Abstract: In a linear drive device, a movable member is driven using a guide shaft and a lead screw supported by a bracket. Since a nut mechanism, which with the lead screw configures a feed screw mechanism, is provided with a first spring between two nuts, it is possible to limit rattling of the nuts with respect to the lead screw. Of the two nuts, the first nut provided on the side opposite a motor and a first plate is not able to move relative to the movable member in the axis direction. As a result, when a member to be driven is loaded on the movable member and the movable member is driven in the direction approaching the first plate, the first plate and members disposed therearound are not susceptible to interference by the member being driven.

Abstract: A threaded nut for a ball screw drive is provided. The threaded nut includes a cylindrical central piece ending at a flange. A deflecting body is attached to the cylindrical central piece and is configured to recirculate balls during operation of the threaded nut. A pin fixes the deflecting body to the flange. In embodiments, the flange and the deflecting body each have recesses that are aligned with one another, and the pin extends through those recesses.

Abstract: According to the embodiments, it is possible to mitigate noise by compensating for the clearance inside the bearing supporting the rotation of the ball nut and the clearance between the ball nut and the ball screw and prevent excessive friction between the ball nut and the ball screw and inside the bearing to thereby allow the driver a better steering feel.

Abstract: A linear actuation screw having a first end portion, a second end portion on an opposite side as the first end portion, and a sloping intermediate portion between the first end portion and second end portion. The first end portion has a threaded outer wall having a generally constant first diameter over at least a portion of its length and is configured to advance a nut or a sliding member along at least a portion of the first end portion. The second end portion has a threaded outer wall having a generally constant second diameter that is different from the first diameter and is configured to receive a motor fastening nut around it in order to secure the linear actuation screw to a motor. The sloping intermediate portion includes an outer wall that is generally smooth and continuous over at least a majority of the area of the outer wall.

Abstract: A motion conversion mechanism includes a shaft having an external thread and a cylinder having an internal thread that is screwed with the external thread. The motion conversion mechanism converts rotating motion of one of the shaft and the cylinder into linear motion of the other of the shaft and the cylinder. The cylinder is provided with two internal thread portions, each having the internal thread, such that a threadless portion is interposed between the two internal thread portions in an axial direction.

Abstract: A linear motion system comprises a guiding member, a moving member, a plurality of rolling members and a preload adjusting module. The moving member is slidably disposed on the guiding member. The moving member and the guiding member together form a circulation path. When the guiding member moves with relative to the moving member, the moving member can generate a linear movement with relative to the guiding member. The rolling members are accommodated in the circulation path. The preload adjusting module is disposed on the moving member, and comprises a preload assembly and a preload regulator. The preload regulator applies a thrust to the preload assembly to adjust a preload value generated by the rolling members and applied to the moving member.

Abstract: Actuator having a spindle drive (1) for a rear wheel steering system, including a spindle (2) with a spindle thread (2a) and a spindle nut (3) with a nut thread (3a). The spindle thread (2a) and the nut thread (3a) are designed as displacement threads and the spindle nut (3) threadedly engages with the axially displaceable spindle (2) by way of the displacement thread. The spindle thread (2a) and the nut thread (3a) are braced against one another, in the longitudinal direction of the spindle (2), by a bracing element (4). The bracing element (4) is in the form of a threaded ring having an internal thread (4a) which engages with the spindle thread (2a). The threaded ring (4) is supported relative to the spindle nut (3) by at least one spring element (5, 6), and the at least one spring element (5, 6) is made of an elastomer.

Abstract: An actuator includes at least one threaded spindle, at least one switch, at least one actuating element configured to actuate the switch, and at least one housing relative to which the threaded spindle is movable. The actuating element is attached to the housing. The housing may include at least one wall extending circumferentially around the threaded spindle and a first axial end wall and a second axial end wall, and the threaded spindle may pass through the first and second axial end walls. The first axial end wall may overlie the at least one switch, and a first end of the at least one actuating element may be connected to the housing and a second end of the at least one actuating element may extend between the at least one switch and the first axial end wall.

Abstract: A pushing unit is stopped just before abutting against a rear end of a syringe to reliably prevent unwanted extrusion of a chemical liquid from a syringe. An injecting apparatus for injecting a chemical liquid includes: an injection head to which a syringe filled with the chemical liquid is to be mounted; a pushing unit provided on the injection head and pushing a rear end of the syringe; a rear end detection unit provided on the injection head and detecting the rear end in a contactless manner; and a control unit configured to control the injection head, the control unit acquiring a forward movement distance that the pushing unit is to be moved forward after the rear end is detected, and causing the pushing unit to move forward by the forward movement distance after the rear end is detected and to stop at a position separated from the rear end.

Abstract: An adjustment mechanism the includes a screw, a support having first and second transverse walls perpendicular to the screw, a casing having first and second end faces arranged facing the first and second transverse walls and having a nut housing which opens in opposite first and second openings, a first elastomer pad interposed between the first transverse wall of the support and the first end face of the casing, a second elastomer pad interposed between the second transverse wall of the support and the second end face of the casing, a nut screwed onto the screw, a bearing engaged in the second opening of the casing and traversed by the screw. The nut is in rigid abutment against the casing in the direction of the first opening and the bearing is in elastic abutment against the second elastomer pad.

Abstract: A ball screw with tilt detector includes a screw rod, two screw nuts, a channel, a plurality of balls, and a tilt detector. The screw rod is extended along a direction of an axis. The two screw nuts are installed on the screw rod and capable of moving along the axis. The tilt detector is disposed between the two screw nuts to detect a tilt angle and a preload of the two screw nuts. The tilt detector includes a force receiving element, at least one first strain sensor, and at least one second strain sensor. The force receiving element includes a point symmetric ring-type structure, and the ring-type structure has two planes which are parallel to each other and respectively contact the two screw nuts.

Abstract: An anti-backlash device for preventing backlash derived from a moving load on a screw used in converting rotary motion into linear motion, the anti-backlash device comprising: a cylindrical pressure actuator integrally formed with a helical thread and axially mounted on the screw; a cradle integrally formed with a helical thread and internal cradle threads, the cradle being mounted exterior to and in mechanical contact with both the cylindrical pressure actuator and the screw, and a preloading means comprising a wave spring and a retainer mounted in the cradle.

Abstract: A nut driven by a lead screw and stepper motor has an internal concave recess for holding high viscosity grease that is semi-solid at ambient temperature and spaced from the lead screw. Grease flow ensues with lead screw motion causing a slow flow of grease coating the lead screw with a thin coating of grease as the nut travels back and forth over the lead screw. The nut may be an anti-backlash nut or a single member nut with both having a concave recess about the lead screw for the grease.

Abstract: A double nut ball screw capable of sensing preload includes a screw rod, two nuts, a connection key, multiple balls, a deformable annular platform having a U-shaped cross section with a bottom wall portion and two sidewall portions integrally connected with two opposite lateral sides of the bottom wall portion, and an annular force sensor mounted on the bottom wall portion of the deformable annular platform and located between the two sidewall portions. The deformable annular platform has a protruded portion located at the outer surface of the bottom wall portion opposite to the force sensor, and is disposed in the gap between the two nuts and wedged between two mating surfaces of the two nuts with the distal ends of the sidewall portions abutted against the mating surface of one nut and the protruded portion abutted against the mating surface of the other nut.

Abstract: A backlash-free spindle nut is disclosed with a thread that can be meshed with a spindle. The spindle nut has a first nut part with a first internal thread and a second nut part with a second internal thread that can be twisted in relation to the first nut part. To generate a preload between the first nut part and the second nut part, the spindle nut has an elastic element. The preload can be adjusted through relative twisting between the first nut part and the second nut part. The elastic element can work between the first nut part and a secure intermediate part, whereby relative twisting between the first nut part and the second nut part can be locked by locking a relative twisting position between the second nut part and the intermediate part.

Abstract: A manual drilling apparatus equipped with a device for control of advance, which includes a fixed part and a mobile part with movement of translation relative to the fixed part during the drilling, as well as a system for control of the movement of translation of the mobile part relative to the fixed part, wherein the fixed part and the mobile part comprise respectively at least one fixed tube and at least one mobile tube which slide relative to one another, the fixed and mobile tubes being coaxial to the axis of rotation of the tool supported by the apparatus.

Abstract: A system and method for retrofitting a manual benchtop milling machine utilizing servo controls and/or stepper motors, in which a retrofit kit and method for the modification of a milling machine incorporates ball screws and ball nuts, without removing or replacing the original acme nuts, which have been properly configured and aligned to the machine on which they were originally installed. The retrofit kit and method allow for the modification using the alignment of the original acme nuts in their proper location and alignment obviating the need for custom machining or alignment.

Abstract: A nut and lead screw assembly is disclosed. The nut includes a plurality of flexible fingers for adjusting the engagement of a threaded or unthreaded portion of the nut with corresponding threads of a lead screw. The engagement between the nut and the lead screw is adjusted by installing at least one radial compression member into a circumferential groove formed in the outer surface of the flexible fingers.

Abstract: A ball screw includes a screw rod having an external thread; two screw nuts having an internal thread and a circulatory passage each, a spiral path being formed between the internal threads and the external thread and communicating with the circulatory passage, each of the two screw nuts having a keyway located on respective toric surfaces of opposite ends of the two screw nuts, the two keyways facing each other; a link mounted inside the two keyways to traverse the two screw nuts; a force sensor mounted between and squeezed by opposite sides of the two screw nuts; and a plurality of balls located inside the spiral path or the circulatory passage and keeping rolling while moving.

Abstract: A no-lash nut assembly for installation on a threaded rod and including a lead nut, a trailing nut, a transition nut and a torsion spring. The lead and trailing nuts have threaded bores for mating with the rod. The trailing nut has an external surface configured for engagement with the lead nut to prohibit relative rotation and allow relative axial movement. The transition nut has a threaded bore for mating to trailing nut, an external surface defining a slot, and a front face having a mating surface corresponding to the rear face of the lead nut to allow relative axial movement between the lead nut and the transition nut. The torsion spring has a pin and a hook. The pin protrudes into the rear face of the lead nut and the hook protrudes into the transition nut slot to apply a rotational force on the transition nut.

Abstract: Ball screw nut includes first and second ball bearing accommodating inserts that can be part of a ball bearing return system in the nut with the first and/or second inserts having a body with a passage for ball bearings, which opens in a first direction; and a depending foot having a heel and toe, which joins the body and which has below the body in the toe of the foot for the ball bearings a channel that faces in a second direction substantially perpendicular to the first direction and that can communicate ball bearings with the passage in the body to or from a spiral raceway of the nut and an associated ball screw shaft.

Abstract: The claimed subject matter provides an anti-backlash nut for use with a leadscrew. The nut can include two or more threaded sections and at least one semi-flexible section. The anti-backlash nut can be of one-piece construction and utilize the one or more flexible or biasing sections to apply one or more forces or offsets to the threaded sections to mitigate backlash.

Abstract: A no-lash nut assembly for installation on a threaded rod and including a lead nut, a trailing nut, a transition nut and a torsion spring. The lead and trailing nuts have threaded bores for mating with the rod. The trailing nut has an external surface configured for engagement with the lead nut to prohibit relative rotation and allow relative axial movement. The transition nut has a threaded bore for mating to trailing nut, an external surface defining a slot, and a front face having a mating surface corresponding to the rear face of the lead nut to allow relative axial movement between the lead nut and the transition nut. The torsion spring has a pin and a hook. The pin protrudes into the rear face of the lead nut and the hook protrudes into the transition nut slot to apply a rotational force on the transition nut.

Abstract: A lead screw nut support arrangement includes a wall having a width and a through hole that passes through the wall. A support bushing passes through the through hole in the axial direction, leaving an amount of play, and having a length greater than the thickness of the wall. The support bushing is supported in the through hole movably in the axial direction. A lead screw nut is also included whose end face adjoins a first end face of the support bushing on the inner side of the wall. The support arrangement also includes a mount that braces a second end face of the support bushing against the lead screw nut such that the lead screw nut is elastically loaded in the direction away from the wall.

Abstract: Revolving rollers, each provided on an outer peripheral surface thereof with revolving roller grooves extending therearound, are caused to mesh with a rack rod thread of a central rack rod with an axial angle over a lead angle of the rack rod thread and arranged for rotation on a holder member to be twisted. The holder member is rotated round the rack rod by a motor to translate the rack rod. A large thrust can be generated while ensuring a high reliability since a high efficiency is achieved by realizing rolling contact in set points of mesh of the rack rod thread and the revolving roller grooves, points of mesh are made planar, and interference in other points than the points of mesh can be suppressed. Also, play can be restricted by assembling the revolving rollers to the rack rod thread while applying torque in a direction, in which the axial angle is increased.

Abstract: An actuator for a motor vehicle with an electric motor having an output shaft, a gearbox that is connected to the output shaft that includes a spindle nut, and a spindle that engages the spindle nut. The spindle nut comprises one main portion and at least one axial socket. The axial socket: (a) is solidly connected to the main portion, more specifically is integral with the main portion, (b) comprises an internal thread cooperating with the spindle and (c) is configured to be radially elastic. An elastic element is provided which fits against the axial socket and pushes the internal thread thereof into engagement with the spindle.

Abstract: An actuator in one embodiment includes a threaded shaft; a shaft engaging portion coupled to the threaded shaft, the shaft engaging portion being moveable in a direction parallel to an axis of the threaded shaft upon a relative rotation between the threaded shaft and the shaft engaging portion; and a ceramic bushing coupled to the shaft engaging portion, the bushing encircling the threaded shaft.

Abstract: A motorized anti-backlash linear actuator comprises a motor; a hollow shaft that is rotated about a central axis by the motor, an anti-backlash nut that is nested at least partially inside the hollow shaft; and an externally threaded rod or lead screw that engages with the anti-backlash nut such that the rotation of the hollow shaft and the nut imparts a linear motion to the rod that is substantially free of backlash. Nesting the anti-backlash nut at least partially within the hollow shaft provides greater stability to the actuator, and permits high speed operation.

Abstract: A drive mechanism include a movable element which has at least one bearing arm; a linear guide shaft for linearly guiding the movable element without rotating; a driving device driving the movable element linearly along the linear guide shaft; a driven member driven, by the driving device, in a direction parallel to the linear guide shaft; a first guide hole formed on the bearing arm; a second guide hole formed on the driven member, the first and second guide holes being identical in size and in cross sectional shape; a tubular bearing member fitted into the first and second guide holes, the linear guide shaft being fitted completely through the tubular bearing member to be freely slidable therein; and a retaining device formed on the tubular bearing member and the driven member to prevent the tubular bearing member from moving relative to the driven member.

Abstract: A track system (18) of the type used to adjust the position a supported element such as vehicular seat (12) includes a pair of base rails (20) that slidably interact with a respective pair of driven rails (22). A transverse rail (24) is attached to each of the driven rails (22) so that the driven rails (22) slide together as a unit. A motor (34) is supported on the transverse rail (24) and includes a pair of drive shafts (36) emanating from either end. The drive shafts (36) carry on their distal ends' respective worm gears (38) which are contained within a transmission assembly (26). The worm gears (38) mesh with external teeth on respective drive nuts (54) which interact with a lead screw (28) that can be oriented to either remain stationary relative to the base rails (20) or can be rotatably fixed within the driven rails (22). The drive nut (54) is prevented from causing objectionable noise and premature wear in operation by the inclusion of one or two compressible washers (66).

Abstract: The present invention consists of a connection, having an anchored, elongated tension member, a fastening member attached to the elongated tension member, a resisting member that receives the elongated tension member and an expansion device that receives the elongated tension member there through. The expansion device is formed with a sleeve. First and second bearing members are received in the central aperture of the surrounding sleeve A torsion spring connects the first and second bearing members and is located within the surrounding sleeve. The torsion spring biases the first and second members in opposite rotational directions.

Abstract: An actuator including a threaded shaft and a carriage having a shaft engaging portion coupled to the threaded shaft. The carriage is moveable in a direction parallel to an axis of the threaded shaft upon a relative rotation between the threaded shaft and the shaft engaging portion. A ceramic bushing is coupled to the shaft engaging portion of the carriage, the bushing surrounding the threaded shaft. The ceramic bushing is much harder than heretofore used materials and results in greatly reduced particulate formation. The carriage or portion thereof can be formed around the bushing, e.g., by injection molding.

Abstract: Apparatus for screw transmission on a spindle comprising a nut having at least a first and second part with internal threads, at least one bore in the first and second parts, and at least one spring located within the at least one bore of the first and second parts and arranged with a bending load acting crosswise to a longitudinal direction of the bore. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Abstract: A leadscrew mechanical drive includes a leadscrew having a leadscrew axis and a leadscrew thread with a nonzero leadscrew thread pitch. A leadscrew follower structure preferably having two leadscrew followers is engaged to the leadscrew. Each leadscrew follower includes a threaded insert having an insert thread with a nonzero insert thread pitch different front the leadscrew thread pitch. The insert thread is engaged to the leadscrew thread over a circumferential distance of less than one-half turn of the insert thread. Each leadscrew follower further includes a bearing in which the threaded insert is received and which permits the threaded insert to rotate about an insert axis that is inclined to the leadscrew axis by an angle ? for the first leadscrew follower and ?? for the second leadscrew follower, and a bearing support in which the bearing is received. A preload structure biases each of the leadscrew followers against the leadscrew.

Abstract: There is provided an anti-backlash nut mechanism wherein two segmental nuts composing a nut are not separated when the nuts are disengaged from a male screw. An anti-backlash nut has a main nut and a trailing nut which can be engaged with a common male screw, a coil spring for biasing the main and trailing nuts away from each other, a cylindrical portion formed in conjunction with the main nut so as to surround the lead screw, an insert portion formed in conjunction with the trailing nut to be inserted into the cylindrical portion, pins projecting in the radial direction from either one of the cylindrical portion and the insert portion, and grooves formed around the other one of the cylindrical portion and the insert portion so as to receive the pins from the edge of the cylindrical portion and to engage with the pins in the turning direction of the nuts.

Abstract: The refinement of such harmonic drives according to German Patent 1 98 33 290 C1=European Patent Application 0 974 773 A concerns damping of the noise generation as a consequence of the revolving displacement of discrete tappets (instead of the rotating deformation of the closed hub of a spoked wheel) on the non-round wave generator. Since the feet of the individual—not guided in a cage, but rather connected to one another by a flexible ring band—tappets are no longer solid, but rather split, they are to be able to elastically bend so they may press continuously against the drive core of the wave generator.

Abstract: An assembly including a base and first and second spaced-apart shafts secured to the base and extending generally perpendicular to an elongated aperture of the base. A carrier includes a first support member slidingly receiving the first shaft, a second support member receiving the second shaft, and an elongated opening extending between the support members and generally perpendicular to the shafts. The elongated opening of the carrier is for aligning with the aperture of the base and an elongated slit of a collimator supported on the carrier for passage of an x-ray beam therethrough. A backlash-resistant nut assembly is threadingly received on a threaded portion of the second shaft and secured to the second support member.

Abstract: A carriage adapted for carrying a laboratory instrument such as a pipette, electrode, or syringe is driven by a drive shaft in the form of a lead screw. The lead screw is selectively driven by a high speed drive wheel or by a low speed drive wheel. The drive wheels are coaxially mounted around the drive shaft and concentrically and coaxially arranged with respect to one another. The drive shaft and the two drive wheels all rotate in unison in the same rotary direction.

Abstract: Apparatus embodying the invention includes first and second motors coupled to a carriage assembly for moving the carriage assembly back and forth between first and second end points. The first motor is for developing a force to drive the carriage in one direction and the second motor is for developing a force to drive the carriage in an opposite, second direction. When the first motor causes the movement of the carriage in one direction, the slowing, stopping and reversal of the carriage is achieved by varying the power supplied to the second motor relative to the power supplied to the first motor until the force exerted by the second motor first equals and then exceeds the force exerted by the second motor. So operated, the carriage motion is well controlled and exhibits little, if any, backlash.

Abstract: A screw drive with rolling elements, optionally a ball screw drive, includes a screw spindle with a spindle axis and a double nut running on the screw spindle, with two separately formed single nuts which are substantially rigidly joined in the direction of the axis of the spindle. In order to set a desired play or bias relative to the screw spindle, the two single nuts can be turned continuously about the axis of the spindle relative to each other and fixed in any relative rotary position corresponding to the desired play or bias. According to the invention, a first of the two single nuts or an intermediate element joined thereto and arranged between the two single nuts has at least one peripheral section pressed into an associated aperture in one of the single nuts. In one embodiment, the intermediate element is an annular disk that is arranged orthogonally to the spindle axis.

Abstract: A screw drive (10a) with rolling elements, optionally a ball screw drive, includes a screw spindle with a spindle axis (S) and a double nut (14a) running on the screw spindle, with two separately formed single nuts (16a , 18a) which are substantially rigidly joined in the direction of the axis (S) of the spindle. In order to set a desired play or bias relative to the screw spindle, the two single nuts (16a, 18a) can be turned continuously about the axis (S) of the spindle relative to each other and fixed in any relative rotary position corresponding to the desired play or bias. According to the invention, a first of the two single nuts or an intermediate element (28a) joined thereto and arranged between the two single nuts, as a first alternative, is welded to one of the two single nuts or to at least one part (42a) joined thereto or, as a second alternative, has at least one peripheral section pressed into an associated aperture in one of the single nuts.

Abstract: Screw mechanism having a spindle (1) which is secured in the axial direction and has a spindle axis (1′), and a spindle nut (5) which is connected to a slide (7) which can be driven and is guided in the axial direction, a joint being provided between the spindle nut (5) and the slide (7) in order to compensate for relative transverse movements and tilting between the spindle nut (5) and slide (7), said joint being formed symmetrically to the spindle axis (1′) and having two joint axes which are perpendicular to each other, intersect on the spindle axis (1′) and are assigned at one end to the transverse movement of a bearing plate (6), which is connected to the spindle nut (5), and at the other end to the transverse movement of a bearing plate (8), which is connected to the slide (7), and said joint containing an intermediate plate (9) via which the bearing plates (6, 8) are connected pivotably to each other in order to compensate for any tilting of their joint axes.

Abstract: An anti-backlash nut includes a body having an axially-extending bore and internal threads for engaging a lead screw inserted into the bore. The internal threads are divided circumferentially into three inner segments each movable in a radial direction. The anti-backlash nut also includes springs for independently biasing the inner segments radially inward to contact the lead screw. The anti-backlash nut provides wear compensation as well as anti-backlash to improve positioning repeatability when used with an open loop positioner.

Abstract: A drive assembly for a collimator of an X-ray imaging device includes a carrier which is adapted for translation in the z-direction along two parallel shafts. One of the shafts is coupled to a driver, such as a motor, by a backlash-resistant nut assembly.

Abstract: An anti-backlash device for a positioning stage arranged for the precise movement of components composed of a pair of plates having rail receiving grooves, a pair of rails joining the plates and attached thereto and a work piece mounting table, the anti-backlash device, having a plurality of circumferentially spaced elongate spring members for biasing an interrupted thread into zero clearance engagement with a threaded rod rotatable to move the table along the rails.

Abstract: An anti-backlash nut has flexure members which are continuously biased inwardly against a lead screw by a force-applying sleeve which acts on ramps on the flexure member. The spline means include means on the longitudinal flexure members and the force applying sleeve to impart rigidity to the longitudinal flexure members in a direction tangential to the longitudinal direction of movement of the nut.

Abstract: A ball screw and nut linear actuator has a screw and nut with helical grooves and threads providing a helical raceway between them. The raceway has a ball return portion and provides a track for a train of recirculating load bearing balls. A wiper member carried by the nut has a helical wiper thread which is preloaded to engage an outer side of the helical groove of the screw outboard of the nut. The helical wiper thread has a radially open helical groove for maintaining and distributing a helical ribbon of lubricant on the side of the screw groove upon which it is pressed.

Abstract: An apparatus for converting a rotational movement into a back and forth movement is described, which has a spindle with an outer surface having at least one guiding groove, a bearing body with a wall section surrounding the surface concentrically and a force transfer device with at least one ball mechanism comprising at least one driving ball. The spindle and the bearing body are disposed so that they can be rotated and shifted axially relative to one another. The ball mechanism is mounted in a bearing bore in the wall section and protrudes into the guiding groove as well as towards the outside over the outer extent of the wall section. Moreover, at least one ball race, pretensioning the ball mechanism in the direction of the guiding groove, is slipped onto the bearing body.

Abstract: An anti-backlash nut assembly for translational movement along the axis of a leadscrew in response to rotational movement of the nut assembly relative to the leadscrew. The nut assembly comprises (i) a primary nut having an internal thread which mates with an external thread on the leadscrew; (ii) a secondary nut having an internal thread which mates with the external thread on the leadscrew, the secondary nut being capable of rotational movement about the leadscrew independent of the primary nut; (iii) a spring disposed intermediate the primary nut and the secondary nut; and (iv) a housing connected to the said primary nut which surrounds the spring and the secondary nut, for imparting rotational movement applied thereto simultaneously to the primary nut and the secondary nut.

Abstract: An anti-backlash nut, movable along a rotatable screw. The nut has internal threads complementary to the threads in the screw. The nut has two nut halves movable as a unit and also rotatable relative to each other on the screw, and are connected to the nut halves to induce their relative rotation on the screw in opposite directions. There is an elastomeric friction mechanism, such as a washer, between the two halves to limit their relative rotational movement. The elastomeric friction mechanism is enclosed between the nut halves to have uniform compression.