Diaphragm-edge integral moldings for speakers and acoustic transducers comprising same

• US 5,744,761 A
• Filed: 06/28/1994
• Issued: 04/28/1998
• Est. Priority Date: 06/28/1993
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Murata, Kousaku, Ogura, Takashi
• Primary Examiner(s): Dang, Khanh
• Application Number:
  US08/266,924
• Time in Patent Office: 1,400 Days
• Field of Search: 181/167, 181/169, 181/170, 181/171, 181/172, 181/173, 181/174
• US Class Current: 181/167
• CPC Class Codes: H04R 2231/001 Moulding aspects of diaphragm or surround
• CPC Class Codes: H04R 2231/003 Manufacturing aspects of the outer suspension of loudspeaker or microphone diaphragms or of their connecting aspects to said diaphragms
• CPC Class Codes: H04R 2307/025 Diaphragms comprising polymeric materials
• CPC Class Codes: H04R 2307/029 Diaphragms comprising fibres
• CPC Class Codes: H04R 2307/204 Material aspects of the outer suspension of loudspeaker diaphragms
• CPC Class Codes: H04R 31/003 for diaphragms or their outer suspension
• CPC Class Codes: H04R 7/125 comprising a plurality of superposed layers in contact
• CPC Class Codes: H04R 7/20 Securing diaphragm or cone resiliently to support by flexible material, springs, cords, or strands

Abstract

A diaphragm for speakers comprises a self-support, shaped body including a tightly woven synthetic polymer fiber cloth substrate which has at least a diaphragm portion and edge portion shaped integrally with and extending from the diaphragm portion. The diaphragm portion of the cloth substrate had a polymer resin at least partially impregnated therein and the edge portion has a relatively flexible polymer material at least partially impregnated therein so that the edge portion is lower in stiffness than the diaphragm portion. The diaphragm-edge integral molding is fabricated by applying the respective types of polymers to the diaphragm and edge portions of the cloth substrate and subjecting the applied substrate to hot pressing in a mold capable of forming the integral molding. When applied as dynamic speakers, the integral molding exhibits a broad frequency band, low distortion rates and high sound quality. The stiffness difference between the diaphragm and edge portions may be created by using one type of thermoplastic resin which is applied to the diaphragm and edge portions in different amounts.

Claims

1. A diaphragm for speakers which comprises a self-supporting, shaped body including a tightly woven synthetic polymer fiber cloth substrate which has, at least, a diaphragm portion and an edge portion shaped integrally with and extending from said diaphragm portion wherein said diaphragm portion of said cloth substrate has a polymer resin at least partially impregnated thereto in order to impart stiffness to said diaphragm portion and said edge portion has a flexible polymer material at least partially impregnated therein so that said edge portion is lower in stiffness than said diaphragm portion,

wherein said cloth substrate has a weave structure which consists of fine fibers and thick fibers, said thick fibers being woven in said cloth substrate at intervals in vertical and horizontal directions to impart appropriate stiffness to said cloth substrate.

2. A diaphragm according to claim 1, wherein said thick fibers are woven at equal intervals to make check patterns of said thick fibers in said cloth substrate.

3. A diaphragm according to claim 1, herein said fine fibers has a denier of from 20 to 200.

4. A diaphragm according to claim 1, wherein said cloth substrate consists of polyester fibers.

5. A diaphragm according to claim 1, wherein said cloth substrate consists of polyamide fibers.

6. A diaphragm according to claim 1, wherein said polymer resin is at least partially impregnated in said cloth substrate and consists of a thermosetting resin.

7. A diaphragm according to claim 6, wherein said thermosetting resin is an epoxy resin.

8. A diaphragm according to claim 1, wherein said polymer resin is at least partially impregnated in said cloth substrate and consists of a thermoplastic resin.

9. A diaphragm according to claim 8, wherein said thermoplastic resin is an acrylic resin.

10. A diaphragm according to claim 8, wherein said thermoplastic resin is a urethane resin.

11. A diaphragm according to claim 1, wherein said flexible polymer material is at least partially impregnated in said cloth substrate and consists of a rubber material.

12. A diaphragm according to claim 1, wherein said diaphragm portion has a high-band threshold frequency not less than 20,000 Hz.

13. A diaphragm according to claim 1, further comprising a reinforcing layer formed on said diaphragm portion in a pattern corresponding to said diaphragm portion.

14. A diaphragm according to claim 13, wherein said reinforcing layer is made of a tightly woven synthetic polymer fiber cloth impregnated with a thermoplastic resin.

15. A diaphragm according to claim 14, wherein said reinforcing layer is made of a plurality of the impregnated polymer fiber cloth pieces.

16. A diaphragm according to claim 13, wherein said reinforcing layer consists of a film of a metal or alloy vacuum deposited on said diaphragm portion.

17. A diaphragm according to claim 13, wherein said reinforcing layer consists of a film of diamond.

19. A diaphragm according to claim 1, wherein a damping agent is applied to said shaped body whereby unnecessary resonance is eliminated.

18. A diaphragm for speakers which comprises a self-supporting, shaped body including a tightly woven synthetic polymer fiber cloth substrate which has, at least, a diaphragm portion and an edge portion shaped integrally with and extending from said diaphragm portion wherein said diaphragm portion of said cloth substrate has a polymer resin at least partially impregnated thereto in order to impart stiffness to said diaphragm portion and said edge portion has a flexible polymer material at least partially impregnated therein so that said edge portion is lower in stiffness than said diaphragm portion,

wherein said cloth substrate is made of fibers individually coated with a thermoplastic polymer when spun.

20. A diaphragm according to claim 18, wherein said fibers consist of a polyester resin.

21. A diaphragm according to claim 18, wherein said fibers consist of a polyamide resin.

22. A diaphragm for closed speakers which comprises self-supporting, shaped body including a tightly woven synthetic polymer fiber cloth substrate which has, at least, a diaphragm portion and an edge portion shaped integrally with and extending from said diaphragm portion wherein said diaphragm and edge portion of said cloth substrate each have a thermoplastic polymer resin at least partially, uniformly impregnated therein in a respective amount sufficient to control a high-cut frequency at a predetermined level,

wherein said cloth substrate has a weave structure which consists of fine fibers and thick fibers, said thick fibers being woven in said cloth substrate at intervals in vertical and horizontal directions to impart appropriate stiffness to said cloth substrate.

23. A diaphragm according to claim 22, wherein said amount is in the range of from 10 to 20 g/m² and said high-cut frequency is in the range of from 3.0 to 4.0 Hz.

24. A diaphragm for speakers which comprises:

a self-supporting, shaped body including a tightly woven cloth substrate which is made of synthetic fibers selected from the group consisting of polyester fibers and polyamide fibers and has, at least, a diaphragm portion and an edge portion shaded integrally with and extending from said diaphragm portion;

wherein said diaphragm portion of said cloth substrate has a polymer resin at least partially impregnated therein in order to impart stiffness to said diaphragm portion, said polymer resins selected from the group consisting of epoxy resins, acrylic resins and urethane, resins, and said edge portion has a rubber material at least partially impregnated therein so that said edge portion is lower in stiffness than said diaphragm portion,

wherein said cloth substrate has a weave structure which consists of fine fibers and thick fibers, said thick fibers being woven in said cloth substrate at intervals in vertical and horizontal directions to impart appropriate stiffness to said cloth substrate.

25. A diaphragm according to claim 24, wherein said thick fibers are woven at equal intervals to make check patterns of said thick fibers in said cloth substrate.

26. A diaphragm according to claim 24, wherein said fine fibers have a denier of from 20 to 200.

27. A diaphragm according to claim 24, wherein said diaphragm portion has a high-band threshold frequency not less than 20,000 Hz.

28. A diaphragm according to claim 24, further comprising a reinforcing layer on said diaphragm portion in a pattern corresponding to said diaphragm portion.

29. A diaphragm according to claim 28, wherein said reinforcing layer consists of a film of a metal or alloy on said diaphragm portion.

30. A diaphragm according to claim 28, wherein said reinforcing layer consists of a film of artificial diamonds.

31. A diaphragm according to claim 24, wherein a damping agent is applied to said shaped body.