Toothbrush and manufacturing method thereof

Abstract

A toothbrush includes a head and a plurality of bristles. Each bristle includes a first end exposed outside the head of the toothbrush, and a second, opposite end being placed in the head of the toothbrush. The second ends of the bristles are fused together, in bundles, to be thermally attached directly to the head of the toothbrush and/or to define a continuous layer in which at least some of the bundles are also fused together.

1 . A toothbrush, comprising:
 a head; and   a plurality of bristles, each of said bristles comprising a tapered first end exposed outside the head of the toothbrush, and a second, opposite end being placed in the head of the toothbrush,   wherein the second ends of the bristles are fused together, in bundles, to be thermally attached directly to the head of the toothbrush.   
     
     
         2 . The toothbrush of  claim 1 , wherein
 the head of the toothbrush further comprises a head insert which comprises
 opposite first and second surfaces, and 
 a plurality of through holes extending from the first surface to the second surface of said head insert; and 
   each of said bundles comprises several said bristles received in one of the through holes, with the respective second ends of the bristles protruding beyond the second surface of the head insert and defining a fused portion which is larger than a diameter of the respective through hole and which is thermally attached to the head insert.   
     
     
         3 . The toothbrush of  claim 2 , wherein
 several of said bundles are fused together at the respective fused portions to define a continuous layer that extends across the respective through holes in which said several bundles are received.   
     
     
         4 . The toothbrush of  claim 3 , wherein
 all of said bundles are fused together at the respective fused portions to define a continuous layer that extends across all said through holes.   
     
     
         5 . The toothbrush of  claim 2 , further comprising a handle having a head insert opening in which said head insert is mounted. 
     
     
         6 . The toothbrush of  claim 1 , wherein, said bristles are polyester resin bristles. 
     
     
         7 . The toothbrush of  claim 1 , wherein
 each said bristle is tapered only on said first end thereof and further comprises a first non-tapered portion positioned between the tapered first end and the head of the toothbrush; and   in each said bristle:
 the tapered first end has a length of from 4 mm to 8 mm and a tip thickness of 0.01 mm to 0.08 mm; 
 the first non-tapered portion has a thickness of 0.1 mm to 0.2 mm along a length thereof; and 
 a total length of the first non-tapered portion and the tapered first end is from 7 mm to 13 mm. 
   
     
     
         8 . The toothbrush of  claim 7 , wherein
 said bristles comprise first bristles and second bristles;   in each of said first bristles, the tip thickness of the tapered first end is 0.01 to 0.03 mm; and   in each of said second bristles, the tip thickness of the tapered first end is 0.03 to 0.08 mm.   
     
     
         9 . The toothbrush of  claim 7 , wherein, in each of at least some of said bristles, the tip thickness of the tapered first end is 0.01 to 0.03 mm. 
     
     
         10 . The toothbrush of  claim 7 , wherein, in each of at least some of said bristles, the tip thickness of the tapered first end is 0.03 to 0.08 mm. 
     
     
         11 . The toothbrush of  claim 7 , wherein the bristles differ in length by 1 to 10 mm. 
     
     
         12 . The toothbrush of  claim 1 , wherein
 each said bristle is tapered only on said first end thereof, and the tapered first end defines the entire length of the bristle that is exposed outside the head of the toothbrush; and   in each said bristle:
 the tapered first end has a length of 7 mm to 8 mm and a tip thickness of 0.01 mm to 0.08 mm. 
   
     
     
         13 . The toothbrush of  claim 2 , further comprising:
 a toothbrush body;   wherein the fused portions of the bundles of the bristles and the head insert are molded together with the toothbrush body.   
     
     
         14 . The toothbrush of  claim 1 , further comprising:
 a toothbrush body having said head;   wherein the fused second ends of the bristles are directly molded together with the head of the toothbrush body.   
     
     
         15 . A tooth brush made by a method comprising the steps of:
 inserting a plurality of bristles into each of a plurality of through holes defined between an upper surface and a lower surface of a head insert, said lower surface being near to a bottom of the head insert, each of said bristles defining a non-tapered portion at a first end and a tapered portion at a second end opposite to the first end thereof, said non-tapered portion being received into the through hole; and   maintaining the tapered portions of the bristles outside and away from the upper surface of the head insert and the non-tapered portion of the bristles to protrude from the lower surface of the head insert;   thermally fusing the non-tapered portion of the bristles protruding from the lower surface of the head insert, thereby fixing the bristles to the head insert;   attaching the bottom of the head insert to an upper metal mold; combining the upper metal mold with a lower metal mold; and   injecting resin into the lower metal mold through an inlet, thereby attaching the head insert to a head of the toothbrush.   
     
     
         16 . A tooth brush made by a method comprising the steps of:
 inserting a plurality of bristles into each of a plurality of through holes defined between a top part and a bottom part of a lower metal mold, each of said bristles defining a non-tapered portion at a first end and a tapered portion at a second end opposite to the first end, said non-tapered portion being received into the through hole to protrude 2 to 5 mm from the bottom part of the lower metal mold; and   maintaining the tapered portion of the bristles outside and away from the top part of the lower metal mold; thermally fusing the protruded non-tapered portion of the bristles;   combining an upper metal mold with the lower metal mold; and injecting resin into the upper and lower metal molds, thereby fixing the bristles directly to a head of the toothbrush.   
     
     
         17 . A toothbrush, comprising:
 a head; and   a plurality of bristles, each of said bristles comprising a tapered first end exposed outside the head of the toothbrush, and a second, opposite end being placed in the head of the toothbrush,   wherein   the head of the toothbrush further comprises a head insert which comprises
 opposite first and second surfaces, and 
 a plurality of through holes extending from the first surface to the second surface of said head insert; 
   several said bristles are received in each of the through holes to form a bundles of the bristles, with the respective second ends of the bristles protruding beyond the second surface of the head insert and being fused together into a fused portion which is larger than a diameter of the respective through hole; and   at least some of said bundles are also fused together at the respective fused portions to define a continuous layer that extends across the respective through holes in which said at least some bundles are received.   
     
     
         18 . The toothbrush of  claim 17 , wherein
 all of said bundles are fused together at the respective fused portions to define a continuous layer that extends across all said through holes.   
     
     
         19 . The toothbrush of  claim 17 , wherein
 the fused portions of at least some of said bundles are thermally attached to the head insert.   
     
     
         20 . The toothbrush of  claim 17 , wherein
 each said bristle is tapered only on said first end thereof.   
     
     
         21 . The toothbrush of  claim 17 , wherein
 each said bristle is tapered only on said first end thereof and further comprises a first non-tapered portion positioned between the tapered first end and the head of the toothbrush; and   in each said bristle:
 the tapered first end has a length of from 4 mm to 8 mm and a tip thickness of 0.01 mm to 0.08 mm; 
 the first non-tapered portion has a thickness of 0.1 mm to 0.2 mm along a length thereof; and 
 a total length of the first non-tapered portion and the tapered first end is from 7 mm to 13 mm. 
   
     
     
         22 . The toothbrush of  claim 1 , wherein
 said bundles have different shapes selected from the group consisting of rectangle, triangle, circle, oval, and trapezoid.