Friction hinge

Abstract

Hinge for pivoting connection of a temple and a frame in a spectacle frame, comprising: - a first part having an upper flange and a lower flange, a first hole in the upper flange providing a tight fit for a head of a locking pin, a recess in the lower flange providing a housing for a cylindrical body of the locking pin; - a second part having a second hole, the second hole having a higher surface roughness than the cylindrical body of the locking pin, whereby the surface friction between the bushing and the second hole is higher than the surface friction between the bushing and the locking pin; - a bushing having an inner hole; - a locking pin having a head and a cylindrical body. The second part with the bushing is inserted between the upper flange and the lower flange of the first part. The locking pin is inserted through the first hole and the inner hole of the bushing and accommodated in the recess. Thereby the first part and the locking pin are pivotally connected to the second part and the bushing.

Description

TECHNICAL FIELD

[0001] The present invention relates to a hinge for pivotally connecting a temple and a frame in a spectacle frame, and to a pair of spectacles comprising such a hinge.

[0002] It is to be understood that the spectacles in the present application are to be understood as spectacles with a frame surrounding the entire periphery of the lens, spectacles with a half-frame surrounding only a part of the periphery of the lens, and rimless spectacles with the temple directly attached to the lens without a frame.

[0003] More precisely, the present invention relates to a hinge for pivotally connecting two components, such as a temple and a frame in a spectacle frame, or two parts of a temple, wherein the hinge comprises:

[0004] - a first component provided with an upper flange and a lower flange at the end of the first component, wherein the upper flange and the lower flange are spaced apart by a distance x, and wherein a first hole is provided in the upper flange, the first hole having a diameter y;

[0005] - a second component provided with a through-going second hole at the end of the second component, the through-going second hole defining a cylindrical inner wall, wherein the second hole has a diameter z, and wherein the distance k between the upper surface and the lower surface of the second component is smaller than the distance x between the upper flange and the lower flange;

[0006] - a bushing made of an elastic material is provided in the through-going second hole, the bushing having an axis of symmetry, and wherein the length of the bushing along the axis of symmetry is equal to or greater than the distance k between the upper surface and the lower surface of the second component but smaller than the distance x between the upper flange and the lower flange, the bushing having an inner hole having a diameter l perpendicular to the axis of symmetry;

[0007] - a locking pin having a head defining an axis of symmetry and a cylindrical body portion, wherein in a cross-section perpendicular to the axis of symmetry, the head has a size such that the head can be accommodated in the first hole, and wherein the length of the body portion along the axis of symmetry is equal to or greater than the distance x between the upper flange and the lower flange, and wherein the diameter n of the body portion perpendicular to the axis of symmetry is equal to or greater than the diameter l of the inner hole of the bushing; such that by inserting the bushing in the second hole at the end of the second component, and inserting the end of the second component between the upper surface and the lower surface of the end of the first component, the first hole in the upper flange will telescope in the inner hole of the bushing, whereby the body portion of the locking pin can be inserted in the inner hole of the bushing, and whereby the two components are pivotally connected. BACKGROUND

[0008] In the art, it is well known to provide a hinge structure between the temple and the frame of a spectacle, wherein such hinges have a number of different characteristics depending on the specific spectacle frame to be manufactured.

[0009] One of the desired aspects of a hinge is the ability of the hinge to keep the temple in a substantially fixed position relative to the frame of the eyeglasses, where "substantially fixed position" is to be understood in this context as requiring a small amount of force to pivot the temple relative to the frame, however the temple itself cannot pivot. The force necessary does not deform or otherwise adversely affect any part of the eyeglasses frame.

[0010] For this purpose, a number of different designs have been considered, but in all of these designs the hinge structure relies on a relatively complex structure involving springs or pure friction, the pure friction being obtained by sufficiently tightening the screws connecting the temple to the frame in order to generate the required friction, thereby keeping the temple in a substantially fixed position relative to the frame.

[0011] The common denominator of these prior art solutions is that they are relatively complex, or do not meet the required purpose due to loosening of the connection between the temple and the frame as a result of wear, which prior art solutions need to be readjusted after a certain period of time.

[0012] From US 4,428,094 a hinge of the kind described in the preamble is known. In this hinge a rotation is possible between the bushing and the second hole or between the bushing and the locking pin. It is therefore not clear whether a rotation will occur relative to the other elements. The mutual rotation can therefore occur in such a way that the bushing can rotate relative to the pin and the hole. This is a disadvantage because the force for achieving the rotation cannot be controlled. Furthermore, the wear of the hinge parts can not be controlled because it is not fixed which elements move relative to the other elements. Furthermore, it is not taught how to keep the friction between the hinged elements constant over a long period of time.

[0013] Object of the invention

[0014] It is therefore an object of the present invention to alleviate the disadvantages of the prior art by providing a hinge structure that can reliably keep the temple in a substantially fixed position relative to the frame, and at the same time the hinge structure is relatively small, compact and unobtrusive, and furthermore can be manufactured in a simple manner. It is furthermore an object to keep the friction between the hinged elements constant over a long period of time. Summary of the invention

[0015] The invention solves this problem by providing a hinge as described in the preamble, wherein the hinge is characterized in that the roughness value Ra of the surface roughness of the wall of the second hole is greater than the roughness value Ra of the locking pin, whereby the friction between the bushing and the wall of the second hole is higher than the friction between the inner hole in the bushing and the locking pin.

[0016] In particular, the relative tight fit between the hole in which the bushing is located and the bushing and the tight fit between the locking pin and the bushing provide sufficient frictional forces to enable the temple to be held in a substantially fixed position relative to the frame, i.e. some action is required to pivot the temple relative to the frame due to the frictional forces generated in the hinge. In this way, the frictional forces between the elements of the hinge can be maintained for a long period of time. In fact, the resilient / elastic material is held under compression within the hinge structure to provide and maintain the required frictional forces even after wear as the resilient material will push against the surfaces thereby maintaining the required frictional forces.

[0017] At the same time, the structure is relatively simple as the locking pin is held partly by the bushing and partly by the hole provided in the upper flange of the end of the first component.

[0018] By providing different roughness values, whereby the frictional forces between the bushing and the second hole are different to the frictional forces between the bushing and the locking pin, it is possible to control which components move relative to which components during the pivoting movement of the hinge. The roughness value Ra represents the surface friction between two components, so that two components have a greater frictional force between them than between other two components, it is clear that the components with the smallest frictional force, i.e. with the smallest roughness value, will move relative to each other before the components with the higher roughness, i.e. the greater frictional force, begin to move.

[0019] In this way, as mentioned in the present embodiment, movement can be generated between the locking pin and the bushing during the pivoting of the hinge mechanism. In this way, it is possible to control the frictional forces for a long period of time by appropriately selecting the materials and the characteristics of the materials and the elements used for the hinge elements.

[0020] It will be appreciated that at least in the present application, glasses should be understood to mean glasses with a frame surrounding the entire periphery of the lens, half-rim glasses with a frame surrounding only part of the periphery of the lens and rimless glasses with the temples attached directly to the lens without a frame.

[0021] In a more advantageous embodiment of the application, the frictional forces are further increased as the diameter n of the body portion of the locking pin perpendicular to the diameter of the symmetry axis is greater than the diameter I of the inner hole of the bushing and wherein the bushing can be deformed such that the excess material is squeezed into the space formed by the difference between the length of the distance x between the upper flange and the lower flange and the distance k between the upper surface and the lower surface of the second component.

[0022] In this way, the insertion of the cylindrical body portion of the locking pin into the bushing will deform the bushing which is held in place securely by the second hole in the second component such that the bushing material will be squeezed out of the second hole in the second component thereby forming a further resilient bearing between the first component and the second component. Furthermore, the deformation will increase the frictional fit between the locking pin and the bushing, between the bushing and the second component.

[0023] In a further advantageous embodiment of the application, the lower flange is provided with a recess adapted to receive the end of the locking pin, said recess being formed on the side of the lower flange facing the upper flange.

[0024] In this way, a guide and a direction for the end of the locking pin is formed in the lower flange of the first part, so that as the locking pin is inserted through the first hole in the upper flange of the first part and through the second hole in the second part, the end of the locking pin will remain in the recess formed in the lower flange. At the same time, the head of the locking pin will remain in the hole in the upper flange. Thereby, the two parts of the hinge are pivotally locked together by the locking pin in a stable and secure manner.

[0025] In a further advantageous embodiment of the application, the outer diameter of the bushing l2 perpendicular to the symmetry axis is greater than the diameter z of the second hole when the bushing is not arranged in the second hole.

[0026] By providing a bushing with a diameter greater than the second hole in which it is intended to be mounted, the bushing needs to be deformed during the mounting of the bushing into the second hole. During the mounting / assembly of the bushing, a part of the excess material will be forced out of the hole along the two side edges of the second hole as well as along the inner diameter of the bushing when the bushing is arranged in the second hole, due to the compression of the bushing, than when the bushing is not inserted.

[0027] Furthermore, when the locking pin is inserted into the bushing, the locking pin will also deform the bushing, further causing the excess material to be forced out of the hole, so that the excess material of the bushing will form a spring bearing between the first part and the second part. By correctly dimensioning the bushing and at the same time choosing suitable material properties, it is possible to provide the deformation of the spring material of the bushing so that the yield stress of the material is reached, whereby the bushing will deform substantially uniformly so that the bearing will be distributed uniformly in the space between the end of the first part and the end of the second part.

[0028] In a further advantageous embodiment of the application, the head of the locking pin is press-fitted into the first hole in the upper flange.

[0029] By press-fitting the head of the locking pin into the first hole in the upper flange of the first part, the locking pin is fixed in relation to the first hole so that the locking pin cannot rotate in the first hole, and at the same time the locking pin is safely retained in the hinge structure, ensuring that the hinge remains intact during use.

[0030] Furthermore, due to the provision of the bushing and in some embodiments the design of the relative friction between the different parts, the application can be designed so that the frictional engagement between the pivoting parts is such that the locking pin is not forced to rotate in relation to the first part. Thus, a very stable and secure connection is formed in the hinge between the locking pin arranged in the first part and the second hole in the second part.

[0031] In a more advantageous embodiment of the application, the first and second parts are made of titanium, and wherein the bushing is made of a polymer material having a Shore A hardness of 50 or more, preferably 60 or more. By this selection of materials, a very light structure can be formed, while at the same time the structure has superior strength properties due to the inherent strength properties of titanium. Furthermore, by selecting the bushing from a polymer material having a Shore A hardness of 50 or more, wear in the hinge joint can be neglected, thereby ensuring a long, stable service life of the hinge structure.

[0032] Of the many polymers suitable for use in the present application, it is particularly preferred that the polymer material is of the polyamide type, in particular PA6 or PA11.

[0033] The present application also relates to a spectacle frame made of an elastic metal material, said spectacle frame comprising a frame adapted to accommodate a lens and two temples arranged on either side of the frame, wherein the temples are connected to the frame by two hinges.

[0034] It is clear that a spectacle frame made with a hinge structure as described above will obtain and enjoy the same advantages as the hinge structure described above. BRIEF DESCRIPTION OF DRAWINGS

[0035] The present application will be described with reference to the accompanying drawings, in which:

[0036] Figure 1 An example of a full-rimmed spectacle is shown;

[0037] Figure 2 An example of a rimless spectacle is shown;

[0038] Figure 3 A hinge structure is shown before insertion of the locking pin;

[0039] Figure 4 A hinge structure is shown after the locking pin is received in the recess;

[0040] Figure 5 A bushing is shown. DETAILED DESCRIPTION

[0041] Figure 1 An example of a frame of a spectacle 1 is shown. The spectacle frame typically comprises a pair of frames 2, wherein the frames 2 are provided with frame means for holding corrective lenses 6. From the frames 2, two temples 3 typically extend, so that the user can wear the spectacle 1 by, for example, placing the temples over the ears and providing a nose pad 4 on the nose. As is known, a hinge 5 is provided between the temples 3 and the frames 2, so that the temples can be pivoted to a position in which the longitudinal extent of the temples 3 is substantially parallel to the plane of the frames 2. This is typically done for storage of the spectacle.

[0042] Figure 2 An example of a pair of glasses of the no-frame type is shown, in which the temples 3 are mounted directly on / in the lenses 6.

[0043] However, it is desirable that the hinge structure 5 keeps the temples 3 in a substantially fixed position relative to the frame 2, in order to provide comfort to the wearer. In some cases, the relative distance between the temples 3 can be such that the temples press against the sides of the head of the user, in order to relatively keep the glasses fixed relative to the wearer.

[0044] The present invention aims to provide a novel and inventive hinge structure 5, which comprises a number of advantageous technical features. Furthermore, the present invention also comprises a pair of glasses comprising such a hinge.

[0045] The main principles of the present invention will be explained with reference to Figure 3 and Figure 4 , and Figure 3 and Figure 4 show cross-sectional views of the hinge structure before and after insertion of the locking pin.

[0046] In Figure 3 , the hinge structure comprises a first part 10, for example a temple. The end of the first part is provided with an upper flange 12 and a lower flange 14. The distance between the upper flange 12 and the lower flange 14 is x. The upper flange 12 is provided with a first hole 16 having a diameter y. The lower flange 14 is provided with a recess 18. When a locking pin 20 is inserted through the first hole 16, the body portion 22 of the locking pin, in particular the end 22' of the body portion of the locking pin, will be accommodated in the recess 18, as shown in Figure 4 .

[0047] The locking pin 20 further comprises a head portion 24. The head portion 24 has a dimension perpendicular to the axis of symmetry 26, such that a tight fit can be formed between the head portion 24 of the locking pin 20 and the first hole 16 provided in the upper flange when the locking pin is inserted in the locked position, as shown in Figure 4 .

[0048] The other part of the hinge comprises a second part 30. At the end of the second part a second hole 32 is provided. The second hole 32 is a through hole, such that the second hole defines a cylindrical inner wall 34. The second hole has a diameter z. Furthermore, the thickness k of the second part, i.e. the distance between the upper side and the lower side of the second part, is k, wherein k is smaller than the distance x between the upper flange 12 and the lower flange 14 of the first part. In this way, the second part 30 can be inserted between the flanges 12, 14 of the first part 10 with a certain clearance.

[0049] A bushing 40 is arranged in the second hole of the second part 30. In the present embodiment, the bushing has an extension along the symmetry axis 26 which is greater than the thickness of the second part 30, but less than the distance x between the upper flange 12 and the lower flange 14 of the first part 10.

[0050] Furthermore, as Figure 5 The bushing 40 as shown has an inner hole 42 with a diameter a perpendicular to the symmetry axis.

[0051] With reference still to Figure 4 the locking pin 20 has been inserted through the first hole 16 such that the body portion 22 of the locking pin 20 fits in the inner hole 42 of the bushing 40. Furthermore, the end 22' of the body portion 22 of the locking pin 20 is accommodated in the recess 18 of the lower flange 14. During insertion of the locking pin 20, the bushing 40 is deformed such that excess bushing material is forced into the space between the first part and the second part. This excess bushing material 44 forms a bearing between the first part 10 and the second part 30 such that a stable, secure and elastic connection is formed between the first part 10 and the second part 30. It will be appreciated that the remaining bushing material will remain in the immediate vicinity of the locking pin and that the deformation will not cause disintegration or failure of the bushing material. This can be controlled by applying the force from the locking pin slowly and / or heating the bushing material carefully and / or selecting the bushing material such that any deformation does not cause disintegration or failure.

[0052] In order to enable the bushing to be deformed as Figure 4 shown, the bushing can advantageously be made of an elastic polymer material, such as polyamide. In particular, PA6 is known for its hardness, strength, ductility, wear resistance and chemical resistance, and thus PA6 is more or less considered a general purpose polymer material for these types of bearings. Furthermore, a further derived polyamide PA11 can be used, wherein PA11 has a higher hardness and ductility and thus can be more difficult to deform as Figure 4 shown, but still provides excellent wear properties, providing a longer service life.

[0053] Furthermore, the polymer should be selected such that the Shore A hardness (according to ASTM D2240 and ASTM D 1414) is in the range of 50 to 60, in order to provide sufficient elasticity to deform by inserting the locking pin 20 through the bushing, and at the same time provide sufficient wear resistance and strength in order to form a stable and reliable hinge structure.

[0054] Although the various dimensions ensure that sufficient friction is created between the pivoting components, the surface roughness of the inner wall of the second bore can be selected to be higher than the surface roughness between the bushing and the body portion 22 of the locking pin. By selecting a surface roughness value (Ra) between the bushing and the second component that is higher than the surface roughness value between the body portion 22 of the locking pin 20 and the inner bore of the bushing, the hinge is designed such that a pivoting motion will occur between the body portion 22 of the locking pin and the inner bore of the bushing. For the sake of completeness, the roughness parameter is established in accordance with BS EN ISO 4287:2000 (British Standard), which corresponds to ISO 4287:1997 (European Standard). The parameter Ra is the arithmetic mean of the roughness profile.

Claims

1. Hinge for pivotally connecting a temple and a frame or two parts of a temple in eyeglasses, wherein the hinge comprises: - a first part provided with an upper flange and a lower flange at its end, wherein the upper flange and the lower flange are spaced apart by a distance, and wherein a first hole is provided in the upper flange, the first hole having a diameter; - a second part provided with a through-going second hole at its end, the through-going second hole defining a cylindrical inner wall, wherein the second hole has a diameter, and wherein the distance between the upper surface and the lower surface of the second part is smaller than the distance between the upper flange and the lower flange; - a bushing made of a resilient material is provided in the through-going second hole, the bushing having an axis of symmetry, and wherein the length of the bushing along the axis of symmetry is equal to or larger than the distance between the upper surface and the lower surface of the second part but smaller than the distance between the upper flange and the lower flange, the bushing having an inner hole, the inner hole having a diameter perpendicular to the axis of symmetry; - a locking pin having a head defining an axis of symmetry and a cylindrical body, wherein in a cross-section perpendicular to the axis of symmetry the head has a size such that the head can be accommodated in the first hole; such that by inserting the bushing in the second hole at the end of the second part and inserting the end of the second part between the upper surface and the lower surface of the end of the first part, the first hole in the upper flange is telescoped in the inner hole of the bushing, whereby the body of the locking pin can be inserted in the inner hole of the bushing, and whereby the two parts are pivotally connected, characterized in that the head of the locking pin is press-fitted in the first hole of the upper flange, whereby the locking pin is fixed with respect to the first hole such that the locking pin cannot rotate in the first hole, wherein the length of the body along the axis of symmetry is equal to or larger than the distance between the upper flange and the lower flange, and wherein the diameter of the body of the locking pin perpendicular to the axis of symmetry is equal to or larger than the diameter of the inner hole of the bushing; the surface roughness of the wall of the second hole has a larger roughness value than the roughness value of the locking pin, whereby the friction between the bushing and the wall of the second hole is higher than the friction between the inner hole of the bushing and the locking pin, and wherein the bushing can be deformed such that excess material is squeezed into the space formed by the difference between the distance between the upper flange and the lower flange and the distance between the upper surface and the lower surface of the second part, whereby a spring bearing is formed between the first part and the second part and the friction fit between the locking pin and the bushing, the bushing and the second part is increased. The lower flange is provided with a recess adapted to accommodate the end of the locking pin, the recess being formed on the side of the lower flange facing the upper flange. The outer diameter of the bushing perpendicular to the axis of symmetry is larger than the diameter of the second hole when the bushing is not placed in the second hole. The first part and the second part are made of titanium, and wherein the bushing is made of a polymeric material having a Shore A hardness above 50. The first part and the second part are made of titanium, and wherein the bushing is made of a polymeric material having a Shore A hardness above 60.

2. Hinge according to claim 1, characterized in that ​ 3. The hinge according to claim 1, characterized in that ​ 4. The hinge of claim 1, wherein ​ 5. The hinge of claim 1, wherein ​ 6. Hinge according to claim 4 or 5, characterized in that The polymeric material is a polyamide: PA6 or PA11.

7. A framed or unframed spectacle frame made of an elastic metal material, comprising a rim adapted to receive a lens or a frame mounted on a lens, and two temples disposed on either side of the rim, wherein the temples are connected to the rim or to the lens by two hinges according to claim 1, or wherein each of the temples comprises a hinge according to claim 1.

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