1. Field of Invention
This invention is in the area of paint equipment cleaning methods, specifically a paint roller cleaning method that uniformly wipes excess paint or solvent from rollers having different diameters and different nap thicknesses, that requires only one pass down the roller to effectively wipe the roller clean, and that can be easily used while the roller is on the roller frame.
2. Discussion of Prior Art
Paint roller cleaning methods are known in the art, and fall into five general categories:
A. Formed-Wire Roller Wipers
Formed-wire roller wipers, shown in U.S. Pat. No. 4,287,631 to Marrs and U.S. Pat. No. 5,335,392 to Evans, have inherent drawbacks, among the largest being that the wire lacks a flange-like surface to retain the paint below the wire as the device is drawn down the roller. Consequently, the wire does not force paint downward off the roller well enough, and excess paint can ride up over the wire as the device is drawn down the roller. Second, the formed wire, because of its round cross section, does not engage the nap surface of the roller squarely, and thus does not provide optimal wiping action. Third, the wire does not surround a large enough portion of the roller's outer circumference; hence, multiple passes are needed to effectively clean the roller. For all the above reasons, the wiping action of these devices is far from optimal.
Another key disadvantage of these devices is that they are not suitable for use with both standard diameter roller and "mini-size" rollers, since the roller-engaging curves in the wire are sized to optimally fit rollers of one diameter only. Marrs's device also exerts different degrees of spring tension, and hence friction, on rollers of different nap thicknesses, so that even different nap thicknesses of the same size roller cannot be wiped uniformly.
Finally, the device of Marrs cannot easily perform the wiping task in the optimal way--that is, wiping in a single pass from the handle end of the roller, down and off the non-handle end of the roller. Either the roller must be removed from its frame (dirtying the hands) to allow single-pass wiping, or the device must be placed on the non-handle end of the roller and wiped downward toward the handle end of the roller. This method of wiping tends to coat the roller handle and frame with paint wiped from the roller, which is not at all satisfactory. Moreover, Marrs's device must then be passed back up the roller to remove it--a cumbersome and unnecessary extra step.
B. Semi-Circular Roller Wipers
U.S. Pat. No. 4,324,018 to Olsson, U.S. Pat. No. 4,982,471 to Bannan, and U.S. Pat. No. 5,546,625 to Mealey, Sr. exemplify this type of roller wiper. These devices also have significant disadvantages.
First, because these devices do not surround a large enough portion of the roller circumference, multiple passes of the tool are necessary to effectively clean the roller.
Second, in operation the user must exert pressure with the tool against the roller while simultaneously moving the tool down the roller. This results in an uneven wiping action, particularly since multiple passes are necessary. It is difficult to exert the same pressure against the roller on each pass, and so a varying, uneven wiping action results.
Third, these devices cannot optimally clean both standard diameter rollers and "mini-size" rollers, since the roller-engaging curve in each device is sized to optimally fit rollers of one diameter only.
C. Fully-Circular Roller Wipers
U.S. Pat. No. 3,707,740 to Demers, U.S. Pat. No. 5,272,782 to Hutt, and U.S. Pat. No. 5,515,567 to Washburn are examples of this type of roller wiper. A key disadvantage of the devices of Hutt, Washburn, and the preferred embodiments (FIGS. 1-3) of Demers, is that they are not suitable for use with both standard diameter roller and "mini-size" rollers, since the roller-engaging aperture is sized to optimally fit rollers of one diameter only. Even different nap thicknesses of the same size roller cannot be handled optimally, since these devices exert different degrees of friction on rollers of different nap thicknesses.
The non-preferred embodiments (FIGS. 4-6) of Demers do provide for adjusting the diameter of the cleaning tool to handle different size rollers; however, the FIGS. 4-5 adjustment methods are cumbersome, time-consuming, and inconvenient to use.
A major drawback of all the embodiments of Demers is that they cannot easily perform the wiping task in the optimal way--that is, wiping in a single pass from the handle end of the roller, down and off the non-handle end of the roller. Either the roller must be removed from its frame (dirtying the hands) to allow single-pass wiping, or the device must be placed on the non-handle end of the roller and wiped downward toward the handle end of the roller. This method of wiping tends to coat the roller handle and frame with paint wiped from the roller, which is not at all satisfactory. Moreover, Demers's embodiments must then be passed back up the roller to remove them--a cumbersome and unnecessary extra step.
A further drawback of the device of Washburn is that it is difficult and time-consuming to place on the roller, and its multiple-piece construction is needlessly complex.
D. spinning-Type Roller Cleaners
U.S. Pat. No. 3,731,697 to Yost and U.S. Pat. No. 5,185,938 to Hutt are illustrative of this type of device, which spins the roller to centrifugally force off paint or solvent. These devices are complex and costly, and since the paint or solvent flies off the roller, they are also messy to use. Further, because these devices do not first wipe the excess paint from the roller, use of these devices does not save paint, nor does it reduce the use of solvent.
These devices also take a long time to remove the paint or solvent from the roller, since the centrifugal force they generate is inadequate to do the job quickly and effectively. In sum, these devices take longer to effectively clean the roller than would a cleaning method which uses my invention to first wipe excess paint from the roller, followed by a simple washing of the roller under a tap.
E. Roller Washers
These devices, shown in U.S. Pat. No. 4,061,153 to Doherty and U.S. Pat. No. 4,606,777 to Brow, spray or otherwise force solvent against the roller to achieve a cleaning action. Like the spinning-type roller cleaners discussed above, these devices are complex, costly, and messy. These devices also do not first wipe the excess paint from the roller; thus, using them will not save paint, nor will it reduce the use of solvent.
These devices also take a long time to remove the paint or solvent, since the excess paint is not first wiped from the roller. As with the spinning-type roller cleaners, these devices take longer to effectively clean the roller than would a cleaning method which uses my invention to first wipe excess paint from the roller, followed by a simple washing of the roller under a tap.
Thus, it can be appreciated that a paint roller cleaning method that uniformly wipes excess paint or solvent from rollers having different diameters and different nap thicknesses, that requires only one pass down the roller to effectively wipe the roller clean, and that can be easily used while the roller is on the roller frame, would be a significant improvement over the prior art.