Automatic proximity faucet with override control system and method

A hands-free device includes a sensor, a motor, a pilot valve, a gear train, an arm, and, an override control. The pilot motor opens the pilot valve when an activation signal is received from the sensor. The arm is coupled to the gear train, and the override control is coupled to the arm. The override control is capable of moving the arm between a locked and unlocked configuration.

FIELD OF THE INVENTION

This invention relates to a system and a method that controls fluid flow, and more particularly, to a system and a method that controls fluid flow through a faucet.

BACKGROUND

Some faucets suffer from the effects of cross-contamination. The transfer of germs from one user to another can occur when a user touches a handle that enables the flow of water. Cross-contamination may result from hand-to-mouth, hand-to-nose, and hand-to-eye contact. An awareness of such contamination can create a reluctance to touch a fixture, which does not promote or preserve good hygiene.

To minimize the risk of transferring germs, some faucets use hands-free methods to control water flow. In these systems a passive sensor is used to detect a user. Once a user is detected, water flows for a fixed period of time.

A problem with some hands-free faucets is their inability to be turned on or off or to sustain a continuous water flow when a user is not detected. Because all sources of water possess naturally occurring contaminants, sometimes it is necessary to flush faucets and waterlines. Requiring a user to stand in front of a spout to flush a hands-free faucet can be time consuming and costly. The short periods of time that these hands-free faucets allow continuous water flow can also be inadequate as short periods of uninterrupted water flow will not always purge faucets of contaminants. Ironically, some automatic faucets used to prevent the spread of germs are more difficult to purge of water borne bacteria because a user is required to normally cause flow.

SUMMARY

The present invention is defined by the following claims. This description summarizes some aspects of the presently preferred embodiments and should not be used to limit the claims.

A hands-free embodiment comprises a sensor, a motor a pilot valve, a gear train, an arm, and an override control. Preferably, the motor opens the pilot valve when an activation signal is received from the sensor. Preferably, the arm is coupled to the gear train, and the override control is coupled to the arm. In one embodiment, the override control is capable of moving the arm between a locked and unlocked configuration.

Further aspects and advantages of the invention are described below in conjunction with the presently preferred embodiments.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

The presently preferred system and method provide users with a hands-free system and method for controlling fluid flow through a spout. The preferred system and method allows for continuous flow without actuating a handle or a button. In one embodiment an override control can turn on a faucet and/or sustain a continuous flow even when a user is not detected. A continuous flow through a spout will flush a faucet and can eliminate contaminants.

FIG. 1shows a front view of a hands-free embodiment. The embodiment comprises a spout102, a valve housing104, and a mixing housing106. Preferably, the spout102directs and/or regulates the flow of a fluid from a reservoir such as a pipe or a drum. The mixing housing106, positioned below the spout102, includes multiple fitting illustrated as male compression fitting emanating from about the nine, twelve, and three o'clock positions of the mixing housing106.

Preferably, the hands-free embodiment includes a sensor. When the sensor detects a user, an activation signal initiates continuous fluid flow. When the sensor no longer detects a user, the hands-free embodiment shuts off fluid flow which reduces the possibility of accidental flooding when the hand-free system and method are not in an open mode.

As shown inFIG. 1, the spout also comprises the sensor108. The sensor108can be a proximity, motion, an infrared, or a body heat sensor, and/or any other device that detects or measures something by converting one form of energy into another (e.g., into an electrical or an optical energy, for example). Preferably, the sensitivity range of the sensor108is adjustable. In one embodiment, the sensor108comprises logic that conditions the activation signal and automatically adjusts to its surroundings. In this embodiment, the sensor108can compensate for changes in its environment including changes in humidity, temperature or contact with objects such as wet paper towels, for example, and still maintain a desired sensitivity. Although the illustrated sensor108also functions as a spout102, the sensor108can be a separate element positioned adjacent to or away from the spout102.

Preferably, an outlet110couples the valve housing104to the spout102. As shown inFIGS. 1 and 3, at one end an aerator112is threaded to the spout102. The aerator112maintains fluid pressure by mixing air into the fluid. At another end, a threaded fitting couples the spout102to a surface114. In this embodiment, the spout102can have many shapes. Besides the rectangular and circular cross-sections that are shown, the spout102encompasses many other designs that vary by shape, height, accessories (e.g., use of built in or attachable filters, for example), color, etc.

Preferably, there is little resistance to the flow of fluids through the spout102. As shown inFIG. 2, fluid can flow through the entire interior volume202of the spout102. In an alternative embodiment, fluid can flow through a portion of the spout102. As shown inFIG. 3, fluid flow is restricted to a pipe302such as a copper tube or rubber hose enclosed by the spout102. Preferably, a spout bracket304couples the pipe302to the spout102. The spout bracket304can form a portion of the lower arcuate surface of the spout102.

Referring toFIGS. 4–6, the valve and mixing housing104and106can comprise a unitary housing or separate housing assemblies joined by straps and secured by the cover screws. Preferably, an override control402is coupled to the valve housing104. In one embodiment, the override control402is a mechanism that activates and/or sustains fluid flow. In another embodiment, the override control is a mechanism or logic that can activate or prevent fluid flow, and/or allow continuous fluid flow beyond a predetermined or programmed period initiated by an output of the sensor108.

Preferably, the mixing housing106encloses a mixing valve602. Preferably, the mixing valve602blends fluids from more than one source. In this embodiment, hot and cold water are blended to a pre-set temperature. Although no adjustments are shown, some embodiments allow a user to preset, or adjust, the temperature of the water being dispensed from the spout102.

Preferably, the mixing housing106is coupled to the valve housing104by a valve adapter502. As shown, the valve adapter502comprises a cylinder having a keyway702and threads704at one end as shown inFIG. 7. When secured to the valve housing104, a valve pin706seats within the keyway702providing a seal between the valve housing104and the valve adapter502. An O-ring708preferably provides a positive fluid tight seal between the valve housing104and the valve adapter502. An axial filter710can be disposed within the valve plug502to separate fluids from particulate matter flowing from the mixing valve602to the valve housing104or valve assembly. The filter710shown infigure 7comprises a mesh or a semi-permeable membrane. In another embodiment other materials that selectively pass fluids without passing some or all contaminants can be used as a filter.

As shown inFIG. 6, the valve housing104encloses a motor604. Preferably, the motor604is mechanically coupled to a cam606. In this illustration, the cam606is the multiply curved wheel mounted to the motor604through a shaft and gear train712. Preferably, the cam606and a cam follower608translate the rotational motion of the shaft into a substantially linear displacement that opens and closes a diaphragm610. In this embodiment the cam606has an offset pivot that produces a variable or reciprocating motion within a cutout portion612of the cam follower608. The cam follower608shown in the “P-shaped” cross-section is moved by the cam within an orifice, which engages a rod like element. Preferably, the rod like element comprises a pilot614that slides through an orifice616. Movement of the pilot614can break the closure between the inlet618and the outlet port620by moving the diaphragm610.

A bias plate622couples the diaphragm610to the pilot614. The bias plate622illustrated in a rectangular cross-section with projecting legs at its ends distributes the axial pressure of the pilot614across an inlet surface of the diaphragm610. Preferably, the diaphragm610is coupled between the legs of the bias plate622by a connector624. In this embodiment the connector624comprises a threaded member. In another embodiment the connector624comprises an adhesive or a fastener.

As shown inFIGS. 6 and 8, when the valve mechanism is closed, the diaphragm610seats against a seating ring or seating surface802which seals the inlet port618from an outlet port620. When closed, the fluid and the pilot614exert a positive pressure against the diaphragm610which assures a fluid tight seal. When the pilot pressure is released the fluid pressure acting on the underside of the diaphragm610exceeds the seating pressure of the fluid pressing against the inlet surface of the diaphragm610. When the pressure is greater on the underside than that on the inlet side, the diaphragm610is forced up which opens the valve and allows for a continuous angled fluid flow. When a pilot pressure is re-exerted, a fluid backpressure builds up on the inlet surface of the diaphragm610. Preferably, the pilot and fluid backpressure force the diaphragm610to seat, which in turn, stops the flow. The build up of backpressure preferably occurs after the sensor no longer senses an appendage such as a hand, when the hands-free embodiment is in an automatic mode.

As shown inFIGS. 6 and 8, the diaphragm610, which is the part of a valve mechanism that opens or closes the outlet port622, is wedge shaped. Some diaphragms610, however, can have a uniform thickness throughout or have many other shapes depending on the contour of the seating surface.

FIG. 7shows a top exploded view of the valve assembly. A housing104encloses a pilot valve assembly714and logic716. In this embodiment, the logic716interfaces the sensor108to the motor604. A compression of a molding718that outlines the lower edges of the housing cover720causes a fluid tight seal to form around the inner and outer edges of the housing104. Preferably, orifices722passing through the sides of the housing cover720allow power to be sourced to the logic716and the motor604. While battery packs can provide the primary power in this embodiment, hardwired alternatives with or without battery backups can also be used. Preferably, low-voltage direct current power supplies or battery packs drive a Direct Current motor and the logic.

The pilot assembly714of the hands-free embodiment shown inFIG. 7is preferably comprised of the motor604, its shaft, the cam606, the cam follower608, the gear train712, and the pilot614. Preferably, the O-ring626shown inFIG. 6makes a fluid tight seal between the motor664, its shaft, the cam606, cam follower608, the gear train712and a portion of the pilot614. Preferably, the seal is located approximately three quarters down the length of the pilot valve assembly714.

Preferably, the hands-free embodiment also includes an override control402that allows for continuous fluid flow. The override control402shown inFIG. 7is comprised of an override arm724. The override arm724is fitted to a stem726comprised of a cylindrical projection connected to an outward face of one of the interconnected gears that form the gear train712. In this embodiment, the stem726is a part of a spur gear728having teeth radially arrayed on its rim parallel to its axis of rotation.

Preferably, a strike plate730is coupled to the spur gear728by a shaft732that transmits power through the gear train712to the pilot614. As shown, the strike plate730can interrupt the rotation of the shaft732and gear train712when the pilot614reaches a top or a bottom limit of travel. Preferably, contact between the stem726and the convex surfaces of the strike plate730establish the top and bottom limits of travel. At one end, the stem726strikes a positive moderate sloping side surface734of the strike plate730and at another end the stem726strikes a substantially linear side surface736.

Preferably, an override knob738shown infigure 7is coupled to an override shaft724projecting from the override arm. In this embodiment, when the override knob738is turned counter-clockwise, the gear train712rotates until a projection740on the override arm724strikes stem726the strike plate730. In this position, the pressure on the underside of the diaphragm610will be greater than that on the inlet side, and the valve will be open.

While some embodiments encompass only an open and an automatic mode,FIG. 7shows a hands-free embodiment that also encompasses a closed mode. In this mode, the valve is closed and the motor604will not respond to the sensor108. While such a control has many configurations, in one embodiment this control can be an interruption of the ground or power source to the motor604by the opening of an electronic, mechanical, and/or an electro-mechanical switch. Only a turning of the override knob738to the automatic or open mode will allow fluid to flow through the outlet port620.

As shown inFIG. 9, the operation of the open mode begins when an open selection is made at act902. Once selected, fluid flows unaffected by any pre-set or predetermined periods of time. Fluid flow is shut off by either an automatic or manual selection at act904. In a manual mode, the detection of a user biases the motor to rotate the gear train712which is already in an open position. When a user is no longer detected, the motor rotates the gear train712and the override knob738to the auto position shutting off fluid flow at act908. In an automatic selection, the sensor108initiates a fluid flow when a user is detected in a field of view at act906. When an activation signal is received, an electronic switch electrically connected to the sensor108actuates the motor604at act910. Once the user is no longer detected, the motor rotates the gear train712, cam606, and the cam follower608from an active state of continuous fluid flow to an inactive state of no fluid flow at acts912and914. When in an automatic state, fluid will again flow when a user is again detected in the field of view.

The above described system and method provide an easy-to-install, reliable means of flushing a hands-free fixture without requiring continuous sensor detection. While the system and method have been described in cam and gear embodiments, many other alternatives are possible. Such alternatives include automatic actuators, solenoid driven systems, and any other system that uses valves for fluid distribution.

Furthermore, the detent is not limited to override control disclosed. The detent can be an electronic detent, comprising a programmable timing device that sustains an uninterrupted fluid flow for an extended period of time. Moreover, the system can also embrace other mechanical detents, for example, that lock movement of the motor604or the gear train712and/or the shaft732. One such embodiment can comprise a catch lever that seats within a channel of the spur gear728of the gear train712. Preferably, the torque of the motor604and/or a manual pressure can unlock some of these embodiments.

Many other alternative embodiments are also possible. For example, the mixing valve shown inFIGS. 4–6can comprise an above surface or an above-deck element that provides easily accessible hot and cold adjustments which allows users to adjust or preset the temperature of the water being dispensed from the spout. In an alternative embodiment, the hand-free fixture can include a scalding prevention device, such as a thermostatic control that limits water temperature and/or a pressure balancing system that maintains constant water temperature no matter what other water loads are in use. Preferably, the non-scalding device and pressure balancing systems are interfaced to and control the mixing valve602and are unaffected by water pressure variations.

In yet another alternative embodiment, the limits of travel of the pilot614can be defined by the contacts between the override arm724and the convex surfaces of the strike plate730. At one end of this embodiment, the override arm724strikes a positive moderate sloping side surface734of the strike plate730and at another end the override arm724strikes a substantially linear side surface736. In another alternative, pilot614movement causes the pilot supply air804shown infigure 8to be vented to the atmosphere which unseats the diaphragm610allowing fluid to flow from the inlet to the outlet port618and620. In this embodiment, the fluid which comprises a substance that moves freely but has a tendency to assume the shape of its container will flow continuously until the venting is closed. Once the vent is closed, a backpressure builds up on the diaphragm610closing the outlet port620.

Installation of the hands-free embodiments can be done above or below a sink deck or surface. While the complexity of the installation can vary, the above-described embodiments can use few pre-assembled parts to connect the outlet port620to an output accessory. For example, a valve pin seated within a keyway can provide a seal between the valve housing and the output accessory. An O-ring can also be used to provide a positive fluid tight seal between the valve housing and accessory.

While some presently preferred embodiments of the invention have been described, it should be apparent that many more embodiments and implementations are possible and are within the scope of this invention. It is intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.