Water-closet bowl automatic flushing system

Abstract: A stool automatic-flushing system which detects the state where an evacuator sits on a stool (1) for evacuation and, instead of operating a flush handle for flushing after the end of the evacuation, performs flushing in association with the evacuator's action of standing up to leave the stool (1), and which also is provided with a forced flushing sensor (5,6) so that water can be flowed for flushing halfway with intention of the user.

Description: The present invention relates to a water-closet bowl automatic-flushing system which detects the state where a user sits on a closet seat for defecation and operates in association with the user standing up to leave. Furthermore a forced flushing sensor is provided in order to flow water under intention of the user. Automatic flushing systems are known from the prior art. AU-B-590,492 describes a flushing system comprising sensor means to detect the presence of a user. However, only the use of this systems for a urinal is described. US-A-4 570 272 discloses a toilet bowl flushing device which comprises means of detecting approach and departure of users of the bowl. The operation of the system follows a specific timing chart. Means allowing the user or someone cleaning the toilet to actuate or stop the flushing device are not described. A water-closet bowl automatic-flushing system of the present invention disposes a defecating position detection sensor at the rear of the toilet so as to project light to the back of the user. The water-closet bowl automatic-flushing system of the present invention is so constructed that, when the user sits on the closet seat prior to defecation, preliminary flushing is carried out and the interior of the closet bowl is wetted with water so as to make it easy to wash out faeces by full water flush. The preliminary water-flushing mechanism comprises a photosensor controllable in non-contact without operating a lever or a handle. Fig. 1 is a perspective view of a toilet with a water-closet bowl automatic-flushing system, Fig. 2 is a side view showing that a first position M1 where a user sits on the closet seat for defecation and a second position M2 where he leaves after the end of evacuation are detected by an evacuating position detection sensor, Fig. 3 is a plan view of a closet provided with the stool automatic-flushing system, Fig. 4 is a side view of the closet of Fig. 3, Fig. 5 is a plan view of the defecating position detection sensor and a forced flushing sensor, Fig. 6 is a control block diagram of the bowl automatic-flushing system of the present invention, and Fig. 7 is a time chart of the diagram of Fig. 6. In the following the invention is explained in more detail by way of an example. In a toilet room is disposed a pipe-line covering stand 13, in which water-flushing pipes 16 are housed. A bowl 1 is disposed at the center of the toilet room and a closet seat 2 is mounted on the bowl 1, the closet seat 2 being upwardly rotatable for use by men for urination. At the center of a decorative cover 7 is disposed a sensor cover 8 and an electronic box 15 is attached to the rear surface of the decorative cover 7. On the upper surface of the electronic box 15, as shown in Fig. 5, is provided a sensor mounting plate 9, to which a forced water-flushing sensor and a defecating position detection sensor or, for example, an optical system are fixed. At the upper portion of the sensor mounting plate 9 are disposed side by side a forced water-flush sensor projector 5 and a forced water-flush sensor photodetector 6 constituting the forced water-flush sensor. Also, at the lower portion of the same is disposed a defecating position detection sensor photodetector 3 and at the lowermost portion of the same is disposed a defecating position detection sensor projector 4. Between the evacuation position detection sensor photodetector 3 and the defecating position detection sensor projector 4 are disposed a human body detection display lamp 14, a remote control photodetector 10, and a remote control stop display lamp 11. At the remote control photodetector 10, as shown in Fig. 5, there is separately provided a remote control operation device which serves to stop the bowl automatic-flushing system in order not to flow water in vain each time a cleaner approaches the bowl 1 for cleaning the toilet room. When the infrared ray is emitted from the remote control operation device and received by the remote control photodetector 10, a circuit of the bowl automatic-flushing system is off so that the remote control stop display lamp 11 is adapted to display that the bowl automatic-flushing system stops. After the end of cleaning, when the infrared ray is again emitted by the remote control operation device, the bowl automatic-flushing system is reset and the remote control display lamp 11 is switched off, thereby starting the automatic-flushing system. When the infrared ray is projected from the forced flushing sensor projector 5 and reflected by the hand of the user, the forced flushing sensor photodetector 6 detects the infrared ray to flush the bowl with water. The forced flushing sensor projector 5 and the forced flushing sensor photodetector 6 constituting the forced flushing sensor, as shown in Fig. 5, are made small in sensor length c thereof, as shown in Fig. 2, and there is an elongate slot open at the center of the closet seat 2, so that, when a male opens the closet seat 2 to urinate, the forced flushing sensor does not operate. The male, after the end of urination, enters his hands into the length c of forced flushing sensor to intercept the infrared ray so as to thereby flow water. The sensor length of the infrared ray from the defecating position detection sensor, as shown in Fig. 2, is adapted to be switched into either a defecation state sensor length b or an end state sensor length a. When the toilet room is empty, in other words, at the time when the former user gets out therefrom, the defecating position detection sensor has been switched to be of the defecation state sensor length b. In the state where the user enters into the toilet room and sits on the closet seat 2, a person is within the defecation state sensor length b, whereby the bowl automatic-flushing system starts its operation. Simultaneously with the above, the defecating position detection sensor is switched to the end state sensor length a, and then decides whether or not the user gets out from the end state sensor length a, thereby turning on the defecation finish switch. The defecating position detection sensor is switched into the end state sensor length a and defecation state sensor length b by changing a response difference of the infrared ray sensor, but two separate infrared ray sensors are not provided. Next, explanation will be given on operation of the present invention in accordance with Figs. 6 and 7. Fig. 6 is a block diagram for control of the bowl automatic-flushing system of the present invention and Fig. 7 is a time chart thereof. At first, a user enters into the toilet room, at which time the defecating position detection sensor has been switched to be of the defecation state sensor length b, the length b being about 450 mm, so that in the state where he enters into a first position M1 and sits on the closet seat 2, the defecating position detection sensor detects the above so as to turn on the defecation switch, and when the time of turning on the defecating switch due to the defecation state sensor length b continues for about three seconds, the preliminary flushing timer is on, thereby preliminarily flowing water for flushing the bowl 1. When the user enters into the defecation state sensor length b and the defecation switch is on, the defecating position detection sensor has been switched to the end state sensor length a. Next, when the user finishes the defecation and stands up so as to get out from the second position M2 outside a range of end state sensor length a of about 950 mm, the defecating position sensor turns on the defecation end switch, so that, when the state where the defecation switch is on continues for about t2 seconds (about five seconds), the full flushing timer is turned on. Then, more water than during the preliminary flushing is flowed to perform the full flushing. Also, a forced flushing sensor separate from the defecating position sensor is provided, so that the user intercepts the infrared ray by his hands and the forced flushing sensor is turned on to perform the forced flushing. Separately, an equipment protective timer is provided. When the full flushing is not carried out for 24 hours or more, flushing is arranged to be carried out once every 24 hours in order to protect the bowl automatic-flushing system. The equipment protective timer starts the time counting from the time point of finishing the full flushing so that, when the remote control operation device 20 turns on the flushing switch, the time counting is intermitted. When a cleaner operates the remote control operation device 20 to turn on a cleaning switch and to turn off the same after the end of flushing, the full flushing timer is on so as to perform full flushing. The present invention has the following effect. The first position M1 where the evacuation switch is on is shifted from the second position M2 where the defecation finish switch is on, so as to give hysteresis, whereby unstable control generated when both the positions are coincident with each other can be eliminated. As claimed in Claim 3, the forced flushing sensor is provided which operates by intercepting the infrared ray by the user's hands. When the user intends to carry out particular flushing, he can carry out water flushing at any time. The forced flushing sensor is part of the decorative cover 7 at the rear of the toilet and disposed in proximity to the defecating position detection sensor, whereby parts with reference to the electronic circuit can integrally be disposed.

Claims: Automatic toilet bowl flushing system, comprising a defecating position sensor (3,4) disposed at the rear of the closet (1), said sensor providing a signal for a preliminary flushing when a user sits in a first position (M1) and a signal for full flushing when the user after defecation reaches a second position (M2), characterized in that the sensor range of the defecating position detection sensor is switched from a sensor range b to a longer sensor range a when the user sits in said first position (M1) and is switched again to a shorter sensor range b when the user reaches said second position (M2). Automatic toilet bowl flushing system according to Claim 1, characterized in that said sensor range b is about 450 mm and said sensor length a is about 950 mm. Automatic toilet bowl flushing system according to Claim 1 or 2, characterized in that additionally a forced flushing sensor (5,6) which can be operated under intention of the user is provided in proximity of said defecating position detection sensor (3,4). Automatic toilet bowl flushing system according to any of the preceding Claims, characterized in that it additionally comprises a remote control photodetector (10) to switch off the system.

Inventors: SAKAKIBARA SHIGERU, TAKAGI SHIGERU, SAKAKIBARA, SHIGERU, TAKAGI, SHIGERU
Applicants: INAX CORP, INAX CORPORATION
Application year: 1991
Main classification: E03D5
IPC codes: E03D5