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

• US 5,305,961 A
• Filed: 06/12/1992
• Issued: 04/26/1994
• Est. Priority Date: 06/14/1991
• Status: Expired due to Fees

• Current Assignee: Alstom Holdings (Alstom SA)
• Original Assignee: GEC Alsthom SA (Alstom SA)
• Inventors: Errard, Alain, Bourgeon, Roger
• Primary Examiner(s): Falik, Andrew M.
• Application Number:
  US07/897,642
• Time in Patent Office: 683 Days
• Field of Search: 242/7.03, 242/7.08, 242/7.09, 29/605
• US Class Current: 242/447.1
• CPC Class Codes: H01F 2027/2842 Wire coils wound in conical zigzag to reduce voltage between winding turns
• CPC Class Codes: H01F 27/2823 Wires H01F27/2866 takes precedence
• CPC Class Codes: H01F 41/086 in a special configuration on the former, e.g. orthocyclic coils or open mesh coils
• CPC Class Codes: Y10S 174/22 Winding per se
• CPC Class Codes: Y10T 29/49071 by winding or coiling

Abstract

An electrical coil is created by winding an electrical coil as successive parallel oblique layers of coil turns projecting radially outwardly from a coil former about which the coil turns are wound with the coil turns positioned radially outward of the coil former axis. The winding forms in radial cross-section, a triangle having a base situated against the coil former, a second side constituting an oblique rising edge and a third oppositely oblique side. Alternately upward and downward oblique coil turn layers are successively wound to advance the coil progressively along the axis of the former. To effect a connection to an adjustment tap on a turn n which in normal winding would not be on the radially outer layer of coil turns extending parallel to the winding axis but rather buried within the coil, such succeeding coil turn n of either the downwardly oblique coil turn winding layer or upward oblique coil turn winding layer extending parallel to the third side of the trapezium is left free, and the turn n which would be normally buried in the coil is placed in the last coil turn space of the next upwardly oblique coil turn layer on the outer periphery of the electrical coil to properly position its adjustment tap.

Claims

1. 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.