Patent Publication Number: US-9410311-B2

Title: Dual flush device

Description:
RELATED APPLICATIONS 
     This application is a continuation application of U.S. Utility application Ser. No. 13/597,074 filed Aug. 28, 2012, now U.S. Pat. No. 8,850,630 which claims priority from U.S. Provisional Patent Application 61/528,666 filed Aug. 29, 2011 and from U.S. Provisional Patent Application 61/548,077 filed Oct. 17, 2011. 
    
    
     FIELD OF THE INVENTIONS 
     The inventions described below relate to the field of sanitation and more specifically to sanitary flush toilets. 
     BACKGROUND OF THE INVENTIONS 
     Conservation of fresh water is a worldwide concern. In developed countries a large portion of fresh water usage is used merely to flush toilets. Conventional dual flush toilets address this problem, but are expensive and generally require replacement of the flush mechanism in a toilet. 
     SUMMARY 
     The devices and methods described below provide for a dual flush toilet operable to perform two different flush actions; a small partial flush for liquid waste, and a second, full flush for solid waste. A new toilet or a conventional toilet are modified with the addition of a handle sleeve with a rotation stop and a lift arm extending through the handle sleeve with a rotation limiting tab on the lift arm to engage the rotation stop to enable the lift arm to rotate in a first direction through a first arc and to rotate in a second direction through a second arc where the first arc is smaller than the second arc. 
     A lift line extending from the offset distal end of the lift arm connects to the flapper or ball valve of the toilet. When the lift arm rotates through the first arc the flapper is raised to a first position resulting in a small partial flush for clearing liquid waste, and when the lift arm rotates through the second arc the flapper is raised to a second position resulting in a full flush for clearing solid waste. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view of a dual flush toilet. 
         FIG. 2  is a front view of the dual flush toilet of  FIG. 1 . 
         FIG. 3  is a side view of the dual flush toilet of  FIG. 1 . 
         FIG. 4  is a side view of a dual flush lift arm and handle assembly. 
         FIG. 5  is a top view of a toilet tank including the dual flush lift arm and handle assembly of  FIG. 4 , with the tank lid removed. 
         FIG. 6A  is an exploded view of the dual flush lift arm and handle assembly of  FIG. 4 . 
         FIG. 6B  is an end view from the handle end of the lift arm of  FIG. 6A . 
         FIG. 7  is an cross section view of the dual flush lift arm and handle assembly of  FIG. 4  taken along A-A. 
         FIG. 8  is a front view of a toilet tank with a front mounted dual flush lift arm. 
         FIG. 9  is a top view of the toilet tank of  FIG. 8  with the tank lid removed. 
         FIG. 10  is a top view of a dual flush toilet with a rounded tank. 
         FIG. 11  is a top view of the tank of the  FIG. 10  with the tank lid removed. 
         FIG. 12  is a top view of the tank of the  FIG. 10  with the tank lid removed to show an alternate handle arrangement. 
         FIG. 13  is a side view of a force redirection assembly. 
         FIG. 14  is a top view of the force redirection assembly of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTIONS 
     Dual Flush Toilet  10  of  FIGS. 1, 2 and 3  includes bowl  12  and tank  14  with side mounted lift arm assembly  15  and handle  16 . Tank  14  is enclosed and covered by tank lid  14 L. 
     Referring now to  FIGS. 4 and 5 , lift arm assembly  15  includes handle  16  secured to lift arm  17  which extends through handle sleeve  18 . Handle sleeve  18  includes flange  18 A secured to threaded sleeve  18 S. Flange  18 A may adopt any suitable ornamentation from a generally decorative style to a functional style. Distal end  18 D of threaded sleeve  18 S includes rotation stop  20 . Lift arm  17  has a generally straight main shaft  17 A and offset distal end  17 D. Main shaft  17 A includes rotation limiting tab  21 . Offset distal end  17 D includes one or more attachment holes such as holes  22 . 
     In use, lift arm assembly  15  is secured through an opening in a toilet tank such as hole  24  in tank  14 S using a lock nut  25  engaging threaded sleeve  18 S. Lift line  27  is secured between one of the attachment holes  22  and the flapper or ball valve  29 . Rotation of handle  16  in either a clockwise or counterclockwise direction causes offset distal end  17 D to rotate in a corresponding direction and pull lift line  27  which lifts flapper or ball valve  29  allowing water from the tank to flush the toilet. In a side handle tank such as tank  14 S, lift arm  17  is sized to orient distal offset end  17 D vertically above flapper valve  29  as shown. 
     Referring now to  FIGS. 6A and 6B , lift arm  17  has a generally cylindrical main shaft  17 A and an offset distal end  17 D. Offset length  30  and the size and orientation of rotation limiting tab  21  determine which direction of handle rotation results in a partial flush and which direction of handle rotation results in a full flush. Length  32  of main shaft  17 A may be adjustable to enable a single lift arm assembly to operate in a side handle or front handle toilet. Main shaft  17 A may telescope between rotation limiting tab  21  and first offset bend  17 B. Handle  16  may be attached to main shaft  17 A using any suitable attachment such as threads as shown in  FIG. 4  or an inset locking bolt or screw such as hex screw  19  through handle  16  into contact with main shaft  17 A. 
     Referring now to  FIG. 7 , rotation limiting tab  21  is secured to the main shaft of the lift arm to contact rotation stop  20  during counterclockwise rotation after rotating through a first, small arc  33 , and to contact rotation stop  20  during clockwise rotation after rotating through second arc  34  which is larger than the first arc. The orientation of rotation stop  20  and rotation limiting tab  21  may be reversed to achieve the same result. Handle  16  is generally aligned with offset distal end  17 D, and the normal rest position of both the handle and the offset distal end is at normal or rest position  35 . To achieve a partial flush, handle  16  is rotated through arc  33  until rotation limiting tab  21  contacts rotation stop  20  at position  36 . Rotation of the lift arm through first arc  33  causes offset distal end  17 D to rotate through the same arc, arc  33 . To achieve a full flush, handle  16  is rotated through second arc  34  until rotation limiting tab  21  contacts rotation stop  20  at full flush position  37 . Rotation of the lift arm through second arc  34  causes offset distal end  17 D to rotate through the same arc, arc  34 . 
     Tank  14 F of  FIGS. 8 and 9  is configured for a flush handle mounted on the front of the tank. In a retrofit situation, handle assembly  40  is generally located at a horizontal distance  41  from flapper valve  42 . As handle offset distance  41  grows, the efficiency of dual flush handle assembly  40  diminishes. For tank configurations with excessive handle offset distances, a force redirection assembly such as assembly  38  may be secured to tube  39 . Assembly  38  enables lift line  44  to apply the force from movement of the handle to be applied vertically or near vertically to flapper valve  42 . Any suitable means for securing the force redirection assembly to the tube may be used, such as adhesives, straps, clips and removable fasteners such as screws or pop rivets. Alternatively, dual flush efficiency may be improved by locating front mounted handle assembly  40 A closely over flapper valve  42  as shown. 
     In use, front mounted lift arm assembly  40  is secured toilet tank  14 F as discussed above. Lift line  44  is secured to one of the attachment holes  22  and extends through lift line channel or tube  38 T of the force redirection assembly and to the flapper or ball valve  42 . Rotation of handle  46  through the first small arc to position  47  causes offset distal end  17 D to rotate in a corresponding direction and pull lift line  44  into position  44 A which lifts flapper or ball valve  42  into first valve position  48 A allowing water from the tank to partially flush the toilet such as to clear liquid waste. Rotation of handle  46  through the second larger arc to position  49  causes offset distal end  17 D to rotate in a corresponding direction and pull lift line  44  into position  44 B which lifts flapper or ball valve  42  into second valve position  48 B allowing water from the tank to fully flush the toilet such as to clear solid waste. The length of lift line  44  also operates to limit the rotation of the lift arm and correspondingly handle  46  when performing a full flush. 
     Referring now to  FIGS. 10 and 11 , dual flush toilet  50  has a rounded tank  52  equipped with offset lift arm assembly  53  as discussed above. The curvature of tank  52  may necessitate the use of a tapered shim such as shim  54  to control the orientation of lift arm assembly  53  and minimize the effect of an excessive handle offset distance  51 . The tapered shims  54  and  54 A permit offset distal end  55  to be oriented above flapper valve  56  with minimal horizontal offset  57  between flapper valve  58  and offset distal end  55  of the lift arm. As discussed above, rotation of handle  59  clockwise through first small arc causes offset distal end  55  to rotate in a corresponding direction and pull lift line  58 L which lifts flapper or ball valve  58  into the first valve position allowing water from the tank to partially flush the toilet such as to clear liquid waste. Rotation of handle  59  counterclockwise through the second larger arc causes offset distal end  55  to rotate in a corresponding direction and pull lift line  58 L which lifts flapper or ball valve  58  into the second valve position allowing water from the tank to fully flush the toilet such as to clear solid waste. Any other suitable orientation of a rotation limiting tab and a rotation stop to generate a first small arc for a partial flush and a second larger arc to generate a full flush may be used. Alternatively, a force redirection assembly as shown in  FIGS. 8 and 9  may also be used. 
     Referring now to  FIG. 12 , for new toilets, mounting offset lift arm assembly  60  on the right side of the tank as viewed from the bowl side of the toilet permits offset distal end  61  to be oriented above flapper valve  62  with minimal horizontal offset  63  between flapper valve  62  and offset distal end  61  of the lift arm. As discussed above, rotation of handle  64  clockwise through first small arc causes offset distal end  61  to rotate in a corresponding direction and pull lift line  65  which lifts flapper or ball valve  62  into the first valve position allowing water from the tank to partially flush the toilet such as to clear liquid waste. Rotation of handle  64  counterclockwise through the second larger arc causes offset distal end  61  to rotate in a corresponding direction and pull lift line  65  which lifts flapper or ball valve  62  into the second valve position allowing water from the tank to fully flush the toilet such as to clear solid waste. Any other suitable orientation of a rotation limiting tab and a rotation stop to generate a first small arc for a partial flush and a second larger arc to generate a full flush may be used. 
     Force redirection assembly  70  of  FIGS. 13 and 14  is used when the handle offset distance  41  prevents efficient functioning of a dual flush device as occurs in retrofit situations as discussed with respect to  FIGS. 8 and 9 . Assembly  70  is secured to the fill tube in the toilet tank. Assembly  70  enables the lift line to apply the force from the handle vertically or near vertically to the flapper valve. Assembly body  72  includes slot  73  and is secured to a fill tube using attachment bracket  74 . Slot  73  permits cam  75  to be adjustably attached to body  72  with the ability to translate cam  75  along body axis  76 . Cam  75  may also be rotated about attachment bolt  77 . Cam  75  includes channel  78  to control and direct the lift line. 
     While the preferred embodiments of the devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the inventions. The elements of the various embodiments may be incorporated into each of the other species to obtain the benefits of those elements in combination with such other species, and the various beneficial features may be employed in embodiments alone or in combination with each other. Other embodiments and configurations may be devised without departing from the spirit of the inventions and the scope of the appended claims.