GB2162690A - Magnetic switch for fluid level monitor - Google Patents
Magnetic switch for fluid level monitor Download PDFInfo
- Publication number
- GB2162690A GB2162690A GB08419728A GB8419728A GB2162690A GB 2162690 A GB2162690 A GB 2162690A GB 08419728 A GB08419728 A GB 08419728A GB 8419728 A GB8419728 A GB 8419728A GB 2162690 A GB2162690 A GB 2162690A
- Authority
- GB
- United Kingdom
- Prior art keywords
- housing
- float
- oil
- fluid
- switch
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H36/00—Switches actuated by change of magnetic field or of electric field, e.g. by change of relative position of magnet and switch, by shielding
- H01H36/02—Switches actuated by change of magnetic field or of electric field, e.g. by change of relative position of magnet and switch, by shielding actuated by movement of a float carrying a magnet
Abstract
A fluid level monitor for use in e.g. the engine oil sump of a car comprises a housing (7) containing a float (14) carrying a magnet 15 that actuates a switch (3) present in a separate body (1) at the top of the housing (7). The magnet and switch can be interchanged. The housing (7) includes a heat actuable snap seal (19) arranged to be actuated when the temperature of the oil has reached its operating temperature so that the level of oil in the housing (7) will stabilise to that of the oil in the sump. <IMAGE>
Description
SPECIFICATION
Fluid level monitor
The invention relates to a fluid level monitor and in particular to one adapted to warn of a sudden loss of fluid from a reservoir. For convenience the invention will be described with particular reference to a monitor for use in warning a driver of a sudden loss of oil from a reservoir in a vehicle e.g. an oil sump, but the invention is applicable in other situations, as will be indicated.
It is one object of the invention to provide a monitor for the purpose specified, adapted to provide a fast response to a loss of fluid and so give a prompt warning.
According to one aspect of the invention there is provided a fluid level monitor comprising a housing to be located in a reservoir of the fluid, the housing containing a float including a magnet and an alarm circuit including a switch actuated by the magnet characterised in that the switch is present in a body at the top of the housing.
Because in the invention the switch is present above the housing and not within it, it is possible to arrange that even a small vertical movement of the float with reference to the single switch will give a prompt alarm signal. Also, the interior of the housing is free of parts required to locate the switch or guide the float relative to the switch; as a result the movement of the float in response to a fall in oil level is more rapid.
Preferably the body for the switch and the housing for the float are separable, for ease of mounting the parts.
The switch may be aby suitable magnetically operable proximity switch, e.g. a reed switch.
In a much preferred feature, the housing includes a sealable port adapted to isolate the oil in the interior of the housing from the body of the oil in the sump until such time as the dynamic oil has reached its operating temperature. For this purpose, the port is sealed by a heat operated snap action seal actuated at the operating temperature of the oil so that when the circulating oil in the sump has reached its operating temperature the seal snaps open to admit that oil into the interior of the housing. In this way, the float undergoes little disturbance and readily assumes the required dynamic level position. The monitor is then arranged to be actuated only when there is an excessive change in the level of oil in the housing.
In the invention just described the magnet is located on the float and the switch is present in a separate body disposed above the float housing. In a modification the magnet is disposed in the body and the switch is mounted on the float with leads extending from the float in such a way as not to obstruct movement of the float.
In order that the invention may be well understood, the invention will now be described with reference to the accompanying diagrammatic drawing, in which is a sectional view of one form of monitor.
The monitor comprises a body 1 which is bolted kto the inside wall of an engine sump, not shown.
The body contains a printed circuit board 2 on
which is mounted a reed switch 3, the contacts 4
of which extend below the board. An earth strip 5
is located on the board 2. One contact 4a extends
towards the adjacent thinned wall portion 6 of the
body which extends at an angle to the horizontal.
A float housing 7 is secured to the underside of
the body 1 such that it extends at an angle of
about 15 to the horizontal so that it will be in the
oil in the sump. The housing is held to the body 1
by abutting the roof 8 of the housing 7 against the
inclined wall 6 of the body 1 with a ledge 9 of the
roof 8 received in a ledge 10 of the body, and a
bolt 11 passed through a flange 12 of the housing
and into the body 1. The flange 12 is struck up
from the housing roof 8 and leaves a hole 13 in the
roof 8 below the contact 4a.
A cylindrical float 14 is present in the housing 7.
A permanent magnet 15 is present at the top of the
float 14 and can be received in the hole 13 in the
roof 8 of the housing, so bringing it towards the
contact 4. The floor 16 of the float is detachable so
that the weight of the float may be adjusted by fill
ing its interior with material of appropriate weight.
The float is free to move unrestrained vertically in
the housing.
The floor 17 of the housing comprises a detacha
ble cap which has inlet ports 18 which are sealed
by a bimetallic snap action sealing disc 19. A hole
20 is present in the sidewall of the housing adja
cent the ledge 9. The printed circuit board 2 is con
nected to an alarm device, e.g. a warning light or
bell, not shown.
In use, the monitor is fitted in a sump. Whilst the
engine is off, oil can enter the housing via the hole
20 to fill the housing to the static level. When the
engine is switched on the sump oil level will fall
due to the circulation of the oil but then will rise
again as the oil temperature increases. Because the
disc 19 seals the ports 18, the float will remain at
the static level until the engine oil reaches its oper
ating temperature when the disc 19 snaps up
wardly so opening the ports 18 and allowing oil to
flow between the sump and the interior of the
housing 7 in order to stabilise the level within the
housing to that of the sump. The float 14 remains
with the magnet 16 of the float at a predetermined
level, below the hole 13, and in proximity to the
reed switch 3.
The monitor is arranged to signal a warning light
or bell when the level of warm oil falls suddenly,
e.g. in the event of a puncture in an oil line. Be
cause the float is free to rise and fall in the hous
ing, the response is fast and accurate.
The monitor of the invention will be used to
monitor the level of any liquid in a reservoir, not
just engine oil. For example, it may be used for the
radiator, the battery cells, and in installations such
as water cisterns, etc.
1. A fluid level monitor comprising a housing
(7) to be located in a reservoir of the fluid, the
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (1)
- **WARNING** start of CLMS field may overlap end of DESC **.SPECIFICATION Fluid level monitor The invention relates to a fluid level monitor and in particular to one adapted to warn of a sudden loss of fluid from a reservoir. For convenience the invention will be described with particular reference to a monitor for use in warning a driver of a sudden loss of oil from a reservoir in a vehicle e.g. an oil sump, but the invention is applicable in other situations, as will be indicated.It is one object of the invention to provide a monitor for the purpose specified, adapted to provide a fast response to a loss of fluid and so give a prompt warning.According to one aspect of the invention there is provided a fluid level monitor comprising a housing to be located in a reservoir of the fluid, the housing containing a float including a magnet and an alarm circuit including a switch actuated by the magnet characterised in that the switch is present in a body at the top of the housing.Because in the invention the switch is present above the housing and not within it, it is possible to arrange that even a small vertical movement of the float with reference to the single switch will give a prompt alarm signal. Also, the interior of the housing is free of parts required to locate the switch or guide the float relative to the switch; as a result the movement of the float in response to a fall in oil level is more rapid.Preferably the body for the switch and the housing for the float are separable, for ease of mounting the parts.The switch may be aby suitable magnetically operable proximity switch, e.g. a reed switch.In a much preferred feature, the housing includes a sealable port adapted to isolate the oil in the interior of the housing from the body of the oil in the sump until such time as the dynamic oil has reached its operating temperature. For this purpose, the port is sealed by a heat operated snap action seal actuated at the operating temperature of the oil so that when the circulating oil in the sump has reached its operating temperature the seal snaps open to admit that oil into the interior of the housing. In this way, the float undergoes little disturbance and readily assumes the required dynamic level position. The monitor is then arranged to be actuated only when there is an excessive change in the level of oil in the housing.In the invention just described the magnet is located on the float and the switch is present in a separate body disposed above the float housing. In a modification the magnet is disposed in the body and the switch is mounted on the float with leads extending from the float in such a way as not to obstruct movement of the float.In order that the invention may be well understood, the invention will now be described with reference to the accompanying diagrammatic drawing, in which is a sectional view of one form of monitor.The monitor comprises a body 1 which is bolted kto the inside wall of an engine sump, not shown.The body contains a printed circuit board 2 on which is mounted a reed switch 3, the contacts 4 of which extend below the board. An earth strip 5 is located on the board 2. One contact 4a extends towards the adjacent thinned wall portion 6 of the body which extends at an angle to the horizontal.A float housing 7 is secured to the underside of the body 1 such that it extends at an angle of about 15 to the horizontal so that it will be in the oil in the sump. The housing is held to the body 1 by abutting the roof 8 of the housing 7 against the inclined wall 6 of the body 1 with a ledge 9 of the roof 8 received in a ledge 10 of the body, and a bolt 11 passed through a flange 12 of the housing and into the body 1. The flange 12 is struck up from the housing roof 8 and leaves a hole 13 in the roof 8 below the contact 4a.A cylindrical float 14 is present in the housing 7.A permanent magnet 15 is present at the top of the float 14 and can be received in the hole 13 in the roof 8 of the housing, so bringing it towards the contact 4. The floor 16 of the float is detachable so that the weight of the float may be adjusted by fill ing its interior with material of appropriate weight.The float is free to move unrestrained vertically in the housing.The floor 17 of the housing comprises a detacha ble cap which has inlet ports 18 which are sealed by a bimetallic snap action sealing disc 19. A hole20 is present in the sidewall of the housing adja cent the ledge 9. The printed circuit board 2 is con nected to an alarm device, e.g. a warning light or bell, not shown.In use, the monitor is fitted in a sump. Whilst the engine is off, oil can enter the housing via the hole20 to fill the housing to the static level. When the engine is switched on the sump oil level will fall due to the circulation of the oil but then will rise again as the oil temperature increases. Because the disc 19 seals the ports 18, the float will remain at the static level until the engine oil reaches its oper ating temperature when the disc 19 snaps up wardly so opening the ports 18 and allowing oil to flow between the sump and the interior of the housing 7 in order to stabilise the level within the housing to that of the sump. The float 14 remains with the magnet 16 of the float at a predetermined level, below the hole 13, and in proximity to the reed switch 3.The monitor is arranged to signal a warning light or bell when the level of warm oil falls suddenly, e.g. in the event of a puncture in an oil line. Be cause the float is free to rise and fall in the hous ing, the response is fast and accurate.The monitor of the invention will be used to monitor the level of any liquid in a reservoir, not just engine oil. For example, it may be used for the radiator, the battery cells, and in installations such as water cisterns, etc.1. A fluid level monitor comprising a housing (7) to be located in a reservoir of the fluid, the housing containing a float (14) including a magnet (15) and and alarm circuit including a switch (3) actuated by the magnet (15) characterised in that the switch (3) is present in a body (1) at the top of the housing (7).2. A monitor according to Claim 1 characterised in that the body (1) and the housing (7) are separable.3. A monitor according to Claim 1 or 2 charac terisedin that the body (1) is secured to the underside of the roof of the reservoir, and the housing (7) is secured to the body (1) such that the housing (7j extends into the fluid at an angle to the horizontal.4. A monitor according to any preceding Claim characterised in that the housing (7) includes a sealable port (18) adapted to isolate the fluid in the interior of the housing (7) from the body of the fluid in the reservoir.5. A monitor according to Claim 4 characterised in that the port (18) is sealed by a heat actuable seal (19) adapted to open to allow fluid from the reservoir to enter the housing (7) when the fluid in the reservoir has reached the temperature sufficient to open the seal (19) to allow fluid from the reservoir to enter the housing (7) and to stabilise the level to that in the reservoir.6. A monitor according to the Claim 4 or 5 characterised in that the floor (17) of the housing (7) includes a detachable cap and the seal (19) is mounted on the cap (17).7. A monitor according to any preceding Claim characterised in that the float (14) is free to move unrestrained in a substantially vertical direction in the housing (7) and carries a permanent magnet (15) at its top face to actuate the switch (3) in the body (1).8. A fluid level monitor substantially as described with reference to the drawing.9. A vehicle including a fluid reservoir such as an engine oil sump or cooling system liquid reservoir characterised in that a fluid level monitor according to any preceding Claim is present in the reservoir.10. An installation including a fluid reservoir such as a water cistern characterised in that a fluid level monitor according to any of Claims to 1 to 8 is present in the reservoir.Amendments to the claims have been filed, and have the following effect: (a) Claims 1, 2, 4 & 7 above have been deleted or textually amended.(b) New or textually amended claims have been filed as follows: (c) Claims 3, 5, 6, 8, 9 & 10 above have been re-numbered as 4, 2, 3, 5, 6 & 7 and their appendancies corrected.1. A fluid level monitor comprising a housing (7) to be located in a reservoir of the fluid, the housing containing a float (14) including a magnet (15) and an alarm circuit including a switch (3) actuated by the magnet (15), the switch (3) being present in a body (1) at the top of the housing (7) characterisedin that a port (18) is present in a wall of the housing (7) and is adapted to allow fluid into the interior of the housing (7), and in that the port (18) is sealable to isolate the fluid in the interior of the housing (7) from the body of fluid in the reservoir.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08419728A GB2162690B (en) | 1984-08-02 | 1984-08-02 | Magnetic switch for fluid level monitor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08419728A GB2162690B (en) | 1984-08-02 | 1984-08-02 | Magnetic switch for fluid level monitor |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8419728D0 GB8419728D0 (en) | 1984-09-05 |
| GB2162690A true GB2162690A (en) | 1986-02-05 |
| GB2162690B GB2162690B (en) | 1988-05-25 |
Family
ID=10564841
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08419728A Expired GB2162690B (en) | 1984-08-02 | 1984-08-02 | Magnetic switch for fluid level monitor |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2162690B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2341007A (en) * | 1998-08-13 | 2000-03-01 | David John Dean | Fluid level sensor |
| WO2000072348A1 (en) * | 1999-05-21 | 2000-11-30 | Breed Automotive Technology, Inc. | Float sensor employing a reed switch |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115014440B (en) * | 2022-06-10 | 2024-01-05 | 广东科源电气股份有限公司 | Oil immersed transformer state monitoring device |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB553090A (en) * | 1942-03-13 | 1943-05-06 | Chance Brothers & Co Ltd | Improvements relating to float-operated electric switches |
| GB866841A (en) * | 1958-12-05 | 1961-05-03 | Teddington Aircraft Controls L | Improvements in or relating to float-operated electric switch mechanism |
| GB1027253A (en) * | 1964-08-27 | 1966-04-27 | Soernewitz Elektrowaerme Veb | Electrically heated water heating and boiling apparatus |
| GB1116802A (en) * | 1964-06-19 | 1968-06-12 | Sovy U K Ltd | Apparatus for use in indicating or controlling the level of a liquid |
| GB1279504A (en) * | 1970-05-08 | 1972-06-28 | Trist Controls Ltd Ronald | Float operated signalling device |
| GB1330648A (en) * | 1969-12-25 | 1973-09-19 | Aisin Seiki | Hydraulic brake master cylinder brake fluid reservoirs |
| GB2047469A (en) * | 1979-04-27 | 1980-11-26 | Unimax Switch Ltd | Electric switch actuator |
| GB2114369A (en) * | 1982-02-03 | 1983-08-17 | Haruo Tsujimoto | A float operated magnetic switch arrangement |
-
1984
- 1984-08-02 GB GB08419728A patent/GB2162690B/en not_active Expired
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB553090A (en) * | 1942-03-13 | 1943-05-06 | Chance Brothers & Co Ltd | Improvements relating to float-operated electric switches |
| GB866841A (en) * | 1958-12-05 | 1961-05-03 | Teddington Aircraft Controls L | Improvements in or relating to float-operated electric switch mechanism |
| GB1116802A (en) * | 1964-06-19 | 1968-06-12 | Sovy U K Ltd | Apparatus for use in indicating or controlling the level of a liquid |
| GB1027253A (en) * | 1964-08-27 | 1966-04-27 | Soernewitz Elektrowaerme Veb | Electrically heated water heating and boiling apparatus |
| GB1330648A (en) * | 1969-12-25 | 1973-09-19 | Aisin Seiki | Hydraulic brake master cylinder brake fluid reservoirs |
| GB1279504A (en) * | 1970-05-08 | 1972-06-28 | Trist Controls Ltd Ronald | Float operated signalling device |
| GB2047469A (en) * | 1979-04-27 | 1980-11-26 | Unimax Switch Ltd | Electric switch actuator |
| GB2114369A (en) * | 1982-02-03 | 1983-08-17 | Haruo Tsujimoto | A float operated magnetic switch arrangement |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2341007A (en) * | 1998-08-13 | 2000-03-01 | David John Dean | Fluid level sensor |
| GB2341007B (en) * | 1998-08-13 | 2002-08-14 | David John Dean | Plant watering system |
| WO2000072348A1 (en) * | 1999-05-21 | 2000-11-30 | Breed Automotive Technology, Inc. | Float sensor employing a reed switch |
| US6380499B1 (en) | 1999-05-21 | 2002-04-30 | Breed Automotive Technology, Inc. | Float sensor employing reed switch |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8419728D0 (en) | 1984-09-05 |
| GB2162690B (en) | 1988-05-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19930802 |