A self-closing hinge has a housing shaft section with a bore extending therethrough in a direction substantially parallel to a longitudinal axis is attachable to a first rotatable member. A bore extends through the housing shaft section. The cross-sectional profile of the bore in a plane orthogonal to the longitudinal axis has at least one arcuate portion and at least one non-arcuate portion. A roll pin rotatably disposed in the bore has substantially the same cross-sectional profile as the bore. A pair of shaft members, each having a shaft-member body attachable to a second rotatable member, has a pin inserted in an interference fit in the opposed ends of the roll-pin bore. The pins have a cross-sectional profile corresponding to the roll-pin cross-sectional profile.

BACKGROUND OF THE INVENTION

The present invention relates to a self-closing hinge, particularly to a spring-less structure that accomplishes automatic closing with small angle movement.

Many electronic products available in the market today, such as laptops, mobile phones, translation machines, PDAs (personal digital assistants) and the like; generally have a main body and a screen or lid that can be hinged or rotated by a certain angle relative to the main body. Traditional mechanical hinges require the user to manually open and close the device through the full range of motion. Other hinges have attempted to provide for automatic closing of screens or lids through use of torsion springs which resist the opening of the hinge and force the door shut. However, such springs have a limited lifetime and operate over the entire range of angular movement, thereby prohibiting the screen or lid from remaining open at a fixed location.

Accordingly, there is a need for an improved hinge structure which overcomes the aforementioned shortcomings in the prior art by providing automatic closing of the screen or lid at small angles while still allowing the hinge to remain open at discrete angles therebetween.

BRIEF SUMMARY OF THE INVENTION

Briefly stated, one embodiment of the present invention is directed to a self-closing hinge for pivotably connecting a first rotatable member to a second rotatable member. The self-closing hinge has a housing comprising a housing shaft section having a longitudinal axis. The housing shaft section is attachable to the first rotatable member. A housing shaft-section bore extends through the housing shaft section in a direction substantially parallel to the longitudinal axis. The housing shaft-section bore has a housing shaft-section bore cross-sectional profile in a plane orthogonal to the longitudinal axis. The housing shaft-section bore cross-sectional profile has at least one arcuate housing shaft-section bore portion and at least one non-arcuate housing shaft-section bore portion. A roll pin is rotatably disposed in the housing shaft-section bore. The roll pin has a roll-pin bore extending through the roll pin in the direction substantially parallel to the longitudinal axis. The roll pin has a roll-pin cross-sectional profile in the plane orthogonal to the longitudinal axis. The roll-pin cross-sectional profile has at least one arcuate roll-pin portion and at least one non-arcuate roll-pin portion. A pair of shaft members is provided. Each shaft member of the pair of shaft members has a shaft-member body attachable to the second rotatable member. A shaft-member pin extends from the shaft-member body and has a shaft-member pin cross-sectional profile corresponding to the roll-pin cross-sectional profile. The shaft member pin of one shaft member of the pair of shaft members is inserted in an interference fit in a first end of the roll-pin bore and the shaft member pin of the other shaft member of the pair of shaft members is inserted in an interference fit in a second end of the roll-pin bore.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to an embodiment of the invention, examples of which are illustrated in the accompanying drawings. The terminology used in the description of the invention herein is for the purpose of describing the particular embodiment only and is not intended to be limiting of the invention.

The words “right,” left,” “lower,” “upper,” “front” and “rear” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the hinge, and designated parts thereof. The terminology includes the words noted above, derivatives thereof and words of similar import.

Although the words first, second, etc., are used herein to describe various elements, these elements should not be limited by these words. These words are only used to distinguish one element from another. For example, a first rotatable member could be termed a second rotatable member without departing from the scope of the present invention.

Referring to the drawings in detail, where like numerals indicate like elements throughout, there is shown inFIGS. 1-6a first preferred embodiment of a self-closing hinge, generally designated10, and hereinafter referred to as the “hinge”10in accordance with the present invention. The hinge10may be used to pivotably connect a first rotatable member810to a second rotatable member800rotatable relative to the first rotatable member810.

The hinge10comprises a housing12, a roll pin14, and a pair of shaft members16. The housing12comprises a housing shaft section18and a housing support section20fixedly attached to or integral with the housing shaft section18. Preferably, the housing shaft section18may be generally cylindrical in shape though it will be understood that any shape that facilitates rotation about a longitudinal axis24could be used. In a preferred embodiment, the housing support section20and the housing shaft section18may be integrally formed as one part. The housing support section20may be configured to be attached to the first rotatable member810, such as a lid, door, screen810or the like, for which the hinge10acts as a pivot. The housing support section20is attached or otherwise secured to the first rotatable member810by screws, bolts, an adhesive, nails, or the like which are well known in the art or, alternatively, the housing support section20may be integrally formed with the first rotatable member810.

The housing shaft section18further comprises a housing-shaft-section bore22extending through the housing shaft section18in the direction of the longitudinal axis24and substantially parallel therewith. The housing shaft-section bore22has a housing shaft-section bore cross-sectional profile23in a plane orthogonal to the longitudinal axis24. In some embodiments, the housing shaft-section bore cross-sectional profile23may have at least one arcuate housing shaft-section bore portion23aand at least one non-arcuate housing shaft-section bore portion23b. In other embodiments, the housing shaft-section bore cross-sectional profile23may be D-shaped. Alternatively, the housing shaft-section bore cross-sectional profile23may be circular or any other suitable shape. The housing12is preferably made of a metallic material, but could be made from a polymeric or any other suitable material known in the art.

The roll pin14is configured to be slidably inserted into the housing-shaft-section bore22, as can be seen inFIG. 4, such that roll pin14is completely disposed in the housing-shaft-section bore22. The roll pin14further comprises a roll-pin cross-sectional profile26, lying in a plane orthogonal to the longitudinal axis24, which is comprised of at least one roll-pin cross-sectional profile arcuate portion28and at least one roll-pin cross-sectional profile non-arcuate portion30(seeFIG. 3). An outer dimension of the roll pin14is at least slightly smaller than an inner dimension of the housing-shaft-section bore22. In a preferred embodiment, the roll-pin profile26is also preferably D-shaped. The roll pin14further includes a roll-pin slit31(seeFIG. 3), extending along the entire length substantially parallel to the longitudinal axis24. The roll-pin slit31is disposed in the arcuate portion28of the roll-pin profile26, generally opposite of the non-arcuate portion30. The roll-pin slit31facilitates expansion of the roll pin14when the shaft members16are inserted, as discussed in more detail below. The roll pin14further comprises a roll-pin bore32(seeFIG. 3) extending throughout the length of the roll pin14in the direction of the longitudinal axis24and substantially parallel therewith. The roll pin14also comprises a pair of roll-pin slots34cut into the arcuate portion28of the roll-pin profile26orthogonal to the longitudinal axis24and at predetermined lengths along the roll pin14. The roll-pin slots34extend at least partially from the top of the roll pin14toward the bottom. The roll-pin slots34define three distinct contiguous regions36a,36b,36con the roll pin14. In a preferred embodiment, the distinct region36bof the roll pin14may be crimped in the housing-shaft-section bore22. When the roll pin14is fully inserted into the housing-shaft-section bore22, the housing shaft section18of the housing12may be crimped utilizing a crimping or clamping tool which engages the housing12. The crimping of the roll pin14translationally and rotationally secures the roll pin14into the housing-shaft-section bore22. In an alternative embodiment, the housing12may include an indent (not shown) on the housing shaft section18. The indent facilitates crimping of the roll pin14within the housing-shaft-section bore22.

The hinge10further comprises a pair of shaft members16. Each shaft member16comprises a shaft-member pin40and a shaft-member body42. The shaft-member pin40extends outwardly away from the shaft-member body42in a direction parallel with the longitudinal axis24. The shaft-member pin40further has a profile that matches the roll-pin profile26, with an outer dimension of the shaft-member pin40being at least slightly larger than an inner dimension of the roll pin14, such that, when assembled together, the shaft member16and roll pin14are in an interference fit. The shaft-member pin40is configured to be slidably inserted into the roll-pin bore32of the roll pin14. The shaft-member pin40extends inwardly from the end of the roll pin14a distance slightly less than an outer edge of the roll-pin slots34(seeFIG. 6). When the shaft-member pin40of the shaft member16is inserted into the roll-pin bore32of the roll pin14, the roll-pin slit31of the roll pin14allows the roll pin14to accommodate the larger dimension of the shaft-member pin40.

The shaft-member body42of the shaft member16includes a shaft-member-body mating surface48which engages a sidewall18A of the housing shaft section18of the housing12when the shaft-member pin40is fully inserted into the roll pin14, as illustrated byFIG. 4. The shaft-member body42further comprises an shaft-member body attachment section46which lies in a plane generally orthogonal to the shaft-member-body mating surface48and extends in a direction opposite that of the shaft-member pin40. The shaft-member body attachment section46further comprises one or more holes50, and preferably one, extending completely through the shaft-member body attachment section46. The holes50are configured to receive screws, nails, pins, bolts, fasteners or the like, as is well known in the art, for affixing the hinge10to a surface of a base800. The pair of shaft members16is preferably made of a metallic material, but could be made from any suitable material known in the art.

The housing12and roll pin14are capable of rotating about the shaft pins16at a rotation angle β. As rotation angle β approaches small angles relative to horizontal, the roll-pin profile26allows for a “snapping” function to occur, namely the friction and torque caused by rotation of the housing12and roll pin14relative to the shaft member16forces the hinge closed. The “snapping” function occurs when the rotation angle β ranges from about zero degrees to about fifteen degrees, namely when the bottom of the shaft pin16approaches the non-arcuate portion30of the roll pin14.

The hinge10is assembled by inserting the roll pin14into the shaft section18of the housing12and then crimping the housing12and roll pin14together at distinct region36b. The shaft members16are then inserted into each end of the roll pin14, such that each mating surface48is in contact with the sidewall18aof the shaft section18.

In operation, the self-closing hinge10is attached to the second rotatable member (or base)800of an electronic product utilizing conventional attachment means engaged through the holes50of the shaft members16. The housing support section20is also attached to, or integral with, the first rotatable member (or screen or lid)810of the electronic product utilizing conventional attachment means. The user of the electronic product may then open the screen810and utilize the device within the base800. The friction and torque provided by the interference fit of the roll pin14and shaft member16allows the screen810to be held open at the rotation angle β the user chooses, which causes stress in the roll pin14due to mismatch of the geometries between the roll pin14and the shaft members16. When the user is finished with the electronic product, the user rotates screen810toward the closed position (i.e. when rotation angle β is about 0 degrees). When the rotation angle β is about fifteen degrees from horizontal, the screen810automatically snaps shut as the roll pin14biases towards a relaxed state. The friction and torque provided by the hinge10maintains the screen810in a closed position until the user manually opens the screen810again.

The foregoing detailed description of the invention has been disclosed with reference to specific embodiments. However, the disclosure is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Those skilled in the art will appreciate that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. Therefore, the disclosure is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.

All references, patent applications, and patents mentioned above are incorporated herein by reference in their entirety and are not to be construed as an admission that any of the cited documents constitutes prior art, or as an admission against interest in any manner.