US3513269A - Earform mold for supporting acoustic apparatus on a wearer's ear and method of making the mold - Google Patents

Description

May 19, 1970 D. R. WILSON 3,513,269

EARFORM MOLD FOR SUPPORTING ACOUSTIC APPARATUS ON A WEARER'S EAR AND METHOD OF MAKING THE MOLD Filed Jan. 26, 1967 ACOUSTIC APPARATUS INVENTOR DONALD R. WILSON BY QC 33k ATTORNEY United States Patent 01 ice 3,513,269 Patented May 19, 1970 3,513,269 EARFORM MOLD FOR SUPPORTING ACOUSTIC APPARATUS ON A WEARERS EAR AND METH- OD OF MAKING THE MOLD Donald R. Wilson, Santa Cruz, Calif., assignor to Pacific Plantrouics, Inc., Santa Cruz, Califi, a corporation of California Filed Jan. 26, 1967, Ser. No. 612,018 Int. Cl. H04r 25/00 US. Cl. 179-107 5 Claims ABSTRACT OF THE DISCLOSURE An earform casting which conforms to the shape of the wearers outer ear and which includes potting means within a generally preshaped self-contained sack to simplify the custom casting of the shape of the wearers outer ear.

BACKGROUND OF THE INVENTION Certain devices for supporting acoustical apparatus on the wearers head include a plastic casting of the wearers outer ear that attaches to and supports the apparatus. The disadvantage encountered with castings of this type is that the outer ear of each individual wearer is custom-fitted first by using quick setting compounds poured directly into or around the ear to produce a positive form and then, using transfer molding processes, by casting and machine-finishing the final casting. Such methods for custom fitting each individual wearer commonly require manual fitting and polishing with concomitant expense, inconvenience and delay and, as a result, have not been widely used.

SUMMARY OF THE INVENTION In accordance with the illustrated embodiment of the present invention, these disadvantages are overcome by forming the finished casting of a two-part activatable potting compound which is contained in a liquid state in a pliable sack that is preformed to a general outer ear shape. Upon activation of the potting compound the sack need only be gently pressed into the shape of the outer ear of a wearer during a brief curing period.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of an earmold sack which is in the general shape of the interior region of the outer ear and which is filled with a potting compound in a liquid or moldable state with an acoustic tube which passes through the sack and including a capsule of an activator ingredient within the inner chamber of the sack; FIG. 2 is a cross-sectional view of a custom-molding casting showing the enclosing sack and the associated transducer, acoustic tube structure and internal capsule of potting compound activator; and FIG. 3 is a sectional view of an earmold casting shaped about the exterior region of the outer ear showing the acoustic apparatus and acoustic receiver tube attached and positioned about the outer ear of the wearer.

DESCRIPTION OF THE PREFERRED EMBODI- MENT OF THE INVENTION Referring now to FIG. 1, there is shown an outer sack 9 formed in the general shape of the interior region of the outer ear and including an acoustic channel 11 that runs from the tip 13 which is adapted to fit into the wearers ear canal through the body of the outer sack 9 to the apparatus attachment bushing 15. A resilient and biologically inert material such as silicone rubber, or the like, is preferred for the outer sack material to insure pliable conformation of the sack to the outer ear of the wearer and to insure that the potting compound 17 which may contain irritating plasticizers and acid residues is isolated from the wearers ear. Also, where it is desirable to include the apparatus attachment bushing 15 as an integral portion of the outer sack 9, the resilience of the sack material facilitates insertion and captivation of the apparatus outlet despite the fact that the cured potting compound may be relatively rigid. Of course, any convenient apparatus fastening means may be used with the present invention, for example, by cementing to the sack. The compound 17 may be epoxy, polyester or acrylic resins, or the like, for a relatively rigid earmold casting. A less rigid, more flexible casting, frequently desirable because of the possible entrapment of the casting by certain outer ear shapes, may be produced using activatable silicone rubber compositions. The potting compound 17 selected should be one which has indefinite life in the inactivated state but which may be activated chemically or by external radiation or by other such convenient means to produce a compound that sets in shape within a few minutes. The chemical activator 21 for the compound 17 may be contained within a rupturable capsule 19 disposed within the sack 9.

The acoustic tube or channel 11 formed in the outer sack 9 eliminates the need for additional machine work conventionally required following completion of the earmold casting. This acoustic channel, as shown in FIG. 2, may be formed in the outer sack structure with a much thicker wall cross-section to prevent the channel 11 from collapsing when the outer sack 9 and activated compound 17 are pressed into the outer ear of the wearer during the casting process. The capsule or inner sack 19 disposed in the potting compound 17 within the outer sack 9 contains the compound activator 21 and is formed with easily fracturable walls. Thus, to activate the potting compound 17, the inner sack 19 may be squeezed or pinched through the outer sack 9 to burst the walls of the inner sack 19 and release the compound activator 21. The activator 21 may then be diffused through the compound 17 by kneading the outer sack 9 and a characteristic colorant in the activator 21 where the outer sack 9 is transparent or translucent will aid in indicating the uniform distribution of the activator 21 through the liquid compound 17. In order to facilitate the handling of the activated potting compound 17 and to insure proper support of the apparatus 23 within the outer ear of the wearer, the external apparatus 23 such as an earphone receiver or combination earphone-microphone transducer including an acoustic microphone tube 30 may be attached to the outer sack 9 by the bushing 15. The inner annular ridged flange 25 of the bushing 15 mates with the annular groove 27 around the outlet tube 29 of the apparatus 23" to hold the apparatus and sack 19 in close engagement during and after the curing of compound 17.

The outer sack 9 is positioned in the outer ear of the wearer before the activated compound 17 begins to set up, and with the tip 13 disposed in the wearers ear canal, a gentle pressure may be exerted on the outer sack 19 during the curing process, as by pressing against the apparatus 23, in order to assure conformation of the outer sack 19 to the shape of the wears outer ear with out unnecessarily distorting it. An outer sack 9 of general outer ear shape thus adapts to larger outer ears by shaping to the deeper recesses of the outer ear and ear canal and also adapts to smaller outer ears by setting up in more shallow position on the outer ear. After a few minutes of curing time, the compound 17 should be sufficiently set up to support the weight of the attached apparatus 23 without further manual support. The custom fitting of the earmold casting may thus be completed t 3 v 1 with onlya few minutes of the wearers time and without the need for additional machining, fitting or polishing. In another embodiment of the present invention, the outer sack 9 may be filled with thick plastic gel or clay-like compound which by pressure or kneading takes on the shape of the ear cavities suflicient to support the external apparatus '23.

FIG. 3 shows an earmold casting in position on the back and top side of the wearers outer ear. The outer sack 31 of biologically inert material is generally crestcentshaped to conform to the typical shape of the external region of an individuals outer ear and is filled with an activatable potting compound 34. This outer sack also includes a-'rupturable capsule 33 of activator ingredient 35 disposed within the sack 31 and may include an acoustic tube 37 which passes through the sack in a manner as described in connection with the embodiments of FIGS. 1 and 2. The acoustic tube 37 may extend either beyond the sack 31, as shown in FIG. 3, or may extend as part of the sack 31 over the upper forward portion of the outer ear to terminate in a resilient ear tip 39 disposed in the wearers ear canal. The crestcent-shaped sack 31 may thus extend over the top of the outer ear and extend around the back side of the ear down to the region adjacent the wearers ear lobe where it is desirable to provide adequate support for utilization apparatus 41. This apparatus 41 may include an earphone receiver 43, a microphone 45 and a connecting network 47 arranged in a miniature subassembly disposed to be supported on the earform casting. The upper end of this apparatus 41 may be attached to the earform casting previously activated and cast about the wearers ear as described in connection with the embodiments of FIGS. 1 and 2 simply by snapping the receiver outlet into a retaining bushing of the type described in FIG. 2 which is disposed in the earmold casting at the end of the acoustic tube or channel 37. The lower end of the apparatus 41 may also be detachably connected to the earmold casting in the region of the wearers ear lobe and may include a swivel joint 49 or other convenient attachment means for coupling an acoustic speaker tube 51 to the microphone 45. A connecting cable 53 may be attached to the apparatus 41 along a natural fall-line direction away from the apparatus 41, as shown in FIG. 3. Alternatively, the receiver and microphone, or each such unit alone in a miniature prepotted assembly, may be mounted directly inside the sack 31 with the receiver 41 acoustically coupled to the tube or channel 37 and with an acoustic microphone tube 51 protruding from the lower end of the crescent-shaped earmold casting adjacent the wearers ear lobe for coupling the sound emanating from the wearers mouth to the microphone 45.

What is claimed is:

1. Earform molding apparatus comprising:

a flexible outer sack substantially in'the shape of a selected region of the outer ear, the outer sack including an acoustic tube which passes through said outer sack from a tip portion thereof adapted to be positioned at the entrance to the ear canal of a wearer to a selected surface region of the outer sack adjacent a location thereon adapted to receive acoustic apparatus;

molding material within the outer sack which is capable 'of retaining the particular shape of the selected region of an outer ear about which it is molded;

means for attaching acoustic apparatus to said outer sack at said selected location thereon; and

acoustic apparatus attached to said outer sack at said selected location thereon and including an earphone receiver which is acoustically coupled to said acoustic tube at said selected surface region.

2. Earform molding apparatus as in claim 1 wherein:

said acoustic tube is an integral portion of the outer sack and includes walls defining said tube which are substantially thicker than the walls of said outer sack;

said means for attaching includes fastening means disposed about said selected surface region for attaching said earphone receiver to said outer sack at said selected surface region thereon in acoustically coupled relationship to said acoustic tube.

3. Earform molding apparatus comprising:

a flexible outer sack substantially in the shape of the external region behind the outer ear;

molding material within the outer sack which is capable of retaining the particular shape of the selected region of an outer ear about which it is molded;

means for attaching to said outer sack acoustic apparatus including an electrical-to-acoustical signal transducer and a first acoustic coupling tube attached at one end thereof to said electrical-to-acoustical signal transducer and disposed to pass over a portion of the top of the ear of a wearer with the other end thereof capable of being positioned at the entrance to the ear canal of the wearer;

a microphone transducer disposed on said outer sack near the lower end thereof in a region corresponding to the ear lobe of a wearer; and

a second acoustic coupling tube having one end attached to said microphone transducer and disposed to pass beneath the ear lobe of a wearer with the other end of said second acoustic coupling tube capable of being positioned adjacent a wearers mouth.

4. The method of forming an earform mold for supporting acoustic apparatus within the outer ear of a wearer comprising the steps of forming a flexible enclosure substantially in the shape of a selected region of the outer ear to be molded and including as an integral portion of the enclosure an elongated tube therethrough from a tip portion thereof adapted to be positioned atthe entrance to the ear canal of a wearer to a selected surface region of the enclosure remote from said tip portion; filling the enclosure with pliable molding material; and shaping the enclosure and molding material therein about the selected region of the outer ear of a wearer. 5. The method as in claim 4 comprising the additional steps, performed in selected sequence, of:

activating said pliable molding material to undergo substantial solidification; and attaching acoustic apparatus to said enclosure about said selected surface region thereof in acousticallycoupled relationship to the tube therethrough during the substantial solidification of said molding material.

References Cited UNITED Posen 179l07 RALPH D. BLAKESLEEpPrimary Examiner I US. Cl. X.R.

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