positioned above the upper edge 20 of opening 2 to reduce the risk of scalding an operator.
The vacuum relief valve 5 comprises a second plunger 21 which is biased by spring 22 to close a second aperture 23 in the closure cap 1. The second plunger 21 and spring 22 are secured in position by a spring lock washer 24.
The closure cap 1 also comprises a threaded cap 29 comprising an internally threaded surface 25 for screw-threading to an externally threaded surface 26 of-opening 2. The threaded cap 29 can rotate relative to the remainder of the closure cap 1. With the overflow pipe 17 positioned outside the internally threaded surface 25, the latter is substantially continuous. The closure cap 1 also comprises a sealing gasket 27 for making a gas-tight fit with the opening 2.
In an alternative design of closure cap 41 shown in Figure 4, corresponding parts have been given the same reference number. In this arrangement, the closure cap 41 includes torque limiting means 42 as described in more detail below. Further, the pressure relief valve 4 and vacuum relief valve 5 each comprise a flat gasket 43,44 respectively, resiliently held in position by springs 45,46 respectively.
In the further embodiment of closure cap 101 shown in Figure 5, corresponding parts have been given the same reference number. In this case, the liquid level detector has been omitted for clarity.
The closure cap 101 comprises a pressure relief valve 4, a vacuum relief valve 5, torque limiting means 42, an inner cup-shaped member 47, and an outer cup-shaped member 48. The inner cupshaped member 47 has a first set of formations 49 for engaging complementary formations 50 on the opening 2 for fastening the closure cap 101 to the container 3, and a second set of formations 51 for engaging co-operating formations 52 on the outer cup-shaped member 48 for defining the torque limiting means 42.
The first set of formations 49 on the inner cupshaped member 47 comprise a screw thread 53 which engages a corresponding screw thread 54 on the opening 2. The cross-sectional shape of the screw thread 53 on the inner cup-shaped member 47 comprises three edges (see Figure 7); a first edge 55 substantially normal to the wall 56 of the inner cup-shaped member 47, a second edge 57 at an inclined angle to the wall 56, and a third edge 58 connecting the first edge 55 and the second edge 57, spaced from the wall 56 and substantially parallel to the wall 56. This arrangement reduces the risk of deformation of the threads 53.
The second set of formations 51 on the inner cup-shaped member 47 comprises a plurality of outwardly-biased resilient fingers 59, and the cooperating formations 52 on the outer cup-shaped member 48 comprise a plurality of spaced teeth 60 (see Figure 6). The free end 61 of each finger 59 engages the teeth 60. In this arrangement, rotation of the closure cap 101 to release the closure cap from the opening 2 (in the direction X) will cause the free ends 61 of the fingers 59 to latch to the teeth 60 to rotate the inner cup-shaped member 47 and outer cup-shaped member 48 together in the direction X.Rotation of the closure cap 101 to fasten the closure cap to the opening 2 (in the direction Y) will cause the free ends 61 of the fingers 59 to frictionally engage surfaces 62 of the teeth 60 to rotate the inner cup-shaped member 47 and outer cup-shaped member 48 together in the direction Y until the level of torque between the inner cupshaped member 47 and the opening 2 reaches a predetermined leve (that is, when the closure cap
101 is fully fastened to the container 3). At this point, the frictional engagement between the free ends 61 of the fingers 59 and the surfaces 62 of the teeth 60 breaks down, and the inner cup-shaped member 47 stops rotating. The outer cup-shaped member 48 can still rotate in direction Y.
This embodiment of closure cap has the advantage that it prevents the closure cap being overtightened on the container.
Overall, this invention has the advantages that its dimensions are substantially similar to closure caps already available, that it can be fitted to existing containers, and that it can be used to detect and indicate the level of liquid in the container.
Claims (19)
1. A closure cap for closing an opening in a container comprising a pressure relief valve for relieving the pressure in the container when the pressure rises above a first predetermined value, a vacuum relief valve for relieving the pressure in the container when the pressure falls below a second predetermined value, and a liquid level detector for detecting and indicating the level of liquid in the container.
2. A closure cap as claimed in claim 1, wherein the liquid level detector indicates when the liquid in the container drops below a predetermined level.
3. A closure cap as claimed in claim 1 or claim 2, wherein the liquid level detector comprises an electric circuit, at least a part of which is positioned inside a fluid-tight housing integral with the closure cap.
4. A closure cap as claimed in claim 3, wherein the electric circuit positioned inside the housing comprises a Reed switch and associated electric conductors, the contacts of the switch being moved by at least one magnet positioned on or in a float outside the housing, the float being positioned around the housing and movable relative to the housing, movement of the float being effected by changes in the level of the liquid in the container.
5. A closure cap as claimed in claim 3 or claim 4, wherein the electric circuit includes two blade terminals mounted in the closure cap and connected to the electric circuit in the housing, and two corresponding blade terminal receptacles for connecting the remainder of the electric circuit to the part of the circuit in the housing.
6. A closure cap as claimed in claim 5, wherein the remainder of the electric circuit includes a warning light and current detecting means.
7. A closure cap as claimed in any one of the preceding claims, wherein the pressure relief valve comprises a first plunger which is resiliently biased to close a first aperture in the closure cap.
8. A closure cap as claimed in any one of the preceding claims, wherein the closure cap also comprises an overflow pipe for allowing the escape of air/liquid from inside the container through a first aperture associated with the pressure relief valve when the pressure inside the container is above the first predetermined value.
9. A closure cap as claimed in claim 8, wherein the pressure relief valve is positioned in the closure cap such that when the closure cap is fastened to the container to close the opening the pressure relief valve is above the upper edge of the opening and the entrance to the overflow pipe is positioned next to the first aperture.
10. A closure cap as claimed in claim 8 or claim 9, wherein the overflow pipe is an integral part of the closure cap.
11. A closure cap as claimed in claim 10, wherein the exit of the overflow pipe is positioned in the lower edge of the closure cap.
12. A closure cap as claimed in any one of the preceding claims, wherein the vacuum relief valve comprises a second plunger which is resiliently biased to close a second aperture in the closure cap.
13. A closure cap as claimed in any one of the preceding claims, wherein the closure cap comprises atorque limiting means for preventing the closure cap from being secured to the opening above a predetermined level of torque.
14. A closure cap as claimed in claim 13, wherein the closure cap comprises an outer cupshaped member, and an inner cup-shaped member arranged concentrically within the outer cupshaped member, the inner cup-shaped member having a first set of formations for engaging complementary formations on the opening of the container for fastening the closure cap to the container and a second set of formations for engaging cooperating formations on the outer cup-shaped member for providing the torque limiting means.
15. A closure cap as claimed in claim 14, wherein the first set of formations on the inner cup-shaped member and the complementary formations on the opening are screw threads.
16. A closure cap as claimed in claim 15, wherein the screw threads on the inner cup-shaped member and the opening are substantially continuous.
17. A closure cap as claimed in claim 15 or claim 16, wherein the cross-sectional shape of the thread on the inner cup-shaped member is defined by three edges; a first edge substantially normal to the wall of the inner cup-shaped member in which the threads are formed; a second edge at an inclined angle to the wall; and a third edge interconnecting the first and second edges which is spaced from the wall and substantially parallel to the wall.
18. A closure cap as claimed in any one of claims 14 to 17, wherein the second set of formations on the inner cup-shaped member comprises a plurality of outwardly-biased resilient fingers and the co-operating formations on the outer cupshaped member comprise a plurality of spaced teeth which can be engaged by the free end of each finger, the arrangement being such that rotation of the closure cap to release the closure cap from the opening will cause the free ends of the fingers to latch to the teeth and thereby result in the inner cup-shaped member and outer cupshaped member rotating together, and such that rotation of the closure cap to fasten the closure cap to the opening will cause the free ends of the fingers to frictionally engage the teeth and thereby result in the inner cup-shaped member and outer cup-shaped member rotating together until the level of torque between the inner cup-shaped member and the opening reaches the predetermined level, at which point the frictional engagement breaks down, the inner cup-shaped member stops rotating, but the outer cup-shaped member can continue to rotate independently of the inner cup-shaped member.
19. A closure cap substantially as hereinbefore particularly described with reference to and as shown in the accompanying drawings.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB848432594A GB8432594D0 (en) | 1984-12-22 | 1984-12-22 | Closure caps |
| GB848432595A GB8432595D0 (en) | 1984-12-22 | 1984-12-22 | Closure caps |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8531194D0 GB8531194D0 (en) | 1986-01-29 |
| GB2168961A true GB2168961A (en) | 1986-07-02 |
| GB2168961B GB2168961B (en) | 1988-09-28 |
Family
ID=26288613
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08531194A Expired GB2168961B (en) | 1984-12-22 | 1985-12-18 | Closure caps |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2168961B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000001549A1 (en) * | 1998-07-01 | 2000-01-13 | Adwest Köhler Gmbh | Device for monitoring the closed position of a fuel tank cap |
| EP1462776A1 (en) * | 2003-03-24 | 2004-09-29 | Vintec S.r.l | Device for closing barrels |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1087760A (en) * | 1965-09-29 | 1967-10-18 | Gen Motors Corp | Tank closure caps |
| GB1391002A (en) * | 1971-11-02 | 1975-04-16 | Nissan Motor | Motor vehicle radiator incorporating an alarm system for indicating a fall in level of a liquid coolant |
| GB1488781A (en) * | 1975-02-25 | 1977-10-12 | Nisshin Kogyo Kk | Liquid level alarm device |
| GB1527193A (en) * | 1977-01-13 | 1978-10-04 | Bw Controls Inc | Liquid level sensor |
| GB2053477A (en) * | 1979-07-13 | 1981-02-04 | Quintero Alverez F | Apparatus for measurement of liquid levels |
-
1985
- 1985-12-18 GB GB08531194A patent/GB2168961B/en not_active Expired
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1087760A (en) * | 1965-09-29 | 1967-10-18 | Gen Motors Corp | Tank closure caps |
| GB1391002A (en) * | 1971-11-02 | 1975-04-16 | Nissan Motor | Motor vehicle radiator incorporating an alarm system for indicating a fall in level of a liquid coolant |
| GB1488781A (en) * | 1975-02-25 | 1977-10-12 | Nisshin Kogyo Kk | Liquid level alarm device |
| GB1527193A (en) * | 1977-01-13 | 1978-10-04 | Bw Controls Inc | Liquid level sensor |
| GB2053477A (en) * | 1979-07-13 | 1981-02-04 | Quintero Alverez F | Apparatus for measurement of liquid levels |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000001549A1 (en) * | 1998-07-01 | 2000-01-13 | Adwest Köhler Gmbh | Device for monitoring the closed position of a fuel tank cap |
| US6206219B1 (en) | 1998-07-01 | 2001-03-27 | Adwest Kohler Gmbh | Apparatus for monitoring the closed position of a locking gas cap |
| EP1462776A1 (en) * | 2003-03-24 | 2004-09-29 | Vintec S.r.l | Device for closing barrels |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8531194D0 (en) | 1986-01-29 |
| GB2168961B (en) | 1988-09-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |