Cutting implements, such as knives, are widely used. For accuracy and uniformity of the slices of food to be cut, certain knives such as bread knives are commonly provided with a guide or gage spaced apart from the blade. Prior art knives having a blade guide generally fall into two categories. Those with the guide attached at two distal points on the blade, and those in which the guide is supported at only one of its ends thereby forming a cantilever beam structure.
An example of a knife having a guide attached at both ends is illustrated in U.S. Pat. No. 127,998 issued Jun. 18, 1872 to Vickory. Vickory discloses a knife having a blade guard which can be placed at discrete positions relative to the blade. While simple in construction, in addition to offering only a limited number of selections to the user, adjusting the spacing between the guard and the blade requires the use of both hands.
Another example of an adjustable knife guide attached at both ends of the blade is illustrated in U.S. Pat. No. 1,470,147 issued Oct. 9, 1923 to Clawson. Clawson discloses a knife having a spring-biased guide extending below the plane of the cutting edge of the knife. This construction allows the user to place the guide in abutting relationship with the food to be sliced. Toward the end of the slicing operation, i.e., when the guide comes into contact with the surface on which the item to be cut is placed, the spring-biased guide yields under the downward force exerted by the user so that the slice can be cut all the way through. Although the spring-biased guide aids the user in positioning the knife relatively accurately with respect to the food to be cut, in order to adjust the spacing between the guide and the blade, the user, using both hands, must remove the fasteners that secure the guide support members to the blade, separate the spring-biased guide from the blade, and insert different size washers between the guide support members and the blade before reattaching the guide to the blade.
In addition to the limitations described above, in knives having a blade guide attached at both ends, the food being sliced has a tendency to get caught between the blade and the guide. Accordingly, to overcome some of these shortcomings, in certain prior knives with adjustable guide the guide is attached to the blade only at the end proximate to the handle. In such cantilever beam construction, disengaging the knife from the item to be cut can be achieve simply by pulling the knife back toward the user. A cantilever-type guide also typically allows the user to adjust the spacing of the guide more conveniently.
U.S. Pat. No. 1,069,189 issued Aug. 5, 1913 to Saltzman discloses a knife having a cantilever guide. The guide is attached to the knife by means of a U-shaped member configured to fit over the top edge of the blade. The U-shaped member includes a stem integrally formed with and extending from the member. The stem is threaded both internally and externally. The internally threaded bore receives a set screw which secures the U-shaped member to the blade. The spacing between the blade and the guide can be adjusted by rotation of a nut mounted onto the externally threaded stem. The nut also has a series of longitudinally extending grooves at spaced locations along its circumference which are designed to receive a spring finger to prevent accidental rotation of the nut.
In Saltzman, to adjust the guide the user, nesting the handle in one hand, first disengages the spring finger from a groove using the other hand and then rotates the nut along the threaded bolt until the guide is at the desired position with respect to the blade. The user then locks the guide into position by engaging the spring finger in a groove of the nut. Although the free end of the guide permits the user to easily remove the cut slices, both hands are required to adjust the guide. As one will readily appreciate from the foregoing, the knife of Saltzman includes a significant number of components. In addition to increasing the cost of such an item, such a structure makes it more difficult for the user to clean the knife and to keep it free of food crumbs and other particles.
U.S. Pat. No. 3,110,964 issued Nov. 19, 1963 to Szekely also discloses a knife with adjustable guide having a free end and a threaded knob at the opposed end of the guide to adjust the spacing between the guide and the blade. The guide mechanism comprises several parts including a housing, a guiding member, a screw assembly and associated components. Furthermore, since the knob is positioned on a side of the handle, the user will more likely need to use both hands to adjust the position of the guide.
Finally, another example of a knife having a cantilever guide is disclosed in U.S. Pat. No. 3,178,817 issued Apr. 20, 1965 to Rubinstein. In Rubinstein, the adjustable guide is secured to a side of the knife handle by a channel-shaped bracket. The guide is provided with an eye at the guided end, the eye being threaded to receive the stem of a screw which is rotatable by means of a knob disposed on the side of the handle. The eye of the blade guide is guided within the channel of the bracket, thereby allowing the user to adjust the spacing between the guide and the blade by rotation of the knob. Because the knob is disposed closer to the handle than in Szekely, adjusting the guide will be somewhat facilitated.
It is apparent from the foregoing that the knives disclosed in Szekely and Rubinstein benefit from the essential advantage afforded by knives with cantilever-type guides, i.e., they permit the user to more conveniently disengage the knife after a slice of food has been cut. Although these knives also facilitate the adjustment of the guide with respect to the handle, the items disclosed in these two patents still suffer from the fact that they include several components which may be relatively difficult to keep clean.
The limitations identified in the foregoing make apparent that prior art knives provided with an adjustable guide are not fully satisfactory. Thus, it appears desirable to provide a knife with a cantilever-type adjustable guide having improved features that alleviate the shortcomings associated with conventional prior items, but which is nevertheless engineered to facilitate its fabrication, at the same time improving, or at least maintaining, its reliability and relatively low cost.
USPTO Backgrounds
USPTO Backgrounds