Telescopic ballscrew actuator

A method of operating an actuator of an aircraft, comprising:

• in a first mode, rotating an input shaft of the actuator about an axis to cause a first component to translate along the axis due to operation of a first ballscrew mechanism so that the first component telescopically protrudes and extends from the input shaft;
• in a second mode, rotating the first component about the axis to cause a second component to translate along the axis due to operation of a second ballscrew mechanism so that the second component telescopically protrudes and extends from the first component;
• and
• wherein the first mode occurs prior to the second mode and transitioning between the first mode and the second mode by a stop fixedly attached to the first component abutting a stop attached to the input shaft to limit the stroke of the first component, thereby preventing further translation of the first component such that further rotational movement of the input shaft causes the first component to start rotating and the second component to translate along the axis due to operation of the second ballscrew mechanism.

An actuator for use in an aircraft, the actuator comprising:

• an input shaft;
• a first component located concentrically around the input shaft;
• a first ballscrew mechanism between the input shaft and the first component, and configured such that in a first mode rotational movement of the input shaft passes a load to the first component via the first ballscrew mechanism , wherein the load overcomes frictional forces between the input shaft, the first component and the first ballscrew mechanism, so as to cause a translational movement of the first component via the first ballscrew mechanism;
• characterised in that the actuator comprises:
• a second component located concentrically around the first component;
• and
• a second ballscrew mechanism between the first component and the second component, and configured such that in a second mode rotational movement of the input shaft passes a load to the first component via the first ballscrew mechanism, wherein the load does not overcome frictional forces between the input shaft, the first component and the first ballscrew mechanism so as to cause a rotational movement of the first component which passes the load to the second ballscrew mechanism and so causes a translational movement of the second component via the second ballscrew mechanism,
• wherein in the first mode the first component is configured to translate along an axis upon rotational movement of the input shaft, and in the second mode the first component is configured to rotate about the axis, wherein an operational sequence of the first mode and the second mode is caused by said frictional forces between the input shaft, the first component and the first ballscrew mechanism.

A method of operating an actuator of an aircraft, comprising:

• in a first mode, rotating an input shaft of the actuator about an axis to pass a load to a first component via a first ballscrew mechanism, the load overcoming frictional forces between the input shaft, the first component and the first ballscrew mechanism so as to cause the first component to translate along the axis due to operation of the first ballscrew mechanism;
• and
• in a second mode, rotating the input shaft to pass a load to the first component via the first ballscrew mechanism, wherein the load does not overcome frictional forces between the input shaft, the first component and the first ballscrew mechanism thereby rotating the first component about the axis to cause a second component to translate along the axis due to operation of a second ballscrew mechanism,
• wherein an operational sequence of the first mode and the second mode is caused by relative frictional forces between the first ballscrew mechanism and the second ballscrew mechanism.