Disposable prophylaxis angle with improved gear retainer

Abstract

An example method of assembling a prophylaxis angle includes inserting a drive gear into a first axial bore defined within a neck of an angle body, the drive gear having a drive gear head and a locking flange axially-offset from the drive gear head. A driven gear is inserted into a second axial bore defined within a head of the angle body, the first and second axial bores being angularly-offset from each other and communicating at an intersection in the angle body. The body defines an opening that spans contiguous portions of both the neck and the head. The drive gear is coupled to the driven gear such that rotation of one rotates the other. A gear retainer is then installed on the head, the gear retainer having an annular body that defines an inner circumferential surface that extends about an outer surface of the head.

What is claimed is: 
     
         1 . A method of assembling a prophylaxis angle, comprising
 inserting a drive gear into a first axial bore defined within a neck of an angle body, the drive gear having a drive gear head and a locking flange axially-offset from the drive gear head;   inserting a driven gear into a second axial bore defined within a head of the angle body, the first and second axial bores being angularly-offset from each other and communicating at an intersection in the angle body, the body defining an opening that spans contiguous portions of both the neck and the head;   operatively coupling the drive gear to the driven gear such that rotation of one rotates the other; and   installing a gear retainer on the head, the gear retainer having an annular body that defines an inner circumferential surface that extends about an outer surface of the head, a heel extending from the annular body, an arm extending from the heel, and a wedge extending from the arm.   
     
     
         2 . The method of  claim 1 , wherein installing the gear retainer on the head further comprises receiving at least one protrusion defined on the outer surface of the head into an aperture at least partially defined in a flange extending from the annular body. 
     
     
         3 . The method of  claim 2 , further comprising:
 engaging the flange on a beveled surface defined by the at least one protrusion; and   flexing the flange on the beveled surface such that the at least one protrusion is able to be received within the aperture.   
     
     
         4 . The method of  claim 1 , wherein the gear retainer further comprises a locking mechanism offset from the wedge and also extending from the arm, and wherein installing the gear retainer on the head further comprises:
 angularly aligning the heel and the arm with the opening;   occluding the opening with the heel and the arm; and   receiving the locking flange between the wedge and the locking mechanism, thereby preventing axial displacement of the drive gear within the first axial bore.   
     
     
         5 . The method of  claim 4 , wherein the locking mechanism comprises a beveled surface and a locking surface, the method further comprising:
 flexing the locking mechanism as the beveled surface engages the neck at the opening;   snapping the locking mechanism into place at the opening; and   engaging an inner surface of the first axial bore with the locking surface, thereby preventing the gear retainer from removal from the opening.   
     
     
         6 . The method of  claim 1 , further comprising ultrasonically-welding the gear retainer to the head. 
     
     
         7 . The method of  claim 1 , wherein installing the gear retainer on the head further comprises receiving one or more retainer protrusions defined on the inner circumferential surface of the gear retainer into an arcuate groove defined about at least a portion of the outer surface of the head.