Systems and methods for assembling an electro-acoustic transducer including a miniature voice coil

Patent metadata

Field	Value
Publication number	US-10425756-B2
Application number	US-201715472741-A
Country	US
Kind code	B2
Filing date	Mar 29, 2017
Priority date	Mar 29, 2017
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

A tool for arranging voice coil leadouts in a microspeaker comprises an expanding collet constructed and arranged for positioning at an interior of a bobbin having an inner diameter, the expanding collet including a hole that extends through an interior in a longitudinal direction of the expanding collet; a center pin extending through the hole of the expanding collet, the expanding collet applying a force against the inner diameter of the bobbin in response to a position of the center pin in the hole of the expanding collet relative to the interior of the expanding collet; and a forming mandrel including a hole that extends through an interior in a longitudinal direction of the forming mandrel. The expanding collet extends through the hole in, and coaxial with, the forming mandrel. The expanding collet rotates the bobbin about the longitudinal direction of the expanding collet relative to the forming mandrel to form helical leadout regions of a voice coil about the bobbin.

First claim

What is claimed is:

1. A tool for arranging voice coil leadouts in a microspeaker, comprising:
an expanding collet constructed and arranged for positioning at an interior of a bobbin having an inner diameter, the expanding collet including a hole that extends through an interior in a longitudinal direction of the expanding collet;
a center pin extending through the hole of the expanding collet, the expanding collet applying a force against the inner diameter of the bobbin in response to a position of the center pin in the hole of the expanding collet relative to the interior of the expanding collet; and
a forming mandrel including a hole that extends through an interior in a longitudinal direction of the forming mandrel, the expanding collet extending through the hole in, and is coaxial with, the forming mandrel, wherein the expanding collet rotates the bobbin about the longitudinal direction of the expanding collet relative to the forming mandrel to form helical leadout regions of a voice coil about the bobbin.

2. The tool of claim 1 , wherein the expanding collet includes a set of jaws that apply a force against an inner diameter of the bobbin in response to a force applied by the position of the center pin in the hole of the expanding collet.

3. The tool of claim 2 , wherein the collet jaws include a plurality of arms that extend radially away from the center pin toward the bobbin.

4. The tool of claim 2 , wherein the center pin includes a tapered portion that provides the force to the collet jaws.

5. The tool of claim 4 , wherein the hole extending through the expanding collet includes a tapered region that mates with the tapered portion of the center pin, wherein pulling the center pin in an axial direction into the hole causes the collet jaws to expand against the inner diameter of the bobbin so that the bobbin may be rotated against tension forces of the leadout regions.

6. The tool of claim 1 , further comprising a center pin handle coupled to the center pin and configured to actuate the center pin to clamp or release the inner diameter of the bobbin.

7. The tool of claim 6 , further comprising a collet knob coupled to the expanding collet for rotating the collet.

8. The tool of claim 1 , further comprising two guide pins that extend from the forming mandrel for guiding conductive wiring of the voice coil during formation of the helical leadout regions.

9. The tool of claim 1 , further comprising a guide insert positioned about the forming mandrel and is stationary relative to the expanding collet for receiving conductive wiring of the voice coil and forming the helical leadout regions.

10. A tool for positioning voice coil leadouts in a microspeaker, comprising:
an expanding mandrel constructed and arranged for positioning at an interior of a bobbin having an inner diameter, the expanding mandrel including a hole that extends through an interior in a longitudinal direction of the expanding mandrel;
a center pin extending through the hole of the expanding collet, a portion of the expanding mandrel applying a force against the inner diameter of the bobbin in response to a position of the center pin in the hole of the expanding mandrel relative to the interior of the expanding mandrel;
a coil spring positioned about the center pin and that abuts an opposite end of the expanding mandrel as an end at which the portion of expanding mandrel applies the force against the inner diameter of the bobbin; and
a spring perch that causes the coil spring to compress between the spring perch and the expanding mandrel, wherein the expanding mandrel can be separated from the bobbin and the bobbin can be rotated about the longitudinal direction of the expanding mandrel relative to the expanding mandrel to form helical leadout regions of a voice coil about the bobbin.

11. The tool of claim 10 , wherein the coil spring in a partially compressed state provides a force to the center pin that translates the force to jaws of the expanding mandrel applying the force against the inner diameter of the bobbin to lock the bobbin to the collet.

12. The tool of claim 10 , further comprising a guide insert positioned about a portion of the expanding mandrel for positioning conductive wiring of the voice coil during formation of the helical leadout regions, the guide insert including a vertical guide extending along a flat sidewall of the expanding mandrel to prevent rotation of the guide insert during formation of the voice coil leadouts.

13. The tool of claim 12 , wherein the guide insert remains with and is secured to a sleeve after formation of the helical leadout regions and assembly of the microspeaker.

14. The tool of claim 10 , wherein the expanding mandrel includes a set of jaws that apply a force against an inner diameter of the bobbin in response to a force applied by the position of the center pin in the hole of the expanding mandrel.

15. The tool of claim 10 , further comprising a lock mechanism for compressing the coil spring to release the inner diameter of the bobbin and allow the formation of the helical leadout regions of a voice coil.

16. The tool of claim 10 , further comprising a bobbin rotation stage that rotates the bobbin when the jaws release the bobbin, and holds the expanding mandrel in a stationary position during rotation of the bobbin.

17. A tool for positioning voice coil leadouts in a microspeaker, comprising:
a mandrel constructed and arranged for positioning in an interior of a bobbin having an inner diameter;
a center pin extending through a hole of the mandrel, the center pin having a base positioned in the interior of the bobbin;
a coil spring positioned in the hole of the mandrel and about the center pin; and

and
a compliant ring positioned in the interior of the bobbin between the base of the center pin and the mandrel, the compliant ring constructed and arranged to expand in a radial direction away from the center pin toward the bobbin when the coil spring is in an initial state.

18. The tool of claim 17 , wherein the base is at one end of the center pin, and the tool further comprises a spring perch at the other end of the center pin, the spring perch constructed and arranged to apply a force to the coil spring to at least partially compress the coil spring between the spring perch, the mandrel, and an inner diameter of the interior of the bobbin.

19. The tool of claim 17 , further comprising a helix formation part positioned about the bobbin that rotates about the bobbin to form helical leadout regions of a voice coil about the bobbin.

20. The tool of claim 17 , further comprising a retainer in the hole of the mandrel to hold the leadout ends in a vertical alignment at final assembly when placing the voice coil in a sleeve.

21. A method for assembling an electro-acoustic driver, comprising:
positioning an expanding collet of a tool at an interior of a bobbin having an inner diameter, the expanding collet including a hole that extends through an interior in a longitudinal direction of the expanding collet;
extending a center pin of the tool through the hole of the expanding collet;
applying by the expanding collet a force against the inner diameter of the bobbin in response to a position of the center pin in the hole of the expanding collet relative to the interior of the expanding collet;
extending a forming mandrel of the tool including a hole through an interior in a longitudinal direction of the forming mandrel; and
rotating the bobbin about the longitudinal direct

Assignees

• Bose Corp

Inventors

• Guthy Csaba
• Beverly David W

Classifications

• H04R1/1033

  Cables or cables storage, e.g. cable reels (cord reels per se H02G11/02; arrangements for storing and repeatedly paying-out and re-storing lengths of conductors or cables B65H75/34; extensible conductors or cables, e.g. self-coiling cords H01B7/06) · CPC title

• H04R31/00 Primary

  Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor {(manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182)} · CPC title

• H04R31/006 Primary

  Interconnection of transducer parts (of diaphragm and outer suspension by moulding H04R31/003) · CPC title