摘要:
Improved methods and apparatuses for vertebral body distraction and fusion 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 distract.
摘要:
Improved methods and apparatuses for vertebral body distraction and fusion 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 distract.
摘要:
A linear actuation system has two linear actuator channels acting in tandem and a gear housing connecting the two actuator channels and providing an output for the actuation system. The gear housing has multiples gears with at least one gear connected to each actuator and is movable.
摘要:
An under travel actuator, particularly intended for an automobile clutch, including an engine (12) for the translation movement of a mobile gear (14) acting on a push stem (16) for the opening and closing of the clutch, the mobile gear including screw-nut means (22, 24) cooperating with two combined means of unidirectional driving in order to regulate the length of the push stem (16) according to the wear of the clutch surfaces subject to friction.
摘要:
The present invention concerns a linear actuator (1), comprising a threaded spindle (10) with a longitudinal extension along a longitudinal axis (X), the spindle (10) having a right hand thread (11) and a left hand thread (12), both threads provided over a common longitudinal length of the spindle, the spindle (10) being adapted to be rotated by a driving device (60). The linear actuator further comprises a first nut member (20) provided with a right hand thread (21) and a second nut member (30) provided with a left hand thread (31). The first and the second nut members (20, 30) are in threaded connection with the spindle (10) in such a way that rotation of the spindle provides opposite linear movement of the nut members (20, 30) relative to each other along the longitudinal axis (X). Thereby, a linear actuator is provided with three parts that all move linearly relative to each other during rotation of the spindle.
摘要:
An actuator arrangement comprises a first screw shaft, a first nut cooperating with the first screw shaft such that rotation of the first screw shaft causes the first nut to translate thereon, a second screw shaft, a second nut cooperating with the second screw shaft such that rotation of the second screw shaft causes the second nut to translate thereon, and first and second linkages connecting the first and second nuts, respectively, to an output member, rotation of the first and second screw shafts to cause translation of the first and second nuts towards one another causing extending movement of the output member and rotation of the first and second screw shafts to cause translation of the first and second nuts away from one another causing retracting movement of the output member.
摘要:
A linear actuator having an output shaft having a pair of driven wheels mounted thereon. One of the driven wheels is rotatably mounted in a fixed plane and has a drive nut for an associated thread on the output shaft. The other drive wheel is rotatably fixed to the output shaft. An input shaft is in side-by-side relationship with the output shaft and adapted to be rotated by a suitable power source. The input shaft provides a drive wheel for each of the driven wheels, with the ratio between each drive and driven wheel set being chosen to rotate the driven wheels at different speeds in the same rotational direction and thereby produce a controlled axial movement of the output shaft in a direction depending upon the relative rotation of the driven wheels. The other driven wheel and the drive wheel of its set are in the form of meshing helical gear wheels. A fail-safe arrangement is provided and has a clutch between the drive wheels of the input shaft, a back-drive for the output shaft, and biasing means for effecting a back-drive. The arrangement is such that the meshing helical gears impart an axial force to engage the clutch only while power is supplied, and the biasing means are operative to back-drive the output shaft to a fail-safe position when the power is terminated.
摘要:
A system for retracting the drive spindle of a power tool includes a drive shaft which has a spline portion and a threaded portion. During normal operation, the drive spindle is rotated by interconnection of a drive gear with the splined portion of the drive spindle. When it is desired to retract the drive spindle, a drive spindle feed gear is locked into position and the threaded engagement of the drive spindle feed gear and the drive spindle causes the drive spindle to retract.
摘要:
A linear actuator includes a single drive gear that engages two driven gears of the same pitch diameter, which in turn drive a spindle and a sleeve, respectively. The sleeve is internally threaded to receive the spindle, which is externally threaded. The sleeve and spindle are driven rotationally at slightly different rates due to different numbers of teeth on the two driven gears, producing linear motion of the spindle relative to the sleeve. The drive gear can be rotated in increments corresponding to integral numbers of teeth and the rest positions of the gears can be full engagement positions to minimize play in the gears.
摘要:
A motion-transmitting device utilizing a double differential screw principle is disclosed. One differential screw mechanism including first and second sets of threads of different pitch is operatively coupled to another differential screw mechanism having third and fourth sets of threads of different pitch. By providing the first and second sets of threads with a pitch difference not equal to the difference in pitch between the third and fourth sets of threads, a double differential movement is established.