Patent Abstract:
A trip lever assembly for initiating a flush cycle of a toilet is constructed to have a more solid and smooth feel with less play. The assembly includes a handle accessible with a stem extending into an interior of the toilet. An inner bushing fits onto the stem and inside of a fixed outer bushing. A trip arm connect the handle to a pull member operatively attached to the flush valve. The handle has an anti-rotation feature that engages an associated feature of the inner bushing so that the inner bushing mechanically couples and rotates with the handle. A high viscosity dampening grease is disposed between the inner bushing and the outer bushing to limit lateral play, and smooth the rotation of the handle.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority to U.S. provisional patent application Ser. No. 60/793,559, filed on Apr. 20, 2006, and entitled “Trip Lever Assembly”. 

   STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable. 
   BACKGROUND OF THE INVENTION 
   The present invention relates to toilet trip lever assemblies. 
   Plumbing fixtures such as toilets for cleaning and eliminating waste are well known. The flush cycle of toilet is initiated by a user depressing the handle of the trip lever at the outside of the toilet tank. This causes a trip arm inside of the tank to raise a pull chain which pulls the movable member of a flush valve (such as a flapper member) upward and unseat. When the valve is unseat, water from the tank is permitted to rush into the bowl and cause it to flush the waste and water therein into the waste plumbing lines of the building. 
   One problem with conventional trip lever assemblies is that they are often manufactured with very loose tolerances and thus provide a sloppy feel and appearance to the user, and they can also rattle and make other noises, especially when the handle is rotated back to its initial position. These problems can give the user an impression that the fixture is low-budget or poorly constructed. 
   Hence, a need exists to provide an improved trip lever assembly that provides a more solid feel and smoother rotational motion of the handle. 
   SUMMARY OF THE INVENTION 
   The invention provides a trip lever assembly designed to provide an improved feel with less play and smoother rotational motion. The assembly has a stemmed handle supporting two bushings. Close tolerances and a positive mechanical connection are achieved between the inner bushing and the handle to limit play between these components. A high viscosity dampening material can be applied between the inner and outer bushings to further reduce play, particularly in the lateral direction, as well as smooth out the rotation of the handle and return the handle to its initial, resting position in a slow, smooth stroke. 
   In one aspect, the invention thus provides a trip lever assembly, for initiating a flush cycle of a toilet, having a handle, a trip arm, an inner bushing and an outer bushing. The handle is accessible from an exterior of the toilet and has a stem extending into an interior of the toilet along a pivot axis. The trip arm is linked to the stem for rotation by the handle about the pivot axis. The inner bushing mounts onto the stem and the outer bushing mounts onto the inner bushing. The outer bushing is held in a fixed position and the inner bushing is mechanically linked to the handle to rotate with the handle relative to the outer bushing. 
   The inner bushing is linked to the handle by an anti-rotation feature, or combination of two or more features, preventing relative rotation between the inner bushing and the handle. The anti-rotation feature(s), for example, can be a tab and slot arrangement, such as a raised tab of the handle and a slot of the inner bushing. Preferably, then the tab is disposed in a radial orientation at a base of the stem and the slot is disposed at a flange end of the bushing. However, other constructions for the anti-rotation feature(s) are within the scope of the invention, for example, mating multi-sided or serpentine edges surfaces of the handle and inner bushing. 
   In addition to the positive mechanical connection between the inner bushing and the handle, other features of the trip lever assembly help to achieve a high integrity handle with a solid connection and smooth rotational motion. For instance, handle can be a metal (and thus more weighty) while low cost, plastics can be used for the bushings. The distal end of the stem can have an anti-rotation feature that is matable with the trip arm to prevent relative rotation therebetween. Also, the inner bushing can have one or more crushable ribs at an interior surface that deform as the stem is inserted into the inner bushing, thereby taking up any gap from manufacturing tolerances that would otherwise give the assembly a loose connection. Further, a dampening material, such as a high viscosity greased, can be disposed between the inner and outer bushings. This will further reduce play in the lateral direction perpendicular to the pivot axis. More importantly, it will smooth the rotational motion of the handle and work to slow the return of the handle to its initial position, thereby giving the handle a high integrity appearance, as if controlled or mounted by a more complex rotational system, such as a bearing or other such component. 
   In another aspect the trip lever assembly has a handle accessible from an exterior of the toilet and a stem extending into an interior of the toilet along a pivot axis. The handle rotates a trip arm and has a first anti-rotation feature that engages with a second anti-rotation feature of an inner bushing mounted about the stem to cause the inner bushing to rotate with the handle. An outer bushing is mounted about the inner bushing in a fixed position (as when mounted to a fixed object inside the toilet) to allow for relative rotation between the inner and outer bushings. A dampening material, such as a high viscosity dampening grease, is disposed between the inner bushing and the outer bushing. 
   Other advantages of the invention will be apparent from the detailed description which follows and accompanying drawings. What follows is merely a description of a preferred embodiment of the present invention. To assess the full scope of the invention the claims should be looked to as the preferred embodiment is not intended to be the only embodiment within the scope of the claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is perspective view of a trip lever assembly according to the present invention; 
       FIG. 2  is an exploded assembly view of a handle and inner bushing of the trip lever assembly of  FIG. 1 ; 
       FIG. 3  is a partial sectional view taken along line  3 - 3  of  FIG. 1 ; and 
       FIG. 4  is a sectional view taken along line  4 - 4  of  FIG. 3 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  illustrates an exemplary trip lever assembly  10  of the present invention for initiating the flush cycle of a toilet (not shown). The trip lever assembly  10  can be used by the user to operate the flush valve of a conventional toilet, for example, by being linked to the pull cord or chain (not shown) connected to the movable part of the flush valve, such as a flapper member (not shown), to unseat the movable part and commence a flow of water from the tank into the bowl of the toilet. As described below, in addition to providing the basic operational functions, the trip lever assembly  10  has several features that make it a high integrity assembly with a more solid feel with less play and smooth rotational motion. 
   Referring to  FIGS. 1-3 , the trip lever assembly  10  includes a handle  12 , an inner bushing  14  (see  FIG. 2 ), an outer bushing  16  and a trip arm  18 . The handle  12  is preferably a finished and polished metal or other such material with high aesthetic value and solid feel. The handle  12  has a lever end  20  for gripping by the user that extends from a round hub  22  from which a stem  24  extends perpendicularly to the lever end  20 . The handle  12  mounts to the toilet tank (via the outer bushing  16  as described below) at an opening therein (not shown) so that the hub  22  and lever end  20  are outside of the tank and the stem  24  extends inside of the tank. The stem  24  extends along a pivot axis  26  and has a circular cross-section perpendicular to the pivot axis  26  that tapers to a distal end  28  with about a one degree draft between its ends. 
   The stem  24  fits snuggly inside of the inner bushing  14 , which has a tapered, circular cross-section inner surface to mate with the stem  24 . The symmetric geometry of the stem  24  and inner bushing  14  permits the stem  24  to be fit into the inner bushing  14  irrespective of relative orientations as well as reduces warping of the inner bushing  14  during use. The inner bushing  14  (and the outer bushing  16 ) are preferably a suitable plastic. As shown in  FIG. 4 , the inner bushing  14  also has three crushable ribs  30  at its inner surface that extend in the axial direction and are spaced angularly about the pivot axis  26 . The ribs  30  are short and narrow so that the deform when the stem  24  is fit inside the inner bushing  14 . The ribs  30  thus take up any gap that may arise from manufacturing tolerances or inconsistencies to achieve a very tight fit between the parts and reduce play and/or rattle. The symmetric angular arrangement of the ribs  30  also works to center the stem  24  inside the inner bushing  14 . 
   As shown in  FIGS. 2 and 3 , the inner bushing  14  has a radial flange  32  at its wider end that includes an anti-rotation feature  34  that mates with an anti-rotation feature  36  of the handle  12 . In the preferred embodiment shown and described herein, the anti-rotation feature  34  is a small radially oriented open-ended notch or slot that is sized to receive a small radially oriented boss or tab formed integrally with the handle  12  at the base of the stem  24 . This tab and slot arrangement creates a positive mechanical connection between the handle  12  and the inner bushing  14  so that the inner bushing  14  rotates with the handle  12  with very little or no relative rotation therebetween. The anti-rotation features  34  and  36  thus work to achieve a tight, low-play connection between the handle  12  and the inner bushing  14 . 
   As mentioned, the aforementioned tab and slot arrangement is only one preferred constructions, and other arrangements may be suitable to achieve a positive mechanical connection between the handle  12  and the inner bushing  14 , for example, a multi-sided or convoluted edge surface or shoulder extending about the base of the stem  24  that mates with a complementary edge surface at the proximal end of the inner bushing  14 . The anti-rotation feature may also be achieved by a protrusion on the handle  12  that “digs” directly into the softer plastic material of the inner bushing  14 , without a corresponding opening or mating feature being formed in or on the inner bushing  14 . 
   The outer surface of the inner bushing  14  can be is tapered, or more preferably it is straight (non-tapered or cylindrical) with flats (not shown) formed symmetrically about the parting line so as to minimize the effects of “flash” on the cylindrical symmetry of inner bushing  14 . The inner bushing  14  is stepped down near its distal end and has a small ring-shaped edge rib  40  that is crushable during assembly to provide a compressive fit between the handle (via the inner bushing  14 ) and the trip arm  18 . 
   The inner surface of the outer bushing  16  is shaped to match the outer geometry of the inner bushing  14  with a small diametrical gap, for example 0.0001 to 0.010 inches therebetween. The small gap provides space for a dampening material to be disposed between the inner bushing  14  and the outer bushing  16 . The purpose of the dampening material is preferably two-fold. The dampening material should work to take up play that may otherwise exist in the lateral direction of the assembly, that is in the direction perpendicular to the pivot axis  26 , thereby further provide for a tight, solid connection. It also lubricates the bushings to permit rotational motion with more limited effects of static and dynamic friction. With sufficiently high viscosity dampening material, the handle  12  will turn in a very smooth, but robust and solid feeling motion, and it will return to its initial resting position in a slower and smoother stroke than it would otherwise. An example of a suitable dampening material is a dampening grease, such as Nye Nyogel® 774H commercially available from Nye Lubricants, Inc. of Fairhaven, Mass., which preferably has a kinematic viscosity of 668 mm 2 /s at 100° C. and 7,414 mm 2 /s at 40° C. 
   The trip arm  18  mounts to the distal end of the handle stem  24  by a bolt  42 . While shown round, the distal end of the stem  24  can have an anti-rotation feature, in the form of a squared surface extending about the opening receiving the bolt  42 , that ensures that the trip arm  18  rotates with the handle  12  without slipping. 
   The entire assembly  10  mounts to the toilet tank so that the handle  12  is outside of the tank and the handle stem  24 , inner  14  and outer  16  bushings, and trip arm  18  are inside the tank. The outer bushing  16  has external threads  50  that fixed it in place so as not to rotate with the handle  12 , inner bushing  14  or the trip arm  18 . 
   As is conventional, the free end of the trip arm  18  is connected to a pull chain or chord via opening  52  so that when the handle is pushed down, the trip arm  18  pivots upward and pulls the pull chain/chord upward to lift the flush valve (such as a conventional flapper) off of the valve seat. This begins the flush cycle. Afterward, the flush valve will close under gravity and the trip arm  18  will pivot downward under gravity. At the same time, the handle  12  will return to its initial position in a slow, smooth motion. The rotation angle of the handle  12  is limited to 90 degrees by interference of an internal rib of the handle  12  with a 270 degree shoulder  56  at the end of the outer bushing  16  opposite the trip arm  18 . 
   While there has been shown and described what is at present considered a preferred embodiment of the invention, various changes and modifications can be made therein without departing from the scope of the invention defined by the appended claims. Therefore, various alternatives and revised embodiments are contemplated as being within the scope of the following claims. 
   INDUSTRIAL APPLICABILITY 
   The invention provides a trip lever assembly having an improved feel with less play and smoother rotational motion. Close tolerances and a positive mechanical connection are achieved between the handle can be inner bushing and the handle to limit play between these components. A high viscosity dampening material can be applied between the inner and outer bushings to further reduce play, particularly in the lateral direction, as well as smooth out the rotation of the handle and return the handle to its initial, resting position in a slow, smooth stroke.

Technology Classification (CPC): 4