Abstract:
An accessory mount for an electric toothbrush having a motor which is arranged in a handpiece for driving vibration-generating mechanism. The mount including an elongate protective cover attachable to the handpiece. The vibration-generating mechanism is arrangeable in an interior of the elongate protective cover. A sleeve is fitted onto the protective cover so as to cover the protective cover over at least part of its length.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a mechanically driven device for cleaning the oral cavity, in particular an electric toothbrush, and to an accessories mount for a device of this type. 
     2. Discussion of the Prior Art 
     Electric toothbrushes generally comprise a handpiece, in which the electric drive means are accommodated, a brush head and a spindle which connects the handpiece to the brush head. 
     An electric toothbrush of this generic type is known from European reference EP 0 850 602, which was filed,in the name of the present applicant. This toothbrush essentially comprises a handpiece, a brush head, a pin which connects the handpiece to the brush head and a motor which is arranged in the handpiece and sets an unbalanced mass in rotation. The unbalanced mass is arranged in the vicinity of the brush head and is set in rotation by an elongate pin which is coupled to the output spindle of the drive motor. The housing part which bears the drive means is attached to the handpiece via damping means in order to prevent vibrations in the handpiece. During use, the rotary movement of the unbalanced mass generates a centrifugal force which in turn, in the brush head, generates vibrations which are damped in the handpiece. 
     This device comprises a brush which is arranged at the end of the brush head in order to clean the oral cavity. Although the way in which it functions is satisfactory, the used brushes cannot be replaced since they remain fixedly connected to the device. 
     Toothbrushes are already known from the prior art. According to some proposals, the brushes are removably attached to the end of the brush head, while according to other proposals they are connected to a mount which is arranged removably on the pin which connects the brush to the drive mechanism. In both cases, there are sealing problems, since the water and toothpaste can penetrate into the interior of the device; for design reasons, the attachment parts are connected to drive parts of the toothbrush which are arranged in the interior. In addition, only the brush is exchanged, while its mount remains attached to the device, and for this reason hygiene requirements are no longer satisfied if it is intended for the device to be used by another person as well. 
     SUMMARY OF THE INVENTION 
     Therefore, one object of the invention is to eliminate the above-mentioned drawbacks and to provide an electric toothbrush which is fitted with an accessories mount, in which the used brushes can be replaced easily and in which the required hygiene conditions are satisfied in the event of use by different people. 
     Another object of the invention is to provide an accessories mount for electric toothbrushes to which different accessories for cleaning the oral cavity can be removably and therefore exchangeably attached. 
     A further object of the invention is to provide an accessories mount of simple structure for electric toothbrushes, which is easy to fit to the device and to remove again from the device, which functions reliably and which can be manufactured as a mass-produced item at the lowest possible price. 
     According to the invention, these objects are achieved by means of an accessories mount for electric toothbrushes which is equipped with a motor arranged in the handpiece for driving the means which generate the vibrations in the brush head. The means which generate the vibrations are arranged in the interior of an elongate protective cover which is attached to the handpiece. The accessories mount comprises a sleeve which is fitted onto the protective cover and covers the latter over at least part of its length. 
     The means which generate the vibrations in the brush head, in particular the unbalanced mass and the spindle which sets the unbalanced mass in rotation, are arranged in the interior of the elongate protective cover, one end of which is fixedly connected to the handpiece of the device and the other end of which is arranged freely. The protective cover is designed as a closed part for sealing reasons. In addition, the accessories which are provided for cleaning the oral cavity are held by an accessories mount which is substantially formed by a sleeve surrounding the protective cover. 
     This has the advantage that all the components of the vibration mechanism are arranged in a hidden and encapsulated position and therefore do not come into contact with the fingers of the user. A protective cover of this type made from plastic also provides additional protection for people who are sensitive to metal. In addition, this solution ensures that there is a good seal against water and toothpaste, since the protective cover is designed as a closed part. 
     Another advantage is that each user has his own accessories mount, the length of the sleeve corresponding to the length of introduction into the oral cavity. As a result of the user changing the sleeve, at the same time the accessory is changed and therefore the outer surface of the protective cover which supports the sleeve remains clean. 
     The sleeve advantageously covers the protective cover over its entire length which projects beyond the handpiece. 
     The protective cover is thus protected by the appropriate sleeve which has been fitted during use over its entire length and is not exposed to contamination by cleaning liquid flowing along the sleeve. 
     The bottom end of the protective sleeve is advantageously connected to the handpiece by means of an elastic ring. 
     In an electric toothbrush as described in EP 0 805 602 which has been filed in the name of the applicant, the unbalanced mass is advantageously arranged in the vicinity of the brush head. The unbalanced mass is advantageously set in rotation by an elongate spindle, and the driving force of the motor is transmitted to the spindle via a flexible coupling arranged in the vicinity of the brush head. The fact that the rotation point is at a distance from the load point, in particular from the center of gravity of the unbalanced mass, increases the amplitude of the vibrations. The elastic ring which connects the end of the protective cover to the handpiece ensures that the vibrations are magnified in the brush head and are attenuated in the handpiece. 
     Preferably, the sleeve at its one end has attachment means for releasable attachment to the protective sleeve and, at its other, opposite end, has holding means for the accessories provided for cleaning the oral cavity. 
     The means for attaching and locking the sleeve on the protective cover are provided at a distance from the region which receives the toothpaste, so that the toothpaste cannot contaminate the locking mechanism and no functional problems occur. 
     The end of the sleeve which bears the accessories is advantageously oriented obliquely with respect to the longitudinal axis of the sleeve. 
     This configuration offers the advantage that the brush can be passed to the mouth in an ergonomic way, depending on the way it is handled by the user, but the mechanism accommodated in the protective cover remains aligned in a straight position. In addition, this obliquely oriented configuration exhibits good mechanical strength. 
     The angle between the end region of the sleeve and its longitudinal axis is advantageously between 8° and 20°, preferably 15°. It has been found that an optimum ergonomic design is achieved with an angle of inclination of this magnitude. 
     The means for holding the accessories are advantageously formed by a part which has an opening for receiving the accessories. 
     It is thus possible to insert various types of exchangeable accessories which have pegs with a suitable cross-sectional shape into the mount, with the accessories, in the most simple design in particular, being pressed into the receiving opening. The clear width of the receiving opening is advantageously of polygonal, preferably square design. 
     This has the advantage of providing a simple and reliable holding and locking means, the peg of the accessory being clamped into the receiving opening. 
     The receiving opening is preferably of continuous design. 
     In this way, it is possible for the accessory to be attached to one side or the other of the accessories mount, as desired. 
     According to a preferred embodiment of the invention, the accessory is formed by an oval brush. A brush of this type can be guided to the teeth in such a way that its larger diameter is oriented either parallel or perpendicular to the row of teeth, depending on the intended purpose, in particular that of cleaning the teeth, massaging the gums, etc. 
     According to another embodiment of the invention, the accessory is formed by a rotary piece with a conical tip. Such an accessory can be used in conjunction with an accessories mount according to the invention, preferably for cleaning the interdental spaces and the gum line. 
     According to another embodiment of the invention, the accessory may be formed by dental floss which is secured in a holder. 
     It is also possible for a dental-floss holder to be fitted to an accessories mount according to the invention, in which case the dental floss is arranged in a fixed position in the holder but it is possible to exchange the dental-floss holder or to attach it in an inclined position on one or the other side of the accessories mount. 
     The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a front view of an electric toothbrush with an accessories mount according to the invention; 
     FIG. 2 shows a front view of an accessories mount according to the invention; 
     FIG. 3 shows a section on line A—A from FIG. 1, through an accessories mount which is fitted on the toothbrush head; 
     FIGS. 4 a  and  4   b  show different arrangements of accessories and a plurality of individual accessories which can be used with the accessories mount according to the invention; 
     FIG. 5 shows an exploded view of the various components of an accessories mount according to the invention; and 
     FIGS. 6 a  and  6   b  show embodiments of an accessories mount according to the invention, with an oval brush in two different positions on the accessories mount. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The electric toothbrush  1  illustrated in FIG. 1 comprises a handpiece  2  and a brush head  4 , onto which an accessories mount  3  according to the invention has been fitted. The handpiece  2  accommodates an electric motor and a flexible connecting piece which connects the motor spindle to the brush head spindle  10 . 
     The brush head spindle  10  is formed by an elongate pin, in which the bottom end of the spindle  14  of an unbalanced mass  16  is secured. The top end of the spindle  14  is fitted into a corresponding opening in an elongate protective cover  18 . The brush head spindle  10  is made in by particular from plastic, while the spindle  14  and the unbalanced mass  16  are made from metal. The unbalanced mass  16  is advantageously semicircular in cross section, the center of the semicircle lying on the spindle  14 . At its two ends, the spindle of the unbalanced mass  16  is secured removably with respect to the adjacent parts. However, it is also possible to provide a fixed holder or for the pin  10 , the unbalanced-mass spindle  14  and the unbalanced mass  16  to be designed as a single part. 
     The cover  18  on one side bears the spindle  14  of the unbalanced mass  16 , the pin  10  setting the unbalanced mass  16  in rotation. On the other side, the cover  18  contains all the components so as to seal them in. The protective cover  18  is fixed into the handpiece  2 , the elastic sealing ring  7  ensuring a seal. This allows the electric toothbrush to be of compact and sealed design. 
     The accessories mount  3  according to the invention is fitted onto the protective cover  18  and connected to the latter via attachment means  28  on the brush head  4 . The accessories mount  3  comprises a sleeve  20 , the top end  20   b  of which is equipped with means  26  for holding the accessories which are required to clean the oral cavity and the bottom end of  20   a  which is equipped with the attachment means  28  for attaching it to the cover  18  or the toothbrush head  4 . 
     To ensure a firm and rotationally secure connection between the sleeve  20  which bears the accessory and the protective cover  18 , the protective cover  18  has a flattened top end  17  on one side, which interacts with a corresponding opening in the interior of the sleeve  20  of the accessories mount  3 . On the other side, the protective cover  18  has a bottom end which is provided with two cutouts  19 . 
     The means  28  for attaching the sleeve  20  to the protective cover  18  comprise, as can be seen from FIG. 3, a slide ring  32  which can slide along the bottom end of the sleeve  20  and is provided with two elastic tongues. The slide ring  32  is arranged in such a way that it is guided displaceably between two limit stops. The bottom limit stop corresponds to the locking position, in which the sleeve  20  is fixed on the protective cover  18 . The top limit stop corresponds to the open position, in which the sleeve  20  can be removed from the protective cover  18 . 
     The top end  20   b  of the sleeve  20  which forms the accessories mount  3  advantageously comprises an obliquely oriented section  21  with the holding means  26  arranged in its end region for various accessories  22 ,  22 ′ for cleaning the oral cavity. The angle of inclination of the section  21  is 8° to 20°, advantageously 15°, so that the accessories mount  3  is oriented obliquely forward or backward and the corresponding accessory  22  can thus be introduced into the mouth at an angle. 
     As can be seen from FIG. 5, the attachment means  26  are formed by a part  27  which is connected to the end section  21  of the sleeve  20 . The part  27  may be of removable design and provided with attachment means for attaching it to the sleeve  20 . However, the part  27  is advantageously formed integrally with the sleeve  20 . The part  27  has a continuous receiving opening  27 ′ into which the accessories  22 ,  22 ′ are fitted. 
     The opening  27 ′ is preferably of square design, but can alternatively be of any other polygonal or even, in extremis, circular shape. The accessory  22 ,  22 ′ which is fitted into the opening  27 ′ has a peg or pin  24  which matches the shape of the opening  27 ′. The accessories  22 ,  22 ′ are removably attached to the sleeve  20 , in particular by being clamped, being pressed in, by elastic means, by screw connection or by equivalent attachment means. Preferably, the accessories are attached by being clamped in an elastic holder. 
     All the components of the accessories mount  3 , in particular the sleeve  20 , the slide ring  32  and the accessories which are attached in the accessories mount  3  are advantageously made from plastic, which is beneficial for people who are allergic to metallic materials and allows mass production at low prices. 
     During use, an accessory  22  or  22 ′ is fitted into the sleeve end  21 , then the sleeve  20  is fitted onto the protective cover  18 , and the slide tube  32  is moved downward in order to lock the sleeve ( 20 ) on the brush head  4 . By pressing the on-off switch  8 , the electric motor which sets the spindle  10  and the unbalanced mass  16  in rotation is turned on. The spindle  10  is set in rotation via a flexible coupling arranged in the interior of the handpiece  2 , so that vibrations occur around a rotation point located in the handpiece  2 , and these vibrations are amplified because of the distance from the center of gravity of the unbalanced mass  16 . Due to the elastic sealing ring  7 , the vibrations maintain their amplitude in the brush head and are attenuated in the handpiece  2 . 
     The rotary movement of the unbalanced mass  16  generates the vibrations in the brush head  4 , the vibrations being transmitted to the accessory  22 ,  22 ′ which is attached to the top end of the accessories mount  3 . The vibrating accessory comes into contact with the teeth and/or the gums in order to clean the teeth and massage the gums. 
     As can be seen from FIGS. 4 a  and  4   b , the accessories attached to the accessories mount may be toothbrushes of various forms, in particular oval  22  or conical  22 ′ brushes which are used in particular to clean and care for the interdental spaces. It is also possible to use other accessories, for example dental floss which is secured in a holder which can be removed from the accessories mount  3 . 
     FIGS. 6 a  and  6   b  show the way in which an accessories mount  3  according to the invention is used with an oval brush  22 . The part which serves as holding means  26  comprises, as can be seen from FIG. 5, a square attachment opening  27 ′. Since the peg  24  of the brush  22  is square in cross section, there are two different options for attaching the oval brush  22  to the accessories mount  3 . Either the brush  22  is fitted on in such a way that its larger diameter is oriented parallel to the row of teeth (FIG. 6 a ) or the brush is rotated through 90° with respect to the first position (FIG. 6 b ). Since the receiving opening  27 ′ is of continuous design, the sleeve  20  has an obliquely oriented section  21  and can be attached to the cover  18  in two different orientations rotated through 180°, it is thus possible for an oval brush to assume eight different positions on the accessories mount. 
     Further improvements can be made within the scope of the invention. For example, it is possible to provide an uncoupling device which separates the brush from the holder if an excessive pressure is exerted on the brush. The brush is attached to a seat by means of a spring arranged in its holder, the holder being arranged in the accessories mount according to the invention. In the event of a defined pressure being exceeded, the brush would be separated from its seat, so that it is no longer connected to the vibration means. 
     It is also possible to provide an accessories mount  3  with slide rings of different colors in order to identify the accessories mount as a function of a specific use. 
     The invention is not limited by the embodiments described above which are presented as examples only but can be modified in various ways within the scope of protection defined by the appended patent claims.