Tooth percussion instrument

Claim 1

A dental instrument for the application of measured percussion to a tooth surface, the instrument comprising: an elongated housing dimensioned for application to a tooth within a mouth and including separable barrel sections each having a passageway therein; an elongated plunger mounted for movement within the passageways and having a handle end and a force application tip; a series of graduated stops on the plunger, each stop comprising a substantially conical body portion having a perpendicular shoulder and a cam wall extending in the direction of the handle end of the plunger; the housing having an elongated, longitudinally extending slot formed therein, and having indicia thereon adjacent said slot; a coil spring about the plunger and a collar on the plunger engaging the spring to compress the same upon inward movement of the plunger responsive to withdrawal of the handle outwardly of the housing; the collar having an extension thereon projecting through the slot and observable relative to the indicia; and catch means on the housing to selectively engage the graduated stops upon movement of the plunger in said inward direction and to release the plunger upon actuation, said catch means comprising a pivotal lever having an outer button and a pawl extending into the housing to engage the shoulders of the stops, depression of the button serving to pivot the pawl out of contact with the shoulder and to release the plunger.