Abstract:
The invention is directed to a dry shaving apparatus with an electric drive mechanism (A) provided in a housing ( 1 ) and a housing part (G) in which a removable frame (WR) equipped with at least one cutter element (S) is held by at least one detent mechanism (R), wherein upon release of the removable frame (WR) by the detent mechanism (R) the removable frame (WR) is movably held in a holding position by a retaining device (HV), wherein in said holding position provision is made for at least one distance (W, W 1 ) between a wall of the removable frame (WR) and a wall of the housing part (G), and the removable frame (WR) is adapted to be set in motion by the drive mechanism (A).

Description:
This is a continuation of International Application No. PCT/EP99/04447, pending, with an International filing date of Jun. 26, 1999. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a dry shaving apparatus. 
     DISCUSSION OF PRIOR ART 
     A dry shaving apparatus of the type initially referred to is known from printed specification EP 0 161 508 B1. A shaving foil acting as a cutter element is attached to the removable frame in arched form. The removable frame with the shaving foil is arranged between two end cheeks of a housing part and detachably held by a detent mechanism provided in the end walls. The housing part holding the removable frame may be constructed as a component part of the housing of the dry shaving apparatus or it may be a separate housing part adapted to be coupled to and decoupled from the housing of the dry shaving apparatus. 
     From EP 0 673 728 B1 a dry shaving apparatus with a housing part provided on the housing is known. Demountably held between the end walls of the housing part by two detent mechanisms is a removable frame equipped with two cutter elements in order to ensure both the replacement of a defective removable frame and the cleaning of the complete shaving head, in particular the hair dust collecting chamber formed by the inner walls of the removable frame and the walls of the housing part enclosed by the removable frame, including the cleaning of the cutter elements provided by means of suitable cleaning brushes. 
     BACKGROUND 
     In this known dry shaving apparatus it is necessary for the shaving head of the dry shaving apparatus to be disassembled into several parts. When these parts which include, for example, the removable frame, the undercutter, the coupling element and the housing part of the shaving head are placed down in a bathroom sink, scattered soiling by hair dust occurs. When the user turns the dry shaving apparatus on with the removable frame demounted but the undercutter engaged, dislodged hair dust will be distributed over a major area of the sink. 
     It is an object of the present invention to effect cleaning of the shaving head, meaning the hair dust collecting chamber formed by the housing part and the removable frame and also the cutter elements provided, in particular the cutter elements utilized as undercutters, in simple manner and with minimum effort. 
     SUMMARY OF THE INVENTION 
     According to the present invention a dry shaving apparatus of the invention affords plural advantages, including for example, that actuation of the actuating device initially disengages the removable frame from the housing part for the frame to be subsequently movably held in a holding position by a retaining device, in which position at least one distance is maintained between at least one wall of the removable frame and at least one wall of the housing part, so that both the movability of the removable frame and the falling out of hair dust from the hair dust collecting chamber are ensured by this distance. To be able to perform at any time, such as daily, a basic cleaning operation of the shaving head which involves the removal of hair dust clinging to the walls of the housing part, the walls of the removable frame and the cutter elements from the hair dust collecting chamber without having to detach the removable frame from the housing part, the invention provides for setting the removable frame in motion by operation of the electric drive mechanism when the removable frame is held in the holding position by the retaining device, so that it is through this movement of the removable frame and the drive elements setting the removable frame in motion that the hair dust clinging to the walls of the removable frame, the cutter elements and the walls of the housing part is dislodged or dislodged to the maximum possible extent for it to fall out of the distances formed, whereby the removal of hair dust from the hair dust collecting chamber is optimized. 
     Accordingly, the present invention ensures a basic cleaning of the shaving head without the need to take the shaving head apart as by detaching the removable frame and decoupling existing undercutters from drive elements, for subsequent cleaning of these parts manually using a brush or the like. The hair dust which, according to the invention, falls out of the hair dust collecting chamber through the distance produced between the removable frame and a wall of the housing part, concentrates on a small area, for example, in a sink, to be disposed of by means of water, whilst heretofore several places or areas of a sink have been subject to soiling by the placing down and cleaning of component parts with adhering hair dust. 
     In a further aspect of this embodiment of the invention, provision is made for the removable frame to be detachably held by the retaining device. This arrangement initially ensures the exchange or replacement of removable frames which have become defective in the course of use, in addition to enabling the heretofore usual cleaning operation of the hair dust collecting chamber to be accomplished, including the cleaning of existing cutter elements of the shaving head to the extent this should become necessary for any reasons. 
     In one embodiment of the invention, in the holding position of the removable frame provision is made for a distance between a wall of the housing central portion and a wall of at least one bar of the removable frame. A further embodiment is characterized in that in the holding position of the removable frame provision is made for a distance between an end wall of the removable frame and an end wall of the housing part. According to a preferred embodiment of the invention, the distance is producible by shaping adjacent walls of the housing part and of the removable frame differently. According to a further preferred embodiment of the invention, the distance is producible by constructing at least one wall of the housing part in wedge shape to ensure detachment of the removable frame from the housing part. In another embodiment of the invention, the distance is producible by constructing at least one wall of the housing part and an adjacent wall of the removable frame in wedge shape to ensure detachment of the removable frame from the housing part. In a further aspect of this embodiment, at least one end wall of the housing part is of a wedge-shaped configuration. In a further aspect of the last mentioned embodiment, at least one end wall of the removable frame is of a wedge-shaped configuration. In a preferred embodiment of the invention, at least one end wall of the removable frame and at least one end wall of the housing part are of a wedge-shaped configuration. It is an essential advantage of previously mentioned constructions of adjacent walls of the housing part and the removable frame that the distance required both for moving the removable frame in the holding position maintained by the retaining device and for the falling out of hair dust from the hair dust collecting chamber is producible simply and economically merely by suitably adapting the respective wall shapes of the housing part and the removable frame. 
     To dislodge the hair dust from the walls defining the hair dust collecting chamber and also from the cutter elements rapidly and efficiently, one embodiment of the invention provides for the electric drive mechanism to be adapted to be coupled via a coupling element to at least one cutter element and also, by means of cooperating retaining elements of the retaining device, to the removable frame. In this way it is ensured that operation of the electric drive mechanism transmits the driving motion to the removable frame, causing it to oscillate for dislodging the hair dust. 
     In a preferred embodiment of the present invention, the removable frame held by the retaining device is adapted to be set in motion by a drivable cutter element. 
     To enhance the cleaning effect, one embodiment of the invention makes provision for a stop on at least one end wall of the removable frame, said stop being acted upon in pulse fashion by a drivable cutter element. By means of this stop the movements of the cutter element are transmitted to the removable frame in a directionalized, pulse-type fashion. 
     In a further embodiment of the invention a stop is provided on at least one outer surface of the removable frame, said stop acting upon an end wall of the housing part in pulse fashion. With this arrangement the pulse-type impact of a cutter element on the removable frame is transmitted to the housing part, thereby enhancing the dislodging of hair dust from the walls of the housing part in advantageous manner. 
     In another embodiment of the invention provision is made for the retaining device to be formed of at least two retaining elements adapted to be coupled to each other. In a further aspect of this embodiment, one of the retaining elements is provided on a coupling element, and a further retaining element on a drivable cutter element. In a further aspect of this last-mentioned embodiment, the retaining element is provided on a coupling element of a movable cutter element. Preferably, this retaining element is of a fork-shaped shaped configuration. In another aspect of this embodiment of the invention, the fork arms of the retaining element are resilient. Preferably, in the area of the opening of the fork arms provision is made for retaining beads reducing the width of the fork opening. One significant advantage of such a construction of cooperating retaining elements resides first in the simplicity of construction, considering that the retaining elements are formed on anyway necessary components of the dry shaving apparatus. The area between the resilient fork arms ensures the movement of the removable frame necessary for cleaning the shaving head and, in addition, the formation of a distance between removable frame and housing part. 
     A substantial advantage of the invention resides in that the movement of the removable frame, which is necessary to perform the cleaning function, is effected by a cutter element which, with the removable frame and the housing part in locked condition, is required to perform another function, namely the cutting of hairs. In a preferred embodiment of the invention, the cutter element is constructed as the undercutter of a short hair cutter unit. In an alternative embodiment, the cutter element is constructed as the undercutter of a long hair cutter unit. 
     Further advantageous arrangements relating to the design of coupling elements and the detent mechanism detachably holding the removable frame on the housing part will become apparent from the following description. 
     Embodiments of the present invention will be described in more detail in the following with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE INVENTION 
     FIG. 1 is a front view of a dry shaving apparatus with a shaving head arranged on a housing and comprising a housing part and a removable frame with cutter element; 
     FIG. 2 is a view of the upper part of the housing of a dry shaving apparatus having arranged above it a shaving head with a removable frame shown locked with the housing part; 
     FIG. 3 is a view of the upper part of the housing of a dry shaving apparatus with a housing part arranged above it, but absent a removable frame; 
     FIG. 4 is a view of the upper part of the housing of a dry shaving apparatus with a shaving head arranged above it and a removable frame unlocked from the housing part, yet held in a holding position; 
     FIG. 5 is a perspective view of the removable frame in which a long hair cutter unit is provided between two outer cutters, attached in arched form, of a respective short hair cutter unit, and a sectional view of a bar, an undercutter and an end wall of the removable frame; 
     FIG. 6 is an exploded view of the coupling element, the undercutters coupled thereto and the removable frame, showing also a part sectional view of a bar and an end wall of the removable frame; 
     FIG. 7 is a sectional view of the housing part in the area of detent elements and of the detent notches provided in the removable frame; and 
     FIG. 8 is a cross-sectional view of the housing part and the removable frame, showing the removable frame in a position in which it is disengaged from the detent elements. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a dry shaving apparatus TR with a housing  1  having arranged in its front panel an actuating switch  2  and an adjustably mounted trimmer unit TS. Provided in the bottom wall of the housing  1  is a socket  3  for connection to a power supply cord. Seated on the housing  1  is a shaving head having detachably secured in its housing part G a removable frame WR comprising at least one cutter element S. The housing part G of the shaving head is coupled to the housing by means of two supporting elements  4  and  5 . Together with the housing part G the supporting elements  4  and  5  are mounted in the housing  1  for back-and-forth movement in the directions of arrow P. In another embodiment the supporting elements  4 ,  5  are immovably secured in or on the housing  1 . 
     FIG. 2 shows the upper part of the housing  1  having in its upper side  6  several apertures  7 ,  8 ,  9  for passage of the supporting elements  4  and  5  projecting from the housing and a drive pin  10  of an electric drive mechanism A arranged in the housing  1 . The drive pin  10  makes engagement with a groove  12  of a coupling element  11  for transmission of a drive motion reciprocating in the directions of arrow P to a cutter element S mounted for oscillatory motion in the housing part G via a coupling element K—see FIG.  3 . The housing part G is comprised of two opposed end walls  13 ,  14  and a housing central portion  15  carrying the end walls. Detachably held between the two end walls  13  and  14  by means of detent mechanisms R is a removable frame WR. The removable frame WR receives at least one cutter element S and/or one cutter unit comprised of two cooperating cutter elements. 
     In the embodiment of FIG. 2 the housing part G of the shaving head is mounted on the supporting elements  4  and  5  for pivotal movement about a pivot axis Z—Z. To this effect, the supporting elements  4  and  5  protrude into the interior of the end walls  13  and  14  to ensure pivotability of the shaving head in the area of the pivot axis Z—Z by means of a pivot bearing—not shown. In another embodiment the housing part G of the shaving head may be rigidly secured to the housing  1  of the dry shaving apparatus or it may be constructed as a component part of the housing—not shown. The supporting elements  4  and  5  are either rigidly secured in the housing  1  or, in an alternative embodiment, mounted for movement at least in the directions of arrow P. Provided on the housing part G are two pushbuttons  16 ,  17  which, when actuated, enable the removable frame WR to be unlocked for the purpose of detaching it. 
     FIG. 3 shows the upper part of the housing  1  with a housing part G disposed thereon but with the removable frame WR detached to reveal further components of the shaving head and their arrangement in the housing part G. Resiliently mounted adjacent to the end walls  13  and  14  in the housing central portion  15  are respective detent elements  18  and  19 . A cutter element S constructed as undercutter  22  is arranged on a coupling element K between the two end walls  13  and  14 . The coupling element K is movably arranged in the housing central portion  15  and coupled to the coupling element  11  for transmission of the drive motion of the drive pin  10 . Two retaining elements  28  and  29  are provided on the coupling element K, with the retaining element  28  extending in the direction of the end wall  14  while the retaining element  29  extends in the direction of the end wall  13 . 
     FIG. 4 shows the upper part of the housing  1  with a housing part G arranged thereon and a removable frame WR detachable in the direction of withdrawal indicated by the direction of arrow E, with the one bar  32  of the removable frame WR and the outer cutter coupled thereto being shown in part only. The removable frame WR is illustrated in a condition in which it is held by the retaining elements  28  and  29  being embraced by retaining elements  30  and  31 —see also FIG.  5 . With the removable frame WR in unlocked condition, the detent elements  18 ,  19  are disengaged from the detent notches  20 ,  21  provided in the removable frame WR, as shown, for example, in FIG. 4 by the broken lines representing the detent element  18  and the detent notch  20 . 
     The removable frame WR is essentially comprised of two bars  32  and  33  extending in the longitudinal direction—direction of arrow P—and end walls  34  and  35  connecting the bars  32  and  33 —see FIG.  5 —, as well as at least one cutter element S seated between the bars  32 ,  33  and the end walls  34 ,  35 . The inner surfaces  36  and  37  of the end walls  13  and  14  and the outer surfaces  38  and  39  of the end walls  34  and  35  extend in a wedge-shaped configuration relative to the vertical center axis V of the dry shaving apparatus TR, such that the relative distance of the end walls  13  and  14  in the area of the housing central portion  15  is smaller than the relative distance of the end walls  13  and  14  at the level of the cutter element S. This shape has the result that with the removable frame WR locked with the housing part G, the end walls  34  and  35  touch or nearly touch the inner surfaces  36  and  37  of the end walls  13  and  14 . In unlocked condition in which the removable frame WR is initially held by the retaining elements  28  to  31 , the end walls  34  and  35  are at a small relative distance W to the inner surfaces  36  and  37  and also the longitudinal side walls  53 ,  54  of the housing part G—see also FIG.  8 . 
     Provided on either end wall  34  and  35  is an inwardly extending stop  40  and  41 , respectively, and an outwardly extending stop  42  and  43 , respectively. The outer shape of the stops  40  and  41  on the side close to the undercutter  22  and the shape of the longitudinal ends  44  and  45  of the undercutter  22  and the positioning of the stops  40  and  41  on the removable frame WR in cooperation with the undercutter  22  are adjusted relative to each other in such manner that, with the removable frame WR locked with the housing part G, the stops  40  and  41  are able to slide into the undercutter  22  without adversely affecting the undercutter&#39;s oscillating motion. 
     Operation of the pushbuttons  16 ,  17  unlocks the removable frame WR. The removable frame WR sliding with its detent notches  20 ,  21  over and past the detent elements  18 ,  19  is then movably held in a predetermined holding position by resilient arms of the retaining elements  30 ,  31  partially embracing the retaining elements  28 ,  29 . 
     Once the removable frame WR is transferred to the holding position, the wedge shapes of the outer surfaces  38 ,  39  of the removable frame and the inner surfaces  36 ,  37  of the end walls  13 ,  14  extending parallel thereto result in a distance W between the respective inner surface  36 ,  37  and the respective outer surface  38 ,  39 . Each distance W ensures initially a back-and-forth movement of the removable frame WR in the directions of arrow P, in addition to providing a gap allowing the passage of hair dust, if any. Furthermore, between at least one of the longitudinal side walls  53 ,  54  of the housing part G and at least one of the bars  32 ,  33  of the removable frame WR at least one other slit-shaped distance W for the passage of hair dust is produced. 
     The distance W may be constructed as a slit-type circumferential gap resulting from the transfer of the removable frame WR from the locked position to the holding position, which gap may be of uniform size or, alternatively, of different dimensions. 
     By virtue of the transfer of the removable frame WR to the holding position, the two stops  40 ,  41  occupy a position altered relative to the undercutter  22 , in which position the stops  40 ,  41  are prevented from entering the undercutter  22 . The distance D of the respective longitudinal ends  44 ,  45  relative to the stops  40 ,  41  is dimensioned such as to ensure that, with an undercutter  22  set in oscillation by activation of the electric drive mechanism, the longitudinal ends  44 ,  45  of the undercutter  22  act upon the stops  40 ,  41  in pulse fashion in order to effect a back-and-forth or shaking movement of the removable frame WR in the direction of motion direction of arrow P—of the undercutter  22 . By means of the pulses impacting on the removable frame WR by the undercutter  22 , the relatively fine hair dust becomes dislodged from the walls of the removable frame WR, the undercutter  22  and the walls of the housing part G, falling, with the dry shaving apparatus TR held horizontally, for example, through the apertures, as through the slits defined by the distances W, formed between the housing part G and the walls of the removable frame WR to the outside. 
     The cleaning of all the walls enclosed by the removable frame WR may be optimized by a further arrangement. To accomplish this, the outwardly extending stops  42 ,  43  are provided on the end walls  34 ,  35  of the removable frame WR, by means of which stops the distance W of the outer surfaces  38 ,  39  of the removable frame WR relative to the inner surfaces  36 ,  37  of the end walls  13 ,  14  is reduced to a gap W 1  whose width is to be determined and fixed under practical considerations applicable to the case in question, here the construction of a shaving head. The stops  42 ,  43  are effective to transmit the pulses impacting on the stops  40 ,  41  by an oscillating undercutter  22  to the end walls  13 ,  14  of the housing part G in order to effect likewise a vibration aimed to support the cleaning process. 
     FIG. 5 shows a perspective view of the removable frame WR in which a long hair cutter unit LHS comprised of an outer cutter and an undercutter with a coupling element is positioned between two outer cutters  25 ,  26 , attached in arched form, of a respective short hair cutter unit KHS, and also a sectional view of the bar  32 , the undercutter  22  and the end wall  35 , such as to reveal the coupling element K transmitting the drive motion to the respective undercutters of short hair cutter unit KHS and long hair cutter unit LHS, together with the retaining device HV holding the removable frame WR. Formed on the housing wall of the coupling element K are the retaining elements  28 ,  29  of which the retaining element  29  is shown. The coupling element K which is adapted to be set in a reciprocating motion by the electric drive mechanism A of the dry shaving apparatus TR is coupled via two drive elements  48 —of which only one is shown—in a driving relationship to the respective undercutter  22  of the two short hair cutter units KHS provided in the removable frame WR, and via the drive element  47  and the coupling element  46 , to the undercutter  49  of the long hair cutter unit LHS positioned between the short hair cutter units KHS. Formed at either end of the fork-shaped coupling element  46 —see FIG.  6 —is a respective retaining device HV, with the relative distance of the fork ends being dimensioned such that these, upon embracing the retaining elements  28  and  29 , make engagement with the wall of the housing of the coupling element K. The retaining device HV is of a fork-shaped construction, having bead-type projections formed on the ends of the fork arms  50 ,  51 , which in their capacity as retaining beads  55 ,  56  are spaced from each other a specific relative distance. The fork arms  50  and  51  of the retaining elements  30  and  31  are elastic so as to ensure withdrawal of the removable frame WR from the housing part G, which is accomplished by the fork arms  50  and  51  with their integrally formed retaining beads  55 ,  56  spreading apart elastically in accordance with the dimensions of the retaining elements  28  and  29 . The embodiment of FIG. 5 shows the removable frame WR in the holding position illustrated in FIG. 4 in which the detent elements  18  and  19  are disengaged from the detent notches  20  and  21 . In this holding position the slit formed by the fork arms  50  and  51  and bounded by the retaining beads  55 ,  56  ensures clearance of movement for the removable frame WR driven by the coupling element K. Formed on the end wall  35  is a stop  43  by means of which the oscillating motion of the removable frame is transmittable to the end wall  13  of the housing part G. 
     FIG. 6 shows an exploded view of the coupling element K, the undercutters  22  coupled thereto and the removable frame WR, including a part sectional view—see also FIG.  4  and FIG.  5 —of the bar  32  and the end wall  35  of the removable frame WR. The drive element  47  for the undercutter  49  of the long hair cutter unit is provided between the two undercutters  22  coupled to the coupling element K and associated with the outer cutters  25  and  26 . The undercutter  49  is adapted to be coupled to the drive element  47  via the coupling element  46  for setting the long hair cutter unit in operation. Integrally formed at either end of the fork-shaped coupling element  46  is the retaining device HV with its fork arms  50  and  51 . 
     FIG. 7 shows a sectional view of the housing part G in the area of the detent elements  18  movable in relative opposite direction in the housing part G and their associated detent notches  20 , as well as of the removable frame WR receiving, in the embodiment shown in this Figure, the outer cutters  25  and  26  of a respective short hair cutter unit KHS and also a long hair cutter unit. Formed in the bars  32 ,  33  extending in the longitudinal direction of the removable frame WR—see FIG.  5 —is a respective detent notch  20 ,  21  having at least one sloping seating surface for engagement with a respective detent element  18 . Seated between the two detent elements  18  is a spring element  52  by means of which the two detent elements  18  are held in a locked position in which they protrude from the respective longitudinal side wall  53  and  54  of the housing part G. When the removable frame WR is removed from the housing part G, the sloping surfaces of the detent notches  20  exert a pressure on the detent elements  18  which project from the housing part G a small amount, moving the detent elements in opposition to the pressure of the spring element  52  into the interior of the housing part G until the bars  32  and  33  have traveled past all detent elements  18  and  19  provided, in order to be subsequently held in the holding position provided by the retaining device HV—see FIG.  5 . 
     With the removable frame WR in the holding position HV, the detent notches  20 ,  21  of the removable frame WR are above the detent elements  18 ,  19  projecting from the housing part G—see FIG.  8 . By shaping adjacent walls of the housing part G and of the removable frame WR differently, a distance W allowing the passage of hair dust results between the wall of the respective bar  32 ,  33  and the respective neighboring wall of the housing central portion  15  of the housing part G. 
     The longitudinal side walls  53 ,  54  of the housing central portion  15  extend in wedge shape, that is, at an inclination towards the vertical center axis V, with the area of cross section of the housing central portion  15  tapering in the direction of the cutter elements S provided. The inner walls of the bars  32 ,  33  of the removable frame WR differ from this shape by being constructed such that on transfer of the removable frame WR from the locked position to the holding position a distance W is producible between at least one longitudinal side wall  53 ,  54  of the housing part G and at least one wall of a bar  32 ,  33  of the removable frame WR. This may be accomplished, for example, by aligning the wall of the bar  32 ,  33  either parallel to the center axis V—not shown—or at an inclination to the center axis V, the latter at a wedge angle a smaller than the wedge angle P defined between the longitudinal side wall  53 ,  54  of the housing part G and the vertical center axis—see FIG.  7  and FIG.  8 .