Abstract: A lead screw assembly having a lead screw rotatable within a hollow tubular portion of a reinforcing rail. A nut engages with threads of the lead screw and is movable along the reinforcing rail. The lead screw includes plurality of first threaded portions having an outer diameter and extending lengthwise of the lead screw; and at least one second gap portion having an outer diameter that is less than the outer diameter of the first threaded portions. The second gap portion is positioned between adjacent first threaded portions of the lead screw. At least one generally U-shaped bearing is secured within the reinforcing rail and contacts the lead screw at a second gap portion. Each U-shaped bearing supports the lead screw along its length as the screw rotates within the rail, so that the lead screw assembly can be safely operated at high speeds over comparatively long distances while minimizing whipping and vibration of the lead screw.

Abstract: An auxiliary adjusting device for a rolling mill stand includes a adjusting shaft, a cylindrical member forming an adjusting spindle and having a first outer thread cooperating with the inner thread of a support sleeve fixedly connected to the cross-beam, and a central recess provided with longitudinal teeth, a carrier secured to a bottom of the cross-beam, projecting into the central recess of the cylindrical member, and carrying, at its end side, a tooth gear that functions as a planet gear that cooperates, on one hand, with a tooth gear secured at an end of the adjusting shaft which extends through the carrier, and serving as a sun gear, and, on another hand, with the longitudinal teeth of the central recess of the cylindrical member, and an adjusting pressure sleeve connected with the support sleeve for longitudinal displacement relative thereto but without a possibility of rotation relative thereto.

Abstract: In a ball screw drive comprising a spindle (1), a nut (3) surrounding the spindle (1), and balls (4) arranged between the spindle (1) and the nut (3), which balls (4) are in rolling contact with a screw track (2) formed on the spindle (1) and on corresponding screw tracks (7, 12) formed on rings arranged within the nut (3) comprises a deflecting region for returning the balls (4) from a run-out end of a common turn of the screw tracks (2, 7, 12) to a run-in end of this turn, the screw tracks (7, 12) of the rings arranged in the nut (3, 15) are made on front faces of these rings with the screw tracks (7, 12) of two adjacent rings defining together with the screw track (2) of the spindle (1, 18), an endless circulation channel for the balls (4).

Abstract: A fastener assembly for making it easier to tighten and loosen the fastener in confined work spaces.

Abstract: A vibration-dampening base for a ball-type lead screw of a load port transfer system is disclosed. A load port transfer system includes a vertical arm drive motor assembly, a ball-type lead screw, and a vibration-dampening base connecting the vertical arm drive motor assembly to the ball-type lead screw. The vibration-dampening case can include a cross member into which the ball-type lead screw is disposed, one or more pillar members supporting the cross member, and one or more support stands. Each support stand supports a corresponding one of the one or more pillar members.

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: A head lift body (42) with a head assembly (30) mounted thereon has a nut (45) engaged with a lead screw (41). The head lift body has an integral structure formed by resin molding with a through hole, a hollow opening, and a guide portion (47). The through hole receives the lead screw inserted therethrough. The hollow opening is formed at the center of the head lift body to accommodate a backlash preventing mechanism (43). The guide portion inhibits the rotation of the head lift body and guides the head lift body moving up and down along a rotation center axis of the lead screw. The backlash preventing mechanism comprises a preload bushing (431) and a preload spring (432). The preload bushing has an internal thread to be engaged with the external thread of the lead screw. The preload spring presses the head lift body against the preload bushing along the rotation center axis of the lead screw.

Abstract: A leadscrew assembly has a wire-wound leadscrew driven by a mechanical drive. A preloaded leadscrew wire nut assembly serving as a leadscrew follower includes a first wire nut having at least one turn of a first-nut wire overlying and engaged to the groove between the turns of the thread wire, and a second wire nut having at least one turn of a second-nut wire overlying and engaged to the groove between the turns of the thread wire. The second wire nut is spaced apart from the first wire nut along a leadscrew axis. The leadscrew wire nut assembly further includes a compressed preload spring maintaining a compression preload against the second wire nut, and a wire-nut-assembly housing overlying the first wire nut, the second wire nut, and the preload spring. The wire-nut-assembly housing maintains the preload spring in compression.

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: A fin actuator for a portable missile and a method of using the same. One aspect of the present invention includes a fin or wing actuator that meets very strict criteria to fit within a compact, portable missile while substantially limiting backlash. Another aspect of the present invention is a method of fin actuation in a portable missile while substantially limiting backlash.

Abstract: A linear stage having a screw-nut assembly is actuated by the rotational motion of the screw. A mechanism, which is an integral part of the nut, quickly disconnects the screw and the nut, allowing rapid positioning of the linear stage in both the forward and reverse direction. The motion of said stage has a resolution given by the thread pitch of the screw and the nut; and a travel only limited by the length of the screw. The quick disconnect screw-nut assembly mechanism described in this invention is achieved by axial preloading said nut and allowing said nut to pivot perpendicular to the axis of said screw. Two or more linear stages having said screw-nut assembly are concatenated with one another to form a multi-axis positioning device.

Abstract: The present invention relates to a feed screw driving apparatus that moves a power transmission member, which engages a feed screw, in an axial direction of the feed screw by rotationally driving the feed screw using a driving source, such as an electric motor, and also to an information recording and/or reproducing apparatus that moves a pick-up apparatus with this feed screw driving apparatus and records and/or reproduces an information signal onto or from a disc-like recording medium

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 actuator comprises a rotatable input member and a non-rotatable primary output member, wherein the input member is provided with a screw thread formation within which a plurality of spherical members are received to provide a ball screw coupling between the input member and the primary output member. The actuator includes a secondary output arrangement having first and second screw threaded parts in screw treaded engagement with the input member to provide a screw thread coupling between the input member and the secondary output arrangement. The first and second screw threaded parts are axially movable relative to one another, whereby, in the event that the ball screw coupling fails, relative axial movement of the first and second screw threaded parts serves to lock the first and second screw threaded parts onto the input member, thereby to stall the actuator.

Abstract: An anti-backlash transmission mechanism that eliminates backlashes is disclosed. An actuator is connected to a transmitted element and a driven gear. The driven gear matches with a driving gear to be receive power transmitted from the driving gear. Through the actuator, the driving gear and the driven gear match tightly in the normal state to eliminate the backlash during positioning. During transmission, the pressure between the driving gear and the driven gear decreases, lowering the friction in between.

Abstract: Disclosed is an anti-backlash screw and nut assembly adapted for converting rotational motion into linear motion. The assembly comprises a screw rotated by a motor; first and second nut blocks threadedly coupled with the screw to be linearly moved, the second nut block being formed on an upper surface thereof with an insertion pin; a pair of springs for connecting and applying compression or tensile force to the first and second nut blocks in a manner such that flanks of threads of the screw and the nut blocks can be brought into contact with each other while not causing backlash; and a plate member secured to an upper surface of the first nut block by fastening bolts and defined with a slot in which the insertion pin of the second nut block is inserted to be moved therealong.

Abstract: A casing of a ball bearing which holds a ball screw can be displaced on a supporting stand against urging force of a compression coil spring and a tensile coil spring. If vibration of the ball screw is transmitted to the casing, the casing attempts to move on the supporting stand. However, when, due to the vibration, the casing is displaced against the urging force of the compression coil spring and the tensile coil spring, the urging force forcibly attempts to return the casing to its original position. A frequency of vibration of the casing is thereby forcibly changed.

Abstract: A drive device for a moveable part, in particular a hinged side window of a vehicle, with an actuating drive and with a threaded piece which is driven by the actuating drive and which meshes with an associated threaded piece, the associated threaded piece moving the part, there being provision, in order to reduce undesirable noises, for individual flights of at least one threaded piece (14) to be designed in such a way that they come to bear under the effective force in the respectively associated flights of the other threaded piece.

Abstract: A power steering apparatus comprises a rotary cylinder supported with its movement in the axial direction restrained and rotated coaxially with the steering shaft by the force a transmitted from the motor for assisting steering, a plurality of feed rings held eccentrically in said rotary cylinder with their axial centers in parallel, and an engaging groove formed spirally around the outer circumference of the steering shaft for engaging with the projections provided circumferentially on the inner surfaces of the respective feed rings. With this arrangement, it becomes possible to convert the rotation of the motor into the movement in the axial direction of the steering shaft. Thus, this power steering apparatus has a low noise power transmission mechanism with a simple structure.

Abstract: A ball nut drive assembly includes a ball nut having a bore extending axially therethrough, a ball screw extending through the bore of the ball nut and being cooperatively engaged with the ball nut, and a spring compliant member received on the ball screw and positioned adjacent the ball nut. The spring compliant member is tensioned to bias the ball nut in the axial direction along the ball screw. The ball nut is positioned within a housing, which is preferably fabricated of aluminum, and is generally rotatably supported therein by first and second sets of ball bearings. The spring compliant member is in intimate contact with a first inner surface of the housing and biases the ball nut against a second inner surface of the housing. Races encapsulating the first and second sets of bearings may be positioned adjacent the ball nut and in intimate contact with the first and second inner surfaces of the housing.

Abstract: An anti-backlash nut assembly is on a reinforced lead screw having a threaded lead screw rotatable about a central axis. A hollow, elongated reinforcing rail extends lengthwise of and surrounding the lead screw. The reinforcing rail has a slot extending lengthwise of the central axis. The anti-backlash nut assembly has a nut moveable along the reinforcing rail. The anti-backlash nut has a pair of separate nut portions. Each nut portion has a tongue extending radially through the slot and having threads engagable with the threads of the lead screw for moving both nut portions in reciprocating motion lengthwise of the rail when the screw is rotated. A spacing mechanism forces the nut portions apart to urge the flanges of their threads into forcible engagement with the threads of the lead screw to prevent backlash while the anti-backlash nut translates laterally along the reinforcing rail.

Abstract: An anti-backlash nut is assembled on a reinforced lead screw for bilateral motion lengthwise of the lead screw as the screw is rotated. A hollow, elongate reinforcing rail extends lengthwise of and surrounds the lead screw. A slot in the rail extends lengthwise of the central axis of the lead screw. The anti-backlash nut comprises two separate portions, each portion having a tongue which extends radially through the slot and has threads engageable with the threads of the lead screw for moving both nut portions in reciprocating motion lengthwise of the rail when the screw is rotated. Spring means are employed for forcing the nut portions apart to urge the flanges of their threads into forcible engagement with the threads of the lead screw to prevent backlash, while the anti-backlash nut translates laterally along the reinforcing rail.

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: 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: A device for slip-fittably connecting together a ball nut and a moving member moved by the ball nut includes a first connecting member fixedly attached to the ball nut. The first connecting member has first registration elements disposed radially opposite relative to the ball nut. A second connecting member is fixedly attached to the moving member. The second connecting member has cooperative second registration elements disposed radially opposite relative to the ball nut which cooperate with the first radially opposite registration elements. The first and second registration elements are slip-fittably connectable together and provide indexed registration within predetermined tolerances in the axial, radial and circumferential directions relative to the ball nut.

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 rolling-body screw drive (10a) comprises a threaded spindle (12a) with a spindle axis (S), and a double nut (14a) which runs on the threaded spindle (12a) and has two separately formed individual nuts (16a, 18a) which are connected essentially rigidly to one another in the direction of the spindle axis (S). In this case, for setting a desired level of play or a desired prestressing in relation to the threaded spindle (12a), the two individual nuts (16a, 18a) can be rotated continuously relative to one another about the spindle axis (S) and can be secured in any desired rotary position relative to one another corresponding to the desired level of play or the desired prestressing.

Abstract: A self-lubricating ballscrew has a screwshaft and a ballnut surrounding the screwshaft and provided with a re-circulating path for a plurality of balls which roll between the ballnut and the screwshaft when the ballscrew is in use. Lubrication means are in contact with the helical groove of the screwshaft to provide lubrication therefor. The self-lubricating means comprises a lubricant impregnated solid having an elongate portion which follows the path of and is received in the helical groove of the screwshaft. The cross-section of that portion is different from that of the said groove, so that the contact region between the said portion and the said groove coincides with the lines of contact between the balls and the screwshaft. The deposit of lubricant is thereby concentrated on those lines.

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.