Presently, various commercial fruit and vegetable juicers are available for extracting juice from fruits or vegetables. These devices are generally powered by an electric motor and have a filter assembly comprised of either a frusto-conical or a columnar, bowl-like filter sieve. These juicers contain a rotatable horizontal grating disk positioned in the filter sieve such that the filter sieve walls extend up and/or away from a periphery of the grating disk. A cover may have a passageway formed therein allowing fruits or vegetables to be pushed or forced into contact with the grating disk. Such a food pusher forces the fruit or vegetable through the passageway onto the surface of the grating disk.
While typical juicers may efficiently extract juice from fruits or vegetables, dried or reduced pulp often clogs the filter, sometimes very quickly, and is difficult to remove from the filter sieve area after the juice has been extracted.
The prior art addressed this problem in various ways. As an example, U.S. Pat. No. 5,421,248, to Hsu, discloses a dreg or food residue removal feature in which a stopper element is positioned in the open interior space of the filter assembly.
As the filter assembly spins, the stopper is engaged at a certain position. The dregs collect against the stopper and are forced upwardly against the interior wall of the filter assembly into numerous compartments. The filter housing is bowl-shaped and has vertical side walls. The drawbacks of the Hsu structure is that dried dregs or food residue clog in the top cover assembly. The user must then remove the assembly and manually extraction of the dregs. Other problems experienced include increased building costs; increased complexity in the top cover of the juicer; and increased likelihood of component breakdown. U.S. Pat. No. 5,433,144, to Lee, also discloses a scraper that is disposed in the filter assembly and positioned to force dregs or residue up and out of the filter assembly and into a trash receptacle.
As another example, U.S. Pat. No. 4,506,601, to Ramirez et al., discloses a fruit and vegetable juicer having a frusto-conical filter basket. In Ramirez, a pulp discharge control means comprises a cylindrical rim or circular band having flexible vanes attached to the rim such that the vanes flex and extend radially outward due to centrifugal forces when the spindle rotates. The discharge means are disposed in the filter basket. As the filter basket spins, the vanes push outwardly and press the pulp against the filter basket. Eventually the pulp is forced up and discharged through an outlet duct. This configuration exhibits some of the same short-comings as described above. Dried pulp lodges in the outlet duct or under the top cover. The increased mechanical complexity of the pulp discharge element is costly to build and more susceptible to mechanical breakdown.
As another example, U.S. Pat. No. 4,700,621, to Elger, and U.S. Pat. No. 5,479,851, to McClean et al., both disclose a fruit and vegetable juicer having a frustro-conical filter basket and passageways which serve to direct pulp to a collection area. However, the pulp lodges in the top cover at various locations. In Elger, the pulp creeps up the surface of the filter basket and must be caught in a "pulp trough." The top cover assembly still must periodically be removed to clean out the passageways and underside of the top cover to further use the juicer.
Similarly, in McClean et al., the top cover 15 can easily clog as pulp is extracted from the filter basket. The McClean cover provides little space and no efficient guiding surfaces to control the pulp extraction path. This can be understood from FIG. 3 of the reference.