Temple bar and a method of manufacturing a temple bar
The scope of the invention
The present invention relates to an eyeglass temple bar comprising a first end portion, which comprises a hinge member suited to be connected to a hinge member located on an eyeglass frame portion, and further a second end portion suited to be bend forming an earpiece, which temple bar is made of a plastic material and where within a channel, which is extending at least along the length of the second temple bar end portion, a metal rod is fastened for the reinforcement of the rod of plastic material, and where at a positon on the earpiece an elastic resilient friction element is connected to the temple bar to provide a contact of touch with the back of a wearer's ear.
Furthermore, the present invention relates to a method for manufacturing a temple bar comprising a first rod end portion, which comprises a hinge member suited to be con- nected to a hinge member located on an eyeglass frame portion, and further a second end portion suited to be bend forming an earpiece, which temple bar is made of a plastic material and within a channel, which is extending at least along the length of the second temple bar end portion, a metal rod is fastened for the reinforcement of the rod of plastic material, and where at a positon on the earpiece an elastic resilient friction element is connected to the temple bar to provide a contact of touch with the back of a wearer's ear.
Background of the invention
Thus, temple bars are used within a set of eyeglass, which comprises an eyeglass frame portion and two temple bars connected with the eyeglass frame portion, which connection preferably is provided by means of respective hinge members which pivotably connect the temple bars with the eyeglass frame portion.
Through many years it is known art to manufacture temple bars of acetate. The pre- sent invention is the result that has been reached based on the background of the hereby encounted problems. On the other hand, the present invention may also find application to temple bars which consist of other types of plastic materials; nevertheless the following specification of the present invention below is explained specifically under reference to acetate.
It is known to provide the temple bars with friction elements which, as most practical, should be made exchangeable for the wearer. This friction element is often present in
shape of a tube which is drawn over a temple bar at a position located at the ear bend serving to provide contact of touch behind the wearer's ear. This feature has typically been employed at temple bars of metal with the purpose of providing comfort for the wearer, but also is employed in case of temple bars made of plastic materials. Here through, any direct contact between the plastic material and sweat, fats and other emanations, which may decompose the plastics, is avoided. On the other hand, such tubes may lead to a lesser degree of comfort because the edges of (he tube may be found uncomfortable for the wearer. Furthermore, the risk exists that me tube may slide along the temple bar and thus no longer maintains an optimal position at the earpiece.
According to US 6 045 221 it is proposed to position a frictional element in embedded manner in a recess located on the side of the first end portion of the temple bar being intended to provide connection with an eyeglass frame portion. Plastics, and especially acetate, are very sensitive to notch fatiguing influences which necessitates that, within the provided shape of the temple bars, any abrupt dimensional transitions cannot be allowed, in particular at the earpieces. This introduces limitations unto the choice of shape of the temple bar and to the reinforcing element. Thus, in the US 6 045 221 a friction element to be employed at the earpiece is shown as having the shape of a tube.
Acetate is a soft plastic material and therefore suited to form an ear adapting bending by bending within a plane, i.e. to be suited to be positioned behind a wearer's ear and furthermore to be bend within another plane to be adapted to the wearer's head shape. Due to the softness of acetate the temple bars have earlier had to attain a considerable size, which gave difficulties to provide the bending and furthermore made a set of eyeglass unwantedly heavy as well as resulted in an occupation of much space behind the ear.
It is wanted to minimize the size of the temple bar to improve the comfort for the wearer, both in relation to weight and size. But hereby, unfortunately, both the strength as well as the stability of shape becomes insufficient. Therefore, it is also known to employ a stiffening reinforcement element in shape of a metal rod being comprised within a longitudinal boring or channel in the temple bar. This is by way of example disclosed in US 1 736 953. Here through it becomes possible to bend the plastic material and to provide a reinforcement of the rod of plastic material, thereby safeguarding a stabile shape of the bending due the properties of the metal rod and due
to a simultaneous increase in strength. Furthermore, such a kind of temple bar may easily be adapted by an optician or by the wearer without any risk for damaging the pair of eyeglass. To avoid that the metal rod slides out of the temple bar it is held in place by means of gluing. However, experience shows that translational tensions, which are appearing during the bending process while bending the rod of plastic material to attain adaptation to a wearer, may well be able to overpower the holding power being attained from a glued joint. Therefore another manner of fixation is required which safeguards that the metal rod remains in a fix-connected position in relation to the plastic rod.
Furthermore, according to US 4 563 066 a temple bar is known which is manufactured of a metal rod. At the end portion at the earpiece the metal rod is covered by a bushing of plastic material which is fastened onto the metal rod. Within this area the metal rod is provided with sawtooth shaped protrusions which together with a gluing safeguard that the surrounding plastic sheath remains kept fastened onto the metal rod. The surrounding plastic sheath is comprised within a drip shaped terminating portion of a surrounding silicone rubber sheath which is fastened onto the metal rod at the earpiece. No possibility is provided for exchange of the combined plastic material sili- cone rubber surrounding sheath.
In relation to temple bars of plastic material a need thus is present for providing in a simple manner an integration of as well the friction element as the reinforcing element in the rod of plastic material, thus enabling that an optician or a wearer easily them- selves are enabled to adapt the shape of the temple bar, and whereby the wearer self easily and in a simple manner is able to exchange the friction element.
The purpose of the invention
The invention serves the purpose to introduce a temple bar and a method to the manu- facturing of such a temple bar which avoids the problems being associated with the temple bars belonging to the stale of the art, and thus in a simple manner makes it possible to integrate a friction element and a reinforcing element within the plastic rod and also makes it possible that an optician or a wearer easily can provide an adaptation of the shape of the temple bar as well as easily and in a simple manner can pro- vide an exchange of the friction element.
Specification of the invention
This is achieved according to the invention at a temple bar of the type mentioned in the introduction and peculiar in that the channel is connected with a groove or notch provided on the side of the plastic rod which is turning inwards within the earpiece, and in that the metal rod is provided with first sidewards oriented protrusions adapted to be fastened within the plastic rod and with second sidewards oriented protrusions able to provide releasable snap connection with apertures provided in the friction element. The method according to the invention is characterized by comprising the following steps:
a - Manufacture a plastic rod exhibiting the basic shape of a temple bar,
b - manufacture of a channel in the plastic rod,
c - manufacture of a sidewards oriented groove or notch in the plastic rod extending from one side edge and staying in connection with the channel,
d - manufacture of a metal rod which is longer than the length of the notch and comprising first sidewards oriented protrusions and second sidewards oriented protrusions on opposed side edges of a central portion of the metal rod between end portions which are not provided with protrusions,
e - placing the metal rod in the notch whereby the end portions of the metal rod become inserted into the channel - possibly by bending the plastic rod and the metal rod in case an internal channel is present,
f - fastening the first sidewards oriented protrusions in the plastic rod while simultaneously exerting a pressure to establish a safe grip between the first sidewards oriented protrusions and the plastic rod,
g - manufacture of an elastic resilient friction element comprising apertures able to cooperate with the second sidewards oriented protrusions,
h - placing the friction element in the notch whereby the second sidewards oriented protrusions are being pressed into the apertures of the friction element to provide an elastic releasable snap connection,
i - bending of the temple bar to provide an earpiece.
Thus, by means of the present invention it becomes possible to solve the problem connected with the state of the art according to which a reinforcing element was fas- tened unto the plastic rod by means of gluing. The resulting experience has been that
the gluing was insufficient as the forces, which were acting while bending the temple bar, caused a breakage of the gluing to take place.
Furthermore, by means of the present invention a reinforcing of the plastic rod is pro- vided in that the reinforcing element, in shape of the metal rod, is brought to run on either side of the notch and into channels which are established within the metal rod. By means hereof a risk of breakage due to notch fatigue in the notch becomes avoided. In that the metal rod is provided with sidewards oriented protrusions a safe fastening in the plastic rod is achieved when the fastening is established preferably by means of welding. Preferred, the welding is an ultrasound welding during which welding a pressure is exerted so that the sidewards oriented protrusions are being inserted into and become fastened in the plastic rod.
Because the metal rod comprises second sidewards oriented protrusions, which are able to provide a releasable snap grip with a friction element at the earpiece, it in this manner becomes easy for a wearer to exchange the friction element. Because the friction element is put in position in a notch in the plastic rod no sharp edges will be pre- sent which can become uncomfortable for the wearer.
Because the plastic rod is reinforced by means of a completely or only in part comprised metal rod it thus becomes possible to employ small dimensions and due hereto the temple bar will not be present at human ears in shape of a large volume feature.
According to a further embodiment the temple bar according to the invention is characterized in that the protrusions at their connections with the metal rod exhibit smaller cross sections than the cross sections of the protrusions at a certain distance from the metal rod.
Both the first and the second sidewards oriented protrusions can exhibit the same shape or they can exhibit different shapes. On the other hand it is preferred that they exhibit the depicted cross section shape, by way of example through exhibiting a mushroom shape or the shape of an arrow. Hereby the inserting into the plastic mate- rial will provide a safe grip and furthermore a safe holding-in-place by means of the first sidewards oriented protrusions. The second sidewards oriented protrusions may
easily establish a snap grip function when they are present exhibiting mushroom shape or in shape of arrows.
According to a further embodiment the temple bar according to the invention is char- acterized in that the friction element is provided as an elastic resilient element which comprises sidewards apertures for occupying the second sidewards oriented protrusions due to the elastic resiliency of the friction element material.
To achieve an in particular easy snap function it is preferred that the friction element is manufactured of an elastic resilient material. Hereby the wearer in a particularly easy manner is able to establish the snap grip function. Simultaneously the elastic resiliency of the friction element material will cooperate to a safe keeping-in-place of the friction element. Furthermore, the elastic resiliency makes it easy for the wearer to provide the snap gripping as compared to friction elements by which a hard material is being provided.
According to a further embodiment according to the invention the temple bar is characterized in that the first sidewards oriented protrusions are fastened in the plastic rod and are comprised within it by means of welding.
As above mentioned welding provides a preferred embodiment for embedding the first sidewards oriented protrusions in the rod of plastic material. By providing the embedding during a welding the soft made plastic material in a safe manner is brought to surround the sidewards oriented protrusions while these, simultaneously, are being pressed into the plastic material.
According to a further embodiment according to the invention the temple bar is characterized in that the end portions of the metal rod do not comprise protrusions and in that the metal rod is longer than the length of the notch whereby the end portions ex- tend into the channel in shape of an inner channel on either side of the notch.
To safeguard an easily carried out mounting the end portions of the metal rod on either side of the first and second protrusions should exhibit being a smooth rod or of plate shape. In this manner it is in a simple way made easy that these end portions are enabled to extend into a channel on either side of the protrusion. Hereby an efficient reinforcing of the plastic material is achieved in the range where the notch is provided.
In this manner the risk that the plastic material breaks is avoided when an earpiece is made. Thus, an earpiece may in a safe manner be provided by an optician or by the wearer. It should be added, that the reinforcing metal rod does not only safeguard against a breakage of the plastic material within the bending. It furthermore provides stability for the shape of the temple bar. This stability of shape not only is provided within the plane of the earpiece, but does furthermore establish stability of shape when a bending to provide adaptation to the wearer's head shape is provided being carried out in a direction running perpendicular to that of the earpiece.
According to a further 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 may be chosen 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 to the manufacturing of the metal rod because this material exhibits a very low weight. On the other hand, other metals may be employed when manufacturing the metal rod. According to a further embodiment according to the invention the temple bar is characterized in that the plastic rod exhibits a rectangular cross section and in that the first and the second sidewards oriented protrusions are being shaped on two opposing sides of the metal rod. Though the metal rod may be manufactured exhibiting a circular or an oval cross section it is preferred that the rod exhibits a rectangular cross section. It is furthermore preferred that the plastic rod exhibits a rectangular cross section. With this shape the first and second protrusions on the metal rod are provided on the two narrow opposing sides of the metal rod. These protrusions may be provided by moulding or by cutting- out the metal rod from a metal sheet.
When the rectangular metal rod is being placed and embedded in the plastic rod the second protrusions automatically will be positioned in the aperture of the notch within the rectangular cross section of the plastic rod. This is safeguarded by positioning the metal rod within a central notch in the plastic rod.
According to a further embodiment according to the invention the temple bar is characterized in that the friction element exhibits an external shape which corresponds to that of the notch so that a cross section of the temple bar just outside the notch corresponds to the cross section of the temple bar in areas at either side of the notch.
When the friction element attains an external shape that corresponds to the size of the notch no sharp transitions will be present. The friction element will be positioned within the notch in such a manner that the cross section of the temple bar in areas on either side of the notch will correspond to the cross section just outside the friction element. It may be expressed in the manner that the friction element is positioned countersunk in the temple bar and the external surfaces are forming a common plane with the external surfaces of the plastic rod.
According to a further embodiment according to the invention the temple bar is char- acterized in that the channel of the plastic rod exhibits a sidewards oriented aperture extending from the notch to the second end portion of the temple bar whereby a portion of the metal rod is protruding from the sidewards oriented aperture of the channel.
The channel of the plastic rod may be a closed channel - or may be an internal chan- nel which only is provided with apertures at the endings of the channel or possibly the channel is manufactured as a channel with a sidewards oriented aperture. In which case the channel can be characterized as an open channel. When this channel extends from the ending of the second temple bar end portion to the notch it is possible to put the metal rod in place by being inserted through the sidewards oriented aperture. At such an embodiment it is preferred that the metal rod comprises an outermost end portion which is going to be put in position in a closed channel at the second temple bar end portion in a direction which points away from the eyeglass frame portion.
By means of this structure the metal rod simultaneously may form an integral part of the hinge member which is employed for the fastening of the temple bar to the eyeglass frame portion. In case closed internal channels are employed, in which case the
metal element is brought not to extend along the whole length of the plastic rod; it is required to employ a further metal rod. This has to be fastened in the acetate and simultaneously be provided with a hinge member which is able to cooperate with a hinge member on the eyeglass frame portion. By employing a channel comprising a side- wards oriented aperture along the larger portion of its length it is made possible to achieve a more simple mounting of the hinge portion simultaneously with providing a reinforcement of (he plastic rod.
According to a further embodiment according to the invention the temple bar is char- acterized in that the plastic rod within a range between the notch and the sidewards oriented aperture cover the side surfaces of the metal rod.
To safeguard the presence of a smooth surface at the earpiece it is preferred that the plastic rod comprises material on either side of the notch. Even when a channel com- prising a sidewards oriented aperture is employed it is preferred, at least within an area alongside the notch, that material is present exhibiting such an extension that the cross sections of the plastic rod on either side of the notch are equal. This allows the friction element to be positioned between items of plastic material. In case the plastic rod does not contain material which covers the side of the metal rod, which is protrud- ing from the sidewards oriented aperture of the channel, the friction element is going to be placed in a notch which only comprises a termination at only one end of the friction element. Such an embodiment is also possible.
Description of the Drawing
The invention is further being specified below under reference to the drawing in which:
Fig. 1 illustrates the various steps belonging to the method employed at the manufacturing of a temple bar according to the invention,
Fig. 2 is a side view of a first embodiment of a temple bar comprising an internal channel,
Fig. 3 in part is a view of a set of eyeglass according to another embodiment of a temple bar according to the invention comprising an open channel,
Fig. 4 illustrates a detailed view of the temple bar according to Fig. 3,
Fig. 5 illustrates some single elements which form part of the kind of structure being employed at the temple bar according to Figs. 3 and 4,
Fig. 6 illustrates a temple bar according to the invention after being bend and made ready for being mounted within a set of eyeglass, and
Fig. 7 illustrates by way of example different embodiments of the first and of second sidewards oriented protrusions.
Detailed Description of the invention
Within Fig. 1 single steps A through K are illustrating the method employed at the manufacturing of the temple bar. According to step A a plastic rod 1 of acetate is provided which comprises a channel 2 and a sidewards oriented notch 3.
According to step B a reinforcing metal rod 4 is illustrated. The metal rod 4 comprises first sidewards oriented protrusions S and second sidewards oriented protrusions 6 which are located opposingly in relation to the first sidewards oriented protrusions.
According to step C it is illustrated that the metal rod 4 is placed in the plastic rod with the first and second sidewards oriented protrusions positioned outwardly from the notch 3. The metal rod exhibits, at each side section 7 of a section 8 with the side- wards oriented protrusions 5, 6, smooth surface areas which are able to be received in the channel 2.
According to step D it is illustrated that the side sections 7 of the metal element (not shown at step D) are placed in the channel 2, and that the metal rod 4 is exhibiting a vaguely bend curved shape.
According to step E a welding body 9 is being pressed against the metal rod and by welding thus fastening it in the plastic rod 1 and simultaneously positioning it while maintaining its shape in the plastic rod 1.
According to step F the finished shape is illustrated by which the metal rod 4 is comprised fittingly in the plastic rod 1.
According to step G it is illustrated how the open accessable second protrusions 6 thus are made freely accessable at the side edge of the plastic rod.
According to step H a friction element 27 is illustrated while being pressed into the notch 3. The friction element 27 comprises a series of apertures 37 in which the second protrusions 6 are received by means of a releasable snap grip. According to step I a finished temple bar comprising a straight shape is illustrated. It is illustrated that a metal element 10 is mounted on the plastic rod 1. The metal element 10 is provided with a hinge member 11 able to cooperate with a hinge member on an eyeglass frame portion. According to step J it is illustrated that a bending operation 12 has been carried out to provide an earpiece 13. At the internal side of the earpiece within the notch 3 the friction element 27 is provided.
According to step K it is illustrated how the plastic rod 1 furthermore has been brought to attain a curved shape which adapts itself to the wearer's head shape. In final shape, as illustrated within Fig. 1, the temple bar is ready to be mounted unto an eyeglass frame portion.
In Fig. 2 a metal rod is illustrated which consists of two parts, i.e. a first part 13 and a second part 14. The first part 13 is shaped as explained above under reference to Fig. 1. The two parts 13 and 14 are adapted to be positioned within the plastic rod 1 as illustrated below in Fig. 2. Hereof it can be seen that the second part 14 of the metal rod includes an extension outside the plastic rod 1 able to provide the hinge member 11 or to occupy a position outside the plastic rod.
The second part 14 may be brought in place within the plastic rod 1 in that a transitional channel is provided within the plastic rod able to occupy an as longitudinal element shaped part 15 and furthermore that a milled slot able to occupy a plate shaped portion of the second part 14 is provided.
According to Fig. 3 a half-set 17 of a pair of eyeglass is illustrated. The half-set 17 comprises an eyeglass half-frame 18 which is shown including a hinge member 19 cooperating with a hinge member 11 being positioned on a plastic rod 1. The half- frame 18 comprises, as according to the state of the art, a lens 20 and a nose bridge support pad 21.
According to Fig. 4, in enlarged scale, an earpiece 13 is illustrated. Hereby it is illustrated how the friction element 27 is arranged being comprised within the notch 3, so that the surfaces of the friction element and the surfaces of the plastic rod 1 both share a common plane configuration. Hereby, along the longitudinal length, the temple bar is brought to exhibit an unvarying cross sectional shape.
According to Fig. 5 three items are illustrated which form part of the temple bar illustrated within Figs. 3 and 4. The illustrated items are a plastic rod 1 , a metal rod 4 and a friction element 27.
According to Figs. 3 through S it is shown that the channel 2 is open whereby a transitional metal rod 4 is protruding from the plastic rod through a sidewards oriented aperture 22 belonging to the channel 2. According to Fig. 6 an area 23 is illustrated at which the plastic item is protruding besides the notch 3. Here through, at both ends of the notch, respective protruding portions of plastic are provided between which the friction element 27 is arranged.
According to the embodiment illustrated in Figs. 3 through 5 the metal rod is, along the complete length of the rod, shown as protruding from the plastic item, and at the frame end of the metal rod 4 this rod is embodied to be able to be connected to a hinge member 11. As an alternative embodiment the hinge member 11 may be provided as being integral with the metal rod 4 by being shaped by means of a sharp-bending of the metal rod 4.
In Fig. 6 a temple bar is illustrated being shaped according to the principle which also is shown illustrated in Figs. 3 through 5. According to this embodiment the metal rod 4 is protruding from the sidewards aperture of the channel within the plastic rod 1. In Fig. 6 it is illustrated how it is possible to shape the plastic material 3- dimensionally, i.e. not only to provide an earpiece 13 which is comprised within a geometrically flat plane. Thus, as shown illustrated leftmost in Fig. 6, to achieve adaptation to the wearer's head a curved shape 24 is provided. In the lowermost portion of Fig. 6 it is illustrated how an S-shaped bending 25 at the earpiece is provided. The attained 3-dimensional shape with which the temple bar may be provided will remain
and can be provided without any risk of breaking the plastic rod 1 due to milled slot notch effects at the notch 3 at the bending process.
According to Fig. 7 different embodiments of the first sidewards oriented protrusions S and the second sidewards oriented protrusions 6 within the section 8 of the metal rod are illustrated. Although the protrusions S and 6 may be shaped as in a straight line running protrusions exhibiting the same cross sectional shape in the complete extension of them from a central portion 26 of the metal rod 4 a mushroom shape or the shape of an arrow is preferred as illustrated uppermost in the Fig. or they may attain an edges comprising configuration or a circular shaped configuration as illustrated lowermost in the Fig. The embodiments of the protrusions S and 6 have in common that they exhibit a smaller cross section where they are connected to the central portion 26 of the metal rod than at a location lying more remote from the central portion 26. Hereby an especially safe embedding of the first protrusions S within the plastic material is obtained.
The second sidewards oriented protrusions 6 will due to their shape establish an especially safe gripping with the apertures 37 in the friction element 27, because they are able to slip into and be kept in place within these apertures by means of snap-gripping. The snap-gripping is further amplified in case the friction element is manufactured of an elastic resilient material, by way of example of rubber.
Dimensions for practical use for plastic rods and metal rods exhibiting rectangular shape can by way of example be mentioned. The thickness of such a plastic rod will typically be between 2 and 5 mm, and the height will typically be between 3 and 7 mm. The thickness of a metal rod to be comprised within a plastic rod will be between 0.5 and 1.5 mm. The height of the protrusions will typically be between 0.7 and 2 mm.