Patent Publication Number: US-7900290-B2

Title: Dual flush refill device

Description:
RELATED APPLICATIONS 
     This application relates to, claims priority from, and incorporates herein by reference, as if fully set forth, U.S. Provisional Patent Application Ser. No. 60/652,102 filed on Feb. 10, 2005 and entitled “DUAL REFILL DEVICE”. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to dual flush systems for toilets and particularly to a refill device for dual flush systems. 
     2. Description of Prior Art and Related Information 
     Demand for dual flush toilets continues to grow as a result of concerns over water shortage. Such toilets conserve water by providing the user with options for a partial flush and full flush for liquid and solid wastes, respectively. Dual flush toilets typically deliver lesser or greater amounts of refill water to the bowl as a result of a partial or full flush, respectively, by varying the time during which refill water is directed to the bowl. Thus, less time is provided for flowing refill water to the bowl during a partial flush while more time is provided for a full flush. 
     In many European countries, a “wash-down” toilet bowl  2  as shown in  FIG. 1  is typically employed whereby the force of the water head during a flush pushes the contents in the bowl  2  through a relatively large drain pipe. In such wash-down toilets, only a relatively minor amount of fluid is required to reside in the bowl  2  in a default, rest state so as to block sewage gas from the drain pipe  4  from entering through the bowl into the surrounding atmosphere. 
     In several non-European countries, such as the U.S., a siphonic toilet is employed.  FIG. 2  is a cutaway side view of a typical siphonic toilet  5  as used in the U.S. An inverted U-shaped flow path  7  is disposed between a toilet bowl  9  and an outlet  12 , such as a drain pipe. Siphonic toilets  5  require sufficient water in the bowl  9  to fill the inverted flow path so as to induce siphonic action that drains waste in the bowl  9  during a flush cycle. As shown in  FIG. 3 , siphonic toilets  5  typically leave a very small amount of water  14  in the bowl  9  after a flush cycle. This residual water  14  is insufficient for blocking sewage gas from the outlet  12  and for preparing the bowl  9  for the next flush. Accordingly, the bowls  9  in siphonic toilets  5  need to be refilled with fresh water to a certain level in order to function properly. 
     The problem with incorporating a dual flush system into a siphonic toilet lies in refilling the bowl to a proper level without wasting water. In a dual flush system, the amount of time provided for refilling the bowl varies with each type of flush. In particular, more time is provided for refilling during a full flush, and less time for a partial flush. Accordingly, if the same volume of refill water is supplied for both types of flushes, then problems arise with either oversupply or undersupply of water due to the differing refill times for partial and full flushes. For example, oversupply occurs when a toilet is set to provide a high flow rate of refill water for a partial flush. Though adequate for the partial flush which has a shorter duration of time for refill, excessive refill water is directed into the bowl and thus wasted during the longer, full flush. Conversely, if a lower flow rate of refill water is delivered for each type of flush, then the bowl will be adequately filled during the longer, full flush. During the partial flush, however, the bowl will be inadequately filled due to the shorter refill time. 
     Thus, the varying durations of time for refilling the bowl in a dual flush siphonic toilet leads to either water waste or insufficient refilling of the bowl. 
     SUMMARY OF THE INVENTION 
     The present invention provides structures and methods which overcome the deficiencies in the prior art. 
     In particular, structures and methods are provided for varying the refill flow rate, or simply refill rate, for dual flush siphonic toilets. Thus, depending upon the type of flush chosen, the refill rate is controlled to deliver a sufficient amount of refill water to the bowl without oversupplying, or wasting, refill water. 
     In one aspect, a dual flush refill device is provided for use in connection with a toilet having a toilet bowl, a refill tube, an overflow tube, a partial flush button and a full flush button. The device comprises a slide including a first hole and a second hole. The first hole defines a first area and the second hole defines a second area that is smaller than the first area. At least one actuator causes the first hole to be in fluid communication with the refill tube and the overflow tube when the partial flush button is engaged, and causes the second hole to be in fluid communication with the refill tube and the overflow tube when the full flush button is engaged. 
     The actuator preferably comprises a first cam coupled to the partial flush button and configured to move the slide a first distance to align the first hole with the refill tube, and a second cam coupled to the full flush button and configured to move the slide a second distance to align the second hole with the refill tube. The device further comprises a button bracket and a refill tube connector coupled to the button bracket and the refill tube. The actuator aligns the first hole with the refill tube connector when the partial flush button is engaged, and aligns the second hole with the refill tube connector when the full flush button is engaged. 
     In another aspect, a dual flush refill device may comprises a variety of different means for varying the flow rate between the refill tube and the overflow tube in response to either a full flush or partial flush selection by the user. The device is adapted for use in connection with a toilet having a toilet bowl, a refill tube, and an overflow tube, a partial flush button and a full flush button. The device comprises means for providing a first flow rate between the refill tube to the overflow tube in response to the partial flush button being engaged, and means for providing a second flow rate between the refill tube to the overflow tube in response to the full flush button being engaged, with the second flow rate being lesser than the first flow rate. 
     The device further comprises at least one actuator that activates either the means for providing the first flow rate or the means for providing the second flow rate. The means for providing the first flow rate comprises a first passageway while the means for providing the second flow rate comprises a second passageway. The actuator causes the first passage to be in fluid communication with the refill tube and the overflow tube when the partial flush button is engaged, and causes the second passage to be in fluid communication with the refill tube and the overflow tube when the full flush button is engaged. 
     The actuator preferably comprises a first cam coupled to the partial flush button and configured to move the slide a first distance to align the first passageway with the refill tube, and a second cam coupled to the full flush button and configured to move the slide a second distance to align the second passageway with the refill tube. The device further comprises a button bracket and a refill tube connector coupled to the button bracket and the refill tube. The actuator aligns the first passageway with the refill tube connector when the partial flush button is engaged, and aligns the second passageway with the refill tube connector when the full flush button is engaged. 
     The means for providing the first flow rate may also comprise a hole having a full size while the means for providing the second flow rate comprises a slide to partially block the hole. 
     Alternatively, the means for providing the first flow rate may comprise a large section of a hole defined in a slide while the means for providing the second flow rate comprises a small section of the hole. 
     A method for refilling a bowl of a dual flush toilet is also provided. The method comprises providing a first flow rate of water from a refill tube to an overflow tube for a first duration of time in response to a partial flush, providing a second flow rate of water from the refill tube to the overflow tube for a second duration of time in response to a full flush, the second flow of water being lesser than the first flow of water, the second duration of time being longer than the first duration of time, and filling the toilet bowl with an equal volume of water from the overflow tube in response to either the partial flush or the full flush. 
     The step of providing the first flow rate of water from the refill tube to the overflow tube for the first duration of time in response to the partial flush comprises aligning a first hole with a refill tube connector, with the first hole defining a first area. The step of providing the second flow rate of water from the refill tube to the overflow tube for the second duration of time in response to the full flush comprises aligning a second hole with the refill tube connector, with the second hole defining a second area smaller than the first area. 
     The step of aligning the first hole with the refill tube connector may comprise moving the first hole with a first cam, and the step of aligning the second hole with a refill tube connector comprises moving the second hole with a second cam. 
     The step of providing the first flow rate of water from the refill tube to the overflow tube for the first duration of time in response to the partial flush may comprise providing fluid communication between the refill tube and the overflow tube with a first passageway. The step of providing the second flow rate of water the refill tube to the overflow tube to the bowl for the second duration of time in response to the full flush may comprise providing fluid communication between the refill tube and the overflow tube with a second passageway. The step of providing fluid communication between the refill tube and the overflow tube with a first passageway comprises positioning the first passageway between the refill tube and the overflow tube while the step of providing fluid communication between the refill tube and the overflow tube with a second passageway comprises positioning the second passageway between the refill tube and the overflow tube. 
     Alternatively, the step of providing the first flow rate of water from the refill tube to the overflow tube for the first duration of time in response to the partial flush may comprise exposing a hole in fluid communication with the refill tube, while the step of providing the second flow rate of water the refill tube to the overflow tube to the bowl for the second duration of time in response to the full flush comprises partially blocking the hole. 
     As a further alternative, the step of providing the first flow rate of water from the refill tube to the overflow tube for the first duration of time in response to the partial flush comprises moving a large section of a hole defined in a slide into fluid communication with the refill tube, while the step of providing the second flow rate of water the refill tube to the overflow tube to the bowl for the second duration of time in response to the full flush comprises moving a small section of a hole defined in a slide into fluid communication with the refill tube. 
     In summary, a dual flush refill device refills a bowl of a siphonic toilet with adequate supply of refill water in response to either a full or partial flush without wasting the refill water. The device provides a relatively high flow rate of refill water from a refill tube to an overflow tube in response to a partial flush, and a relatively low rate of refill water from the refill tube to the overflow tube in response to a full flush. As a result, the toilet bowl is refilled with a substantially similar volume of refill water regardless of which flush option is selected. 
     The invention, now having been briefly summarized, may be better appreciated by the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is cutaway side view of a “wash-down” toilet in the prior art; 
         FIG. 2  is a cutaway side view of a siphonic toilet in the prior art showing a water level in a toilet bowl at a rest state; 
         FIG. 3  is a cutaway side view of a siphonic toilet in the prior art showing an insufficient water level in the toilet bowl at a rest state; 
         FIG. 4  is a perspective view of a preferred embodiment of a dual flush refill device; 
         FIG. 5  is a perspective view of a preferred embodiment of the dual flush refill device in a partial flush state; 
         FIG. 6  is a perspective view of a preferred embodiment of the dual flush refill device in a full flush state; 
         FIG. 7  is a perspective view of a second preferred embodiment of the dual flush refill device in a partial flush state; 
         FIG. 8  is a perspective view of the second preferred embodiment of the dual flush refill device in a full flush state; 
         FIG. 9  is a perspective view of a third preferred embodiment of the dual flush refill device in a partial flush state; 
         FIG. 10  is a perspective view of the third preferred embodiment of the dual flush refill device in a full flush state; 
         FIG. 11  is a perspective view of a fourth preferred embodiment of the dual flush refill device in a partial flush state; 
         FIG. 12  is a perspective view of the fourth preferred embodiment of the dual flush refill device in a full flush state; and 
         FIG. 13  is a diagram of a preferred method of refilling a bowl of a dual flush toilet. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention and its various embodiments can now be better understood by turning to the following detailed description wherein illustrated embodiments are described. It is to be expressly understood that the illustrated embodiments are set forth as examples and not by way of limitations on the invention as ultimately defined in the claims. 
     In  FIG. 4 , a preferred embodiment of a dual flush refill device is illustrated and designated generally by the reference numeral  20 . The device  20  is particularly configured for use in connection with siphonic toilets which induce siphonic action to drain waste in the toilet bowl. As described more fully below, the device  20  controls the refill flow rate, or simply refill rate, by providing a high flow rate of refill water in response to a partial flush and a low flow rate of refill water in response to a full flush. 
     The device  20  comprises a first, full-flush refill mechanism  22  and a second, partial-flush refill button mechanism  24 . By varying the flow rate between the two refill mechanisms  22 ,  24 , the device  20  thus refills the toilet bowl of a siphonic toilet to an adequate level for a partial flush and a full flush without oversupplying refill water. 
     The full-flush refill mechanism  22  comprises a first, full-flush button  26  coupled to a first push rod  28 . A first cam  31  is coupled to the first push rod  28 . The partial-flush mechanism  24  comprises a second, partial-flush button  33  coupled to a second push rod  35 . A second cam  37  is coupled to the second push rod  35 . 
     The device  20  comprises a slide  40  that defines two passageways  42 ,  44  for providing fluid communication between a refill tube  43  and an overflow tube  45 . In particular, a large passageway  42  comprises a relatively large hole  42  that defines a large area for enabling a relatively higher flow rate therethrough. A small passage  44  comprises a relatively small hole  44  defining a small area for enabling a relatively lower flow rate therethrough. A refill tube nipple, or connector,  46  is coupled to a button bracket  48  and adapted to be coupled to the refill tube  43 . The tube connector  46  is thus designed to remain stationary while the slide  40  is moved horizontally to align either of the two holes  42 ,  44  depending upon the type of flush engaged by the user. The slide  40  also defines a slot  50  for receiving the push rods  28 ,  35  and cams  31 ,  37 . The slot  50  comprises a generally large central section  52  and a pair of opposing sections  54 ,  56  designed for receiving and engaging the cams  31 ,  37 , respectively, as discussed in operation further below. 
       FIG. 5  illustrates the operation of the refill device  20  in a partial flush state, or position,  58  when the partial flush button  33  is engaged. When a partial flush option is selected by a user, a shorter amount of time is provided for refilling the toilet bowl (not shown). Accordingly, the device  20  refills the toilet bowl to an adequate level in such lesser duration of time by increasing the flow rate of water being delivered from the refill tube to the overflow tube leading to the toilet bowl. In particular, pressing the partial flush button  33  moves the partial flush push rod  35  downward, thereby causing the partial flush cam  37  to move through the slot  50 , specifically the partial flush section  56 . This causes the slide  40  to move horizontally in a first direction to the partial flush position  58  whereby the large hole  42  is aligned with the refill tube nipple  46 . Thus, the large hole  42  is brought into fluid communication with the refill tube  43 , thereby creating a large passageway  42  of fluid communication between the refill tube  43  and the overflow tube  45 . 
     As a result, a relatively high flow rate is provided for directing refill water from the refill tube  43  to the overflow tube  45  and ultimately to the toilet bowl. It will be appreciated that when the partial flush option is selected, which limits the duration of time by which the toilet bowl can be refilled, the device  20  adequately compensates for this reduced “refill time” by providing a higher flow rate for directing water from the refill tube to the toilet bowl. 
       FIG. 6  illustrates the operation of the refill device  20  in a full flush state, or position,  61  when the full flush button  26  is engaged. When a full flush option is selected by a user, a longer amount of time is provided for refilling the toilet bowl (not shown). Accordingly, the device  20  refills the toilet bowl to an adequate level in such greater duration of time without overflowing the bowl or using excessive refill water. This is accomplished by decreasing the flow rate of refill water being delivered from the refill tube to the overflow tube leading to the toilet bowl. In particular, pressing the full flush button  26  moves the full flush push rod  28  downward, thereby causing the full flush cam  31  to move through the slot  50 , specifically the full flush section  54 . This causes the slide  40  to move horizontally in a second, opposite direction to the full flush position  61  whereby the small hole  44  is aligned with the refill tube nipple  46 . Thus, the small hole  44  is brought into fluid communication with the refill tube  43 , thereby creating a small passageway  44  of fluid communication between the refill tube  43  and the overflow tube  45 . 
     As a result, a relatively low flow rate is provided for directing refill water from the refill tube to the overflow tube and ultimately to the toilet bowl. It will be appreciated that when the full flush option is selected which extends the duration of time by which the toilet bowl can be refilled, the device  20  adequately compensates for this extended “refill time” by providing a lesser flow rate for directing refill water from the refill tube to the toilet bowl, thereby conserving water while adequately refilling the bowl. Without such restriction in the refill flow rate during a full flush, excessive water will be directed into the bowl and out the drain outlet, thus wasting the clean refill water. 
     In the preferred embodiment, the slide  40  is thus horizontally movable between two discrete positions  58 ,  61  as shown in  FIGS. 5 and 6 , respectively, so as to provide fluid communication between the refill tube and the overflow tube at differing flow rates. Accordingly, each cam  31 ,  37  comprises an actuator  31 ,  37  for opening fluid communication between the refill tube and the overflow with differently sized passageways that define differing flow rates depending upon which of the two dual flush options is selected by the user. Therefore, whether a partial flush or full flush is selected by the user, the toilet bowl is refilled with the same volume of refill water each time. Furthermore, this equal volume of refill water being provided with each flush is sufficient for blocking fumes from the drain pipe and for inducing siphonic action in the bowl with the next anticipated flush. 
     It is to be expressly understood that a variety of different structural mechanisms may be employed to vary the flow rates between the refill tube and the overflow tube. The interaction between the cams  31 ,  37  and the slide  40  with holes  42 ,  44  comprise merely one preferred embodiment of alternating flow rates between the refill tube and the overflow tube. 
     This is shown in a second preferred embodiment illustrated in  FIGS. 7 and 8  where elements of similar structure are designated by the same reference numerals followed by the lower case “b”. Here, instead of providing two passageways or holes, a single hole or passageway  63  is defined in the slide  40 . In this preferred embodiment, the hole  63  is shaped as an elongate slot such that it can be fully open to the connector  46   b  in the partial flush state, as shown in  FIG. 7 , or partially open to the connector  46   b  in the full flush state. Thus, the single passageway  63  enables a high flow rate of refill water from the refill tube  43   b  when the passageway  63  is fully open to the connector  46   b , and a lower flow rate of water from the refill tube  43   b  when the passageway  63  is partially open to the connector  46   b . In the full flush state shown in  FIG. 8 , it will be appreciated that portions of the slide surrounding the slot  63  serve to block water flow from the refill tube  43   b.    
     It will be appreciated that a single passageway formed in a slide may take a number of different configurations to create entirely open fluid communication or partial fluid communication. As a further example,  FIGS. 9 and 10  illustrate a third preferred embodiment where elements of similar structure are designated by the same reference numerals followed by the lower case “c”. In  FIGS. 9 and 10 , a single hole or passageway  65  is formed in a slide  40   c  with a large section  67  configured for full fluid communication and a smaller section  69  for partial fluid communication. In the illustrated embodiment, the single passageway  65  comprises a key shape although it is to be expressly understood that the passageway  65  may take several different shapes to accomplish the same purpose of creating full and partial fluid communication.  FIG. 9  illustrates the slide  40   c  in the partial flush state with full fluid communication as the large section  67  of the passageway  65  is aligned with the connector  46   c .  FIG. 10  illustrates the slide  40   c  in the full flush state where the small section  69  of the passageway  65  is aligned with the connector  46   c  for providing a lower refill flow rate of water from the refill tube  43   c.    
       FIGS. 11 and 12  illustrate a fourth preferred embodiment where elements of similar structure are designated by the same reference numerals followed by the lower case “d”. The fourth preferred embodiment  20   d  comprises a slide  40   d  without any holes. Instead of restricting flow with large and small holes, or large and small sections of a single hole, the slide  40   d  is configured to move completely out of the fluid path between the connector  46   d  and the overflow tube  45   d  when the partial flush button  33   d  is engaged as shown in  FIG. 11 . Accordingly, the placement of the cams in this illustrated embodiment have been reversed with respect to earlier embodiments to accomplish the desired movement of the slide  40   d . In this partial flush state, the device  20   d  enables a high flow rate as refill water from the refill tube  43   d  flows unrestricted and unobstructed to the overflow tube  45   d . In particular, refill water flows from the refill tube  43   d  to the connector  46   d  through a hole  72  defined on the button bracket  48   d  that is entirely exposed. In particular, when a partial flush button  33   d  is engaged, a partial flush cam  37   d  moves a slide  40   d  to expose the entirety, or at least a majority portion, of the hole  72 . This provides a relatively high refill flow rate which is required for shorter duration of the partial flush. 
     In a full flush state as shown in  FIG. 12  when the full flush button  26   d  is pressed, the slide, or block,  40   d  is moved to partially block, or choke, the hole  72  so as to reduce the flow rate therethrough. This partially closed hole  72  provides a relatively low flow rate for the extended duration of the full flush. Thus, the device  20   d  serves as a valve that alternates the flow rate from the refill tube  43   d  to the overflow tube  45   d  by reducing the size of the hole  72 , thereby blocking or diverting water from entering the overflow tube  45   d.    
       FIG. 13  illustrates a preferred method  100  for refilling a siphonic bowl of a dual flush toilet. The method  100  comprises a step  110  of providing a relatively high flow of refill water from a refill tube to an overflow tube for a relatively short duration of time in response to a partial flush. This step  110  may comprise aligning the larger one of two holes with a refill tube, or refill tube connector, so as to enable a high flow rate of water to the overflow tube. Alternatively, this step  110  may comprise exposing the entirety or a majority portion of a single hole defined in a slide to a refill tube or a refill tube connector. The step  110  may further comprises opening or blocking water flowing from a refill tube to an overflow tube with a movable slide. 
     Step  120  includes providing a relatively low flow of refill water from the refill tube to the overflow tube for a relatively long duration of time in response to a full flush. This step  120  may comprise aligning the smaller one of two holes with a refill tube, or refill tube connector, so as to enable a low flow rate of water to the overflow tube. Alternatively, this step  120  may comprise partially blocking, or chocking, a single hole that is open to a refill tube or a refill tube connector. 
     Step  130  comprises filling the toilet bowl with an equal volume of water from the overflow tube in response to either the partial flush or the full flush. Thus, no matter which of the dual flush options is chosen, the toilet bowl will be filled with the same volume of water for an adequate refill while still conserving water. 
     Many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, it must be understood that the illustrated embodiments have been set forth only for the purposes of examples and that they should not be taken as limiting the invention as defined by the following claims. For example, notwithstanding the fact that the elements of a claim are set forth below in a certain combination, it must be expressly understood that the invention includes other combinations of fewer, more or different elements, which are disclosed in above even when not initially claimed in such combinations. 
     The words used in this specification to describe the invention and its various embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification the generic structure, material or acts of which they represent a single species. 
     The definitions of the words or elements of the following claims are, therefore, defined in this specification to not only include the combination of elements which are literally set forth. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements in the claims below or that a single element may be substituted for two or more elements in a claim. Although elements may be described above as acting in certain combinations and even initially claimed as such, it is to be expressly understood that one or more elements from a claimed combination can in some cases be excised from the combination and that the claimed combination may be directed to a subcombination or variation of a subcombination. 
     Insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the claims. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements. 
     The claims are thus to be understood to include what is specifically illustrated and described above, what is conceptionally equivalent, what can be obviously substituted and also what incorporates the essential idea of the invention.