US3416162A - Automatic flushing control mechanism - Google Patents

Description

Dec. 17, 1968 M. w. HAMBLEN 3,

AUTOMATIC FLUSHING CONTROL MECHANISM Filed July 11, 1966 2 Sheets-Sheet 1 FIG.

FIG. 2

United States Patent 3,416,162 AUTOMATIC FLUSHIN G CONTROL MECHANISM Milton W. Hamblen, Seattle, Wash, assignor to Contamination Control Corporation, Seattle, Wash., a corporation of Washington Filed July 11, 1966, Ser. No. 564,371 6 Claims. (Cl. 4-100) This invention relates to an automatic flushing control mechanism for urinals, toilets, chemical waste disposal units, and the like. While the principles of the present invention may be used in a variety of applications requiring the generation of a control signal upon the occurrence of a predetermined change in the electrical properties of a liquid, it will be described below in the context of an automatic flushing control mechanism for a lavatory facility.

It is well known that people generally neglect to operate the flush valves of lavatory facilities in the rest rooms of public places such as factories, sports arenas, office buildings, etc. In schools, gymnasiums, and other places where young people congregate the problem is often the opposite, as repeated operation of the flush valve after a single use of the facility may be the more typical case. Accordingly, rest rooms in such places oftentimes employ a system providing automatic flushing of the lavatory facility at periodic intervals without regard to whether the facility has been used and a change of Water is required. Such an arrangement necessarily results in the needless Waste of a large quantity of water. In addition to the expense of this water wastage, there is also the consideration that, in several parts of this country and in many foreign countries, it is becoming more and more ldiflicult to obtain adequate amounts of water for residential and industrial uses, and therefore massive Water conservation measures are becoming increasingly necessary.

Automatic flushing mechanisms have been proposed in the past which are designed to economize on and prevent this Water usage by replacing the reservoir water in the trap or bowl of the lavatory facility only after use of the facility. One device of this type, known to the art, utilizes an electrode assembly situated in the trap or bowl of the urinal or other lavatory facility wherein any change in the specific gravity, and thus the electrical conductivity, of the water, due to contamination by other fluids or soluble foreign matter, unbalances a bridge circuit to thereby provide a control signal for actuating the flush valve of the facility. Such an arrangement is not entirely satisfactory because any change in the mineral content of the fresh water supplied to the lavatory facility, as a result of naturally-occurring variations in the local Water supply, may on occasion be effective to unbalance the bridge circuit, and either inhibit its proper operation or cause continuous flushing. Furthermore, elevation or sudden fluctuations in temperature may also cause the bridge circuit in such arrangements to spontaneously unbalance, thereby generating a false flushing control signal.

The present invention avoids the disadvantages of conventional automatic flushing mechanisms of the type described above by utilizing a pair of electrode assemblies situated at different points in the water flow system of the facility. One electrode assembly, designated the reference sensor, is located in the fresh water supply \line of the urinal or other lavatory facility. The other sensing element, the measuring sensor, is correspondingly positioned in the trap or bowl of the facility.

The respective electrode sensors are connected in opposing but otherwise identical arms of a Wheatstone bridge circuit which is balanced with fresh water in the facility, so that both electrode assemblies are sensing fluid mediums of identical composition. Thereafter, any contamination introduced into the tank or bowl of the ice facility will change the electrical conductivity of the water contained therein. However, since the conductivity of the fresh water in the supply line to the facility remains unchanged during this time, an imbalance will be created in the arms of the bridge circuit. The resulting flow of current between the neutra terminals of the bridge is then used as a control signal to actuate the flushing valve of the facility and thereby permit fresh water to circulate in the tank. Once the contaminated water is drained away and replaced with fresh water from the supply line, the balance in the bridge circuit will be restored, causing the flushing control signal to cut off, and the system restored to its initial condition.

The advantage of the system disclosed herein is that, since the conductivity of the tank water sensed by the measuring electrode is not compared to an absolute quantity but instead is referenced against the conductivity of the fresh water supply, any variation in the mineral content of the fresh Water supply will be automatically compensated for in the bridge circuit. In addition, any change in the electrical parameters of the circuit components due to temperature effects or deterioration will not affect the balance of the bridge since both arms of the bridge circuit contain identical components.

In a preferred embodiment of the present invention, the circuit for the automatic flushing mechanism is arranged so as to permit a plurality of lavatory units to be separately monitored and controlled, using only a single reference electrode sensor and power supply for the entire system of units. Any number of lavatory units can be readily added on, as desired, to the basic control circuit without affecting the operation or increasing the complexity of the system.

It is therefore a principal objective of the present invention to provide a novel and improved automatic flushing control mechanism for urinals and other lavatory facilities which initiates flushing action after the facility has been used and continues to circulate fresh water in the facility until the contaminating fluid or other soluble foreign matter has been removed.

It is another important objective of the present invention to provide an improved automatic flushing control mechanism, of the type comprising an electrode sensor in a Wheatstone bridge circuit, which is stable in operation and unaffected by changes in the mineral content oft-he fresh water supply or in the environmental temperature.

And it is another objective of the present invention to provide an automatic flushing control mechanism of the type described which permits a plurality of units to be readily added on and separately controlled from a central circuit Which requires only a single reference sensor and power supply for the entire system.

The foregoing and other objectives, features, and ad vantages of the present invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.

FIG. 1 is a side elevational view showing an embodiment of the present invention providing automatic flushing control of a urinal.

FIG. 2 is a top plan view of the urinal and control unit shown in FIG. 1.

FIG. 3 is a top plan view of a pair of urinal units whose flushing action is separately regulated by a modified embodiment of the automatic flushing control mechanism provided by the present invention.

FIG. 4 is an electrical schematic diagram of a suitable circuit embodiment for providing automatic flushing control of one or more lavatory units according to the present invention.

Referring now ti FIGS. 1 and 2, there will be seen a urinal 10 attached to a wall 12. At the top of the urinal is a water supply pipeline 14 in which is inserted a solenoidactuated flusher valve 16 of conventional design. A box 18 containing the control circuitry (FIG. 4) for actuating the valve 16 is mounted to the wall 12. The solenoid of the flusher valve 16 is connected via leads 17 to corresponding terminals 17a on the control box 18 which is energized with electrical power received from outlet 20 via cord 19.

At a suitable location in the supply pipe 14 for the urinal 10 is situated the reference electrode sensor 30 comprising a pair of exposed electrodes projecting in the flow path of the fresh water supply. A pair of lead-in wires 32 connect the reference sensor to corresponding terminals 32a on the control box 18.

In the bottom of the urinal is an exit pipeline 21 leading into a gooseneck 22 and thereafter into a discharge line 24. In the gooseneck 22 (or other suitable location in the trap of the urinal) is positioned the measuring sensor 40, similarly comprised of a pair of electrodes projecting into the fluid collected in the base of the gooseneck. Lead wires 42 from the measuring electrode sensor g connect to corresponding terminals 42a on the control In FIG. 3 the automatic flushing control mechanism housed in the control box 18 is shown regulating a pair of urinal units and 10' mounted on a common wall 12. In this modified embodiment, elements having the same reference characters as those shown in the embodiment of FIGS. 1 and 2 are identical, and those elements associated with the second urinal unit 10 are designated with a prime superscript. For separate control of two or more lavatory units, the arrangement is identical to that shown in the embodiment of FIGS. 1 and 2 except that the reference electrode sensor 30 is inserted in only one of the fresh water supply pipes 14 since the supply will be common for all of the urinal units. Each of the units 10, 10 has an associated measuring electrode sensor 40, 40' positioned in the gooseneck of its respective discharge line, and the flushing of each unit is individually controlled by the electrical circuitry housed in the common control box 18.

FIG. 4 shows an electrical schematic of a suitable control circuitry for providing automatic flushing action of the single or double urinal units shown in the embodiments of FIGS. 1-2 and 3, respectively. The circuit shown is capable of providing separate control of up to two lavatory units; however, as will be explained below, additional units can be readily incorporated onto this basic circuitry with a minimum of complexity and expense.

The circuit schematic, for purposes of explanation can be divided into three major portions: Power Supply Unit #1 Control; and Unit #2 Control. In the Power Supply portion of the control circuit, electrical energy is received via cord 19 from a suitable source of alternating potential E which may typically be on the order of 125 volts A.C. This voltage is applied to the primary P of a power transformer PT having secondary coils S and S In secondary coil S the alternating waveform is stepped up to a higher potential where one half-wave thereof is first rectified by a diode D and then smoothed by the filter network of R C to provide a direct-current potential E on the order of 170 volts DC The other half-wave of the waveform on the secondary S of the power transformer is tapped through a resistance-divider network R R rectified by diode D and then smoothed by a filter network R C to provide a relatively low direct-current potential E on the order of about 4 volts DC. The other secondary coil S of the power transformer PT supplies a small alternating voltage E of about 6.3 volts A.C. which, in addition to the function described below, may also be used to energize the heater elements (not shown) of the vacuum tubes employed in the control circuit.

Continuing on now to the portion of the electrical diagram designated Unit #1 Control, the alternating voltage E is applied across the opposing terminals W1, W2

ries with the terminals 42a which are connected to the measuring" electrode sensor 40 in the trap 22 of the first urinal unit. With fresh water in the lavatory facility, and with the sensors 30 and 40 being of identical construction and dimension, the currents flowing in the respective left and right-hand branches of the bridge W will be exactly equal, since the total resistance in the respective branches will be identical. Accordingly, in this balanced condition, there will be no net voltage difference appearing across the neutral terminals W3, W4 of the bridge circuit.

Under the above-described balanced state of the bridge circuit W, a negative bias voltage of magnitude E is applied to the grid of the vacuum tube T, by a biasing network comprised of the resistance-capacitance combination R C With this level of negative bias voltage applied to its grid, vacuum tube T is cut off, and no current flows in the plate circuit of the tube which is connected through the solenoid of relay RL to a B+ supply provided by voltage E In the cut-off state of tube T the contacts 60 of relay RL are in their normally-open condition and the flusher valve 16 of Unit #1 is disconnected from a source of energizing electrical power E However, when contamination is introduced into the fresh water collected in the trap of the first lavatory unit 10 (Unit #1), the conductivity of the current path between the electrodes of the measuring sensor 40 will be significantly changed. This in turn will alter the division of current between the respective branches of the Wheatstone bridge circuit W, causing a voltage differential to exist across the normally neutral terminals W W4. This difference potential, which is alternating in waveform, unblocks the diode D and causes the bias voltage established across the capacitor C to leak off. When the negative grid bias has been reduced to a predetermined level, the vacuum tube T will no longer be cut off, and current will start to flow in the plate circuit of the tube.

The flow of current in tube T energizes the solenoid coil of relay RL thus closing contacts 60 and connecting the solenoid of the flusher valve 16 on the first lavatory unit 10 to a source of energizing potential E Consequently (any contamination introduced into the first urinal unit 10 unbalances the Wheatstone bridge W and produces a control signal, in the form of plate current flow in vacuum tube T for actuating the flusher valve of the unit.

Upon actuation of the flusher valve 16, fresh water commences circulating in the lavatory unit, and the contaminated fluid is diluted and drained away through the discharge line 24. When the contaminated water has been again replaced by fresh water, the conductivity of the measuring electrode sensor 40 returns to its previous level, and the balance in the bridge W is restored. This restoration of bridge balance then blocks the discharge path for the biasing network R C and the capacitor C commences recharging to the negative bias level established by the voltage E whereupon the flow of plate current in the vacuum tube T is again out off.

Upon the cessation of plate current in tube T relay RL opens its contacts 60, and the actuation of the flusher valve for Unit #1 is terminated. The control circuit has then completed a full cycle of operation, and is ready for response following the next use of the lavatory facility. In this manner flushing action is commenced in Unit #1 each time the water reservoir in the trap of the unit is contaminated by fluids or other soluble foreign matter, and the flushing continues until the contaminated water is substantially replaced with fresh water from the supply line.

As previously mentioned, the control circuit shown in .nung the 170W of fresh when the V nve unit when actuated, of said Voile bridge circuit having said reference sponding assembly electrically connected in rst indicating branch thereof and having each of said hzeasurin 5 unit has be lectro assemblie respectively c nnected in orre ductivit spondin other branches thereolj (e) source of electrical potentia applie cross th two common terminals of said ran h in said NITED bridge circuit, 10

) electrical Inpedan ns 11 1d brid e circuit 1,404,155 1/ 1922 br alancing said bridge or each of the re ective 1,70 1083 4/1929 nits making the current flowing in each said 3101 1119 spectiv ranches corresponding to a respective unit 0241469 /1 962 ml to e current flowing in said first branch on- 15 3 115543 12/ 963 mg said reference electrode assembly, said bal- 31314, 081 /19 7 Atk COIIdJ ion occurri when th Water reservoir 3,373,449 1 usnok respective nit is composed substantially VERNE EI E "resh Wate and ectiv m: s erivrn spective con- 20 H K ART,

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Claims (1)

1. AN AUTOMATIC CONTROL MECHANISM FOR FLUSHING A LAVATORY FACILITY IN RESPONSE TO THE CONTAMINATION OF THE WATER THEREIN COMPRISING: (A) FIRST ELECTRODE MEANS SUPPLIED WITH FRESH WATER AND RESPONSIVE TO THE ELECTRICAL CONDUCTIVITY THEREOF, (B) SECOND ELECTRODE MEANS SUPPLIED WITH THE WATER IN SAID FACILITY AND RESPONSIVE TO THE ELECTRICAL CONDUCTIVITY THEREOF, (C) FLUSHING MEANS FOR PERMITTING THE FLOW OF FRESH WATER INTO SAID FACILITY WHEN ACTUATED, AND (D) OPERATING MEANS INCLUDING AN ELECTRICAL CIRCUIT CONNECTED TO SAID FIRST AND SECOND ELECTRODE MEANS FOR CONTINUOUSLY COMPARING THE CONDUCTIVITY OF THE FRESH WATER SUPPLIED TO SAID FIRST ELECTRODE MEANS WITH THAT OF THE WATER IN SAID FACILITY SUPPLIED TO SAID SECOND ELECTRODE MEANS, SAID OPERATING MEANS PRODUCING AN OUTPUT SIGNAL IN RESPONSE TO A VARIATION BETWEEN SAID CONDUCTIVITIES TO ACTUATE SAID FLUSHING MEANS.

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