SCREW TIGHTENING STRUCTURE, SCREW AND SCREW TIGHTENING TOOL Russian patent published in 2014 - IPC F16L23/00 

FIELD: machine building.

SUBSTANCE: invention relates to fasteners, particularly, to splines for threaded joints tightening. In compliance with this invention, outer peripheral ends of torque transfer section of locating ledges are brought in contact with surfaces of lateral wall of spline torque transfer section. Tightening torque is transferred to screw via force application points that make the contact sections. Here, end face surface is perpendicular to the spline axial line while its shape includes the point of force application perpendicular to the surface while power angle makes zero degree or less. Therefore force perpendicular to the surface is applied to the spline lateral wall tangentially to axial line or inward. Compared with common case wherein force perpendicular to the surface acts outward at 0°<θ decreased the probability of disengagement that causes tightening tool from spline.

EFFECT: minor deformation or damage of splines, ease of tightening.

12 cl, 10 dwg