| 摘要 |
The present invention provides a hinge tube which is disposed in a musical instrument to connect to keys and valves of the musical instrument. The hinge tube forms at least one recess portion on a periphery of the hinge tube. Thereby, the positions on which the valves and the keys disposed are able to be identified easily, and the valves and the keys are fixed to the hinge tube more firmly to improve the stability of the musical instrument. |
