NZ202770A - Knife blade with minor scallops in each major scallop - Google Patents

Description

2 02770 Priority Date(s): .. ........

Complete Specification Filed: Ctass: .. &?-!P&.'VP?r PubHcation Date: ^■8SEP-lcj84 P.O. Journal, No: . . ........

NEW ZEALAND PATENTS ACT, 1953 ,J&2. PATSftfT qpptcl | 10DEC1982 COMPLETE SPECIFICATION ^ RECEfVEO " IMPROVEMENT IN KNIVES Wet WILKINSON SWORD LIMITED, a British company, of Sword House, Totteridge Road, High Wycombe, Buckinghamshire, England hereby declare the invention for whioh we pray that a patent may be granted to us, and the method by which it is to be performed3 to be particularly described in and by the following statement: (foil owed by page -la-) No: Date: 202770 IMPROVEMENT IN KNIVES This invention relates to knives, and in particular to bread-slicing knives, hereinafter referred to occasionally as bread slicers.

Bread slicers are conventionally made with a straight serrated edge, the serrations being sharp and closely spaced so that the slicer performs a sawing action on the bread. This however tends to produce crumbs.

Bread slicers are also well known of the type having a cutting edge formed by a series of scallops, i.e. arcuate recesses, along the blade edge, each recess having a cutting edge over its peripheral length. This construction results in a vibrating action in the plane of the blade as the edge of the slicer is moved across a loaf of bread, and this vibratory action assists in cutting.

It has been proposed to combine the scalloped edge and the serrated edge, but such a construction does not remove the disadvantage of a serrated edge as described above.

According to the present invention there is provided a 2 202770 knife having a scalloped cutting edge, said edge comprising a series of major scallops, each said major scallop containing a plurality of minor scallops.

One form of knife according to the invention is illustrated in the accompanying drawing in which: Figure 1 is a side elevation of the knife? Figure 2 is a side elevation of a portion of the knife of Figure 1 to an enlarged scale; Figure 3 is an elevation of the knife portion of Figure 2 as seen from the opposite side, and Figure 4 is a cross section through the knife.

The knife, or bread slicer, 10 shown in the drawing, has a handle 9 and a blade 11, the blade having a cutting edge formed by a contiguous series of major scallops 12, each major scallop being made up of a contiguous series of minor scallops 13. Although three minor scallops is the proposed number in each major scallop, the number may be less than or greater than three, but if the number increases much above three, the benefits of the invention are reduced. 202770 3 As seen in side view, with the edge directed upwardly, the Knife edge has a range of major peaks 14 equidistantly spaced apart, with two minor peaks 15, between and below the major peaks, the major and minor peaks defining the ends of the minor scallops. All the peaks are nearly equidistantly spaced apart, and all are smoothly rounded. Thus within each major scallop, an imaginary circular arc can be drawn from one major peak 14 to the next major peak, on which the two minor peaks lie.

By way of example each pair of adjacent major peaks can be spaced apart by 0.311 inch (7.9mm), whereas the spacing between the two minor peaks in each major scallop is 0.110 inch (2.8mm), these minor peaks being equidistant from the major peaks. The radius of curvature of the cutting edge between adjacent minor peaks can be for example 0.047 inch (1.2mm).

If one takes as a reference base line, a straight line A-A tangent to the cutting edge between adjacent minor peaks, the perpendicular distance from each major peak 14 to the line A-A is 0.058 inch (1.48mm) and the perpendicular distance from each of the minor peaks 15 to the line A-A is 0.029 inch (0.74mm). Moreover, the radius of a circular arc passing through the major peaks 2 027 4 peaks and to which line A-A is a tangent is 0.252 inch (6.4mm).

As seen in the cross-section of Figure 4, the blade has a major chamfer 16 on each side extending over a distance of about 0.315 inch (8mm) from the straight line which formed the knife edge before grinding. In addition, on one side of the blade as seen in Figure 3, the blade has a series of minor chamfers 17 produced by grinding the cutting edge of each minor scallop with a grinding wheel.

This knife construction has been shown to have an improved cutting action over the simple scalloped edge without the disadvantages of the serrated edge. It is believed that this advantage may result from a compound vibratory action produced by superimposing a vibratory action resulting from the minor scallops on a lower frequency vibratory action produced by the major scallops. These vibratory actions are cutting actions resulting from the multiplicity of cutting edges, as distinct from sawing actions produced by a multiplicity of saw teeth.

Claims (6)

2 027 70 % ,, _ AIk_ CLAIMS* WHAT CLAIM IS;

1. A knife having a scalloped cutting edge, said edge comprising a series of major scallops ' , 5 each said major scallop containing a plurality of minor scallops

2. A knife according to claim 1 wherein each major scallop is defined by a contiguous series of three minor 10 scallops.

3. A knife according to claim 1 wherein the minor scallops have cutting edges of substantially equal length. 15

4. A knife according to claim 2 wherein each minor scallop has a peak at each end and adjacent peaks are substantially equidistant from one another. 20

5. A knife according to claim 1 wherein the major scallops are arranged along said edge as a contiguous series.

6. A knife substantially as herein described with 25 reference to the accompanying drawings. 6223 »B;2JJK6~ HZ. PATENT OPgg p 10DEC1982 - / ///rJi&o? —^y if au'-honsed Agents. BECHIVED r A- J' & SON. ■ aer«<-