US3858461A

US3858461A - Shaver inner cutter

Info

Publication number: US3858461A
Application number: US414175A
Authority: US
Inventors: Robert J Tolmie
Original assignee: Sperry Rand Corp
Current assignee: Remington Products Inc; Sperry Corp
Priority date: 1973-11-08
Filing date: 1973-11-08
Publication date: 1975-01-07
Anticipated expiration: 1992-01-07
Also published as: DE2452859C2; NL7414423A; JPS5078464A; NL184460C; CH578920A5; JPS5741266B2; FR2250587B1; GB1451728A; DE2452859A1; AU7402974A; ATA773474A; FR2250587A1; NL184460B; AT333620B; CA1016735A

Abstract

A landless inner cutter having a body portion which is made from a single piece of metallic material such as a strip of sheet metal. The inner cutter has a body portion including a pair of longitudinal flanges provided with ledges which support a plurality of parallel, arch-shaped, cutter tooth blade sections. The blade sections span the space between the flanges and are disposed normal to the same. In addition, the inner cutter includes a support which is also made of a single piece of sheet metal, to which the blade sections are individually secured so as to rigidly maintain the same parallel to one another. The method of forming the blade sections in a strip of sheet metal in order to form a landless inner cutter, includes the steps of removing material from the strip to provide the same with a first archlike edge which has a rise and a span; cutting a second archlike edge in the strip which is longitudinally displaced from the first edge such that the span of the second edge intersects the rise of the first edge; bending the resulting arch-shaped strip material or blade section, between the archlike edges out of and normal to the plane of the strip, so as to provide a normally disposed, arch-shaped blade section and to expose another first archlike edge in the plane of the strip; and, repeating the cutting and bending steps, as necessary, to provide a plurality of equidistantly-spaced, normally disposed, arch-shaped blade sections in the strip.

Description

United States Patent 1 Tolmie SHAVER INNER CUTTER Robert J. Tolmie, F airfield, Conn.

[73] Assignee: Sperry Rand Corporation,

Bridgeport, Conn.

[22] Filed: Nov. 8, 1973 [21] Appl. No.: 414,175

[75] Inventor:

Primary Examinerl-larrison L. Hinson Attorney, Agent, or Firm-Charles R. Miranda [57] ABSTRACT A landless inner cutter having a body portion which is 1 1 Jan.7, 1975 made from a single piece of metallic material such as a strip of sheet metal. The inner cutter has a body portion including a pair of longitudinal flanges provided with ledges which support a plurality of parallel, archshaped, cutter tooth blade sections. The blade sections span the space between the flanges and are disposed normal to the same. In addition, the inner cutter includes a support which is also made of a single piece of sheet metal, to which the blade: sections are individually secured so as to rigidly maintain the same parallel to one another. The method of forming the blade sections in a strip of sheet metal in order to form a landless inner cutter, includes the steps of removing material from the strip to provide the same with a first archlike edge which has a rise and a span; cutting a second archlike edge in the strip which is longitudinally displaced from the first edge such that the span of the second edge intersects the rise of the first edge; bending the resulting arch-shaped strip material or blade section, between the archlike edges out of and normal to theplane of the strip, so as to provide a normally disposed, arch-shaped blade section and to expose another first archlike edge in the plane of the strip; and, repeating the cutting and'bending steps, as necessary, to provide a plurality of equidistantlyspaced, normally disposed, arch-slnaped blade sections in the strip.

10 Claims, 12 Drawing Figures atented Jan. 7, 1975 5 Sheets-Sheet 1 Patented Jan. 7, 1975 5 Sheets-Sheet 2 N LVK at ented Jan. 7, 1975 5 Sheets-Sheet 5 SHAVER INNER CUTTER BACKGROUND OF THE INVENTION This invention is concerned with inner cutters for electric dry shavers, and more particularly with a land less inner cutter and a method of forming blade sections in a thin strip of metallic material so as to form a landless inner cutter.

Prior art inner cutters are sometimes made of lightweight sheet metal parts so as to reduce the mass of the inner cutter, which results in lessening the vibration engendered by the inner cutter as it is reciprocated relative to an outer cutter for shearing hair. The various prior art methods of fabricating such lightweight inner cutters have included the steps of forming a plurality of generally C-shaped, equidistantly longitudinally spaced cuts in a strip of sheet metal material, and bending the. material within the perimeters of the respective cuts out of the plane of the strip, so as to form a plurality of parallel, upstanding tabs and thus blade sections. In such processes a given blade section is separated from an adjacent blade section by a transversely-extending portion of strip material remaining in the plane of the strip, i.e., a supporting land, andby a space equivalent to the height of the blade section bent out of the plane of the strip. As a consequence, the number of blade sections of a particular height which can be formed, in a given length of strip material, depends on the width of the space occupied by the supporting lands between the various blade sections.

Although the blade sections have been more closely spaced adjacent to one another by eliminating the supporting lands between the blade sections, the prior art processes for doing so areexpensive and time consuming due to the necessity of reverting to processes which include the steps of cutting of the blade sections completely out of the strip of sheet metal, aligning them with one another and individually separately securing them to a supporting member or mount. In some instances the mount has consisted of a plurality of parallel rods which are passed through openings provided in the aligned blade sections and then secured to the blade sections, for example, as by welding. In other instances the mount has consisted of an elongated bar having equidistantly longitudinally-spaced, transverse cuts, within which the blade sections are individually mounted and secured in place by means of a suitable adhesive.

An object of this invention is to provide a novel landless inner cutter;

Another object is to provide a method of forming blade sections in a strip of metallic material for forming an inner cutter for a shaver, without forming lands between the blade sections;

A further object is to provide an inexpensive process for forming closely spaced blade sections in a strip of sheet metal material for forming a landless inner cutter for a shaver; and

A still furtherobject is to provide an improved inner cutter having a sheet metal body, including cutter tooth blade sections which are formed in a single piece of sheet metal material in a manner allowing for more closely spacing the blade sections than has heretofore been possible. r

SUMMARY OF THE INVENTION I comprises a body portion made from a strip of metallic material such as a piece of sheet metal. The body portion includesa pair of longitudinally-extending side sections and a plurality of transversely-extending, archshaped blade sections. The side sections each include a plurality of equidistantly longitudinally spaced ledges, each of which is disposed opposite to a ledge of the other side section and forms therewith a pair of ledges. As a consequence, the side sections, taken together, include a plurality of equidistantly longitudinally spaced pairs of ledges. The blade sections, which are each supported by a given pair of ledges, span the space between the side sections and extend normal to the same. In addition, each of the blade sections has inner and outer arch-shaped edges, and the opposite extremities of each blade section in conjunction with the side sections define spaced bends in the span of the outer archshaped edge of the respective blade sections. The inner cutter also includes means for securing the normally disposed blade sections parallel to one another.

The method of forming blade sections for the landless inner cutter includes the step of removing material from the strip so as to provide the same with a first transversely-extending archlike edge in the plane of the strip and between its side edges. The first archlike edge has a rise extending longitudinally of the strip and a span extending transversely of the strip. The strip is then provided with an archlike cut to form a second archlike edge in the strip which has a span that intersects the rise of the first archlike edge. The first and second edges form an arch-shaped blade section in the plane of the strip which is bent out of the plane of the strip and normal to the same. In doing so, another first archlike edge is exposed in the plane of the strip, i.e., the other edge formed by the archlike cut. By repeating the cutting and bending steps a plurality of normally disposed blade sections are formed in the strip.

BRIEF DESCRIPTION OF THE DRAWINGS As shown in the drawings, wherein like reference numerals designate like or corresponding parts throughout the several Figures:

FIG. 1 is a perspective view of a landless inner cutter for a shaver, the inner cutter including an elongated body portion having a pair of longitudinal side sections and a plurality of transverse blade sections, and includ ing a member for securing the blade sections parallel to one another;

FIG. 2 is a perspective view of the underside of a typical strip of sheet metal material prior to forming the blade sections in the strip so as to form the body portion of the inner cutter of FIG. 1;

FIG. 3 is a fragmentary cross-sectional view, in elevation, of the strip of material of FIG. 2, seated on a die beneath a lancing tool which is adaptedto cut and bend the strip material for the purpose of forming blade secshown in FIG. 3;

FIG. 5 is an enlarged, fragmentary plan view of the underside of the strip of material as it is shown in FIG. 3, with a dot-dashed area superimposed on the Figure for representing the area cut and bent out of the plane of the strip by the lancing tool of FIG. 3 during its first working cycle;

FIG. 6 is a section of the strip of material of FIG. 5, taken substantially along the line 6-6 of FIG. 5;

FIG. 7 is a view of the strip of material as it is shown in FIG. 5, after being cut and bent a second time, with a dot-dash area superimposed on the Figure for representing the area cut and bent out of the plane of the strip by the lancing tool of FIG. 3 during its second and subsequent working cycles;

FIG. 8 is a section of the strip of material of FIGS. 7 and/or 9, taken substantially along the line 88 of FIGS. 7 and/or 9;

FIG. 9 is a fragmentary bottom plan view of the strip of material of FIG. 7, after being repeatedly cut and bent by means of the lancing tool of FIG. 3;

FIG. 10 is an enlarged bottom plan view of the strip of material of FIG. 5, after being transversely severed at spaced intervals so as to provide a discrete length of strip material including a plurality blade sections;

FIG. 11 is a side view, in elevation, of the strip of material shown in FIG. 10; and

FIG. 12 is a side view, in elevation, of two alternative types of blade sections which may be formed in the strip of material of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a shaver inner cutter 10, according to the invention, generally includes a body portion 12 and a body supporting portion 14. The body portion 12 is an elongated part of the inner cutter 10 which includes a pair of straight, longitudinally-extending side sections 16 and a plurality of arch-shaped, transverselyextending blade sections 18.

For rigidity purposes, the side sections 16 (FIG. 1) are preferably elongated flanges having an inverted L- shaped, transverse cross-section. Each of the flanges 16 has a horizontally-extending base portion 20 and a vertically-extending leg portion 22, the latter including a longitudinally-extending edge 23. The base portions 20 respectively include a plurality of generally V- shaped ledges 24 located at equidistantly spaced longitudinal intervals. Each of the ledges 24 extends inwardly of the body portion 12 and towards a like ledge 24 of the opposite base portion 20 so as to define with the same a transversely spaced pair of ledges 24. Thus the side sections 16, considered together, include a plurality of equidistantly longitudinally spaced pairs of I ledges 24. Each pair of ledges 24 merges with and supports the extremities of a given arch-shaped blade section 18 and in conjunction with the same defines a pair of intersections in the form of spaced bends 25 in the plane of the base portions 20.

The blade sections 18 (FIG. 1) each have outer and inner arch-shaped peripheral edges, respectively designated 26 and 28. In FIG. 1 the outer peripheral edges 26 are suitably configured for slidably cooperating with a shaver outer cutter of the foil type (not shown). As a consequence, each of the outer peripheral edges 26 has a rise 30 and a span 32, and includes an arcuatelyshaped mid-portion 34 and a pair of straight portions 36. The straight portions 36 extend parallel to one another, from the extremities of the mid-portions 34 to the ledges 24, and extend parallel to the rise 30 of the blades outer edge 26. The arcuate-ly-shaped midportions 34, considered together, are particularly conformed to a radius of curvature corresponding to'that of are arcuately-shaped, longitudinally-extending segment of a cylinder (not shown). As shown in FIG. 1 the outer and inner

peripheral edges

26 and 28 are nonconcentric, although the inner edges 28 are substantially arcuately-shaped throughout their respective lengths. As a result, each of the blade sections 18 is wider at its mid-portion, as measured along the rise 30 of the outer peripheral edge 26, than it is at its extremities, as measured along the span 32 of the outer peripheral edge 26.

As shown in FIG. I, the bends 25 at the-extremities of a given blade section 18 are disposed in the span 32 of the outer peripheral edge 26 of the given blade section 18 and support the same normal to the plane of the base portions 20. Although the vertically-extending leg portions 22 of the side sections 16 also extend normal to the plane of the base portions 20, they do so in a direction which is opposite to that of the respective blade sections 18. As a consequence, when the inner cutter outer peripheral edges 26 are urged against a shaver outer cutter of the foil type (not shown) and the inner cutter 10 is reciprocated, the inner cutter leg portions 22 are not likely to contact the outer cutter foil (not shown) and damage the same.

The body supporting portion 14 is principally provided for rigidly maintaining the otherwise relatively weakly supported blade sections 18 parallel to one another. Although the body supporting portion 14 may take other suitable forms, it is shown in FIG. 1 as an elongated strip of metallic material which is substantially U-shaped in transverse cross-section. The body supporting portion 14 is disposed within the rise (not numbered) of the arch-shaped blade sections 18 and includes a pair of diverging side walls 38 joined to one another by a base wall 39. The side walls 38 respectively include a plurality of equidistantly longitudinally spaced slots 40 dimensioned to receive the blade sections 18. Each of the slots 40 is aligned with a slot 40 in the opposite side wall 38 so as to define with the same a pair of aligned slots 40. The adjacent pairs of slots 40 are spaced from one another a distance corresponding to the equidistant spacing between adjacent blade sections 18, so as to position the connected blade sections 18 parallel to one another. The body portion 12 is fixedly secured to the body supporting portion 14, for example, as by individually welding each of the blade sections 18 to the diverging side walls 38, so as to rigidly maintain the blade section 18 parallel to one another. According to the invention, the body supporting portion 14 is also provided with a pair of suitably longitudinally spaced depending tabs 42, one of which is shown in FIG. 1, which adapt the'body supporting portion 14, and thus the inner cutter 10, to be driven in a reciprocating path of travel by an electric shaver motor (not shown).

The above described body portion 12 (FIG. 1), and particularly the blade sections 18 of the same may be formed from a strip of sheet metal material 44 as shown in FIG. 2. Leg portions 22 (FIG. 2) corresponding to those shown in FIG. 1 may be formed in the strip 44 (FIG. 2) as by longitudinally bending marginal portions 22 of the strip 44 out of the plane of the strip 44 and normal to the same. Since the leg portions 22 are shown extending upwardly in FIG. 2, rather than downwardly as in FIG; 1, the upper side of the strip 44 of 7 FIG. 2 corresponds to the underside of the inner cutter body portion 12 of FIG. 1, before forming the blade sections 18.

The method of forming blade sections 118 (FIG. 1) in the strip 44 (FIG. 2) includes the steps of cutting and bending the strip 44. This may be done, as shown in FIG. 3, by means of a tool 45 and die 46. The die 46 acts as a platform upon which the strip 44 is disposed for incremental movement in the direction of its length, and has a pair of intersecting horizontally and vertically extending channels, respectively designated 47 and 48. The die 46 also includes a reciprocating die insert 49 which is adapted to move into and out of the die channel 47,.at the intersection of the two channels 47 and 48, in a path of travel perpendicular to the plane of the paper. In FIG. 3, the die insert 49 is shown retracted from channel 47. The tool 45, which is a suitably dimensioned reciprocating lancing tool, is adapted by well-known means to be moved into and out of the die channel 48 for repeatedly lancing the strip 44. The tool 45 (FIGS. 3 and 4) has an upper, horizontally-' extending surface 50; a vertically-extending, archshaped surface 51; a vertically-extending, flat surface 52; and a lower, horizontally-extending, rearwardly slanted, cutting and bending surface 54. Due to surface 54 being slanted, surfaceSl and 52 respectively form, in conjunction with the slanted surface 54, a leading arch-shaped edge 56 and a trailing straight edge 57. As shown in FIG. 4, the leading and trailing

edges

56 and 57 are disposed in the plane of the slanted surface 54. The leading arch-shaped edge 56 has a rise 58 and a span 59, the latter being coincident with the trailing edge 57. In addition, the leading edge 56 includes an arcuately-shaped mid-portion 60 and spaced, parallel extremities 63, the latter extending parallel to the rise 58 of the leading edge 56.

Before forming the blade sections 18 (FIG. 1) by means of the tool 45 and die 46 of FIG. 3, the movements of the strip 44, die insert 49 and lancing tool 45 must of course be synchronized by well-known means. A typical repeatable operating cycle may include, for example in the sequence set forth, the steps of incrementally advancing the strip 44 to the left, in the direction of the arrow (not numbered); moving the die insert 49 into the die channel 47; lowering the lancing tool 45 against and through the strip 44, so as to cut and bend out of the plane of the strip 44 a depending tab 64; further lowering the lancing tool 45, into the die channel 48, so as to bend the tab 64 against the die insert 49; moving the die insert 49 out of channel 47; and raising the lancing tool 45.

In the course of initially cutting and bending the strip 44 (FIG. 3), the tools leading arch-shaped edge 56 (FIG. 4) gradually forms, as is shown in FIG. 5, an archlike cut 68 and then an intersection 69 in strip 44. The cut 68 and intersection 69 are respectively substantially coextensive in length with the tools archshaped, leading edge 56 (FIG. 4) and straight, trailing edge 57. For discussion purposes, the strip area within the arch of the archlike cut 68 of FIG. 5, i.e., the area bounded by the cut 68 and intersection 69, is shown by means of a series of dot-dash lines and designated by the reference character A-l. As shown in FIGS. 4 and 5, since the dot-dash area A-l is substantially coextensive with the area of the strip 44 which is contacted by the lancing tools slanted surface 5-4; as the archlike cut 68 is being gradually formed, the tools slanted surface 54 gradually bends the dot-dash area A-1 out of the plane of the strip'44. The aforesaid! cutting and bending action proceeds until the tools trailing straight edge 57 bears against and further bends the dot-dash area A-I against the die insert 49 (FIG. 3) and normal to the plane of the strip 44 so as to form the depending tab 64 (FIG. 6). As shown in FIG. 5 an elongated intersection 69, in the form of a single transversely extending bend is thus formed in the plane of the strip 44.

As the dot-dash area A-l of FIG. 5 is gradually being bent out of the plane of the strip 44, a transverselyextending archlike edge 70 is gradually exposed in the plane of the strip 44, between the leg portions 22. The archlike edge 70 has an arcuately-shaped mid-portion 28 and oppositely spaced, parallel side portions 74, the latter extending from the extremities of the mid-portion 28 and longitudinally of the strip 44. The side portions 74 also extend parallel to the rise 30 of the archlike edge 70, the span 32 of which extends transversely of 1 the strip 44 and is substantially coincident and coextensive in length with the intersection 69.

As shown in FIG. 5, the rise 30, span 32, midportion 28, and side portions 74 of the archlike edge 70 are substantially coextensive in length, respectively, with the rise 58 (FIG. 4), span 57, midportion 60 and side portions 63 of the lancing tools leading archshaped edge 56, since the lancing tools leading archshaped edge 56 forms the archlike edge 70. Of course, since the lancing tools leading arch-shaped edge 56 also forms the outer periphery of the tab 64 (FIG. 6), the tab 64 includes an outer peripheral archlike edge 26, having a rise 30, span 32, mid-portion 34 and side portions 36, the lengthwise dimensions of which substantially correspond to those of the edge 70 of FIG. 5.

After initially cutting and bending the strip 44 (FIG. 5) and thus forming the first archlike edge 70 in the plane of the strip 44, the strip 44 is displaced a predetermined distance to the left as shown in FIG. 3, and thus advanced toward the lower edge of the paper as shown in FIG. 7. Thereafter, a second archlike cut 68A (FIG. 7) is gradually formed in the strip 44.-The archlike cut 68A is in all respects the same as the first archlike cut 68, but the predetermined distance through which the strip 44 is advanced is less than the length of the rise 30 of the first archlike cut 68. As a result, the aforesaid predetermined distance is less than the length of the rise 58 (FIG. 4) of the lancing tools leading arch-shaped edge 56, and, as shown in FIG. 7, the strip area A-2 within the arch of the second archlike cut 68A is smaller than the area of the lancing tools slanted surface 54 (FIG. 4). Accordingly, as the second archlike cut 68A is being gradually formed, the tools slanted surface 54 (FIG. 4) gradually bends the smaller dotdashed area A-2 (FIG. 7) out of the plane of the strip 44. Further, when the tools trailing straight edge 57 bears against and bends the smaller dot-dashed area A-2 it forms a pair of spaced intersections 25 in the form of spaced bends in the plane of the strip 44, rather than the single intersection 69 of FIG. 5; and, as shown in FIG. 8, forms the depending blade section 18, rather than the tab 64 of FIG. 6. Of course, as the dot-dash area A-2 of FIG. 7 is being gradually cut and bent out of the plane of the strip 44, the blade section 18 (FIGS. 7 and 8) is provided with an outer archlike peripheral edge 26 having a rise 30A and a span 32A; and, as shown in FIG. 7, another transversely-extending archlike edge 70A is gradually formed and exposed in the plane of the strip 44.

The span 32A of both of the newly formed archlike edges 26 and 70A are shown in FIG. 7 to be substantially coincident with one another and with the spaced intersections 25. Due to the strip 44 being advanced a distance which is less than the length of the rise 30 of the first archlike edge 70, the span 32A of the next adjacent or second archlike edge 26 intersects the rise 30 of the first archlike edge 70. It should be noted that although the archlike edge 26 is bent out of the strip 44, it is formed while it is in the plane of the strip 44. By the same token, although the dot-dash area A-2 of FIG. 7'is bent out of the plane of the strip 44, the first and second archlike edges, 70 and 26, form the blade section 18 in the plane of the strip 44. In addition, it should be noted that the dot-dash area A-2 (FIG. 7) is bent out of and normal to the plane of the strip 44 along the span 32A of the second archlike edge 26. The side portions 74, and a part 76 of each of the extremities of the mid-portion 28 of the first archlike edge 70, remain in the plane of the strip 44. As a consequence, substantially the entire second archlike edge 26, but less than all of the mid-portion 28 of the first archlike edge 70 respectively define, as is shown in FIG. 8, the outer and inner

peripheral edges

26 and 28 of the normally disposed blade section 18. On the other hand, the strip material remaining in the plane of the strip 44 (FIG. 7), including the edge portions 74, edge parts 76, and spaced intersections 25, define a pair of oppositely spaced ledges 24 in the plane of the strip 44. The ledges 24 merge with the blade section 18 of FIG. 8 and support the same normal to the plane of the strip 44.

Subsequent blade sections 18 (FIG. 9) are formed in the strip 44 in the same manner as hereinbefore described. For example, as shown in FIGS. 8 and 9,, the strip 44 is longitudinally displaced a distance of less than the length of the rise 30A of the previously formed archlike edge 70A so that the respective spans 32B of next formed archlike edges, 26 and 70B, intersect the rise 30A of the previously formed archlike edges, 26 and 70A; and, the strip 44 is cut and bent so as to provide another arch-shaped blade section 18 and a pair of spaced protrusions 25 which are in all respects the same as the previously formed blade sections 18 and protrusions 25.

As shown in FIG. 9, in the course of forming a plurality of

parallel blade sections

18, 18 and so on to 18" in the strip 44; a pair of oppositely disposed, longitudinally-extending base portions 20, respectively including a plurality of equi'distantly longitudinally spaced

protrusions

25, 25 and so on to 25", are formed in the plane of the strip 44. As shown in FIG. 9, the opposed base portions 20 are respectively joined to the leg portion 22 adjacent to the same to form a pair of parallel, longitudinally-extending side sections or flanges 16, which are L-shaped in transverse cross-section.

The aforesaid cutting and bending steps are repeated until a sufficient number of blade sections 18" are provided to form one or more inner cutter body portions 12 as shown in FIG. 1. Since this entails removing the tab 64 of FIG. 6 and providing a discrete length of strip material having a predetermined number of blade sections 18'', for example, the 21 blade sections, 18 to 18 shown in FIG. the tab 64 of FIG. 6 may be removed at any time after it is formed, whereas the process of cutting and bending is continued until at least the aforesaid predetermined number of blade sections 18" is formed in the strip.

Assuming at least 2l blade sections, 18 to 18 are formed in the strip 44 of FIG. 9; the inner cutter body portion 12 of FIG. 10 may be formed by transversely severing the strip 44 of FIG. 9 at longitudinally-spaced intervals, for example in a plane which is disposed parallel to and between the tab 64 and blade section 18 and which extends through the leg portions 22, and in a like plane disposed between the 21st sections 18 .and 22nd blade section (not shown).

Of course, it should be appreciated that the first archlike edge (FIG. 5) may be formed in the plane of the strip 44 by removing material from the latter by wellknown means other than as by cutting and bending the strip 44 as hereinbefore described. For example, the first archlike edge 70 may be formed in the strip 44 as by grinding the free end of the strip 44; in which case the tab 64 (FIG. 6) will not be formed in the strip 44. In the latter event the strip 44 of FIG. 9 need only be severed but once, i.e., between the blade sections 18 and 18 (not shown), to form the inner cutter body portions 12 (FIGS. 1 and 10). On the other hand, assuming the tab 64 of FIG. 6 is provided, and the strip 44 is just long enough to form only a single inner cutter body portion 12 (FIG. 10), again, the strip 44 need only be severed but once, i.e., to remove the tab 64 (FIG. 6), in order to form the inner cutter body portion 12 (FIGS. 1 and 10). Still further, if both .of the foregoing events occur the strip 44 need not be transversely severed at all to form a suitable inner cutter body portion 12.

In the process of forming the inner cutter body portion 12 the

blade sections

18 and 18 are aligned parallel to one another as shown in FIG. 11. At this juncture, in order to rigidly support the same, the blade sections 18 to 18 are normally individually fixedly secured to the body supporting portion 14 (FIG. 1), as by welding. Thereafter (FIG. 11) material is removed from theouter peripheral edges 26 to 26 of the respective blade sections 18 to 18 for example, as by grinding the same, so as to conform the respective edges, 26 to 26 to a desired contour, for example, that of an arcuately-shaped longitudinally extending segment of a cylinder (not shown). Of course, it is well within the scope of the invention that the step of removing material from the outer peripheral edges 26 to 26 preceed the steps of connecting the body supporting portion 14 (FIG. 1) to the blade sections 18 to 18 (FIG. 11), and/or that the latter be secured parallel to one another by other well-known means during the removing step.

The above described method of forming blade sections 18" (FIG. 8) in a strip of metallic material has been described in connection with forming archshaped blade sections 18" which are substantially arcuate in appearance. Of course, by changing the configuration of the tools surfaces 51, 52 and 54, and thus the

edges

56 and 57, it is well within the scope of the invention to provide other configurations of arch-shaped blade sections 18", for example, as shown in FIG. 12, those having the appearance of the blade sections 18(a) or 18(b).

In accordance with the objects of the invention there has been described an improved light-weight, landless inner cutter, including blade sections which are formed 9. from a single piece of sheet metal material; and an inexpensive process of forming the blade sections which allows for more closely spacing the blade sections than has heretofore been possible.

Inasmuch as certain changes may be made in the above described invention without departing from the spirit and scope of the same, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted in an illustrative rather than limiting sense. And, it isintended that the following claims be interpreted to cover all the generic and specific features of the invention herein described.

What is claimed is:

1. A method of forming blade sections in an elon gated thin strip of metallic material having longitudinally extending side edges, for forming a landless inner cutter to be used in an electric shaver, the steps comprising:

a. removing material from the strip to provide the strip with a first transversely extending archlike edge in the plane of the strip and between the side edges thereof, the first archlike edge being a reference edge having a rise extending longitudinally of the strip and having a span extending transversely of the strip;

b. cutting the strip at a place thereon which is longitudinally displaced from the first archlike edge so as to form a second archlike edge in the plane of the strip, the second archlike edge having a span which intersects the rise of the first archlike edge, the first and second archlike edges forming an arch-shaped blade section in the plane of the strip; bending the blade section along the span of the archlike edge so as to move the blade section out of the plane of the strip and substantially normal thereto, thereby exposing another archlike reference edge formed by said archlike cut in the plane of the strip, said first and second archlike edges respectively including the inner and outer peripheral edges of the normally disposed blade section, and said another archlike edge being a new first archlike reference edge in the plane of the strip; and

d. repeating the cutting and bending steps so as to form a plurality of blade sections disposed normal to the plane of the strip.

2. The method according to claim 1, wherein said removing step includes the step of cutting the strip so as to provide the strip with said first archlike edge and severing the strip along the span of said first archlike edge so as to remove a portion of the strip.

3. The method according to claim 1, wherein the steps-of cutting and bending a given blade section are effected by means of a lancing tool and performed in the course of one continuous relative movement of the tool and strip.

4. The method according to claim 1, wherein thestep of bending a given blade section includes the step of forming a pair of intersections in the strip which are disposed in the span of the second archlike edge of said given blade section, said intersections supporting the normally disposed given blade section at the extremities thereof.

5. The method according to claim 1, including the step of removing material-from the outer peripheral edges of said plurality of normally disposed blade sections so as to conform said outer edges to a desired contour.

6. The method according to claim 1, including the step of supporting said plurality of blade sections-to remove material from the outer peripheral edges thereof so as to conform said outer edges to a desired contour.

7. The method according to claim 1, including the step of transversely severing the strip at longitudinally spaced intervals so as to provide a strip portion having a predetermined number of blade sections.

8. The method according to claim 1, including the step of initially longitudinally bending marginal portions of the strip out of the plane of the strip and normal thereto so as to provide said strip with a pair of transversely spaced longitudinall y-extending flanges respectively having a base portion in the plane of the strip and a leg portion normal to the plane of the strip, whereby said plurality of blade sections are formed between said leg portions so as to extend normally from the base portions in a direction which is opposite to that of the leg portions, said base portions supporting the extremities of each of said blade sections.

9. The method according to claim 1, wherein each of said cutting steps includes forming archlike edges respectively having an arcuately-shaped mid-portion and parallel spaced side portions with the side portions extending from the extremities of the mid-portion and longitudinally of the strip, whereby the span of a given archlike edge in the plane of the strip extends between the extremities thereof and thus between the extremities of the spaced side portions of said given edge.

10. The method according to claim 9, including the step of removing material from the: mid-portions of the outer peripheral edges of said normally disposed blade sections so as to conform said mid-portions to the curvature of an arcuately-shaped longitudinally extending segment of a cylinder.

Claims

1. A method of forming blade sections in an elongated thin strip of metallic material having longitudinally extending side edges, for forming a landless inner cutter to be used in an electric shaver, the steps comprising: a. removing material from the strip to provide the strip with a first transversely extending archlike edge in the plane of the strip and between the side edges thereof, the first archlike edge being a reference edge having a rise extending longitudinally of the strip and having a span extending transversely of the strip; b. cutting the strip at a place thereon which is longitudinally displaced from the first archlike edge so as to form a second archlike edge in the plane of the strip, the second archlike edge having a span which intersects the rise of the first archlike edge, the first and second archlike edges forming an arch-shaped blade section in the plane of the strip; c. bending the blade section along the span of the archlike edge so as to move the blade section out of the plane of the strip and substantially normal thereto, thereby exposing another archlike reference edge formed by said archlike cut in the plane of the strip, said fiRst and second archlike edges respectively including the inner and outer peripheral edges of the normally disposed blade section, and said another archlike edge being a new first archlike reference edge in the plane of the strip; and d. repeating the cutting and bending steps so as to form a plurality of blade sections disposed normal to the plane of the strip.

3. The method according to claim 1, wherein the steps of cutting and bending a given blade section are effected by means of a lancing tool and performed in the course of one continuous relative movement of the tool and strip.

4. The method according to claim 1, wherein the step of bending a given blade section includes the step of forming a pair of intersections in the strip which are disposed in the span of the second archlike edge of said given blade section, said intersections supporting the normally disposed given blade section at the extremities thereof.

5. The method according to claim 1, including the step of removing material from the outer peripheral edges of said plurality of normally disposed blade sections so as to conform said outer edges to a desired contour.

6. The method according to claim 1, including the step of supporting said plurality of blade sections to remove material from the outer peripheral edges thereof so as to conform said outer edges to a desired contour.

8. The method according to claim 1, including the step of initially longitudinally bending marginal portions of the strip out of the plane of the strip and normal thereto so as to provide said strip with a pair of transversely spaced longitudinally-extending flanges respectively having a base portion in the plane of the strip and a leg portion normal to the plane of the strip, whereby said plurality of blade sections are formed between said leg portions so as to extend normally from the base portions in a direction which is opposite to that of the leg portions, said base portions supporting the extremities of each of said blade sections.

10. The method according to claim 9, including the step of removing material from the mid-portions of the outer peripheral edges of said normally disposed blade sections so as to conform said mid-portions to the curvature of an arcuately-shaped longitudinally extending segment of a cylinder.