Self-compensating tunable bridge for string musical instrument

摘要

A tunable bridge for a string musical instrument is provided to enable a user to rapidly switch between two pre-selected string tunings simply by movement of an actuator arm. The actuator arm controls the position of a cam roller assembly, which in turn controls the pivotal movement of a rocker arm between a lower position and an upper position. A multiplicity of string fingers are mounted for pivotable movement between respective first and second tuning positions. A plurality of manually-adjustable tuning screws with engagement tips are threadedly disposed in the rocker arm. Each engagement tip is configured to press against a respective string finger when the rocker arm is placed in its upper position, thereby further stretching the strings attached to the respective string fingers and increasing their pitch in accordance with the second pre-selected tuning. Mounting of the tunable bridge does not require permanent modification of the string instrument.

主权项

1. A tunable bridge for a string musical instrument, said tunable bridge comprising:
a base plate securable to said string musical instrument; a rocker arm having a proximal portion, a distal portion and a rocker axis therebetween, said rocker arm being mounted for pivoting movement with respect to said base plate about said rocker axis between a lower position and an upper position; a cam roller fork mounted for rotational movement with respect to said distal portion about a cam axis between a lock position and a release position; a cam roller mounted to said cam roller fork and configured to contact said base plate for translational movement relative thereto when said cam roller fork is moved between its lock and unlock positions; an actuator arm actuatable about said cam axis between a first arm position and a second arm position; a multiplicity of string fingers, each said string finger having a tuning interface portion, a ball detent portion and a finger axis therebetween, each said string finger being mounted for pivotable movement with respect to said base plate about its finger axis between a first tuning position and a second tuning position; and a plurality of tuning screws, each said tuning screw having an engagement tip and being threadedly disposed in said proximal portion for adjustable placement of said engagement tip at a respective axial distance therefrom, each of said engagement tips being configured to pressingly engage a respective said tuning interface portion.