DRY-SHAVING APPARATUS

Abstract: The invention relates to a dry-shaving apparatus comprising an external shear member (3) formed with hair-entry apertures (4) and an internal shear member (6) which is drivable relative to the external shear member (3) and which comprises a carrier (7) with at least one cutter (8). The cutter (8) is provided with a resilient element, at least a part of the cutter being deflexible against the action of the resilient (29) element in a direction substantially opposed to the direction of driving.

Description: The invention relates to a dry-shaving apparatus comprising an external shear member formed with hair-entry apertures and an internal shear member which can be rotatably driven relative to the external shear member by a motor and which internal shear member comprises a carrier and at least one cutter and a resilient element between the motor and the cutter, the cutter being movable against the action of the resilient element in a direction substantially opposed to the direction of driving. Such a dry-shaving apparatus is known for example from US-A-3 116 551. In this known construction a coil spring is provided between the motor shaft and the carrier to effect a flexible spring drive. It is the object of the invention to improve the shearing action of the shaving apparatus and to this end the invention is characterized in that the resilient element is constructed as a blade spring which acts between the carrier and the cutter. After a hair has been severed the pressure exerted by the resilient element ensures an accelerated return of the cutter to its original position. As a result of this accelerated return, the severed hair which is situated before the cutter is propelled away so that the cutter tends to be soiled less rapidly. This effect is much more pronounced with the construction according to the invention than with the rotary shaver according to US-A 3 116 551 where the ensemble of the internal shear member has to be accelerated. From the EP-A-086 536 a vibratory shaver is known in which the cutters are formed by flexible elements of plate material. Here the cutters are arranged in pairs whereby one of the cutters of a pair can operate as a hair pulling element in front of the other cutter of the pair. A special embodiment is defined in the appended subsidiary Claim. An embodiment of the invention will now be described in more detail, by way of example, with reference to the Figures. Figure 1 is a plan view of a dry-shaving apparatus comprising three external shear members; Figure 2 shows the dry-shaving apparatus of Figure 1 in a side view and partly in a sectional view taken on the line II-II in Figure 1; Figure 3 shows diagrammatically a combination of an internal and an external shear member, the left-hand half of the Figure being a view in which the external shear member is partly cut away. Figure 4 shows in the left-hand half a plan view and in the right-hand half an underneath view of the internal shear member of Figure 3. The dry-shaving apparatus as shown in Figures 1 and 2 comprises a housing 1 of which a part is constructed as a holder 2 for three external shear members 3. The shear members 3 are formed with hair-entry apertures 4 in the form of slits, represented as single lines in Figure 1 and situated in an annular shaving portion 5 of the external shear member. As is shown in the partly sectional view of Figure 2, an internal shear member 6 is arranged on the inner side of an external shear member 3. This internal shear member 6 mainly comprises a carrier 7 and cutters 8 which extend axially towards the shaving portion 5. The internal shear member 6 is coupled to the electric motor 13 by means of a hollow spindle 9 (Figure 2), gear wheels 10 and 11 and a shaft 12, so that this shear member is rotatable relative to the associated external shear member 3. The gear wheel 10 is rotatably journalled on a pin 14 which is secured in a mounting plate 15. This gear wheel is formed with a recess 16 which is closed by a cover plate 17. This recess is engaged by a flange 18 at the end of the hollow spindle 9. By giving the flange 18 a non-round, for example square, shape and by giving the recess 16 a corresponding shape a coupling is obtained to transmit the rotation of the gear wheel 10 to the spindle 9. The spring 19, which is largely situated inside the hollow spindle 9 and which is compressed between the hollow spindle 9 and the gear wheel 10, exerts on the spindle 9 a force which is directed towards the internal shear member 6. Since the cylindrical portion 20 of the spindle 9 bears against the shear member 6 this force is transmitted to this shear member and to the external shear member 3 via this internal shear member 6, causing the external shear member 3 to be urged against the holder 2 with the flange 21. The shear members 3 and 6 together with the spindle 9 may be pressed inwards against the action of the spring 19 by external forces which may be produced during use of the dry-shaving apparatus. The coupling for transmitting the rotary movement between the spindle 9 and the internal shear member 6 is obtained in that the spindle 9 is provided with an end portion 22 of rectangular cross-section. This end portion 22 engages a corresponding rectangular coupling aperture 23 in the shear member 6. The coupling to the electric motor 13 as described above is identical for the three internal shear members 6 of the apparatus shown in Figures 1 and 2, the three gear wheels 10 being in mesh with a single central gear wheel 11 on the motor shaft 12. In the combination of an external shear member 3 and an internal shear member 6 as shown in Figures 3 and 4 the internal shear member 6 comprises a disk-shaped carrier 7 with openings 24 in which the cutters 8 are disposed. In the axial direction, indicated by the arrow P₁ the cutters 8 are loaded by resilient arms 25 which form part of a resilient body 26 which is secured to the underside of the carrier 7. The ends 27 of the resilient arms 25 are hook-shaped and engage in openings 28 in the lower end portions 8′ of the cutters 8. The resilient arms are V-shaped and comprise limbs 25′ and 25″. At the upper side of the carrier 7 each cutter 8 is provided with a resilient element 29 which acts between the carrier 7 and the cutter 8 and resiliently supports the cutter substantially in the direction of driving P₂. The resilient elements 29 are constructed as blade springs and integral with a central body 30 of a sheet material which is secured to the upper side of the carrier 7. If during use of the apparatus a hair is caught in a hair-entry aperture 4 the cutting edge 31 on the upper end 8″ of a cutter 8 will penetrate the hair and the hair will be severed by cooperation of the cutter 8 and the external shear member 3. The force produced during cutting comprises a component K₁ which acts on the cutter 8 in a direction substantially opposed to the direction of driving P₂. This force K₁ is capable of pivoting the cutter about the end 27 of the resilient arm 25. As a result of this the upper end 8″ of the cutter 8 will be moved relative to the carrier against the action of the resilient element 29 in the direction of K₁, i.e. in a direction substantially opposed to the direction of driving P₂. For this purpose the openings 24 in the carrier 7 are made sufficiently large. After the hair has been severed the cutter 8 is urged back into the original position shown in Figures 3 and 4 by the resilient element 29. This enables inertial forces occurring during cutting of a hair to be reduced, so as to smooth out load surges to which the motor and the drive mechanism between the motor and the internal shear member 6 are subjected. The above construction counteracts the occurrence of undesired vibrations, provides a smoother operation of the apparatus, and prolongs the life of the moving parts. After a hair has been severed the pressure exerted by the resilient element 29 ensures an accelerated return of the cutter 8 to the position shown in Figures 3 and 4. As a result of this accelerated return of the cutter 8 the severed hair which is situated before the cutter is propelled away, so that the internal shear member 6 tends to be soiled less rapidly. The accelerated return of the cutter under the influence of the resilient element as described in the foregoing is of particular importance in constructions comprising hair-pulling elements because the severed hair, which is situated in front of the cutter or which has adhered to the hair-pulling element, can be propelled away. Therefore the rate of soiling is reduced substantially in such constructions.

Claims: A dry-shaving apparatus comprising an external shear member (3) formed with hair-entry apertures (4) and an internal shear member (6) which can be rotatably driven relative to the external shear member (3) by a motor (13) and which internal shear member (6) comprises a carrier (7) and at least one cutter (8), and a resilient element between the motor (13) and the cutter (8) the cutter being movable against the action of the resilient element in a direction substantially opposed to the direction of driving, characterized in that the resilient element is constructed as a blade spring (29) which acts between the carrier (7) and the cutter (8). A dry-shaving apparatus as claimed in Claim 1, in which the internal shear member (6) is provided with a plurality of cutters (8), characterized in that the resilient elements in the form of blade springs (29) are integral with a central body (30) of a sheet material which is secured to the carrier (7).

Inventors: TIETJENS, EDUARD WILLEM
Applicants: N.V. PHILIPS' GLOEILAMPENFABRIEKEN
Application year: 1987
Main classification: B26B19
IPC codes: B26B19