Medical devices in accordance with various embodiments of the present invention employ one or more coaxial screw gear sleeve mechanisms. In various embodiments, coaxial screw gear sleeve mechanisms include a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing the device to expand.

Medical devices in accordance with various embodiments of the present invention employ one or more coaxial screw gear sleeve mechanisms. In various embodiments, coaxial screw gear sleeve mechanisms include a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing the device to expand.

An improved mechanism for expanding or lifting a device in accordance with various embodiments of the present invention is a coaxial screw gear sleeve mechanism. In various embodiments, coaxial screw gear sleeve mechanisms includes a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing a device utilizing such a mechanism to expand or lift between a collapsed configuration and an expanded configuration.

A screw nut on which a pulley is mounted is capable of promoting reductions in the size and weight thereof. The screw nut includes: an outer ring; and a nut rotatably assembled to the outer ring via a first rolling element. The nut includes: a nut body having a screw groove in an inner surface thereof; and a recirculation component provided at an end portion of the nut body in an axial direction, the recirculation component having a turn-around path for recirculating a second rolling element rolling along a screw groove. A pulley to be mounted on the nut is fitted on an outer surface of the nut body, and is brought into contact with an end surface of the nut in the axial direction. The pulley is mounted on the end surface of the nut with a fastening member.

A screw nut on which a pulley is mounted is provided, the screw nut capable of promoting reductions in the size and weight thereof. A screw nut includes: an outer ring; and a nut rotatably assembled to the outer ring via a first rolling element. The nut includes: a nut body having a screw groove in an inner surface thereof; and a recirculation component provided at an end portion of the nut body in an axial direction, the recirculation component having a turn-around path for recirculating a second rolling element rolling along a screw groove. A pulley to be mounted on the nut is fitted on an outer surface of the nut body, and is brought into contact with an end surface of the nut in the axial direction. The pulley is mounted on the end surface of the nut with a fastening member.

A ballscrew assembly may comprise a ballscrew having an axially distributed ballscrew groove about an interior circumference of the ballscrew, an extended top plate having an axially distributed extended top plate groove disposed on an outer circumference of the extended top plate, and an axially distributed thrust bearing. Further, a ballnut assembly may comprise a ballnut having an axially distributed ballnut groove about an interior circumference of the ballnut, an extended top plate having an axially distributed extended top plate groove disposed on an outer circumference of the extended top plate, and an axially distributed thrust bearing. Further still, a ballnut assembly may comprise a ballnut having an axially distributed ballnut groove about an outer circumference of the ballnut, an extended top plate having an axially distributed extended top plate groove disposed on an interior circumference of the extended top plate and an axially distributed thrust bearing.

Medical devices in accordance with various embodiments of the present invention employ one or more coaxial screw gear sleeve mechanisms. In various embodiments, coaxial screw gear sleeve mechanisms include a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing the device to expand.

Medical devices in accordance with various embodiments of the present invention employ one or more coaxial screw gear sleeve mechanisms. In various embodiments, coaxial screw gear sleeve mechanisms include a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing the device to expand.

An improved mechanism for expanding or lifting a device in accordance with various embodiments of the present invention is a coaxial screw gear sleeve mechanism. In various embodiments, coaxial screw gear sleeve mechanisms includes a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing a device utilizing such a mechanism to expand or lift between a collapsed configuration and an expanded configuration.

An improved mechanism for expanding or lifting a device in accordance with various embodiments of the present invention is a coaxial screw gear sleeve mechanism. In various embodiments, coaxial screw gear sleeve mechanisms includes a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing a device utilizing such a mechanism to expand or lift between a collapsed configuration and an expanded configuration.