CA1068373A - Fluid level indicator - Google Patents
Fluid level indicatorInfo
- Publication number
- CA1068373A CA1068373A CA260,012A CA260012A CA1068373A CA 1068373 A CA1068373 A CA 1068373A CA 260012 A CA260012 A CA 260012A CA 1068373 A CA1068373 A CA 1068373A
- Authority
- CA
- Canada
- Prior art keywords
- contact
- fluid
- indicator
- reservoir
- flexible membrane
- 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.)
- Expired
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
- G01F23/22—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 measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/24—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 measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid
- G01F23/241—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 measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid for discrete levels
-
- 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
- G01F23/14—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 measurement of pressure
- G01F23/18—Indicating, recording or alarm devices actuated electrically
- G01F23/185—Indicating, recording or alarm devices actuated electrically for discrete levels
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
- Level Indicators Using A Float (AREA)
Abstract
FLUID LEVEL INDICATOR
ABSTRACT OF THE DISCLOSURE
An indicator for monitoring the level of an operational fluid in a reservoir has a first contact and a second contact encased in flexible membrane. An electrical conductive fluid is retained in the flexible membrane. The operational fluid acts on the flexible membrane to bring the electrical conductive fluid into engagement with the first contact and the second contact to develop an operational signal for activating a light to inform an operator of the level of the operational fluid in the reservoir.
ABSTRACT OF THE DISCLOSURE
An indicator for monitoring the level of an operational fluid in a reservoir has a first contact and a second contact encased in flexible membrane. An electrical conductive fluid is retained in the flexible membrane. The operational fluid acts on the flexible membrane to bring the electrical conductive fluid into engagement with the first contact and the second contact to develop an operational signal for activating a light to inform an operator of the level of the operational fluid in the reservoir.
Description
~6~3~373 BACKGROUND OF THE INVENTION
Many devices have been conceived for informing an operator of a fluid level in a reservoir.
The most common method of fluid level detection is through the use of a float which will follow the surface of the fluid in a reservoir. The float can be directly attached to an indicator. Recently an indicator has been disclosed wherein a magnet located on the float can be utilized to operate a reed switch carried by a guide for the float. Unfortunately, floats have been known to StiCK
in many positions resulting in false fluid level indications.
In an attempt to avoid the use of a float, it is known to use reflected light or the difference in the index of refraction between a fluid and air to indicate a fluid level. Such a system requires a plurality of light emitting diodes and a corresponding number of photo sensitive tran-sistors in an electrical circuit. The electrical circuit is connected to a computer for evaluation of the information before being presented to an indicator. Such circuits can be quite complicated and costly.
In another known indicator design, the electrical capacitance between two plates located in a dielectric fluid is used as a level indicator. Whenever the dielectric fluid drops below the two plates, the capacitance increases to activate a relay or switch and operate a light to inform the operator of a predetermined fluid level. Unfortunately, over a long period of time it is possible for the dielectric fluid to break down due to the transmission of electrical current therethrough. Also, because of changea in viscosity, occasionally the fluid is retained on the plates through capillary action resulting in a false fluid level indication.
mb/J~ - 2 -~, , ~(~68373 .
SUMMARY OF THE INVENTION
I have devised an indicator for monitoring the level of an operational fluid in a reservoir. A housing has a tubular member which extends into an operational fluid, the tubular member having a base plate therein. A
first contact is attached to the base plate and extends toward the operational fluid, the first contact being connected to an electrical ground~ A second contact is attached to the base plate and extends toward the operational fluid, the second contact being connected to a signal means.
Flexible membrane means is provided surrounding the first - and second contacts, the flexible membrane means retaining an electrolytic solution. The operational fluid acts on the flexible membrane means to hold the electrolytic solution into engagement with the first and second contacts. The first contact, second contact, and electrolytic solution when brought together create a first electrical voltage which is communicated from the second contact to the signal means. The flexible membrane means allows the electrolytic solution to follow the level of the operational fluid in the reservoir and at a predetermined level interrupts communication between the first and second contacts to terminate the creation of the first electrical voltage and allow the signal means to inform an operator of the pre-determined fluid level.
It is the object of this invention to provide a fluid level indicator with a flexible member, which is responsive to the level of a fluid in a reservoir, for the development of an operational signal indicative of said fluld level.
It is another ob;ect of this invention to provide an indicator means with a flexible membrane for separating mbt,Jf, 3 ~(~6~3373 an electrical conductive fluid from an operational fluid in a reservoir, the electrical conductive fluid being adapted to provide an indicator signal to inform an operator of a predetermined fluid level.
It is another ob~ect of this invention to provide an indicator with a flexible membrane in which an electrolytic solution is retained for creating a voltage signal with a contact means upon a fluid level condition occurring in a - reservoir.
These and other ob~ects will become apparent from reading this specification and viewing the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
_ _ .
Figure 1 is a schematic illustration of a master cylinder having a sectionai view of an indicator means.
Figure 2 is an exploded view of the indicator means ln an inactivated position.
Figure 3 is another embodiment of a fluid level indicator which ls activated by depletion of fluid from a reservoir.
, , ' mb/J~, - 3a -Figure 4 is a sectional view of the indicator means in an inact i vated pO9 i tion.
Figure 5 is a sectional view through line 5-5 of Figure 4.
DETAILE _ StRlPTltN _F THE PREFERRED EMBODIMENT
In the embodlment shown in Fi~ure 1, the indicator means 10 is shown in combination with a typical master cylinder 12. However, the potential l~se of the indicator means 12 is not to be limited to such a combination since it is envisioned that the utility of the indicator means 10 can be implemented into any reservoir system requiring the actuation of a signal means 14 whenever a predetermined fluid level occurs.
The tndicator mèans 10 shown Tn Figure 1, is attached to the reservoir 16 in whTch brake or other operational fluid is retained. The hrake fluid In the reservoir 16 Ts communicated to the pistons ~not shown) in the master cylinder through compensator ports 18 in the bottom of the reservoir 16. When an operator appltes an input force to brake pedal 20, the ptstons in the master cylinder are moved past the compensator ports 18 to develop a hydraulic actuation pressure which is delivered to the front wheel brakes 22 and the rear wheel brakes 24. After repeated brake applica-tion or if a hydraulic distribution line should break, the fluid in ~he ., ~or~
reservoir ~ t be depleted. If such a condltion should occur, it Is Tmpera-tive that the operator be informed of such a condition. As a result U.S.
Federal Safety Standard Act 105A, whose effective date ;s January 1, 1976, ~ q~, r~S
will rcqulrc an indicator means 10 in the reservolr lS to monttor the fluid level of the brake fluid retained therein.
The indicator means 10 shown in Figure I has a tubular housing 26 attached to a mounting means on bracket 28. The mountlng bracket 28 has a first arm 30 and a second arm 32. The first arm 30 has a U-shaped end 34 whlch fits over the ITp 38 of the master cyllnder to flx the first arm 30 to the reservoir. The second arm 32 has a U-shaped end 36 which also fTts over the lip 38 to establlsh a mounting means or bracket 28 whlch is ~61~373 substantially paratlel to the bottom of the reservoir 16. The mounting m~ans or bracket 28 has threads 40 which are ma~ed with corresponding threads 42 on the housing 26. By adjusting the depth that the end 44 of the housing 26 extends into the hydraulic or brake fluid it is possible to set the level at which the indicator means 10 will be activated. A pin 46 ~h C~S
,f`~, or ot~er fastener means-will extsnd through a hole 48 in the mounting bracket and into a hole 50 in the housing 26 to lock or maintain the housing in a fixed position with respect to the reservoir. This type of adjustment is necessary since different braking syseems require varying amounts of brake or hydraulic fluid retention to be assured of at least enough hydraulic fluid for a single brake application after a low fluid condition has occurred.
The housing 26 has a base plate 52 whlch Ts located along the interior of the tubular sectlon 54. The base plate 52 has a series of ver~fs openings 56 around a solld center 58. The opening 56 -ill ve~t the tubular section 54 of the housing 26 to the top section 60. A cap 62 is located on the top of the houslng to prevent contaminents from entering into the reservoir through the indicator means 10. However, it is necessary to have a vent hole 64 in the cap 62. The top section 60 has a groove 66 which ~e~fq;~s ~ $a;~ first bead 68 of diaphragm 70. The diaphragm 70 has a second bead 72 whtch extends around the entire peripheral surface of the reservoir.
A cover cap 74 which surrounds the periphery of the reservoir has a shoulder 76 which engages the diaphr3gm 70 adjacent the lip 38. A bail wlre 78 acts on the cover cap 74 to create a seal between the diaphragm 70 and the interior of the reservoir 16.
The indicator means 10 has a first contact means 80 which is attached to the base plate 56 and a second contact means 82 which is also attached to the base plate 56. The flrst and second contact means each extend from the base plate 52 toward the cap 62 of the tubular section 54.
The flrst contact means 80 has a lead 84 which extends through cap 62 and cover cap 74. Lead 84 Is connected to an electrical ground 86. The second contact means 82 has a lead 87 whlch extends through cap 62 and cover cap 74.
Lead 87 Is connected through resistor 88 to the signal means 14.
~L06~3373 The signal means 14 includes a light 90 which is connected to lead 92. Lead 92 is connected to the run terminal 94 on the ignition switch of the automobile.
Lead 92 carries voltage from the battery 96 through resistor 98 to a summing junction 100. The summing junction 100 is connected to lead 86 coming from the indicator means lQ.
A lead 102 from the summing junction 100 is connected to the base of a transistor switching means 104. The light 90 is connected through lead 106 to the collector of the transistor switching means 104. The emitter of the trans-ister switching means 104 is connected to lead 84 going to ground 86.
A test circuit has a lead 108 connected to the start terminal 110 on the ignition switch of the automobile and the light 90. A ground terminal 112 is also associated with the ignition switch.
i- - The indicator means 10 has a flexible membrane 114 which surrounds the first contact means 80 and the ; second contact means 82 is attached to the solid base plate56. The flexible membrane 114 retains an electrical conductive fluid. Depending upon the type of output signal desired, the electrical conductive fluid can vary from ; salt water, NaC1 in a water solution, copper sulfate, CuS04in a water solution, sulphuric acid M2S04 or mercury. When salt water and CuS04 are used the first contact means 80 and the second contact means 82 are made of copper while the first contact means is made of lead oxide (PbO) and the second contact means is made of lead sulfate PbS04 when sulphuric acid is the elec-trolyte.
MODE OF OPERATION OF TME PREFERRED EMBODIMENT
When the operator turns his key in -the ignition switch, one blade 120 contacts run terminal 9~ and a second blade 121 contacts star-t terminal 110 and ground 112 to allow bc/l`~sl - 6 -~q316~373 current to flow through light 90 to test the operativeness of the signal means 1~. After the vehicle is started, blade 121 moves away from terminal 110 to terminate the electrical flow path to the ground terminal 112. Voltage is now carried through lead 92 past resistor 98 to the summing junction 100. At the same time the operational fluid in the reservoir acts on the flexible membrane to bring the electrical conductive fluid therein into engagement with the first contac-t 80 and the secondcontact 82. (For illustration purposes, it is assumed that the first contact means 80 is PbO and the second contact means 82 is PbS04 and the electrolyte is H2S04.) When the electrolyte is brought into contact with the terminals, a lead acid battery is created which develops an elec-trical voltage which flows in lead 87 through resistor 88 to the sum~fing junction 100.
The resistors 88 and 98 are so selected that when voltage is present in both leads 92 and 87 the effect at the summing f ' juIlctloll iS to cancel each other such that the voltage in lead 102 is approximately zero. Since the base and the emitter of the transistors see the same potential, the `transistor 104 remains in the non-conductive position.
However, if the fluid in the reservoir is depleted, as shown in Figure 2, the electrolyte follows the level of the operation~l fluid to terminate the conductive flow path between the first contact means 80 and the second contact means 82. With the termination of the voltage supplied to the summing junction 100, the voltage from the battery as modified by the resistor 98 is transmitted to the base of the transistor to turn on the NPN -transistor 106. With the electrical potential on the base raised, current can now flow through the collector from -the light 90 to complete an elec-trical circuit with ground 86 through lead 122 from the emitter. Thus, the light 90 is brought into operation and the operator is informed of a low fluid bc/~
~0613373 condition in the reservoir.
In the indica-tor means 10 shown in Figure 3, like parts are so numbered as in Figure 1.
The indicator means has a housing 26 with an insulating plastic plug 200 located in a tubular section 202. The plastic plug 200 forms the base plate for the first contact means 204 and the second contact means 206.
The first contact means 202 has a lead 208 which extends : through cap 62 to the electrical ground 86. The second contact means 206 has a lead 210 which extends through the cap 62 and is connected to light 90. The end 44 of the tubular section 26 has a groove 212 into which bead 215 of the flexible member 216 is located to surround the first contact 204 and the second contact 206 to form an operational chamber 214 in the housing 26. As shown in Figure 5, the flexible membrane 216 has a first rib 220 and a second rib 222 which extends from the edge -to the center in a triangular slope.
; When the fluid level in the reservoir 16 is above a predetermined level, the operational fluid acts on the flexiblemembrane 216 to raise the center portion ; such that the first rib 220 and the second rib 222 prevents the electrical conductive fluid from joining the first contac-t means 204 with the second contact means 206. Thus, the electrical circuit of the light 90 through lead 210 - and lead 208 to ground 86 is broken and current cannot flow from the battery source 96. ~3Owever, if the fluid in the reservoir is depleted, as shown in Figure 4, the center of the flexible membrane drops due to the weight of the electrolyte, to establish an electrical flow path between the first contact means 204 and the second contact means 206. With the electrical circuit completed, thc voltage from the ba-ttery operates the light 90 to inform the operator of this low fluid level condition in the reservoir.
bc~
Many devices have been conceived for informing an operator of a fluid level in a reservoir.
The most common method of fluid level detection is through the use of a float which will follow the surface of the fluid in a reservoir. The float can be directly attached to an indicator. Recently an indicator has been disclosed wherein a magnet located on the float can be utilized to operate a reed switch carried by a guide for the float. Unfortunately, floats have been known to StiCK
in many positions resulting in false fluid level indications.
In an attempt to avoid the use of a float, it is known to use reflected light or the difference in the index of refraction between a fluid and air to indicate a fluid level. Such a system requires a plurality of light emitting diodes and a corresponding number of photo sensitive tran-sistors in an electrical circuit. The electrical circuit is connected to a computer for evaluation of the information before being presented to an indicator. Such circuits can be quite complicated and costly.
In another known indicator design, the electrical capacitance between two plates located in a dielectric fluid is used as a level indicator. Whenever the dielectric fluid drops below the two plates, the capacitance increases to activate a relay or switch and operate a light to inform the operator of a predetermined fluid level. Unfortunately, over a long period of time it is possible for the dielectric fluid to break down due to the transmission of electrical current therethrough. Also, because of changea in viscosity, occasionally the fluid is retained on the plates through capillary action resulting in a false fluid level indication.
mb/J~ - 2 -~, , ~(~68373 .
SUMMARY OF THE INVENTION
I have devised an indicator for monitoring the level of an operational fluid in a reservoir. A housing has a tubular member which extends into an operational fluid, the tubular member having a base plate therein. A
first contact is attached to the base plate and extends toward the operational fluid, the first contact being connected to an electrical ground~ A second contact is attached to the base plate and extends toward the operational fluid, the second contact being connected to a signal means.
Flexible membrane means is provided surrounding the first - and second contacts, the flexible membrane means retaining an electrolytic solution. The operational fluid acts on the flexible membrane means to hold the electrolytic solution into engagement with the first and second contacts. The first contact, second contact, and electrolytic solution when brought together create a first electrical voltage which is communicated from the second contact to the signal means. The flexible membrane means allows the electrolytic solution to follow the level of the operational fluid in the reservoir and at a predetermined level interrupts communication between the first and second contacts to terminate the creation of the first electrical voltage and allow the signal means to inform an operator of the pre-determined fluid level.
It is the object of this invention to provide a fluid level indicator with a flexible member, which is responsive to the level of a fluid in a reservoir, for the development of an operational signal indicative of said fluld level.
It is another ob;ect of this invention to provide an indicator means with a flexible membrane for separating mbt,Jf, 3 ~(~6~3373 an electrical conductive fluid from an operational fluid in a reservoir, the electrical conductive fluid being adapted to provide an indicator signal to inform an operator of a predetermined fluid level.
It is another ob~ect of this invention to provide an indicator with a flexible membrane in which an electrolytic solution is retained for creating a voltage signal with a contact means upon a fluid level condition occurring in a - reservoir.
These and other ob~ects will become apparent from reading this specification and viewing the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
_ _ .
Figure 1 is a schematic illustration of a master cylinder having a sectionai view of an indicator means.
Figure 2 is an exploded view of the indicator means ln an inactivated position.
Figure 3 is another embodiment of a fluid level indicator which ls activated by depletion of fluid from a reservoir.
, , ' mb/J~, - 3a -Figure 4 is a sectional view of the indicator means in an inact i vated pO9 i tion.
Figure 5 is a sectional view through line 5-5 of Figure 4.
DETAILE _ StRlPTltN _F THE PREFERRED EMBODIMENT
In the embodlment shown in Fi~ure 1, the indicator means 10 is shown in combination with a typical master cylinder 12. However, the potential l~se of the indicator means 12 is not to be limited to such a combination since it is envisioned that the utility of the indicator means 10 can be implemented into any reservoir system requiring the actuation of a signal means 14 whenever a predetermined fluid level occurs.
The tndicator mèans 10 shown Tn Figure 1, is attached to the reservoir 16 in whTch brake or other operational fluid is retained. The hrake fluid In the reservoir 16 Ts communicated to the pistons ~not shown) in the master cylinder through compensator ports 18 in the bottom of the reservoir 16. When an operator appltes an input force to brake pedal 20, the ptstons in the master cylinder are moved past the compensator ports 18 to develop a hydraulic actuation pressure which is delivered to the front wheel brakes 22 and the rear wheel brakes 24. After repeated brake applica-tion or if a hydraulic distribution line should break, the fluid in ~he ., ~or~
reservoir ~ t be depleted. If such a condltion should occur, it Is Tmpera-tive that the operator be informed of such a condition. As a result U.S.
Federal Safety Standard Act 105A, whose effective date ;s January 1, 1976, ~ q~, r~S
will rcqulrc an indicator means 10 in the reservolr lS to monttor the fluid level of the brake fluid retained therein.
The indicator means 10 shown in Figure I has a tubular housing 26 attached to a mounting means on bracket 28. The mountlng bracket 28 has a first arm 30 and a second arm 32. The first arm 30 has a U-shaped end 34 whlch fits over the ITp 38 of the master cyllnder to flx the first arm 30 to the reservoir. The second arm 32 has a U-shaped end 36 which also fTts over the lip 38 to establlsh a mounting means or bracket 28 whlch is ~61~373 substantially paratlel to the bottom of the reservoir 16. The mounting m~ans or bracket 28 has threads 40 which are ma~ed with corresponding threads 42 on the housing 26. By adjusting the depth that the end 44 of the housing 26 extends into the hydraulic or brake fluid it is possible to set the level at which the indicator means 10 will be activated. A pin 46 ~h C~S
,f`~, or ot~er fastener means-will extsnd through a hole 48 in the mounting bracket and into a hole 50 in the housing 26 to lock or maintain the housing in a fixed position with respect to the reservoir. This type of adjustment is necessary since different braking syseems require varying amounts of brake or hydraulic fluid retention to be assured of at least enough hydraulic fluid for a single brake application after a low fluid condition has occurred.
The housing 26 has a base plate 52 whlch Ts located along the interior of the tubular sectlon 54. The base plate 52 has a series of ver~fs openings 56 around a solld center 58. The opening 56 -ill ve~t the tubular section 54 of the housing 26 to the top section 60. A cap 62 is located on the top of the houslng to prevent contaminents from entering into the reservoir through the indicator means 10. However, it is necessary to have a vent hole 64 in the cap 62. The top section 60 has a groove 66 which ~e~fq;~s ~ $a;~ first bead 68 of diaphragm 70. The diaphragm 70 has a second bead 72 whtch extends around the entire peripheral surface of the reservoir.
A cover cap 74 which surrounds the periphery of the reservoir has a shoulder 76 which engages the diaphr3gm 70 adjacent the lip 38. A bail wlre 78 acts on the cover cap 74 to create a seal between the diaphragm 70 and the interior of the reservoir 16.
The indicator means 10 has a first contact means 80 which is attached to the base plate 56 and a second contact means 82 which is also attached to the base plate 56. The flrst and second contact means each extend from the base plate 52 toward the cap 62 of the tubular section 54.
The flrst contact means 80 has a lead 84 which extends through cap 62 and cover cap 74. Lead 84 Is connected to an electrical ground 86. The second contact means 82 has a lead 87 whlch extends through cap 62 and cover cap 74.
Lead 87 Is connected through resistor 88 to the signal means 14.
~L06~3373 The signal means 14 includes a light 90 which is connected to lead 92. Lead 92 is connected to the run terminal 94 on the ignition switch of the automobile.
Lead 92 carries voltage from the battery 96 through resistor 98 to a summing junction 100. The summing junction 100 is connected to lead 86 coming from the indicator means lQ.
A lead 102 from the summing junction 100 is connected to the base of a transistor switching means 104. The light 90 is connected through lead 106 to the collector of the transistor switching means 104. The emitter of the trans-ister switching means 104 is connected to lead 84 going to ground 86.
A test circuit has a lead 108 connected to the start terminal 110 on the ignition switch of the automobile and the light 90. A ground terminal 112 is also associated with the ignition switch.
i- - The indicator means 10 has a flexible membrane 114 which surrounds the first contact means 80 and the ; second contact means 82 is attached to the solid base plate56. The flexible membrane 114 retains an electrical conductive fluid. Depending upon the type of output signal desired, the electrical conductive fluid can vary from ; salt water, NaC1 in a water solution, copper sulfate, CuS04in a water solution, sulphuric acid M2S04 or mercury. When salt water and CuS04 are used the first contact means 80 and the second contact means 82 are made of copper while the first contact means is made of lead oxide (PbO) and the second contact means is made of lead sulfate PbS04 when sulphuric acid is the elec-trolyte.
MODE OF OPERATION OF TME PREFERRED EMBODIMENT
When the operator turns his key in -the ignition switch, one blade 120 contacts run terminal 9~ and a second blade 121 contacts star-t terminal 110 and ground 112 to allow bc/l`~sl - 6 -~q316~373 current to flow through light 90 to test the operativeness of the signal means 1~. After the vehicle is started, blade 121 moves away from terminal 110 to terminate the electrical flow path to the ground terminal 112. Voltage is now carried through lead 92 past resistor 98 to the summing junction 100. At the same time the operational fluid in the reservoir acts on the flexible membrane to bring the electrical conductive fluid therein into engagement with the first contac-t 80 and the secondcontact 82. (For illustration purposes, it is assumed that the first contact means 80 is PbO and the second contact means 82 is PbS04 and the electrolyte is H2S04.) When the electrolyte is brought into contact with the terminals, a lead acid battery is created which develops an elec-trical voltage which flows in lead 87 through resistor 88 to the sum~fing junction 100.
The resistors 88 and 98 are so selected that when voltage is present in both leads 92 and 87 the effect at the summing f ' juIlctloll iS to cancel each other such that the voltage in lead 102 is approximately zero. Since the base and the emitter of the transistors see the same potential, the `transistor 104 remains in the non-conductive position.
However, if the fluid in the reservoir is depleted, as shown in Figure 2, the electrolyte follows the level of the operation~l fluid to terminate the conductive flow path between the first contact means 80 and the second contact means 82. With the termination of the voltage supplied to the summing junction 100, the voltage from the battery as modified by the resistor 98 is transmitted to the base of the transistor to turn on the NPN -transistor 106. With the electrical potential on the base raised, current can now flow through the collector from -the light 90 to complete an elec-trical circuit with ground 86 through lead 122 from the emitter. Thus, the light 90 is brought into operation and the operator is informed of a low fluid bc/~
~0613373 condition in the reservoir.
In the indica-tor means 10 shown in Figure 3, like parts are so numbered as in Figure 1.
The indicator means has a housing 26 with an insulating plastic plug 200 located in a tubular section 202. The plastic plug 200 forms the base plate for the first contact means 204 and the second contact means 206.
The first contact means 202 has a lead 208 which extends : through cap 62 to the electrical ground 86. The second contact means 206 has a lead 210 which extends through the cap 62 and is connected to light 90. The end 44 of the tubular section 26 has a groove 212 into which bead 215 of the flexible member 216 is located to surround the first contact 204 and the second contact 206 to form an operational chamber 214 in the housing 26. As shown in Figure 5, the flexible membrane 216 has a first rib 220 and a second rib 222 which extends from the edge -to the center in a triangular slope.
; When the fluid level in the reservoir 16 is above a predetermined level, the operational fluid acts on the flexiblemembrane 216 to raise the center portion ; such that the first rib 220 and the second rib 222 prevents the electrical conductive fluid from joining the first contac-t means 204 with the second contact means 206. Thus, the electrical circuit of the light 90 through lead 210 - and lead 208 to ground 86 is broken and current cannot flow from the battery source 96. ~3Owever, if the fluid in the reservoir is depleted, as shown in Figure 4, the center of the flexible membrane drops due to the weight of the electrolyte, to establish an electrical flow path between the first contact means 204 and the second contact means 206. With the electrical circuit completed, thc voltage from the ba-ttery operates the light 90 to inform the operator of this low fluid level condition in the reservoir.
bc~
Claims (8)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An indicator for monitoring the level of an operational fluid in a reservoir, comprising:
a housing having a tubular member which extends into an operational fluid, said tubular member having a base plate therein;
a first contact attached to said base plate and extending toward said operational fluid, said first contact being connected to an electrical ground;
a second contact attached to said base plate and extending toward said operational fluid, said second contact being connected to a signal means; and flexible membrane means surrounding said first and second contacts, said flexible membrane means retaining an electrolytic solution, said operational fluid acting on said flexible membrane means to hold said electrolytic solution into engagement with said first and second contacts, said first contact, second contact, and electrolytic solution when brought together creating a first electrical voltage, said electrical voltage being communicated from said second contact to said signal means, said flexible membrane means allowing said electrolytic solution to follow the level of the operational fluid in said reservoir and at a predetermined level interrupting communication between the first and second contacts to terminate the creation of said first electrical voltage and allow said signal means to inform an operator of said predetermined fluid level.
a housing having a tubular member which extends into an operational fluid, said tubular member having a base plate therein;
a first contact attached to said base plate and extending toward said operational fluid, said first contact being connected to an electrical ground;
a second contact attached to said base plate and extending toward said operational fluid, said second contact being connected to a signal means; and flexible membrane means surrounding said first and second contacts, said flexible membrane means retaining an electrolytic solution, said operational fluid acting on said flexible membrane means to hold said electrolytic solution into engagement with said first and second contacts, said first contact, second contact, and electrolytic solution when brought together creating a first electrical voltage, said electrical voltage being communicated from said second contact to said signal means, said flexible membrane means allowing said electrolytic solution to follow the level of the operational fluid in said reservoir and at a predetermined level interrupting communication between the first and second contacts to terminate the creation of said first electrical voltage and allow said signal means to inform an operator of said predetermined fluid level.
2. The indicator, as recited in claim 1, wherein said housing includes:
mounting means for attaching said indicator to said reservoir, said mounting means being adjustable to establish said predetermined level through which the electrical conductive fluid connects the first contact with the second contact.
mounting means for attaching said indicator to said reservoir, said mounting means being adjustable to establish said predetermined level through which the electrical conductive fluid connects the first contact with the second contact.
3. The indicator, as recited in claim 2, wherein said mounting means includes:
pin means for locking said tubular member in a fixed position once said predetermined level is established.
pin means for locking said tubular member in a fixed position once said predetermined level is established.
4. The indicator, as recited in claim 3, wherein said housing further includes:
cap means attached to said tubular member having a vent therein to prevent the formation of a resistive force which would oppose the movement of the flexible membrane means by said predetermined level.
cap means attached to said tubular member having a vent therein to prevent the formation of a resistive force which would oppose the movement of the flexible membrane means by said predetermined level.
5. The indicator, as recited in claim 1, wherein said electrolytic solution is H2SO4 and said first contact means is made of PbO and said second contact means is made of PbSO4, said H2SO4 upon contacting said PbO contact and said PbSO4 contact causing a voltage to-be transmitted to said signal means.
6. The indicator, as recited in claim 1, wherein said electrolytic solution is CuSO4 and said first and second contact means are plates made of Cu, said CuSO4 upon engaging said first and second Cu plates causing a voltage to be transmitted to said signal means.
7. The indicator, as recited in claim 1, wherein said signal means includes:
a second source of electrical voltage;
a light connected to said second electrical voltage;
and transistor means having a collector connected to said light, a base connected to said second contact means, and an emitter connected to an electrical ground, said first electrical voltage acting on said base of the transistor to prevent said second source of electrical voltage from operating said light when the reservoir fluid is above said predetermined level.
a second source of electrical voltage;
a light connected to said second electrical voltage;
and transistor means having a collector connected to said light, a base connected to said second contact means, and an emitter connected to an electrical ground, said first electrical voltage acting on said base of the transistor to prevent said second source of electrical voltage from operating said light when the reservoir fluid is above said predetermined level.
8. An indicator for monitoring the level of an operational fluid in a reservoir, comprising:
a housing having a tubular member which extends into said fluid, said tubular member having a base plate therein;
contact means attached to said base plate and extending toward said fluid, said contact means being connected to a signal means;
flexible membrane means surrounding said contact means, said flexible means retaining an electrolytic solution;
and dividing means for separating said flexible membrane into a first volume and second volume when said fluid in the reservoir deforms said flexible membrane means in an upward position, said membrane and said electrolytic solution responding to changes in said fluid in the reservoir to establish communication through said divider means when the fluid in the reservoir reaches a predetermined level to engage said contact means to develop an electrical voltage therein and transmit an input to said signal means.
a housing having a tubular member which extends into said fluid, said tubular member having a base plate therein;
contact means attached to said base plate and extending toward said fluid, said contact means being connected to a signal means;
flexible membrane means surrounding said contact means, said flexible means retaining an electrolytic solution;
and dividing means for separating said flexible membrane into a first volume and second volume when said fluid in the reservoir deforms said flexible membrane means in an upward position, said membrane and said electrolytic solution responding to changes in said fluid in the reservoir to establish communication through said divider means when the fluid in the reservoir reaches a predetermined level to engage said contact means to develop an electrical voltage therein and transmit an input to said signal means.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US61754175A | 1975-09-29 | 1975-09-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1068373A true CA1068373A (en) | 1979-12-18 |
Family
ID=24474056
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA260,012A Expired CA1068373A (en) | 1975-09-29 | 1976-08-27 | Fluid level indicator |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5242759A (en) |
| AU (1) | AU1770076A (en) |
| CA (1) | CA1068373A (en) |
| DE (1) | DE2643675A1 (en) |
| FR (1) | FR2325910A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61160212U (en) * | 1985-03-27 | 1986-10-04 | ||
| JPS6440673A (en) * | 1987-07-31 | 1989-02-10 | Wakayama Prefecture | Fire retardant processing of fiber |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1933648A1 (en) * | 1969-07-02 | 1971-01-07 | Michael Weidacher | Device to control the water level |
| DE2344991C3 (en) * | 1973-09-06 | 1979-06-13 | Japan Storage Battery Co., Ltd., Kyoto (Japan) | Device for monitoring the electrolyte level in a battery |
-
1976
- 1976-08-27 CA CA260,012A patent/CA1068373A/en not_active Expired
- 1976-09-13 AU AU17700/76A patent/AU1770076A/en not_active Expired
- 1976-09-20 FR FR7628131A patent/FR2325910A1/en active Granted
- 1976-09-28 DE DE19762643675 patent/DE2643675A1/en active Pending
- 1976-09-29 JP JP11610376A patent/JPS5242759A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| FR2325910B1 (en) | 1979-09-28 |
| FR2325910A1 (en) | 1977-04-22 |
| JPS5242759A (en) | 1977-04-02 |
| AU1770076A (en) | 1978-03-23 |
| DE2643675A1 (en) | 1977-04-07 |
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