Referring to
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
As shown in
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 mm2/s at 100° C. and 7,414 mm2/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.
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.
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”.
| Number | Date | Country | |
|---|---|---|---|
| 60793559 | Apr 2006 | US |