US20120067914A1 - Self centering hinge design for concentric sealing of an enclosure - Google Patents

Abstract

A waterproof, clam-shell style enclosure including a first cover, a second cover that is hingedly coupled to the first cover to pivot about an axis of rotation between an open state and a closed state defining an enclosed interior region of the enclosure, a seal positioned to limit or prevent the passage of fluid into the enclosed interior region of the enclosure, and a hinge that is configured to accommodate translation of the second cover with respect to the first cover in two different, perpendicular directions upon pivoting the second cover to a closed state to achieve uniform compression of the seal along its circumference.

Description

TECHNICAL FIELD
• This invention generally relates to sealable hinged enclosures and, more specifically, to a self centering hinge design for concentric sealing of such enclosures.
BACKGROUND OF THE INVENTION
• Clamshell-style sealable enclosures are waterproof or weatherproof enclosures that are employed to safely store articles, such as electronics, batteries or phones, for example. Such enclosures may be more commonly referred to as dry boxes. One example of a clamshell style sealable enclosure is disclosed in U.S. Pat. No. 7,341,144 to Tajiri et al., which is incorporated by reference.
• Clamshell-style sealable enclosures generally include two covers that are rotatably connected together by a conventional fixed hinge. In use, upon mating the covers together, a seal that's positioned on one of the covers inhibits the introduction of water, air or other contaminants into the sealed interior of the enclosure. The fixed hinges of the enclosure are typically pinned or snapped together and rotate about a fixed axis.
• It is a goal of sealed enclosure design to achieve a uniform seal across the entire perimeter of the enclosure to inhibit the introduction of water, air or other contaminants into the interior of enclosure. Due to the structural limitations of a fixed hinge and the cumulative dimensional tolerances of an enclosure, however, the seal may not be uniformly compressed across the perimeter of the enclosure, which can result in decreased or total failure of the enclosure seal. Specifically, the portion of the seal that is closest to the hinge may be more compressed than the portion of the seal that is furthest from the hinge. The enclosure seal may be compromised if compression of the seal is too high in one region and/or too low in another region.
• While sealing arrangements that account for a fixed hinge design and cumulative dimensional tolerances are known, those sealing arrangements suffer from various drawbacks. For example, in a crush seal application, the crush seals are oversized to account for the dimensional tolerance accumulation, thereby increasing the weight of the enclosure. In certain applications, such as a night vision goggle battery pack, for example, additional weight is undesirable.
• In view of the foregoing, there is a continuing need to further develop and refine hinges for enclosures, in the interests of performance, weight, cost, and manufacturability.
SUMMARY OF THE INVENTION
• According to one aspect of the invention, a waterproof, clam-shell style enclosure comprises a first cover; a second cover that is hingedly coupled to the first cover to pivot about an axis of rotation between an open state and a closed state, wherein, in a closed state, the first cover and the second cover define an enclosed interior region of the enclosure for storing an object; a seal positioned on a sealing surface of either the first cover or the second cover, wherein the seal is positioned to inhibit the passage of fluid into the enclosed interior region of the enclosure in the closed state of the enclosure; and a hinge that is configured to accommodate translation of the second cover with respect to the first cover in two different, axially perpendicular directions upon pivoting the second cover to a closed state to achieve uniform compression of the seal along its circumference.
• According to another aspect of the invention, a waterproof, clam-shell style enclosure comprises a first cover; a second cover that is hingedly coupled to the first cover to pivot about an axis of rotation between an open state and a closed state, wherein, in a closed state, the first cover and the second cover define an enclosed interior region of the enclosure; a seal positioned on a sealing surface of either the first cover or the second cover, wherein the seal is positioned to limit or prevent the passage of fluid into the enclosed interior region of the enclosure in the closed state of the enclosure; a hinge including a knuckle extending from either the first cover or the second cover and a pin positioned within a recess formed in the knuckle, wherein the knuckle is configured to rotate about the pin; and a gap, having a pre-determined size, defined between an exterior surface of the pin and the recess of the knuckle, wherein, upon pivoting the second cover to the closed state, the gap accommodates translation of the second cover with respect to the first cover in a direction that is orthogonal to both the axis of rotation and the sealing surface to achieve uniform compression of the seal along its circumference.
• According to yet another aspect of the invention, a waterproof, clam-shell style enclosure comprises a first cover; a second cover that is hingedly coupled to the first cover to pivot about an axis of rotation between an open state and a closed state, wherein, in a closed state, the first cover and the second cover define an enclosed interior region of the enclosure; a seal positioned on a surface of either the first cover or the second cover, wherein the seal is positioned to inhibit the passage of fluid into the enclosed interior region of the enclosure in the closed state; and a gap, having a pre-determined size, defined between a hinge component of the first cover and a hinge component of the second cover, wherein, upon pivoting the second cover to the closed state, the gap accommodates translation of the second cover with respect to the first cover in a direction that is parallel to the axis of rotation to achieve uniform compression of the seal along its circumference.
• These and other aspects of the present invention will become clear from the detailed discussion below when taken into consideration with the drawings. It is to be understood that the following discussion is intended merely to illustrate the preferred embodiment of the present invention. However, the present invention is not limited to the illustrated embodiment, but is limited solely by the claims appended to this specification.
BRIEF DESCRIPTION OF THE FIGURES
• The invention is best understood from the following detailed description when read in connection with the accompanying drawing. It is emphasized that, according to common practice, the various features of the drawing are not to scale. Included in the drawing are the following figures:
• FIG. 1 depicts a perspective view of a clam-shell style enclosure that is rotated to an open position, according to one exemplary embodiment of the invention;
• FIG. 2 depicts a side view of the open enclosure ofFIG. 1;
• FIG. 3 depicts a cross-sectional view of the enclosure ofFIG. 1 illustrated in a closed position with batteries;
• FIG. 4 depicts a plan view of the enclosure ofFIG. 1;
• FIG. 5 depicts a cross-sectional view of the hinge of the enclosure ofFIG. 4 taken along the lines5-5;
• FIG. 6 depicts a detailed view of the hinge of the open enclosure ofFIG. 1; and
• FIGS. 7-10 depict the covers of the enclosure ofFIG. 1 in an unassembled state.
DETAILED DESCRIPTION OF THE INVENTION
• Referring generally to the figures, and according to one aspect of the invention, a waterproof, clam-shell style enclosure10 comprises afirst cover14; asecond cover12 that is hingedly coupled to thefirst cover14 to pivot about an axis of rotation ‘A’ between an open state and a closed state, wherein, in a closed state, thefirst cover14 and thesecond cover12 define an enclosed interior region of theenclosure10. Aseal24 is positioned on asealing surface23 of either thefirst cover14 or thesecond cover12, wherein theseal24 is positioned to inhibit the passage of fluid into the enclosed interior region of theenclosure10 in the closed state of theenclosure10. Ahinge16,18 is configured to accommodate translation of thesecond cover12 with respect to thefirst cover14 in the ‘X’ and ‘Y’ directions upon pivoting thesecond cover12 to a closed state to achieve uniform compression of theseal24 along its circumference. Uniform compression of theseal24 along its circumference inhibits the escape of thermal energy in the form of heat from the sealed interior ofenclosure10 as well as the introduction of fluid or other contaminants into the sealed interior ofenclosure10.
• According to another aspect of the invention, thehinge16,18 of theenclosure10 includes aknuckle34 and apin30 positioned within arecess36 formed in theknuckle34, wherein theknuckle34 is configured to rotate about thepin30. A gap G2, having a pre-determined size, is defined between an exterior surface of thepin30 and therecess36 of theknuckle34, wherein, upon pivoting thesecond cover12 to the closed state, the gap G2 accommodates translation of thesecond cover12 with respect to thefirst cover14 in the ‘X’ direction that is orthogonal to both the axis of rotation ‘A’ and thesealing surface23 to achieve uniform compression of theseal24 along its circumference.
• According to yet another aspect of the invention, theenclosure10 includes a gap G1, having a pre-determined size, defined between ahinge component34 of thefirst cover14 and ahinge component32 of thesecond cover12, wherein, upon pivoting thesecond cover12 to the closed state, the gap G1 accommodates translation of thesecond cover12 with respect to thefirst cover14 in a direction ‘Y’ that is parallel to the axis of rotation ‘A’ to achieve uniform compression of theseal24 along its circumference.
• Referring now toFIGS. 1-6,enclosure10 is a waterproof, clam-shell style container that generally includes atop cover12 that is pivotably coupled to abottom cover14 along an axis of rotation ‘A’ by twohinges16 and18.Top cover12 pivots between an open position (seeFIG. 1) and a closed position (seeFIG. 3) with respect tobottom cover14, or vice versa. In a closed position, covers12 and14 define an interior region that is sized to contain an object. According to one aspect of the invention,enclosure10 is a battery pack that includes circuitry for establishing an electrical connection to terminals of abattery20 positioned within the interior region ofenclosure10. It should be understood thatenclosure10 is not limited to a battery pack, asenclosure10 is capable of storing any object.
• Covers12 and14 are injection-molded plastic components. Alternatively, covers12 and14 may be composed of aluminum and formed by a casting process, for example. It should be understood thatcovers12 and14 may be composed of any material and made by any forming process known to those skilled in the art without departing from the scope of the invention.
• Bottom cover14 includes an upwardly-extendingflange21. Agland22, in the form of a rectangular slot, is defined around the circumference of the outwardly-facingsealing surface23 offlange21. An elastomericradial seal24 is mounted ingland22 to bear on an interior surface oftop cover12. In use,seal24 is compressed in a downward direction (as shown) to prevent the introduction of water, air or other contaminants into the sealed interior ofenclosure10.
• Aflexible locking tab26 extends fromtop cover12.Locking tab26 is configured for releasably mating with arectangular slot28 that is defined on the outer surface ofbottom cover14. Positive engagement betweenlocking tab26 andslot28 locks covers12 and14 together such thatseal24 is compressed against the interior surface oftop cover12 and covers12 and14 are prevented from rotating with respect to each other to an open position.Locking tab26 is released from its complimentary recess by translating the free end oflocking tab26 inwardly and rotating one of thecovers12 and14 to an open position.
• Enclosure10 includes twohinges16 and18 that are each configured to accommodate translation oftop cover12 with respect to bottom cover14 (or vice versa) in the ‘X’ and ‘Y’ directions. In other words,hinges16 and18 each accommodate transverse shifting of an axis of rotation ‘A’ ofenclosure10 along the X-axis, as well as axial shifting oftop cover12 along the axis of rotation ‘A’, i.e., along the Y-axis, asseal24 is being compressed. The hinge design takes advantage of the forces applied byseal24, as it is compressed, to centertop cover12 ontobottom cover14. In other words,seal24 induces translation oftop cover12 in the ‘X’ and ‘Y’ directions (which are non-parallel and orthogonal axes) such that a substantially uniform compressive force is applied along the circumference ofseal24.
• Hinges16 and18 may be commonly referred to as floating, centering or self-centering hinges. Unlike many floating hinges which are only capable of floating along a single axis (typically the Z-axis), hinges16 and18 are configured to accommodate relative translation of one ofcovers12 and/or14 along an X-axis and a Y-axis of a Cartesian coordinate system. According to one aspect of the invention, hinges16 and18 are each configured to accommodate translation ofcover12 with respect to cover14 in two different, perpendicular directions ‘X’ and ‘Y’ upon pivotingcover12 to a closed state to achieve uniform compression ofseal24 along its circumference. It should be understood thatenclosure10 may include any number of hinges. Because hinges16 and18 are structurally and functionally equivalent, only the structure and function ofhinge18 will be described hereinafter for the purpose of simplifying the description of the invention.
• Hinge18 includes apin30 extending fromtop cover12 and aknuckle34 extending frombottom cover14.Pin30 andknuckle34 may also be referred to herein as hinge components.Pin30 is substantially cylindrical and defines an outer cylindrical surface. Each end ofpin30 is integrally connected totop cover12 by arib32 that extends from a hinge-side surface oftop cover12, as best shown inFIG. 3. Similarly,knuckle34 is integrally connected tobottom cover14 by tworibs33 that extend from a hinge-side surface ofbottom cover14.Knuckle34 defines an outer cylindrical surface and a substantially cylindricalinterior recess36.Recess36 is open-ended, i.e., contains an opening at its lower end, for receivingpin30. Adistended portion38 is defined on both free ends ofrecess36. As best shown inFIG. 9,distended portions38 extend along only a portion of width W2 ofknuckle34.
• As best shown inFIGS. 3 and 5,recess36 is sized to captively receivepin30. More particularly, a gap D2 separating opposingdistended portions38 ofknuckle34 is smaller than diameter D1 ofpin30. Accordingly, oncepin30 is positioned withinrecess36 it is captivated withinrecess36, thereby captivatingtop cover12 tobottom cover14. In assemblingpin30 intorecess36 ofknuckle34, thedistended portions38 ofknuckle34 deflect outwardly to accommodate the larger diameter D1 ofpin30 and snap back to return to their original positions oncepin30 is contained within recess36 (as shown inFIG. 5). Oncepin30 is captivated withinrecess36,pin30 can not be removed fromrecess36 unless a sufficient downward force is applied to deflectdistended portions38 ofknuckle34 outwardly enough to accommodate diameter D1 ofpin30. It should be understood that once pins30 ofhinges16 and18 are released from theirrecesses36,top cover12 is detached frombottom cover14, as shown inFIGS. 7-10.
• Eachhinge16 and18 accommodates translation oftop cover12 in the X and Y directions such that, immediately prior to locking enclosure10 (i.e., by engaginglocking tab26 in recess28),top cover12 is configured to center itself in or along the ‘X’ and ‘Y’ axes relative to bottom cover14 (or vice versa). Self-centering ofcovers12 and14 facilitates uniform compression ofseal24 against the interior surface oftop cover12 along the entire circumference ofseal24. In other words, the floating hinge design permits uniform compression of the entire circumference ofseal24 against the interior surface oftop cover12.
• As best illustrated inFIG. 4, immediately prior to lockingenclosure10, covers12 and14 are capable of self-centering in the Y-direction (i.e., along the Y-axis) such that compression ofseal24 on side S1 is substantially the same as the compression ofseal24 on side S2 ofenclosure10. To accomplish the self-centering action oftop cover12 along the Y-axis, a gap G1 is defined on both sides ofknuckle34. Gap G1 is the difference between a distance W1 separating the inwardly facing surfaces ofribs32 and a width W2 of the body ofknuckle34. According to one aspect of the invention gap G1 is about 0.013 inches and the total width ‘W’ ofenclosure10 is about 2.769 inches. According to one aspect of the invention, a ratio of the total width ‘W’ ofenclosure10 to the gap G1 is about 213:1.
• Top cover12 can translate relative tobottom cover14, or vice versa, along gap G1 in either direction along the Y-axis. In use, sincetop cover12 is relatively unconstrained in the Y-direction (by virtue of gap G1),seal24 will centertop cover12 along gap G1 untilseal24 applies substantially the same force againsttop cover12 along sides S1 and S2 ofenclosure10. According to an aspect of the invention, gap G1 accommodates translation ofcover12 with respect to cover14 in a direction ‘Y’ that is parallel to the axis of rotation ‘A’ to achieve uniform compression of theseal24 along its circumference.
• As best illustrated inFIG. 5, immediately prior to lockingenclosure10, covers12 and14 are also capable of centering themselves in the X-direction (i.e., along the X-axis) such that compression ofseal24 on side S3 is substantially the same as the compression ofseal24 on side S4 of enclosure10 (sides S3 and S4 are shown inFIG. 4). To accomplish the self-centering action oftop cover12 along the X-axis, a gap G2 is defined on both sides ofpin30. Gap G2 is the difference between the diameter D1 ofpin30 and a width D3 ofrecess36 ofknuckle34.
• The gap G2 is sufficiently large, and larger than gap G1, such thatcover12 can pivot overseal24 without interference toward the closed position ofenclosure10. According to one aspect of the invention gap G2 is about 0.045 inches and the total length ‘L’ of enclosure10 (seeFIG. 4) is about 2.482 inches. According to one aspect of the invention, a ratio of the total length ‘L’ ofenclosure10 to the gap G2 is about 55:1.
• Top cover12 can translate relative tobottom cover14, or vice versa, along gap G2 in either direction along the X-axis. In use, sincetop cover12 is relatively unconstrained in the X-direction (by virtue of gap G2),seal24 will center the top cover along gap G2 untilseal24 applies substantially the same force againsttop cover12 along sides S3 and S4 ofenclosure10. According to an aspect of the invention, gap G2 accommodates translation of thecover12 with respect to thecover14 in a direction ‘X’ that is orthogonal to both axis of rotation ‘A’ and sealingsurface23 to achieve uniform compression of theseal24 along its circumference.
• In designing a clam-shell enclosure having a fixed hinge, the following dimensional tolerances are accounted for to ensure sufficient compression of a radial seal: (1) the distance from a sealing surface of a first cover to the pin, (2) the size (e.g., diameter) of the pin, (3) the size (e.g., diameter) of the knuckle recess in the second cover, (4) the distance from the knuckle recess to the sealing surface of the second cover, (5) the distances between opposing sealing surfaces of the first cover, (6) the distances between opposing sealing surfaces of the second cover, and (7) the protruding height of the seal. Ordinarily, the protruding height of the seal is oversized to account for tolerances (1) through (5).
• Alternatively, by employing a floating hinge design, only the following dimensional tolerances are accounted for to ensure uniform compression of a radial seal: (a) the distances between opposing sealing surfaces of the first cover, (b) the distances between opposing sealing surfaces of the second cover, and (c) the protruding height of the seal. The floating hinge design compensates for tolerances (1) through (4) that were described above. Eliminating several of the accumulated tolerances provides for better control of the seal compression. In contrast, a large accumulation of tolerances makes it difficult to ensure appropriate compression of the seal. Additionally, eliminating several of the accumulated tolerances reduces the overall size ofseal24. A smaller seal is lighter, which reduces the entire weight ofenclosure10.
• By way of non-limiting example the enclosure described herein, or modified versions thereof, may be used in the following applications: a storage container, a battery pack, and a battery pack for a helmet-mounted night vision system.
• Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the invention. For example, according to the exemplary embodiment of the invention, pins30 are integral withtop cover12 andknuckle34 is integral withbottom cover14. According to another exemplary embodiment of the invention that is not shown herein, both covers12 and14 include knuckles and the pin is a separate component that engages the knuckles of bothcovers12 and14 (similar to a conventional door hinge). Additionally, it should be understood thatpin30 may be provided onbottom cover14 andknuckle34 may be provided ontop cover12 without departing from the scope or the spirit of the invention.

Claims (11)

What is claimed:

1. A waterproof, clam-shell style enclosure comprising:

a first cover;

a second cover that is hingedly coupled to the first cover to pivot about an axis of rotation between an open state and a closed state, wherein, in a closed state, the first cover and the second cover define an enclosed interior region of the enclosure for storing an object;

a seal positioned on a sealing surface of either the first cover or the second cover, wherein the seal is positioned to inhibit the passage of fluid or gas into or out of the enclosed interior region of the enclosure in the closed state of the enclosure; and

a hinge connecting the first cover to the second cover that is configured to accommodate translation of the second cover with respect to the first cover in two different, perpendicular directions ‘X’ and ‘Y’ upon pivoting the second cover to a closed state to achieve uniform compression of the seal along its circumference.

2. The enclosure ofclaim 1, wherein the hinge is configured to accommodate translation of the second cover with respect to the first cover along both an X-axis and a Y-axis of a Cartesian coordinate system.

3. The enclosure ofclaim 1, wherein the enclosure is a battery pack that includes circuitry for establishing an electrical connection to terminals of a battery.

4. The enclosure ofclaim 1, wherein the first cover is releasably captivated to the second cover.

5. The enclosure ofclaim 1, wherein the seal is formed from an elastomeric material.

6. The enclosure ofclaim 1 further comprising a flexible tab extending from one of the covers, wherein the flexible tab is configured to releasably engage the other cover to retain the enclosure in a closed state.

7. The enclosure ofclaim 6 further comprising a recess formed in said other cover, wherein the flexible tab is configured to releasably engage the recess of said other cover to retain the enclosure in a closed state.

8. A waterproof, clam-shell style enclosure comprising:

a first cover;

a second cover that is hingedly coupled to the first cover to pivot about an axis of rotation between an open state and a closed state, wherein, in a closed state, the first cover and the second cover define an enclosed interior region of the enclosure;

a seal positioned on a sealing surface of either the first cover or the second cover, wherein the seal is positioned to inhibit the passage of fluid into the enclosed interior region of the enclosure in the closed state of the enclosure;

a hinge connecting the first cover to the second cover that includes a knuckle extending from either the first cover or the second cover and a pin positioned within a recess formed in the knuckle, wherein the knuckle is configured to rotate about the pin; and

a gap, having a pre-determined size, defined between an exterior surface of the pin and the recess of the knuckle, wherein, upon pivoting the second cover to the closed state, the gap accommodates translation of the second cover with respect to the first cover in a direction that is orthogonal to both the axis of rotation and the sealing surface to achieve uniform compression of the seal along its circumference.

9. The enclosure ofclaim 8, wherein the recess of the knuckle and the outer surface of the pin are both substantially cylindrical, and a diameter of the recess is greater than a diameter of the pin such that a difference between the diameters establishes the gap.

10. A waterproof, clam-shell style enclosure comprising:

a first cover;

a second cover that is hingedly coupled to the first cover to pivot about an axis of rotation between an open state and a closed state, wherein, in a closed state, the first cover and the second cover define an enclosed interior region of the enclosure;

a seal positioned on a surface of either the first cover or the second cover, wherein the seal is positioned to inhibit the passage of fluid into the enclosed interior region of the enclosure in the closed state; and

a gap, having a pre-determined size, defined between a hinge component of the first cover and a hinge component of the second cover, wherein, upon pivoting the second cover to the closed state, the gap accommodates translation of the second cover with respect to the first cover in a direction that is parallel to the axis of rotation to achieve uniform compression of the seal along its circumference.

11. The enclosure ofclaim 10, wherein the hinge component of the first cover is a hinge knuckle and the hinge component of the second cover is two opposing ribs, wherein the hinge knuckle is positioned between the two opposing ribs, and the gap is formed between the hinge knuckle and at least one of the opposing ribs.

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