Patent Description:
Spectacles usually comprises a frame front and two side bars. The side bars are connected to the frame front by hinges. A hinge usually have a screw connection, connecting the side bar to the frame front. However, it is also known to have screw less connections.

Elastic hinges using split temples for providing the hinge function are known from <CIT> as well as <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

A disadvantage of spectacles using a hinge connection with a screw is that after long time use of the spectacles, the screw may be loose and may even fall off.

A disadvantage by screw less hinges for spectacles is that the connection between the frame front and the side bar is often unstable and slack, allowing the side bars to wiggle causing discomfort.

Hence, an improved hinge would be advantageous, and in particular a more stable hinge would be advantageous.

It is an object of the present invention to provide a stable screw less hinge for spectacles providing a stable connection between the frame front and the side bars.

The claimed invention is defined in the claims.

Thus, the above described object and several other objects are intended to be obtained in a first aspect of the invention by providing a hinge mechanism for spectacles comprising a frame front and two side bars, the frame front comprises two side sections for attaching the side bars to the frame front, each side section comprises a connection hole and a notch, and each side bar comprises an axial groove, the axial groove divides an upper end of the side bar in an outside elastic part and an inside elastic part, the outside elastic part and the inside elastic part both generates a spring force working towards the axial groove,.

The invention is particularly, but not exclusively, advantageous for obtaining a stable connection between the frame front and the side bars. The frame front comprises two u-shaped side sections. The side bars are attached to the u-shaped side sections. The side sections each comprises a connection hole and a notch, and further the side sections comprises an intermediate part between the connection hole and the notch. The outside elastic part is engaging the connection hole at one side of the intermediate part, and the inside elastic part is engaging the notch on the other side of the intermediate part. The spring force occurs because, when the side bar is mounted and attached to the frame front, the outside elastic part and the inside elastic part are bend away from each other by the intermediate part, so the outside elastic part and the inside elastic part both acts like blade springs applying a force towards the axial groove and the intermediate part, and thereby towards each other, so the side bar clings around the intermediate part between the connection hole and the notch.

When the side bar is in an open position, the spring force applied between the outside elastic part and the inside elastic part makes the outside elastic part engaging and pressuring against the side of the connection hole and the inside elastic part engaging and pressuring against the notch, the inside elastic part and the outside elastic part applying a pressure towards each other, fixing the side bar in a preferred and stable position.

Further, the connection hook, at the end of the outside elastic part, when the side bar is in an open position, is engaging against the side section preventing the side bar end especially the outside elastic part of the side bar from sliding out of the connection hole. If the outside elastic part slid out of the connection hole, the side bar would fall away from the frame front and the spectacle fall apart.

The side section comprises an inner side, the side section is basically u-shaped, and the inner side of the u-shape is the inner side of the side section. The inner side of the side section is facing towards the frame front, while the outer side of the side section is facing away from the frame front.

The connection hook is located at the top end of the outside elastic part, and when the outside elastic part is engaging the connection hole, at least part of the connection hook is located at the inner side of the u-shaped side section, and is engaging the side section in such a manner that it is preventing the outside elastic part from sliding out of the connection hole, for instance by the connection hook engaging the inner side of the u-shaped side section. The connection hook may for instance be engaging the inside edge of the connection hole.

According to an embodiment, the inside elastic part comprises a slanting part, and when the side bar is in an open position, the notch is engaging the slanting part. The inside elastic part comprises a straight part, a slanting part and a locking hook. When the side bar is in a closed position, the notch is engaging the straight part.

According to an embodiment, the connection hole comprises a near end and a remote end, and the connection hook comprises a topside and an underside, and when the side bar is in an open position, the topside of the connection hook is engaging the remote end of the connection hole, and the underside of the connection hook is engaging the near end of the connection hole.

The connection hole is an oblong hole in the side bar. The connection hole comprises a near end and a remote end, the near end is the end closest to the notch, and the remote end is the end furthest from the notch. The connection hook comprises a topside and an underside. The topside is also the top end of the outside elastic part. The underside is the side facing the axial groove.

The side bar can be in a closed position, an open position, in intermediate positions between the open position and a closed position, and further the side bar can be in an extended position beyond the open position. The open position is the position the sidebar will be in, when a person is wearing the spectacles. In the open position the side bars will form an angle close to <NUM> degrees with the frame front. In an open position the topside of the connection hook is engaging the remote end of the connection hole and the underside of the connection hook is engaging the near end of the connection hole. In an open position the notch is engaging the slanting part of the inside elastic part.

By the underside of the connection hook engaging the near end and the topside of the connection hook engaging the remote end of the connection hole, stability is achieved, so the side bar is stable and is not loose, and there will be no wiggling, slackness or play when the side bars are in an open position.

According to an embodiment, the connection hole comprises a near end and a remote end, and the connection hook comprises an topside and an underside, and when the side bar is in an closed position, the topside of the connection hook is engaging the remote end of the connection hole, and the underside of the connection hook is engaging the near end of the connection hole.

When the side bar is in a closed position, the side bar is substantially parallel with the frame front. The side bar is typically in a closed position, when a person is not wearing the spectacles and have folded the sides bar to be substantially parallel with the frame front and put the spectacles on a table or in a box.

When a side bar is in a closed position, the topside of the connection hook is engaging the remote end of the connection hole, and the underside of the connection hook is engaging the near end of the connection hole.

By the underside of the connection hook engaging the near end and the topside engaging the remote end of the connection hole, stability is achieved, so the side bar is stable and is not loose and there will be no wiggling, slackness or play when the side bars are in a closed position.

According to an embodiment, the notch narrows towards the bottom of the notch in a conical shape.

The notch is formed in a conical shape so that when the inside elastic part is engaging the notch, the spring force is wedging the inside elastic part into the bottom of the notch, thereby the inside elastic part will be firmly maintained in a fixed and stable position and there will be no wiggling, slackness or play.

According to an embodiment, the connection hole is an oblong hole, which narrows towards the near end and towards the remote end of the connection hole.

The connection hole preferable is an oblong hole, with two ends, a near end and a remote end. The near end of the connection hole is the end of the connection hole nearest to the notch. The near end is formed in a conical shape, just like the notch, and when the outside elastic part is engaging the near end, the spring force is wedging the outside elastic part into the bottom of the conical shaped near end, thereby the outside elastic part will be firmly maintained in a fixed and stable position and there will be no wiggling, slackness or play.

With the outside elastic part engaging the remote end and wedging into the bottom of the conical shaped near end, and the inside elastic part wedging into the bottom of the conical shaped notch, the side par is in a stable open position without wiggling, slackness or play.

According to an embodiment, the inside elastic part comprises a straight part, and when the notch is engaging the straight part, the spring force is moving the side bar towards a closed position.

When moving the side bar from an open to a closed position, the notch is pushed down the slanting part of the inside elastic part, over the chin and into the straight part. The chin is the point, where the slanting part and the straight part of the inside elastic part meets. When the notch has been moved into a position, where it is engaging the straight part, and the outside elastic part is engaging the near end of the connection hole, the intermediate part of the side section is in an oblique position between the outside elastic part and the inside elastic part, and the spring force will make the notch slide further down the straight part, until the side bar reaches the closed position, and thereby move the side bar to a closed position.

According to an embodiment, the inside elastic part comprises a slanting part, and when the notch is engaging the slanting part, the spring force is moving the side bar towards an open position.

When the notch is engaging the slanting part of the inside elastic part, and the outside elastic part is engaging the connection hole, the spring force will push the notch to slide down the slanting part, until the side bar reaches the open position, and thereby move the side bar to the open position. When the side bar reaches the open position, the topside of the connection hook is engaging the remote end of the connection hole, and the underside of the connection hook is engaging the near end of the connection hole. When the topside of the connection hook is engaging the remote end of the connection hole, the side bar will move no further and the notch will keep in contact with the slanting part.

Between the slanting part and the straight part of the inside elastic part, where the slanting part and the straight part meets, there is a chin. When the notch is engaging the inside elastic part above the chin, on the slanting part, the spring force will push the side bar towards an open position. When the notch is engaging the inside elastic part below the chin, on the straight part, the spring force will push the side bar towards a closed position.

According to an embodiment, the inside elastic part comprises a locking hook, and when the side bar is in an extended position, the locking hook is engaging the side section preventing the inside elastic part from sliding away from the notch.

The side bar is in an extended position, when the side bar is opened too much, it has been pushed beyond the open position by force. The notch is no longer engaging the slanting part, instead the notch is now engaging a constriction placed between the slanting part and the locking hook. The locking hook is engaging the side section, and/or the rim of the notch. The locking hook prevents the inside elastic part from moving further and disengage the side section, which would result in that the side bar would be released from the frame front and the spectacles would fall apart.

According to an embodiment, the side section comprises a slit between the connection hole and the notch.

When moving the side bar from an open to a closed position or visa versa, there is a point, where the notch, which is located at the end of the side bar, engages the chin between the straight part and the slanting part of the inside elastic part. In that position, when the chin of a side bar is engaging the surface of the notch, there may be no spring effect strong enough to make the side bar move towards an open or a closed position. To reduce the area, where there is no movement from the spring effect, the thickness of the notch is reduced by cutting a slit in the intermediate part between the connection hole and the notch. Hereby, the thickness of the notch is reduced in the area, where the chin engages the notch. Preferable the slit is placed on the outer side of the side section. Alternatively the slit may be placed on the inner side of the side section.

According to an embodiment, the side section comprises a slope covering a section of an intermediate part, between the connection hole and the notch, which is closest to the notch, the slope is sloping towards the notch.

Another way to reduce the thickness of the notch is to make a slope, which is sloping towards the notch, in the area, the intermediate part, of the side section between the connection hole and the notch. The slope may only cover a part of the area between the connection hole and the notch, the slope is then located in the part of the intermediate part closest to the notch sloping towards the notch. Also this embodiment reduces the thickness of the notch, where the inside elastic part engages the notch. Preferable the slope is placed on the outer side of the side section. Alternatively the slope may be placed on the inner side of the side section.

The two solutions may be combined to that a slit is cut in the intermediate part between the connection hole and the notch, and a slope is cut in the area of the slit closest to the notch.

Further, yet another alternative embodiment is to make the slit and the slope combine to form a curve that is gradually increasing the slope towards the notch.

In a second aspect, the invention relates to a method for applying a hinge mechanism for spectacles, the spectacles comprises a frame front and a side bar, wherein the method comprises:.

According to an embodiment, the connection hole comprises a near end and a remote end, and wherein the method further comprises, when the side bar is in an open position.

When in an open position the topside of the connection hook is engaging the remote end of the connection hole, and the underside of the connection hook is engaging the near end of the connection hole. Further, the notch is engaging the slanting part of the inside elastic part. When the notch is engaging the slanting part, the spring force would push to move the side bar further out, but by the topside of the connection hook engaging the remote end of the connection hole, further movement is prevented, the topside of the connection hook is pressed into the remote end.

According to an embodiment, the method further comprises.

When the side bar is positioned so the notch is in contact with the straight part of the inside elastic part, the spring force will push and thereby move the side bar to the closed position.

According to an embodiment, the method further comprises,.

When the side bar is positioned so the notch is in contact with the slanting part of the inside elastic part, the spring force will push and thereby move the side bar to the open position.

The first and second aspect of the present invention may each be combined with any of the other aspects.

The hinge mechanism according to the invention will now be described in more detail with regard to the accompanying figures. The figures show one way of implementing the present invention and is not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

<FIG> illustrates a pair of spectacles according to the invention. The spectacles <NUM> comprises a frame front <NUM> and two side bars <NUM>. The side bars <NUM> are attached to the frame front <NUM> by a hinge mechanism <NUM>. The frame front <NUM> comprises side sections <NUM>, one at each side of the frame front <NUM>. The side bars <NUM> are attached to the side sections <NUM>.

<FIG> illustrates a side section <NUM> of the frame front <NUM> and the upper end <NUM> of the side bar <NUM> in 3D view. The side section <NUM> is formed as a u-shaped bend, where the upper part <NUM> is integrally connected to the frame front <NUM>. The side section <NUM> comprises a notch <NUM> and a connection hole <NUM>. The connection hole is oblong and comprise a near end <NUM>, which is the end closest to the notch <NUM>, and a remote end <NUM>, which is the end farthest away from the notch <NUM>. Between the notch <NUM> and the connection hole <NUM> is an intermediate part <NUM>. The side section <NUM> comprises an inner side <NUM>, which is the inner side of the u-shaped bend, and an outer side <NUM>, which is the outer side of the u-shaped bend. The connection hole <NUM> comprises an inside edge <NUM> at the inner side of the side section <NUM>, and an outside edge <NUM> at the outer side of the side section <NUM>. The notch <NUM> comprises an inside rim <NUM> (<FIG>) at the inner side <NUM> of the side section <NUM>, and an outside rim <NUM> at the outer side <NUM> of the side section <NUM>.

The upper end <NUM> of the side bar <NUM> comprises a longitudinal axial grove <NUM> cut into the side bar <NUM> from the top end <NUM> of the side bar <NUM>. The axial groove divides the upper end <NUM> of the side bar <NUM> in an outside elastic part <NUM> and an inside elastic part <NUM>. The outside elastic part and the inside elastic part functions as blade springs. When the outside elastic part <NUM> and the inside elastic part <NUM> are pushed away from each other, they generates a spring force pressuring the two elastic parts <NUM>, <NUM> toward the axial groove <NUM> and toward each other. The outside elastic part <NUM> comprises a connection hook <NUM> at the top end <NUM> and the connection hook <NUM> comprises a topside <NUM>, which is identically to the top end <NUM>, and an underside <NUM>.

<FIG> illustrates the side bar <NUM> attached to the side section <NUM>. The inside elastic part <NUM> is engaging the notch <NUM> and the outside elastic part <NUM> is going through the connection hole <NUM> and is engaging the near end <NUM> and the remote end <NUM> of the connection hole. The intermediate part <NUM> is now between the outside elastic part <NUM> and the inside elastic part <NUM> pushing the inside elastic part <NUM> and the outside elastic part <NUM> away from each other, therefore, a spring force between the outside elastic part and the inside elastic part towards the axial groove <NUM> is generated, making the inside elastic part and the outside elastic part pinching the intermediate part <NUM> between them.

<FIG> illustrates the side section <NUM> of the frame front and the upper part <NUM> of the side bar in a side view and a 3D view respectively. The outside elastic part <NUM> comprises a connection hook <NUM> at the top end <NUM>. The inside elastic part <NUM> comprises, described from the top end, a locking hook <NUM>, a constriction <NUM>, a slanting part <NUM>, a chin <NUM> and a straight part <NUM>.

<FIG>, <FIG> illustrates the side section <NUM> and the upper part <NUM> of the side bar <NUM> in an open position, an intermediate position and a closed position respectively.

<FIG> shows the open position in a side view and <FIG> shows the open position in a 3D view. The connection hook <NUM> is going through the connection hole <NUM> and the outside elastic part <NUM> is engaging the connection hole <NUM> and wedging into the near end <NUM> of the connection hole and is engaging the remote end <NUM> of the connection hole. The connection hook <NUM> is a part of the outside elastic part <NUM>. It may be the connection hook <NUM>, which is engaging the near end <NUM> and the remote end <NUM> of the connection hole with the topside <NUM> engaging the remote end <NUM> and the underside <NUM> engaging the near end <NUM>. The inside elastic part <NUM> is engaging the notch <NUM> and is wedging into the bottom of the notch <NUM>. In an open position it is the slanting part <NUM> of the inside elastic part, which is engaging the notch <NUM>. The intermediate part <NUM> of the side section <NUM> is pinched between the inside elastic part <NUM> and the outside elastic part <NUM>. The connection hook <NUM> is engaging the near end of the connection hole <NUM>, the connection hook may only engage the inside edge of the connection hole. The side bar <NUM> is fixed in a closed position by the connection hook engaging both the near end and the remote end of the connection hole. The side bar <NUM> is thereby not allowed to move so far out that the notch <NUM> reaches the end of the inside elastic part. At the end of the inside elastic part is the locking hook <NUM> preventing that in case the side bar is extended beyond the open position that the side bar would fall off the side section and the spectacles fall apart.

<FIG> shows, in a side view and a 3D view respectively, the side section <NUM> and the upper part <NUM> of the side bar <NUM> in an intermediate position between the open position and the closed position. Compared to the open position in <FIG>, the side bar is now moved inward, the connection hook <NUM> is still in the connection hole <NUM>, but the notch <NUM> has moved and is now in contact with the inside elastic part <NUM> close to the chin between the slanting part <NUM> and the straight part <NUM>.

If the notch <NUM> is positioned in a position engaging the slanting part <NUM>, the spring force generated by the outside elastic part <NUM> and the inside elastic part <NUM>, which is working as blade springs, will push the side bar <NUM> back into an open position. The movement to an open position will stop when the top end of the outside elastic part hits the remote end <NUM> of the connection hole. If the notch is positioned in a position engaging the straight part <NUM> of the inside elastic part <NUM>, the spring force will push the side bar <NUM> into a closed position. The movement will stop when the top end of the outside elastic part hits the inner side <NUM> of the side section <NUM> by hitting the inside edge <NUM> of the remote end <NUM> of the connection hole.

<FIG> shows, in a side view and a 3D view respectively, the upper part <NUM> of the side bar <NUM> in a closed position. Now the notch <NUM> is engaging the straight part <NUM> of the inside elastic part <NUM> and is wedging into the bottom <NUM> of the notch <NUM>. The outside elastic part <NUM> is engaging the connection hole <NUM> and is wedging into the near end <NUM> of the connection hole. The connection hook <NUM> is still at least partly passing through the connection hole <NUM>. The top end of the outside elastic part, which also is the topside <NUM> of the connection hook, is engaging the inner side <NUM> of the side section <NUM>, possible by engaging the inside edge <NUM> of the remote end of connection hole <NUM>, and also engaging the near end <NUM> keeping the side bar <NUM> in a closed position.

<FIG> shows the side section <NUM> with a slit <NUM> between the notch <NUM> and the connection hole <NUM>. The thickness of the slit <NUM> is smaller than the general thickness of the side section <NUM>. For instance the side section may have a general thickness of <NUM>, whereas the slit may have a thickness of <NUM>. The surface of the slit is preferable parallel to the surface of the side section <NUM>.

When the notch <NUM>, which is located at the end of the side section <NUM>, is engaging the inside elastic part <NUM> above the chin <NUM>, on the slanting part <NUM>, the spring force will push the side bar <NUM> towards an open position. When the notch <NUM> is engaging the inside elastic part <NUM> below the chin <NUM>, on the straight part <NUM>, the spring force will push the side bar <NUM> towards a closed position.

However, when the chin <NUM> of the inside elastic part <NUM> is engaging the notch <NUM>, at or near the bottom <NUM> of the notch, the side bar may stand still and not move neither to an open nor to a closed position. Therefore, it is preferable that the thickness of the notch is reduced, where the notch engages the inside elastic part <NUM>. To achieve this in <FIG> a slit <NUM> is cut in the intermediate part <NUM> between the notch <NUM> and the connection hole <NUM>. The slit <NUM> is preferable cut in the outer side <NUM> of the side section <NUM>, but it may alternatively be cut in the inner side <NUM> of the side section.

When the chin <NUM> passes the outside rim <NUM> between the notch <NUM> and the slit <NUM>, then the notch engages the straight part <NUM>, and the side bar <NUM> will move towards a closed position. When the chin passes the inside rim <NUM> between the notch and the inner side <NUM> of the side section <NUM>, then the notch engages the slanting part and the side bar <NUM> will move towards an open position.

When the side section <NUM> is relatively thick, it is preferable to reduce the thickness of the notch <NUM> in the area, where the notch engages the inside elastic part <NUM>. This may be achieved by cutting a slit <NUM> in the intermediate part <NUM> between the connection hole <NUM> and the notch <NUM> to reduce the thickness of the side section at the notch <NUM> and thereby reducing the thickness of the notch <NUM>. Thereby, the area, where the movement of the side bar may be standing still, is reduced.

<FIG> shows the side section <NUM> with a slit <NUM> in the intermediate part <NUM> between the notch <NUM> and the connection hole <NUM>, where the end of the slit <NUM>, at the notch <NUM>, has a section <NUM>, which has a slope <NUM>, sloping towards the notch <NUM>.

The slope <NUM> has the advantage of further reducing the thickness of the notch <NUM> at the area, where the inside elastic part <NUM> engages the notch, and therefore reduces the area, where the movement of the sidebar may be standing still, when the notch <NUM> engages the chin <NUM>. When the chin passes the outside rim <NUM> between the notch <NUM> and the slope <NUM> towards the slope, then the notch engages the straight part <NUM>, and the side bar <NUM> will move towards a closed position.

The slope <NUM> and the slit in <FIG> is on the outer side <NUM> of the side section <NUM>, but may alternatively be made on the inner side <NUM>.

The slope <NUM> can be combined with a slit <NUM> as shown in <FIG>, but an embodiment without a slit <NUM>, but with a slope <NUM> is also possible. <FIG> shows the side section <NUM> with a slit <NUM> in the intermediate part <NUM> between the notch <NUM> and the connection hole <NUM>. <FIG> shows an alternative embodiment of the notch, where the notch <NUM> does not narrow towards the bottom <NUM> of the notch, instead the bottom of the notch is flat.

<FIG> shows the side section <NUM> with a slit <NUM> in the intermediate part <NUM> between the notch <NUM> and the connection hole <NUM>. <FIG> shows the slope <NUM> at the end of the slit closest to the notch. Further, also in <FIG> the notch <NUM> does not narrow towards the bottom <NUM> of the notch, instead the bottom is flat.

Not having the notch narrowing towards the bottom makes the manufacturing simpler, and the narrowing may not be needed, if the width of the inside elastic part of the side bars is almost the same as the width of the notch.

Also, the near end and the remote end of the connection hole may in an alternative embodiment be flat, even though this is now shown in any of the figures.

The slope and the slid in <FIG> are shown on the outer side <NUM> of the side section, but may alternatively be placed in the inner side <NUM>. In a further embodiment there may be a slits and/or slopes on both sides of the side section.

Claim 1:
A hinge mechanism for spectacles comprising a frame front and two side bars, the frame front (<NUM>) comprises two side sections (<NUM>) for attaching the side bars (<NUM>) to the frame front, each side section being in the form of a bent metal plate and each side section comprising a connection hole (<NUM>) and a notch (<NUM>), and each side bar (<NUM>) comprises an axial groove (<NUM>), the axial groove divides an upper end (<NUM>) of the side bar in an outside elastic part (<NUM>) and an inside elastic part (<NUM>),
- the outside elastic part and the inside elastic part both generate a spring force working towards the axial groove (<NUM>),
- the outside elastic part (<NUM>) of the side bar is engaging the connection hole (<NUM>) of the side section (<NUM>), and
- the inside elastic part (<NUM>) of the side bar is engaging the notch (<NUM>) of the side section (<NUM>),
- the spring force of the outside elastic part (<NUM>) is pressuring the outside elastic part against the side of the connection hole (<NUM>), and
- the spring force of the inside elastic part (<NUM>) is pressuring the inside elastic part against the notch (<NUM>),
- the outside elastic part (<NUM>) comprises a connection hook (<NUM>), and the connection hook (<NUM>) is engaging the connection hole in the side section, preventing the outside elastic part (<NUM>) from sliding out of the connection hole (<NUM>).