Patent ID: 6910654

Claim:
An apparatus for winding a multi-layer coil in a winding space of a bobbin having a center pillar, a small flange connected to one end of the center pillar and a large flange connected to the other end of the center pillar, the winding space being defined outside the center pillar between both flanges and having a trapezoidal cross-section in a plane cut through a center axis of the center pillar, the winding apparatus comprising: a rotating device for rotating the bobbin around the center axis thereof; a wire feeder for supplying a wire forming the multi-layer coil, the wire feeder being reciprocally moved in a direction parallel to the center axis for winding each layer of the coil; and a position setter for setting a turning position where a layer of the coil wound from the large flange toward the small flange is switched to a next layer wound from the small flange toward the large flange, the position setter being disposed and held radially outside an outer peripheral edge of the small flange so that the position setter is free to move axially with respect to the small flange wherein: inner layers of the coil are wound around the center pillar in a space between the small flange and the large flange until a height of the inner layers reaches a height of the small flange, and thereafter outer layers are wound on the inner layers while shifting the turning position set by the position setter toward the large flange by predetermined wire-pitches for each layer, thereby forming the multi-layer coil encompassed within the winding space having the trapezoidal cross-section.