EP0693988B1

EP0693988B1 - Shaving head for electric razors

Info

Publication number: EP0693988B1
Application number: EP94909929A
Authority: EP
Inventors: Matthias Wetzel
Original assignee: Braun GmbH
Current assignee: Braun GmbH
Priority date: 1993-04-13
Filing date: 1994-03-04
Publication date: 1996-12-11
Anticipated expiration: 2014-03-04
Also published as: DE4312060C1; JPH08508434A; JP3727336B2; EP0693988A1; US5669138A; HK33797A; WO1994023913A1; AT146113T

Abstract

An electric razor has at least one shaving head (8, 9, 10) which consists of an upper cutting element (11, 12, 13) and a lower cutting element (18). The upper cutting element (12) having a contact surface is formed by a wall element (30) having slits (23, 24) and lands (25, 26, 27, 28) and by at least another wall element (29, 31) which forms an angle with said wall element (30). Engagement elements (E) which project over the outer profile of the wall element (29, 31) which forms an angle with wall element (30) are provided on the wall element (30) which forms the contact surface.

Description

The invention relates to a dry shaving apparatus with at least one shaving head consisting of an upper knife and a lower knife.
A dry shaver of the type mentioned is known from DE-GM 82 27 546. The top knife of the shaving head consists of a combination of a screen shaving foil part and a comb shaving part. In the comb shear part, slit-forming slits are provided which extend into the angled side wall of the comb shear part facing away from the screen shear film, at least two adjacent slits in the angled side wall forming a common opening. A cutting bar for the bottom knife of the comb shear part is ground in the webs merging into the angled side wall and the teeth ending in front of the angled side wall. The teeth thus ending in front of the angled webs cannot perform a threading function for longer hair lying against the skin to be shaved and already held firmly by the angled webs, but only a cutting function for hair that has entered the cutting area.
From DE-AS 1 111 062 a dry shaver with a shaving head is known, consisting of a combination of a screen shaving film part with a chamber shaving part. The comb shear part has two shear surfaces separated by a U-shaped recess. In the shear surfaces, slit-forming slits are provided which extend into the angled outer wall elements which support the shear surfaces, with four adjacent slits forming a common opening in the angled side wall.
A dry shaving apparatus is known from US-A-21 81 038, the shaving head of which is formed from an essentially U-shaped shaving plate and a triangular undercutter assigned to it. In order to form cutting elements, round holes as well as slots extending transversely to the longitudinal extension of the shear plate and extending into the wall elements angled to the shear plate are provided in the flat contact surface of the shear plate, the webs in the two transition areas from the flat contact surface to avoid sharp edges are bulged like an arc to the two angled wall elements.
GB-A-1 367 445 discloses a dry shaving apparatus with two short hair cutting systems running parallel to one another and a long hair cutting system arranged between them in a height-adjustable manner. The long hair cutting system is T-shaped and has two rows of sharp teeth, each of which is composed of a cutting comb and a cutting blade and runs parallel to the short hair cutting systems, so that this long hair cutting system can also be used for trimming purposes - see Fig. 12-.
The object of the invention is to improve the shaving head in a dry shaver of the type mentioned in such a way that an optimal and at the same time skin-friendly threading of hair into the cutting area formed by the upper knife and lower knife is ensured.
According to the invention, this object is achieved by the combination of features specified in claim 1. A major advantage of the invention is that by means of the freely protruding An upper knife is formed at the ends of the web-like threading elements with a threading comb in front of the cutting area, the freely projecting comb ends of which perform a combing function and thus optimally design the detection of hair to be shaved and the threading process into the cutting area formed by the upper knife and lower knife. The threading elements upstream of the cutting area capture hair lying close to the skin as well as hair that swirls out of the skin in the course of the movement of the shaving head over the skin and thread it into the cutting area.
In a further embodiment of the invention it is provided that the threading elements are formed by a tangential extension of the webs forming the contact surface of the upper knife. The threading elements are therefore part of the material from which the upper knife is formed. The upper knives according to the invention are produced using stamping processes and pressing processes and are given a U-shaped or cup-like shape by these processes, with the simultaneous formation of the webs of the upper knife which form both the threading elements and the cutting webs. The production of the threading elements therefore requires no additional material and time.
An optimal threading effect of hair can be achieved according to the invention in that all of the webs of the wall element forming the contact surface are extended to form threading elements projecting beyond the contour of the wall element provided at an angle thereto.
According to an embodiment of the invention which strengthens the stability of the upper knife, it is provided that optionally some webs of the wall element forming the contact surface are formed from components of the wall elements provided, the longer webs provided between the shorter webs with the free ends are protruding from at least one angled wall element. This embodiment also enables, for example, a reduction in the wall thickness of the contact surface of the upper knife, which is adapted to the required stability of the upper knife, and consequently a cut close to the skin of the hair to be cut.
A further embodiment of the invention is characterized in that the contact surface of the upper knife, which is enlarged by means of the projecting threading elements, is essentially flat.
A particularly skin-friendly threading of hair into the cutting area is ensured according to the invention in that at least the edges of the webs that come into contact with the skin and those of the threading elements are rounded.
According to a particularly advantageous embodiment of the invention, the upper knife is U-shaped and the threading elements are provided as part of the webs of the wall element forming the contact surface, projecting from the outer contour of at least one wall element angled to it.
According to another embodiment of the invention, the upper knife is pot-shaped and the threading elements are formed as a component of the webs of the wall element forming the contact surface, projecting from the outer contour of the ring-shaped wall element and / or another ring-shaped wall element.
A further embodiment, which strengthens the stability of the upper knife, is characterized according to the invention in that the webs of the contact surface formed by slots are connected via a connector jetties are connected to each other.
Further essential advantages result from the different areas of application of the invention. According to one embodiment of the invention, the threading elements are provided on the upper knife of a shaving head designed as a short hair cutter. Such upper knives have a pot-like shape, with cutting webs formed by slots, which according to the invention are used to form threading elements.
According to a further embodiment of the invention, the threading elements are provided on the upper knife of a shaving head designed as a long hair cutter. Such upper knives preferably have a U-shaped shape, with cutting webs formed by slots, which according to the invention are used to form threading elements.
According to a preferred embodiment of the invention, the shaving head designed as a long hair cutter and having threading elements is arranged between two shaving heads designed as short hair cutters, and the threading elements are each provided adjacent to the upper knives of the short hair cutters on the upper knife of the long hair cutting shaving head. A very important advantage of this embodiment arises in that the threading elements provided on the upper knife of the long hair trimmer, each adjacent to the respective upper knife of the short hair trimmer, are used alternately, depending on the direction of movement of the shaving heads over the skin to be shaved, in order to increase the existing length Thread hair into the cutting area of the long hair trimmer for cutting. After the long hair cut, these shortened hairs get into the respective cutting area of the adjacent short hair cutter in the further course of the movement of the shaving heads, in order to be further shortened there.
According to a further embodiment of the invention it is provided that the shaving head having threading elements is relatively movable in the vertical direction (arrow direction A) and is arranged to at least one of the shaving heads designed as short hair cutters.
Some preferred exemplary embodiments are shown in the following description and the drawings. Show it:

Fig. 1: part of a dry shaving apparatus with three shaving heads in perspective,
Fig. 1a: a removable frame with differently designed upper knives in perspective,
Fig. 2: 2 shows an exploded view of components of a shaving head designed as a long hair cutter,
Fig. 2a: 3 shows a section through the U-shaped profile of an upper knife having threading elements,
Fig. 3: a partial view of a U-shaped upper knife with threading elements in perspective,
Fig. 4: a partial view of a U-shaped upper knife with threading elements in perspective,
Fig. 5: a partial view of a U-shaped upper knife with threading elements in perspective,
Fig. 6: a partial view of a U-shaped upper knife with threading elements in perspective,
Fig. 7: 2 shows a side view of a razor with three circular upper knives with threading elements,
Fig. 8: 7 shows a partial section through the shaving head and through a cup-shaped upper knife with threading elements of the shaving apparatus according to FIG. 7,
Fig. 9: a section through a pot-shaped upper knife with threading elements,
Fig. 10: a section through a pot-shaped upper knife with threading elements,
Fig. 11: a view of the top of the pot-shaped upper knife of FIG. 10.

In Fig. 1 the upper part of an electric dry shaver is shown, the housing with 1, the on and off switch with 2, the long-hair trimmer provided with cutting teeth with 3, the support arms extending in the extension of the narrow sides 4 and 5 with 6 and 7 and the on these support arms 6, 7 razor head pivotally mounted about an axis xx is denoted by RK.
In the razor head RK three parallel shaving heads 8, 9 and 10 are provided, of which the two outer shaving heads 8 and 10 are designed as short hair cutters and the shaving head 9 arranged between these shaving heads 9 and 10 is designed as a long hair cutter. The upper knives 11 and 13 of the short-hair cutter shaving heads 8 and 10 are fastened to an interchangeable frame 15 which is detachable from the shaving head frame 14. The upper knife 12 of the shaving head 9 is, as with reference to FIGS. 2 and 2a shown and described, part of an assembly consisting of the upper knife 12, a lower knife 18, a pressure spring 19 and a coupling piece 20 for transmitting a drive movement. This assembly is mounted as a long-hair trimmer shaving head 9 on the end walls 16 and 17 of the change frame 15 either immobile or movable in the vertical direction - arrow direction A -.
According to a further embodiment, the upper knife 12 of the shaving head 9 can either be immovably fastened directly on the end walls 16 and 17 of the change frame 15 or of a shaving head frame carrying or surrounding shaving heads or can be arranged to be movable in the vertical direction - arrow direction A. In such an embodiment, the lower knife 18 required for cutting is coupled to the drive of the electric dry shaving apparatus via a coupling piece 20 and is pressed against the upper knife 12 by a pressure spring 19.
Further details of a removable frame 15 removed from the shaving head frame 14 according to FIG. 1 are shown in FIG. 1a and are described in more detail below. The arched clamped shaving foils of the upper cutters 11 and 13 provided for a short haircut are each attached to the longitudinally extending side walls 21 and 22 of the interchangeable frame 15 and to webs provided between the end side walls 16, 17 - not visible. The U-shaped upper knife 12 of the shaving head 9 provided for cutting long hair is arranged to be movable on the end walls 16 and 17 in the vertical direction - arrow direction A -. In this exemplary embodiment, the upper knife 12 consists of a sheet metal part in which, for example by using a stamping process, a plurality of slots 23 and further webs 24 partially connecting them in the longitudinal direction of the upper knife 12, 25, 26, 27, 28 are formed. The sheet metal part is then pressed into a U-shape by means of a pressing process, in such a way that the webs 25, 26, which run transversely to the longitudinal direction of the upper knife 12, protrude in relation to the outer contour of the two wall elements 29 and 31, which run at an angle to the wall element 30. see sectional view of Fig. 2a.
The respective part of the webs 25, 26 protruding from the wall elements 29, 31 effects as the threading element E the threading of hair into the cutting area of the upper knife 12.
In the exemplary embodiment shown in FIG. 2, the arrangement and shape of the slots 23 and 24 with respect to one another is also made such that a web 27 running in the longitudinal direction of the upper knife 12 is formed in the wall element 30, as well as a plurality extending transversely to the web 27 the U-shape of the upper knife 12 corresponding webs 28 are formed. The number of webs 28 depends on the application, depending on the stability of the upper knife 12 required in the individual case, and is therefore not limited to the number shown in FIG. 2. In the exemplary embodiment shown in FIG. 2, four webs 25 and 26 are provided between two webs 28 on both sides of the web 27, which have a cutting function in the area of the lower knife 18 which bears against the upper knife 12 under pressure of the pressure spring 19 and with which with the angled wall elements 29 and 31 projecting ends as threading element E perform a threading function in the course of the movement of the upper knife 12 over the skin in the respective direction. To avoid skin irritation, the edges of the webs 25 to 28 that come into contact with the skin, in particular the edges of the threading elements E formed by webs 25 and 26, are rounded. The number of webs 25, 26 between two webs 28 can be changed taking into account a stability required for the upper knife 12. The in the wall elements 29 and 31, slots 24 delimited by the respective webs 28, with the inclusion of a threading process carried out by the threading elements E of the webs 25 and 26, enable unhindered penetration of longer hair into the cutting area of the shaving head 9 designed as a long hair cutter.
In order to combine the shaving head 9 according to FIG. 2 into a complete assembly, the pressure spring 19 is coupled to the coupling piece 20. The lower knife 18 is then fastened to the coupling piece 20 by means of a pin 34 and inserted into the interior of the U-shaped upper knife 12. By means of the two carrier elements 32, 33, each of which comes to rest on one end of the pressure spring 19 and thus serve as a support for this spring, the lower knife 18, the pressure spring 19 and the coupling piece 20 are combined with the upper knife 12 to form an assembly, whereby the carrier elements 32, 33 penetrating pins 35 to 38 are firmly connected to the wall elements 29 and 31 of the upper knife 12, for. B. by means of a welded joint. This assembly, which is preassembled into a complete shaving head 9, is then either fastened to the end walls 16 and 17 of the interchangeable frame 15 — see FIGS. 1 and 2, or is mounted in the direction of arrow A and can be moved up and down.
The combination shown in FIGS. 1 and 1a of two shaving heads 8 and 10 designed as short hair cutters with a shaving head 9 arranged between these shaving heads 8 and 10 and designed as long hair cutters 9 according to FIG. 2 ensures, in particular when the razor head RK moves in the direction of the arrows B, a skin-friendly threading of long hair into the cutting area of the shaving head 9 with an immediately following short hair cut through the adjacent shaving head 8 or 10. By means of a movable mounting of the shaving head 9 in the changing frame 15 or in a shaving head frame - Not shown - a so-called skin walk effect can be achieved, which favors both the detection, threading and cutting of long hair and the subsequent cutting of short hair.
FIG. 3 shows a further embodiment of an upper knife 12 with threading elements E protruding beyond the contour of the wall elements 29, 31, which are part of the webs 25, 26. The L-shaped webs 25, 26 and the U-shaped webs 28 consist of components of the wall elements 29, 30, 31 and are formed by introducing through slots 23 and 24 into the wall elements 29, 30, 31. In order to ensure that long hair is threaded in both directions of movement according to arrow B, the webs 25 with the rounded threading elements E are provided opposite to the webs 26 which have threading elements E and extend on the upper knife 12. The upper side of the webs 25 and 28 or the proportionate component of the wall element 30 represents the contact surface of a shaving head 9 equipped with such an upper knife 12 that comes into contact with the skin.
FIG. 4 shows a further embodiment of an upper knife 12 with threading elements E protruding beyond the contour of the wall elements 29, 31, which are part of the webs 25, 26. The alignment and arrangement of the webs 25, 26 and 28 corresponds to the embodiment according to FIG. 3, with the difference that the webs 25, 26 and 28 which perform a threading function and cutting function are connected to one another by a web 27 running in the longitudinal direction of the upper knife 12. The web 27 increases the stability of the U-shaped profile.
5 shows a further embodiment of a U-shaped upper knife 12, in which, in contrast to the embodiment according to FIG. 4, the webs 25, 26, 28 are connected to one another by webs 27 which run obliquely to the longitudinal direction of the upper knife 12.
Fig. 6 shows a further embodiment of a U-shaped upper knife 12, in which the comb geometry of the webs 25, 26, 28 exerting a threading element E and cutting elements is designed in such a way that on a continuous web formed by webs 27 transversely on both sides to the longitudinal direction of the upper knife 12 webs 25, 26 are provided with threading elements E, which protrude beyond the contour of the U-profile. The number of webs 25, 26 to be provided between two webs 28 corresponding to the U-profile of the upper knife 12 can be changed and is not limited to three webs 25, 26 running parallel to one another, as shown in FIG. 6.
FIG. 7 shows a shaving apparatus with three shaving heads 8 each consisting of an upper knife 11 and a lower knife 18 - see FIG. 8. The upper knife 11 of the shaving heads 8 is pot-shaped - see FIGS. 8 to 11 -, as a result of which a flat wall element 30 and, angled to this, an annular wall element 31 is formed. For the purpose of designing an annular cutting area, a pot-like depression 39 is provided centrally in the wall element 30, the wall elements of which are designated 29 and 40. The cutting webs 25, 26, 28 are formed by a plurality of slots 23 which penetrate both the wall element 30 in the annular cutting area and the annular wall element 31 which extends at an angle thereto. In order to form webs with webs 26 and 25 projecting from the angled wall element 31 - see FIG. 9 - and from the wall element 29 - see FIGS. 10 and 11 - the projecting web part of which in each case performs a threading function as threading element E, at least two are first Slots 23 located on both sides of a web 26 are connected to one another by a slot 24 made in wall element 31 - see FIG. 9 - or at least two slots 23 located on both sides of a web 25 by a slot 24 made in wall element 29 - see FIGS. 10 and 11 . Then the wall part of the angled wall element 31 (FIG. 9) located on the web 26 or the wall part of the angled wall element 29 located on the web 25 is z. B. brought by means of a pressing process into a plane with the contact surface of the wall element 30 of the upper knife 11 coming into contact with the skin - see FIGS. 9 and 10.
The embodiment according to FIG. 9 consists of a combination of webs 26 and 28, the threading elements E as part of the webs 26 protruding from the angled component and the webs 28 being formed by the wall elements 29, 30, 31. The number of webs 26 which can be provided between two webs 28 and which are provided with threading elements E can be selected as desired.
The embodiment according to FIGS. 10 and 11 consists of a combination of webs 25, 26 and 28. The webs 26 provided with threading elements E are opposite the wall element 31 and the webs 25 provided with threading elements E are protruding from the wall element 29 and consequently come during the shave, depending on the direction of movement of the shaving head 8 over the skin, to be used alternately for both longer and shorter hair in the cutting area formed by the webs 25, 26 of the upper knife 11 and the lower knife 18 associated therewith - see FIG. 8 to thread for cutting. The webs 28 formed by the wall elements 29, 30, 31 give the upper knife 11 the required stability. The number and the type of arrangement of the provision between two webs 28 with Web 25 and 26 provided with threading elements E are not limited to the embodiment shown in FIG. 11. The embodiments shown in FIGS. 2, 3, 4, 5 and 6, for example, can also be used with an upper knife 11 intended for a razor according to FIGS. 7 and 8.

Claims

A dry shaving apparatus, with at least one shaving head (8, 9, 10) comprised of an outer cutter (11, 12, 13) and an inner cutter (18), whereof the outer cutter (12 ) which includes an engaging surface is formed by a wall element (30) having slots (23, 24) and bridge members (25, 26, 27, 28), and by at least one further wall element (29, 31) disposed in an angled relationship to said wall element (30), with hair-feeding means (E) being provided on the wall element (30) forming the engaging surface, said hair-feeding means being configured in the manner of bridge members and having ends projecting freely relative to the angled wall element (29, 31), wherein the freely projecting ends protrude beyond the outer contour of the angled wall element (29, 31) and lie in the plane of the wall element (30) forming the engaging surface.
The dry shaving apparatus as claimed in claim 1, characterized in that said hair-feeding means (E) are formed by a tangential extension of the bridge members (25, 26, 27) forming the engaging surface of the outer cutter (12).
The dry shaving apparatus as claimed in any one of the preceding claims, characterized in that, for the purpose of providing hair-feeding means (E), all of the bridge members of the wall element (30) forming the engaging surface are extended so as to protrude beyond the contour of the wall element (29, 31) arranged in an angled relationship thereto.
The dry shaving apparatus as claimed in any one of the claims 1 or 2, characterized in that selected bridge members of the wall element (30) forming the engaging surface are formed from component parts of the wall elements (29, 30, 31) provided, with the longer bridge members (25, 26) that are provided between shorter bridge members (28) having their free ends configured in a protruding fashion relative to at least one angled wall element (29).
The dry shaving apparatus as claimed in any one of the preceding claims, characterized in that the outer cutter (12) engaging surface which is increased by means of the protruding hair-feeding means (E) is of an essentially planar configuration.
The dry shaving apparatus as claimed in any one of the preceding claims, characterized in that at least the edges of the bridge members (25, 26, 27) contacting the skin as well as the edges of the hair-feeding means (E) are of a rounded configuration.
The dry shaving apparatus as claimed in any one of the preceding claims, characterized in that the outer cutter (12) is of a U-shaped configuration, and that the hair-feeding means (E), as component parts of the bridge members (25, 26) of the wall element (30) forming the engaging surface, are provided such as to protrude relative to the outer contour of at least one wall element (29, 31) arranged at an angle thereto.
The dry shaving apparatus as claimed in any one of the claims 1 to 6, characterized in that the outer cutter (11) is of a cup-shaped configuration, and that the hair-feeding means (E), as component parts of the bridge members (25, 26) of the wall element (30) forming the engaging surface, are configured such as to protrude relative to the outer contour of the annular wall element (31) and/or a further annular wall element (29).
The dry shaving apparatus as claimed in any one of the preceding claims, characterized in that the bridge members (25, 26) of the engaging surface which are formed by slots (23, 24) are mutually connected by means of connecting bridge members (27).
The dry shaving apparatus as claimed in any one of the preceding claims, characterized in that the hair-feeding means (E) are provided on the outer cutter (11) of a shaving head configured as a short-hair cutter unit.
The dry shaving apparatus as claimed in any one of the claims 1 to 9, characterized in that the hair-feeding means (E) are provided on the outer cutter (12) of a shaving head (9) configured as a long-hair cutter unit.
The dry shaving apparatus as claimed in any one of the preceding claims, characterized in that the shaving head (9) configured as a long-hair cutter unit provided with hair-feeding means (E) is disposed between two shaving heads (8, 10) configured as short-hair cutter units, and that the hair-feeding means (E) are provided on the outer cutter (12) of the long-hair cutter unit (9) adjacent to the respective outer cutters (11, 13) of the short-hair cutter units.
The dry shaving apparatus as claimed in claim 12, characterized in that the shaving head (9) provided with hair-feeding means (E) is arranged so as to be movable in a vertical direction (direction of arrow A) relative to at least one of the shaving heads (8, 10) configured as short-hair cutter units.