Patent Description:
In applications utilizing sensitive electrical components, it is sometimes required that these components are protected from damaging exposure to environmental contaminants such as dust, dirt, and water. Optimally, this is accomplished with a water-tight enclosure. In consumer products, this enclosure should be as low cost as possible and easily assembled. Additionally, it is common that there is a need for electrical conductors to pass through this enclosure to connect with the electronic components. These entry points must not provide a means for contaminants to enter the enclosure, and shall also be easily assembled in a manner suitable for mass production.

For consumer products, the optimum choice of material for electronics enclosures is thermoform and/or thermoset plastics due to their versatility and low cost. Conventionally, an effective method for sealing these plastic enclosures utilizes a silicone rubber seal captured in the overlap of two halves of the enclosure. These seals generally work well with plastic enclosures because they do not require the precision and high clamp forces of more common compression seals. Because there currently does not exist a practical means for providing for entry of cables at the enclosure separation area, through-wall entries are typically used. There are some cost effective means for sealing this type of cable entry, however, these sealing means are not always particularly reliable, and can present a restriction on the size of connectors that may be pre-installed on the ends of the cables, since the connectors generally must pass through an opening in the wall of the enclosure.

<CIT> discloses a waterproof structure of an electric junction box, in which a grommet can securely prevent water from entering into a case even when the water has high energy. <CIT> discloses a junction box assembly configured to enclose an electrical assembly, and including a junction box cover and a base member configured to enable sealing.

The invention provides a cable entry sealing mechanism as defined in claim <NUM>. Preferred embodiments of the invention are defined in claims <NUM>-<NUM>.

The features of the disclosed technology, and the advantages, are illustrated specifically in embodiments now to be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:.

It should be noted that all the drawings are diagrammatic and not drawn to scale. Relative dimensions and proportions of parts of these figures have been shown exaggerated or reduced in size for the sake of clarity and convenience in the drawings. The same reference numbers are generally used to refer to corresponding or similar features in the different embodiments. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.

The following terms are used throughout the description, the definitions of which are provided herein to assist in understanding various aspects of the subject disclosure.

As used herein, the term "electronics", refers to any of a printed circuit board assembly, power supply, battery, and most any electronic or electrical component or assembly.

As used herein, the terms "enclosure", "electronics enclosure", and "housing" are used interchangeably, and refer to any electronics enclosure in which electronic or electrical components are to be contained.

As used herein, the terms "aperture" and "cut-out" are used interchangeably, and refer to an opening or cut-out portion of the enclosure.

The disclosed technology generally described hereinafter provides for cable entry sealing system. With reference to <FIG>, a cable entry sealing system <NUM> is provided. The cable entry sealing system <NUM> provides for an electronics enclosure <NUM>, comprising a first enclosure half <NUM> and a second enclosure half <NUM>. The first enclosure half <NUM> is generally box-shaped and can be formed of any material sufficient to be rigid enough to adequately enclose the electronics housed therein. However, it should be understood that the first enclosure half <NUM> can be of any shape required to contain the desired electrical components within the enclosure <NUM>.

The second enclosure half <NUM> is generally planar, e.g. a cover or lid. However, the second enclosure half <NUM> can be most any shape capable of effectively mating or combining with the first enclosure half <NUM> to form a complete enclosure <NUM>. The second enclosure half <NUM> can be formed of material that is the same or different than that of the first enclosure half <NUM>.

The first enclosure half <NUM> comprises at least one sidewall <NUM> having an aperture <NUM> located therein (shown in <FIG>). The aperture <NUM> is formed from a cut-out portion of the sidewall <NUM>. The aperture <NUM> allows for electrical conductors confined within a cable to pass through the wall of the enclosure <NUM>.

As shown in <FIG>, the enclosure <NUM> further comprises a sealing member <NUM> positioned between the first enclosure half <NUM> and the second enclosure half <NUM> to provide a seal. The sealing member <NUM> operates in a radial manner so as to seal along the perimeter of the enclosure <NUM>. In some embodiments, the sealing member <NUM> can be formed of a single sealing material encompassing the perimeter of the enclosure <NUM>. In some embodiments, the sealing member <NUM> is a multi-lip radial seal. In other embodiments, the sealing member <NUM> can be an o-ring, quad-ring, or other sealing means of similar elastomeric form.

The cable entry sealing system <NUM> further comprises a cable entry <NUM>. The cable entry <NUM> is positioned within the aperture <NUM> located in the sidewall <NUM>. As shown in <FIG>, the cable entry <NUM> comprises a cable <NUM>, a cable grommet <NUM>, and a cable grommet support groove <NUM>. In some embodiments, the cable <NUM> is further encompassed by a cable jacket <NUM>. The cable <NUM> and the cable jacket <NUM> extend from the exterior of the enclosure <NUM>, passing through the cable grommet <NUM> to access the interior of the enclosure <NUM>. The cable <NUM> includes a distal end 22a which terminates within the enclosure <NUM>, and can include connectors or terminals (not shown) for electrically and physically connecting to, for example, a printed circuit board or terminal block within the enclosure <NUM>.

In some embodiments, the cable jacket <NUM> is fused to the cable grommet <NUM>, where sealing between the cable grommet <NUM> and the cable <NUM> is accomplished by fusing the cable grommet <NUM> with the cable jacket <NUM> utilizing, for example, a plastic over-mold process. A plastic injection molding process can be utilized in which the cable grommet <NUM> is molded over the cable jacket <NUM> to provide a seal between the cable grommet <NUM> and the cable jacket <NUM>. In an embodiment, the cable grommet <NUM> is molded over the cable <NUM> to provide a seal between the cable grommet <NUM> and the cable <NUM>. The seal between the cable grommet <NUM> and the cable <NUM> and/or the cable jacket <NUM> can be impermeable, water-tight, air-tight, and/or water-resistant.

In some embodiments, the cable entry <NUM> can anchor the cable <NUM> to the enclosure <NUM>, and provides an integrated strain relief feature which prevents mechanical forces applied at the exterior of the cable from being transferred to electrical terminations at the distal end 22a of the cable <NUM> within the enclosure <NUM>, and helps to preserve the electrical and mechanical integrity of the cable <NUM>.

With reference to <FIG>, in some embodiments, the sealing member <NUM> is a multi-lip radial seal. In some embodiments, the multi-lip radial seal is provided in a singular, continuous loop (as shown in <FIG>). The sealing member <NUM> provides sealing or other lip elements <NUM>, wherein such sealing or other lip elements <NUM> can be in direct contact with the first enclosure half <NUM>, (as best shown in <FIG>). The sealing member <NUM> or multi-lip radial seal allows for multiple contact points along the perimeter of the enclosure <NUM> thus providing a seal. It should be understood by one skilled in the art that the sealing member <NUM> can be comprised of any elastic or other compliant material that allows for the transitions included along the perimeter of the enclosure <NUM> and/or the cable grommet <NUM>, yet still providing compression.

With reference to <FIG>, the cable grommet <NUM> is shown. The cable grommet has a first portion <NUM> and a second portion <NUM>. In some embodiments, the first portion <NUM> and second portion <NUM> are generally U-shaped, where a recess <NUM> is formed therebetween. The cable grommet <NUM> can be formed by the molding of a soft or compliant material. In some embodiments, the cable grommet <NUM> is formed of thermoplastic elastomer or flexible material. It should be understood by one skilled in the art that the cable grommet <NUM> can be made of any material sufficiently compliant to adequately form a water-tight seal.

The cable grommet <NUM> is generally shaped to fit tightly within the aperture <NUM>. In some embodiments, the cable grommet <NUM> is molded as a single piece. In other embodiments, the cable grommet <NUM> can be formed of two molded pieces mated together to form a single piece.

As shown in <FIG>, the cable grommet <NUM> includes a first portion <NUM> having a first lip <NUM>, where the first lip <NUM> includes an outer edge <NUM> and a first lip face <NUM>. The cable grommet second portion <NUM> includes a second lip <NUM>, where the second lip <NUM> includes an outer edge <NUM>, a second lip face <NUM>, and a projection <NUM> extending beyond the first lip face <NUM>. The projection <NUM> includes an interior surface <NUM> and an opposing exterior surface <NUM>. The first lip face <NUM> and the interior surface <NUM> of the projection <NUM> converge to form a right angle. As shown in <FIG>, the cable jacket <NUM> extends from the second portion <NUM> through the first portion <NUM>, where the distal end 22a of the cable <NUM> terminates within the interior of the housing.

With reference to <FIG>, the cable grommet support groove <NUM> is shown. The cable grommet support groove <NUM> is located within the sidewall <NUM> of the first enclosure half <NUM>, and essentially frames the aperture <NUM>. By framing or contouring the aperture <NUM>, the cable grommet support groove <NUM> positions the flexible cable grommet <NUM> in the correct and proper location to ensure reliable assembly of the first enclosure half <NUM> and the second enclosure half <NUM>. In some embodiments, the cable grommet support groove <NUM> comprises an optional cutout <NUM> (as shown in <FIG>), which allows for water drainage on the outside of the cable grommet <NUM>. This optional cutout <NUM> prevents water from becoming trapped against or within the cable grommet support groove <NUM>, and thus reduces the likelihood of penetration of water into the enclosure <NUM>.

As shown in <FIG>, the cable grommet support groove <NUM> can be generally U-shaped, and shaped to receive and communicate with the cable grommet <NUM> to complete the sidewall <NUM>. The sidewall <NUM> further includes an offset face <NUM> having a ledge <NUM>. The offset face <NUM> correlates with the projection <NUM> of the cable grommet second portion <NUM> when the cable grommet <NUM> is installed. More specifically, and as shown in <FIG>, the offset face <NUM> engages with the interior surface <NUM> of the projection <NUM>, such that when the cable grommet <NUM> is installed within the cable grommet support groove <NUM>, the interior surface <NUM> and the offset face <NUM> form a contiguous portion of the sidewall <NUM>.

In some embodiments, the offset face <NUM> is offset inwardly toward the interior of the enclosure so to create the ledge <NUM> which works to prevent the sealing member <NUM> from sliding down and falling out of the gland. The first lip face <NUM> of the first portion <NUM> abuttingly engages with the ledge <NUM>, such that when the cable grommet <NUM> is installed, the first lip face <NUM> and the ledge <NUM> form a contiguous portion.

Referring to <FIG> and <FIG>, the cable entry <NUM> further comprises a sealing face <NUM>. The sealing face <NUM> is located on the interior side of the enclosure <NUM>. It should be understood that the width of the sealing face <NUM> can be widened in order to improve sealing capability. The aperture <NUM> is sized so that a compressive force is maintained with the recess <NUM> (as shown best in <FIG>), which increases the dimensional interference as the cable grommet <NUM> is pressed within the grommet support groove <NUM>. It should be understood that the aperture <NUM> can be of any size that complements the size and shape of the cable grommet <NUM>.

As shown in <FIG>, in some embodiments, the sealing face <NUM> further comprises a triangular cross-section or raised knife edge <NUM>. The raised knife edge <NUM> extends over the length of or the perimeter of the sealing face <NUM>. When the cable grommet <NUM> is installed, this triangular cross-section or knife edge <NUM> pushes against the cable grommet <NUM> to provide an increase in localized pressure (or increased compression), which improves sealing.

With reference to <FIG>, when the cable grommet <NUM> is properly installed, the recess <NUM> and the sealing face <NUM> are abuttingly engaged to form a seal between the grommet and the enclosure housing. The cable grommet support groove <NUM> cooperates with the cable grommet <NUM> to receive and engage with the outer edge <NUM> of the second portion <NUM>, which ensures that the recess <NUM> and the sealing face <NUM> remain abuttingly engaged. Once the cable grommet <NUM> has been properly installed, the sealing member <NUM> can be provided (as shown in <FIG>). The sealing member <NUM> abuttingly engages the offset face <NUM> and the interior surface <NUM> of the projection, and is adjacent to the ledge <NUM> (not shown in <FIG>) and the first lip face <NUM>. When installed, the sealing member <NUM> remains flush against the housing, sealing itself against the offset face <NUM> and the interior surface <NUM> of the projection.

In the presently disclosed cable entry sealing system <NUM>, the connection between the recess <NUM> of the cable grommet <NUM> and the sealing face <NUM> (not shown in <FIG>) provides for a water-tight seal and/or a seal that can prevent environmental contaminants from entering the enclosure <NUM>. The sealing member <NUM> utilizes a plurality of flexible ribs (or sealing elements <NUM> as shown in <FIG>), which create a high compliant interface that can conform to surface variances that may be present in the offset face <NUM> and the interior surface <NUM>. The unique shape of the cable grommet <NUM> allows for the gland profile to be completed, and the sealing member <NUM> can perform as though there was no aperture <NUM> or cutout within the sidewall <NUM> of the first enclosure half <NUM>.

With reference to <FIG>, the fully assembled cable entry <NUM> is shown. In some embodiments, the first enclosure half <NUM> comprises at least one fastener receptacle <NUM>. As shown in <FIG>, two fastener receptacles <NUM> are shown. Each fastener receptacle <NUM> receives a fastener <NUM> to engage the first enclosure half <NUM> with the second enclosure half <NUM> to essentially form the complete electronics enclosure <NUM>. In some embodiments, the fastener can be selected from a screw, bolt, or the like. The fasteners <NUM> allow for compression against the second lip face <NUM> to press the cable grommet <NUM> tightly in the aperture <NUM>, thus ensuring a seal between the recess <NUM> and the sealing face <NUM>.

In an embodiment, the cable grommet <NUM> is formed of a compliant material, which is ideal for sealing the enclosure <NUM>. However, the relatively soft material can present challenges when it comes to maintaining the location and flatness of interior surface <NUM>. To overcome this issue, a grommet support <NUM> is provided to reinforce and maintain the geometry of the grommet <NUM>, and to ensure reliable engagement between the sealing member <NUM> or multi-lip seal and interior surface <NUM>.

Claim 1:
A cable entry sealing mechanism, comprising:
an enclosure (<NUM>) having a first enclosure half (<NUM>) and a second enclosure half (<NUM>), the first enclosure half comprising at least one sidewall (<NUM>) having an aperture (<NUM>) therein, wherein the enclosure defines an interior;
a cable entry (<NUM>) positioned within the aperture (<NUM>), wherein said cable entry comprises a cable grommet support groove (<NUM>) formed within the sidewall of the first enclosure half and framing the aperture; and
a cable grommet (<NUM>), wherein the cable grommet is generally U-shaped, comprising a first portion (<NUM>) and a second portion (<NUM>); the first portion comprising a first lip (<NUM>), the first lip having a first outer edge (<NUM>) and a first lip face (<NUM>), and the second portion comprising a second lip (<NUM>), the second lip having a second outer edge (<NUM>), a second lip face (<NUM>), and a projection (<NUM>) extending beyond the first lip face, wherein a recess (<NUM>) is formed between the first portion and the second portion;
wherein the cable grommet support groove (<NUM>) is shaped to receive and communicate with the cable grommet (<NUM>);
wherein the sidewall (<NUM>) further comprises an offset face (<NUM>) having a ledge (<NUM>);
wherein the offset face (<NUM>) is configured to engage with the projection (<NUM>), such that when the cable grommet (<NUM>) is installed within the cable grommet support groove (<NUM>), the projection and the offset face form a first contiguous portion of the sidewall; and
the cable entry sealing mechanism further comprising a radial seal (<NUM>) configured to abuttingly engage the first contiguous portion of the sidewall to provide a seal at the perimeter of the enclosure.