Abstract:
The present invention discloses a method of constructing a high-frequency vibratory stress relief device for eliminating residual stress of a small work-piece. The method comprises the following steps: fabricating a high-frequency vibration energy amplification device; fabricating a clamping device; mounting the high-frequency vibration energy amplification device; obtaining surface residual stress distribution on the small work-piece by means of X-ray diffraction; establishing a finite element model of the small work-piece; determining a target frequency f, determining the structural dimensions of the high-frequency vibration energy amplification device; analyzing the displacement mode to obtain loci of the vibration node lines and number of the vibration node lines; clamping the small work-piece; attaching strain gauges; connecting all devices. The present invention has the advantage of being able to increase the vibration energy acting on the small work-piece to achieve a better effect of high-frequency vibratory stress relief.
Abstract:
A method of machining a screw is provided that is capable of preventing formation of a protruding section at a thread tip section. A thread is formed by cutting on a cylindrical body, and a surface of the thread is plastically deformed by rolling. Because of the cutting, a width between-side surfaces of a thread tip section is in a narrowed state as compared to a normal width. This width is narrowed toward a tip of the thread while a thread body section has a width expanded as compared to a normal width. Consequently, the side surfaces are formed to bulge by an excess thickness portion as compared to normal side surfaces. The rolling plastically deforms both side surfaces to cause the excess thickness portion to plastically flow toward the side surfaces.
Abstract:
There is provided an R-θ table apparatus which freely movies one table on a plane in the forward-and-rearward and leftward-and-rightward directions and in the rotational direction. The R-θ table apparatus changes a horizontal distance between a center line of a main axis of a driving apparatus and the action point by elevating an elevating base, and a table is moved to an arbitrary position without rotating along a guide member.
Abstract:
A bone plate system for internal fixation of bone fractures includes a bone plate having a plurality of bone plate holes. The holes are constructed to receive either a non-locking, locking, or variable-angle locking bone screw. The holes have discrete columns of teeth or thread segments arranged around the inner surface of the hole for engaging threads on the heads of locking and variable-angle locking bone screws. Conventional locking bone screws engage the bone plate coaxially with the central axis of the bone plate hole. Variable-angle locking bone screws can engage the bone plate at a selectable angle within a range of selectable angles relative to the central axis of the bone plate hole. The head of the variable-angle locking screw is at least partially spherical, and the thread thereon has a profile that follows the arc-shaped radius of curvature of the spherical portion of the screwhead.
Abstract:
The present invention prevents the occurrence of variation in the lead of a threaded section of a machined article (19a) resulting from the effects of thermal expansion of the machined article (19a) during machining. A thermal expansion amount that relates to the axial direction of the machined article (19a) during machining is measured by measurement means (13), history information for the thermal expansion amount that relates to the machined article (19a) during machining is obtained from the result of the aforementioned measurement, and a control unit (17a) determines the relative rotational speed of a rotary drive shaft (11) or the feeding speed of an axial feeding device (16a) with respect to the next machined object (19a) that is to be machined on the basis of the history information for the thermal expansion amount of the machined object (19a) that has been machined.
Abstract:
The present invention is a systematic displacement bone screw having minor and major thread diameters that are constant instead of tapered. The crests at the tip of the screw are narrower than the crests near the screw head resulting in a smaller distance between the thread flanks, which displaces and/or compresses more bone matter. Because the major diameter remains constant, the diameter of the hole made by inserting the screw is consistent over the length of the screw allowing the screw to be adjusted without loosening. The systematic displacement screw with varying crest thicknesses also avoids the need to use a larger diameter screw in place of a removed screw during a repair procedure. Rather than increasing the size of the hole, the systematic displacement screw can be used for the both the original screw and the replacement screw.
Abstract:
A method and apparatus are provided to machine a curved surface such as an inner or outer peripheral surface of a pipe. The pipe is held stationary during machining and a rotatable spindle of a machine head moves along multiple orthogonal axes to align the rotational axis of the spindle with the longitudinal pipe axis. Preferably, the pipe axis is located by using a touch probe to engage the curved surface at multiple spots and the calculating the location of the pipe axis. The cutting tool, which is preferably a cutting tool insert, is rotated by the spindle to machine the curved surface.
Abstract:
A method and apparatus are provided to machine a curved surface such as an inner or outer peripheral surface of a pipe. The pipe is held stationary during machining and a rotatable spindle of a machine head moves along multiple orthogonal axes to align the rotational axis of the spindle with the longitudinal pipe axis. Preferably, the pipe axis is located by using a touch probe to engage the curved surface at multiple spots and the calculating the location of the pipe axis. The cutting tool, which is preferably a cutting tool insert, is rotated by the spindle to machine the curved surface.
Abstract:
A bone plate system for internal fixation of bone fractures includes a bone plate having a plurality of bone plate holes. The holes are constructed to receive either a non-locking, locking, or variable-angle locking bone screw. The holes have discrete columns of teeth or thread segments arranged around the inner surface of the hole for engaging threads on the heads of locking and variable-angle locking bone screws. Conventional locking bone screws engage the bone plate coaxially with the central axis of the bone plate hole. Variable-angle locking bone screws can engage the bone plate at a selectable angle within a range of selectable angles relative to the central axis of the bone plate hole. The head of the variable-angle locking screw is at least partially spherical, and the thread thereon has a profile that follows the arc-shaped radius of curvature of the spherical portion of the screwhead.
Abstract:
A screw device is provided with a screw shaft 5 formed, on an outer peripheral surface thereof, with a ball member rolling groove 6 in form of spiral, a nut 1 formed, on an inner peripheral surface thereof, with at least single one-turn of groove 4 constituted by a loaded ball rolling groove 2 having a partial circle less than one circle of groove and corresponding to the ball rolling groove 6 of the screw shaft and a ball circulation groove 3 connecting one and other ends of the loaded ball rolling grove 2, and a plurality of balls arranged and accommodated between the ball rolling groove 6 of the screw shaft 5 and the loaded ball rolling groove 2 and the ball circulation groove 3 of the nut 1. The loaded ball rolling groove 2 and the ball circulation groove 3 of the nut 1 are formed by cutting the inner peripheral surface of the nut which was preliminarily heat-treated. According to the screw device thus formed, the positional relationship between the loaded ball rolling groove and the ball circulation groove can be precisely set.