Automatic locking hinge

Abstract

The invention relates to an automatic locking hinge (1, 30, 35, 41) comprising a first hinge leaf (2, 31, 36, 41) and a second hinge leaf (3, 32, 37) pivotally moveable with respect to each other about a hinge pin (8), the first hinge leaf (2, 31, 36, 41) including a slot (9) comprising first and second slot side walls (10, 11) and first and second slot ends (12, 13) in which slot (9) the hinge pin (8) is located such that the hinge pin (8) may slidably move within the slot (9) against a resilient spring means (7) which bias the hinge pin (8) against the second slot end (13). The second hinge leaf (3 32, 37) includes second locking part (4) and a window (18) defined by first and second sides (19, 20), supporting the hinge pin (8), and the slot (9) and hinge pin (8) are dimensioned such that, in a locked position, the second locking part (4) interlocks with a first locking part (23) such that the spring means (7) acts to hold them together to hold the hinge (1) in the locked position, and is releasable to an unlocked position by relative movement of the first and second hinge leaves against the spring means (7).

Description

AUTOMATIC LOCKING HINGE

[0001] The present invention relates to a hinge mechanism comprising two leaves that automatically lock in both directions relative to each other when in an unfolded position and to a device, such as a pair of foldable spectacles, incorporating said hinge.

[0002] Hinges that require their leaves to lock relative to each other typically rely on additional mechanical components to achieve this function. While some existing hinge designs incorporate an automatic locking feature, these mechanisms often suffer from insufficient locking strength, causing the hinge to unintentionally revert to the folded position. Over time, such hinges may also experience wear, further reducing their effectiveness in maintaining a stable locked state.

[0003] One specific application of such hinges is in foldable spectacles, where a hinge mechanism in the nose bridge allows the lenses to fold inward for compact storage and protection by the sidepieces when not in use. Examples of such foldable spectacle designs are disclosed inEP 2 904 448 B1andWO 2010 / 022900 A1, which describe folding mechanisms integrated into the nose bridge to enable compact folding of the eyewear. However, the hinges in these known designs exhibit inadequate locking strength and tend to wear out over time, failing to maintain a reliably locked position. This compromises the usability and durability of the spectacles, necessitating a more robust and long-lasting locking mechanism.SUMMARY OF THE INVENTION

[0004] The present invention relates to a hinge mechanism designed to automatically lock in an unfolded position, as defined in the appended claims.

[0005] The invention ensures a secure and stable operation without the need for additional locking components. This hinge consists of two leaves that engage in a self-locking manner when fully extended, preventing unintended folding or collapse. The locking mechanism is integrated within the hinge structure, eliminating the need for external latches, springs, or other auxiliary locking elements, thereby enhancing durability, reliability, and ease of manufacturing.

[0006] This invention is applicable across various general hinge-based applications where reliable locking is required. One key implementation is as a nose bridge hinge for foldable spectacles, where the mechanism ensures that the eyewear remains securely unfolded during use while allowing smooth and controlled folding for compact storage. Unlike conventional foldable spectacle hinges, which often suffer from insufficient locking strength, mechanical wear, and unintended loosening over time, the proposed hinge offers a more robust, long-lasting, and wear-resistant solution. The improved locking mechanism ensures that the spectacles stay securely in place during use while maintaining a compact, lightweight, and aesthetically seamless design.

[0007] Beyond its application in foldable eyewear, the self-locking hinge is highly versatile and can be implemented in a wide range of collapsible and foldable structures where a dependable locking mechanism is essential. Examples include portable electronic devices, medical instruments, foldable furniture, automotive components, and industrial enclosures. The compact nature of the hinge makes it particularly beneficial for space-saving applications, while its enhanced durability ensures long-term performance even under frequent folding and unfolding cycles.

[0008] Additionally, the hinge mechanism can be manufactured using various materials, including metals, high-strength polymers, and composite materials, allowing it to be adapted for different industries and performance requirements. Its simple yet effective design reduces the complexity of assembly, minimizes maintenance needs, and provides a cost-effective solution for manufacturers seeking a reliable, built-in locking hinge for their products.

[0009] The invention thus addresses the limitations of existing hinge mechanisms, providing a more secure, durable, and versatile solution that enhances both functionality and user experience across a wide range of applications.

[0010] The operation of the hinge, including folding and unfolding, does not require any additional components such as handles or levers. This feature makes the hinge particularly suitable for applications demanding secure and stable positioning, such as nose bridge mechanisms for foldable eyewear. In the case of foldable spectacles, it is especially important that no small handles or similar external elements are needed for operation, ensuring a seamless and user-friendly design. Beyond eyewear applications, the hinge may also be employed in various other fields where a self-locking mechanism is advantageous.DETAILED DESCRIPTION

[0011] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0012] Reference is made to the appended drawings, wherein:

[0013] is an isometric view of a first embodiment of a hinge of the invention in a unfolded state,

[0014] shows a top view with a portion of the first hinge leaf removed,

[0015] shows a top view of the hinge of,

[0016] is a longitudinal side cross section the hinge ofalong the line AA ofin an unfolded state,

[0017] is an isometric view of the hinge ofwith the second hinge leaf shown separated in two parts,

[0018] is a longitudinal side cross section ofshowing an initial folding stage,

[0019] shows a top view with the first hinge leaf removed of, in the initial folding stage shown in,

[0020] shows a top view of the hinge ofin a folded state,

[0021] is a is a longitudinal side cross section along the line BB of the hinge ofin an folded state.

[0022] shows a top view with the first hinge leaf partially removed of, in the folded state,

[0023] is a perspective view of a second embodiment of a hinge of the invention in a unfolded state with the second hinge leaf shown separated to show the internal components,

[0024] is a top plan view of the hinge ofin a unfolded state,

[0025] is a side cross section view along the line CC ofof the hinge of, in an unfolded state.

[0026] is a perspective view of a third embodiment of a hinge of the invention in a unfolded state with the second hinge leaf shown separated to show the internal components,

[0027] is a top plan view of the hinge ofin a unfolded state,

[0028] is a side cross section view along the line DD ofof the hinge of, in an unfolded state,

[0029] is a perspective view of a fourth embodiment of a hinge of the invention in a unfolded state with the second hinge leaf shown separated to show the internal components, and

[0030] is a perspective view of a pair of spectacles using a hinge of the invention.DETAILED DESCRIPTION OF EMBODIMENTS

[0031] illustrates a hinge 1 in a position referred to as an unfolded state. This position will be referred to as unfolded, whileillustrates the hinge in its folded state.

[0032] toillustrate a first embodiment of an automatic locking hinge 1 according to the invention comprising a first hinge leaf 2 and a second hinge leaf 3 pivotally moveable with respect to each other about a hinge pin 8. The first hinge leaf 2 includes a slot 9 defined by first and second slot side walls 10, 11 and first and second slot ends 12, 13 in which the hinge pin 8 is located such that the hinge pin 8 may slidably move within the slot 9 against a resilient spring means 7 which bias the hinge pin 8 against the second slot end 13. In this first embodiment the spring means is a butterfly leaf spring 7 and the first slot end 12 is defined by a shaft 5 which anchors the butterfly leaf spring 7. The second slot end 13 is in the form of a wall which forms a stop to the travel of the hinge pin 8. The second hinge leaf 3 includes a second locking part 4 and a window 18 defined by first and second sides 19, 20, and the hinge pin 8 is supported at each end 14, 15 in sockets in the corresponding first and second sides 19, 20.

[0033] The slot 9 and hinge pin 8 are dimensioned such that, in a locked position, the first locking part 4 interlocks with a first locking part 23 of the first hinge leaf 2 such that the spring means 7 acts to hold the second locking part 4 and the first locking part 23 together to hold the hinge 1 in the locked position, and is releasable to an unlocked position by a lateral pushing action against the spring means 7. The first and second hinge leaves are pushed together laterally in the plane of the hinge leaves by the user so that subsequent rotation of the hinge leaves by the user causes the locking parts 4, 23 to disengage.

[0034] As best shown in Fig, 1a, the spring means 7 is separate butterfly leaf spring with two symmetrical wings which act against the hinge pin 8 and is secured at its centre in the slot 9 by a shaft 5 so that the hinge pin 8 of the second hinge leaf 3 and slot 9 of the first hinge leaf 2 are held together.

[0035] Alternative spring means could be used, for example a leaf spring attached at the first slot end 12, or to the hinge pin 8, or an elastomeric pad at the first slot end 12 or forming part of the hinge pin 8. Other forms of spring can be envisaged by the skilled person.

[0036] In this embodiment, as can be seen best inandthesecond locking part 4 is a bar shaped and locates in the first locking part 23 which is in the form of a recess which is formed by the slot end 12 of the slot 9 which in this embodiment is defined by the hinge pin 8 and butterfly spring 7 and an intermediate section 26. The intermediate section 26 is formed as an inclined portion of the first hinge leaf 2 where it is dog-legged with a main part 22 spaced from the second slot side wall 11.

[0037] The intermediate section 26 is sloped to form an angled guiding surface 6 which serves as one side of the recess of the first locking part 23 to guide the second locking part 4 into the unfolded position, under the action of the spring means 7. The first slot side wall 10 extends beyond the first slot end 12 to form an extension 25 such that the second locking part 4 rests under the extension 25 in the locked position, and is urged to remain there by the springe means 7.

[0038] The extension 25 has an inclined surface 27 which also guides the second locking part 4 into the first locking part recess 23. Thus when the user wishes to close the hinge 1 the hinge leaves 2, 3 are rotated in a counterclockwise direction as viewed infor example, so that the locking part 4 compresses the spring 7 as it is guided by the inclined surface 27 until it clicks into place in the locked position with the locking bar 4 underneath the extension 25.

[0039] shows the hinge lock in the position of just being released from the unfolded state, or about to be locked back into the unfolded state. When the hinge 1 lock is to be unlocked, the second hinge leaf 3 is moved towards the first hinge leaf 2, so they are in effect moved together by a user, but for the purposes of explanation the second hinge leaf is moved from right to left in, thus compressing the spring means 7 and moving the hinge pin 8 so that the second locking part 4 is moved beyond the extension 25 and the hinge 1 may be opened may be rotating the second hinge leaf 3 with respect to the first hinge leaf 2 about the hinge pin 8, so that the second locking part 4 moves out of the first locking part recess 23.

[0040] Correspondingly when the hinge 1 is desired to be closed the second hinge part 3 is rotated with the respect to the first hinge part 2, in a counter clockwise direction in, the second locking part 4 engages the sloping surface 27 of the extension 25 which causes the hinge pin 8 to move to the left inallowing the second locking part 4 to move past the extension 25 and come to rest in the first locking part recess 23 back to the hinge locked position.

[0041] shows the hinge 1 in the completely folded position with the second hinge leaf 3 having been rotated clockwise as shown by the arrow so that the second hinge leaf 3 is adjacent to the first hinge leaf 2.

[0042] Reference is now made to,andwhich show an alternative embodiment of the hinge of the invention with corresponding components shown having the same identifying numerals. In this embodiment the hinge 30 comprises a first hinge leaf 31 and a second hinge leaf 32 which is shown in two separated halves infor the purposes of seeing the internal components. The first hinge leaf 31 is configured differently in that its first locking part 23, which although is still in the form of a recess, is arranged between the slot 9 and an inner end 24. In other ways the hinge lock 30 operates in the same way as in the first embodiment. The spring means 7 is located in the slot 9 and is shown as a butterfly spring, but could also be a leaf spring or an elastomeric pad. The spring 7 acts to keeps the second locking part 4 in the recess 23 underneath the extension 25, so that pushing of the first and second hinge leaves 31, 32 together causes the second locking part 4 to move out from underneath the extension 25 so that the first and second hinge leaves 31, 32 may be rotated with respect to each other.

[0043] In this second embodiment, as in the first embodiment, the spring means 7 acts to urge the pin 8 towards the free end 24 and the angled guiding surface 6 is correspondingly angled so that the act of pushing together the first hinge leaf 31 and the second hinge leaf 32 unlocks the hinge 30 and enables the first and second leaf hinges 31, 32 to be pivoted with respect to each other.

[0044] Reference is now made toandand 9a which show a further third alternative embodiment of the hinge of the invention with corresponding components shown having the same identifying numerals. In this embodiment the hinge 35 comprises a first hinge leaf 36 and a second hinge leaf 37 which is shown in two separated halves infor the purposes of seeing the internal components. The first hinge leaf 36 is configured differently in that its first locking part 23 is formed as a groove 33 with an extending tongue 40 at the free end 24 of the first hinge leaf 36 and the second locking part 37 has a correspondingly dimensioned portion 34 which engages in the groove 33 of the first locking part 23.

[0045] In this third embodiment the spring means 7 acts to urge the pin 8 away from the free end 24 and the angled guiding surface 6 is correspondingly angled so that the act of pulling apart the first hinge leaf 36 and the second hinge leaf 37, unlocks the hinge 35 and enables the first and second leaf hinges 36, 37 to be pivoted with respect to each other.

[0046] Reference is now made towhich shows a further fourth alternative embodiment of the hinge of the invention with corresponding components shown having the same identifying numerals. In this embodiment the hinge 41 comprises a first hinge leaf 42 and a second hinge leaf 32 which is shown in two separated halves infor the purposes of seeing the internal components. The first hinge leaf 42 is configured differently in that its first locking part 23 is formed as a groove 33 with an extending tongue located remotely from the free end 24 of the first hinge leaf 36 and slot 9 is located proximal to the free end 24. The second locking part 23 is in the form of a locking bar 4 as in the first and second embodiments.

[0047] Reference is now made toin which a pair of spectacles 38 is shown having a pair of lens frames 28, 29. The first and second hinge leaves 2, 3 are attached to the corresponding lenses frames 28, 29 forming a hinged nose bridge 1, 30, 35 so the spectacles 21 may be foldable about the nose bridge 1, 30, 35.

[0048] In a known manner the spectacles 21 comprise a pair of hinged arms 38 so the pair of spectacles as a while can be folded into a small volume and stowed in a smaller space.

[0049] Therefore, the main purpose of the invention is to provide an automatic locking hinge

[0050] as defined by the appended claims.

[0051] The above-described embodiments are merely preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto.

[0052] Those skilled in the art will readily observe that numerous modifications and alterations of the apparatus of the invention may be made while retaining the teachings and benefits of the invention.Component List

[0053] Locking HingeFirst hinge leafSecond hinge leafSecond locking partShaftGuiding surfaceSpring meansHinge PinSlotFirst slot side wallSecond slot side wallFirst slot endSecond slot endFirst pin endSecond pin endFirst pin socketSecond pin socketWindowFirst sideSecond sidePair of spectaclesMain partFirst locking partInner endExtensionIntermediate sectionInclined surfaceLens frameLens frameAutomatic lockable hingeFirst hinge leafSecond hinge leafGrooveDimensioned portionAutomatic locking hingeFirst hinge leafSecond hinge leafHinged arm

[0054] 40. Tongue

[0055] 41. Automatic locking hinge

[0056] 42. First hinge leaf

Claims

An automatic locking hinge 1, 30, 35, 41 comprising a first hinge leaf 2, 31, 36, 41 and a second hinge leaf 3, 32, 37 pivotally moveable with respect to each other about a hinge pin 8, the first hinge leaf 2, 31, 36, 41 including a slot 9 comprising first and second slot side walls 10, 11 and first and second slot ends 12, 13 in which slot 9 the hinge pin 8 is located such that the hinge pin 8 may slidably move within the slot 9 against a resilient spring means 7 which bias the hinge pin 8 against the second slot end 13, characterised in that the second hinge leaf 3 32, 37 includes second locking part 4 and a window 18 defined by first and second sides 19, 20, and the hinge pin 8 being supported between the first and second sides 19, 20, and that the slot 9 and hinge pin 8 are dimensioned such that, in a locked position, the second locking part 4 interlocks with a first locking part 23 of the first hinge leaf 2, 31, 36, 41 such that the spring means 7 acts to hold the second locking part 4 and the first locking part 23 together to hold the hinge 1 in the locked position, and is releasable to an unlocked position by relative movement of the first and second hinge leaves against the spring means 7.An automatic hinge lock according to claim 1, characterised in that the spring means 7 is separate butterfly spring secured in the slot 9 by a shaft 5.An automatic hinge lock according to claim 1, characterised in that the spring means 7 is a leaf spring attached at the first slot end 12.An automatic hinge lock according to claim 1, characterised in that the second locking part 4 is a bar shaped and the first locking part 23 is in the form of a recess.An automatic hinge lock according to claim 4, characterised in that an angled guiding surface 6 is formed in the first locking part 23 to guide the second locking part 4 into the first locking part 23.An automatic hinge lock according to claim 5, characterised in that the first hinge leaf 2, 31, 36, 41 is dog-legged with a main part 22 spaced from the second slot wall 11 by an intermediate section 26 to form the recess of the first locking part 23.An automatic hinge lock according to claim 6, characterised in that, the intermediate section 26 is sloped from the main part 22 to the second slot side wall 11 to provide the guiding surface 6 to assist in guiding the second locking part 4 into the first locking recess 23.An automatic hinge lock according to claim 1, characterised in that the first slot side wall 10 extends beyond the first slot end 12 to form an extension 25 such that the second locking part 4 rests under the extension 25 in the locked position.An automatic hinge lock according to claim 8, characterised in that the extension 25 has an inclined surface 27 which guides the second locking part 4 into the first locking part 23.An automatic hinge lock according to claim 1, characterised in that the first hinge leaf 31, 36 comprises a inner end 24 and the first locking part 23 is arranged between the slot 9 and the inner end 24.An automatic hinge lock according to claim 1, characterised in that the first locking part 23 is formed as a groove 33 at the free end 24 of the first hinge leaf 36 and the second locking part 34 is formed as a correspondingly dimensioned tongue which engages in the groove 33.An automatic hinge lock according to claim 1, characterised in that the spring means 7 acts to urge the pin 8 towards the free end 24 and the angled guiding surface 6 is correspondingly angled so that the act of pushing together the first hinge leaf 2, 31, and the second hinge leaf 3, 32 unlocks the hinge and enables the first and second leaf hinges 2, 31, 3, 32 to be pivoted with respect to each other.An automatic hinge lock according to claim 1, characterised in that the spring means 7 acts to urge the pin 8 away from the free end 24 and the angled guiding surface 6 is correspondingly angled so that the act of pulling apart the first hinge leaf 36, 42 and the second hinge leaf 37, unlocks the hinge and enables the first and second leaf hinges 36, 42 and 37 to be pivoted with respect to each other.An automatic hinge lock according to claim 1, the first and second hinge leaves 2, 31, 36, 42, 3, 32, 37 are formed as the corresponding lenses or lens frames 28, 29 of a pair of spectacles 21 forming a hinged nose bridge corresponding to the hinge 1, 30, 35, 41 so the spectacles 21 may be foldable about the hinged nose bridge.A pair of foldable spectacles 21 comprising a locking hinge 1, 30, 35, 41 at the nose bridge comprising a first hinge leaf 2, 31, 36, 42 and a second hinge leaf 3, 32, 37 in the form of corresponding lens or lens frames 28, 29, and pivotally moveable with respect to each other about a pin 8, the first hinge leaf 2, 31, 36, 42 including a slot 9 comprising first and second slot side walls 10, 11 and first and second slot ends 12, 13 in which slot 9 the hinge pin 8 is located such that the pin 8 may slidably move within the slot against a resilient spring means 7 which bias the pin 8 against the second slot end 13, characterised in that the second hinge leaf 3, 32, 37 includes a window 18 defined by first and second sides 19, 20 in which the hinge pin 8 is located and spaced from a second locking part 4, and that the slot 9 and hinge pin 8 are dimensioned such that, in a locked position, the second locking part 4 interlocks with a first locking part 23 of the first hinge leaf 2, 31, 36, 42 such that the spring means 7 acts to hold the second locking part 4 and the first locking part 23 together to hold the hinge in the locked position, and is releasable to an unlocked position by relative movement of the first and second hinge leaves action against the spring means 7.

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