Abstract:
The invention relates to an electric shaver comprising a housing ( 1 ) and a shaving head ( 2 ) which comprises at least one cutting system, and which is pivotably connected to the housing ( 1 ), and further comprises means for locking this pivoting motion at several predetermined positions, whereby the shaving head ( 2 ) comprises a multitude of notches ( 23 ). To improve the function on comfort of the shaver the housing ( 1 ) provides a switch element ( 6 ) which is connected to at least one engaging element ( 10 ) that is adapted for being coupled with at least one of the notches ( 23 ).

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to an electric shaver. 
       BACKGROUND OF THE INVENTION 
       [0002]    Electric shavers of the type initially referred to are known for example from the U.S. Pat. No. 3,797,105. This document discloses an electric dry shaver having a handle and a shaving head pivotably connected to that handle. The shaving head comprises a shaving element of the rotary type and its driving motor. The handle is adapted to carry the batteries and comprises a pair of arms extending from the handle to bear the rockable shaving head. Between the shaving head and the arms clicking means are provided to lock the head at predetermined rocked angles. Due to those clicking means the shaving head itself is never completely freely pivotable relative to the handle. 
         [0003]    An electric shaver which comprises a shaving head being freely pivotable connected to the housing of the shaver is known from the U.S. Pat. No. 5,542,179. The advantage of such an electric shaver is that the shaving head is able to adapt perfectly to the contour of the skin to be shaved. However, sometimes, for example when shaving under the nose, there is a need to fix the shaving head relative to the housing at least temporarily. 
       SUMMARY OF THE INVENTION 
       [0004]    It is therefore an objective of the present invention to overcome all the drawbacks of the known shaving systems especially such as discussed above and to provide an improved electric shaver of the type initially referred to such to ensure an optimal handling of the shaver in any shaving situation. 
         [0005]    The electric shaver according to the invention enables a fixing of the shaving head relative to the housing if needed whereby the fixing can take place at a multitude of different predetermined angles. 
         [0006]    The electric shaver according to the invention comprises a housing and a shaving head being pivotably connected to the housing. The shaving head comprises at least one cutting element for cutting hairs. The shaver further comprises means for locking the pivoting motion of the shaver head at several predetermined positions, whereby the shaving head comprises a multitude of notches to be coupled with an engaging element, whereby the engaging element is connected to a switch element which is provided at the housing. This improves the handling of the shaver during the shaving process and leverages the shaving comfort. Whenever needed, the user of the electric shaver is enabled by simply actuating the switch element to lock the shaving head in one of a multitude of possible locking angles by keeping the shaver rested in the user&#39;s hand. 
         [0007]    Preferably, the switch element is apt to be switched into at least a coupled state or in a decoupled state for the shaving head. 
         [0008]    In a preferred embodiment of the invention, the engaging element provides a preloaded connection with the shaving head in case the engaging element is switched in the coupled state. The engaging element preferably comprises a spring element. 
         [0009]    Another preferred embodiment of the invention is characterized in that the switch element is connected to the engaging element via a pivoted lever. Preferably, the pivot bearing of this pivoted lever is arranged at the housing of the shaver. To avoid that the shaving apparatus is top heavy but is rather balanced with respect to the distribution of the weight, it is preferred that the electric motor for driving the cutting system(s) of the shaving head is located in the housing. 
         [0010]    Often there is a wish to integrate an additional tool in the electric shaver which contacts the skin during its application, for example an additional cutting system or an applicator for fluid or the like. Therefore, a preferred embodiment of the invention comprises a slider which is slidably arranged at the housing in a way that its upper end can get into the pivoting range of the shaving head. To avoid an interference of the slider and the rockable shaving head, a mechanical actuating element is provided to displace the shaving head and daff it aside in order to allow the slider to travel into the direction of its upper end. Preferably, the mechanical actuation element is an operating lever whose pivot bearing is arranged at the housing. To realize this embodiment without a huge mechanical effort the shaving head provides an outer stop to be charged by the actuating lever. 
         [0011]    Preferably there is an additional cutting system arranged at the top of the slider, especially it is constructed as a long-hair trimmer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The invention will be further elucidated by detailed explanation of exemplary embodiments and by reference to the figures. In the figures 
           [0013]      FIG. 1  is an illustration of a front view of an electric shaver according to the invention, 
           [0014]      FIG. 2  is a side view of the shaving head and the locking mechanism, 
           [0015]      FIG. 3  is an enlarged view of the shaving head in the locked position, 
           [0016]      FIG. 4  is a side view of the shaver in an unlocked position of the locking mechanism, 
           [0017]      FIG. 5  to  FIG. 8  is an illustration of the pivoted lever according to the invention in different positions, 
           [0018]      FIG. 9  and  FIG. 10  are side views of the electric shaver having a slider which is shown in different positions, 
           [0019]      FIG. 11  is a perspective view of the slider, the long-hair trimmer and the operating lever, and 
           [0020]      FIG. 12  is an enlarged view of the operating lever. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]      FIG. 1  shows an illustration of an electric shaver having a housing  1  and a shaving head  2  which is connected via bearing arms  3  with the housing in a manner so that it is able to pivot around the lateral axis x. The shaving head  2  encompasses cutting systems having an inner cutter  4  and an outer cutter  5 . This kind of features is known in general for example from the U.S. Pat. No. 5,542,179. A housing  1  accommodates the electric motor (not shown) for driving the undercutter  4  which is coupled to the electric motor in a known manner. Housing  1  further encompasses the batteries (not shown) for energizing the electric motor.  FIG. 1  shows a switch element  6  which is slidably mounted on the front side of the housing  1  and adapted to be moved along the vertical axis y. In  FIGS. 1 and 2 , the switch element  6  is shown in its lower (locking) position. Switch element  6  comprises a catch  7  for the left one of the two free ends of a pivoting lever  8  which is connected to the housing  1  via a pivot bearing  9 . The right free end of the pivoting lever  8  is constructed to control the free end  12  of the engaging element  10 . The engaging element  10  comprises further a fixed end  11  which is clamped at the housing  1 . The engaging element  10  is generally constructed as a beam in bending having, according to  FIGS. 3 and 4 , a fixed end  11  clamped to the housing and a free end  12  which is controlled by the pivoting lever  8  and guided via a cam  13  of a guidance plate  14  (see  FIGS. 5 to 8 ). 
         [0022]    As can be taken best from the  FIGS. 1 to 4 , the engaging element  10  is shaped essentially as a squared U with a first arm  15  providing a fixed end  11 , a middle section  17  and a second arm  16  which provides the free end  12 . Seen from the front according to  FIG. 1  the fixed end  11  is located to the right of the pivoting lever  8  whereby its first arm  15  extends to the back of the housing where the spring wire, of which the engaging element  10  is made of, is bent to the right hand side where it leads as a middle section  17  to the right. The middle section  17  is arranged in parallel to the back of the housing. At the right end of the middle section  17 , there is a rectangular curve followed by the second arm  16  which is directed to the front of the housing. The second arm  16  provides a hump-like protuberance  18  located approximately in the middle of the second arm  16 . The protuberance  18  divides the second arm  16  into two parts whereby each of the two parts is inclined upwardly into the direction of the protuberance  18 . 
         [0023]    At its free end  12  the second arm  16  of the engaging element  10  is guided through the cam  13  of the guidance plate  14 . The second arm  16  is projecting with its free end  12  to the outside of the guidance plate  14  and is acted upon by the pivoting lever  8 . 
         [0024]    The guidance plate  14  is shown in  FIG. 5 . It comprises a vertical slot  19 . The width of the slot  19  is a little bit broader than the diameter of the second arm  16 . The cam  13  has a vertical section  20  and an inclined section  21 . 
         [0025]    In  FIGS. 1 to 3  and  6 , the pivoting lever  8  is shown in a position where the switch element  6  is in its downward lock position and the shaving head  2  is locked via the protuberance  18  of the engaging element  10 . The engaging element  10  is preloaded in a way that its second arm  16  is biased upwardly into the direction of the shaving head  2 . Consequently the free end  12  of the second arm  16  rests on the upper end of the vertical slot  19  if unaffected by the pivoting lever  9  via its convex cam section  22 . This position is illustrated in  FIG. 6 . As can be taken best from  FIG. 3  in this position—unaffected by the pivoting lever  9 —the protuberance  18  is pressed into one of the nuts  23  provided in the bottom  24  of the shaving head  2 . The bottom  24  is curved with an radius which equals the distance between axis X and the bottom  24 . The nuts  23  are essentially V-shaped having a rounded ground. The pressing force of the protuberance  18  into the nuts  23  due to the elastical preload of the second arm  16  is about 4 N. Predetermined by this value of the pressing force and the angle of the flanks as well as the distance between the lateral axis X and the bottom  24  it is possible to override the locking force with a pivoting force of about 6 N if applied circumferentially at the bottom  24 . This means that even if the shaving head  2  is “locked” it can be pivoted if the pivoting force is high enough which means that in this situation the engaging element has the function of a clicking mechanism whereby the user can override the locking force by applying a tangential force which exceeds a certain value (6 N). This force is predetermined at a value which is higher than the pivoting forces which occur during the normal shaving process.  FIGS. 4 and 8  are depicting the unlocked state of the shaving head  2  where the switch element  6  is in its upward end position. The transition from the locked position as shown in  FIG. 6  to the unlocked position is illustrated in  FIGS. 6 to 8 . Starting from  FIG. 6 , the pivoting lever  8  is turned clockwise around the pivot bearing  9  via the catch  7  which is connected to the switch element  6 . The bracket type catch  7  is receiving the spherical end portion  25  of the pivoting lever  8  which is at the left-hand side of the pivoting lever  8 , as illustrated in  FIGS. 6 to 8 . When moving the switch element  6  upwardly and consequently starting turning the pivoting lever  8  clockwise, the convex cam section  22  located at the right side end of the pivoting lever  8  is pressing down the free end  12  of the second arm  16  of the engaging element  10  vertically along the vertical slot  19 . When the free end  12  has reached the end of the vertical section  20  of the slot where the inclined section  21  starts—this is illustrated in FIG.  7 —the free end  12  follows the inclined section  21  and is pushed to the right side following the inclined section  21  as well as the convex cam section  22 . The end position of this rotation of the pivoting lever  8  when also the switch element has reached its upper end position is illustrated in  FIG. 8 . When the free end  12  has reached its end position according to  FIG. 8 , the biasing force of the engaging element is essentially received by the guidance plate  14 . The pivoting lever  8  is nearly released from this biasing force. It should be noted that the switch  6  may provide a detent which enables a snapping to the housing  1  in its end positions. 
         [0026]      FIGS. 9 and 10  are showing a version of an electric shaver which provides an additional long-hair trimmer  26  which is arranged at the back of the housing  1 . The long-hair trimmer  26  is located at the top of a slider  27  which is slidably born on the housing  1 . It becomes evident from  FIG. 9  that in case of a linear movement of the slider  27  in the direction of the arrow A a collision of the long-hair trimmer  26  and the shaving head  2  could occur if the shaving head  2  is pivoted clockwise above a certain angle since the areas of movement of the slider  27  and of the shaving head  2  are overlapping. To avoid this collision the following mechanism is provided. An operating lever  28  is connected via a pivot bearing  31  at the top end  38  of the housing  1 . The operating lever  28  has a first end  32  and a second end  33 . When the slider  27  is in its retracted parking position as shown in  FIG. 9 , the second end  33  of the operating lever  28  rests in the catch  30  which is provided on the inner side of the slider  27 . The operating lever  28  is elastically preloaded by a wound spring  34 , which spring is illustrated in the  FIGS. 11 and 12 . According to the view of  FIG. 9 , the spring  34  is biasing the operating lever  28  counter-clockwise. As can be taken best from  FIG. 10 , the catch  30  provides a concave contour  35  and a stop  36  which is essentially perpendicular to the vertical extension of the slider  27 . The bottom  24  of the shaving head  2  provides a stop  29  which interacts with the first end  32  of the operating lever  28 . 
         [0027]    When starting from the position as shown in  FIG. 9 , the slider  27  is moved upwardly according to the arrow A and the stop  36  of the catch  30  turns the operating lever  28  clockwise around the pivot bearing  31 . In case the shaving head  2  is swung out to the right (clockwise around the lateral axis X), the first end  32  of the operating lever  28  acts upon the outer stop  29  to rotate the shaving head counter-clockwise to clear the travel of the slider  27 . Hereby the operating lever  28  is turned against the preload of the spring  34 . After a certain distance of travelling of the slider  27  the operating lever  28  is completely swung out into the position shown in  FIG. 10 . At that point of travel of the slider  27 , the second end  33  of the operating lever is acted upon by the support area  37  which holds the operating lever in the position as shown in  FIG. 10 . In this position the drive chain of the long-hair trimmer  26  is coupled in a generally known way to the electric motor (not shown) and the respective cutting element of the long-hair trimmer  26  are driven in a known way. 
         [0028]    When—starting from the extracted position as shown in FIG.  10 —the slider  27  is drawn back into its parking position, the long-hair trimmer  26  is decoupled from the electric motor and the operating lever  28  remains in the position as shown in  FIG. 10  since the support area  37  acts upon the second end  33  of the operating lever  28 . If the upper end of the support area  37  reaches the second end  33  of the operating lever  28  at the stop  36 , the operating lever  28  is pivoted counter-clockwise into the position as shown in  FIG. 9 . This counter-clockwise rotation is forced by the spring  34 . In this parking position the shaving head  2  is free to pivot around the lateral axis X. The relationship of the two levers of the operating lever  28  are chosen in a way that the shaving head  2  can be pushed away counter-clockwise even if the engaging element  10  is in its locked position. 
         [0029]    In case the shaving head  2  is completely blocked, for example manually by the user of the shaver, the following will happen when the slider  27  is moved upwardly into an extracted position as shown in  FIG. 10 . As can be taken from  FIG. 12 , the pivot bearing  31  is carried out by two pins  39  and  40  which are supported in a recess  41  which is provided at the top end  38  of the housing  1 . The spring  34  does not only provide the restoring torque for the operating lever  28  as explained for the  FIGS. 9 and 10  but additionally provides a biasing force to the operating lever into the downward direction. Therefore, the pins  39  and  40  are pressed in the direction of the recess  41 . 
         [0030]    As shown in  FIG. 11 , the spring  34  additionally provides a torque moment T in counter-clockwise direction. 
         [0031]    If now, as mentioned before in a blocked system (completely blocked shaving head  2 ), an overload occurs when the slider  27  is shifted upwardly, the operating lever  28  can be rotated against the torque moment T so that the second end  33  of the operating lever  28  is moving laterally away from the catch  30  into the direction of the arrow D. The slider  27  can then be moved upwardly until it contacts the bottom  24  of the shaving head  2 . If the slider  27  is then moved back again into its retracted parking position, the second end  33  is pushed back into the catch  30  by the biasing torque T. 
         [0032]    The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.” 
         [0033]    Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern. 
         [0034]    While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.