High acceleration spindle drive and method of using same

A spindle driving assembly comprising:

• a spindle;
• a spindle drive member mounted for movement from a first position to a second position through a range of movement;
• a first spring pressing on the spindle either directly or indirectly with a first force;
• a second spring pressing a second force on the spindle in the spindle driving assembly either directly or indirectly;
• and
• a stop element arranged to disengage the force of the of the second spring so that when the drive member is within a first portion of the range of movement, the first spring and the second spring press forces on the spindle and when the drive member is in a second portion of the range of movement, the stop element disengages the force applied by the second spring on the spindle;
• wherein movement of the drive member drives the spindle.

A method of moving a spindle along a longitudinal axis, the method comprising:

• moving said spindle with acceleration during a first portion of a range of travel along said longitudinal axis;
• moving said spindle with deceleration during a second portion of a range of travel along said longitudinal axis,
• applying a first force and a second force to the spindle, either directly or indirectly, during the spindle acceleration in order to counter any resistance of the spindle to the acceleration;
• disengaging the second force;
• and
• applying only the first force to the spindle, either directly or indirectly, during the spindle deceleration.