US1793171A

US1793171A - Knife blade

Info

Publication number: US1793171A
Application number: US426409A
Authority: US
Inventors: Grant William
Original assignee: Individual
Current assignee: Individual
Priority date: 1929-02-16
Filing date: 1930-02-06
Publication date: 1931-02-17
Anticipated expiration: 1948-02-17

Description

w. GRANT- 1mm:` BLADE Filed Fon. 6.,..1950

fama/wwf@ patented Feb. 17, i931 UNITED sArEs PATENT ori-'ICE l GRANT, F SHEFFIMJD, ENGLAND i KNEE BLADE Application led February 8, 1980, Serial No. 426,409, and in Great britain February 16, 1929..

This invention relates to lrnie blades of termined by the general shape of the blade. the type in which aseries of grooves is ground A series of grooves in the form of rounded in one or both of the blade surfaces adjacent depressions 8 is then ground in one or both to the cutting edge, the object of the invenof the blade'surfaces to meet the edge 7 withtion being to provide an improved formation out intersecting it. As shown in the drawin le of cutting edge which is particularly applieach of the groove depressions 8 is of a roun cable for use 1n cutting tomatoes, fruit and ed Outline extending from the cutting edge 7 the like, although the invention may be yapand the surface enclosed by the outline is also plied with advantage in other circumstances. of a rounded sha e. The groove de ressions Knife blades are known with closely ar- 8 are preferably ibrmed by means ofp a grindso ranged grooves of a narrow V-section proing disc or wheel having a rounded operative ducing a series of points on the blade edge edge. Although various sizes of grinding and it has been proposed to make the grooves discsl may be used the preferred size has a I of a rounded outline and of a semi-circular diameter of about three or four inches and a i section in one or both surfaces of the blade, thickness of about half an inch to three-q'uaro5 but such rounded grooves have been sepaters of an inch, its edge being approximately rated by substantial lengths of the ori 1inal semi-circular in transverse section. edge and all the known forms of grooves ave In order that the groove depressions 8 may been made to become gradually deeper tomeet the edge 7 without intersecting it they mi wards the cutting edge to intersect that edge are each made to become radually shallow- To and thus to form notches therein.Y According er towardsthe edge 7 as s own in Figure 3. to the present invention, however, the grooves The central portion of the base of this shalt l are in the form of rounded depressions havlowing part of the depression is thus at a ing rounded outlines disposed in close proxmore acute angle with the 'opposite surface irnity to one another and meeting the cutting of the blade than the one in which it is 75 edge of the blade without intersecting it so ground, andiis preferably substantially paralthat the edge retains its original shape. This lel to the opposite surface adjacent to the may be eilected by making each of the groove ed e as shown in Figure 3. depressions to become gradually shallower tis preferred to rovide the groove dew towards the cutting edge, preferably so that pressions 8 alternate y Ain both surfaces of so a part of the base of the depression is subthe blade as illustrated, those in one surface stantially parallel to the opposite surface of being situated between those in the other surthe blade adjacent to the edge., face. If desired, however, they may all be lnthe accompanying drawing z-n formed in one surface. Figure l is an elevation of a lrniie accordl As the groove depressions 8 are made to se in to the present invention. meet the cutting edge 7 without intersecting igure 2 is an elevation on an enlarged it as illustrated, this edge will retain its shape,

scale of part of a blade illustrating a slight but where each groove depression meets it, p niodicatiom preferably as a chord of a semi-circle as ill Fi ure 3 is a transverse section, exaggeratlustrated, there will be a region of thinner ce ing t e thickness for the sake of clearness, metal adjacent to the cutting edge producon the line 3-3 of Figure 2, and ing a razordilre ed e, whilst between the Figure t is a fra entary view looking at groove depressions t e normal blade structhe edge of the bladgurexn ture will provide the necessary strength and M Like reference numerals indicate like parts support. The groove depressions are diso5 throughout the drawing., posed in close proximity to one another in i In carrying out the present invention a one or both surfaces and may be practically miie blade 6 is irst ground to a normal cutcontiguous as illustrated in'Figure l, or they tin edge 7 having no substantial thickness may be separated by relatively short unan of the usual straight line or curve degrooved portions 9 of the blade as illustrated 100 2 y ifeaivi in Figure 2 to increase the portion of normal blade structure strengthening and supporting the razor edge produced by the formation of the groove depressions 8.

To obtain the best results from the present invention the size of the groove depressions 8 is an important factor. if they are too small there isa danger o producing a jagged saw-like edge, Whilst if they are too there Will be insuicient support given to the central portions of the razor-like cutting edge produced by the groove depressions. In the preferred forni and size the Width of the depression is a maximm at the cutting edge and this width is approximately a quarter of an inch, so that when the groove depressions are formed imboth surfaces of the blade the centre of one is se arated from the centre of the next one in t e same surface by approximately half an inch. This distance will, however, be slightly increased when adjacent groove depressions are sep arated by short ungrooved portions 9. The dimensions given may, however, be considerably varied without departing from the invention.

What l claim is l. A knife blade having a series of depres sions in its surface adjacent to the cutting edge and meeting that edge Without intersecting it, substantially as specified.

2. A knife blade having a series of rounded depressions having rounded outlines in its surface dis osed in close proximity to one another an meeting the cutting edge of the blade Without intersecting it, substantially as specified.

3. A knife blade having a series of round ed depressions having rounded outlines al ternately disposed in the two surfaces of the blade in close prorimity to one another and meeting the cutting edge of the blade Without intersecting it, substantially as specified.

4;. A knife blade having a series of depressions in its surface formed to become gradually shallovver towards the cutting edge and to meet that edge Without intersecting it, substantially as specified.

5. A knife blade having a series of depressions in its surface/meeting the cutting edge without intersecting it and having the central portion of the base of each de ression at a more acute angle with the opposite surface of the blade than the one in which it is formed, substantially as speciied.

6. A knife blade having a series of depressions in its surface formed to become radually shallovver towards the cutting edge to meet that edge Without intersecting it and with the base of such shallowing part substantially parallel to the opposite surtace of the blade adjacent to the edge, substantially as specified.

' 7. A knife blade having a series of rounded depressions having rounded outlines signature.

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