| 摘要 |
<p>PURPOSE: To freely select a ratio of input torque to output torque by controlling the output torque of a driving electric motor at output torque corresponding to manual input torque. CONSTITUTION: Armature current can change the resistance of a variable resistor 16 in response to torque generated with a foot pedal. At the same time, current flowing across the resistor 16 from a power supply and a pole 12a via an electrical switch 12c varies, due to the manual selection of a selector switch turning lever 41 for slidable contact with terminals 41a, 41b and so forth, thereby changing the armature current correspondingly. In this case, maximum current flows, when the lever 41 comes in contact with the terminal 41a, and a current value is reduced in the order of the terminals 41b, 41c and so forth. According to this construction, the lever 41 is manually selected for changing the armature current, when torque due to the foot pedal is equal to the preset value, thereby increasing or decreasing the output torque of an electric motor 34.</p> |
