| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a medical instrument removable by a carpule for use in a retractable dental syringe. <P>SOLUTION: This retractable instrument 10 releases a fluid from the carpule. A retractable mechanism 20 having a spring-energized needle holder 22 with a double-ended needle 28 is mounted in the front of a housing 12 by a push ring 40 slidably mounted on an enlarged part of the holder. The outer edge of the push ring is held or regulated by the inner wall surface to hold the needle holder in a predetermined position, and the carpule disposed through a rear opening of the housing is gradually supported on a plunger. The plunger unloads medicine from the carpule through the needle to move a piston composed of two separable parts. At the end of an injection, the plunger is again depressed to remove the push ring in cooperation with the carpule so that the needle holder becomes retractable through a front opening of the carpule. When the needle is drawn in the housing from one end, the edge of a thumb cap disappears in an opening at the opposite end of the housing. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
