An actuator (10) is provided comprising a motor shaft (12) having an axis (X), an output (18) arranged to rotate within an angular range of less than 360 degrees, wherein rotation of the motor shaft about the axis drives the output in rotation, a first ratchet (26) comprising a first ratchet wheel (261) and a first ratchet pawl (262), the first ratchet arranged such that, while the first ratchet pawl engages the first ratchet wheel, the first ratchet wheel is freely rotatable in a first direction and prevented from rotation in a second direction, opposite the first direction; and a second ratchet (28) comprising a second ratchet wheel (281) and a second ratchet pawl (283), the second ratchet arranged such that, while the second ratchet pawl engages the second ratchet wheel, the second ratchet wheel is freely rotatable in the second direction and prevented from rotation in the first direction. The first and second ratchet wheels are mounted to a shaft (30). A first cam surface is (264) connected to rotate with the output (18), wherein the first cam surface is arranged to disengage the first ratchet pawl from the first ratchet wheel when the output is within a first predetermined angular range, and to allow the first ratchet pawl to engage with the first ratchet wheel when the output is outside the first predetermined angular. A second cam surface (284) is connected to rotate with the output (18), wherein the second cam surface is arranged to disengage the second ratchet pawl from the second ratchet wheel when the output is within a second predetermined angular range, and to allow the second pawl to engage with the second ratchet wheel when the output is outside the second predetermined angular range. An electrically-actuated clutch (22) arranged to selectively connect the shaft to the motor shaft. The ratchets brake the shaft against rotation in either direction when the output is not within either of the predetermined ranges. Thus, when the motor shaft is connected, via the clutch, to the shaft, the ratchets may act as a brake on the motor shaft.
RUNAWAY EMERGENCY ACTUATOR BRAKE
ACTIONNEUR DE FREIN DE DETRESSE EN SITUATION DE PERTE DE CONTROLE
2023-10-06
Patent
Elektronische Ressource
Englisch
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