Technical Field

This invention relates to a self-closing mechanical faucet with an ergonomically convenient and manually adjustable flow-control for intermittent outflow use to reduce fluid wastage.

Background Art

Faucets at the sinks in public washrooms are often fitted with special valves or devices that prevents wastage of water by people forgetting to turn off the water tap after use or by using an unnecessarily large amount of water. Most mechanical faucets of these types usually operates using intermittent flows that restricts the user to a fixed amount of water each time the faucet valve-control knob or stem is manually pushed and released, therefore the user has hardly any control of the outflow rate. If more water is required to continue washing, one hand must be used to repeatedly press and release the faucet control that is usually placed above the water outlet spout. Other water-saving faucet designs have the valve-control manual contact tip too close directly below the faucet spout orifice to be continuously pressed or pulled while washing both hands at the same time. There are faucets with electronic proximity sensor to detect the presence of the user's hands and automatically open the faucet valve only when it is being used but these sophisticated electronically controlled faucets are rather expensive and not often used. Disclosure of Invention

The present invention aims to provide a useful alternative to known self-closing mechanical faucets for washing using intermittent outflow to reduce fluid waste. This is achieved by placing the faucet valve-control which must be pressed or pushed for fluid outflow near enough to the faucet outlet spout but not in the path of the outflowing fluid so the valve-control that is user-adjustable for variable outflow rate can be conveniently reached by the person's hand, wrist or forearm while the hands are being washed in the fluid flowing out of the faucet spout. It is better that the manual pressing by the user on the faucet valve-control is a pushing action because the person is usually facing over the faucet, therefore it is ergonomically more effortless for the user's hand to push on the faucet control, and not by pulling since it is easier to quickly release the control with a smooth direct hand movement towards the body. The ergonomic position of the lever handle or knob of the faucet valve-control is located in a region of space (FIG. 1) beside the path of the outflowing fluid from the faucet spout 1 termed as Control Region 5. The position of this valve-control lever is inclined towards the user so that it can be easily pressed or pushed by the hands, wrist or forearm that may be being washed under the faucet outlet 1, so the distance of the perimeter radius D of this region from the outlet of the faucet spout is about the width of a human hand span that is approximately 15-25 centimeter, and both the double-arrow in FIG. 1 is pointing towards the user. Since the same washing hand is conveniently interacting with the faucet valve the user is able to actively adjust the outflow rate according to his requirement thereby attaining ergonomic feedback control of the fluid outflow. The manual release of this faucet valve-control after usage will immediately or slightly later stop the outflow of fluid hence reducing unnecessary fluid loss. An option, is to interrupt this self-closing function with a releasable restrain to be latched if required by the user, although this will interfere with its fluid-saving feature. EXAMPLE

In order that the invention may be more readily understood and put to practical effect, an example of the invention will now be described with reference to the accompanying drawings. This example is made from a faucet valve that will fully open through a turn of the faucet valve-control by rotating it 90° from the close position. This type of ceramic valve 7 (FIG. 6) is available from plumbing suppliers nowadays. In order to make the faucet close by itself when manually released, a torsion coil spring 8 is attached to the rotatable valve stem-rod 9 and valve body so that there is a torque on the valve stem 9 and control lever handle towards the close direction. It is preferable that this counteracting torsion spring does not rust. This torsion spring-closed valve 10 is placed inside the faucet valve rotatable housing 3 (FIG. 2) with a straight well-rounded smooth surface valve-control lever handle, and its lever contact tip 2 in the Control Region space 5 (FIG. 1) towards the user so the lever can be conveniently pushed on by the user's hand while it is being washed as explained above. The axis of rotation of the faucet lever may be angled pointing 5° - 80° (FIG. 3) to the right from the direction towards the user. Additionally this axis may also be slightly tilted away from the horizontal. The normally closed position of the lever may incline 0° - 70° from vertical (FIG. 4) depending on the mains pipe water pressure so that the contact tip of the lever handle 2 when normally closed is at a position about towards the user. This valve-control lever close-position will make it more ergonomically easier to turn on the faucet (anti-clockwise in this example) by pushing any part of the valve-control lever stem with a downwardly inclined forward direction because most people are right-handed, and manual release of the lever is also easier from this inclined position. If the water pressure in the pipe is high causing an overly large outflow at the slightest turn of the control lever, a preset excess rotational free-play is allowed between the lever handle and the faucet valve so that the lever can slightly rotate in either direction without affecting the outflow rate and hence reduces the valve-control sensitivity. When the user pushes the faucet lever handle stem it will rotate downwards anticlockwise and is adjusted such that the desired flow rate is achieved when the tip of the lever 2 is at a position slightly lower than the level of the faucet outlet spout that is in the Control Region 5. The valve-control lever will usually need to rotate through an angle that is less than the 90 degrees angle limit for the fully open position especially when the water pressure in the pipe 4 is high, therefore it is possible to rotate the control lever even further for greater outflow rate if desired. Since the hand that presses the valve-control lever will usually move about while it is being washed, there is a tendency to unintentionally push the lever further causing to splash too much water due to excessively high outflow rate. In order to prevent such accidental over-rotation of the valve-control lever, when at the open- position where the lever angle at the desired optimum flow rate is attained, the valve-control may be mechanically stopped to prevent further rotation or another stronger counteracting spring which requires a larger torsion force is contacted to stiffen any further lever rotation so that it is manually much more difficult to increase the outflow rate and thus tends to hinder accidental over-rotation.

The above example is only one of the many ways this self-closing faucet for adjustable intermittent outflow may be designed with ergonomic feedback control using conventional faucet parts. Another variant of the above design allows some water to be diverted to the control lever handle so that the lever tip is momentarily rinsed for better sanitation. The faucet body shape design, position of inlet pipe and handle lever shape design may of course be varied, such as adding a roller contact tip 6 (FIG. 5) on the handle lever to reduce rubbing friction in order to facilitate hand movement. Although this example ergonomic self-closing faucet was intended for intermittent'flow, if required it can be used for continuous outflow operation by adding an optional manually releasable restrain that may be latched to hold the valve continuously in any open-position or further delay the stop of fluid outflow longer, but this will affect its water-saving feature. Brief Description of Drawings

FIG. 1 shows the region of space defined as Control Region 5 where the ergonomic valve-control lever handle contact tip must be located to conveniently turn on and adjust the self- closing intermittent flow faucet. The top plane boundary surface of this Control Region space 5 is at about the faucet spout opening level perpendicular to the spout outflow direction and also extends behind the faucet outlet spout 1. The dash lines shows the path of the outflowing fluid from the faucet outlet spout.

FIG. 2 is front view of the example user adjustable torsion spring-closed faucet that is pressed or pushed by the user in the open-position with fluid flowing out of the spout at optimum outflow rate. Like normal faucets, the spring-closed ceramic faucet valve 10 (FIG. 6) is inside the control lever rotatable housing 3. The cylindrical valve-control lever tip 2 is in the Control Region space 5 of FIG. 1.

FIG. 3 is top view of the example faucet at the same user-pushed open-position as in FIG. 2 showing the inlet water pipe 4. The valve-control lever rotational axis is about 45 degrees to the right. The double arrows in any of the diagrams points towards the body of the user.

FIG. 4 is the same faucet as above that has been manually released and its similar shaped lever handle is at the fully spring-closed position viewed from the right.

FIG. 5 is a perspective drawing of the faucet viewed slightly from below with the handle lever in the same normally closed position as in FIG. 4, showing the spout 1 opening and with a cylindrical roller-handle 6 that can rotate loosely both directions.

Fig. 6 shows how a conventional normally available ceramic faucet valve 7 is modified into the spring-closed valve 10 by attaching a torsion helical spring 8.