GB2291883A - Resinous material and units fabricated therefrom - Google Patents
Resinous material and units fabricated therefrom Download PDFInfo
- Publication number
- GB2291883A GB2291883A GB9414817A GB9414817A GB2291883A GB 2291883 A GB2291883 A GB 2291883A GB 9414817 A GB9414817 A GB 9414817A GB 9414817 A GB9414817 A GB 9414817A GB 2291883 A GB2291883 A GB 2291883A
- Authority
- GB
- United Kingdom
- Prior art keywords
- enclosure
- rubber
- exterior
- mineral
- interior volume
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
- C08K3/013—Fillers, pigments or reinforcing additives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
- C08L67/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Details Of Audible-Bandwidth Transducers (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
Abstract
A material for use in the manufacture of an acoustic unit such as a loud speaker enclosure comprises a polyester casting resin incorporating a mineral bulking material composed of a mixture of particles, the mixture including particles lying in a range of particle sizes together with strands or crumbs of rubber or a rubber like material. The bulking material can include hollow bead components. Preferably the proportion by weight of mineral to rubber crumb lies in the range 80/20 to 90/10 and the proportion of mineral/rubber mix to resin lies in the range 80/20 to 70/30. An acoustic enclosure fabricated from the material has at least one interior volume; the thickness of the wall between the interior volume and the exterior of the enclosure being according to one version substantially uniform and in an alternative version non-uniform in a linear direction along the exterior of the enclosure.
Description
MATERIAL FOR FABRICATION AND UNITES FABRICATED THEREFROM
This invention relates to material for fabrication and units fabricated therefrom.
It is particularly, though not exclusively, concerned with the use of the material in the fabrication of acoustic units such as loudspeaker enclosures.
Conventional materials used for the enclosures of current loudspeaker designs include wood or wood based materials such as block or chip board. While such materials are readily worked and machined their use does not readily result in acoustically satisfactory enclosures. Conventional loudspeaker enclosures are usually box like in form resulting in an internal shape which lead to the generation of several resonant frequencies. These require the provision of sound deadening or dampening means.
The design of a loudspeaker enclosure involves consideration of a number of factors. There is a need for the enclosure to provide for reasonable reproduction of a range of frequencies using a number of loudspeaker units. The type and number of loudspeaker units contained within an enclosure will establish the frequency range but colouration imposed by the enclosure should be kept to a minimum. In addition there are constraints arising from the size of the enclosure.
For certain applications a large enclosure is deemed desirable. Such enclosures must be sufficiently strong to provide for adequate stiffening, support for the loudspeakers and related circuitry and to provide for such porting and internal damping as is necessary.
According to a first aspect of the present invention there is provided a material for for use in the manufacture of an acoustic unit such as a loud speaker enclosure comprising a polyester casting resin incorporating a mineral bulking material composed of a mixture of particles, the mixture including particles lying in a range of particle sizes together with strands or crumbs of rubber or a rubber like material.
According to a first preferred version of the first aspect of the present invention the bulking material includes hollow bead components.
According to a second preferred version of the present invention or the first preferred version thereof wherein the proportion by weight of mineral to rubber crumb lies in the range 80/20 to 90/10 and the proportion of mineral/rubber mix to resin lies in the range 80/20 to 70/30.
According to a second aspect of the present invention therein provided an acoustic enclosure fabricated from a material according to the first aspect or any preferred version thereof having at least one interior volume; the thickness of the wall between the interior volume and the exterior of the enclosure being substantially uniform in a linear direction along the exterior of the enclosure.
According to a third aspect of the present invention there is provided an acoustic enclosure fabricated from a material according to the first aspect having at least one interior volume; the thickness of the wall between the interior volume and the exterior of the enclosure being non-uniform in a linear direction along the exterior of the enclosure.
According to a fourth aspect of the present invention there is provided an acoustic enclosure according to the second or third aspects wherein the enclosure serves to define at least two separate interior volumes adapted to have a loudspeaker located therein, each volume opening through a port in the enclosure to the exterior of the enclosure or to another interior volume.
An exemplary embodiment of the invention will now be described from two aspects, with reference to the accompanying drawings of a loudspeaker enclosure of which:
Figure 1 is a front elevation:
Figure 2 is a side elevation;
Figure 3 is a sectional elevation on line ffl-ffl of Figure 1.
First Aspect- material
A material according to the first aspect of the present invention is made up of a cast fabrication. The casting is undertaken in a mould to produce the enclosure described hereafter in connection with Figures 1 to 3. The interior of the mould is provided with a standard polyester gel coat (such as Polycor 9101). A mix is then prepared made up of a mineral bulking agent including hollow beads (such as Advanced Materials product Number FL 2/300 marketed under the trade mark 'FLOWBEAD 3000'). To this mixture there is then added a rubber crumb derived from recycled tyre material.
A standard polyester casting resin (such as Neste G 103 E) is then added to the mix. The proportions of the material used depends to a substantial extent on the end product involved. However in practice it has been found that the following range of mixtures by weight are suitable: mineral 80%/rubber crumb 2070 to mineral 9070/rubber crumb 10%.
The proportion of resin then added in the range: mineral/rubber 80% - resin 20% to mineral/rubber 70% - resin 30%.
However it is stressed that the optimum proportions depends on the final product required.
Any further mechanical elements to be cast into the enclosure are located in the mould. The prepared mix with added catalyst is then deposited on the gel coat in the mould and allowed to polymerise. The contents of the mould are demoulded and post-cured for a period of up to 4 hours.
The post-cured enclosure is then trimmed, assembled and polished prior to the insertion of loud speaker units and other components.
Second aspect - fabrication
The figures variously show freshly moulded enclosure 11 with two ports 12, 13 for, respectively, loudspeakers 14, 15. Enclosure 11 has an outside gel coated surface and is made up of sides 16, 17, top 18, bottom 19 and back 20 formed as an integral fabrication.
The interior of the enclosure 11 is made up of two independent plenums 21, 22 which serve to house, respectively, loudspeakers 14, 15 in relative acoustic isolation. To inhibit the formation of standing waves in the enclosure the wall thickness is varied so that the plenums 21, 22 while being each being of controlled volume are unsymmetrical in form. Thus the thickness of back 20 in the vicinity of plenum 12 in the direction of axis 23 is not uniform.
While the exemplary embodiment refers to an enclosure with non-uniform wall thickness to ameliorate. for example, the generation of specific internal resonant frequencies the material of the present invention can also be used to provide enclosures with substantially uniform wall thickness which still provide an improved acoustic performance over existing enclosures fabricated from conventional material.
In fabricating a loudspeaker enclosure from the material of the present invention it has been found that an enclosure of virtually any shape is readily fabricated and provides for a sound output with minimum colouration. The fabrication process provides all the advantages to be obtained from the use of a moulded material.
This is particularly significant in comparison with enclosures fabricated from currently used wood or wood based sheet materials.
The outer side of an enclosure according to the present invention is readily finished by veneering, spraying, gel coating or whatever.
The use of a moulding process further provides for the ready incorporation of other simple or complex shaped components and the protection of circuitry..
The use of strands or crumbs of rubber or rubber like material has been found to provide significant advantages in an acoustic context. The exemplary embodiment refers to a loudspeaker enclosure. However other applications where acoustic behaviour is significant are readily supplied such as a shelf or unit for supporting
or housing acoustically sensitive components.
Claims (8)
1 A material for use in the manufacture of an acoustic unit such as a loud
speaker enclosure comprising a polyester casting resin incorporating a
mineral bulking material composed of a mixture of particles, the mixture
including particles lying in a range of particle sizes together with strands
or crumbs of rubber or a rubber like material.
2 A material as claimed in Claim 1 wherein the bulking material includes
hollow bead components.
3 A material as claimed in Claim 1 or Claim 2 wherein the proportion by
weight of mineral to rubber crumb lies in the range 80/20 to 90/10 and the
proportion of mineral/rubber mix to resin lies in the range 80/20 to 70/30.
4 A material for use in the manufacture of an acoustic unit as hereinbefore
described with reference to the accompanying drawing.
5 An acoustic enclosure fabricated from a material according to any
preceding claim having at least one interior volume; the thickness of the
wall between the interior volume and the exterior of the enclosure being
substantially uniform in a linear direction along the exterior of the
enclosure.
6 An acoustic enclosure fabricated from a material as claimed in any of
preceding claims 1 to 4 having at least one interior volume; the thickness
of the wall between the interior volume and the exterior of the enclosure
being non-uniform in a linear direction along the exterior of the enclosure.
7 A loud speaker enclosure comprising an acoustic enclosure according Claim
5 or Claim 6, the enclosure serving to define at least two separate interior
volumes adapted to have a loudspeaker located therein, each volume
opening through a port in the enclosure to the exterior of the enclosure or
to another interior volume.
8 A loudspeaker enclosure as hereinbefore described with reference to the
accompanying drawings.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9414817A GB2291883B (en) | 1994-07-22 | 1994-07-22 | Material for fabrication and units fabricated therefrom |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9414817A GB2291883B (en) | 1994-07-22 | 1994-07-22 | Material for fabrication and units fabricated therefrom |
Publications (3)
Publication Number | Publication Date |
---|---|
GB9414817D0 GB9414817D0 (en) | 1994-09-14 |
GB2291883A true GB2291883A (en) | 1996-02-07 |
GB2291883B GB2291883B (en) | 1998-05-06 |
Family
ID=10758737
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB9414817A Expired - Fee Related GB2291883B (en) | 1994-07-22 | 1994-07-22 | Material for fabrication and units fabricated therefrom |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2291883B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6306961B1 (en) | 1997-04-24 | 2001-10-23 | Kaneka Corporation | Thermoplastic resin composition having impact resistance |
GB2428532A (en) * | 2005-07-22 | 2007-01-31 | Hosiden Besson Ltd | An acrylic resin/mineral loudspeaker cabinet |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1053270A (en) * | 1965-02-18 | |||
JPS52132805A (en) * | 1976-04-30 | 1977-11-07 | Toshiba Corp | Structural material for acoustic instrument |
EP0308871A2 (en) * | 1987-09-21 | 1989-03-29 | Mitsubishi Rayon Co., Ltd. | Thermoplastic polyester resin composition |
-
1994
- 1994-07-22 GB GB9414817A patent/GB2291883B/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1053270A (en) * | 1965-02-18 | |||
JPS52132805A (en) * | 1976-04-30 | 1977-11-07 | Toshiba Corp | Structural material for acoustic instrument |
EP0308871A2 (en) * | 1987-09-21 | 1989-03-29 | Mitsubishi Rayon Co., Ltd. | Thermoplastic polyester resin composition |
Non-Patent Citations (1)
Title |
---|
WPI Abstract Accession No 77-90760Y/51 & JP 52 132 805 A * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6306961B1 (en) | 1997-04-24 | 2001-10-23 | Kaneka Corporation | Thermoplastic resin composition having impact resistance |
GB2428532A (en) * | 2005-07-22 | 2007-01-31 | Hosiden Besson Ltd | An acrylic resin/mineral loudspeaker cabinet |
Also Published As
Publication number | Publication date |
---|---|
GB2291883B (en) | 1998-05-06 |
GB9414817D0 (en) | 1994-09-14 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20010722 |