Method of and apparatus for forming perforated shear plates for dry shavers of the rotary type

Claim 1

THE METHOD OF PRODUCING FROM A THIN FLAT IMPERFORATE CIRCULAR BLANK, A SHEAR PLATE HAVING AN OFFSET LATERAL CONCAVO-CONVEX TORUS EXTENDING THEREAROUND AND PERFORATED TO PROVIDE TWO ROWS OF CIRCUMFERENTIALLY SPACED ELONGATED SHEAR PERFORATIONS, ONE ON EACH SIDE OF THE TORUS CREST, SAID METHOD COMPRISING FORMING IN SAID BLANK TWO CONCENTRIC CIRCULAR ROWS OF SPACED PARALLEL ELONGATED SLOTS WITH AN INTERVENING ANNULUS THEREBETWEEN, SAID SLOTS BEING ARRANGED IN PAIRS, ONE ON EACH SIDE OF THE ANNULUS WITH THE AXES OF EACH PAIR OF SLOTS BEING INCLINED RELATIVELY TO EACH OTHER, AND THEREAFTER SHIFTING SAID ANNULUS BODILY RELATIVELY TO THE PORTIONS OF THE BLANK EXISTING RADIALLY OUTWARDLY AND RADIALLY INWARDLY OF THE ROWS OF SLOTS CIRCUMFERENTIALLY ABOUT THE CENTRAL AXIS OF THE BLANK WHILE SIMULTANEOUSLY FORCING THE SAME AXIALLY IN ONE DIRECTION OUT OF THE PLANE OF THE BLANK AND INTO COINCIDENCE WITH THE CREST PORTION OF THE TORUS OUTLINE, WHILE AT THE SAME TIME, AND AS A RESULT OF SUCH SHIFTING AND FORCING, APPLYING DEFORMING PRESSURE TO THE MATERIAL OF THE BLANK IMMEDIATELY SURROUNDING THE ROWS OF SLOTS SO AS TO BRING THE SAME INTO COINCIDENCE WITH THE REMAINDER OF THE TORUS OUTLINE, TO THUS ESTABLISH THE TORUS AND SHEAR PERFORATIONS THEREIN.

Claim 2

THE METHOD OF PRODUCING FROM A THIN FLAT IMPERFORATE CIRCULAR BLANK, A SHEAR PLATE HAVING AN OFFSET LATERAL CONCAVO-CONVEX TORUS EXTENDING THEREAROUND AND PERFORATED TO PROVIDE TWO ROWS OF CIRCUMFERENTIALLY SPACED ELONGATED SHEAR PERFORATIONS, ONE ON EACH SIDE OF THE TORUS CREST, SAID METHOD COMPRISING FORMING IN SAID BLANK TWO CONCENTRIC CIRCULAR ROWS OF SPACED PARALLEL ELONGATED SLOTS WITH AN INTERVENING ANNULUS THEREBETWEEN, SAID SLOTS BEING ARRANGED IN PAIRS, ONE ON EACH SIDE OF THE ANNULUS WITH THE AXES OF EACH PAIR OF SLOTS BEING INCLINED RELATIVELY TO EACH OTHER, AND THEREAFTER SHIFTING SAID ANNULUS BODILY RELATIVELY TO THE PORTIONS OF THE BLANK EXISTING RADIALLY OUTWARDLY AND RADIALLY INWARDLY OF THE ROWS OF SLOTS CIRCUMFERENTIALLY ABOUT THE CENTRAL AXIS OF THE BLANK WHILE SIMULTANEOUSLY FORCING THE SAME AXIALLY IN ONE DIRECTION OUT OF THE PLANE OF THE BLANK AND INTO COINCIDENCE WITH THE CREST PORTION OF THE TORUS OUTLINE, WHILE AT THE SAME TIME, AND AS A RESULT OF SUCH SHIFTING AND FORCING, APPLYING DEFORMING PRESSURE TO THE MATERIAL OF THE BLANK IMMEDIATELY SURROUNDING THE ROWS OF SLOTS SO AS TO BRING THE SAME INTO COINCIDENCE WITH THE REMAINDER OF THE TORUS OUTLINE, TO THUS ESTABLISH THE TORUS AND SHEAR PERFORATIONS THEREIN.