Boning and trimming knife

Claim 2

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring blade housing having an axially elongated peripherally continuous portion adapted to be secured to a handle, to cover a blade-driving pinion in the handle, and to guide a continuous ring blade rotatable in the housing, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, said recess having two radially spaced concentric side wall surfaces one of which is a surface of revolution that forms the recess wider at the opening than interiorly thereof, and said housing having two peripherally spaced axially extending slots in the elongated portion opening through the other axial end.

Claim 3

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring blade housing having an axially elongated peripherally continuous portion adapted to be secured to a handle, to cover a blade-driving pinion in the handle, and to guide a continuous ring blade rotatable in the housing, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, said recess having two radially spaced concentric side wall surfaces one of which is cylindrical and the other of which is frusto-conical, said recess being widest at the recess opening, and said housing having two peripherally spaced axially extending slots in the elongated portion opening through the other axial end.

Claim 4

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring blade housing having an axially elongated peripherally continuous portion adapted to be secured to a handle, to cover a blade-driving pinion in the handle, and to guide a continuous ring blade rotatable in the housing, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, said recess having two radially spaced concentric side wall surfaces one of which is cylindrical and the other of which is frusto-conical, said recess being widest at the recess opening, and said housing having two peripherally spaced axially extending slots in the elongated portion opening through the other axial end.

Claim 5

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring blade housing having an axially elongated peripherally continuous portion adapted to be secured to a handle, to cover a blade-driving pinion in the handle, and to guide a continuous ring blade rotatable in the housing, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, said recess having two radially spaced concentric side wall surfaces, an inner one of which is a surface of revolution that forms the recess wider at the opening than interiorly thereof, and said housing having two peripherally spaced axially extending slots in the elongated portion opening through the other axial end.

Claim 6

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring blade housing having an axially elongated peripherally continuous portion adapted to be secured to a handle, to cover a blade-driving pinion in the handle, and to guide a continuous ring blade rotatable in the housing, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, said recess having two radially spaced concentric side wall surfaces, an inner one of which is a surface of revolution that forms the recess wider at the opening than interiorly thereof, and said housing having two peripherally spaced axially extending slots in the elongated portion opening through the other axial end.

Claim 7

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring blade housing having an axially elongated peripherally continuous portion adapted to be secured to a handle, to cover a blade-driving pinion in the handle, and to guide a continuous ring blade rotatable in the housing, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, said recess having two radially spaced concentric side wall surfaces, an outer one of which is cylindrical and an inner one of which is frusto-conical, said recess being widest at the recess opening, and said housing having two peripherally spaced axially extending slots in the elongated portion opening through the other axial end.

Claim 8

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring blade housing having an axially elongated peripherally continuous portion adapted to be secured to a handle, to cover a blade-driving pinion in the handle, and to guide a continuous ring blade rotatable in the housing, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, said recess having two radially spaced concentric side wall surfaces, an outer one of which is cylindrical and an inner one of which is frusto-conical, said recess being widest at the recess opening, and said housing having two peripherally spaced axially extending slots in the elongated portion opening through the other axial end.

Claim 9

A ring-like housing for guiding a rotary ring blade used for cutting meat and other suitable products, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, and having outer and inner spaced concentric circular wall surfaces engageable by the blade and spaced apart farther at said one axial end of the housing than inwardly thereof to allow assembly of the blade with the housing from the said one axial end, one of the said wall surfaces being a surface of revolution that forms the recess wider at the opening than interiorly thereof.

Claim 10

A ring-like housing for guiding a rotary ring blade used for cutting meat and other suitable products, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, and having outer and inner spaced concentric circular wall surfaces engageable by the blade and spaced apart farther at said one axial end of the housing than inwardly thereof to allow assembly of the blade with the housing from the said one axial end, one of the said wall surfaces being a surface of revolution that forms the recess wider at the opening than interiorly thereof.

Claim 11

A ring-like housing for guiding a rotary ring blade used for cutting meat and other suitable products, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, and having outer and inner spaced concentric circular wall surfaces engageable by the blade and spaced apart farther at said one axial end of the housing than inwardly thereof to allow assembly of the blade with the housing from the said one axial end, one of the said wall surfaces being cylindrical and the other being a surface of revolution that forms the recess wider at the opening than interiorly thereof.

Claim 12

A ring-like housing for guiding a rotary ring blade used for cutting meat and other suitable products, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, and having outer and inner spaced concentric circular wall surfaces engageable by the blade and spaced apart farther at said one axial end of the housing than inwardly thereof to allow assembly of the blade with the housing from the said one axial end, one of the said wall surfaces being cylindrical and the other being a surface of revolution that forms the recess wider at the opening than interiorly thereof.

Claim 13

A ring-like housing as set forth in claim 6 wherein said outer wall surface is cylindrical and said inner wall surface is frusto-conical.

Claim 14

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring-like blade housing adapted to be secured to a handle and to guide a continuous ring blade rotatable in the housing, said housing having two axial ends and an outer periphery, an arcuate recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, and having two spaced concentric arcuate wall surfaces engageable by the blade, one of said surfaces being a surface of revolution that forms the recess wider at the opening than interiorly thereof.

Claim 15

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring-like blade housing adapted to be secured to a handle and to guide a continuous ring blade rotatable in the housing, said housing having two axial ends and an outer periphery, an arcuate recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, and having two spaced concentric arcuate wall surfaces engageable by the blade, one of said surfaces being a surface of revolution that forms the recess wider at the opening than interiorly thereof.

Claim 16

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring-like blade housing adapted to be secured to a handle and to guide a continuous ring blade rotatable in the housing, said housing having two axial ends and an outer periphery, an arcuate recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, and having two spaced concentric arcuate wall surfaces engageable by the blade, one of said surfaces being cylindrical and the other being a surface of revolution that forms the recess wider at the opening than interiorly thereof.

Claim 17

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring-like blade housing adapted to be secured to a handle and to guide a continuous ring blade rotatable in the housing, said housing having two axial ends and an outer periphery, an arcuate recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, and having two spaced concentric arcuate wall surfaces engageable by the blade, one of said surfaces being cylindrical and the other being a surface of revolution that forms the recess wider at the opening than interiorly thereof.

Claim 18

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring-like blade housing adapted to be secured to a handle and to guide a continuous ring blade rotatable in the housing, said housing having an arcuate recess for receiving a toothed portion of the ring blade and from which a cutting portion of the blade extends, and having a peripheral wall that is frusto-conically arcuate with a minor radius at an axial end of the wall that is adjacent the toothed portion of the blade and a major radius adjacent the opposite axial end from which the cutting portion extends.

Claim 19

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring-like blade housing adapted to be secured to a handle and to guide a continuous ring blade rotatable in the housing, said housing having an arcuate recess for receiving a toothed portion of the ring blade and from which a cutting portion of the blade extends, and having a peripheral wall that is frusto-conically arcuate with a minor radius at an axial end of the wall that is adjacent the toothed portion of the blade and a major radius adjacent the opposite axial end from which the cutting portion extends.

Claim 20

A gear-driven ring blade for a hand knife of the type used for cutting meat and other suitable products, said blade comprising: a ring gear portion at one axial end of the blade and an outwardly flared thinner portion extending therefrom to the other axial end and terminating at the other axial end in a cutting edge, and an exterior peripheral flange at the juncture between the thicker and thinner portions, the ring gear portion having an inner and an outer peripheral surface and the flared thinner portion having an inner peripheral surface, all of said surfaces being different surfaces of revolution, said ring gear portion increasing in thickness axially and being thickest at said flange.

Claim 21

A gear-driven ring blade for a hand knife of the type used for cutting meat and other suitable products, said blade comprising: a ring gear portion at one axial end of the blade and an outwardly flared thinner portion extending therefrom to the other axial end and terminating at the other axial end in a cutting edge, and an exterior peripheral flange at the juncture between the thicker and thinner portions, the ring gear portion having an inner and an outer peripheral surface and the flared thinner portion having an inner peripheral surface, all of said surfaces being different surfaces of revolution, said ring gear portion increasing in thickness axially and being thickest at said flange.

Claim 22

A gear-driven ring blade for a hand knife of the type used for cutting meat and other suitable products, said blade comprising: a ring gear portion at one axial end of the blade and an outwardly flared thinner portion extending therefrom to the other axial end and terminating at the other axial end in a cutting edge, and an exterior peripheral flange at the juncture between the thicker and thinner portions, said flange being frusto-conical in shape, and the ring gear portion having an inner and an outer peripheral surface, one of which is cylindrical and the other of which is tapered.

Claim 23

A gear-driven ring blade for a hand knife of the type used for cutting meat and other suitable products, said blade comprising: a ring gear portion at one axial end of the blade and an outwardly flared thinner portion extending therefrom to the other axial end and terminating at the other axial end in a cutting edge, and an exterior peripheral flange at the juncture between the thicker and thinner portions, said flange being frusto-conical in shape, and the ring gear portion having an inner and an outer peripheral surface, one of which is cylindrical and the other of which is tapered.

Claim 24

A gear-driven ring blade for a hand knife of the type used for cutting meat and other suitable products, said blade comprising: a ring gear portion at one axial end of the blade and an outwardly flared thinner portion extending therefrom to the other axial end and terminating at the other axial end in a cutting edge, and an exterior peripheral flange at the juncture between the thicker and thinner portions, the ring gear portion having a cylindrical outer peripheral surface and a frusto-conical inner peripheral surface angled in an opposite direction from that of said flared thinner portion, said ring gear portion being thinnest at the said one axial end.

Claim 25

A gear-driven ring blade for a hand knife of the type used for cutting meat and other suitable products, said blade comprising: a ring gear portion at one axial end of the blade and an outwardly flared thinner portion extending therefrom to the other axial end and terminating at the other axial end in a cutting edge, and an exterior peripheral flange at the juncture between the thicker and thinner portions, the ring gear portion having a cylindrical outer peripheral surface and a frusto-conical inner peripheral surface angled in an opposite direction from that of said flared thinner portion, said ring gear portion being thinnest at the said one axial end.

Claim 26

A gear-driven ring blade as set forth in claim 13 wherein said exterior peripheral flange is radial.

Claim 27

A hand knife for cutting meat and other suitable products, comprising a handle; a ring-like blade housing at one end of the handle and having a central axis; a continuous ring blade rotatable in the housing about said axis; and means to retain the blade in the housing; said housing having two axial ends and an outer periphery, an arcuate recess for the blade opening toward one axial end of the housing, spaced inwardly of the outer periphery, and having two spaced concentric arcuate wall surfaces engageable by the blade, one of said surfaces being cylindrically arcuate in shape and the other being a surface of revolution that forms the recess wider at the opening than interiorly thereof; said handle having an arcuate face and a face transverse thereto for locating said housing relative to the handle; and said blade having gear teeth received in said recess and a cutting portion extending from the housing, the gear teeth having inner and outer peripheral surfaces that match in contour the facing wall surfaces of the housing that forms the recess.

Claim 28

A hand knife for cutting meat and other suitable products, comprising a handle; a ring-like blade housing at one end of the handle and having a central axis; a continuous ring blade rotatable in the housing about said axis; and means to retain the blade in the housing; said housing having two axial ends and an outer periphery, an arcuate recess for the blade opening toward one axial end of the housing, spaced inwardly of the outer periphery, and having two spaced concentric arcuate wall surfaces engageable by the blade, one of said surfaces being cylindrically arcuate in shape and the other being a surface of revolution that forms the recess wider at the opening than interiorly thereof; said handle having an arcuate face and a face transverse thereto for locating said housing relative to the handle; and said blade having gear teeth received in said recess and a cutting portion extending from the housing, the gear teeth having inner and outer peripheral surfaces that match in contour the facing wall surfaces of the housing that forms the recess.

Claim 29

A hand knife as set forth in claim 15 wherein said handle has an elongated grip portion and an end portion to which the housing is attached, said end portion including an elongated depression extending in the longitudinal direction of the grip portion and on one side only of an imaginary plane along the longitudinal centerline of the grip portion and containing said axis, said depression opening in directions axially and laterally of said housing and being of a size and shape to accommodate and locate a user's thumb when the grip portion is held in the user's hand.

Claim 30

A hand knife as set forth in claim 15 wherein the outer concentric arcuate wall surface is cylindrical and the inner is frusto-conical.

Claim 31

A hand knife for cutting meat and other suitable products, comprising a handle; a ring-like blade housing secured at one end of the handle; a continuous ring blade rotatable in the housing; and means to retain the blade in the housing; said housing having two axial ends and an outer periphery, an arcuate recess for the blade opening toward one axial end of the housing, spaced inwardly of the outer periphery, and having two spaced concentric arcuate wall surfaces engageable by the blade, one of said surfaces being cylindrically arcuate in shape and the other being a surface of revolution that forms the recess wider at the opening than interiorly thereof; and said blade having gear teeth received in said recess and a cutting portion extending from the housing, the gear teeth having inner and outer peripheral surfaces that match in contour the facing wall surfaces of the housing that form the recess.

Claim 32

A hand knife for cutting meat and other suitable products, comprising a handle; a ring-like blade housing secured at one end of the handle; a continuous ring blade rotatable in the housing; and means to retain the blade in the housing; said housing having two axial ends and an outer periphery, an arcuate recess for the blade opening toward one axial end of the housing, spaced inwardly of the outer periphery, and having two spaced concentric arcuate wall surfaces engageable by the blade, one of said surfaces being cylindrically arcuate in shape and the other being a surface of revolution that forms the recess wider at the opening than interiorly thereof; and said blade having gear teeth received in said recess and a cutting portion extending from the housing, the gear teeth having inner and outer peripheral surfaces that match in contour the facing wall surfaces of the housing that form the recess.

Claim 33

A hand knife for cutting meat and other suitable products, comprising a handle; a ring-like blade housing secured at one end of the handle; a continuous ring blade rotatable in the housing; and means to retain the blade in the housing; said housing having two axial ends and an outer periphery, an arcuate recess for the blade opening toward one axial end of the housing, spaced inwardly of the outer periphery, and having two spaced concentric arcuate wall surfaces engageable by the blade, an outer one of said surfaces being cylindrically arcuate in shape and an inner one being frusto-conically arcuate in shape, the space between the walls being greatest at said one axial end of the housing; and said blade having gear teeth received in said recess and a cutting portion extending from the housing, the gear teeth having inner and outer peripheral surfaces, the said outer peripheral surface being cylindrical and facing the said cylindrically arcuate wall surface and the inner peripheral surface being frusto-conical and facing the said frusto-conically arcuate wall surface.

Claim 34

A hand knife for cutting meat and other suitable products, comprising a handle; a ring-like blade housing secured at one end of the handle; a continuous ring blade rotatable in the housing; and means to retain the blade in the housing; said housing having two axial ends and an outer periphery, an arcuate recess for the blade opening toward one axial end of the housing, spaced inwardly of the outer periphery, and having two spaced concentric arcuate wall surfaces engageable by the blade, an outer one of said surfaces being cylindrically arcuate in shape and an inner one being frusto-conically arcuate in shape, the space between the walls being greatest at said one axial end of the housing; and said blade having gear teeth received in said recess and a cutting portion extending from the housing, the gear teeth having inner and outer peripheral surfaces, the said outer peripheral surface being cylindrical and facing the said cylindrically arcuate wall surface and the inner peripheral surface being frusto-conical and facing the said frusto-conically arcuate wall surface.

Claim 35

A hand piece for a knife for cutting meat and other suitable products, the hand piece being adapted to support a ring-like housing for a rotary ring blade, said hand piece having an elongated grip portion and an end portion adapted to support and locate said housing, said end portion including an arcuate face and an elongated depression extending in the longitudinal direction of the grip portion and laterally offset from an imaginary plane along the longitudinal centerline of the grip portion and containing the axis of curvature of said face, said depression opening in directions parallel to and transversely of said axis and being of a size and shape to accommodate and locate a user's thumb when the grip portion is held in the user's hand.

Claim 36

A hand piece for a knife for cutting meat and other suitable products, the hand piece being adapted to support a ring-like housing for a rotary ring blade, said hand piece having an elongated grip portion and an end portion adapted to support and locate said housing, said end portion including an arcuate face and an elongated depression extending in the longitudinal direction of the grip portion and laterally offset from an imaginary plane along the longitudinal centerline of the grip portion and containing the axis of curvature of said face, said depression opening in directions parallel to and transversely of said axis and being of a size and shape to accommodate and locate a user's thumb when the grip portion is held in the user's hand.

Claim 37

A ring-like blade housing and a continuous ring blade rotatable in the housing, for a hand knife used for cutting meat and other suitable products, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, and having outer and inner spaced concentric circular wall surfaces engageable by the blade and spaced apart farther at said one axial end of the housing than inwardly thereof to allow assembly of the blade with the housing from the said one axial end, one of the said wall surfaces being cylindrical and the other being a surface of revolution that forms the recess wider at the opening than interiorly thereof and said blade having a ring gear portion at one axial end of the blade and a thinner portion extending therefrom to the other axial end and terminating at the other axial end in a cutting edge, and an exterior peripheral flange at the juncture between the thicker and thinner portions, the thinner portion including a cylindrical inwardly facing intermediate surface portion adjacent the flange and an outwardly flared blade portion extending from the intermediate surface portion toward the cutting edge, the ring gear portion having inner and outer peripheral surfaces that match in contour the facing wall surfaces of the housing that form the recess, and wherein said housing has a beveled surface on its inside diameter adjacent the recess opening and the flared thinner portion of the blade is spaced axially from the beveled surface of the housing by the said cylindrical intermediate surface portion.

Claim 38

A ring-like blade housing and a continuous ring blade rotatable in the housing, for a hand knife used for cutting meat and other suitable products, said housing having two axial ends and an outer periphery, a circular recess that opens toward one axial end of the housing, spaced inwardly of the outer periphery, and having outer and inner spaced concentric circular wall surfaces engageable by the blade and spaced apart farther at said one axial end of the housing than inwardly thereof to allow assembly of the blade with the housing from the said one axial end, one of the said wall surfaces being cylindrical and the other being a surface of revolution that forms the recess wider at the opening than interiorly thereof and said blade having a ring gear portion at one axial end of the blade and a thinner portion extending therefrom to the other axial end and terminating at the other axial end in a cutting edge, and an exterior peripheral flange at the juncture between the thicker and thinner portions, the thinner portion including a cylindrical inwardly facing intermediate surface portion adjacent the flange and an outwardly flared blade portion extending from the intermediate surface portion toward the cutting edge, the ring gear portion having inner and outer peripheral surfaces that match in contour the facing wall surfaces of the housing that form the recess, and wherein said housing has a beveled surface on its inside diameter adjacent the recess opening and the flared thinner portion of the blade is spaced axially from the beveled surface of the housing by the said cylindrical intermediate surface portion.

Claim 39

For use in a hand knife of the type having a rotary ring blade with gear teeth at one axial end and a cutting edge at the opposite axial end for cutting meat and other suitable products, a ring blade housing to guide the blade having an axially elongated peripherally continuous portion adapted to be secured to a handle and a circumferential outer wall for at least partially encircling a gear tooth portion at one axial end of the balde, said outer wall having a surface facing inwardly to guide the blade about said gear tooth portion, said surface being a surface of revolution that has a large diameter at one axial end than at the other.

Claim 40

For use in a hand knife of the type having a rotary ring blade with gear teeth at one axial end and a cutting edge at the opposite axial end for cutting meat and other suitable products, a ring blade housing to guide the blade having an axially elongated peripherally continuous portion adapted to be secured to a handle and a circumferential outer wall for at least partially encircling a gear tooth portion at one axial end of the balde, said outer wall having a surface facing inwardly to guide the blade about said gear tooth portion, said surface being a surface of revolution that has a large diameter at one axial end than at the other.

Claim 41

A ring blade housing as set forth in claim 22 including an inturned blade-retaining flange at each axial end of said surface.

Claim 42

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring blade housing to guide the blade having an axially elongated peripherally continuous portion extending in one axial direction adapted to be secured to a handle and a circumferential outer wall for at least partially encircling the blade, said outer wall having a surface facing inwardly to guide the blade, said surface being a surface of revolution that tapers radially outward in the opposite axial direction from said one direction.

Claim 43

For use in a hand knife of the type having a rotary ring blade for cutting meat and other suitable products, a ring blade housing to guide the blade having an axially elongated peripherally continuous portion extending in one axial direction adapted to be secured to a handle and a circumferential outer wall for at least partially encircling the blade, said outer wall having a surface facing inwardly to guide the blade, said surface being a surface of revolution that tapers radially outward in the opposite axial direction from said one direction.

Claim 44

A ring-like blade housing adapted to be secured to a handle of a hand knife of the type having a rotary power-driven continuous ring blade for cutting meat and other suitable products, said housing having a recess wholly or partially circular for receiving and guiding a toothed axial end portion of the ring blade and from which a cutting portion of the blade extends, said recess formed at least in part by a circumferential wall that at least partially encircles the blade and has a continuous contour of gradually increasing diameter, beginning at an inner axial end of the recess.

Claim 45

A ring-like blade housing adapted to be secured to a handle of a hand knife of the type having a rotary power-driven continuous ring blade for cutting meat and other suitable products, said housing having a recess wholly or partially circular for receiving and guiding a toothed axial end portion of the ring blade and from which a cutting portion of the blade extends, said recess formed at least in part by a circumferential wall that at least partially encircles the blade and has a continuous contour of gradually increasing diameter, beginning at an inner axial end of the recess.

Claim 46

A housing as set forth in claim 25 wherein the wall terminates at an inturned flange where its diameter is largest.

Claim 47

A ring-like blade housing adapted to be secured to a handle of a hand knife of the type having a rotary power-driven continuous ring blade for cutting meat and other suitable products, said housing having a recess wholly or partially circular for receiving and guiding a toothed axial end portion of the ring blade and from which a cutting portion of the blade extends, said recess formed at least in part by a circumferential wall that is encircled by the blade and has a continuous contour of gradually decreasing diameter, beginning at an inner axial end of the recess.

Claim 48

A ring-like blade housing adapted to be secured to a handle of a hand knife of the type having a rotary power-driven continuous ring blade for cutting meat and other suitable products, said housing having a recess wholly or partially circular for receiving and guiding a toothed axial end portion of the ring blade and from which a cutting portion of the blade extends, said recess formed at least in part by a circumferential wall that is encircled by the blade and has a continuous contour of gradually decreasing diameter, beginning at an inner axial end of the recess.