SCREW WITH EASY INSERTION Russian patent published in 2020 - IPC F16B25/04 

FIELD: machine building.

SUBSTANCE: invention relates to a screw, which is especially suitable for wood-based material or composite material. Screw comprises an end; a head for accommodating a tool for rotating said screw about a rotational axis of the screw; and thread passing from thread start point at end to head. Thread has depth (w) of thread. Thread has first average coefficient (Κ₁(θ)) of increasing said thread depth (w) relative to rotation angle (θ) about axis of rotation along first half of revolution from said thread start point; and second average coefficient (Κ₂(θ)) for increasing said thread depth (w) with respect to angle (θ) of rotation about said axis of rotation along second half of revolution from said thread start point immediately following said first half of revolution. Said first average coefficient (Κ₁(θ)) of increase is at least three times larger than said second average coefficient (Κ₂(θ)) of increase.

EFFECT: invention is aimed at reduction of forces for its introduction into material.

3 cl, 14 dwg