DE2236297A1 - DRY SHAVER - Google Patents

Description

Dry razor

The invention relates to dry razors for shaving hair on the skin.

The energy consumption of dry shavers is therefore an important factor as it is in battery-powered dry shavers determines the length of the service life of the battery and / or the charging frequency · This affects all types of dry razors he the required power and thus the weight and dimensions of the drive motor used

One of the factors that affect energy consumption is the energy converted in the bearings or the supporting structure on which the moving cutting knife (s) attached to the razor. Frictional forces should be reduced as much as possible.

30 9807/0865

In those cases where a moving cutting knife is intended to carry out its movement along a substantially rectilinear path, as is usually the case with the known types of Razors is required, the bearings or the support structure should guide the cutting knife along a path as rectilinear as is possible.

To achieve the above goals, among other things, was already in the British Patent No. 1 129 556 proposed to mount the cutting knives on a pair of spaced apart resilient plates having three coplanar legs, which are connected at their lower ends. The free ends of the two outer legs are attached to the razor body, while the free end of the middle leg is attached to a frame that carries the cutting knife. With this proposal however, the other end of each resilient body where the legs are connected may freely vibrate in correspondence with the cutting knife and, as a result, may develop large amplitudes of vibration. This is disadvantageous because it does the stability of the reciprocating movement of the cutting knife is impaired and undesirable on the razor body Vibration is transmitted and also an undesirable noise is generated.

In the known construction, which works with elastic bodies, which have several legs, but no web, who is held, it has now been found that the common end or lower end of the leg, which is neither at the body of the razor is still attached to the movable cutting blade, tends to have a very large amplitude of vibration to generate, which is even larger than that of the cutting knife itself. This oscillation amplitude is from the above However, reasons are undesirable and should, according to the present object of the invention, be significantly reduced. The lower

309807/0865

Ends of the legs vibrate with an amplitude that is considerable is smaller than that of the cutting knife itself.

According to the invention, a dry razor is now created, which has a cutting knife, which along a substantially linear path is moved back and forth with the aid of at least two resilient bodies, these bodies being approximately perpendicular extend to said web and each elastic body has a web and at least two legs that of the one end of the web are directed away from which they form a continuation · The free end of at least one leg is attached to the cutting knife, while the free end of the web against vibration in the direction parallel to the The trajectory of the reciprocating cutting knife is held.

The invention therefore does not relate to the exact training of the cutting head of a dry razor, but rather deals

Oil YYY

with the cutting head type, that of a stationary outer, perforated and consists of curved foil and an inner cutting knife that has multiple blades mounted on a support are attached and are profiled so that they adapt to the curvature of the outer film, the inner cutting knife executes an oscillating movement along a substantially rectilinear path parallel to the axis of curvature of the film.

Another advantage that results from the use of resilient bodies with several adjacent legs, can be seen in the fact that the legs are arranged in this way can that they guide the cutting knife along a very precisely linear path. Thus, the free end of the web becomes preferable held by a device that the web a limited freedom of movement in the direction perpendicular to the movement path of the Cutting knife granted. Such a retaining device has

3 0 9 H 0 7/0 8 65

it is best to open elements made of resilient material, one of which is located on each side of the bridge, completely generally opposite to the direction of travel of the cutting knife, and mounted on a fixed part of the dry razor. Alternatively, the retaining device can be a leaf spring, which is located between the web and a fixed portion of the dry shaver extending across the ridge.

According to an embodiment which will be described below, each resilient body has three coplanar legs, wherein the free ends of the central leg are mounted on a fixed part of the razor, and the cutting knife is mounted on the free ends of the two outer legs.

Each resilient body is preferably in the form of a resilient plate which is provided with three legs. the The plate can be made of metal and each leg can be replaced by an upturned flange along the one or more Thigh edges be stiffened. Furthermore, by forming an upturned flange along the outer edge of each outer leg and continues along the edge of the web, it must be ensured that the The cutting knife and the leg carrying the web bend together.

Due to the resilient or elastic attachment, the cutting knife has a natural oscillation frequency, at which swings the cutting knife along the linear path. Preferably means are provided which operate so that they drive the cutting knife at or near this resonance frequency. It is understood, however, that the minor Friction and the linear movement, as achieved by the invention, can also be obtained without resonance operation

309807/0865

can, and that in certain cases it can be advantageous to operate the drive device at a frequency which deviates from the resonance frequency, but to the material frequency is in a selected relationship.

The dry razor can also have one or more counterweights in the vicinity of the cutting knife, which along an im essentially linear path, which runs approximately parallel to that of the cutting knife, can swing and from a support structure which is similar to that of the vibratable cutting knife, the device to drive the cutting knife can also be used to drive the counterweights, namely anti-cyclically, that is out of phase with the cutting knife. This arrangement reduces significantly reduce the vibrations that are otherwise caused by the mass of the oscillating cutting knife.

Have the counterweight or counterweights arranged as close as possible to the moving cutting knife proved to be advantageous ^ because it allows the small vibratory motion that occurs when the mass or the Masses of the counterweights oscillate along different axes out of phase, is kept to a minimum.

Alternatively, a two-part cutting knife can be used, the two cutting knife parts correspondingly driven out of phase. The construction supporting the cutting knife or the cutting knife part and / or the structure supporting the counterweight is preferred provided with two resilient bodies that point in the direction of the movement of the cutting knife and / or the counterweight are at a distance from each other.

The exact type of drive device or power source used is not important, but in

309807/0865

those cases in which resonance is required and the dry shaver is to be operated on an AC mains
AC synchronous motor can be used · This motor runs continuously at a constant speed, which is determined by the mains frequency, so that it is able to use the resonance system
To drive the cutting knife and counterweight at resonant frequency using a cam arrangement such as that described below, provided the elements are tuned to move at the correct frequency
are in resonance.

Alternatively, a DC rotor motor can be used, which is either fed from batteries located in the dry shaver housing, or from a rectifier circuit that is fed from the mains. Constant speed is relatively easy to obtain in a DC motor by using a back EMF bridge in conjunction with a voltage control amplifier system. Alternatively, a servo system can also be used in which a
The tachometer generator is driven by the motor and its output voltage, which is proportional to the motor speed, is compared to a reference voltage to generate an error signal to control the motor input current. If the engine is running at a constant speed in this way and resonance operation is required, it is only necessary to arrange the resonance system or systems of the dry shaver to match the speed of the engine. This can initially be done by approximation, with a variable
Can be used element that is installed in such a way that the engine speed can be varied over a range and can be set manually / within the range to resonate the
system consisting of a cutting knife and / or counterweight
to achieve."

309807/0865

Here, too, it is possible to use driven devices in the form of a vibrator motor, which has a two-part reaction system consisting of a permanent magnet and a coil which can be supplied with current in order to oscillate one part of the system relative to the other produce.

The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing. In the drawing show:

Fig. 1 is a cross-sectional view along the line I-I

in Fig. 2, from which the main parts of the electrical

Dry razor can be seen, Fig. 2 is a cross-sectional view along the line II-II

in Fig. i,
3 shows a resilient body of the one shown in FIGS. 1 and 2

shown dry shaver, nraö Fig. 4 is an illustration of the operation of a Üeöernd

suspended system as shown in Figs

will be shown.

In Fig. 1 at 1 is an inner, movable cutting knife of the dry shaver shown. This inner cutting knife naturally belongs to a stationary outer cutting knife, the one perforated film can be, since this part is not essential to the invention it is not shown here, as is the surrounding housing with which the razor is normally provided is.

The cutting knife 1 should be along a substantially swing linear path in the direction of its length.

The cutting knife 1 is mounted on a cutting knife support structure worn, to which an aging block 2 belongs,

3.0 S H f i 7 / Ü 8 8 5

on which the cutting knife 1 is attached, possibly with a resilient element, for example one or more springs or rubber, interposed. The mounting block 2 is attached directly to a bridge 3 which is fork-shaped at both ends in the same way as the bridge 3a, which can be seen in FIG. 2 and will be described later. The two downwardly projecting parts at the left end of the bridge 3 are rigidly attached to the upper ends of the two outer legs h and 5 (see FIG. 3) of a resilient body 6, for example by rivets. The resilient body 6 is shown in perspective in FIG. 3, while FIG. 1 shows it in longitudinal section. A cross-sectional view of the resilient body 6 is shown in FIG. 2.

The resilient body 6 extends approximately perpendicular to the oscillation path of the cutting knife 1. A third and middle leg 7 of the resilient body 6 is located between the legs 4 and 5 'and the upper end of the leg is attached, for example, by rivets or screws to a fixed part 8 of the razor. The fixed part 8 can be in the form of a base that holds the working parts of the razor within a suitable housing.

Fig. 1 shows one side of the construction completely, which is, however, symmetrical in practice, so that the left Side of the construction, as can be seen in Fig. 1, is also present in a mirror image on the right-hand side. Thus becomes the cutting knife 1 carried in the razor with the help of two resilient bodies 6, one of which is located at the end of the bridge is located.

A pair of counterweights 9 1st on the bridge 3a, which is the Bridge 3 is similar, but shorter than this, firmly attached, and the bridge 3a is at its ends by two resilient Body 6a carried, of which only the left one can be seen in FIG.

309807/0865

These resilient bodies 6a are generally similar to resilient body 6 in terms of their shape.

In Figures 1 and 2 it is shown that the central leg of the resilient body 6a, which is denoted by 7a, is attached to the fixed part 8 of the razor. The two outer legs ha. And 5a are attached to the two downwardly directed parts 10a at the end of the bridge 3a.

The resilient body 6 and 6a are of the same length, but the body 6 are arranged slightly higher than the body 6a, so that the bridge 3 lies over the bridge 3a. The counterweights 9 lie between the two bridges and are thus quite close to the movable cutting knife 1 located. -

As can be seen from Fig. 3, the resilient body 6 has a web which extends from the lower ends of the three legs 4, 5 and 7 away in the opposite direction of these legs and is denoted by 11. From Fig. 1 it can be seen that the web 11 at a point from the lower ends the leg is remote, with the aid of prism-shaped plates 12 made of deformable material, for example soft Rubber, which blocks are attached to plates 13, which in turn are attached to part 14 of the razor are in firm connection. A corresponding extension 11a of the resilient body 6a becomes deformable in a similar manner Blocks 12a held, one on the middle plate 13 and the other on another plate 13a is appropriate.

FIG. H shows schematically the bridge 3 and its supporting structure, to which two resilient bodies 6 belong. The bodies 6 are shown in their central position in full lines, and they also assume this position in FIG. 1,

309807/0865

223629?

while the positions shown in broken lines are shifted to either side of the middle position. When the bridge 3 is moved from its central position to one side or the other, the firmly attached middle legs 7 of the body 6 are bent out of the plane of the body 6, while the outer legs k and 5 and the webs 11 bend together and approximately stay in the same plane

The type of suspension shown in Fig. K can be designed so that a precisely linear path for the displacement of the bridge 3 is achieved. The fact that the parts 8 to which the middle legs 7 are firmly attached cannot be in the same plane as the bridge 3 can be compensated for by a suitable selection of the bending properties of the middle leg in connection with the two outer legs h and 5 .

When the bridge 3 lengthways from one side to the other its linear path is moved, then the lower end of the web 11 moves slightly in each resilient body Direction perpendicular to the bridge 3. This movement is made possible by the deformability of the retaining blocks 12, while uncontrolled oscillations of the web 11 in a parallel direction to bridge 3 can be prevented. Due to the elasticity or the resilience of the body 6, the cutting knife 1, the bridge 3 and the body 6 themselves have a natural frequency in which they perform resonance vibrations, the cutting knife oscillates along a linear path parallel to that of the bridge 3. The frequency is determined by the mass of the cutting knife 1 and the bridge 3 and the stiffness of the resilient Body 6.

- 11 -

309807/0865

The body 6 can be made of thin sheet metal, which consists for example of a copper / beryllium alloy or steel. In order to increase the natural frequency in the embodiment described, the bodies 6 are stiffened, and this prevents undesired vibrations. This is done with the help of upwardly turned flanges 17 along the two side edges of the middle leg 7 and also upwardly turned flanges 18, which run along the outer edge of each of the outer legs h and 5 and continue along the outer edges of the web 11. Besides the fact that they make the body 6 more rigid, the flanges 18 also ensure that the web 11 and the outer legs h and 5 bend together and that the middle leg 7 bends separately therefrom. This is important because if the middle leg 7 and the web 11 were stiffened so that they would form a unit, for example with the help of a single central stiffening body, these parts would then remain essentially straightened when the bridge 3 of the one side to the other swings, since then both the middle leg 7 and the web 11 would be fixed or would be held. Then the legs h and 5 would simply bend from side to side, approximately around the center of the body 6, and their upper ends would perform an arcuate movement which would have a small undesirable component perpendicular to the bridge 3.

The bridge 3a, which carries the counterweights 9, can in in the same way as the bridge 3 oscillates on its resilient bodies 6a carrying it, as is the case with reference to FIG. 4 was shown. The mass of the counterweights 9 is chosen so that when the weights are out of phase with the cutting knife 1 and vibrate parallel to it, the resulting vibration is essentially zero «, the natural or natural frequency of the Counterweights 9 on their supporting structure can be balanced. become that it is equal to that of the cutting knife 1.

0 9 8 0 7/0865

This can be done by suitable selection or adjustment of the stiffness of the resilient bodies 6a in relation to the mass the counterweights 9 and bridge 5a happen.

In the illustrated embodiment, the flanges 17a extend slightly further on the body 6a upward than the flanges 18a, the upper end being shown in broken lines in FIG.

Zn Fig. 1, the drive device for the cutting knife i is shown in the form of an electric motor 19, the is mounted on a fixed part 20 of the razor. The drive shaft 21 of the motor runs through corresponding openings 22 and 22a in bridge 3 and bridge 3a, and Within these openings, eccentric cams 23 and 25a are attached to the shaft 21. The cams 23 and 23a are offset by 180 ° from each other, so that when the motor 19 rotates, the bridges 3 and 3a are caused to swing out of phase along their orbits, whereby the desired vibration-free operation is created «

This can also happen if the motor 19 is not running at such a speed as is necessary for the Drive cutting knife 1 and the counterweights 9 at their resonance frequency.

To these parts, however, at their natural frequency and thus To drive resonance frequency or a frequency approaching this frequency, the motor 19 must be set to the appropriate Speed can be controlled. A control circuit that to achieve this control in a DC motor has already been mentioned and such a circuit is known per se. It is therefore not described in detail in the following described.

309807/0865

The bridges 3 and 3a also knew alternatively by one Vibrator motor are driven, which has a two-part reaction system, consisting of a permanent magnet and a Coils that are supplied with alternating current or a series of current pulses taken from a battery. The magnet can on one bridge and the coil on the other bridge.

It is understood that. 3 k, the two outer leg when using the three-armed resilient body of Figure and may be attached to the fixed parts of the shaver, while the bridge could be worn 3 on the center leg 7. In this case, if a stiffening of the resilient body were necessary, this would be done by a reinforcement that extends along the middle leg 7 and the web 11, as well as by a separate reinforcement of the two legs k and 5 'so that the latter are from the general plane of the resilient element can bend.

The resilient elements or bodies could, however, also be made from metal wire or from a suitable plastic material as is evident to the person skilled in the art, and they could also be inseparably connected to the bridges 3 and 3a.

The resilient bodies, as shown in FIGS. 1 to 3 it can be seen that the movement of the cutting knife and also of the counterweight, if one is present, takes place very precisely linearly, with very little friction and, at the same time, essentially unwanted vibration eliminating the problem that occurs when no pinned web is provided. This form of the cutting knife part or supporting structure is also immune to problems that would otherwise arise from dust and dirt entering the razor can.

309807 / 086ß

22362Sf

The use of one or more counterweights that vibrating out of phase with the cutting blade also helps achieve low vibration when the razor is operating. An operation of the cutting knife and also of the counterweight, if one is present, results in the resonance range, as was found to lead to a reduction in energy consumption.

Instead of the counterweight, the cutting knife could be designed in two parts, for example in the longitudinal direction be slotted, and the two cutting knife parts could then move back and forth out of phase

A feature of the resilient support bodies described above is that these bodies fulfill combined functions, namely a carrying or supporting function, a guiding function along an essentially linear path and finally a spring load in the direction of the rest position

The term "out of phase" used in the above is intended to mean that the relevant parts are in opposite directions Move phase.

309807/0865

Claims (1)

PATENT CLAIMS 1J dry razor with a cutting knife along a m essentially linear path with the help of two resilient bodies which extend approximately perpendicular to this path, is guided to and fro, characterized in that each resilient body (6, 6a) has a web (il) and at least two legs (4, 5 »7), which from one end of the Stand out web and form a continuation of the web that the free end of at least one leg (4, 5 »7) is attached to the cutting knife (i), and that the free end at least another leg is attached to a fixed part of the razor, while the free end of the web (il) against Vibration in the direction parallel to the path of the reciprocating movement of the cutting knife (l) is arrestable. 2. Dry razor according to claim 1, characterized in that the free end of the web (li) with the aid of a device can be retained, which gives the web a limited freedom of movement in the direction perpendicular to the path of movement of the cutting knife granted. 3. Dry razor according to claim 2, characterized in that the holding device consists of elements (12), oils are made of resilient material and one of which is located on each side of the web (il), opposite to the direction of movement of the cutting knife (i), and on a fixed part (13, 13a, 14) of the razor is appropriate. k » Dry razor according to one of Claims 1 to 3», characterized in that each resilient body (6, 6a) has three legs (** »5, 7) which are coplanar in the natural rest position of the body. 3 0 9 8 0 7/0865 5 * dry razor according to claim 4, characterized in that the middle leg (7) is attached to a fixed part (θ) of the razor, and that the two outer legs (k, 5) are attached to the cutting knife (l). 6, dry razor according to one of claims 1 to 5 »thereby characterized in that each resilient body (6, 6a) is in the form of a flat plate. 7. Dry razor according to claim 6, characterized in that each leg (4, 5, 7) is stiffened in the longitudinal direction β. The dry shaver as claimed in claim 7 »that di6 ⁿ longitudinal direction by means of a known stiffening is achieved upturned flange (17, 18). 9 · Dry razor according to claim 8, characterized in that that the plate (6, 6a) is provided with upturned flanges (18) extending along the outer edges of the outer Legs (4, 5) extend and continue along the outer edges of the web (II). 10. Dry razor according to one of claims 1 to 9, characterized in that the cutting knife (l) is the inner The cutting knife of a razor is provided with an outer shaving foil. 11. Dry razor according to one of claims 1 to 10, characterized by a drive device (19) for moving the cutting knife (1) back and forth at a frequency, the natural frequency of the back and forth movement of the cutting knife, which is provided by its resilient holder, is in a chosen relationship. 309807/0865 12. Dry razor according to claim 11, characterized in that that the drive device (19) works in such a way that it moves the cutting knife (1) back and forth at a substantially natural frequency moved here. 13. Dry razor according to one of claims 1 to 12, characterized characterized in that the cutting knife (l) is formed from two parts that are reciprocable out of phase, and that each cutting knife part is fastened with the aid of at least two resilient bodies (6, 6a). lh. Dry razor according to one of Claims 1 to 13 », characterized in that the razor has a counterweight (9) which can be moved back and forth out of phase with the cutting knife (1) and is fastened with the aid of at least one resilient body (6, 6a) . 15 dry razor according to one of claims 1 to 14, characterized in that the cutting knife (l), the cutting knife parts and / or the counterweight (s) (9) are each held by two resilient bodies (6, 6a) which are spaced in the direction the path of movement of the cutting knife carried by them, the cutting knife parts and / or the counterweight next to one another lie. 16. Dry razor according to one of claims 1 to 15, characterized by a drive device (19) in the form of a rotating motor, which causes the desired back and forth movement by interposing a cam (23, 23a). 17. Dry razor according to one of claims 1 to 15, characterized by a drive device in the form of a vibrator motor, which has a two-part reaction system that consists of consists of a permanent magnet and a coil, which can be supplied with current, in order to induce a movement of one part of the System in relation to the other. 309807/0865