This invention relates to blade sharpening or grinding devices.
There are in existence a number of sharpening or grinding machines specifically intended for use with trade knives, i.e. knives employed by tradesmen such as meat packers and butchers etc. These machines employ an electrically driven grinding wheel or an abrasive belt. Some of these machines also have a means of controlling the angle ground onto the knife blade edge, but none have any means of controlling the amount of material removed during grinding, this being left to the skill of the operator.
Thus, one known blade sharpener is little more than a bench grinder consisting of an abrasive wheel attached to the shaft of an electric motor. A blade guide is provided for offering a blade to the wheel at a particular angle, but no means of limiting the amount of material removed from the blade edge is provided.
A further known blade sharpener or grinding comprises an abrasive belt driven over two flanged pulleys, and again a blade guide for presenting a blade to the belt at a particular angle. The blade guide is adjustable to vary the angle of presentation. The blade edge is presented to a portion of the belt which runs over a rigid metal platten arranged between the two pulleys. Here again, there is provided no means of limiting the amount of material removed from the blade edge.