An actuator device includes a housing, parallel rolling screws supported in the housing, an actuator element, an actuator spindle anchored in the actuator element, a control system, sensor heads, and position sensors. Each rolling screw is coupled to an electric motor and engages a roller nut. Rotating the rolling screws axially displaces the rolling nuts. The actuator element engages with each rolling nut. One sensor head is arranged on the actuator element near each roller nut. One position sensor is fastened in the actuator adjacent each sensor head and communicates position information of each sensor head to the control system. Each electric motor has an encoder coupled to the control system. The encoder provides a primary motor control. The control system compares information from each position sensor with information from the encoder. The information from each position sensor acts as a secondary position control of the actuator element.

A gear selection and shifting actuating mechanism and a gear selection and shifting actuating method, the actuating mechanism comprising a gear shifting motor, a first transmission gear, second transmission gears, gear shifting screws, a push block, a shift fork, a shift block and a linear driving device. An output shaft of the gear shifting motor is provided thereon with the first transmission gear; the first transmission gear is engaged with the second transmission gears; the second transmissions gears are fixedly connected to the gear shifting screws; the gear shifting screws are in screw thread connection with the push block; the push block is provided thereon with a through hole; one end of the shift block is connected to the linear driving device, and the other end is aligned with a groove on the shift fork after inserting into the through hole. The linear driving device that corresponds to a shift position drives the shift block to be inserted into the shift fork so as to shift gears; the gear shifting motor drives the first transmission gear to rotate and thus drives the second transmission gears to rotate; the second transmission gears drive the gear shifting screws to rotate and drive the push block to move; and the push block shifts the shift fork by means of the shift block to shift gears.

An electrically actuated parking brake has a single electric motor producing a torque, a first torque limiting device with a first spring force, and a second torque limiting device with a second spring force. The first torque limiting device fully transmits a first portion of the torque to a first spindle until a first clamp force overcomes the first spring force and the second torque limiting device fully transmits a second portion of the torque to a second spindle until a second clamp force overcomes the second spring force. When the first clamp force overcomes the first spring force and the second spring force overcomes the second clamp force, the first portion of the torque that exceeds the first spring force is transmitted to the second spindle by the second torque limiting device.

An actuator is for use in petroleum exploitation and is configured for displacing a rod for engaging a well barrier device. The actuator has a housing for at least a portion of the rod; at least two roller screws rotatably arranged in the housing; rotational means connected to the roller screws via one gear systems for each roller screw for simultaneous rotation of the roller screws; and a roller nut engaging each roller screw. The roller screws and roller nuts are configured such that rotation of the roller screws result in displacement of the roller nuts relative to the roller screws. Each roller nut is coupled with one actuation element via spherical bearings, and each actuation element is configured for mechanical coupling to an end portion of the rod for displacing the rod in operational use.

A shower caddy for attachment to an associated outer enclosure panel or door of an associated shower or tub enclosure includes a body and an attachment mechanism mounted on an end portion of the body. The attachment mechanism has at least one movable mounting arm. The attachment mechanism is configured such that downward movement of the body relative to the attachment mechanism by force of gravity moves the at least one mounting arm from a rest position toward an engagement position where the at least one mounting arm is engageable with the associated outer enclosure panel or door.

The multiple small pitch helical drives in linear and rotary actuators uses a plurality of small pitch helical screws in place of a single large pitch lead screw to provide increased power or force in a linear actuator or increased torque in a rotary actuator. The multiple small pitch helical drive includes a plurality of screws disposed between a base panel and a rear panel in a rigid skeleton, the screws having a single degree of freedom, i.e., they are free to rotate, but cannot move axially. A piston head having spaced disks includes floating nuts disposed in sockets on the disks for each of the screws, the piston head being free to travel on the screws between the base panel and the rear panel as the screws are rotated. The helical pitch reduction provided results in increased force output and increased torque for linear and rotary actuators.

A gearbox assembly of a surgical instrument and a surgical instrument including the same are provided. The gearbox assembly includes a carriage configured to selectively translate, four gear systems each including an input portion configured to receive an input and an output portion configured to provide an output, a first differential gear assembly operably coupled between the first and second gear systems, a second differential gear assembly operably coupled between the third and fourth gear systems, and a third differential gear assembly operably coupled between the first and second differential gear assemblies. The third differential gear assembly including an output coupled to the carriage. In response to different inputs provided, the third differential gear assembly provides no output to the carriage. In response to equal inputs provided, the output of the third differential gear assembly translate the carriage.

An linear actuator drive arrangement is disclosed that includes a drive screw including a drive screw threading on an outer periphery thereof and a first axial end of the drive screw is configured to support a load. The arrangement includes a motor including a stator and a rotor arranged radially within the stator. The rotor includes a rotor housing, a first ring nut, and a second ring nut. A plurality of planetary screws are arranged radially between the drive screw and the first ring nut and the second ring nut. A bearing assembly is arranged radially inside a first axial end of the rotor housing, and the bearing assembly axially supports the rotor housing. An encoder ring is fixed to a radially outer surface of the rotor housing at the first axial end of the rotor housing, and the encoder ring is concentric with the bearing assembly.

A linear actuator comprising a housing with a proximal end and a distal end, and defining a central cavity extending axially; a piston tube at least partially positioned axially within the central cavity; a first elongated rotatable screw positioned axially within the central cavity; a first cylindrical nut mounted about the first elongated rotatable screw and configured to move axially as the first elongated rotatable screw rotates; a second elongated rotatable screw positioned axially within the central cavity; a second cylindrical nut mounted about the second elongated rotatable screw and configured to move axially within the central cavity as the second elongated rotatable screw rotates; and a spring positioned around the second elongated rotatable screw between the second cylindrical nut and the distal end of the housing, wherein the spring is configured to bias the second cylindrical nut away from the distal end of the housing.

An electric booster includes an input member configured to be moved forward or rearward according to an operation on a brake pedal, a thrust force transmission member provided movably relative to the input member, an electric actuator configured to move the thrust force transmission member forward or rearward, and an output member connected to the thrust force transmission member and configured to transmit a thrust force provided from the electric actuator to the thrust force transmission member to a piston of a master cylinder. The electric actuator includes an electric motor, at least two threaded shaft members configured to be rotationally driven by the electric motor, and nut members respectively meshed with the threaded shaft members. Each of the nut members is connected to the thrust force transmission member. The thrust force transmission member is swingably connected to at least one of the nut members and the output member.