AN EAR PROTECTOR

Abstract: The invention relates to an ear protector (1) of the kind which comprises two earmuffs (2, 3) which cover the respective ears of the person wearing the ear protector, and a headstrap (6) or like device which mutually connects the earmuffs and earmuff frames. Respective earmuff frames (2', 3') have an outer convex surface and are preferably provided with means for holding a ring (8) which surrounds a respective ear, and a telephone receiver (10) is enclosed in at least one earmuff (3) for reproducing information received (14) via IR-radiation. The earmuff frame is made of a plastic material which is at least transparent to IR-radiation, and one or more IR-radiation receiving diodes (14) is/are mounted on or adjacent to the inner surface (3c) of the earmuff and the earmuff frame.

Description: TITLE OF THE INVENTION: AN EAR PROTECTOR TECHNICAL FIELD The present invention relates generally to an ear protector, or hearing guard, and then particularly to an ear protector of the kind which comprises two ear- muffs which cover respective ears of the wearer, and normally an earmuff-supporting headband or helmet, and in which the earmuffs are provided with an external curved surface and an opening, and in which the ear- muffs are preferably provided in the region of said opening with a device by means of which a ring which surrounds the ear can be held against the head of the wearer. The invention relates more particularly to such ear protectors as that in which a telephone receiver is connected to at least one earmuff, which enables infor¬ mation received via modulated infrared radiation to be reproduced via electronic circuits. BACKGROUND ART Ear protectors of the aforesaid kind augmented with a telephone receiver are known to the art and are used normally when performing work in noisy environments in which the noise levels exceed 85dB(A) and where there is a need for the workmen present to communicate with one another through speech signals. It is also known that in order to converse in such noisy environments, it is necessary for such ear pro- tectors to function as telephone devices, i.e. the protectors must be provided with a microphone and telephone receiver, the latter in the form of a receiv¬ ing capsule. It is also known to install in the earmuff of the ear protector a plate onto which the telephone receiver can be secured and to enclose the plate and the telephone receiver in a pourous sound damping material. Also known to the art are several different cordless or wireless information transmission systems adapted for use with modulated photodiodes, so-called IR-light or IR-beams, where light is transmitted by special IR- photodiodes and is received by special diodes, so- called PIN-diodes. An example of the earlier known art is found in eguip- ment intended for single-path remote control of televi¬ sion sets and video tape recorders. Other single-path applications have also been proposed in the art. Particularly significant to the present invention is a two-path information transmission system in which modulated IR-light or IR-beams are used for speech communication between people present in a restricted space or between a person present within a restricted space and a person present outside said space. This enables fully acceptable speech communication to be carried out between persons who are in close proxi¬ mity of one another in a noisy environment and between these persons and persons located outside said noisy environment. A system which affords the possibility of such com¬ munication is described in more detail in the U.S. Patent Specification No. 4,648,131, in which the requisite photodiodes are mounted on a helmet. Swedish Patent Application No. 8903572-9, filed on the 26th October, 1989., illustrates and describes a two.- path cordless information transmission system in which IR-beam generating diodes and IR-beam receiving diodes, so-called PIN-diodes, are mounted on the earmuffs of the ear protector. Finally, it can be mentioned that it is known that certain plastic materials tend to exhibit good trans- parent properties for IR-light but have the tendency of strongly damping permeability for light of other wavelengths. DISCLOSURE OF THE PRESENT INVENTION TECHNICAL PROBLEMS When considering the earlier state of the art, as described above, it will be seen that a technical problem resides in the provision of means which render it no longer necessary to mount separate photodiodes on an earmuff or earmuffs of an ear protector, and subse¬ quent to forming a hole in the earmuff or earmuffs, to enable these diodes to be connected to electronic circuits mounted within the earmuff or earmuffs, while still presenting a simple construction. It will also be seen that a further technical problem resides in positioning the requisite light-transmitting and light-receiving diodes intended for speech communication with an ear protector in a manner such as to eliminate the use of a separate guard, on either the earmuffs or the helmet as protection against mechanical damage from an external source. In this respect, a qualified technical problem is one of realizing that the aforesaid technical problems pan be solved by placing all diodes within respective earmuffs and by positioning or otherwise arranging said diodes within said earmuffs or earmuff in a manner such that the light-transmitting diodes are able to transmit IR-light without being affected by the light-receiving diodes which receive IR-light. Another technical problem is one of configuring the earmuff or earmuffs in a particular manner and produc¬ ing said earmuff or earmuffs from a particular material such as to enable the diodes to be mounted within the earmuff/earmuffs of the ear protector, said material not only being transparent to infrared light but also capable of being moulded. It will also be seen that a further technical problem resides in the selection of a plastic material which has properties that will enable the earmuffs to be extrusion-moulded and/or cast in moulds, and which also exhibits a colour and/or other properties which render respective earmuffs transparent to infrared light, with only small losses. It will also be seen that a further technical problem resides in the provision of conditions, with the aid of simple means, such that one or more diodes that are intended to receive modulated IR-beams can be mounted at a small distance from or towards the inner surface of a respective earmuff, without the damping engendered by the material from which the earmuff is made and the colour selected reaching unacceptable values. It will also be seen that a further technical problem is one of selecting from all available plastic mate¬ rials a plastic material which is suitable for said, purpose and to realize that the plastic material selec¬ ted shall have properties equal to or at least substan- tially corresponding to the properties of the plastic material known as "IR-MAKROLON". Another technical problem is one of realizing the importance of mounting one or more IR-light transmit- ting diodes adjacent the inner, concave surface of the earmuff. It will also be seen from the known prior art described above that a technical problem resides in realizing the importance of mounting the requisite diodes and requi¬ site electronic circuits and telephone receiver on a printed circuit board and also to realize the advant¬ ages that are afforded when the IR-light transmitting diodes are mounted on the actual circuit board itself while the IR-receiving diodes are mounted close to the inner surface of the earmuff and in spaced relationship with the transmitting diodes. It will also be seen that a technical problem resides in enabling the earmuffs to be produced in the same injection moulding tools or casting tools as those earlier used to produce conventional earmuffs, despite the addition of diodes and electronic circuits to said earmuffs, and thereby save tool costs. SOLUTION The present invention provides a solution to one or more of the aforesaid technical problems and is based on an ear protector of the kind which includes two earmuffs which carry the ear protector and which cover the ears of the wearer, and which normally further . include a headband or the like connecting said ear- muffs, wherein the earmuffs have an outer, convex surface and are preferably provided with means for holding a ring which lies against the head and sur¬ rounds the ear.of the wearer, and in which a telephone receiver is enclosed in at least one of said earmuffs for the purpose of reproducing information received via modulated IR-beams. It is proposed in accordance with the invention that the earmuff of an ear protector of this kind shall consist of a plastic material which is transparent to at least IR-beams and that one or more IR-beam receiv¬ ing diodes is or are mounted on or adjacent the inner surface of the earmuff. It is proposed in accordance with further embodiments which lie within the scope of the inventive concept tfiat the earmuff is made of an extrudable and/or mould- able plastic material having properties equal to or at least corresponding to the properties of "IR-MAKROLON". It is also proposed that one or more IR-beam transmit¬ ting diodes is/are mounted adjacent the inner concave surface of the earmuff. According to one embodiment, the IR-beam receiving diodes are connected electrically to a printed circuit board, whereas the IR-beam transmitting diodes are mounted close to said board or on said board. It is also proposed that the telephone receiver is fixedly mounted in the centre of said circuit board. Finally, it is suggested that the circuit board is . positioned adjacent to but spaced from the open part of the earmuff facing towards the surrounding ring. ADVANTAGES The advantages primarily afforded by an inventive ear protector lie in the possibility of achieving the transmission of information, particularly the transmis¬ sion of speech signals, with the aid of modulated IR- beams, by using a circuit board on which or to which transmitting and receiving diodes are mounted or con¬ nected, and which is placed within the earmuff. By producing the earmuff from a plastic material which is pervious to IR-beams, there is provided an ear protec¬ tor which requires the provision of no additional devices on the external surfaces of the earmuff of said protector or in a recess formed therein to this end, while the requisite diodes are well protected against mechanical damage. The primary characteristic features of an inventive ear protector are set forth in the characterizing clause of the following Claim 1. BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of an inventive ear protector at present preferred will now be described in more detail with reference to the accompanying drawings, in which Figure 1 is a perspective view, partly in section,, of an ear protector having two earmuffs, each of which has enclosed therein a respective printed circuit board having mounted thereon a number of IR-beam transmitting diodes and a number of IR-beam receiving diodes; Figure 2 is a top view illustrating the principle of a printed circuit board significant to the invention; and Figure 3 is a sectional view of a receiving telephone according to Figure 1. DESCRIPTION OF EMBODIMENTS AT PRESENT PREFERRED Figure 1 illustrates in perspective an ear protector 1 comprising two sound-attenuating earmuffs 2, 3 and a headstrap 6 carrying the earmuffs. Parts of the earmuffs have been removed, for the sake of illustration. The earmuffs 2 and 3 are principly identical to one another, with the exception that a microphone bar 4 with associated microphone 5 is mounted on the the frame or body 3'of one earmuff, and that the necessary electrical connection passes through the earmuff to a circuit enclosed therein. Each earmuff 2, 3 has formed therein an opening which is dimensioned to extend over a respective ear of the person wearing the ear protector. The earmuffs 2, 3 are carried by an extensible head- strap 6, to which respective earmuff frames or bodies 2' and 3' are pivotally connected. Each earmuff 2, 3 and earmuff frame 2', 3' has an outer, convex surface 2a, 3a and, in the case of the illustrated embodiment, is provided with means 2b, 3b (not shown in detail) which hold a ring 7, 8 which is intended to surround a respective ear and lie against the head of the wearer. Each earmuff 2 and 3 has enclosed therein a telephone receiver 9 and 10. At least one of the earmuffs is equipped with one such telephone receiver, so as to enable information signals received in the form of modulated infrared radiation, or IR-beams, to be repro¬ duced with the aid of said receiver telephone and the requisite electronic circuits. The circuitry and the conditions required for trans¬ mitting and receiving information with the aid of IR- beams is known to the art. There is nothing to prevent the recommendations il- lustrated and described in the aforesaid Swedish patent application from being used with the illustrated em¬ bodiment, and hence these components and the manner in which the system works will not be described in detail here. For the sake of illustration, certain parts of the earmuff illustrated in Figure 1 have been removed so as to show the positioning of the circuit board 12, 13 used. According to the present invention, the earmuff frame 2', 3' is made from a plastic material which is trans¬ parent to IR-radiation, and one or more IR-radiation receiving PIN-diodes 14 are mounted in spaced relation- ship with the circuit board, on the inner surface 2c, 3c of the earmuff and the earmuff frame. The earmuff frame will preferably be made of an ex¬ trudable and/or mouldable plastic whose properties are equal to, or at least substantially comparable with the properties of the plastic material retailed under the trademark IR-MAKROLON. One or more IR-light transmitting diodes 11 is/are mounted on or adjacent to the printed circuit board 13. The diodes 14 intended for receiving IR-beams are connected electrically to the circuit board 12 in the earmuff 2 and to the circuit board 13 in the earmuff 3, whereas the diodes 11 intended for transmitting IR- beams are fixedly or permanently mounted on said cir¬ cuit boards. The respective telephone receivers 9 and 10 are held by said circuit boards 12 and 13 in a known manner, and respective circuit boards are positioned centrally adjacent (at an adapted distance from) the apertured part of the earmuff which faces towards the surrounding ring 7 or 8. Figure 2 is a top view of a printed circuit board 12. The requisite electronic components are only shown schematically, although it shall be noted that the telephone receiver 9 is accommodated in a centrally positioned aperture 12a. » A number of IR-beam transmitting diodes are fixedly connected to the circuit board by means of respective connections 12b-12g. These connections are thus made directly to the circuit board. Connected in parallel with the connection I2h are a number of IR-beam receiving diodes 14, so-called PIN- diodes. These diodes are placed side-by-side on a holder strip and are intended to lie close to the inner surface of a respective earmuff, preferably with the arrangement of a sound-insulating layer between the PIN-diodes and the circuit board 13. Figure 3 is a sectional view of the earmuff 3. Figure 3 illustrates the ring 8, a sound-damping foam-rubber layer or like layer 3d, whose circuit board 13 with the necessary components and the six IR-beam transmitting diodes 11, a sound-attenuating, foam-rubber layer or like layer 3e and a strip 3f on which the requisite PIN-diodes 14 are mounted in side-by-side relationship. It will be understood that the invention is not res- tricted to the described and illustrated exemplifying embodiment thereof and that modifications can be made within the scope of the invention as defined in the following Claims. It is to be noted that the material sold under the Trade Mark MAKROLON, by Bayer AG, Leverkusen, Germany, shall preferably have the colour 45/401. The expression IR-MACROLON is used to indicate that the material is transparent for IR radiation.

Claims: CLAIMS 1. An ear protector comprising two earmuffs which cover the ears of the person wearing the protector, a headstrap or the like which mutually connect the ear- muffs and the earmuff frame, wherein respective.earmuff frames have an outer convex feurface and are preferably provided with means for securing a ring which encircles a respective ear of the wearer, and further comprising a telephone receiver enclosed in at least one earmuff and operative to reproduce information received via IR- beams, c h a r a c t e r i z e d in that the earmuff frame comprises a plastic material which is transparent at least to IR-radiation; and in that one or more IR- radiation receiving diodes is/are mounted on or ad¬ jacent the inner surface of the earmuff and earmuff frame. 2. An ear protector according to Claim 1, c h a r a c t e r i z e d in that the earmuff frame is made of an extrudable and/or mouldable plastic material whose properties are equal to or at least correspond to the properties of the material "IR-MAKROLON". 3. An ear protector according to Claim 1 or 2, c h a r a c t e r i z e d in that one or more IR- radiation transmitting diodes is/are mounted adjacent the inner, concave surface of the earmuff or earmuff frame. 4. An ear protector according to Claim 1, 2 or 3, c h a r a c t e r i z e d in that the IR-radiation receiv¬ ing diodes are mounted on a printed circuit card, whereas the IR-radiation transmitting diodes are moun- ted or close to said circuit card. 5. An ear protector according to Claim 1 or 4, c h a r a c t e r i z e d in that the telephone re¬ ceiver is mounted centrally and held firmly by said circuit board. 6. An ear protector according to Claimn 1, 4 or 5,. c h a r a c t e r i z e d in that the circuit board is placed adjacent to and at a distance from that part of the earmuff which faces towards the surrounding ring.

Inventors: ROSEN GOESTA, ROSEN, GOESTA
Applicants: ROSEN GOESTA, ROSEN, GOESTA
Application year: 1991
Main classification: H04R1
IPC codes: A61F11, H04B10, H04M1, H04R1