An electrically controlled cold and hot water mixer faucet

Abstract: The invention relates to an electrically controlled mixer faucet for cold and hot water, in which the control member determining the mixing ratio is moved by an electric motor (7). The purpose is to achieve temperature control which is for the user more convenient than earlier, and an initial temperature which is independent of the previous user. The control of the motor (7) is dependent on a target detected between a source of light (19) and a photocell (20) by the photocell (20). If the photocell (20) does not detect a user, the motor control circuit (13) receives its reference value from a circuit (18) the signal given by which has been set in advance. It is possible to produce by means of a suitable delay circuit (22) a certain delay before this signal is switched on. If there is a user in the detection field of the photocell (20), the control circuit (13) re­ ceives its control signal via the press-buttons (14, 15) used by the user and via corresponding circuit means (16, 17) which form control signals. The control circuit (13) receives a signal corresponding to the actual value of temperature via a temperature sensor (23) installed in the water mixing space.

Description: The present invention relates to an electrically controlled cold and hot water mixer faucet according to the preamble of claim 1. Such a mixer faucet is known from DE-B2-2 323 841. There are previously known electrically controlled faucets of this type, which may have either separate motors for the control valves for cold and for hot water, or one motor moving the control member. In the prior-art faucets, the motor or motors adjusting the mixing ratio are usually controlled in such a way that they move the control member into a position which is determined by the temperature selected, by means of the control knob, by the user at any given time. Although it is, of course, possible to equip a faucet, in a manner known per se , with a stop knob protecting from high temperatures, it is possible that the temperature selected by the previous user does not please the next user. DE-B2-23 23 841 discloses an electrically- operated cold and hot water mixer wherein only one motor and one control circuit for the motor is required, the driving shaft of the motor being connected to both the cold water valve and the hot water valve, so as to drive those valves always in opposite directions. After use, the mixer will remain in the position used. The object of the present invention is therefore to provide an electrically controlled faucet in which the initial temperature is always independent of the previous user and the water temperature can, when necessary, be adjusted by the user upward or downward from the set initial value. Furthermore, the faucet is made such that the said initial temperature always sets automatically after use. This object is achieved by an electrically controlled cold and hot water mixer faucet, in which the control member determining the mixing ratio is moved by an electric motor controlled over a motor control circuit, characterized in that the control of the motor is arranged to depend on the output signal of a photocell or the like, said output signal of the photocell controlling a switch via which alternatively an electric reference quantity, capable of being set, or an electric quantity adjusted manually by the user is fed to the motor control circuit, in such a manner that, when the photocell does not detect any movement or target in its detection field, the motor receives said electric reference quantity and adjusts into a position corresponding to a preselected temperature of the mixed flow, and if the photocell detects a user the motor receives said electric quantity adjusted manually by the user. Preferably the arrangement is such that the adjusting of the motor into the said position takes place only with a period of delay after the previous user has left the detection field of the photocell. The invention and its other features and advantages are described below in greater detail in the form of an example and with reference to the accompanying drawings, in which Figure 1 depicts, partly as a cutaway, a thermostat faucet according to the invention, and Figure 2 is a diagrammatic representation of the control circuitry of the control motor. In Figure 1, reference numeral 1 indicates the faucet body, which in this case is substantially cylindrical. Inside the body there is installed a ratio valve 2, which controls the temperature of mixed water, its axial position determining the ratio between the inlet openings for cold water and hot water. Reference numeral 3 indicates the pressostat part, known per se , moving inside the ratio valve 2; the pressostat part rapidly levels out any changes of pressure. Reference numerals 4 and 5 indicate respectively the inlet pipes for cold and hot water, and numeral 6 indicates the outlet pipe for mixed water. The operation of a thermostat faucet such as this is quite well known previously and is not described here in greater detail. The axial movement of the ratio valve 2 is controlled by means of an electric motor 7, as follows. The output shaft 8 of the electric motor 7 works through a thread fit in conjunction with the sleeve 9 surrounding it. The sleeve 9 is controlled in the faucet body by means of a slip fit in such a manner that the sleeve cannot rotate. Thus the rotation of the shaft 8 produces an axial movement of the sleeve 9. To the sleeve 9 there is correspondingly attached a cup-like part 10, which acts on a spindle 11, attached to the ratio valve 2. Thus the motor 7 can push the ratio valve to the left in the figure, whereas the movement of the ratio valve to the right is produced by a spring 12, which keeps the spindle 11 tight against the part 10. The motor 7 is controlled by a temperature sensor in the water-mixing space, as will be described below with reference to Figure 2. Figure 2 thus depicts a block diagram of the electronics controlling the motor 7, the electronics being capable of being installed in the same casing as the motor. The actual control circuit of the motor is indicated by reference numeral 13. The control circuit is affected as follows: The user can, by pressing a button 14 or 15, raise or respectively lower the reference value fed to the control circuit 13. The circuits forming the reference value are indicated by reference numerals 16 and 17. The circuits 16 and 17 may be, for example, circuits which integrate the voltage value, in which case the circuit 16 linearly raises and the circuit 17 respectively linearly lowers the voltage value while the button 14, or respectively 15, is being pressed. The reference value mentioned above is fed to the circuit 13 when the switch S is in the position shown in the figure. If the switch S is in the other position, indicated by a dashed line, the value fed to the control circuit 13 is the preselected reference value obtained from the circuit 18, for example, corresponding to a temperature of 38 °C. The operation of the switch S is controlled as follows. In the area of the user there are installed an infrared source 19 and an infrared photocell 20 in such a manner that the photocell 20 detects whether there is a user blocking the ray of light. Thus the circuit 21 gives a binary, i.e. yes/no type, signal. If the photocell 20 does not detect a user, the circuit 21 draws the switch S into the upper position, and the selected reference value from the circuit 18 passes to the control circuit 13. At a point after the circuit 21 there is preferably installed a delay means 22, which delays the operation of the switch S for a selected time t, which may be, for example 25 s. This time is preferably also capable of being adjusted. Reference numeral 23 indicates the above-mentioned temperature sensor installed in the water-mixing space, the control circuit 23 rotating the motor 7 until the temperature sensed by the temperature sensor 23 corresponds to the reference value received via the switch S of the control circuit 13.

Claims: An electrically controlled cold and hot water mixer faucet, in which the control member (2) determining the mixing ratio is moved by an electric motor (7) controlled over a motor control circuit (13), characterized in that the control of the motor (7) is arranged to depend on the output signal of a photocell (20) or the like, said output signal of the photocell (20) controlling a switch (S) via which alternatively an electric reference quantity, capable of being set, or an electric quantity adjusted manually by the user is fed to the motor control circuit (13), in such a manner that, when the photocell (20) does not detect any movement or target in its detection field, the motor (7) receives said electric reference quantity and adjusts into a position corresponding to a preselected temperature of the mixed flow, and if the photocell (20) detects a user the motor (7) receives said electric quantity adjusted manually by the user. A mixer faucet according to Claim 1, characterized in that between the photocell (20) and the control circuit (13) of the motor (7) there is installed a delay means (22) in such a manner that the adjusting of the motor into the preselected position takes place with a certain delay after the detection of no movement or target by the photocell (20). A mixer faucet according to Claim 1, characterized in that the electric quantities are voltages. A mixer faucet according to any of the above claims, characterized in that, for the purpose of adjustment by the user, in faucet is equipped with press-buttons (14, 15) by means of which the temperature is adjusted in either direction from the selected initial temperature. A mixer faucet according to any of the above claims, characterized in that the preselected initial temperature is approximately 38°C.

Inventors: MAEAETTAENEN ARI ESA JUHANI, NILSSON PEKKA WALDEMAR, MAEAETTAENEN, ARI ESA JUHANI, NILSSON, PEKKA WALDEMAR, Määttänen, Ari Esa Juhani
Applicants: ORAS OY
Application year: 1989
Main classification: F16K31
IPC codes: E03C1, G05D23