Patent Application
20100175762
1. Field of the Invention
The present invention relates to interruptible power supplies for washing machines, and more particularly to a washing machine flood prevention system that interrupts power to the washing machine responsive to a control signal sent by a water level sensor in the event of an overflow
2. Description of the Related Art
Automatic washing machines often cause floods due to drain lines or drainage sinks, which collect periodic waste water, become obstructed or clogged, and overflow. Typically, the user of an automatic washing machine may not be in the vicinity of the washing machine when the drain standpipe or sink becomes clogged, thus allowing a substantial amount of water spillage on the surrounding floor area, which can cause damage to surrounding items and to the floor and covering. Such flooding is time-consuming and expensive to fix.
Thus, a washing machine flood prevention system solving the aforementioned problems is desired.
The washing machine flood prevention system provides an interruptible power supply to a washing machine. In the event of potential flooding by the washing machine, power to the washing machine is interrupted, and an alarm is delivered to the user.
The washing machine flood prevention system includes a control box housing a control circuit. The control circuit includes at least one alarm and a power outlet adapted for receiving the electrical plug of the washing machine. The alarm preferably includes an auditory alarm. Additional alarms, such as a visual indicator or a cellular transmitter for sending a wireless alarm signal to the user's telephone, may further be utilized.
A water level sensor, such as a float switch, is in communication with the control circuit. The water level sensor is adapted for mounting within a drainage sink associated with the washing machine and generates a control signal if the water level in the drainage sink rises above a certain level. A second, floor-mounted water sensor may also be utilized if the washing machine leaks water on the floor. Alternatively, when the washing machine drains into a standpipe instead of a sink, a water sensor may be mounted onto a discharge hose of the washing machine to generate a control signal if the drain standpipe becomes obstructed.
The control circuit preferably further includes a visual power indicator, a control switch for selectively activating and deactivating the control circuit, a reset switch, a switch for selectively activating and deactivating the alarm, at least one fuse, and a step-down transformer.
A ground fault circuit interrupter (GFCI) is in electrical communication with the control circuit. The ground fault circuit interrupter provides interruptible electrical power to the control circuit and the washing machine if a ground fault is detected anywhere in the circuit. The electrical power is interrupted if the control signal is generated by the water level sensor responsive to a flood. The alarm is further actuated in response to the control signal.
These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
As best shown in
Referring to
The control box 12 has an audible alarm 14, such as a bell, a buzzer, or other device that emits an audible alarm, mounted within the control box 12. The housing includes an outlet 16, to which a power cord C of washing machine W may be connected.
The control box 12 may also have several buttons, switches, and indicator lights mounted thereon. As shown in
The control box 12 may include a main power switch 22 to apply power to the primary control circuit. Power switch 22 may be a toggle switch, rotary switch, push button switch, or any suitable power switch. The control box 12 may have a start/reset switch 24, which is preferably a momentary push button switch, mounted thereon for silencing or turning off the alarms and applying power to the outlet 16. Finally, the control box 12 may optionally have a mute switch 26 for turning off any audible alarm while the user or a service technician attempts to locate and correct a fault condition.
Referring back to
For those washing machines W that include a drain tube P that discharges waste water into a sink S, the control unit 12 is connected to an external water sensor, such as normally closed float switch 40, that detects when the water level in the sink S rises above a predetermined water level. Alternatively, for those washing machines that discharge waste water directly into a drain standpipe, the system 10 may include an external, normally closed water sensor switch 43 attached to the discharge pipe P or other conduit to detect overflows that may occur, e.g., when the drain standpipe is clogged, the switch 43 being electrically connected to the control unit 12. Optionally, the system 10 may include a normally closed floor-mounted water sensor switch 41 connected to the control unit 12 for detecting flooding of the floor where the washing machine W is located.
The step-down transformer 32 steps the 120 volts applied to the transformer primary coil down to 24 volts at the transformer secondary coil. It will be noted that the symbol C shown inside a triangle in
The secondary circuit includes a first relay K1, which may be a double pole, single throw relay having a coil 36, one normally closed contact 38, and one normally open contact 39. One pole 37 of relay K1 is connected to the coil of a second relay, K2, described below. Pole 37 switches the normally open contact 39 to the closed position when the coil 36 is energized. The other pole 42 of relay K1 is electrically connected to the secondary coil of transformer 32 through fuse 34. Pole 42 switches the normally closed contact 38 to the open position when coil 36 is energized. Normally closed contact 38 is electrically connected to one or more of an audio alarm 14; a cell transmitter 15; and a visual alarm 20. Audio alarm 14 may be a bell, a buzzer, or any other audible device (with accompanying circuit, if needed) that can emit an audible alarm, and is mounted within control box 12. Optionally, mute switch 26 is connected in series with the audio alarm 14 so that the audio alarm 14 may be muted while the user or a service technician resolves a flooding or fault condition. The control unit 12 may optionally include cell transmitter 15 for transmitting a pre-recorded alarm message to voice mail by wireless telephony, or may be any other device for transmitting an alarm message or signal to a remote location. Visual alarm indicator 20 may be any device discussed above (with accompanying drive circuit, if needed).
The normally open pole 37 of relay K1 is electrically connected to the power-on visual indicator 18, discussed above. The normally open pole 37 is also connected to the coil 46 of a second relay K2. Relay K2 may be a double-pole, single-throw relay having coil 46, first pole 48, first normally open contact 50, second pole 52, and second normally open contact 54. The first pole 48 is electrically connected to outlet 16, and the first normally open contact 50 is electrically connected to primary fuse 30 so that when the coil 46 is energized, first contact 50 is closed and 120 volts is applied to outlet 16 to provide power for washing machine W.
The second pole 52 and second contact 54 of relay K2 form part of a latching circuit that keeps the coils 36 and 46 of relays K1 and K2 energized during normal operation. The second pole 52 is electrically connected to one side of momentary switch 24. The second pole 52 of relay K2 is also electrically connected to the normally open contact 39 of relay K1. Finally, the second pole 52 of relay K2 is also electrically connected to the coil 36 of relay K1 in series through first jack 56 and second jack 58. The second normally open contact 54 of relay K2 is electrically connected both to the opposite side of momentary switch 24 and to secondary fuse 34.
When power switch 22 is closed and switch 24 is closed momentarily, the coil 36 of relay K1 is energized, closing contact 39 through pole 37. This energizes the coil 46 of relay K2, closing contacts 50 and 54. When momentary switch 24 is released, coil 46 remains energized, since power now flows through the closed contact 54 and the jacks 56, 58 to coil 36, keeping contact 39 closed so that current continues to flow to coil 46. Hence, power remains applied to outlet 16, and the coil 36 of relay K1 also remains energized.
The first jack 56 is a quick-disconnect male-to-female jack. An external sensor switch, either a normally closed float switch 40 or a normally closed drain switch 43, is connected-to the first jack 56 by a mating plug or connector. The effect is to place a normally closed switch, either float switch 40 or drain switch 43, in series between the second pole 52 of relay K2 and the coil 36 of relay K1.
Similarly, the second jack 58 is also a quick-disconnect male-to-female jack. An external sensor switch, normally closed floor switch 41, is optionally connected to the second jack 58 by a mating plug or connector. The effect is to place a normally closed switch in series between the first jack 56 and the coil 36 of relay K1.
In operation, the control box 12 may be mounted on a wall near the washing machine W. The washing machine is plugged into outlet 16. Depending upon the existing waste water discharge set up, a float switch 40 attached to the sink S or a drain switch 43 attached to the drainpipe P by the standpipe, and is connected to the first jack 56 quick-disconnect coupler by a suitable cable. Optionally, a floor-mounted water sensor switch 41 is connected to the second jack 58 quick-disconnect coupler, also by a suitable cable. The GFCI plug 28 is used to connect the control box 12 to the a.c. mains 27, and the GFCI plug reset button is pressed. Power switch 22 is then turned on.
At this point, no power is available at the outlet 16 to power washing machine W. Current flows through the primary coil of transformer 32, inducing a voltage in the secondary coil of the transformer 32, which appears at the open contact 54 of relay K2, while 120 volts appears at the open contact 50 of relay K2. However, current does flow through the secondary coil of the transformer through the pole 42 of relay K1 and the normally closed contact 38 of relay K1 to apply power to visual alarm indicator 20, cell transmitter 15, and audio alarm 14. The power-on visual indicator is off, since the coil of relay K1 is not yet energized and contact 39 is still open. Thus, the control box 12 now shows an alarm-activated state, which is normal upon initial power up.
In order to clear the alarm activated state and place the system into normal operation, the reset button on the GFCI plug 28 is pressed and then the start/reset button 24 is pressed for about 0.5 seconds. When button 24 is pressed, current flows from the secondary coil of the transformer 32 through the switch 24, the first jack 56 and normally closed switch 40 or 43, through the second jack and normally closed switch 41 (when so equipped), and through the coil 36 of relay K1. This closes the normally open contact 39 while opening the normally closed contact 38. Power is removed from the visual alarm indicator 20, cell transmitter 15, and audio alarm 14. At the same time, power is applied to the power-on visual indicator 18, and to the coil of relay K2, closing the normally open contacts 50 and 54. Power is applied to outlet 16 so that the washing machine W may be used, power-on visual indicator 18 turns on, and all alarms are turned off. The relay K2 latches through contacts 54 and 52, keeping the control circuit in this state indefinitely.
This condition continues until one of the water sensor switches 40, 41 or 43 opens (removing power from the coil 36 of relay K1 and the coil of relay K2, re-applying power to the alarms, turning off power to the washing machine W, and again placing the control box 12 in the alarm-activated state), or until a fault trips the GFCI plug, or power is otherwise removed from the control box 12. Power will not be re-applied to the washing machine W until the flooding condition or ground fault is corrected, the reset button on the GFCI 28 is pressed, and momentary switch 24 is pressed for about 0.5 seconds.
The system 10 is a fail safe system, since it uses normally closed switches to detect flood or overflow conditions and automatically shuts down power to the washing machine whenever the switches are cut, broken, activated, or opened for any reason. It will be understood that the system 10, although described with respect to a washing machine might also be used with a hot tub, sauna, or other appliance where flooding or overflow might occur. It will further be understood that the embodiments of the invention disclosed herein are exemplary, and other circuit configurations may be used in lieu thereof. For example, in some embodiments triacs or transistor switches may replace the mechanical relays in the latching circuit.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
