Patent Grant
7708593
The subject matter herein relates generally to electrical connectors and, more particularly, for electrical connectors that are coupled with one or more cables.
Some known electrical connectors are joined with cables to electrically couple the connectors with the cables. For example, the connectors may include contacts that engage a mating device. The contacts electrically join the connector with the mating device. The cable typically includes one or more conductors enclosed by an insulative jacket extending along the interior of the cable throughout the length of the cable. The cable is connected with the connector with the conductors electrically terminated with the contacts to electrically couple the cable with the contacts. Thus, the connector electrically connects the mating device with the cable. Electrical power and/or signals may then be communicated between the mating device and the cable. In applications where the mating device is a solar module or panel, the connector may communicate electric potential or current from the solar module or panel to another mating device via the cable.
In some applications, the cables joined with the connectors may experience significant forces that pull the cable away from the housing of the connector. For example, environmental factors such as ice and snow may add weight to the cables joined to connectors on solar panels. This additional weight may pull the cables away from the connectors. If the cables are not affixed to the connectors in a sufficiently strong manner, the cables may become detached from the housings of the connectors.
Some known connectors include retention mechanisms that assist in preventing the cable from being separated from the connector housing. But, these retention mechanisms may be relatively large. For example, some known solar module connectors include pinch ring and nut combinations to secure cables to the connector housings. The pinch ring is a ring that is placed around the cable. The pinch ring includes several slots that permit the ring to be compressed down onto the cable. The nut is placed into the connector. The pinch ring is screwed into the nut to compress the pinch ring onto the cable and to couple the cable with the connector. The pinch ring is compressed around the cable when the nut is screwed down or tightened onto the connector. But, the size of the nut limits the size of the connector. That is, the size of the connector typically must be at least as large as the nut. As a result, the profile height of the connector is limited by the size of the nut. In certain applications, the size of the nut may require the connector to have a profile height that is too large. For example, the location in which some solar module connectors are required may be too small to fit a connector having a nut and pinch ring combination.
The interface between the cable and the housing at the opening provides a location where moisture can enter into the housing. In connectors that have too small of a profile to permit use of the pinch ring and nut combination, the cable/housing interface may be exposed to the atmosphere surrounding the connector. In conditions where the cable and housing experience changes in temperature, differences between coefficients of thermal expansion between the cable and the housing may result in a gap forming at the cable/housing interface. For example, the housing may be formed of a material that expands and contracts a greater distance than the material of the outer jacket of the cable over a common change in temperature. When the connector is used in environments experiencing relatively large temperature changes, the differences in coefficients of thermal expansion may cause a relatively large gap to be formed. The gap permits moisture to seep into the interior of the housing, where the moisture can electrically short the contacts or other electrical components of the housing.
Thus, a need exists for a connector assembly that affixes cables to connectors in such a manner to maintain a relatively small profile height of the connector while preventing moisture from entering into the housing.
In one embodiment, an electrical connector includes a housing, a cable, a contact and an encapsulant. The housing extends from a cable exit end to an opposite end along a longitudinal axis and from a mounting face to a top face along a vertical axis. The housing includes a cable opening that extends into the cable exit in a direction parallel to the longitudinal axis and a window extending from the housing from the top face toward the mounting face in a direction parallel to the vertical axis. The cable extends through the window and into the housing through the cable opening. The contact is held by the housing and is configured to electrically couple the cable with a mating device when the mounting face of the housing is mounted to the mating device. The encapsulant is disposed within the window to seal an interface between the cable and the housing. The encapsulant prevents ingress of moisture into the housing through the interface.
In another embodiment, another electrical connector is provided. The connector includes a housing, a cable, a contact and an encapsulant. The housing extends from a cable exit to an opposite end along a longitudinal axis and from a mounting face to a top face along a vertical axis. The housing frames a window extending through the housing from the top face to the mounting face. The cable is received into the housing through the cable exit. At least a portion of the cable is disposed within the window. The contact is held by the housing and is configured to electrically couple the cable with a mating device when the mounting face of the housing is mounted to the mating device. The encapsulant is disposed within the window to seal an interface between the cable and the housing. A web portion of the housing is disposed between the cable exit and the window to reduce a force that is imparted on the encapsulant to prevent separation between the encapsulant and at least one of the housing and the cable.
The connector 100 includes a housing 104 that extends between a cable exit 108 and an opposite end 106 along a longitudinal axis 110 and between opposite sides 112, 114 along a lateral axis 116. The housing 104 also extends from a mounting face 118 to an opposite top face 120 along a vertical axis 122. In the illustrated embodiment, the longitudinal axis 110, lateral axis 116 and vertical axis 122 are perpendicular to each another. The mounting face 118 engages the solar module (not shown) when the connector 100 is mounted to the solar module.
In one embodiment, the housing 104104 includes or is formed from a dielectric material. The housing 104 may be a rigid, unitary body that is molded from a dielectric material. By way of example only, the housing 104 may be molded from a polyester, such as polybutylene terephthalate (PBT). In one embodiment, the housing 104 is formed of 30% glass fiber filled PBT. However, other materials and composites may be used to form the housing 104. The housing 104 may be formed by overmolding the housing 104 over portions of the cables 102. Alternatively, the housing 104 may be molded with the cables 102 later loaded into the housing 104 through the cable exit 108.
The cables 102 include one or more conductors (not shown) that are electrically coupled with contacts 224 (shown in
The connector 100 includes a front end cover 126 and a rear end cover 128 in the illustrated embodiment. As described below, the front end cover 126 encloses a contact window 222 (shown in
The cable windows 206 define openings into the housing 104 that extend from the top face 120 toward the mounting face 118 in directions parallel to the vertical axis 122. While two cable windows 206 are shown in
The housing 104 includes inner walls 208, 210 that oppose one another across each of the cable windows 206. A portion 216 of each of the cables 102 is disposed in the cable windows 206 between the inner walls 208, 210 of each cable window 206. In the illustrated embodiment, each inner wall 208 includes a cable opening 212 through which the cables 102 extend. The cable openings 212 may be formed by the overmolding of the housing 104 onto the cables 102. The cable openings 212 are aligned with the longitudinal axis 110 of the housing 104. For example, the cables 102 may extend into the housing 104 through the cable openings 212 in a direction that is oriented approximately parallel to the longitudinal axis 110. The cable openings 212 may have a size that is approximately the same as the cables 102. For example, the cables 102 may have circular cross-sections and the cable openings 212 may be circular in shape. The diameters of the cable openings 212 may be approximately the same size as, or slightly smaller than, the diameters of the cables 102.
The housing 104 includes additional cable openings 214 disposed in the cable exit 108 of the housing 104 through which the cables 102 extend. Similar to the cable openings 212, the cable openings 214 may be formed when the housing 104 is overmolded onto the cables 102. As shown in
The housing 104 includes the contact window 222 in the illustrated embodiment. The contact window 222 defines an opening into the housing 104 that extends from the top face 120 toward the mounting face 118 in a direction that is parallel to the vertical axis 122. In one embodiment, the contact window 222 extends completely through the housing 104 from the top face 120 to the mounting face 118. The housing 104 frames the contact window 222 such that the housing 104 surrounds the contact window 222 from the top face 120 to the mounting face 118. One or more of the contacts 224 are held by the housing 104 and extend into the contact window 222. The contact window 222 may provide visual access to the contacts 224 to ensure that the contacts 224 engage mating contacts (not shown) of a mating device (not shown) when the connector 100 is mounted to the mating device. For example, the contacts 224 may be soldered or welded to the mating contacts.
The encapsulant 400 may be fluidly dispensed into the cable windows 206 and the contact window 222 after mounting the connector 100 to a mating device (not shown), such as a solar module. For example, the encapsulant 400 may be loaded into the cable windows 206 and/or the contact window 222 when the encapsulant 400 is in a state that allows the encapsulant 400 to flow like a liquid. The back end cover 128 and the front end cover 126 (shown in
The encapsulant 400 in the cable windows 206 seals the interface between the cables 102 and the housing 104. For example, the encapsulant 400 may seal the interface between the cables 102 and each of the inner walls 208, 210 (shown in
The encapsulant 400 seals the interface between the cables 102 and the housing 104 during changes in temperature of the connector 100. For example, the outer jackets 124 of the cables 102 may have a coefficient of thermal expansion (CTE) that differs from the CTE of the housing 104. In one embodiment, the cables 102 have a CTE that is less than a CTE of the housing 104. The lower CTE of the cables 102 causes the cables 102 to expand or contact a smaller distance than the housing 104 in one or more directions for a common change in temperature. The different amounts of expansion and contraction between the cables 102 and the housing 104 for a common temperature change may result in a gap being formed between the cables 102 and the housing 104 at the interfaces between the cables 102 and the housing 104. For example, a gap may form at the interface between the cables 102 and the housing 104 at the cable openings 212. The encapsulant 400 seals this interface and any gap that forms at the interface to prevent ingress of moisture into the housing 104 through this interface.
In one embodiment, the encapsulant 400 has a CTE that is less than a CTE of the housing 104 and is greater than a CTE of the outer jackets 124 of the cables 102. For example, for a common change in temperature, the CTE of the encapsulant 400 may cause the encapsulant 400 to expand and contract a greater distance than the outer jackets 124 of the cables 102 but a lesser distance than the housing 104 in one or more directions. The CTE of the encapsulant 400 may be closer in value to a CTE of the housing 104 than to a CTE of the outer jackets 124. For example, the CTE of the encapsulant 400 may more closely match a CTE of the housing 104 than a CTE of the outer jackets 124. As described above, the encapsulant 400 may be a flexible material relative to the housing 104. The flexible characteristic of the encapsulant 400 and the CTE of the encapsulant 400 may enable the encapsulant 400 to maintain the seal at the interface between the cables 102 and the housing 104 to prevent a gap from forming over a change in temperature that would otherwise form a gap at the interface. For example, over a common temperature change, a gap would form at the cable/housing interface at the cable openings 212 if the encapsulant 400 was not disposed in the cable windows 206, while no gap would form at the interface if the encapsulant 400 is disposed in the cable windows 206.
In one embodiment, the encapsulant 400 may have an insufficiently low UV rating to withstand being exposed to sunlight. For example, the encapsulant 400 may break down and fail to seal the interfaces between the cables 102 and the housing 104 after being exposed to UV light for a sufficiently long time. In order to protect the encapsulant 400 from exposure to UV light, the rear end cover 128 and front end cover 126 may be placed over the cable windows 206 and the contact window 222, respectively. The front end cover 126 and rear end cover 128 may be formed of UV-rated materials that block all or substantially all of the UV light that is incident upon the connector 100. In one or more embodiments where the connector 100 is used with a solar module in an outside environment, the UV-rated front and rear end covers 126, 128 can protect the encapsulant 400 from UV light.
The web portion 218 of the housing 104 prevents the encapsulant 400 from being separated from the housing 104 at the interfaces between the encapsulant 400 and each of the inner walls 208, 210 (shown in
The web portion 218 may isolate the encapsulant 400 from the forces that could separate the encapsulant 400 from the interfaces between the encapsulant 400 and the housing 104 and between the encapsulant 400 and the cables 102. For example, the web portion 218 can prevent or reduce movement of the cables 102 from imparting forces on the encapsulant 400 by isolating the portions 216 (shown in
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. § 112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
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