Shaving apparatus

Abstract: A shaving apparatus has at least one shaving unit (2) which comprises an external shaving member ( 3 ) and an internal shaving member ( 4 ) which is rotatable relative to the external shaving member, the external shaving member having an annular wall portion (5) with lamellae (7) which extend in substantially radial directions and between which hair-entry apertures (8) are formed, the internal shaving member comprising cutters (10) which describe a path adjoining the inner side (12) of the annular wall portion (5) of the external shaving member ( 4 ). In order to obtain a closer shave without an increased risk of injury to the skin the shaving apparatus is characterized in that the cutters (10) together form one undulating continuous ring-shaped cutter body covering all the hair-entry apertures (8).

Description: The invention relates to a shaving apparatus having at last one shaving unit comprising an external shaving member and an internal shaving member which is rotatable relative to the external shaving member, the external shaving member having an annular wall portion with lamellae which extend in substantially radial directions and between which hair-entry apertures are formed, the internal shaving member comprising cutters having cutting edges which describe a path adjoining the inner side of the annular wall portion of the external shaving member. Such a shaving apparatus is known from US-A-5,031,315 (PHN 12794) . In this known shaving apparatus the part of each cutter which is in contact with the inner side of the annular wall portion of the external shaving member is generally of rectangular cross-section, the large rectangle sides being directed substantially radially. The foremost vertices of the rectangle, viewed in the direction of rotation, are more likely to cause injury to the skin protruding from a hair-entry aperture than the central portion of the cutter. For this reason the thickness of the lamella should be larger at the location of the ends of the cutter than at the location of the centre of the cutter. This leads to a shave which is less close than desired. It is an object of the invention to improve the shaving apparatus in such a manner that a close shave is obtained within a shorter time and without the risk of injury to the skin being increased. To this end the shaving apparatus according to the preamble of claim 1, in accordance with the invention, is characterized in that the cutters together form one undulating continuous ring-shaped cutter body, that the cutting edges are located at the axial end of the ring-shaped cutter body and that the cutting edges together also have a continuous undulating shape. An advantage of the shaving apparatus in accordance with the invention is that the cutters no longer have vertices which can injure the skin, so that the thickness of the lamellae near the radial ends of the cutters can be reduced, which yields a closer shave. An additional advantage is that the likelihood of lamella breakage is reduced. It is to be noted that DE-A-1816867 discloses a shaving apparatus having undulating and ring-shaped cutters. However, the external shaving member of this known apparatus is formed by a cylindrical semicircular foil, whereas the internal shaving member is a shaving cylinder comprising a plurality of cutter discs which extend perpendicularly to the axis of rotation of the shaving cylinder and whose undulating cutters are curved in conformity with the cylindrical semicircular foil. A preferred embodiment of the shaving apparatus is characterized in that the cutters extend substantially perpendicularly to the path of the cutting edges. It has been found that the angle of the cutters relative to the path of the cutting edges influences the degree of skin irritation. An acute angle between the cutter and the external shaving member is more likely to lead to skin injury than a right angle, while it has been found that a right angle yet provides a satisfactory shaving performance. It is now even possible to reduce the lamella thickness. The invention will now be described in more detail on the basis of an exemplary embodiment shown in the drawings. In the drawings: Fig. 1 is a perspective view of a shaving apparatus comprising three shaving units, Fig. 2 is an enlarged-scale perspective view of an external shaving member and an internal shaving member used in the shaving unit shown in Fig. 1, Fig. 3 is a cross-sectional view of a shaving unit shown in Fig. 1, and Fig. 4 shows diagrammatically a shaving unit whose cutter has a slightly different undulation. The shaving apparatus comprises a housing 1 with three shaving units 2. A shaving unit 2 comprises an external shaving member 3 and an internal shaving member 4 , which is rotatable relative to the external shaving member. In known manner the internal shaving member can be driven by means of an electric motor, not shown, which is accommodated in the housing. The external shaving member 3 has a substantially annular wall portion 5. The inner side of the external shaving member has an annular groove 6 (see Fig. 3) at the location of the wall portion 5. The wall portion 5 is constituted by lamellae 7 which extend in substantially radial directions and between which hair-entry apertures 8 are formed. The internal shaving member 4 comprises a support 9 carrying a cutter 10. The cutter comprises a cylindrical wall portion having a continuous undulating shape corresponding to a circle. At an axial end the undulating wall portion has a large number of cutting edges 11, which together also have a continuous undulating shape and which describe a path adjoining the bottom 12 of the groove 6 in the external shaving member 3 , which groove is formed by the lamellae 7. The internal shaving member 4 can be driven by an electric motor about an axis of rotation 13, which axis extends perpendicularly to the wall portion 5 of the external shaving member 3 formed with the hair-entry apertures 8. Fig. 4 shows diagrammatically a shaving unit 2 whose cutter 10 has a slightly different undulating shape. This cutter has 90 undulations and, consequently, 90 cutting edges 11.

Claims: A shaving apparatus having at least one shaving unit (2) comprising an external shaving member (3) and an internal shaving member (4) which is rotatable relative to the external shaving member (3), the external shaving member (3) having an annular wall portion (5) with lamellae (7) which extend in substantially radial directions and between which hair-entry apertures (8) are formed, the internal shaving member (4) comprising cutters having cutting edges (11) which describe a path adjoining the inner side of the annular wall portion (5) of the external shaving member (3), characterized in that the cutters together form one undulating continuous ring-shaped cutter body (10), that the cutting edges (11) are located at the axial end of the ring-shaped cutter body (10) and that the cutting edges (11) together also have a continuous undulating shape. A shaving apparatus as claimed in Claim 1, characterized in that the cutters extend substantially perpendicularly to the path of the cutting edges (11).

Inventors: DEKKER JACOBUS NICOLAAS, WEVERS DIRK HENDRIK, DEKKER, JACOBUS NICOLAAS, WEVERS, DIRK HENDRIK
Applicants: PHILIPS ELECTRONICS NV, PHILIPS ELECTRONICS N.V.
Application year: 1993
Main classification: B26B19
IPC codes: B26B19