| 摘要 |
The purpose of the present invention is to provide a dental handpiece that can, on the basis of a simple and inexpensive configuration, precisely prevent fall off of a cover body due to the loosening of the screw attachment of the cover body which is screw-connected to a handpiece head part. The present invention provides a dental handpiece (1) which comprises a cartridge housing (21) that detachably holds therein a rotationally driven cutting tool (22) and that is disposed inside of an accommodation region (4) of a handpiece head part (2), wherein: a screw connection is established between a male screw thread (16) of a cover body (11) which is screwed onto the handpiece head part (2) and a female screw thread (6) of the handpiece head part (2); a first recessed groove (15) that enables free fitting of the inner circumferential-section side of a C-ring (17), which is a ring-shaped elastic member, is provided at a male screw-thread end section provided to a peripheral wall part (12) of the cover body (11); a second recessed groove (5) that accommodates the outer circumferential-section side of the C-ring (17) and that is disposed opposing the first recessed groove (15) when the cover body (11) is screwed onto the handpiece head part (2) is provided at a female screw-thread advancement section provided to the handpiece head part (2); and a contact resistance force is generated by the C-ring (17) when the screw attachment of the cover body (11) becomes loose, thereby preventing the fall off of the cover body (11). |
