PRESSURE-BOOSTING DENTAL SYRINGE

摘要

The syringe is suitable esp. for ligaments between jawbone and tooth where partic. high injection pressure is required. The syringe has an injection needle(7), leading from a supply chamber(5), and a plunger(12) which is moved to displace the chamber base and expelling. A rack(15) integral with the plunger is engaged by a ratchet(19) whic is pivoted (20) on a thumb lever (3) itself pivoted (16) on the syringe body(2). A pivoted (24) rocker(23) is spring- loaded(27) to engage the rack with a nonreturn pawl(25) except when a release button (26) is pressed. The mechanism provides a mechanical advantage of about 5:1 to reduce thumb lever effort.