Automated fabrication of wiring harness having continuous straight and contrahelic sections

• US 5,052,450 A
• Filed: 04/12/1990
• Issued: 10/01/1991
• Est. Priority Date: 04/12/1990
• Status: Expired due to Fees

• Current Assignee: Grumman Aerospace Corporation (Northrop Grumman Corporation)
• Original Assignee: Grumman Aerospace Corporation (Northrop Grumman Corporation)
• Inventors: Williams, Stuart J.
• Primary Examiner(s): Larson, Lowell A.
• Application Number:
  US07/507,787
• Time in Patent Office: 537 Days
• Field of Search: 140/39, 140/47, 140/115, 140/149, 57/90, 57/314
• US Class Current: 140/149
• CPC Class Codes: H01B 13/0257 being a perforated disc

Abstract

The present invention offers a machine which is capable of creating contrahelic wound harness sections existing with continuously disposed straight lay wire sections. The invention avoids the necessity of interposing electrical connectors between the contrahelic and straight lay sections thereby vastly improving the reliability and cost considerations of a complex multiwire harness. Pulleys are driven in synchronism by microprocessor-controlled stepper motors. The pulley winding the contrahelic layer may be moved transversely by a rack and pinion gear arrangement, the pinion gear being stepper motor driven by the microprocessor so that a correct transversal rate is achieved during contrahelic winding.

Claims

1. A wire-twisting machine for fabricating continuous straight and contrahelically wound sections having:

means for securing a first wire between first and second fixed end means;

first and second coaxially spaced pulley wheels located inwardly of the fixed points and having central openings therein through which the first wire passes;

stationary guide means located between the second pulley wheel and the second fixed end means, the guide means having a coaxially located central opening for allowing the first wire to pass therethrough;

a second wire secured to a radially outward point on the first pulley wheel and positioned in parallel spaced relation to the first wire;

radially outward openings formed in the second pulley wheel and the guide means for passing the second wire for securement to a point on the second fixed end means; and

means for rotating the pulley wheels in synchronous rotation wherein the second wire is helically wound around the first wire between the second pulley wheel and the guide means while the first and second wires remain parallel and unwound outwardly of the second pulley wheel and the guide means;

the improvement comprising;

means for movably mounting the second pulley wheel;

powered means connected to the mounting means for limitingly displacing the mounted second pulley wheel toward the first pulley wheel thereby achieving limited linear displacement of the second wire as it is wound around the first wire;

means for mounting the first pulley wheel;

spring means connected to the first pulley wheel mounting means for biasing the latter as to maintain tension on the second wire during a wire-twisting operation; and

wherein the motor means for driving the pulley wheels in synchronous rotation are motor driven.

2. The subject matter set forth in claim 1 together with bearing means engaging the pulley wheel perimeters for permitting their free synchronous rotation.

3. The subject matter set forth in claim 1 wherein the radially outward openings on the guide means are displaced by an equal radial distance from the central openings therein.

4. In an automated wire-twisting machine for fabricating continuous straight and contrahelically wound sections, the machine including:

means for securing a first group of wires between first and second fixed end means;

first and second coaxially spaced pulley wheels located inwardly of the fixed points and having central openings therein through which the first group of wires passes;

stationary guide means located between the second pulley wheel and the second fixed end means, the guide means having a coaxially located central opening for allowing the first group of wires to pass therethrough;

a second group of wires secured to a radially outward point on the first pulley wheel and positioned in parallel spaced relation to the first group of wires;

radially outward openings formed in the second pulley wheel and the guide means for passing the second wire group for securement to a point on the second fixed end means;

means for rotating the pulley wheels in synchronous rotation wherein the second group of wires is helically wound, as a layer, around the first group of wires between the second pulley wheel and the guide means while the first and second groups of wires remain parallel and unwound outwardly of the second pulley wheel and the guide means;

the improvement comprising;

means for movably mounting the second pulley wheel;

powered means connected to the mounting means for limitingly displacing the second pulley wheel toward the first pulley wheel thereby achieving limited linear displacement of the second wire group as it is wound around the first wire group;

means for mounting the first pulley wheel;

spring means connected to the first pulley wheel mounting means for biasing the latter as to maintain tension on the second wire group during a wire-twisting operation; and

wherein the means for driving the pulley wheels in synchronous rotation is motor driven.

5. The subject matter set forth in claim 4 together with bearing means engaging the pulley wheel perimeters for permitting their free synchronous rotation.

6. In a method for fabricating continuous straight and contrahelical wire sections including the steps:

securing a first group of wires between first and second fixed end points;

helically winding a median section of a second group of wires around the median section of the first wire group; and

bundling the outward ends of the first and second wire sets to form corresponding straightened sections;

the improvement comprising;

limitingly displacing the second pulley wheel toward the first pulley wheel thereby achieving limited linear displacement of the second wire group as it is wound around the first wire group;

biasing the first pulley wheel so as to maintain tension on the second wire group during a wire-twisting operation; and

driving the pulley wheels in synchronous rotation.

7. The method set forth in claim 6 together with the step of helically winding a median section of a third group of wires around the median section of the second wire group to form a contrahelical layer, the outward ends of the third group being then bundled with the bundled ends of the first and second wire group to form straight end sections.