Screw axial pull-out strength test loading device

Abstract

The invention discloses a screw axial pull-out strength test loading device. The screw axial pull-out strength test loading device comprises a middle connecting block, wherein the middle connecting block is of a square-frame shaped structure; an upper connection hole and a lower connection hole are respectively formed in the middle of a top plate and in the middle of a bottom plate of the middle connecting block in the direction perpendicular to the top plate and the bottom plate; the lower part of an upper connecting rod is fixedly connected with the upper connecting hole; a disc shaped structure of a movable connecting block is supported on the top surface of the bottom plate of the middle connecting block; an inverted truncated cone of the movable connecting block penetrates through thelower connection hole; the movable connecting block is suspended on the bottom plate of the middle connecting block through the disc shaped structure; the top part of one of bottom connecting rods isfixed in a fixing hole of the inverted truncated cone. According to the device, transmission of load through the head part of a screw is ensured, and the direction is axially collinear to the longitudinal direction of the screw.

Description

technical field [0001] The invention relates to a loading device for a screw axial pull-out force test. Background technique [0002] Fractures are one of the most common conditions in orthopedics. Metal bone screws provide surgeons with a means of bone fixation and are currently one of the most common means of treating fractures. After the screw is implanted in the human body, in addition to bearing the working load, whether it can be firmly fixed on the broken bone is one of the important performances of screw healing. The American Society for Materials issued a document ASTMF543 that stipulates the standard specifications and test methods for medical metal bone screws. Appendix A3 specifies the test method for the axial pull-out force of medical bone screws. my country has also formulated the industry standard YY / T 1504-2016, the specification Test method for extraction force of medical bone screws. The schematic diagram of the screw pull-out force test device is provid...

AI Technical Summary

Problems solved by technology

[0003] At present, it is generally used in the industry to directly clamp the screw head for pull-out test, but this is easy to clamp the screw head and make it impossible to measure the screw pull-out force, and the effect is very unsatisfactory.

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