CA1197593A

CA1197593A - Method and apparatus for continual monitoring and regulating of the temperature of a dispensed fluid

Info

Publication number: CA1197593A
Application number: CA000454536A
Authority: CA
Inventors: Mark Reed
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-05-17
Filing date: 1984-05-17
Publication date: 1985-12-03

Abstract

ABSTRACT

In obtaining the dispensing of a fluid of a given temperature, it is common to mix two similar fluids of different temperatures to arrive at the desired temperature of the mix. In this invention, the temperature of the discharge from a faucet, showerhead or hose at a bathtub, sink, or shower enclosure, is continually monitored and adjusted to a selected temperature by an electrical control circuit in conjunction with sensing means and driven valves controlling inflow from two pipes of similar fluids of differing temperatures. The invention will be of great value in use with water supply plumbing. Several accessory features, such as flow rate, volume, and timer control may be incorporated into the system.

Description

SPEC I FICATION

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

This invention relates to the automated attainment and maintenance of a desired temperature of the discharge Erom a faucet, showerhead or hose at a bathtub, sink, shower enclosure or like re.ceptacle~ The device works by automatically controlling the proportions of a mix of two similar fluids of differing temperatuxes. Optional faatures include the automatic attainment and maintenance of the flow rate of the mix, of automatic start-up with a timer, and of automatic halting when a given volume is dispensed.

This invention is a unique assemblage of known components and methods. The invention is comprised of plumbing fixtures~ piping, valves, drives, sensors, electronic relays, control circuitry, and control panel, all of which are, in various orms, in current use.
They are brought together, each in a specific form, to comprise a new system which is this invention.

DESCRIPTION OF THE PRIOR TECHNOLOGY

In obtaining the dispensing of a fluid of a given temperature, it is common to Tnix two fluids of different temperatures to arrive at the desired temperature of the mix. A knob or lever controlled valve is usually adju~sted by hand to allow the fluid of one tempera-ture to flow at a rate to be felt or observed by the adjusting person. Mo6 t oEten, each of two valves is controlled by i-ts own kJlob or lever bu-t it is not urlcc)mmon to have a single knob oc lever controlling bo-th valves. The fluids are mii~ed together, usuaLly at a poin-t immediately aEter the Eluids exit their respective valves, which are usually in close proximity to each other.

To ensure that the resultan-t mix is the desired temperature, the user almost always relies on testing the fluid, commonly water, by placing a hand or fingers in the fluid mix dispensed from -the system. The valves are adjusted manually on a -trial and error basis until the user is satisfied with -the mix. When a user wishes to maintain a fixed tempera~ure a-t a fixed rate oE flow, such as when having a shower, he rnust first sense by touch any change which invariably occuxs, and then, again by trial and error, adjust the valves manually.

If a user wishes a specific volume, an example being to fill a ba-thtub, visual observation is required so that the valves may be shut manually when the desired volume has been dispensed.

To save time, the user often attends to o-ther activities while, as in this example, -the bathtub is filling, periodically checking or hoping to return in -time to shut off the valves before an overflow situation occursO

Some attempts have been made to reduce -the fluctuations oE

temperature and flow rate~ Mechanical devices in plumbing systems compensate Eor sudden changes in pressure such as when a toilet flushes. The change is always evident, however, to the user.
Single lever or knob fauce-ts have been introduced -to simpliEy -the trial and error method of mix selectionO The trial and error me-thod, involving touch tes-ting or observa-tion, is still essential Eor successful oparation. Also, the degree o f:Low ra-te control sensi-tivity available in current devices does not eliminate the need for in-termi-tten-t manual adjustment by the user.

The pursui-t of efficiency has necessitated the invention and application of electronic fluid control systems. There are devices which monitor and control the flow rate of fluids as xequired on a continuous basis by sensing the characteristics, including temperature, of the Eluids, and governing their flow accordingly.
10 Other devices yovern the ra-te a-t which fluid is used depending on multiple variables which change the required flow ra-te. Still other devices provide a means for electronically controlling the blending of two fluids in-to one stream. In most such devices, the selection of temperature, or other charac-teristic, either effects a pxeset opening or closing of certain valves controlling flow of fluids of supposed temperatures, or other cha:racteristics, regardless of what the actual temperatures or values are, or, in more sophisticated devices, effects periodic or preset opening and closing of certain valves controlling ingredient Eluids of known 20 temperatures, or o-ther characteristics, depending on a rough calculation to predict the approximate result, rather than on an ongoing measurement of -the result or of -the inflowing fluids by the control circuit and an accordingly increasingly refined adjustment as here. The most similar existing devices to the invention herein described are laundry machines or dishwashers wi-th electronic controls of the temperature and volume of wa-ter required. Of less similarity -to the present invention are devices that electronically control the manipulation oE -the temperature oE
a discharge of fluid, for example, by application oE ambient heat or coldness to the mix of the fluid or to an ingredient of -the mix, or by applying increased or decreased pumping or ambient pressure to increase or decrease the flow of an ingredien-t of the ~75~3 IniX .

SUMMARY OF THE INVENTION

DESCRIPTION OF THE DRAWING~

Figure 1 is a drawing oE the control panel.

Figure 2 is a schematic drawing o~ -the invention system.

Figure 3 is a logic diagram for the -tempera-ture and flow ra-te control aspect of the microprocessor.

Figure 4 is a logic diagxam for the volume control aspect of the microprocessor.

Figure 5 is a logic diagram for the Elow stop aspect of the microprocessor.

Figure 6 is a logic diagram Eor the pre-set command control aspect of the microprocessor~

GENERAL VESCRIPTION

An object oE the present invention is to provide an electronic control for the attainment, moni-toring and regulating of the temperature oE a fLuid discharge from a faucet, showerhead or hose at a bathtub, sink, shower enclosure or like receptacle, by monitorîng and regulating -the proportions of the mix comprised of two similar fluids of differing temperatuxes. At the same -time, S~3 this invention ~an also attain, monitor and regulate t'ne flow rate of the mi~ed fluid at -the desired tempera-ture. Addi-tionally, this invention can monitor the dispansed volume of the mix and can de-activate itself when a desired volume has been dispensed. Ano-ther object oE this invention is provide a visual quantified display of the tempera-ture, flow rate and/or volume of the fluid dispensed from the system.

To this end the inven-tion provides a panel with which the user operates a microprocessor and from which he obtains inEoxmation about the s-tatus of the system. Referring to Figure 1, a simple drawing of the control panel 1 is illustrated. This control panel comprises a grid 2 with a selector 3 which can be placed anywhere within -the confines of -the grid. One axis of the grid is for temperature selection and a quantified temperature range 4 is displayed alongside this axis. The other axis is for flow rate control and a quantified flow rate range 5 is displayed alongside this axis. The control panel also contains any number, probably ten or less r of pre-set selector buttons 6 which when activated dispense a pre-set volume of fluid at a pre-set temperature/flow rate combination and will override the grid selector and volume selector se-ttings. The pre-set selector buttons may also activate solely either a temperature/flow rate combination or a volume setting. The programmed settings are changeable by the user.

The control panel also contains a volume slide control 7 which when activated controls the volume oE the fluid to be dispensed.
The grid selector 3 and the volume slide control 7 also double as START command switches which when activated will begin -the fluid mix dispensing process. The control panel furthex con-tains a STOP
command button 8 which when activated overrides all other controls and shuts both valves.

S~3 The control panel also contains -visual numexical displays which indica-te the actual tempera-ture 9 and flow rate 10 of the Eluid as it is being dispensed and a visual 11 and/or audio signal which is activated by the control circui-t only while the fluid dispensed is not in accordance with what was selected. The con-trol panel also contains a visual numerical display 12 which inaica-tes the volume of fluid dispensed since the most recent START cornmand and ~olume instruckion was input to -the control panel.

Referring to Figure 2~ a schematic diagram of the invan-tion system i5 illustra-ted. The invention also provides a power ac-tuated valving system 13 which is comprised of two valves which couple to -the two fluid source pipes 14, one on one, with any -type of power actuated means to open and close the valves concurren-tly and independently of each other, and a pipe 15 which joins the two pipes exiting the valves into the pipe that carries the fluid to point of dispensing or use.

The invention also provides fluid status sensors 16 attached to the single outflow pipe 17 carrying -the mix. These sensor~ sense the tempera-ture, flow rate and volume of the Eluid mix as i-t passes through the pipe, and continuously, while the microprocessor is in operation, transmits this in~orma-tion to the microprocessor 19 and visual displays on the control panel via electrical wire relays~

The invention also provides valve status sensors 18 which sense when and whether each valve is either fully open or fully closed.
This informat.ion prevents the rnicroprocessor :Erom at-tempting to fulfill a cornmand not possible due to inadequate fluid supply of one tempe:ra-ture or the other or both.

The in~enl:ion also provides a microprocessor 19 which correlates the info.rmatio~ sent to it by the said 1uid status sensors to the respective lnstructions input by the user. The microprocessor adjusts -the power actuated valve drives electronically until the fluid s-tatus sensors indicate that -the condition of the dispensing fluid matches the conditions re~uired and selected by the user.
The microprocessor also adjusts the said valves continually as necessary to compensate for any subse~uent variances which may occur Erom the selected conditions. The microprocessor further adjusts the valves accordingly when -the user requires no more fluid.

The invention also provides, as a safety feature, a single manually operated valve 20 with which to regulate or stop the fluid flow at a point beyond the power actua-ted system.

DETAILED DESCRIPTION

The invention is suitable wherever hot and cold water are mixed and discharged from a fauce-t, showerhead or hose at a bathtub, sink, shower enclosure or like receptacle, for domestic, health-care, public, industrial, consumer or business purposes. With apparent slight modif.ications this invention is suitable for a broad range of industrial or small scale uses where the regulation of temperature and flow rate of the fluid discharge from a faucet, showerhead or hose at a bathtub, sink, shower enclosure or like receptacle by the reg~llation o:E the proportions of the mix oE two fluids of varying temperatures is desired, and lf further desired, to a speci:Eic volume.

Power to the systeml can be provided f.rom a conventional outlet, ` although a diract conn0c-t:ion to -the electr:ical sys-tem of the building may be more prudent. The power is applied to the microprocessor and -the device or devices which open a~d close -the two valves. The nature of these devices is irrelevant to this inven-tion provided certain characteristics are met. These are that the valves' opening and closing functions are smooth~ ~uick~ and precise and that the two valves are controlled independently of each other. Two suitable systems available are reversible electric motor driven valves and pneumatic driven valves. The activation oE
the valves is con-trolled by the microprocessor. The valves must be driven quickly and at just short of such a speed that would have the valves overshoot their optimum positions before the microprocessor can determine that these positions have been obtained.

An op-tional set-up would be to have a third valve in comunica-tion with the control circuit -to control -the flow rate after the fluid mix is adju.sted to the correct temperature by -the Eirst -two valves.

The microprocessor receives inputs from the control panel and from the fluid and valve status sensors. The function o~ the microprocessor ls to adjust -the valves so tha-t the fluid status sensor reaclings of the resultant Elow matches the instructions input Erom the control panel. Each valve can be opened or closed independently of the action or inaction of the other valve. A
safeguard in the system gives temperature control priority over flow rate control so -that an inabili-ty to reach a desired flow ra-te at a given temperature is no-t compensated for a-t the expense of losing the chosen temperature, the preferred -temperature will be maintained as closely as possible, iE necessary, at a reduced flow rate~

~9~

The microp:rocessor also, when ins-tructed to do so via the control panel, monitors the volume oE fluid dispensed and closes the valves when -the sensed volume dispensed matches the volume ins-t.ructions input via the control panel.

The microprocessor is comprised o circuitry such -that the functions as described in this text and illustrations in Figures 3~ 4, 5, and 6 may be performed. The microprocessor also transmits to the sensors, valve drive devices, and control panel, the appropriate electrical power and signals as each requires. The microprocessor also receives, uses, and relays to the display fluid status sensor information.

The electronic circuitry of the microprocessor performing the said functions will probably be embodied in the latest state of the art integrated circuit micro-chip form, but can be comprised oE more primitive electronic components.

The microprocessor perEorms three basic operations. These are th~
attaining and maintaining oE a Eluid mix of a desired temperature, at a desired flo~ rate, with monitoring of the volume dispensed, and termination of fluid flow when a desired volume has been dispensed or whenever instructed to termina-te by the user via -the control panel.

The microprocessor is the physical embodiment in circuit form oE
the logic illust:rated in Figures 3, 4, 5, and 6.

Referring to Figure 3, the logic diagram for tempera-ture and Elow rate control of the fluld mix is illustrated. The user first selects the desirecL temperature and flow rate of the fluid mix '75~3 either by plac:ing the seLec-tor to the appropria-te pos.ition on the cont:rol panel gr.id o:r bv touching one oE -the reprogrammable pre-set command buttons. If fluid is already flowing and the user .i.s mexely chan~ing -the temperature and/or flow rate the microprocessor will ir~nediately adjust the valves to match the new instructions. I-f~ however, the valves were closed/ no ac-tion will occur unti]. the user acti.vates the microprocessor by touching the START command button, o.r by pushing in or out the temperature/f.low xate selectox.

Once activated, the microprocessor continuously moni-tors all the sensors wi-thin the systemO

If the outflow temperature is less than that desired, the valves are adjusted accordingly and likewise if -the temperature exceeds that des.ired.
Vi.rtually simultaneously, a flow rate sensor reading is taken to determine whether the overall flow rate is greater or less than that desired and both valves are accordingly adjusted. The valves are almost continuously adjusted by the microprocessor during the operation of the system.

Referring to Figure 4, the logic diagram for volume control i5 illustrated. When a specific volume is re~uired, the user either slides a selector on the control panel to the desired volume se-tting or activates a pre-set command button. The microprocessor will, .if fluid is already flowing~ from the time of this most recent inst.ruction, monitor the Eluid dispensed, and when -the desired volume has been dispensed, it will shut off both valves.
As with -the temperature/flow rate control, no action will occur until the user activates the microprocessor with a START command.
The volume con-trol selector also doubles, if pushed in or ou-t, as a START swltch. Volume controL operation ls performed independently oE and concurrently wi-th the -temperature/flow rate con-trol process.

ReEerring to Figure 5, the logic diagram for the Elow s-top con-trol is illustra-ted. When -the user wishes -to -terminate the fluid flow, he simply activates the STOP command button and the microprocessor will shut both valves regardless of whether or not a previously selected volume has been dispensed.

Referriny to Figure 6, the logic diagram for the pre-set control is illustrated. The pre-set values and pre-set button input can be changed at any time by the user. They can command the microprocessor to perEorm both temperature/flow rate control and volume control operations or simply the former i a continuing flow is desired. Activation of a pre-set command also performs a START command.

Regarding sensor placement with the piping system, sensors could be located ahead of the valves in an attempt -to anticipate the result by calculation before -the 1uid is mixedO This can be achieved by one set oE 1uid sta-tus sensors for each of the two incoming pipes and modifying the microprocessor circuitry accordingly. However, the almost immeasurably small increase in control eficiency would probably not offset the increased cornplexity, hardware and cost oE such a system. The speed and accuracy of the invention operation as it would be performed in the embodiment described herein would be almost identical to the system with Eluid sensors in advance of -the valves, except in cases where the fluid supply is subject to sudden and large fluctua-tions of temperature or flow rate. In those cases the sensors should be located far enough in advance to allow -the con-trol clrcuit to adjus-t -the valves at the appropriate time. In the case where sensors are located in advance, it would be preferabl~ to have in addition post-mixing sensors, for precision o~ control and display of the flu.id conditions. The poin-t oE -the invention is that a microprocessor/ instructed by the user and while taking readings from sensors within the system, controls valves accordingly and advises the u.ser of the Eluid condition.

The advantages of this invention ove:r previous methods and devices are numerous. When applied to the operation oE filling a bathtub, the use.r simply touches a button and walks away. The tub will fill itself with water oE the user's selected temperature and then ~ill shut itself off when the user's preprogrammed volume has been dispensed.
This invention eliminates in all applications the need for visual observation or touch-testing by the user. The user need not wet his hands until the dispensed fluid is ready for use. Also eliminated is the need or continual monitoring and manual adjustment of faucets to correct tempera-ture and flow rate fluctuations from those preferred. This advantage can be particularly important where changing uses and demands elsewhere in the plumhing system cause a sudden change in the pressure oE
one or both of the two ingredient fluids. The invention operates to correct a resultant change in the temperature of -the mix and to prevent a drastic change in the temperature oE the discharged L luid.

Fluid and time are saved because of the much quicker method of attaining the desired temperature and flow rate combina-tions. The invention's interface with the user, the control panel, is inherently tidier in operation and appearance than faucets, and afEords easier clea;nin~.

~:19~

Control by pushbuttons, which can be touch or proximity ac-tivated, ls made possible in -this inven-tion and operation is thus much easier than by faucets ox plumbing levers. This is particularly advantageous for people who suffer from ar-thritis or o-ther physical disability.

The visual numerical displays of -the fluid condition assure the user -tha-t he i~ get-ting what he wants.

The audio signal, which activates while a signiEicant discrepancy exists between instructions and fluid conditions, advises the user of that discrepancy, as do the visual displays. A prolonyed audio signal indica-tas that probably the re~uested selection is not attainable at -tha-t time due to limitations in the Eluid source ~ystem.

An additional advantage is that the supply of water in consumer applications is upgraded to use state-of-tha-art technology and provide precise and automated control o~ this resourceO

The most obvious disadvantage is tha-t if power supply is disrupted, the system will not operate. In view of this a manually operated shutoff valve can be incorporated into the system, to provide manual override shutoff control. Additionally, a manually operated set of valves could be incorporated to bypass -the rest oE

the invention, to provide manual override supply con-trol.

Another optional f~ea-ture would be to incorporate a -timer to allow activation of -the system at a -time later than that of programming the user selections. With this arrangemen-t, the user could, for example, wake wp and irnmediately get into a full bath oE chosen - -tempera-tureO ~ ~ 9 ~59 3 The presen-t inven-tion may be embodied in other specific ~orms without departing from the spirit or essential characteristics thereof. The presen-tly disclosed embodiment is -therefore to be considered in all respec-ts as illustra-tive and not restric-t,ive, the scope of the invention being indicated by -the appended claims rather than by the Eoregoing descrip-tion, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

The embodiments of the invention in which an exclusive property or privelege is claimed are defined as follows:

l. Apparatus for automatically controlling the temperature of the discharge from a faucet, showerhead or hose at a bathtub, sink, shower enclosure or like receptacle, the apparatus comprising:

a) two valves for regulating respectively the flows of two similar fluids of differing temperatures supplied by two pipes, which attach to the valves, before the fluids are mixed for the said discharge;
b) drive means for controlling the valves concurrently and independently;
c) an electrical control circuit means for continually controlling the said drive means;
d) a means of sensing the open/closed status of the valves, said status sensing in communication with said control circuit;
e) a means of sensing the temperature(s) of the fluid(s) passing through the system, said temperature sensing means in communication with said control circuit;
f) an input means permitting user selection of a desired temperature of the mix of the two fluids, said input means in communication with said control circuit;
2. Apparatus as claimed in claim 1, including means for controlling the flow rate of the said discharge:

a) means for sensing flow rate or rates within the system, said flow rate sensing in communication with said control circuit;
b) input means permitting user selection of flow rate of fluid discharge, said input means in communication with said control circuit.
3. Apparatus as claimed in claim 2, including means for controlling the volume of fluid discharged from the system, with:

a) means for sensing the volume dispensed from the system, said volume sensing means in communication with said control circuit;
b) input means for user selection of volume of fluid to be dispensed, said volume input means in communication with said control circuit.
4. Apparatus as claimed in claim 2, or claim 3, in which a third valve, with drive means in communication with said control circuit, controls the flow rate after the mix of the fluids.
5. Apparatus as claimed in claim 1, claim 2, or claim 3, in which said apparatus is attached to plumbing for a water supply.
6. The control circuit in accordance with claim 1, in which communications from said sensing means are compared to input from said input means and signals are sent to activate said drive means so as to reduce the discrepancy.
7. The control circuit in accordance with claim 2, in which communications from said temperature and flow rate sensing means are compared respectively to input from said temperature and flow rate selection input means and signals are sent to activate said drive means so as to reduce the respective discrepancies, with priority to reducing the temperature discrepancy as far as possible before reduction of flow rate discrepancy.
8. The control circuit in accordance with claim 3, in which communications from said temperature, flow rate, and volume sensing means are compared respectively to input from said temperature, flow rate, and volume selection input means, and signals are sent to activate said drive means so as to reduce the respective discrepancies, with absolute priority to completion, that is, elimination of volume discrepancy, and priority to reducing temperature discrepancy as far as possible before reduction of flow rate discrepancy.
9. The apparatus of claim 6, claim 7, or claim 8, in which the control circuit includes a microprocessor.
10. The apparatus of claim 6, claim 7, or claim 8, in which the control circuit includes integrated circuit memory.
11. Apparatus as claimed in claim 1, claim 2, or claim 3, in which there is a display means to show input parameters.
12. Apparatus as claimed in claim 1, claim 2, or claim 3, in which there is a display means to show values that have been input.
13. Apparatus as claimed in claim 1, in which there is a display means to show the temperature of the said mix of the fluids.
14. Apparatus as claimed in claim 2, in which there is a display means to show the temperature and the flow rate of the mix of the fluids.
15. Apparatus as claimed in claim 3, in which there is a display means to show the temperature, the flow rate, and the dispensed volume since activation, of the mix of the fluids.
16. Apparatus as claimed in claim 1, claim 2, or claim 3, in which said input means is touch activated.
17. Apparatus as claimed in claim 2, or claim 3, in which said input means by means of coordinate scales permits one-touch selection of both temperature and flow rate.
18. Apparatus as claimed in claim 1, claim 2, or claim 3, in which said user selections are infinite within a range of respective possible values.
19. Apparatus as claimed in claim 1, claim 2, or claim 3, in which said input means includes changable pre-set selections.
20. Apparatus as claimed in claim 1, claim 2, or claim 3, in which said input means includes one-touch activation of the system.
21. Apparatus as claimed in claim 1, claim 2, or claim 3, in which said input means includes one-touch de-activation of the system.
22. Apparatus as claimed in claim 1, claim 2, or claim 3, including a timer for pre-set activation of the system.
23. Apparatus as claimed in claim 1, claim 2, or claim 3, in which said drives automatically shut off the valves in case of power failure.
24. Apparatus as claimed in claim 1, claim 2, or claim 3, in which said valves are connected to manual override means.
25. Apparatus as claimed in claim 1, claim 2, or claim 3, in which said system includes a third valve, manually operated, enabling the flow of the mix to be shut off.
26. Apparatus as claimed in claim 1, claim 2, or claim 3, including an audible or visual signal to broadcast a state of significant discrepancy between the temperature or flow rate input value selected and the respective temperature or flow rate of the mix of the fluid.