Toothbrush with a replaceable function part

Abstract

A toothbrush includes a handle and a function part. The handle includes an installation end in which an insertion hole is defined axially. An opening is defined through the wall of the installation end and communicates with the insertion hole. A guiding groove is formed axially in the inside of the insertion hole. The function part includes a head with bristles, and an insertion which extends from one end of the head and has a through hole defined therethrough. A spring member is secured in the through hole and includes a protrusion. The insertion is inserted into the insertion hole of the handle, and the protrusion is movably engaged with the guiding groove until the protrusion is engaged with the opening when the insertion is positioned in the insertion hole. The spring member is not deformed when the protrusion moves along the guiding groove.

What is claimed is: 
     
         1 . A toothbrush comprising:
 a handle having an installation end and a grip end respectively formed on two ends thereof, the installation end having an insertion hole defined axially therein, an opening defined through a wall of the installation end and communicating with the insertion hole, a guiding groove formed axially in an inside of the insertion hole, and   a function part having a head and an insertion that extends from one end of the head, the insertion including a through hole defined therethrough, a spring member secured in the through hole and having a protrusion, the insertion inserted into the insertion hole of the handle and the protrusion movably engaged with the guiding groove, the spring member being not deformed when the protrusion moves along the guiding groove, the protrusion engaged with the opening when the insertion is positioned in the insertion hole.   
     
     
         2 . The toothbrush as claimed in  claim 1 , wherein an inclined face is formed between the guiding groove and the opening, the spring member is deformed when the protrusion moves along the inclined face, the protrusion is engaged with the opening when the protrusion separates from the inclined face. 
     
     
         3 . The toothbrush as claimed in  claim 1 , wherein the opening includes two restriction faces that are located on two insides of the opening, a positioning face is formed between the two restriction faces and located close to the inclined face, the protrusion contacts the two restriction faces and the positioning face when the protrusion is engaged with the opening. 
     
     
         4 . The toothbrush as claimed in  claim 3 , wherein the function part includes a tongue which is located at a conjunction portion between the insertion and the head, a notch is defined in the installation end of the handle and communicates with the insertion hole, the tongue is engaged with the notch when the insertion is positioned in the insertion hole. 
     
     
         5 . The toothbrush as claimed in  claim 4 , wherein the insertion includes at least one restriction member extending therefrom and the at least one restriction member is located between two inside surfaces of the guiding groove to restrict the insertion from rotating relative to the handle. 
     
     
         6 . The toothbrush as claimed in  claim 5 , wherein the at least one restriction member is located between the head and the through hole. 
     
     
         7 . The toothbrush as claimed in  claim 5 , wherein the at least one restriction member is an elongate block.