SHAVING HEAD WITH JOINTLY DRIVABLE CUTTING MEMBER AND HAIR MANIPULATOR

Abstract: The invention relates to a shaving head (5) which comprises a cutting member (17) having a cutting edge (19) for cutting hairs (53) growing from human skin (51). The shaving head (5) also comprises a hair manipulator (21) which is arranged in front of the cutting edge, viewed in a shaving direction (Y) of the shaving head. The hair manipulator can be driven in a direction parallel to the cutting edge to move the hairs in a direction substantially parallel to the cutting edge, and protects the skin against incised wounds and irritations. According to the invention, the hair manipulator is arranged in a fixed position with respect to the cutting member, the hair manipulator and the cutting member being jointly drivable in a direction parallel to the cutting edge. In this manner, an accurately defined position of the hair manipulator relative to the cutting member, which is necessary for a safe operation of the shaving head, can be obtained in a simple and reliable manner without the use of an accurate construction of the shaving head. The shaving head is used in a shaver (1) according to the invention, which further comprises driving means (43) for driving the shaving head.

Description: Shaving head with jointly drivable cutting member and hair manipulator. The invention relates to a shaving head provided with a cutting member having a cutting edge for cutting hairs growing from skin, and with a hair manipulator which, viewed in a displacement direction of the shaving head, is arranged in front of the cutting edge and which is drivable in a direction substantially parallel to the cutting edge for moving the hairs in a direction substantially parallel to the cutting edge. The invention also relates to a shaver comprising a shaving head and a drive mechanism for driving the shaving head, which shaving head is provided with a cutting member having a cutting edge for cutting hairs growing from skin, and with a hair manipulator which, viewed in a displacement direction of the shaving head, is arranged in front of the cutting edge and which is drivable, by means of the drive mechanism, in a direction substantially parallel to the cutting edge for moving the hairs in a direction substantially parallel to the cutting edge. A shaving head and a shaver of the types mentioned in the opening paragraphs are known from EP-A-0 855 256. The cutting member of the known shaving head and the known shaver is arranged in a fixed position in the shaving head. The hair manipulator comprises a comb which is arranged parallel to the cutting edge and which comprises teeth extending substantially perpendicularly to the cutting edge. By means of the drive mechanism, reciprocating movements of the hair manipulator with respect to the cutting member are generated, in operation, in a direction parallel to the cutting edge. When a user moves the shaving head over the skin in the displacement direction, the hairs are first caught between the teeth of the hair manipulator. The teeth are arranged at a relatively small distance from each other, so that reciprocating movements of the hairs in a direction substantially parallel to the cutting edge are generated by means of the hair manipulator and, during cutting, the hairs are reciprocated along the cutting edge. As a result, a cutting force necessary in the displacement direction for cutting the hairs is limited substantially, which results in a substantial improvement of the shaving performance and the shaving comfort of the shaving head. The hair manipulator also provides protection against incised wounds and skin irritations. During the displacement of the shaving head over the skin, the hair manipulator smoothes the skin directly in front of the cutting edge in a direction parallel to the displacement direction, so that relatively large skin creases in front of the cutting edge, which might cause incised wounds, are largely precluded. As the hair manipulator is reciprocated in a direction parallel to the cutting edge, the hair manipulator smoothes the skin directly in front of the cutting edge also in a direction parallel to the cutting edge, so that also relatively small skin creases between the teeth of the hair manipulator, which might cause minor incised wounds or skin irritations, are largely precluded. A drawback of the known shaving head and the known shaver resides in that the above-mentioned shaving performance and protection against incised wounds and skin irritations can only be achieved if the hair manipulator, which is drivable with respect to the cutting member, is situated, viewed in directions perpendicular to the cutting edge, in an accurately determined position with respect to the cutting member, with only a relatively small distance between the hair manipulator and the cutting member being permissible, viewed particularly in a direction perpendicular to the cutting edge and perpendicular to the displacement direction. For this reason, the shaving head must comprise a very accurate guide for displacements of the hair manipulator with respect to the cutting member, so that very high requirements are imposed regarding the accuracy of the construction used and regarding the permissible dimensional tolerances in the manufacture of the shaving head. As a result, the construction of the shaving head, and the manufacture thereof, are relatively complicated. It is an object of the invention to provide a shaving head and a shaver of the types mentioned in the opening paragraphs, by means of which also a high degree of protection against incised wounds and skin irritations is provided, while, in addition, the above-mentioned drawback of the known shaving head and the known shaver is precluded as much as possible. To achieve this goal, a shaving head in accordance with the invention is characterized in that the hair manipulator is arranged in a fixed position with respect to the cutting member, with the cutting member and the hair manipulator being jointly drivable in a direction substantially parallel to the cutting edge. To achieve this goal, a shaver in accordance with the invention is characterized in that the shaving head used therein is a shaving head in accordance with the invention. Since the hair manipulator is arranged in a fixed position with respect to the cutting member, the shaving head does not have to comprise an accurate guide for displacements of the hair manipulator with respect to the cutting member. In the manufacture of the shaving head, the hair manipulator is, for example, secured in a fixed position to the cutting member, so that a desirable, accurate position of the hair manipulator with respect to the cutting member is achieved in a comparatively simple and reliable manner. Since it has been found that the position of the cutting member / hair manipulator unit thus obtained with respect to the shaving head does not have to be nearly as accurate as the position of the hair manipulator with respect to the cutting member, the shaving head may be provided with a comparatively simple guide for joint displacements of the cutting member and the hair manipulator with respect to the shaving head. As the cutting member and the hair manipulator can be jointly driven in a direction substantially parallel to the cutting edge, skin creases are substantially precluded by the hair manipulator when the shaving head is moved over the skin, so that, like in the known shaving head and the known shaver, the hair manipulator provides a high degree of protection against incised wounds and skin irritations. A particular embodiment of a shaving head in accordance with the invention is characterized in that the hair manipulator and the cutting member are integrated into a single part. In the manufacture of said part, the hair manipulator can be relatively readily provided or formed on the cutting member with the desired accuracy. This results in a substantial further simplification of the construction and the assembly of the shaving head. A particular embodiment of a shaver in accordance with the invention is characterized in that the shaver is provided with means for generating reciprocating displacements of the cutting member, which displacements at least comprise a component in a direction parallel to the displacement direction of the shaving head. As a result of said reciprocating movements of the cutting member in a direction parallel to the displacement direction of the shaving head, the cutting force necessary in the displacement direction to cut the hairs is limited substantially, resulting in a substantial improvement of the shaving performance and the shaving comfort of the shaver. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. In the drawings: Fig. 1 shows an embodiment of a shaver in accordance with the invention, which is provided with a shaving head in accordance with the invention, Fig. 2 shows a part of the shaving head of the shaver shown in Fig. 1, Fig. 3a shows an integrated part of a further embodiment of a shaving head in accordance with the invention, and Fig. 3b is a sectional view taken on the line Illb-IIIb in Fig. 3a. Fig. 1 shows an embodiment of a shaver 1 in accordance with the invention, which comprises a housing 3 on which a shaving head 5 in accordance with the invention is detachably secured by means of securing means 7 which, for the sake of simplicity, are only diagrammatically shown in the Figure and may be of a customary type which is known per se. The housing 3 accommodates an electric motor 9, a battery 11 for feeding the motor 9, and an electric control unit 13 for controlling the motor 9. The motor 9 can be switched on and off by means of a switch 15 provided on the housing 3. As shown in Figs. 1 and 2, the shaving head 5 is provided with a cutting member 17, which is plate-shaped in the embodiment shown and provided with a straight cutting edge 19 for cutting hairs growing from skin. The cutting edge 19 extends parallel to an X-direction which is perpendicular to a displacement or shaving direction Y of the shaving head 5. The shaving head 5 further comprises a hair manipulator 21 which, in the embodiment shown, is provided with a comb 23. Said comb 23 is provided on a carrier 25 of the hair manipulator 21 and provided with teeth 27 which extend substantially perpendicularly to the cutting edge 19 and which are arranged, viewed in the displacement direction Y of the shaving head 5, directly in front of the cutting edge 19. It is to be noted that the teeth 27 are provided substantially throughout the length of the cutting edge 19, but in Fig. 2 only a few teeth 27 are shown for the sake of simplicity. As shown in Figs. 1 and 2, the cutting member 17 is secured in a fixed position on the carrier 25 of the hair manipulator 21, so that the comb 23 of the hair manipulator 21 is arranged in a fixed position with respect to the cutting member 17. The plate-shaped cutting member 17 is secured, in the embodiment shown, to a flat upper side 29 of the carrier 25 by means of securing means 31 , which are only diagrammatically shown in the Figs. 1 and 2 and may be of a customary type which is known per se. Viewed in a direction parallel to the X-direction, the carrier 25 is displaceably guided with respect to a frame 33 of the shaving head 5 and is provided, for this purpose, with guiding members 35, 37 for co-operation with guide grooves 39, 41 which extend parallel to the X-direction and are provided in the frame 33. The carrier 25 is drivable in a direction parallel to the X-direction by means of a drive mechanism 43 of the shaver 1, which is arranged in the housing 3 and comprises the above-mentioned motor 9. The drive mechanism 43 further comprises an outgoing shaft 45 of the motor 9 and a pin 47, which is eccentrically provided on said drive mechanism, and which serves to co-operate with a groove 49 formed in the carrier 25. Viewed in a direction parallel to the X-direction, the groove 49 has a width which corresponds to a diameter of the pin 47, so that a rotation of the outgoing shaft 45 of the motor 9 is converted to reciprocating joint displacements of the hair manipulator 21 and the cutting member 17 secured thereto with respect to the frame 33 of the shaving head 5 in a direction parallel to the X-direction. When a user moves the shaver 1 with the shaving head 5 in the displacement direction Y over a skin 51 to be treated, the hair manipulator 21 provides protection against incised wounds and skin irritations. Since the hair manipulator 21 is arranged directly in front of the cutting edge 19 of the cutting member 17, viewed in the displacement direction Y, the hair manipulator 21 smoothes the skin 51 directly in front of the cutting edge 19 in a direction parallel to the displacement direction Y, so that relatively large skin creases in front of the cutting edge 19, which could be subject to incised wounds inflicted by the cutting edge 19, are largely precluded. Since the hair manipulator 21 is reciprocated in a direction parallel to the cutting edge 19, the hair manipulator 21 smoothes the skin 51 directly in front of the cutting edge 19 also in a direction parallel to the cutting edge 19, so that also relatively small skin creases between the teeth 27 of the hair manipulator 21. which could lead to smaller incised wounds or skin irritations, are also largely precluded. When the shaving head 5 is moved over the skin 51, hairs present on the skin 51, such as the hair 53 shown in Fig. 1, are caught between the teeth 27 of the hair manipulator 21 and thus reach the cutting edge 19 which subsequently cuts the hairs. A sufficient protective effect of the hair manipulator 21 is obtained, for example, if the width of and the interspace between the teeth 27, viewed in a direction parallel to the X-direction, ranges between 0.1 and 0.4 mm, the hair manipulator 21 being reciprocated at a frequency of approximately 100 Hz or higher, and an amplitude between approximately 0.05 mm and 0.250 mm. It has been found that a sufficient protective effect of the hair manipulator 21 is achieved only if the teeth 27 of the hair manipulator 21 are in a predetermined accurate position with respect to the cutting edge 19 of the cutting member 17. Particularly a slit 55, shown in Fig. 1, which is situated between the cutting edge 19 and the teeth 27, viewed at right angles to the cutting edge 19, must be smaller than a predetermined relatively small limiting value. Since the cutting member 17 and the hair manipulator 21 are secured in fixed positions with respect to each other in the shaving head 5 in accordance with the invention by means of securing means 31. the necessary accurate position of the teeth 27 with respect to the cutting edge 19 can be relatively readily and reliably achieved during the manufacture of the shaving head 5 by means of relatively simple securing means 31. Since it has been found that a considerably less accurate position of the cutting member 17 and the hair manipulator 21 attached thereto with respect to the frame 33 of the shaving head 5 is permissible, a comparatively small accuracy of the guide members 35, 37 of the hair manipulator 21 and of the guide grooves 39, 41 of the frame 33 is sufficient. Thus, as regards the shaving head 5, the protective effect of the hair manipulator 21 is achieved by means of a manufacturing process for the shaving head 5 and a construction of the shaving head 5 which are much simpler than a manufacturing process and a construction necessary for a shaving head with a comparable protective effect, such as the known shaving head disclosed in EP-A-0 855 256, in which the cutting member is arranged in a fixed position in the shaving head and a very accurate guidance of the hair manipulator with respect to the cutting member must be applied. In the shaving head 5 in accordance with the invention, the hairs caught between the teeth 27 of the hair manipulator 21 are reciprocated by said hair manipulator 21 in a direction substantially parallel to the cutting edge 19. As the cutting member 17 and the hair manipulator 21 are secured in fixed positions with respect to each other, the hairs are almost not reciprocated along the cutting edge 19, so that the shaving head 5 does not limit the necessary cutting forces in a way the shaving head known from EP-A-0 855 256 does. In order to still achieve a limitation of the cutting forces in a direction parallel to the displacement direction Y of the shaving head 5, the shaver 1 is provided with means 57 for generating reciprocating movements of the cutting member 17 in a direction parallel to the displacement direction Y. It has been found that the necessary cutting forces are limited substantially under the influence of such displacements of the cutting member 17 in a direction parallel to the displacement direction Y. In the embodiment shown, said means 57 are constructed in a particularly simple way. said means 57 comprising an imbalance mass 59 which is eccentrically secured to the outgoing shaft 45 of the motor 9. However, said means may alternatively be differently embodied. In addition, in other embodiments wherein the motor drives both the hair manipulator and said means, a transmission may be applied between the motor and said means and/or between the motor and the hair manipulator, which transmission enables a desired frequency ratio between the displacements of the cutting member parallel to the X-direction and parallel to the Y-direction to be obtained. In the above-described shaving head 5 in accordance with the invention, the cutting member 17 and the hair manipulator 21 are two separate parts which are secured to one another during the manufacture of the shaving head 5. However, the invention also comprises embodiments wherein the cutting member and the hair manipulator are integrated into a single part, resulting in a substantial further simplification of the construction and the assembly of the shaving head. An example of such an integrated part 61, which is used in a further embodiment of a shaving head in accordance with the invention, is shown in Figs. 3a and 3b. The further embodiment of the shaving head is substantially identical in other repects to the above-described shaving head 5. The integrated part 61 comprises a plate-shaped metal carrier 63 wherein grooves 65 are formed by means of a customary machining operation which is known per se, and rounded teeth 67 being provided on this plate-shaped metal carrier by means of a customary machining process which is known per se. In addition, an upper side 69 of the carrier 63 is processed such that a cutting edge 71 is formed between each pair of adjacent teeth 67. The integrated part 61 further comprises guide members, not shown in the Figures, for guiding the part 61 with respect to the shaving head in a direction parallel to the cutting edges 71.

Claims: CLAIMS: 1. A shaving head provided with a cutting member having a cutting edge for cutting hairs growing from skin and with a hair manipulator which, viewed in a displacement direction of the shaving head, is arranged in front of the cutting edge and which is drivable in a direction substantially parallel to the cutting edge for moving the hairs in a direction substantially parallel to the cutting edge, characterized in that the hair manipulator is arranged in a fixed position with respect to the cutting member, with the cutting member and the hair manipulator being jointly drivable in a direction substantially parallel to the cutting edge. 2. A shaving head as claimed in claim 1 , characterized in that the hair manipulator and the cutting member are integrated into a single part. 3. A shaver comprising a shaving head and a drive mechanism for driving the shaving head, the shaving head being provided with a cutting member having a cutting edge for cutting hairs growing from skin and with a hair manipulator which, viewed in a displacement direction of the shaving head, is arranged in front of the cutting edge and which is drivable, by means of the drive mechanism, in a direction substantially parallel to the cutting edge for moving the hairs in a direction substantially parallel to the cutting edge, characterized in that the shaving head is a shaving head as claimed in claim 1 or 2. 4. A shaving head as claimed in claim 3, characterized in that the shaver is provided with means for generating reciprocating displacements of the cutting member, which displacements at least comprise a component in a direction parallel to the displacement direction of the shaving head.

Inventors: PRAGT JOHAN, PRAGT, JOHAN
Applicants: KONINKL PHILIPS ELECTRONICS NV, KONINKLIJKE PHILIPS ELECTRONICS N.V.
Application year: 2000
Main classification: B26B21
IPC codes: B26B19, B26B21