Liquid level sensor, pump system means and circuit means

• US 4,171,932 A
• Filed: 09/23/1977
• Issued: 10/23/1979
• Est. Priority Date: 09/23/1977
• Status: Expired due to Term

• Current Assignee: Nartron Corporation
• Original Assignee: Nartron Corporation
• Inventors: Miller, Gerald K.
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Look, Edward
• Application Number:
  US05/836,013
• Time in Patent Office: 760 Days
• Field of Search: 417/7, 417/36, 417/44, 417/38, 417/12, 417/63, 137/392, 307/118, 318/482
• US Class Current: 417/36
• CPC Class Codes: F04D 15/0218 the condition being a liquid level or a lack of liquid supply
• CPC Class Codes: G01F 23/243 Schematic arrangements of probes combined with measuring circuits
• CPC Class Codes: G05D 9/12 characterised by the use of electric means

Abstract

A plurality of probes are situated as to experience being touched by the liquid being monitored; when at least one of such probes is touched by the liquid related electrical circuit means becomes energized as to cause related pumping means to be activated thereby pumping some of the monitored liquid to, in turn, reduce the level of such monitored liquid; when the level of the monitored liquid decreases to a predetermined level, the pumping means is automatically de-activated; during periods wherein there might occur a momentary splashing or sloshing of the monitored liquid, time delay means serves to correspondingly delay activation of said pumping means thereby preventing unnecessary activation of the pumping means.

Claims

1. Liquid level sensing apparatus, comprising at least first and second electrical probe means, electrical logic circuit means operatively interconnecting said at least first and second electrical probe means, said electrical logic circuit means being effective for creating a first output of a first electrical magnitude when said liquid is at a predetermined elevation relative to said at least first and second electrical probe means as to be in contact with said first and second electrical probe means, said electrical logic circuit means being effective to continue creating said first output for a first predetermined span of time next following that instant at which said level of said liquid decreases from said predetermined elevation to a second elevation whereat said liquid ceases to contact both said first and second electrical probe means, said electrical logic circuit means being effective to prevent the creation of said first output of said first electrical magnitude by instead creating a second output of a second electrical magnitude for a second predetermined span of time next following that instant at which said liquid level moves from an elevation relatively lower than said predetermined elevation and attains said predetermined elevation, and output means effective for receiving said first and second outputs and producing a related response relative thereto.

2. Apparatus according to claim 1 and further comprising timing means, said timing means being effective to cause a sensory output signal to be produced whenever said first output of a first electrical magnitude has existed continuously for a second preselected span of time.

3. Apparatus according to claim 2 and further comprising related output circuit means, wherein said output means comprises solid state semiconductor means effective for electrically opening and closing said related output circuit means, and further comprising liquid pumping means, said pumping means being actuated into its pumping cycle whenever said semiconductor means closes said related output circuit means, said pumping means comprising a pump assembly and an electric motor for driving said pump assembly, wherein said related output circuit means is operatively electrically connected to said electric motor, wherein said electric motor is energized upon said semiconductor means closing said related output circuit means, and further comprising generating means for generating a second sensory signal, said generating means being operatively electrically connected to said related output circuit means as to be energized whenever said related output circuit means is closed.

4. Apparatus according to claim 1 wherein said first and second electrical probe means are respectively effective to be contacted by said liquid at differing elevations.

5. Apparatus according to claim 4 wherein said first and second electrical probe means are each positioned as to be generally laterally disposed to the general plane of the level of said liquid.

6. Apparatus according to claim 1 wherein said output means comprises electrically energizable relay means effective for opening and closing related output circuit means.

7. Apparatus according to claim 6 and further comprising liquid pumping means, said pumping means being actuated into its pumping cycle whenever said relay means closes said related output circuit means.

8. Apparatus according to claim 7 and further comprising sensory signal means, said sensor signal means being activated whenever said pumping means is actuated into its pumping cycle.

9. Apparatus according to claim 7 wherein said pumping means comprises a pump assembly and an electric motor for driving said pump assembly, and wherein said electric motor is energized upon said relay means closing said related output circuit means.

10. Apparatus according to claim 7 wherein said pumping means comprises a pump assembly and an electric motor for driving said pump assembly, wherein said related output circuit means is operatively electrically connected to said electric motor, wherein said electric motor is energized upon said relay means closing said related output circuit means, and further comprising sensory signal generating means, said sensory signal generating means being operatively electrically connected to said related output circuit means as to be energized whenever said related output circuit means is closed.

11. Apparatus according to claim 6 wherein said output means further comprises solid state semiconductor means in circuit with said relay means, said semiconductor means being placed into a conductive state when acted upon by said first output of a first electrical magnitude to thereby energize said relay means and cause closing of said related output circuit means.

12. Apparatus according to claim 6 wherein said electrical logic circuit means comprises R-C network means situated generally between the first and second electrical probe means and said output means.

13. Apparatus according to claim 1 wherein said output means comprises solid state semiconductor means effective for electrically opening and closing associated output circuit means.

14. Apparatus according to claim 13 and further comprising liquid pumping means, said pumping means being actuated into its pumping cycle whenever said semiconductor means closes said related output circuit means.

15. Apparatus according to claim 14 and further comprising signal means, said signal means being activated whenever said pumping means is actuated into its pumping cycle.

16. Apparatus according to claim 14 wherein said pumping means comprises a pump assembly and an electric motor for driving said pump assembly, and wherein said electric motor is energized upon said semiconductor means closing said related output circuit means.

17. Apparatus according to claim 14 wherein said pumping means comprises a pump assembly and an electric motor for driving said pump assembly, wherein said related output circuit means is operatively electrically connected to said electric motor, wherein said electric motor is energized upon said semiconductor means closing said related output circuit means, and further comprising sensory signal generating means, said sensory signal generating means being operatively electrically connected to said related output circuit means as to be energized whenever said related output circuit means is closed.

18. Apparatus according to claim 1 wherein said first electrical probe means is effective for sensing the presence of said liquid only when said liquid has attained at least said predetermined elevation, wherein said second electrical probe means is effective for sensing the presence of said liquid only when said liquid has attained at least a second predeteremined elevation which is less than said predetermined elevation, wherein said electrical logic means comprises inhibiting means, wherein said inhibiting means comprises first and second time delay means, wherein said first time delay means is effective for causing said second output of a second electrical magnitude to be created for said second predetermined span of time whenever said liquid level moves from an elevation relatively lower than said predetermined elevation and attains said predetermined elevation, and wherein said second time delay means is effective for causing said first output of a first electrical magnitude to be continued to be created for said first predetermined span of time whenever said liquid level moves from said predetermined elevation to said second elevation.

19. Electrical circuit means for detecting the level of an associated liquid and creating a related fourth signal comprising first branch circuit means, second branch circuit means, said first branch circuit means comprising first electrically conductive probe means responsive to contact with said liquid when said liquid is at a first relatively low level for completing a first electrical circuit therethrough and producing a first signal, first electrical logic means responsive to said first signal for in turn producing a second signal indicative thereof, said second branch circuit means comprising second electrically conductive probe means responsive to contact with said liquid when said liquid is at a second relatively high level for completing a second electrical circuit therethrough and producing a third signal, second electrical logic means responsive to said third signal for in turn producing a fourthsignal indicative thereof, third electrical logic means effective to receive said second and fourth signals and in response thereto causing a first output signal to be produced, first electrical timing means effective to prevent said second signal from being applied to said second electrical logic means for a first preselected span of time immediately following initial contact between said second electrically conductive probe means and said liquid when said liquid is at said second relatively high level. and second electrical timing means, said second electrical timing means being effective to cause said first signal to continue to be applied to said first electrical logic means for a second preselected span of time immediately subsequent to both the production of said second signal and the termination of said contact between said liquid and said first and second electrically conductive probe means.

20. Electrical circuit means according to claim 19 and further comprising Darlington circuit means, and wherein said first output signal is applied to said Darlington circuit means in order to cause said Darlington circuit means to be conductive.

21. Electrical circuit means according to claim 19 wherein said first branch circuit means comprises third branch circuit means, and wherein said third branch circuit means is effective for applying said first signal to also said second electrical logic means.

22. Electrical circuit means according to claim 19 and further comprising third timing means, and sensory warning means, said third timing means being effective to cause activation of said sensory warning means upon the expiration of a third preselected span of time measured from the instant of production of said fourth signal.

23. Electrical circuit means for detecting the level of an associated liquid and creating a related output, comprising first branch circuit means, second branch circuit means, said first branch circuit means comprising first electrically conductive probe means responsive to contact with said liquid when said liquid is at a first relatively low level for completing a first electrical circuit therethrough and producing a first signal, first electrical logic means responsive to said first signal for in turn producing a second signal indicative thereof, said second branch circuit means comprising second electrically conductive probe means responsive to contact with said liquid when said liquid is at a second relatively high level for completing a second electrical circuit therethrough and producing a third signal, second electrical logic means responsive to said third signal for in turn producing a fourth signal indicative thereof, third electrical logic means effective to receive said second and fourth signals and in response thereto causing a first output signal to be produced, electrically insulating housing means sealed against admission of said liquid into the interior thereof, printed circuit board means situated in said interior, said first and second branch circuit means carried by said printed circuit board means, said first second and third electrical logic means carried by said printed circuit board means, aperture means formed in said housing means sealingly receiving said first and second probe means therethrough, a first mounting aperture formed in said printed circuit board means effective for receiving said first probe means, and a plurality of second mounting apertures spaced from each other and formed in said printed circuit board means, said second probe means being selectively mounted to any of said second mounting apertures.

24. Electrical circuit means for detecting the level of an associated liquid and creating a related output, comprising first branch circuit means, second branch circuit means, said first branch circuit means comprising first electrically conductive probe means responsive to contact with said liquid when said liquid is at a first relatively low level for completing a first electrical circuit therethrough and producing a first signal, first electrical logic means responsive to said first signal for in turn producing a second signal indicative thereof, said second branch circuit means comprising second electrically conductive probe means responsive to contact with said liquid when said liquid is at a second relatively high level for completing a second electrical circuit therethrough and producing a third signal, second electrical logic means responsive to said third signal for in turn producing a fourth signal indicative thereof, third electrical logic means effective to receive said second and fourth signals and in responsive thereto causing a first output signal to be produced, electrically insulating housing means sealed against admission of said liquid into the interior thereof, printed circuit board means situated in said interior, said first and second branch circuit means carried by said printed circuit board means, said first second and third electrical logic means carried by said printed circuit board means, aperture means formed in said housing means sealingly receiving said first and second probe means therethrough, a first mounting aperture formed in said printed circuit board means effective for receiving said first probe means, and a second mounting aperture formed in said printed circuit board means for receiving said second probe means.

25. Electrical circuit means for detecting the level of an associated liquid and creating a related output, comprising first branch circuit means, second branch circuit means, said first branch circuit means comprising first electrically conductive probe means responsive to contact with said liquid when said liquid is at a first relatively low level for completing a first electrical circuit therethrough and producing a first signal, first electrical logic means responsive to said first signal for in turn producing a second signal indicative thereof, said second branch circuit means comprising second electrically conductive probe means responsive to contact with said liquid when said liquid is at a second relatively high level for completing a second electrical circuit therethrough and producing a third signal, second electrical logic means responsive to said third signal for in turn producing a fourth signal indicative thereof, and third electrical logic means effective to receive said second and fourth signals and in response thereto causing a first output signal to be produced, electrically insulating housing means sealed against admission of said liquid into the interior thereof, printed circuit board means situated in said interior, said first and second branch circuit means carried by said printed circuit board means, said first second and third electrical logic means carried by said printed circuit board means, aperture means formed in said housing means sealingly receiving said first and second probe means therethrough, and said first and second probe means being carried by said printed circuit board means.

26. Liquid level sensing and pumping apparatus, comprising a first electrically conductive probe situated as to be placed in contact with said liquid when the elevational level of said liquid attains a first predetermined relatively low elevational level, a second electrically conductive probe situated as to be placed in contact with said liquid when the elevational level of said liquid attains a second predetermined relatively high elevational level, said first electrically conductive probe being in contact with said liquid in the entire range of elevational liquid levels from and including said first predetermined relatively low elevational level and said second predetermined relatively high elevational level, pumping means effective when energized to pump said liquid to a selected area, and electrical circuit means electrically operatively interconnecting said first and second probes to said pumping means, said electrical circuit means being effective to cause energization of said pumping means only after said second electrically conductive probe has been continously in said contact with said liquid for a first preselected span of time, said electrical circuit means being effective after initially causing said energization to continue said energization of said pumping means even as the elevational level of said liquid decreases from said second predetermined relatively high elevational level and progresses toward said first predetermined relatively low elevational level, said electrical circuit means also being effective after initially causing said energization to continue said energization of said pumping means not only as the elevational level of said liquid decreases from said second level toward said first level but also being effective to continue said energization until the elevational level of said liquid decreases to a third elevational level which is elevationally lower than said first predetermined relatively low elevational level, the elevational difference between said first predetermined relatively low elevational level and said third elevational level being determined by a second preselected span of time of said continued energization, said second preselected span of time being measured from the instant at which said decreasing elevational level of said liquid ceases to contact said first probe.