Rotary actuator

A rotary actuator comprising:

• a shaft;
• a first threaded portion and a second threaded portion formed on the shaft and axially spaced from each other;
• a first nut mounted for movement along the first threaded portion;
• a second nut mounted for movement along the second threaded portion;
• a plurality of first components extending radially outward from the first nut;
• a plurality of second components extending radially outward from the second nut;
• an earth sleeve extending around the shaft and the first and second nuts;
• and
• an output sleeve extending around the shaft and the first and second nuts;
• wherein the shaft is configured to be driven to rotate about a longitudinal axis thereof relative to the earth sleeve;
• wherein the earth sleeve comprises a plurality of axially extending earth guides;
• wherein the output sleeve comprises a plurality of first guides and a plurality of second guides;
• wherein each first component engages with a respective first guide and a respective earth guide for movement there along;
• wherein each second component engages with a respective second guide and a respective earth guide for movement there along;
• wherein the first and second threaded portions are threaded so as to cause the first and second nuts to move along the shaft in opposite directions to each other on rotation of the shaft;
• and
• wherein the plurality of first guides and the plurality of second guides are configured such that movement of the plurality of first and second components along the respective guides as the shaft rotates drives rotation of the output sleeve.