The following text should not be construed as an admission of knowledge in the prior art. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.
Touchless automated hand-washing devices that incorporate rotating cylinders are known and have been in use for some time. These devices are designed to wash and/or provide a proper amount of anti-microbial solution to a person's hand and forearm within in a set time. The cylinders can be mounted in a free standing device and are adapted to receive the person's hand and forearm. The cylinders include an annulus or inner cavity that, in operation, is filled with cleaning fluid. As the inner cavity is filled, the cleaning fluid is forced out of a nozzle arrangement on the inner surface of the cylinder and into the interior of the cylinder. In order to provide greater coverage of the hand and forearm, the cylinders are rotated to provide a spray pattern.
A nozzle arrangement known in the prior art is disclosed by U.S. Pat. No. 4,817,651 (“the '651 patent”). This patent discloses a three-set grouping of nozzles positioned on the interior surface of the rotating cylinder. A first set of nozzles is positioned on a closed end of the cylinder opposite from an open end through which a person's hands are placed. The closed end includes a frusto-conical shape that allows the first set of nozzles to be positioned such that cleaning fluid is sprayed toward the user's hand. Additionally, the frusto-conical end portion may include a drain through which spent cleaning fluid may exit the cylinder. A second set of nozzles are arranged in a ring on the inner surface of the cylinder just inside the open end. The second set of nozzles are angled downward, such that their spray is directed into the cylinder. A third set of nozzles are positioned in a helical array along the length of the cylinder.
As described in the '651 patent, the three-set nozzle arrangement has several advantages. Firstly, the fingernails and the ends of the fingers receive a direct spray from the first set of nozzles. Secondly, the spray pattern that results from the second set of nozzles produces a “curtain” that prevents the cleaning fluid from being splashed or sprayed out of the cylinder. Lastly, the helical arrangement of nozzles along the length of the cylinder in combination the rotation of the cylinders results in debris and spent cleaning fluid being swept downward, toward the closed end of the cylinder. In particular, the third set of nozzles are disposed in a left-hand helical pattern which, when combined with the clock-wise rotation of the cylinders, results in a succession of sprays that travel down the arm from above the wrist towards the fingertips.
The spray pattern that results from the nozzle arrangement depends in part on the orientation and spray pattern of the individual nozzles. While the '651 patent contains little discussion of these details, U.S. Pat. No. 5,823,447 (“the '447 patent”) is directed to an angled fan nozzle for use with a rotating cleaning cylinder. The nozzle construction disclosed in the '447 patent produces a flat “fan” pattern. In particular, cleaning fluid is ejected into the interior of the cylinder from a nozzle having a small square aperture. The spray of cleaning fluid spreads out through an angle while remaining substantially in a single plane. The nozzle is constructed such that the plane of the fan spray pattern is angled at 15 degrees with respect to the axis of the nozzle. As described by in the '447 patent, the nozzle may be positioned on the interior of the cylinder at a 15 degree tilt towards the closed end of the cylinder. The 15 degree angle of the fan spray combines with the 15 degrees tilt of the nozzle, resulting in a fan spray directed partially downwards, towards the closed end of the cylinder. With respect to the plane of the cylinder opening, the fan spray is directed downward at a 30 degree angle. This downwardly angled fan spray operates to direct spent cleaning fluid downwards, towards the closed end of the cylinder.
While the '447 patent discloses an angle of the flat fan spray with respect to the plane of the cylinder opening, this reference is silent as to the rotational orientation of the fan spray pattern around with respect to the normal of the inner wall (or “roll” angle as defined later herein). For example, a particular nozzle may be positioned in a 0 degree rotational orientation, such that the flat fan spray is ejected from the nozzle “horizontally,” that is, in a plane parallel with the plane of the cylinder opening. Alternatively, a particular nozzle may be positioned in the 90 degree orientation such that the flat fan spray is ejected “vertically,” that is, in a plane perpendicular to the plane of the cylinder opening. As can be appreciated, a particular nozzle can be positioned at any angle between 0 and 90 degrees such that the flat fan spray has both a vertical and horizontal component.
It has been found that particular orientations and arrangements of nozzles not disclosed or suggested by the '651 patent or the '447 patent, such as the rotational orientation of particular nozzles, produce a novel spray pattern having increased coverage of the hand and forearm of the user. Additionally, the prior art fails to disclose other novel features associated with the cylinders that allow for faster and more reliable completion of wash cycles, safer operation, and easier assembly.
Nothing herein is to be construed as an admission that the present invention is not entitled to antedate a patent, publication or invention by another by virtue of prior invention.