A lift device comprises a base, a retractable lift mechanism, a work platform, a linear actuator, and a lift controller. The retractable lift mechanism has a first end coupled to the base and is moveable between an extended position and a retracted position. The work platform is coupled to and supported by a second end of the retractable lift mechanism. The linear actuator is configured to selectively move the retractable lift mechanism between the extended position and the retracted position. The linear actuator comprises a central screw rod, an electric motor configured to provide rotational actuation to the central screw rod, and a nut assembly configured to translate the rotational actuation of the central screw rod into linear motion. The lift controller is configured to receive a lift command from an operator, monitor at least one lift characteristic associated with the linear actuator, and selectively inhibit the lift command.

An electric fail-safe actuator includes a speed reducer/gear assembly housing arranged between one or more electric motors, and a rotation to linear transformer including a roller or ball nut and a screw, or a nut and a roller or ball screw. The speed reducer/gear assembly housing is connected to an actuator housing via a counter hold release mechanism, allowing the speed reducer/gear assembly housing to co-rotate with a rotational side of the rotation to linear transformer when the counter hold release mechanism is released.

A jam free linear actuator system includes a linear electro-mechanical actuator configured to actuate a component; a disengagement mechanism configured to disengage components of the linear electro-mechanical actuator in an event of a jammed failure; a fixed end fitting mechanical connection; and a trim end fitting mechanical connection. The fixed end fitting mechanical connection connects the linear electro-mechanical actuator to a portion of a system implementing the linear electro-mechanical actuator; and the trim end fitting mechanical connection connects the linear electro-mechanical actuator to the component.

There is provided an actuator comprising screw shaft and a nut assembly. The nut assembly comprises a primary nut for transmitting load through the actuator along a primary load path, and a secondary nut for transmitting load through the actuator along a secondary load path. The secondary nut comprises first and second portions movable relative to one another. As load is transmitted through the actuator along the primary load path the secondary nut does not transmit load through the actuator, wherein upon failure of the primary load path the first and second portions move relative to each other, such relative movement causing the first and second portions to engage the screw shaft and enable transmittal of load through the secondary nut of the actuator along the secondary load path.

A ball screw assembly for use in an actuator is provided. The ball to screw assembly may include a ball screw supported for rotation by the actuator. A ball nut may be provided around the ball screw and may be held against rotation with the ball screw by said actuator. A primary load path may be provided between the ball screw and the ball nut for operatively coupling the ball nut with the ball screw. A secondary load path may be provided between the ball screw and the ball nut, wherein the secondary load path can be disengaged during a normal operating mode of the ball screw assembly and the secondary load path can be engaged during a second operating mode of the ball screw assembly.

A lift device comprises a base, a retractable lift mechanism, a work platform, a linear actuator, and a lift controller. The base has a plurality of wheels. The retractable lift mechanism has a first end coupled to the base and is moveable between an extended position and a retracted position. The work platform is configured to support a load. The work platform is coupled to and supported by a second end of the retractable lift mechanism. The linear actuator is configured to selectively move the retractable lift mechanism between the extended position and the retracted position. The lift controller is configured to monitor at least one lift characteristic associated with the linear actuator and to determine whether an actuator failure has been detected based on the at least one lift characteristic associated with the linear actuator.

A medical device drive system including a lever body having portions defining a lever body cavity, a nut housing in the lever body cavity, and a first nut at least partially in the first nut cavity. The first nut is slideable in the first nut cavity between an engaged position in which the lead screw interface is engaged with the engagement portion of the lead screw, and a disengaged position in which the lead screw interface is not engaged with the engagement portion of the lead screw. The lead screw interface of the first nut is selectively engageable with the engagement portion of the lead screw by sliding the lever body and pin relative to the first nut housing.

A lift device comprises a base, a retractable lift mechanism, a work platform, a linear actuator, and a lift controller. The retractable lift mechanism has a first end coupled to the base and is moveable between an extended position and a retracted position. The work platform is coupled to and supported by a second end of the retractable lift mechanism. The linear actuator is configured to selectively move the retractable lift mechanism between the extended position and the retracted position. The linear actuator comprises a central screw rod, an electric motor configured to provide rotational actuation to the central screw rod, and a nut assembly configured to translate the rotational actuation of the central screw rod into linear motion. The lift controller is configured to receive a lift command from an operator, monitor at least one lift characteristic associated with the linear actuator, and selectively inhibit the lift command.

There is provided an actuator comprising screw shaft and a nut assembly. The nut assembly comprises a primary nut for transmitting load through the actuator along a primary load path, and a secondary nut for transmitting load through the actuator along a secondary load path. The secondary nut comprises first and second portions movable relative to one another. As load is transmitted through the actuator along the primary load path the secondary nut does not transmit load through the actuator, wherein upon failure of the primary load path the first and second portions move relative to each other, such relative movement causing the first and second portions to engage the screw shaft and enable transmittal of load through the secondary nut of the actuator along the secondary load path.

An actuator includes a drive assembly, a ball screw, and a ball nut. The ball nut may include a first nut member, a second nut member; and first arm extending from the first nut member. The first arm may include a first portion and a second portion. The first portion may extend radially outward from the first nut member. The second portion may extend substantially axially from the first portion such that at least some of the second portion is disposed radially outward of the second nut member. A second arm may extend from the second nut member, and the second arm may include a first portion and a second portion. In embodiments, at least part of the second portion of the first arm is disposed radially outward of at least a part of the second portion of the second arm.