Patent ID: 7701228
Filing Date: 2010-04-20
Classification: G01R

Abstract:
1. A nuclear magnetic resonance apparatus comprising: a radio-frequency nuclear magnetic resonance coil; a variable capacitor electrically connected to the radio-frequency coil; and a switchable manual-mode/motor-driven mode tuning assembly coupled to the variable capacitor, for adjusting a capacitance of the variable capacitor, comprising an axially-rotatable longitudinal tuning shaft coupled to the variable capacitor; a manual control coupled to the tuning shaft when the tuning assembly is in a manual mode, for manually rotating the tuning shaft to adjust the capacitance of the variable capacitor; a tuning motor coupled to the tuning shaft when the tuning assembly is in a motor-driven mode, and de-coupled from the tuning shaft when the tuning assembly is in the manual mode, for driving a rotation of the tuning shaft to adjust the capacitance of the variable capacitor; and a mode-switching coupler coupling the tuning motor to the tuning shaft when the tuning assembly is in the motor-driven mode, the coupler comprising a first coupler terminal connected to the tuning motor and a second coupler terminal connected to the tuning shaft, wherein in the motor-driven mode the first coupler terminal is coupled to and drives an axial rotation of the second coupler terminal, and wherein in the manual mode the first coupler terminal is longitudinally separated from and rotationally-decoupled from the second coupler terminal.