Failsafe module

A failsafe module comprising:

• an input member;
• an output member movable toward and away from a predetermined position;
• a coupling mechanism for coupling the input member to the output member, the coupling mechanism comprising:
• an intermediate member engaged with the input member and movable by the input member between a first position and a second position;
• an energy storage device acting between the output member and the intermediate member, such that movement of the intermediate member relative to the output member from the first position to the second position energizes the energy storage device, and wherein the energy storage device, the output member, and the intermediate member are engaged such that a release of energy from the energy storage device drives the output member to the predetermined position;
• and
• a latch mechanism having an engaged state in which the latch mechanism prevents relative movement between the intermediate member and the output member when the intermediate member is in the second position, to thereby hold the energy storage device in an energized state and to thereby couple the input member to the output member, and the latch mechanism having a released state in which the latch mechanism allows relative movement between the intermediate member and the output member, to thereby allow the energy storage device to be energized or to release energy;
• wherein the latch mechanism comprises a first latch member and a second latch member, wherein the first latch member and the second latch member are configured to couple when the intermediate member is in the second position;
• and wherein the latch mechanism further comprises a clutch assembly configured to couple the input member to the output member when the latch mechanism is in the engaged state;
• wherein:
• the latch mechanism comprises the first latch member on the output member and the second latch member on the intermediate member;
• the input member is coupled to the output member via the intermediate member;
• the energy storage device is configured to apply a torque between the intermediate member and the output member;
• rotational movement of the intermediate member relative to the output member from the first position to the second position energises the energy storage device;
• and
• the latch mechanism, in the engaged state, prevents relative rotational movement between the intermediate member and the output member, and, in the released state, allows relative rotational movement between the intermediate member and the output member;
• and further comprising a drive arrangement arranged between the intermediate member and the output member, the drive arrangement comprising:
• a first drive element rotatable relative to the intermediate member;
• and
• a second drive element rotationally fixed relative to the output member and in engagement with the first drive element;
• wherein:
• the energy storage device is engaged between the first drive element and the intermediate member;
• and
• the intermediate member, the drive arrangement and the output member are engaged such that relative rotational movement between the intermediate member and the output member causes relative rotational movement between the intermediate member and the first drive element to thereby energise the energy storage device.

A failsafe module comprising:

• an input member;
• an output member movable toward and away from a predetermined position;
• a coupling mechanism for coupling the input member to the output member, the coupling mechanism comprising:
• an intermediate member engaged with the input member and movable by the input member between a first position and a second position;
• an energy storage device acting between the output member and the intermediate member, such that movement of the intermediate member relative to the output member from the first position to the second position energizes the energy storage device, and wherein the energy storage device, the output member, and the intermediate member are engaged such that a release of energy from the energy storage device drives the output member to the predetermined position;
• and
• a latch mechanism having an engaged state in which the latch mechanism prevents relative movement between the intermediate member and the output member when the intermediate member is in the second position, to thereby hold the energy storage device in an energized state and to thereby couple the input member to the output member, and the latch mechanism having a released state in which the latch mechanism allows relative movement between the intermediate member and the output member, to thereby allow the energy storage device to be energized or to release energy;
• an outer housing containing at least the input member and the output member, so that the outer housing, input member and output member are co-axial;
• whereby the outer housing comprises an aperture co-axial with the input member and through which a portion of the input member extends;
• and whereby a circumferential wall extends axially away from the outer housing around the aperture;
• an actuator having an actuator housing which houses a drive mechanism;
• the actuator is mountable to the outer housing and configured to engage with the input member, such that the input member is rotatable by the drive mechanism;
• and,
• a safety mechanism configured to prevent relative rotation between the actuator housing and the outer housing when the actuator is separated from the outer housing;
• the safety mechanism comprising:
• a cover comprising a surface portion and a skirt portion, whereby the skirt portion extends around an edge of and axially away from the surface portion;
• and whereby the cover is mounted to the actuator housing via the surface portion, and removably mountable to the outer housing via the skirt portion;
• the cover is configured such that the skirt portion engages with the circumferential wall of the outer housing when the actuator is mounted to the outer housing, so that the cover and the outer housing are co-axial about the common axis;
• an interlock mechanism configured to act between the circumferential wall of the outer housing and the skirt portion of the cover, such that the actuator housing and outer housing are rotationally fixed when the skirt portion of the cover is engaged with the circumferential wall of the outer housing;
• and,
• a connector rotationally fixed to the drive mechanism, such that operation of the drive mechanism causes rotation of the connector;
• and wherein the connector and the cover are co-axial about the common axis;
• wherein:
• the connector comprises a protruding leg, which extends axially away from the connector when the actuator is mounted to the outer housing;
• the portion of the input member extending through the aperture in the outer housing is configured to receive the protruding leg of the connector when the actuator is mounted to the outer housing, thereby rotationally fixing the connector and the input member, so that operation of the drive mechanism causes corresponding rotation of the input member via the connector;
• and,
• the length of the skirt portion of the cover is longer than the length of the protruding leg of the connector, so that the protruding leg of the connector disengages from the input member before the skirt portion of the cover disengages from the wall of the outer housing when the actuator is separated from the outer housing, so that the actuator housing and the outer housing remain rotationally fixed by the interlock mechanism until the skirt portion of the cover is completely disengaged from the wall of the outer housing.