Water shut-off valve assembly

A hydraulically actuated shut-off valve is controlled by a solenoid actuated control valve. A flow detection unit having a substantially vertical inlet and a substantially vertical flow passage has a substantially horizontal outlet connected to the horizontal inlet of the shut-off valve. A member movable by water flowing through the flow passage actuates a switch forming a part of the flow detection unit. A control box preferably mounted on the flow detection unit has a timer and a reset switch therein which are capable of sending electrical control signals to the solenoid actuator of the control valve. The timer senses the condition of the flow detection switch and upon sensing that the switch has been closed a predetermined period of time suggesting abnormal water flow, possibly due to a leak in the system, sends a signal to the solenoid to actuate the control valve to cause the shut-off valve to close, preventing further water flow. The reset switch sends a reverse signal to the solenoid to cause the shut-off valve to open.

TECHNICAL FIELD 
This invention is concerned with apparatus for detecting abnormal water 
flow in a water supply system such as might be occasioned by a leak in the 
system or an outlet having been inadvertently left open. The invention is 
particularly concerned with providing relatively inexpensive, but 
reliable, apparatus suitable for use in an ordinary household residential 
unit. 
BACKGROUND ART 
It has previously been recognized that water flow through an ordinary 
household residential unit system is intermittent and that normal needs of 
the household are met by flows rarely exceeding periods of time measured 
in minutes. Water requirements for dish and clothes washing appliances are 
normally satisfied with interval water flows of two or three minutes and 
tub and shower bathing rarely requires a flow of water in excess of 10 
minutes. Thus, when water flows continuously through the system for an 
extended period, say one or two hours, this is usually abnormal and is an 
indication that there is a leak in the system or someone or something has 
neglected to close an outlet valve. And, of course, such abnormal flow is 
highly undesirable because flooding of portions of the household can 
result in considerable damage to the structure and to its contents. 
Prior inventors have devised water shut-off systems in which a valve was 
closed to terminate the flow of water into the household if there occurred 
a period of continuous flow of water exceeding a predetermined period of 
time. For example, Donald C. Aldrich in his U.S. Pat. No. 4,589,435, 
granted May 20, 1986 for "WATER SHUTOFF VALVE", discloses a valve for 
terminating flow of water in a residence in response to continuous flow of 
water therethrough for a predetermined period of time. The apparatus 
disclosed, however, employs fairly expensive components, such as a disk 
gate valve and an electronic sensor probe and circuit. The apparatus there 
disclosed exhibits the further disadvantage of allowing the water to again 
commence flowing if power is interrupted after shut off even though the 
leak in the system may not have been repaired. 
U.S. Pat. No. 4,518,955, granted May 21, 1985 to Knut Meyer for "METHOD AND 
APATUS FOR DETECTING LEAKAGE IN A FLUID CONDUIT SYSTEM", discloses a 
very complex flow detection system utilizing a microcomputer to monitor 
the time flow takes place, the duration of the detected flow, the 
intensity of the detected flow, and information about what fluid drains of 
the conduit system are closed. This system simply is uneconomical for an 
ordinary household. 
And Van de Moortele in his U.S. Pat. No. 4,522,229, granted June 11, 1985 
for "SAFETY DEVICE FOR WATER-PIPES", discloses a completely 
hydromechanical safety device for terminating unwarranted water flow. 
Again, the device appears to be too complex and costly for household use. 
There continues to be a need for an inexpensive, but reliable, system and 
apparatus for shutting off the flow of water in a residence in the event 
abnormal flow conditions are encountered. 
SUMMARY OF THE INVENTION 
This invention utilizes a normally open, hydraulically actuated, shut-off 
valve which can be controlled by a low voltage solenoid actuated control 
valve. The shut-off valve preferably has generally horizontal inlet and 
outlet flow passages. Connected to the inlet of the shut-off valve is the 
horizontal outlet of a flow detection unit having a generally vertical 
inlet and a generally vertical flow passage in which is positioned a 
vertically movable switch actuating member. A flow switch associated with 
the flow detection unit is connected to a timer which measures each period 
of time the flow switch is closed by virtue of water flowing through the 
flow detection unit to the shut-off valve. If the timer detects that the 
flow switch has been closed for a continuous predetermined period, the 
timer sends a signal to the solenoid actuated control valve to cause the 
shut-off valve to be closed. A reset switch is provided to send a reverse 
signal to the solenoid actuated control valve to cause the shut-off valve 
to be opened after the abnormal condition has been corrected. 
For convenience, the several components of this invention can be 
incorporated into an assembly in which the timer and reset switch are 
carried in a control box mounted atop the flow detection unit adjacent the 
shutoff valve or at a remote location. Manual actuators for adjusting the 
period of time of response of the timer and for manipulating the reset 
switch can be displayed on a control panel forming a part of the control 
box.

BEST MODES FOR CARRYING OUT THE INVENTION 
Referring particularly to FIGS. 1 and 2, the shutoff valve assembly of this 
invention in one of its preferred modes comprises a shut-off valve 11, a 
flow detection unit 12, and a control box 13. 
Shut-off valve 11 is of a normally open, hydraulically actuated type, the 
construction of which is best illustrated in FIG. 2. Valve 11 is comprised 
of a body portion 14 having a horizontal inlet 16 and a horizontal outlet 
17 communicating respectively with a valve chamber 18 which is completed 
and closed by a cover 19. The cover 19 of shut-off valve 11 is clamped in 
fluid tight engagement with the upper surface of valve body 14 by means of 
a series of screws 21 disposed about the periphery of the cover. Clamped 
between the cover 19 and the valve body 14 is the peripheral edge of a 
diaphragm 22. Diaphragm 22 is made of a thin sheet of elastic material, 
such as rubber, neoprene or like material. Diaphragm 22 divides valve 
chamber 18 into upper and lower sections, designated 27 and 28, 
respectively. Carried on a central region of diaphragm 22 is a closure 
member 23 having a resilient insert 24 adapted to seat against and seal 
valve seat 26 formed in the valve body 14 at the entrance to chamber 18. 
Valve closure member 23 is mounted on the underside of diaphragm 22 by 
means of a grommet 29 and guide screw 30 both of which have a passageway 
32 therethrough providing limited communication between the upper and 
lower sections 27 and 28 of valve chamber 18. A helical metal spring 31 
disposed between grommet 29 and the upper wall of cover 19 biases closure 
member 23 downwardly toward valve seat 26. If desired, a pin 33 mounted in 
the upper wall of cover 19 and extending down through passageway 31 may be 
employed to guide the movement of closure member 23 and to assist in 
keeping passageway 31 clear of the buildup of salts which may be deposited 
from water passing through valve 11. 
Opening and closing of valve 11 is controlled by a solenoid actuated 
control valve indicated generally by reference numeral 34 and mounted atop 
valve cover 19. Control valve 34 comprises an axially movable valve stem 
36 having an elastic insert 37 adapted to seal against a seat 38 formed in 
valve cover 19. The control valve 34 is closed when insert 37 seals 
against the seat 38 and is opened when the insert is lifted clear of seat 
38. Valve stem 36 is made of magnetically attractable material so that the 
stem functions as an armature within solenoid coil 39. A low voltage 
current flowing through coil 39 causes stem 36 to be raised to open the 
control valve or lowered to close the control valve, depending upon the 
direction of current flow through the coil. 
Control valve 34 preferably is of a self-latching variety in which valve 
stem 36 is capable of being releasably restrained in the position, either 
raised or lowered, to which it is moved by the magnetic forces from 
solenoid coil 39. In the valve shown in FIGS. 1 and 2, this latching 
function is performed by a permanent magnet 40 surrounding valve stem 36. 
Magnet 40 is preferably formed of a sheet of vinyl plastic material 
heavily impregnated with a ceramic magnetic material. Magnet 40 functions 
to attract valve stem 36 and releasably hold it in the position in which 
it is driven by solenoid coil 39. The magnetic forces generated by coil 39 
are sufficient to overcome the attraction of magnetic 40 to move stem 36. 
Control valve 34 functions to control movement of closure member 22 of 
shut-off valve 11 by controlling the flow of fluid through a vent passage 
41 providing a connection between the upper section 27 of valve chamber 18 
and the valve outlet 17. 
Valve 11 is caused to assume the open condition illustrated in FIG. 2 for 
the free flow of water from inlet 16 to outlet 17 by virtue of control 
valve 34 assuming the condition also shown in FIG. 2 in which its central 
valve stem insert 37 is held away from seat 38 to open vent passage 41. In 
this condition of the valve components any fluid, i.e., air or liquid, 
flowing into the upper section 27 from the lower section 28 of valve 
chamber 18 is permitted to bleed off or escape through passage 41. By 
virtue of the restricted flow between lower chamber section 28 and upper 
chamber section 27 afforded by passageway 31 a pressure differential is 
built up across diaphragm 22 causing the diaphragm to lift closure member 
23 and its insert 24 away from seat 26. The shut-off valve 11 in this 
condition is open. 
Valve 11 is caused to assume a closed condition under control of control 
valve 34 when the latter is energized to cause valve stem 36 to move 
downwardly so that its insert 37 seals against seat 38 closing off flow 
through vent passage 41. With vent passage 41 closed, fluid cannot escape 
from upper section 27 of chamber 18 and the fluid pressure acting on 
opposite faces of diaphragm 22 rapidly equalizes, allowing spring 32 to 
move closure member 23 and its insert 24 downwardly into sealing contact 
with shut-off valve seat 26 stopping the flow of liquid through valve 11. 
It can thus be seen that actuation of shut-off valve 11 is effected 
hydraulically with water pressure available from water supplied to the 
valve. This actuation can be controlled with a small, simple control valve 
34 capable of being actuated by a low voltage and low wattage solenoid 
system consisting of coil 39 and valve stem 36. The electrical energy 
required for actuation of shut-off valve 11 is quite small and the 
electrical components for supplying energy are quite small and 
inexpensive. 
It will also be appreciated that the principal components of shut-off valve 
11, namely the body portion 14 and the cover 19, can be inexpensively 
molded of plastic materials. 
In accordance with this invention, shut-off valve 11 is actuated in 
response to time periods of water flow therethrough. The invention thus 
requires means for detecting the flow of water through shut-off valve 11 
and this function is fulfilled by the flow detection unit 12 which is 
connected to the inlet 16 of the shut-off valve. Unit 12 comprises a body 
portion 42 having formed therein a substantially vertical inlet 43, a 
substantially vertical flow passage 44, and a substantially horizontal 
outlet 45. Flow of water through unit 12 is sensed by a vertically movable 
flow sensing and switch actuating member 46 mounted for sliding movement 
on a guide pin 47 depending from a closure plug 48 at the upper end of the 
flow detection unit. 
With water flowing through unit 12, the movable flow sensing member 46 
moves upwardly to the position shown in FIG. 2. In this position, a magnet 
49 embedded in the side surface of member 46 is brought into close 
proximity to a magnetically actuatable reed type flow switch 51 carried in 
closure plug 48 and causes that switch to close. With cessation of water 
flow through unit 12, member 46 descends by gravity separating magnet 49 
from switch 51 and allowing the latter to open. The opening and closing of 
switch 51 provides an electrical signal representing the cessation and 
resumption, respectively, of water flow through flow detection unit 12 and 
shut-off valve 11. This signal is transmitted via leads 52 to the control 
circuitry located in control box 13 mounted atop unit 12. 
The control circuitry contained within control box 13 is shown 
schematically in FIG. 3 and performs two basic functions. The first 
function is the measurement of the length of each period of time water is 
flowing through unit 12, i.e., each period switch 51 is closed, and to 
signal solenoid valve 34 to cause shut-off valve 11 to close if any such 
period exceeds the predetermined time period for which the control circuit 
is set. The second function of the control circuitry is to provide for 
manual initiation of a reset signal to be sent to solenoid valve 34 to 
cause shut-off valve 11 to reopen. 
The control circuitry includes a source of power (shown only schematically 
in FIG. 3) supplying electrical current to lines 53 and 54. The electrical 
energy is preferably in the form of direct current in a voltage range of 
from 12 to 24 volts. A main on/off line switch 55 is preferably provided 
in line 53 to permit the system to be temporarily rendered ineffective in 
situations where a very long continuous flow of water through the system 
is desired, such as, for example, to fill a swimming pool. A light 
emitting diode 54 may be connected across lines 53 and 54 after the line 
switch 55 to indicate whether the control circuitry has power. 
The means for measuring the length of the periods of time flow switch 51 is 
closed is a timer 57 connected in series with switch 51 across lines 53 
and 54. Timer 57 automatically resets itself to zero each time switch 51 
is opened and commences its time measurement each time there is a closure 
of switch 51. Timer 57 includes means, such as knob 58, for adjusting the 
time period of water flow which is not to be exceeded. An adjustable range 
of from about 10 minutes to about four hours will ordinarily meet the 
needs of most households. 
When timer 57 detects that flow switch 51 has been closed for the time 
period for which it has been set it emits a signal over lead 59 to the 
gate of a MOSFET transistor 60. Such a signal supplied to the transistor 
60 causes the transistor to conduct establishing a circuit from power line 
54, over lead 61, through a normally closed contact 62 in a relay 63, 
through a lead 64 to solenoid valve 36, thence back through lead 65 to 
another normally closed contact 66 and then through leads 67 and 68 to 
line 53. The coil 39 of solenoid valve 34 is thus energized to cause valve 
stem 36 to move to its closed position to initiate closure of shut-off 
valve 11 as explained previously. 
Closure of shut-off valve 11 may also be manually initiated by means of a 
water off switch 69 which is manipulated by a push button 70 on the 
control panel 71 of control box 13. Switch 69 simply connects the gate of 
transistor 60 directly to line 53 causing solenoid control valve to be 
energized. 
The means for resetting the shut-off valve assembly for normal operation 
includes a reset switch 72 in the control box 13. Reset switch 72 is 
manually actuated by a push button 73 on control panel 21. Closure of 
reset switch 72 establishes a circuit through the actuating coil 74 of 
relay 63 closing normally open contact 76 to connect solenoid valve lead 
65 to line 54 and closing normally open contact 77 to connect solenoid 
valve lead 64 to line 53 via lead 68. The direction of signal current flow 
through leads 64 and 65 to solenoid valve 34 caused by the closure of 
reset switch 72 is the reverse of the signal current supplied to valve 34 
by either the timer 57 or the water off switch 69. This reverse signal 
current causes solenoid coil 39 to generate magnetic force to move valve 
stem 36 upwardly opening vent passage 41 and causing shut-off valve 11 to 
open. 
It is to be noted that all of the controls to the shut-off assembly, namely 
the timer adjustment knob 58, the on/off switch 55, and push buttons 70 
and 73, together with the power indicator LED 56, are conveniently located 
on the control panel 71 of control box 13. If desired, however, the 
control panel 71 with the controls thereon can be placed at a location 
remote from the shut-off valve 11. Such an installation might be warranted 
where the shut-off valve 11 is required to be installed in a relatively 
inaccessible location, such as in a crawl space beneath the house. 
From the foregoing, it should be apparent that this invention provides a 
relatively inexpensive, but reliable, solution to the problem of shutting 
off the flow of water through a system which has experienced abnormal flow 
conditions. By employing a hydraulically actuated shut-off valve 11, 
control of that valve can be effected by a simple, low voltage solenoid 
control valve 34 which, in turn can be energized from simple, low-voltage, 
low-cost control circuitry. The flow detection unit 12 employs a simple 
flow and gravity actuated switch actuating member also contributing to the 
low cost and reliability of the assembly.