Patent ID: 6851150

Claim:
A block head structure of an electric toothbrush comprising: a block head sleeve, a set of bristles, a connecting portion and a driving axle bush, wherein said block head sleeve is provided with said set of bristles on the front end thereof, and with said connecting portion on the rear end thereof; said driving axle bush is provided in said block head sleeve and between said set of bristles and said connecting portion; when said block head is connected with a block handle, said connecting portion is slipped over and connected to a driving end on said block handle, a driving axle thus is inserted and engaged in an axle hole of said driving axle bush, thereby, when said driving axle is rotated rightwards and leftwards repeatedly, said driving axle bush and said set of bristles are rotated simultaneously; said block head structure is characterized in that: said driving axle bush has an excavated section to receive a driving surface of said driving axle after assembling said driving axle bush with said block handle; a bridge-like member is provide above said excavated section, the front and the rear ends of said bridge-like member are connected with said driving axle bush, the top surface of said bridge-like member is nearby said axle hole; the radial amplitude of said axle hole where said bridge-like member locates is smaller than the radius of said driving axle where said driving surface is; thereby when said driving axle is slipped into said axle hole, said top surface of said bridge-like member is elastically expanded outwardly by abutment and pressing of said driving surface, hence a reaction force is generated to forcedly press said driving surface with said top surface; thereby, said driving axle and said driving axle bush are positioned simultaneously axially and radially, so that when said driving, axle is rotated rightwards and leftwards repeatedly, said driving axle bush and said set of bristles are rotated simultaneously.