Method of winding an electrical coil as successive oblique layers of coil turns

In a method of oblique winding of an electrical coil by winding said coil as successive parallel oblique layers of coil turns perpendicular to a winding axis of a coil former and effecting a change from one turn to the next turn by axially offsetting said one turn from said next turn, the improvement wherein:

• said step of winding said coil as successive parallel oblique layers of coil turns comprises;
• winding coil turns in the form of a triangle about said winding axis, having in radial cross-section through said winding axis one side as a base of said triangle situated against said coil former, a second side constituting an oblique rising edge and a third, oppositely oblique side, and
• winding sequentially alternately oppositely upward and downward oblique coil turn layers parallel to said third, oppositely oblique side thereby causing the coil to advance progressively along the axis of the coil former, such that a half-section of said coil in a radial plane containing said winding axis is in the form of a trapezium with said coil constituting a self-supporting stable mechanical assembly, and with coil turns on oblique sides of the trapezium, with the exception of two turns at respective opposite ends of a longer parallel side of the trapezium, resting on two turns in a coil layer extending parallel to the winding axis, and wherein a point at which said oblique rising edge meets said third oppositely oblique side defines the radial extremity of said trapezium, with each coil turn of the rising edge except for a first coil turn resting on two successive turns in the same layer parallel to the winding axis, the first of said turns being a previous turn of a rising edge,
• skipping placement of a coil turn n for making an adjustment tap during one of downwardly oblique coil turn winding and upwardly oblique coil turn winding;
• thereby leaving one turn location free, and continuing winding of succeeding coil turns from said one turn location free until reaching the last coil turn of a succeeding alternately oppositely upward oblique coil turn layer, and thereafter placing said skipped turn n at the top of the upwardly wound oblique coil turn layer at the top of the trapezium, and further continuing said coil winding in a succeeding downwardly oblique coil turn layer.