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.

The invention relates to methods of stabilizing bone implants, including inserting a self-tapping implant having at least two helical grooves running in opposite directions around the implant.

The invention relates to methods of stabilizing bone implants, including inserting a self-tapping implant having at least two helical grooves running in opposite directions around the implant.

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: (1) fabricating a high-frequency vibration energy amplification device; (2) fabricating a clamping device; (3) mounting the high-frequency vibration energy amplification device; (4) obtaining surface residual stress distribution on the small work-piece by means of X-ray diffraction; (5) establishing a finite element model of the small work-piece, obtaining natural frequencies, displacement modes and strain modes of the bending vibration of various orders by means of numerical modal analysis; (6) determining the required strain mode shape and corresponding natural frequency, and record it as a target frequency f; (7) determining the structural dimensions of the high-frequency vibration energy amplification device; (8) analyzing the displacement mode to obtain loci of the vibration node lines and number of the vibration node lines; (9) clamping the small work-piece; (10) attaching strain gauges; (11) connecting the strain gauges with a dynamic strain meter, connecting the dynamic strain meter with a host computer system, connecting the host computer system with a signal generator, connecting the signal generator with a power driver, and connecting the power driver with the electromagnetic exciter. 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.

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: (1) fabricating a high-frequency vibration energy amplification device; (2) fabricating a clamping device; (3) mounting the high-frequency vibration energy amplification device; (4) obtaining surface residual stress distribution on the small work-piece by means of X-ray diffraction; (5) establishing a finite element model of the small work-piece, obtaining natural frequencies, displacement modes and strain modes of the bending vibration of various orders by means of numerical modal analysis; (6) determining the required strain mode shape and corresponding natural frequency, and record it as a target frequency f; (7) determining the structural dimensions of the high-frequency vibration energy amplification device; (8) analyzing the displacement mode to obtain loci of the vibration node lines and number of the vibration node lines; (9) clamping the small work-piece; (10) attaching strain gauges; (11) connecting the strain gauges with a dynamic strain meter, connecting the dynamic strain meter with a host computer system, connecting the host computer system with a signal generator, connecting the signal generator with a power driver, and connecting the power driver with the electromagnetic exciter. 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.

A turning thread automatic diagnosing method includes collecting a spindle actual speed and a feeding shaft actual speed of a lathe; based upon the spindle actual speed and the feeding shaft actual speed, continuously calculating thread errors to obtain a thread error curve; and analyzing an error cause according to the thread error curve. In addition, a turning thread automatic diagnosing system is disclosed, using the method. A data processing system and a storage medium are also disclosed. The technology of the embodiments can automatically identify the problem causing a thread error and provide a corresponding solution.

A method of converting a tubular having NC46 connections to CET43 connections. A method of applying a CET43 thread to a pin connection or a box connection or both. A box connection and a pin connection of the tubular are machined and a CET43 thread applied to the box connection and the pin connection.

A method of converting a tubular having NC46 connections to CET43 connections. A method of applying a CET43 thread to a pin connection or a box connection or both. A box connection and a pin connection of the tubular are machined and a CET43 thread applied to the box connection and the pin connection.

The present invention provides a looseness-prevention screw thread structure including a screw thread having a predetermined pitch, a no-load flank which is an inclined surface in a direction in which the screw thread is advanced, and a load flank which is an inclined surface in a direction in which the screw thread is retracted, the no-load flank and the load flank being formed at both sides of the screw thread, in which the no-load flank of the screw thread includes: a first tangential portion which abuts against an arc portion formed at a thread crest of an opposing fastening object; and a second tangential portion which has a preset angle with respect to the first tangential portion and abuts against the arc portion.

The present invention provides a looseness-prevention screw thread structure including a screw thread having a predetermined pitch, a no-load flank which is an inclined surface in a direction in which the screw thread is advanced, and a load flank which is an inclined surface in a direction in which the screw thread is retracted, the no-load flank and the load flank being formed at both sides of the screw thread, in which the no-load flank of the screw thread includes: a first tangential portion which abuts against an arc portion formed at a thread crest of an opposing fastening object; and a second tangential portion which has a preset angle with respect to the first tangential portion and abuts against the arc portion.