US 12,296,496 B2
Method of manufacturing a hair cutter
Andreas Erndt, Kelkheim (DE); Thorsten Piesker, Friedrichsdorf (DE); Wolfgang Stegmann, Moerfelden (DE); and Bernhard Sikora, Kelkheim (DE)
Assigned to Braun GMBH, Kronberg (DE)
Filed by Braun GmbH, Kronberg (DE)
Filed on May 19, 2023, as Appl. No. 18/199,395.
Prior Publication US 2023/0373115 A1, Nov. 23, 2023
Int. Cl. B26B 19/38 (2006.01); B21D 26/033 (2011.01)
CPC B26B 19/3893 (2013.01) [B21D 26/033 (2013.01)] 17 Claims
OG exemplary drawing
 
1. Method of manufacturing a hair cutter with an outer metal shell, comprising the steps of
forming the outer metal shell into one integral piece with a homogenous, seamless structure and a hollow, elongated, closed-ring or closed-sleeve shape,
wherein said forming step includes positioning a hollow, metal shell blank in a cavity of a mold surrounding an outer side of said metal shell blank, wherein a hydraulic pressure is applied to an inner side of the hollow metal shell blank, thereby expanding the hollow metal shell blank and pressing the metal shell blank, with an outer side, against the contour of the cavity of the mold so the outer side of the metal shell blank adopts the contour of the mold,
creating frontal openings at opposite axial end portions,
mounting functional components and/or modules for performing or helping to perform a personal care function into and/or onto said formed outer metal shell, and wherein the outer metal shell is formed with an intermediate section between the opposite end portions, the intermediate section including at least two lateral openings and/or lateral perforations for accessing or connecting with the functional components, the at least two lateral openings being formed after the hydraulic pressure is applied to expand the hollow metal shell blank and being open in a direction transverse to the frontal openings.
 
16. Method of manufacturing a hair cutter with an outer metal shell, comprising the steps of forming the outer metal shell into one integral piece with a homogenous, seamless structure and a hollow, elongated, closed-ring or closed-sleeve shape, wherein said forming step includes positioning a hollow, metal shell blank in a cavity of a mold surrounding an outer side of said metal shell blank, wherein a hydraulic pressure is applied to an inner side of the hollow metal shell blank, thereby expanding the hollow metal shell blank and pressing the metal shell blank, with an outer side, against the contour of the cavity of the mold so the outer side of the metal shell blank adopts the contour of the mold, creating frontal openings at opposite axial end portions and at least one lateral opening or perforation at an intermediate side portion at the formed outer metal shell, mounting functional components and/or modules for performing or helping to perform a personal care function into and/or onto said formed outer metal shell, and wherein at least one functional component or module projects partly inside and partly outside the formed metal shell, the at least one lateral opening being formed after the hydraulic pressure is applied to expand the hollow metal shell blank and being open in a direction transverse to the front openings.
 
17. Method of manufacturing a hair cutter with an outer metal shell, comprising the steps of
forming the outer metal shell into one integral piece with a homogenous, seamless structure and a hollow, elongated, closed-ring or closed-sleeve shape,
wherein said forming step includes positioning a hollow, metal shell blank in a cavity of a mold surrounding an outer side of said metal shell blank, wherein a hydraulic pressure is applied to an inner side of the hollow metal shell blank, thereby expanding the hollow metal shell blank and pressing the metal shell blank, with an outer side, against the contour of the cavity of the mold so the outer side of the metal shell blank adopts the contour of the mold,
creating frontal openings at opposite axial end portions,
mounting functional components and/or modules for performing or helping to perform a personal care function into and/or onto said formed outer metal shell, and wherein said outer metal shell is formed with an intermediate section between the opposite end portions, the intermediate section including at least two lateral openings, the functional components and/or modules comprise front and back modules which extend at least partly through two of the lateral openings, the at least two lateral openings being formed after the hydraulic pressure is applied to expand the hollow metal shell blank and being open in a direction transverse to the frontal openings.