Patent ID: 7854650
Filing Date: 2010-12-21
Classification: B24B

Abstract:
1. A knife sharpener comprising: a base defined with a receiving space for installation of grinding assemblies, a plurality of slots connecting with the receiving space being defined in a top surface of the base; a motor serving as a power source of the knife sharpener being assembled at one side of the receiving space; at least one grinding wheel assembly including two assembling members, a grinding disc and a grinding awl, each assembling member being provided with a bearing, the two assembling members being distantly disposed in the receiving space, so that the grinding disc is located between the two assembling members, the grinding disc has two surfaces, one of which is a grinding surface for grinding cutting edge, and a through hole formed in the middle of the grinding disc, the grinding awl being located between the two assembling members in such a manner that one surface of the grinding awl abuts against the grinding surface of the grinding disc, another surface of the grinding awl is rested against a fixing member, a surface of the grinding awl facing the grinding surface is a tapered grinding surface, which serves as another grinding surface of the knife sharper, a through hole formed in the middle of the grinding awl, the grinding disc and the edge of the grinding awl being located in a certain distance away from each other to form a working channel to be aligned with one of the slots; a rotary shaft having one end fixed to a rotor of the motor, so that it is rotated by the motor, another end of the rotary shaft in turn passing through the bearing of the assembling member, the through hole of the grinding awl, the through hole of the grinding disc and the bearing of another assembling member, so that the two bearings and the grinding awl are fixed on the rotary shaft, that the grinding disc is moveable along the rotary shaft, and the rotary shaft is able to rotate the grinding disc and the grinding awl to grind the knife; a spring is biased between the grinding disc and another fixing member, so as to keep the grinding surface of the grinding disc and the tapered grinding surface of the grinding awl close to each other under normal conditions, when the cutting edge of a knife is grinding in the working channel, the cutting edge can move the grinding disc to make the grinding surface and the tapered grinding surface move slightly in horizontal direction, while the tapered grinding surface can keep the cutting edge from overly moving downwards, so that the grinding surface and the tapered grinding surface can properly contact the cutting edge; three restricting ribs are distantly mounted in an inner surface of the receiving space, while three engaging grooves are formed in an edge of the assembling members and three engaging grooves are formed on an outer surface of a housing of the motor to mate with the restricting ribs, so that the assembling members and the motor are stably assembled in the receiving space.