Electric shaving apparatus

An electric-powered shaving apparatus with a drive part excitable by an electric motor into performing an oscillatory motion, the drive part transmitting its motion for cutting hairs to a short-hair cutter and to a long-hair trimmer. The long-hair trimmer is displaceable relative to the housing into an advanced and a retracted position. The motion of the drive part for the short-hair cutter is utilized for moving the long-hair trimmer into the advanced position.

TECHNICAL FIELD

This document relates to an electric shaving apparatus.

BACKGROUND

An electric-powered shaving apparatus having an undercutter reciprocating underneath a shaving foil is known from German Patent No. DE 195 31 013 C 1. In this shaving apparatus, which shaves either with or without moisture, the short-hair cutter unit is driven by a first electric motor. To pop up the long-hair trimmer unit, this shaving apparatus uses another electric motor with a gearing. This motor, upon being turned on, drives the gearing, thereby moving the long-hair trimmer from its home position into its advanced position. Since movement of the long-hair trimmer is effected just by touching an electric switch, this arrangement presents a comfortable handling solution for an electric shaving apparatus.

SUMMARY

One aspect of the present invention is an electric-powered shaving apparatus having a drive part excitable by an electric motor into performing an oscillatory motion. The drive part transmits its motion for cutting hairs to a short-hair cutter on the one hand and to a long-hair trimmer on the other hand. The long-hair trimmer is displaceable relative to the housing into an advanced and a retracted position, utilizing the motion of the drive part for moving the long-hair trimmer into the advanced position. The shaving apparatus has a cutter block that is adapted to reciprocate along a shaving foil and that is driven by the oscillatory motion of the drive part connected to the an electric motor, the shaving apparatus makes use of this particular motion for driving a long-hair trimmer integrated in the shaving apparatus. Therefore, there is no need to provide an additional drive motor for popping up the long-hair trimmer.

The coupling of the pop-up device of the long-hair trimmer to the drive part of the shaving apparatus can be accomplished either within the housing or, in some embodiments, on the portion protruding from the housing, which conventionally is part of an oscillatory bridge. In the latter embodiment, an additional sealing is avoided because both the coupling of the pop-up device to the oscillatory drive part and the long-hair trimmer itself are generally arranged outside the housing of the shaving apparatus.

For moving the long-hair trimmer into the advanced position, a motion-converting mechanism is provided between the drive part and the long-hair trimmer to divert the oscillatory motion into the direction of displacement (X) of the long-hair trimmer. The oscillatory motion of the drive part is converted in the motion-converting mechanism into an equally oscillatory motion which takes place in the direction of displacement of the long-hair trimmer. Typically, the oscillatory motion of the drive part takes place in the same direction as the motion of the cutter block of the short-hair cutter and as the motion of the undercutter of the long-hair trimmer. Considering that displacement of the long-hair trimmer into its advanced position is precisely perpendicular to the oscillatory motion of the drive part, it is necessary to divert this motion into this direction by means of a motion-converting mechanism. It is only then that this motion can be transferred to the long-hair trimmer to effect its displacement.

At the output of the motion-converting mechanism, provision is made for a strip movable in the direction of displacement (X). A first ratchet-and-pawl mechanism is provided between the strip and the long-hair trimmer. The first ratchet-and-pawl mechanism has a movable pawl on the long-hair trimmer and a toothed construction on the strip. The toothed construction is movable into meshing engagement with the pawl for advancing the long-hair trimmer. This establishes a connection between the output of the motion-converting mechanism and the long-hair trimmer by selecting a releasable engagement device in the form of the pawl provided on the long-hair trimmer and the toothed construction provided on the output for locking engagement by the pawl when the long-hair trimmer is engaged, the pawl thereby taking along the long-hair trimmer, step by step, to its advanced position in accordance with the converted oscillatory motion. The taking along in steps is attributable to the fact that, owing to the oscillatory motion, only a small oscillatory motion in the diverted direction of projection of the long-hair trimmer takes place, while movement in the opposite direction is not transmitted to the long-hair trimmer because of slippage, as in a ratchet. Equivalent solutions are also applicable, for example the pawl and the toothed construction can be interchanged.

Since the oscillatory motions in electric-powered dry shavers are relatively high in order to obtain a good cutting result, the movement of the long-hair trimmer to its end position is also fast. This can be further enhanced, in some embodiments, by selecting a correspondingly high transmission ratio in the motion-converting mechanism. The engagement of the pawl with the toothed construction at the output of the motion-converting mechanism can take place either mechanically by hand, or electrically by means of a solenoid-operated switch or similar devices.

Following latching engagement of the pawl with the toothed construction, a retaining device is provided that permits release of the first ratchet-and-pawl mechanism only when the long-hair trimmer is in the maximum advanced position. This means that when the ratchet-and-pawl mechanism is engaged mechanically, with the shaver turned on and the long-hair trimmer in the home position, it continues to be engaged until the long-hair trimmer has reached its maximum position. Only in the maximum advanced position of the long-hair trimmer can the pawl disengage itself from the toothed construction at the output. A guide rib for the pawl is interrupted at the upper stop, enabling an accurate position of the long-hair trimmer. On completion of the shaving operation, the long-hair trimmer can be pushed back to its home position by releasing the retaining elements.

In some embodiments, the retaining elements have a rib-and-groove arrangement extending in the direction of displacement of the long-hair trimmer. In this arrangement, the rib may be formed either on the pawl or on the housing of the shaving apparatus. Correspondingly, the groove is then provided on the respective other part. A dovetail guideway, or similar guiding devices, can also be used.

A second ratchet-and-pawl mechanism acts between the long-hair trimmer and the housing of the shaving apparatus, and the second ratchet-and-pawl mechanism inhibits displacement of the long-hair trimmer in the direction opposite the pop-up direction, ensuring a secure seat of the long-hair trimmer after it has reached its maximum advanced position. The second ratchet-and-pawl mechanism acts as a retaining device to prevent displacement of the long-hair trimmer towards its home position. The long-hair trimmer is only released when this second ratchet-and-pawl mechanism is disengaged mechanically by hand or by electrical devices.

The second ratchet-and-pawl mechanism has of a lever fastened to the housing and resiliently engaging in a longitudinal toothed construction provided on the long-hair trimmer. In some embodiments, a detent lever cooperating with a toothed construction can been used as second ratchet-and-pawl mechanism, with the detent lever being mounted for rotation on the housing and resiliently engaging the toothed construction formed on the long-hair trimmer, so as to inhibit movement of the long-hair trimmer in the direction of its home position. Only after the detent lever of the second ratchet-and-pawl mechanism is mechanically unlatched from the toothed construction is it possible for the long-hair trimmer to be shifted back to its home position.

In some embodiments, the long-hair trimmer is biased against the pop-up direction by a spring element. The long-hair trimmer is automatically returned to its home position by the force of the spring following unlatching of the second ratchet-and-pawl mechanism.

The first and the second ratchet-and-pawl mechanism are adapted to latch and unlatch manually by means of a control element. This results in a simple mechanical latching/unlatching arrangement which is actuatable by hand. A particularly low-cost arrangement can be achieved with a tandem lever which, on being turned in the one direction, causes the first ratchet-and-pawl mechanism to be latched and, on being turned in the other direction, causes the second ratchet-and-pawl mechanism to be unlatched.

DETAILED DESCRIPTION

FIG. 1shows an electric-powered shaving apparatus1conventionally designated as a dry shaver, having a housing2and a shaving head3adjoining the upper part of the housing2. The shaving head3may be fixedly or pivotally mounted in the housing2and it has an upwardly open aperture4with two upwardly arched shaving foils5,6integrated therein. The undersurface of the two shaving foils5,6is engaged by two cutter blocks (not shown) arranged side-by-side and connected with each other, which are excitable by a drive part22, as shown inFIGS. 2 to 5, into performing an oscillatory, that is, reciprocating motion Y. In some embodiments, the drive part22is connected to a rotary electric motor (not shown) received in the housing2through an eccentric gearing (not illustrated in the drawing). For generation of the oscillatory motion, an oscillating armature motor or some other electric drive can be used.

Provided on the front side of the housing2inFIG. 1is a long-hair trimmer8, which has a stationary outer cutter9and an undercutter10slidably engaging the undersurface of the outer cutter9, and performing reciprocating motions in the direction Y when in operation. The long-hair trimmer8combines with its front panel12and with the mechanical pop-up device14, disposed behind the front wall13(FIG. 1) and as schematically shown inFIGS. 2 to 5, to form the long-hair trimmer unit. InFIG. 1the long-hair trimmer8is guided on its sides in opposite lying lateral grooves15for up and down movement in the direction X, as shown inFIGS. 1,2and3.

FIGS. 2 to 5show an embodiment of pop-up device14reflecting the basic structure of the pop-up device14. Thus, in the embodiment shown inFIGS. 2 through 5, the housing2has flanged to it a provisional backing plate19. Two guide pins18are fixedly secured to the provisional backing plate19, vertically one above the other in the direction of displacement X of the long-hair trimmer8. The pins extend through respective longitudinal slots17. The slots17are formed in a support slide16equally in the direction of displacement of the long-hair trimmer8for relative sliding movement with snug lateral fit. As a result, the support slide16is guided in the longitudinal slots17only in the up and down direction of displacement X. In other embodiments, other guide arrangements17,18may be substituted for the guide arrangement shown, including for example a dovetail, a coulisse, a rail, a drawer guideway etc., provided that the direction of displacement X, which is perpendicular to the orientation of the outer cutter9and undercutter10and also perpendicular to the movement Y of the undercutter10, of the long-hair trimmer8is accurately maintained, and that the support slide16moves also parallel to the housing2.

Secured to the support slide16is the long-hair trimmer8, as indicated inFIGS. 2 to 5by the broken line20. In some embodiments, the support slide16and the long-hair trimmer8can be combined into a single plastic component. At this point it is further noted that like components shown inFIGS. 2 to 5are assigned like reference characters even if not expressly referred to in each Figure, accordingly also functioning in like manner.

Formed in the backing plate19, inFIGS. 2 to 5, is a substantially rectangular cutout21into which the drive part22, which is connected with an electric motor (not shown), extends from the interior of the housing2. The drive part is connected to a bell crank lever24through a claw coupling23provided on the lever. The claw coupling23is of a substantially fork-shaped configuration having a slot25, which is engaged by the drive part22constructed as a peg. Through a journal26secured to the backing plate19, the bell crank lever24is mounted for pivotal movement about the journal in the range of the oscillatory motion Y. The bell crank lever24is arranged in front of the backing plate19.

Level with the journal26, and on its right-hand side when viewingFIGS. 2 to 5, an angle member27extends away from the bell crank lever24. The angle member has a horizontally extending longitudinal bore28engaged by a roll-type driving element29, which in turn is fixedly connected with a strip31secured to the backing plate19by screws30. The strip31extends in the direction of displacement X, and has on its right-hand side a toothed construction32running along the strip31from below to above. Above and below the angle member27, the strip31is provided with slots33penetrated by screws30sized to fit snugly laterally, thereby producing a slide guide for the strip31in the direction X. Both the guide pins18and the screws30have their ends enlarged to maintain the parts16,31at a constant distance parallel to the housing2. The bell crank lever24and the strip31provide a motion-converting mechanism34which translates the horizontal reciprocating motion in the direction Y to a vertical up-and-down motion in the direction X.

According toFIGS. 2 to 5, the toothed construction32is composed of a plurality of slightly upwardly slanting small teeth35disposed one above the other along the same line, their relative spacing being dimensioned so small that on each forward stroke of the strip31in the direction X at least one tooth can be skipped, hence feeding the strip31upwardly in the direction X.

According toFIGS. 2 to 5, rotatably mounted on the support slide16at a site level with the lower section of the toothed construction32is a hook-shaped pawl36, having its center of rotation37located on a projection38formed on the support slide16. The support slide16is essentially frame-shaped and has a quadrangular aperture39extending substantially parallel to the edge of the support slide16. InFIGS. 2 to 5, the center of rotation37of the pawl36lies to the right of the toothed construction32and below it on the support slide16. The pawl36and the support slide16have each a respective fastening lug40,41between which a biased extension spring42is held which ensures that the pawl36is turned clockwise about its center of rotation37. In the home position ofFIGS. 2,4and5, it abuts against the support slide16or the intermediate member60.

The pawl36has an angled arm43, whose free end44is designed for engagement with each individual tooth35from above, hooking into it on upward movement of the strip31(FIG. 3) such that the pawl36takes along the support slide16upwardly in the direction X. Provided on the side of the pawl36facing the backing plate19is a rib45extending in the direction X. The rib protrudes from the rear end of the pawl36, and is shown in broken lines inFIGS. 2 to 5, since it is not visible from the front. The rib45corresponds with a groove46formed in the backing plate19, that is, the groove46is in alignment with the rib only when the pawl36has reached the position shown inFIG. 3. In this position the pawl36connected with the support slide16is able to engage the groove46in its upward movement, so that the pawl36dwells in this position shown inFIG. 3while the upward movement continues, its tooth44hence resiliently engaging a tooth35on the toothed construction32.

The pawl36and the toothed strip31combine to form the first ratchet-and-pawl mechanism55. In the direction of upward movement X of the support slide16, the first ratchet-and-pawl mechanism55takes along the pawl and with it the long-hair trimmer8connected to the support slide16. In the direction of downward movement X, the first ratchet-and-pawl mechanism55slides over the teeth35owing to the resilient arm43, without taking along the support slide in downward direction, provided that the second ratchet-and-pawl mechanism54is in engagement. Explained in greater detail in the following description. The groove46extends likewise in the direction of displacement X, with the upper end of groove46corresponding to the end of upward travel of the support slide16connected with the long-hair trimmer8. In other embodiments, instead of providing the rib45on the pawl36, it also possible to provide the groove there, and instead of providing the groove46on the backing plate19it is also possible to provide the rib there in order to obtain the same effect of a coulisse guideway.

Furthermore, inFIGS. 2 to 5, a bolt47is fastened to the backing plate19below the center of rotation37. The bolt47serves as pivot point for another lever48. The upper free end of lever48terminates with a tooth49engaging from below within a toothed strip50provided on the support slide16, however only in the positions according toFIGS. 2 to 4. The teeth formed on the toothed strip50are directed downwardly. Upon meshing engagement of the tooth49with the toothed strip50, the support slide16ofFIG. 2can be displaced upwardly, but not downwardly in the direction X. For engagement of the lever48with the teeth50, an extension spring52acts against the end51opposite the tooth49and takes support upon a pin53secured to the backing plate19. The extension spring52is held biased between the pin53and the free end51of the lever48for resilient engagement with the toothed strip50. The lever48combines with the toothed strip50to form the second ratchet-and-pawl mechanism54, as mentioned above.

On the right-hand side ofFIGS. 2 to 5, a tandem lever57having an upper and a lower control element58,59is fastened to the backing plate19for pivotal movement about a center of rotation56. The upper control element58rests against an intermediate member60, which rests with its opposite end against an abutment surface61provided on the pawl36(FIG. 3). The intermediate member60is guided in a horizontal well62formed in the backing plate19. Acting against the intermediate member60is a spring63bearing with its other end against the backing plate19. The spring63serves to return the tandem lever57to its initial position shown inFIG. 2following its actuation according toFIG. 3.

According toFIGS. 2 and 4the lower control element59acts upon an intermediate member64, which is likewise horizontally guided in a well65formed in the backing plate19and whose end remote from the lower control element59is pivotally connected to the lever48through a pivot joint66. Upon actuation of the tandem lever57in clockwise direction according toFIG. 5, the lever48is turned counter-clockwise until its tooth49formed at its free end is disengaged from the teeth of the toothed strip50. As this occurs, the spring52is further biased.

The mode of operation of the automatic pop-up device for use in the shaving apparatus is as follows:

Starting from the home position ofFIG. 2, when wishing to cut off longer hairs, for example, beard hairs, the first step is to actuate an ON/OFF switch (not shown) provided on the shaving apparatus to start its electric motor (not shown). Then, the tandem lever57can be actuated by pivoting it about its center of rotation56to cause the long-hair trimmer8to move out of the housing2automatically. Starting the electric motor sets the drive part22in an oscillatory motion in accordance with the direction of displacement Y. The amount of excursion of the drive part22to the left and likewise to the right depends on the design of the gearing (not shown) provided between the electric motor and the drive part22or on the excursion of the oscillating armature motor.

In executing the oscillatory motion in the direction Y, the drive part22takes along the claw coupling23such that the bell crank lever24swings forward and backward about the journal26using a swinging motion X′. Simultaneously with the swinging motion X′, the angle member27moves also, taking along the driving element29of the strip31correspondingly. As this occurs, the strip31is caused to oscillate only in the direction X upwards and downwards because, by virtue of the longitudinal bore28, motions are transmitted to the strip31only in vertical and not in horizontal direction according toFIG. 2, hence producing a pure up-and-down motion in the direction X, which is transmitted via the driving element29to the strip31. A contributing factor is also the coulisse guideway33, which permits only a movement of the strip31in the direction X.

The connection between the drive part22for the long-hair trimmer8and the electric motor is established through a coupling member (not shown) when the tandem lever57is actuated, causing the long-hair trimmer8to be moved upwards in the direction X a small amount. This serves to prevent the long-hair trimmer from constantly running along with the short-hair cutter during a normal shaving operation which, apart from louder noise and increased energy consumption of the shaving apparatus, would necessarily subject the long-hair trimmer8to faster wear.

When it is desired to activate the long-hair trimmer8in addition to the short-hair cutter11, an operator (not shown) moves with his finger67the upper control element58of the tandem lever57in accordance withFIG. 3, such as to cause the control element58to displace the intermediate member60to the left into the well62. As a result, the pawl36is rotated counter- clockwise about the center of rotation37against the force of the spring42. The free end44of the pawl36then meshes with the toothed construction32, as shown inFIG. 3. Since the strip31moves up and down in the direction X, it is only during the upward movement that the pawl36, and with it the support slide16with the long-hair trimmer8, is moved upwardly by the resilient meshing engagement. As the tooth49of the lever48is in direct meshing engagement with the toothed strip50only when the strip31moves upwardly, the downward movement of the strip31causes the tooth44to slide over one or more teeth35of the toothed construction32, and this is so because the meshing engagement is of the ratchet type and because during the downward movement the second ratchet-and-pawl mechanism54inhibits a displacement of the support slide16in downward direction.

On initial displacement of the support slide16upwards in the direction X, the rib45is aligned with the groove46as a result of the actuated position of the tandem lever57and the resulting counter-clockwise rotation of the pawl36into its engaged position ofFIG. 3. Upon further displacement, the rib45engages within the groove46, causing the pawl36to dwell in the position shown inFIG. 3to thereby ensure meshing engagement of the free end44of the pawl36with the toothed construction35without the need for continued operation of the tandem lever57. Therefore, with the long-hair trimmer8continuing to move upwardly, actuation of the tandem lever57can be terminated, so that it returns automatically to its initial position shown inFIG. 2, without the pawl36sliding out of the groove-and-rib arrangement46,45again.

Each upward movement X of the strip31is followed by the downward return movement X, the free end44then sliding over one or several teeth35ratchet-like, because at the same time the second ratchet-and-pawl mechanism54prevents movement of the support slide16downward in the direction X. In the return stroke of the strip31the support slide16and hence the long-hair trimmer8dwell in this position. Upon the next upward stroke of the strip31, the process previously described is repeated.

The long-hair trimmer8is not activated until it has been moved upward a small amount in the direction X or at the latest before it has reached its maximum advanced position, and it remains activated until it has reached its home position ofFIG. 2again. Responsible for the oscillatory shearing motion is a sliding coupling member (not shown) which does not engage the drive part22until the long-hair trimmer8has left its home position for a greater or lesser length of its travel. In this manner, the support slide16, and with it the long-hair trimmer8, travels stepwise in accordance with the oscillatory motion up to the trimmer's upper maximum position without the need to perform this displacement manually. Giving the tandem lever an initial push is sufficient to cause the long-hair trimmer8to travel out of its shaver housing2automatically in the upward direction X.

In this condition, longer hairs, or sideburns, or a beard or other hairs can be cut without the need to further actuate or hold the long-hair trimmer8in position. The reason for this is that the second ratchet-and-pawl mechanism54retains the long-hair trimmer8in its maximum advanced position.

To terminate a long-hair trimming operation, an operator presses with his finger67down on the lower control element59of the tandem lever57as shown inFIG. 5, such that its end moves the intermediate member64to the left within the well65, thereby causing the lever48to be rotated counter-clockwise. As this occurs, the tooth49formed at the lever's free end moves away from the toothed strip50, thereby unlatching the second ratchet-and-pawl mechanism54. As shown inFIG. 5, by virtue of the biased extension spring68which has its one end mounted on the backing plate19through a bolt69, and its other end on the support slide16through a bolt70, the support slide is displaced downwards in the direction X, returning to its home position. In the process, the longitudinal slots17slide along the guide pins18, whereby the direction of displacement X of the support slide16is exactly maintained. To avoid canting of the support slide16, another guide device (not shown) may be provided on the right-hand side. Following its release, the tandem lever57returns to its initial position shown inFIG. 2. The lever48follows this movement, that is, it resumes the engaged position shown inFIG. 2because the extension spring52always biases the lever48clockwise.