beginning with fig1 , an electric toothbrush head 10 includes a neck 12 which is connected to a bristle support 14 . bristles 16 on support 14 are oscillated in a rotary movement through an arc of between about +− 15 to 90 degrees , more preferably +− 20 to 50 degrees as in a conventional electric toothbrush . fig2 shows support 14 in an exploded side view . an interdental probe 18 is secured to a slider core 20 in the center of bristles 16 . probe 18 can be a single large bristle or a tuft of much smaller bristles . alternatively , core 20 can be enlarged to accommodate a plurality of probes ( not shown ), one of which may be positioned in the center of the core ( as in fig1 ), with the remainder of the probes being positioned on the core away from its center . a pair of cam follower pins 22 are secured to opposite sides of the lower portion of core 20 . core 20 is positioned inside of a brush base 24 such that pins 22 are forced to ride along respective cam tracks 26 as well as respective vertical slider tracks 28 ( one slider track is hidden behind the other ). a retaining pin 30 rides in a track 32 to retain base 24 within a housing 34 . a guide / rotation pin 36 passes through a hole in the bottom of housing 34 and is secured to base 24 . operation of support 14 will be explained with reference to fig2 , 3 a and 3 b . pin 36 is oscillated about its long axis by a drive mechanism ( not shown ) in neck 12 . the drive mechanism can be of conventional design . oscillation of pin 36 causes brush base 24 and bristles 16 to oscillate in a rotary pattern . pin 30 retains base 24 within housing 34 . oscillation of base 24 causes core 20 and probe 18 to oscillate with the base because pins 22 ride in track 28 of the base . pins 22 also ride in respective tracks 26 in the housing , thus causing core 20 and probe 18 to move up and down relative to bristles 16 during oscillation of brush base 24 . fig3 a and 3b show that a preferred extension of probe 18 from its lowest to highest position is about 5 mm . in an alternative embodiment , all of bristles 16 are eliminated , leaving only probe 18 for cleaning teeth . this embodiment would be used primarily for cleaning interdental spaces , not for cleaning the other surfaces of teeth . turning to fig4 - 7 , a second embodiment of the invention will be described . a brushead 40 can be attached to a handpiece ( not shown ) of an electric toothbrush . a driveshaft ( not shown ) protrudes out of the handpiece and can effect an oscillating rotation . brushhead 40 includes a tube 42 in which a shaft 44 is located . the rear end of tube 42 fits into the housing ( not shown ) of the handpiece . shaft 44 engages the driveshaft of the handpiece . a pin 46 is press fitted into shaft 44 . pin 46 can rotate at its free end in a bearing hole 48 in a front part 50 of tube 42 . axis 52 of pin 46 coincides with the axis of the driveshaft of the handpiece . a pivot 54 can rotate in a bearing hole 56 situated in front part 50 of tube 42 . pivot 54 is retained in hole 56 by a ring 58 . a brush base 60 is press fitted onto pivot 54 . brush base 60 has holes 62 in which tufts of bristles 64 are secured . a cross pin 66 is welded onto the free end of pivot 54 . both ends of cross pin 66 retain brush base 60 on pivot 54 by interaction with a shoulder 68 of the brush base . the central part of cross pin 66 is placed in a bearing hole 70 of a rocker 72 . rocker 72 can swivel about cross pin 66 and contains holes 74 in which tufts of bristles 76 are secured . shaft 44 includes a bearing hole 78 in which a drive rod 80 can move . the distance between axis 52 of pin 46 and an axis 82 of drive rod 80 is a radius r 1 . a stud 84 is welded onto the free end of drive rod 80 . the distance between an axis 86 of pivot 54 and an axis 88 of stud 84 is a radius r 2 . stud 84 can move in a bearing seat 90 in brush base 60 . at one end of stud 84 is carried a ball 92 which can move in a cylindrical slot 94 in rocker 72 . when shaft 44 is oscillated about axis 52 through an angle of +− alpha 1 about pin 46 , two different motions are induced . first , brush base 60 and rocker 72 are oscillated in a rotating manner through an angle of +− beta 1 about pivot 54 in bearing hole 56 . this oscillating rotation causes bristles 64 to wipe plaque off teeth like a broom . second , rocker 72 is oscillated in a rotating manner through an angle of +− gamma 1 about cross pin 66 in bearing hole 70 . oscillation of rocker 72 about pin 66 causes bristle tufts 76 to loosen plaque like a chisel . two cycles of oscillation of rocker 72 about pin 66 occur for every one cycle of oscillation of base 60 and rocker 72 about pivot 54 . the relations between the oscillation angles alpha 1 to beta 1 and alpha 1 to gamma 1 depend only on radii r 1 and r 2 . referring to fig8 - 12 , a third embodiment of the invention will be described . the third embodiment modifies the relationship between the oscillation angles , primarily to increase the gamma angle of the oscillating rotation of rocker 72 . the basic features of the third embodiment remain unchanged from the second embodiment . the main difference is in the location of the drive rod . in the mid - position of the oscillating rotation of a shaft 100 , a drive rod 102 is located at a distance e from a median plane 104 of a brushhead 106 . a stud 108 is welded laterally on a free end of drive rod 102 with a distance e between the center - lines . stud 108 is movable in a bearing seal 110 of a brush base 112 . when a drive shaft 114 is in a mid - oscillation position , stud 108 is in a median plane 116 of brush base 112 . drive rod 102 can move in a bearing hole 118 in shaft 114 . bearing hole 118 is situated in the distance e from median plane 104 of shaft 114 when the shaft is in its mid - oscillation position . when shaft 114 is oscillated about median plane 104 through an angle of +− alpha 1 , two different motions are induced . first , brush base 112 and rocker 72 are oscillated in a rotating manner through an angle of +− beta 2 which is smaller than +− beta 1 about axis 120 . second , rocker 72 is oscillated in a rotating manner through an angle of +− gamma 2 which is bigger than +− gamma 1 about cross pin 66 . the relations between the oscillation angles alpha 1 to beta 2 and alpha 1 to gamma 2 depend on radii r 1 and r 2 as well as on the distance e . in embodiments 2 and 3 of the invention , one component of the rocking motion of rocker 72 causes bristles 76 to move up and down ( i . e . substantially parallel to pivot 54 ) relative to bristles 64 . fig1 and 14 disclose a toothbrush head 130 which is similar in function to the head of fig4 . the major difference is that tufts of bristles 132 on a pivot bar 138 are tilted away from the perpendicular ( to the top surface 140 of the pivot bar 138 ) at an angle 134 of between about 1 - 20 degrees . preferably the bristles 132 are tilted along the direction of oscillation of bristles 136 on a brush base 142 . such tilting of bristles 132 provides better interdental penetration during the respective upstrokes of pivot bar 138 , particularly for the tuft ( s ) on bar 138 which are being moved by head 130 in the tilt direction . it is preferable that tufts of bristles on both sides of bar 138 have the same tilt angle and are tilted in the same direction ( i . e . in the same plane ). alternatively , tufts of bristles on opposite sides of the bar can be tilted in opposite directions . as shown in fig1 and 14 , when pivot bar 138 is oscillated relative to brush base 142 , the top surface 140 of pivot bar 138 and the top surface 144 of brush base 142 are capable of lying in substantially a same plane ( when pivot bar 138 is aligned with brush base 142 ) during the operation of the electric toothbrush . the invention has been described with reference to several embodiments including a preferred embodiment . however , it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention .
a toothbrush head includes a base portion having a first surface and a pivot portion having a first cleaning element holder having a second surface , wherein the second surface is superjacent the first surface . the pivot portion also includes a second cleaning element holder and a third cleaning element holder which extend longitudinally from the first element holder . the head includes a pivot element for pivotally coupling the base portion and the pivot portion .