JP2019510278A - Temple bar and method of manufacturing temple bar - Google Patents

Abstract

A first end portion including a hinge member (11) suitable for connection to a hinge member (19) positioned on the spectacle frame portion (18), and further bent to form an ear pad (13); A temple bar including a suitable second end portion. The temple bar is made of a plastic material. In the channel (2) extending at least along the length of the second temple bar end portion, the metal rod (4) is fastened for reinforcement of the rod (1) of plastic material. In a position on the ear pad, an elastic resilient friction element (27) is connected to the temple bar to provide a contact contact with the back of the wearer's ear. The channel (2) is connected to a groove or notch (3) provided on the side of the plastic rod (1) that rotates inwardly in the ear pad (13). The metal rod (4) is releasable by a first lateral projection (5) adapted to be fastened in the plastic rod (1) and an opening (37) provided in the friction element (27). A second lateral projection (6) is provided that can provide a snap connection. [Selection] Figure 1

Description

  The present invention includes a first end portion including a hinge member suitable for connecting to a hinge member positioned on the spectacle frame portion, and a second end portion suitable for bending to form an ear pad. In relation to the spectacle temple bar comprising, the temple bar is made of a plastic material, and at least in a channel extending along the length of the second temple bar end portion, the metal rod is for reinforcement of the rod of plastic material. And in a position on the ear pad, an elastic resilient friction element is connected to the temple bar to provide a contact contact with the back of the wearer's ear.

  The present invention further includes a first rod end portion including a hinge member suitable for connection to a hinge member positioned on the spectacle frame portion, and a second end suitable for bending to form an ear pad. A temple bar comprising a portion, wherein the temple bar is made of a plastic material, and in at least a channel extending along the length of the second temple bar end portion, the metal rod is a plastic material. Fastened for reinforcement of the rod and in a position on the ear pad, an elastic resilient friction element is connected to the temple bar to provide a contact point with the back of the wearer's ear.

  That is, the temple bar is used in a pair of eyeglasses including an eyeglass frame portion, and two temple bars are connected to the eyeglass frame portion, and this connection is preferably pivotably connected to the eyeglass frame portion. Provided by each hinge member.

  For many years, it has been a known technique to produce acetate temple bars. The present invention is a result achieved based on the background of the problems faced by this. On the other hand, the present invention may find application to temple bars composed of other types of plastic materials, nevertheless, the following specification of the present invention is specifically described with reference to acetate. To explain.

  It is known to provide temple bars with friction elements that should be made interchangeable for the wearer in order to be most practical. This friction element is often present in the form of a tube that is drawn over the temple bar at a location located in the ear bend and serves to provide a contact contact behind the wearer's ear. This feature has typically been used in metal temple bars for the purpose of providing comfort to the wearer, but is also used in the case of temple bars made of plastic material. This avoids any direct contact between the plastic material and the sweat, fat, and other exhalations that may degrade the plastic. On the other hand, such tubes are believed to provide less comfort because the edges of the tube may be found to be uncomfortable for the wearer. Furthermore, the tube may slide along the temple bar, so there is a risk that it no longer maintains the optimum position on the ear pad.

  U.S. Pat. No. 6,045,221 proposes to position the friction element in an embedded manner in a recess positioned on the side of the first end portion of the temple bar with the intention of providing a connection with the spectacle frame portion. Has been. Plastics and especially acetate are very sensitive to notch fatigue effects, which requires that no sudden dimensional transitions are allowed within the provided shape of the temple bar, especially in the ear pads. . This introduces limitations towards the choice of the shape of the temple bar and on the reinforcing elements. That is, in US Pat. No. 6,045,221, the friction element to be used in the ear pad is shown to have the shape of a tube.

  Acetate is a soft plastic material and is therefore suitable for forming an ear-adapted bend by bending in a plane, i.e. positioned behind the wearer's ear and further adapted to the shape of the wearer's head Suitable for bending in another plane. Due to the softness of acetate, the temple bar had to reach a considerable size that previously gave difficulty in providing a bend, and additionally made a pair of glasses unnecessarily heavy, as well as in the ear. This resulted in the occupation of much space behind.

  It is desirable to minimize the size of the temple bar and improve comfort for the wearer in terms of both weight and size. However, this unfortunately results in a lack of both strength and shape stability. It is therefore also known to use rigid reinforcement elements in the form of longitudinal perforations in the temple bars or metal rods contained in the channels. This is due to the example described in US Pat. No. 1,369,953. This makes it possible to bend the plastic material to provide reinforcement of the rod of plastic material, thereby protecting the stable shape of the bending due to the properties of the metal rod and due to the simultaneous increase in strength. . Furthermore, such types of temple bars can be easily adapted by the optician or by the wearer without any risk of damaging the pair of glasses.

  In order to avoid the metal rod sliding out of the temple bar, it is held in place by gluing. However, we have experienced that the translational tension that appears during the bending process while bending the rod of plastic material to reach the wearer's adaptation may be able to sufficiently overcome the holding force obtained from adhesive joints. Shows. Therefore, there is a need for another way of fixing that protects the metal rod from staying in a fixed connection position relative to the plastic rod.

  Furthermore, from US Pat. No. 4,563,066, a temple bar made of a metal rod is known. At the end portion at the ear pad, the metal rod is covered by a bushing of plastic material fastened on the metal rod. Within this area, the metal rod is provided with a serrated projection that protects the surrounding plastic sheath from staying fastened on the metal rod as well as bonding. The surrounding plastic sheath is contained within the drip-shaped end portion of the surrounding silicone rubber sheath that is fastened on the metal rod in the ear pad. The possibility of replacing the composite plastic material silicone rubber surrounding the sheath is not provided.

  Thus, in connection with the plastic material temple bar, it provides a simple manner of integration as a reinforcing element and as a friction element in the rod of plastic material, i.e. the optician or wearer himself makes the temple bar There is a need to be able to adapt to the shape, so that the wearer can replace the friction element in an easy and simple manner.

US Pat. No. 6,042,221 US 1736953 US Pat. No. 4,563,066

  The present invention avoids the problems associated with the temple bars belonging to the prior art and thus makes it possible to integrate the friction element and the reinforcing element in a simple manner within the plastic rod, which is also a spectacle technician or wearer. Which can easily provide the adaptation of the shape of the temple bar, as well as the exchange of the friction elements in an easy and simple manner, and a method for manufacturing such a temple bar It contributes to the purpose of introducing.

  This is achieved according to the invention with a temple bar of the type mentioned in the introduction, and the channel is connected to a groove or notch provided on the side of a plastic rod that rotates inwardly within the ear pad, and The metal rod is provided with a first lateral projection and a second lateral projection adapted to be fastened in a plastic rod that can provide a releasable snap connection with an opening provided in the friction element. It is peculiar.

The method according to the invention comprises:
a-Manufacture of plastic rods showing the basic shape of temple bars;
b-manufacture of channels in plastic rods,
c-production of a transverse groove or notch in a plastic rod extending from one side edge and staying in connection with the channel;
manufacture of a metal rod comprising a first lateral projection and a second lateral projection on opposite side edges of the central portion of the metal rod between the end portions which are longer than the length of the d-notch and are not provided with a projection;
placing the metal rod in the e-notch and thereby bending the plastic rod and metal rod, possibly in the presence of an internal channel, leaving the end portion of the metal rod inserted into the channel;
f-fastening the first lateral projection in the plastic rod while simultaneously applying pressure to establish a secure grip between the first lateral projection and the plastic rod;
g--production of an elastic resilient friction element comprising an opening capable of cooperating with a second lateral projection,
placing the friction element in the h-notch, whereby the second lateral projection is press fit into the opening of the friction element to provide an elastically releasable snap connection;
characterized by including the step of bending the i-Temple Bar to provide an ear pad.

  That is, the present invention makes it possible to solve the problems associated with the prior art in which the reinforcing element is fastened to the plastic rod by bonding. The experience gained is that the bond was insufficient as a force acting during bending of the temple bar causing the bond to break.

  Furthermore, according to the invention, reinforcement of the plastic rod is provided in that the reinforcing element in the form of a metal rod is brought to extend on either side of the notch and into a channel established in the metal rod. . This avoids the risk of breakage due to notch fatigue in the notch.

  In that the metal rod is provided with lateral projections, a secure fastening in the plastic rod is achieved when the fastening is preferably established by welding. Preferably, the welding is ultrasonic welding during which pressure is applied so that the lateral projections are inserted into the plastic rod and fastened there.

  In this manner, the wearer can easily replace the friction element because the metal rod includes a second lateral projection that can provide a releasable snap grip with the friction element at the ear pad. Because the friction element is placed in place within the notch in the plastic rod, there will be no sharp edges that can be uncomfortable for the wearer.

  Since plastic rods are reinforced by metal rods that are completely or only partially contained, it is therefore possible to use small dimensions, whereby the temple bar is in the form of a large volume feature, It will not exist in the ear.

  According to yet another embodiment, the temple bar according to the present invention is characterized in that the protrusion at the connection with the metal rod has a smaller cross section than the cross section of the protrusion at a constant distance from the metal rod.

  Both the first and second lateral projections can exhibit the same shape, or they can exhibit different shapes. On the other hand, it is preferable that they show a cross-sectional shape drawn as an example showing the shape of a mushroom or an arrow. Thereby, the insertion into the plastic material will provide a safe grip and a safer in-situ hold by the first lateral projection. The second lateral projections can easily establish a snap grip function when they are present showing a mushroom shape or an arrow shape.

  According to yet another embodiment, the temple bar according to the present invention is provided as an elastic elastic element in which the friction element includes a lateral opening for occupying the second lateral projection due to the elastic elasticity of the friction element material. It is characterized by that.

  In order to achieve a particularly easy snapping function, the friction element is preferably made of an elastic resilient material. Thereby, the wearer can establish the snap grip function in a particularly easy manner. At the same time, the elastic resiliency of the friction element material will cooperate for safe in-situ retention of the friction element. Furthermore, elastic resilience makes it easier for the wearer to provide a snap grip compared to a friction element that provides a hard material.

  According to yet another embodiment of the present invention, the temple bar is characterized in that the first lateral projection is fastened to the plastic rod and contained therein by welding.

  As described above, welding provides a preferred embodiment for embedding the first lateral projection in the rod of plastic material. By providing for embedding during welding, softly made plastic materials are brought to surround the lateral projections in a safe manner while they are simultaneously pressed into the plastic material.

  According to yet another embodiment according to the present invention, the temple bar has the shape of the inner channel on either side of the notch so that the end of the metal rod does not include protrusions and the metal rod is longer than the length of the notch. Extending into the channel.

  In order to protect the easily implemented mounting, the end portion of the metal rod on either side of the first and second protrusions should be shown to be a smooth rod or plate-like. . In this way, it is facilitated in a simple manner that allows these end portions to extend into the channel on either side of the protrusion. Thereby, efficient reinforcement of the plastic material is achieved to the extent that the notch is provided. In this way, the risk of the plastic material breaking is avoided when the ear pads are made. Thus, the earpiece can be provided in a safe manner by the optician or by the wearer.

  It should be noted that the reinforced metal rod not only protects against breakage of the plastic material in the bend. It further provides stability to the shape of the temple bar. This stability of the shape is not only provided in the plane of the ear pad, but is also bent in a direction that extends perpendicular to that of the ear pad to provide adaptation to the shape of the wearer's head Sometimes further establishes the stability of the shape.

  According to yet another embodiment according to the invention, the temple bar is characterized in that the plastic rod is made of acetate.

  Acetate is a preferred material. On the other hand, other plastic materials can be selected when the temple bar is manufactured.

  According to a further embodiment according to the invention, the temple bar is characterized in that the metal rod is made of titanium.

  Titanium is preferred for the production of metal rods because this material exhibits a very low weight. On the other hand, other metals can also be used when manufacturing metal rods.

  According to yet another embodiment according to the invention, the temple bar is characterized in that the plastic rod exhibits a rectangular cross section and the first and second lateral projections are molded on two opposite sides of the metal rod.

  Although the metal rod can be manufactured with a circular or oval cross section, it is preferred that the rod has a rectangular cross section. More preferably, the plastic rod exhibits a rectangular cross section. Using this shape, the first and second protrusions on the metal rod are provided on two narrow opposing sides of the metal rod. These protrusions can be provided by molding or cutting a metal rod from a metal sheet.

  When the rectangular metal rod is placed and embedded in the plastic rod, the second protrusion will be positioned at the opening of the notch in the rectangular cross section of the plastic rod. This is protected by positioning the metal rod within the central notch in the plastic rod.

  According to a further embodiment according to the invention, the temple bar corresponds to that of the notch such that the friction element corresponds to the cross section of the temple bar on the area on either side of the notch with the cross section of the temple bar just outside the notch. It is characterized by showing the external shape.

  When the friction element obtains an external shape corresponding to the size of the notch, there will be no sharp transition. The friction element will be positioned in the notch so that the cross section of the temple bar in the area on either side of the notch will correspond to the cross section just outside the friction element. It can be expressed in such a way that the friction element is countersunk and positioned in the temple bar and the outer surface forms a common plane with the outer surface of the plastic rod.

  According to yet another embodiment according to the present invention, the temple bar exhibits a lateral opening in which the channel of the plastic rod extends from the notch to the second end portion of the temple bar, whereby a portion of the metal rod is removed from the lateral opening of the channel. It is characterized by protruding.

  The channel of the plastic rod can be a closed channel, or it can be an internal channel simply provided with an opening at the end of the channel, or perhaps the channel is manufactured as a channel with a lateral opening. In that case, the channel can be characterized as an open channel. When this channel extends from the end of the second temple bar end portion to the notch, it is possible to place the metal rod in place by being inserted through a lateral opening. In such an embodiment, it is preferred that the metal rod includes an outermost end portion that will be placed in place in the closed channel at the second temple bar end portion in a direction pointing away from the spectacle frame portion.

  With this structure, the metal rod can simultaneously form an integral part of the hinge member used for fastening the temple bar to the spectacle frame portion. If a closed internal channel is used in which the metal element does not extend along the entire length of the plastic rod, a further metal rod must be used. This needs to be fastened to the acetate and at the same time a hinge member that can cooperate with the hinge member on the spectacle frame part needs to be provided. By using a channel that includes a lateral opening along most of its length, it is possible to provide plastic rod reinforcement while at the same time achieving easier attachment of the hinge portion.

  According to a further embodiment according to the invention, the temple bar is characterized in that a plastic rod within the range between the notch and the lateral opening covers the side of the metal rod.

  In order to protect the presence of a smooth surface at the ear pads, the plastic rod preferably comprises material on either side of the notch. Even when a channel containing a lateral opening is used, it is preferred that there be a material that exhibits an extension such that the cross-section of the plastic rod on either side of the notch is equal, at least in the area aligned with the notch. This allows the friction element to be positioned between items of plastic material. If the plastic rod does not contain material covering the side of the metal rod protruding from the lateral opening of the channel, the friction element will be placed in a notch that only includes a termination at one end of the friction element. Such an embodiment is also possible.

  The invention is further specified below with reference to the drawings.

FIG. 4 shows the various stages belonging to the method used in the manufacture of temple bars according to the invention. 1 is a side view of a first embodiment of a temple bar including an internal channel. FIG. FIG. 4 is a set of glasses according to another embodiment of a temple bar according to the present invention, part of the figure including an open channel. FIG. 4 is a detailed view of the temple bar according to FIG. 3. FIG. 5 shows some single elements forming part of the type of structure used in the temple bar according to FIGS. 3 and 4. FIG. 3 shows a temple bar according to the invention waiting for wearing in a pair of glasses after being bent. It is a figure which shows different embodiment of a 1st and 2nd sideways protrusion as an example.

  In FIG. 1, single stages AK show the method used in the manufacture of temple bars.

  According to stage A, an acetate plastic rod 1 comprising a channel 2 and a transverse notch 3 is provided.

  According to stage B, the reinforcing metal rod 4 is shown. The metal rod 4 includes a first lateral projection 5 and a second lateral projection 6 positioned on opposite sides with respect to the first lateral projection.

  By stage C, the metal rod 4 is shown to be placed on the plastic rod with first and second lateral projections positioned outward from the notch 3. The metal rod represents a smooth surface area that can be received in the channel 2 in each side section 7 of the section 8 with the lateral projections 5, 6.

  According to stage D, the side section 7 of the metal element (not shown in stage D) is arranged in the channel 2 and the metal rod 4 is shown to exhibit an ambiguously curved shape.

  By stage E, the welding body 9 is pressed against the metal rod, thus fastening it to the plastic rod 1 by welding and positioning it while maintaining its shape within the plastic rod 1.

  According to stage F, a finished shape is shown in which the metal rod 4 is included so as to fit within the plastic rod 1.

  According to stage G, a method is shown in which the open accessible second projection 6 is thus freely accessible at the side edge of the plastic rod.

  According to stage H, the friction element 27 is shown being pressed into the notch 3. The friction element 27 includes a series of openings 37 in which the second protrusion 6 is received by a releasable snap grip.

  Stage I shows the finished temple bar including a straight shape. The metal element 10 is shown mounted on the plastic rod 1. The metal element 10 is provided with a hinge member 11 that can cooperate with a hinge member on the spectacle frame portion.

  Stage J shows that a bending operation 12 is performed to provide an ear pad 13. A friction element 27 is provided on the inner side of the ear pad in the notch 3.

  Step K shows how the plastic rod 1 reaches a curved shape which further adapts itself to the shape of the wearer's head. In the final shape, as shown in FIG. 1, the temple bar is waiting to be attached to the spectacle frame portion.

  In FIG. 2, a metal rod composed of two parts, a first part 13 and a second part 14 is shown. The first part 13 is shaped as described above with reference to FIG. The two parts 13 and 14 are adapted to be positioned in the plastic rod 1 as shown below in FIG. In this connection, see that the second part 14 of the metal rod includes an extension on the outside of the plastic rod 1 that can provide the hinge member 11 or occupy a position outside the plastic rod. Can do.

  The second part 14 is provided with a transition channel in the plastic rod which can be occupied as a longitudinal element-shaped part 15 and further a rolling slot which can occupy the plate-like part of the second part 14. In that respect, it can be brought to a predetermined position in the plastic rod 1.

  FIG. 3 shows a pair of eyeglass halves 17. Half set 17 includes a spectacle half frame 18 which is shown to include a hinge member 19 cooperating with hinge member 11 positioned on plastic rod 1. The half frame 18 includes a lens 20 and a nasal bridge support pad 21 as in the prior art.

  According to FIG. 4, the ear pad 13 is shown on an enlarged scale. Thereby, it is shown how the friction element 27 is arranged in the notch 3 so that both the face of the friction element and the face of the plastic rod 1 share a common plane configuration. Thereby, along the longitudinal length, the temple bars are brought to show an unchanged cross-sectional shape.

  FIG. 5 shows three items forming the part of the temple bar shown in FIGS. 3 and 4. The items shown are a plastic rod 1, a metal rod 4, and a friction element 27.

  3 to 5, the channel 2 is shown open, so that the transition metal rod 4 protrudes from the plastic rod through the lateral opening 22 belonging to the channel 2.

  FIG. 6 shows an area 23 in which the plastic item protrudes by the notch 3. Thereby, at both ends of the notch, respective protruding portions of plastic are provided, and the friction element 27 is arranged between them.

  According to the embodiment shown in FIGS. 3 to 5, the metal rod is shown protruding from the plastic item along the entire length of the rod, and at the frame end of the metal rod 4, this rod is connected to the hinge member 11. It is embodied to be able to. As an alternative embodiment, the hinge member 11 can be provided so as to be integrated with the metal rod 4 by being shaped by a sharp bend of the metal rod 4.

  In FIG. 6, the temple bar is shown molded according to the principle illustrated and illustrated in FIGS. According to this embodiment, the metal rod 4 projects from the lateral opening of the channel in the plastic rod 1.

  FIG. 6 shows how it is possible not only to mold the plastic material in three dimensions, ie to provide an ear pad 13 that is geometrically configured in a plane. Accordingly, as illustrated and illustrated on the leftmost side of FIG. 6, a curved shape 24 is provided to achieve adaptation to the wearer's head. In the lowermost part of FIG. 6, a method of providing an S-shaped bend 25 in the ear pad is shown. The resulting three-dimensional shape that can provide the temple bar will remain and provide without any risk of breaking the plastic rod 1 due to the rolling slot notch effect at the notch 3 in the bending process. be able to.

  FIG. 7 shows a different embodiment of the first lateral projection 5 and the second lateral projection 6 in the section 8 of the metal rod. The protrusions 5 and 6 can be shaped as in linear extension protrusions that exhibit the same cross-sectional shape in their full extension from the central portion 26 of the metal rod 4, but the mushroom shape or arrow shape is They are preferred as shown at the top of the, or they can obtain a configuration comprising an edge or a circular configuration as shown at the bottom of the figure. The embodiments of the protrusions 5 and 6 have in common that they show a smaller cross-section connected to the central part 26 of the metal rod than those where they are farther from the central part 26. Thereby, a particularly safe embedding of the first protrusion 5 in the plastic material is obtained.

  Due to their shape, the second lateral projections 6 can be slid into these openings and kept in place by a snap grip, so that the friction element 27 is particularly safe with the opening 37. A grip will be established. The snap grip is further amplified when the friction element is made of an elastic resilient material as an example of rubber.

  The dimensions for practical applications for plastic rods and metal rods exhibiting a rectangular shape can be mentioned as an example. The thickness of such a plastic rod will typically be 2-5 mm and the height will typically be 3-7 mm. The thickness of the metal rod to be included in the plastic rod will be 0.5-1.5 mm. The height of the protrusion is typically 0.7-2 mm.

1 Plastic rod 3 Notch 4 Metal rod 5 and 6 Protrusion 27 Friction element

Claims (12)

A first rod end portion including a hinge member (11) suitable for connection to a hinge member (19) positioned on the spectacle frame portion (18), and further bent to form an ear pad (13). A temple bar comprising a second end portion suitable for the channel, wherein the temple bar is made of a plastic material and extends at least along the length of the second temple bar end portion. A metal rod (4) is fastened to reinforce the plastic material rod (1), and at a position on the ear pad, an elastic resilient friction element (27) is in contact with the back of the wearer's ear. The temple bar connected to the temple bar to provide a contact, comprising:
The channel (2) is connected to a groove or notch (3) provided on the side of the plastic rod (1) that rotates inwardly in the ear pad (13),
The metal rod (4) is provided with a first lateral projection (5) adapted to be fastened in the plastic rod (1) and an opening (37) provided in the friction element (27). A second lateral projection (6) that can provide a releasable snap connection with
A temple bar characterized by that.   2. The temple according to claim 1, wherein the protrusions (5, 6) exhibit a cross section smaller than a cross section of the protrusion at a certain distance from the metal rod at a connection portion with the metal rod. bar.   The friction element (27) is provided as an elastic elastic element including a lateral opening (37) for occupying the second lateral projection (6) due to the elastic elasticity of the friction element material. The temple bar according to claim 1 or 2.   4. The temple bar according to claim 1, wherein the first lateral projection (5) is fastened in the plastic rod (1) and contained therein by welding. 5. . The end portion of the metal rod does not include a protrusion,
The metal rod (4) is longer than the length of the notch (3), whereby the end portion extends into the channel (2) in the form of an inner channel on either side of the notch,
The temple bar according to any one of claims 1 to 4, wherein:   Temple bar according to any one of the preceding claims, characterized in that the plastic rod (1) is made of acetate.   Temple bar according to any one of claims 1 to 6, characterized in that the metal rod (4) is made of titanium. The plastic rod (1) shows a rectangular cross section,
The first and second lateral projections (5, 6) are formed on two opposing sides of the metal rod;
The temple bar according to any one of claims 1 to 7, characterized in that:   The friction element (27) is in the notch (3) so that the section of the temple bar just outside the notch (3) corresponds to the section of the temple bar in the area on either side of the notch. The temple bar according to claim 1, wherein the temple bar exhibits a corresponding external shape.   The channel (2) of the plastic rod shows a lateral opening (22) extending from the notch to the second end portion of the temple bar, whereby a portion of the metal rod protrudes from the lateral opening of the channel The temple bar according to any one of claims 1 to 9, wherein:   11. The plastic rod in a range (23) between the notch (3) and the lateral opening (22) covers a side surface of the metal rod. Temple bar. A first rod end portion including a hinge member (11) suitable for connection to a hinge member (19) positioned on the spectacle frame portion (18), and further bent to form an ear pad (13). A temple bar comprising a second end portion suitable for the channel, wherein the temple bar is made of a plastic material and extends at least along the length of the second temple bar end portion. A metal rod (4) is fastened to reinforce the rod (1) of plastic material, and at a position on the ear pad (13), an elastic resilient friction element (27) is placed on the back of the wearer's ear. A method of manufacturing the temple bar connected to the temple bar to provide a contact point with
a stage of production of a plastic rod (1) showing the basic shape of the a temple bar;
b-the stage of manufacture of the channel (2) in the plastic rod;
c--a step of manufacturing a transverse groove or notch (3) in the plastic rod extending from one side edge and staying connected to the channel;
d- a first lateral projection (5) and a second projection on opposite side edges of the central portion (8) of the metal rod between the end portions (7) which are longer than the length of the notch and are not provided with projections; Stages of manufacturing a metal rod (4) comprising two lateral projections (6);
e-placing the metal rod (4) in the notch (3), thereby possibly bending the plastic rod and the metal rod in the presence of an internal channel so that the end portion of the metal rod becomes the channel ( 2) to be inserted into the state;
f--fastening the first lateral projection (5) into the plastic rod and simultaneously applying pressure to establish a safe grip between the first lateral projection and the plastic rod;
g—the stage of manufacture of an elastic resilient friction element (27) comprising an opening (37) capable of cooperating with said second lateral projection (6);
h-placing the friction element (27) in the notch (3), whereby the second lateral projection (6) is press-fit into the opening (37) of the friction element and can be released elastically Providing a snap connection; and
i—bending the temple bar to provide an ear pad (13);
A method comprising the steps of:

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