Patent Grant
8753133
The present invention relates generally to an electrical power connector and more particularly to a heavy duty power connector having a higher reliability ground and that is more ergonomic and user friendly than traditional heavy duty power connectors.
Class L electrical power connectors are well known in the art and are standard power connectors that have been in use for at least 50 years. These types of connectors are designed to Military Specification MIL-DTL-22992 to be suitable for heavy duty use in industrial and military applications. Typically, Class L connectors are configured with different shell sizes ranging from 28 to 52 and they are configured to operate with conductor sizes that range from size 6 to 4/0 AWG and are used to operate with electrical currents ranging from 40 to 200 amperes. Because these connectors are for heavy duty uses and large power applications, it is important, from a safety and operational perspective, that the connector has a suitable strain relief and that the shell maintains continuity to the ground pin(s) (this is also a requirement of the MIL-SPEC). In current Class L connectors this is accomplished by using an aluminum back shell and a wire mesh Kellems grip. The continuity is achieved by bonding the ground pin(s) together in the front shell of the connector via a metal ring. The back shell is screwed and tightened to the front shell and the metal of the back shell bonds to a metal ground ring. This creates continuity between the entire connector body and the ground pin(s). One view of a prior art Class L connector is shown in
Unfortunately, the aluminum back shell and Kellems grip used with current Class L connectors have several undesirable characteristics. First, because the metal body of the connector is exposed to the environment, these connectors can freeze making handling difficult. Second, because the aluminum back shell used to create ground continuity is large, the connectors are large, bulky and non-ergonomic. Third, because these connectors are used in heavy duty applications and the Kellems grip is exposed to the environment, the Kellems grip tends to fray overtime causing individual wires of the wire mesh to stick out of the grip. Thus, when a user grabs the grip, the frayed wires tend to cut the hand of the user.
An electrical connector is provided and includes a connector shell defining a connector shell cavity and having a connector nose end and a connector base end, wherein the connector shell includes a connector shell internal threaded portion proximate the connector base end. The electrical connector further includes a contact insert having a power contact carrier, a ground contact carrier and a ground plane, wherein the ground contact carrier is conductively connected to the ground plane. Additionally, a bonding nut is included and has a bonding nut threaded portion, wherein the contact insert and bonding nut is contained within the connector shell cavity to be proximate the connector base end, such that the bonding nut threaded portion engages the connector shell internal threaded portion to contact the ground plane.
An electrical connector assembly is provided and includes a contact insert, a connector shell and a bonding nut. The contact insert includes an insert front, an insert rear, a ground contact carrier, a power contact carrier and a ground plane, wherein the power contact carrier and ground contact carrier are conductively communicated with the insert front and the insert rear, and where the ground contact carrier is conductively connected to the ground plane. The insert front is configured to associate with a compatible electrical interface and the insert rear is configured to associate with a conductor of a cable. Additionally, the connector shell is configured to contain at least a portion of the contact insert and includes a connector nose end and a connector base end, and wherein when the contact insert is contained within the connector shell, the insert rear is located relative to the connector base end such that when the conductor of the cable is associated with the insert rear, the conductor is at least partially located within the connector shell. When the contact insert is contained within the connector shell, the bonding nut is securely associated with the connector shell such that the connector shell, the ground plane, the ground contact carrier and the bonding nut are electrically and conductively connected.
A method for assembling an electrical connector is provided, wherein the electrical connector includes a connector shell defining a connector shell cavity and having a connector nose end, a connector base end and a connector shell internal threaded portion proximate the connector base end. The electrical connector includes a contact insert having a contact rear, a power contact carrier, a ground contact carrier and a ground plane, and a bonding nut having a bonding nut threaded portion. The method includes inserting the contact connector into the connector shell cavity such that the contact rear is proximate the connector base end, associating the bonding nut with the connector shell cavity such that the connector shell internal threaded portion and the bonding nut threaded portion engage each other whereby the bonding nut compresses the ground plane, connecting a power conductor of a cable with the power contact carrier and a ground conductor of the cable with the ground contact carrier and associating a pre-mold material with the connector base end of the electrical connector to cover a portion of the contact insert, a portion of the connector base end and a portion of the cable.
The foregoing and other features and advantages of the present invention will be more fully understood from the following detailed description of illustrative embodiments, taken in conjunction with the accompanying drawings in which like elements are numbered alike in the several Figures:
Referring to
In accordance with the present invention, referring to
Referring again to
It should be appreciated that the at least one adjustment notch 134 allows a tool to be used to install and remove the bonding nut 130 from the shell cavity 104. When being installed, a portion of the adjustment tool fits into the at least one adjustment notch 134 to engage the bonding nut 130 and to rotate the bonding nut 130 in a first direction to be threadingly and tightly screwed into the shell cavity 104 such that the bonding nut 130 compresses the ground plane 118. When being removed, the tool is used to rotate the bonding nut 130 in a second direction. It should be appreciated that the connector shell 102, the ground plane 118 and the bonding nut 130 are preferably constructed from a conductive material, such as a conductive metallic material. Accordingly, when the bonding nut 130 is tightly associated with the connector shell 102 such that the bonding nut 130 compresses the ground plane 118, the above arrangement advantageously provides ground continuity between the connector shell 102, the ground plane 118, the bonding nut 130 and the at least one ground contact carrier 116. It should be appreciated that the bonding nut 130 may also be installed without a tool.
Referring to
It should be appreciated that in one embodiment, the insert rear 152, 352 has a greater diameter than the insert front 154, 354 such that a lip 158, 358 is formed. The contact insert 106, 306 is placed into the connector shell cavity 104 of connector shell 102 by inserting the contact insert 106, 306 into the opening of the connector shell 102 proximate the base end 110 to be located within the connector shell cavity 104 such that the insert front 154, 354 is proximate the nose end 108 and the insert rear 152, 352 is proximate the base end 110. The internal surface of the connector shell 102 has a rim (or protruding surface) and is configured such that when the contact insert 106, 306 is located within the connector shell 102, the lip 158, 358 of the insert body 150, 351 contacts the rim and is prevented from passing through the connector shell 102 and exiting out of the opening of the connector shell 102 proximate the nose end 108.
The insert rear 152, 352 includes a conductive ground plane 118 located on the surface of the insert rear 152, 352 where the ground plane 118 is conductively attached to the ground contact carriers 116. In accordance with the invention, the ground plane 118 may be conductively attached to the ground contact carriers 116 via any method suitable to the desired end purpose, such as soldering the ground plane 118 to the ground contact carriers 116. In still yet other embodiments, the ground plane 118 may be conductively attached to the ground contact carriers 116 via a mechanical connection (such as a clip or mounting screw) or the ground contact carriers 116 may be integrated with the ground plane 118 as one piece of conductive material.
It should be appreciated that the ground plane 118, ground contact carriers 116, bonding nut 130 and connector shell 102 are constructed from an electrically conductive material, such as a metallic material. This configuration advantageously allows for ground continuity when the electrical connector is assembled.
Referring to
Referring to
It should be appreciated that the present invention can be used with other types of cabling and is not limited to Class L connectors. Additionally, it should be further appreciated that the present invention may be accomplished using any method or device suitable to the desired end purpose. For example, the invention may use some or all of the characteristics and/or techniques as disclosed in U.S. patent application Ser. No. 12/856,220, filed on Aug. 13, 2010 and entitled “An Electrical Connector and A Method for Manufacturing Same,” the contents of which are incorporated herein by reference in its entirety.
Accordingly, the electrical connector 100 of the present invention may be configured with any size shell (for example, may be configured with different shell sizes ranging from 28 to 52) and may be configured to operate with conductor sizes that range from size 6 AWG to 4/0 AWG (greater or smaller) and may be used to operate with electrical currents ranging from 40 to 200 amperes (greater or smaller). Additionally, the method of the invention as disclosed herein may be used with other embodiments and thus may be used with any size or type of connector and is thus, not limited to the embodiment disclosed herein.
It should be appreciated that the pre-mold material provides a mechanical bond between the cable and connector, fully encapsulates conductors and wiring terminals to provide strain relief and secure wire terminations, insulates conductors and terminals to eliminate shorting between conductors and provides environmental sealing of the terminations to prevent infiltration of contaminants and also eliminates pushed pins because the pre-mold material fills the terminal housing, capturing the contacts and preventing them from being pushed back into the connector housing. Furthermore, although the over-mold material is preferably constructed from a thermoplastic vulcanizate (TPV) (such as, but not limited to Santoprene® TPV) or thermoplastic elastomer (TPE) material, it is contemplated that the over-mold material may be any type of material that is flexible, absorbs impact and that protects the internal conductors while also providing resistance to a wide variety of chemicals (some materials for example may include thermoplastic polymers (i.e. polyethylene, polypropylene), styrenic block copolymers, polyolefin blends, elasatomeric alloys, thermoplastic polyurethanes, thermoplastic copolyester, thermoplastic ployamides, etc.). And because the over-mold material covers a portion of the associated cabling, the over-mold material also advantageously provides a flexible strain relief that improves the flex life of the cable and prevents premature wear and damage to the cable jacket. Accordingly, over-mold material advantageously assists the electrical connector 100 in having an ergonomic design which provides a firm gripping surface for mating and safe handling of connectors and allows for an optional custom molded logo insert to provide a customer's logo/identification on the connector. Moreover, the over-mold allows for molded-in arrows on the connector to assist with the correct alignment for easy mating and molded-in connector information for easy reference and identification.
Referring to
The strain relief 300 includes a plurality of slots 304 distributed along the length of the strain relief 300 and partially around the circumference of the strain relief. The plurality of slots 304 are configured in slot pairs having a first slot 308 and a second slot 310 and are located such that for each slot 308, 310 located along the length of the strain relief 300, there is a corresponding slot 310, 308 located on the opposing side of the strain relief 300. It should be appreciated that each of the slots 308, 310 are configured to extend partially along the circumference of the strain relief 300 to be separated from the slot 310, 308 on the opposing side of the strain relief by a body portion 312 of the strain relief 300. Furthermore, each of the slot pairs 308, 310 along the length of the strain relief 300 is offset from the adjacent slot pair 308, 310 along the circumference of the strain relief 300 by 90°. It should be appreciated that the slot pairs 308, 310 may be distributed equally along the length of the strain relief 300 or they may be distributed along the length of the strain relief 300 to focus on desired stress points (for example, near the beginning/ends of the strain relief 300). Moreover, each of the slots 308, 310 include a slot width SW, a slot length SL and a slot depth SD, wherein the slot width SW ranges from about 1/10 to 1/25 of the length of the strain relief 300 and the slot length is approximately equal to the diameter of the strain relief. It should be appreciated that the strain relief diameter (SRD) is approximately equal to 1.2 to 1.5 times the cable diameter CD, as desired. Thus, an approximate size of the strain relief diameter SRD can be expressed as:
SRD=CD*(1.35±0.15).
Moreover, because in an exemplary embodiment the slots 304 have a slot depth SD down to the jacket of the cable, it follows that an approximate size of the slot depth SD can be expressed as:
SD=(SRD−CD)/2±0.25.
It should be appreciated as the cable 302 is bent, relative to the electrical connector 100, the strain relief 300 advantageously works to distribute and limit the strain on the connection between the cable 302 and the connector 100. Another advantage is that because the strain relief 300 is constructed from the over-mold material, it resists harsh and environments and there are no metal shards or wires to break and cause injury to cable handlers like the Kellems grip. This is because as the cable 302 is being bent, the slots 304 on the side of the strain relief 300 in the direction of the bend are being compressed so that eventually a portion of the slot sides will contact each other. Simultaneously, the slots 304 on the side of the strain relief 300 in the opposing direction of the bend are being stretched so that the sides of the slots are pulled away from each other. Thus, the bending forces are being directed to the outer corners of the slots on the side in the direction of the bend and to the inner corners (i.e. near the cable) of the slots on the side in the direction opposite of the bend.
Referring to
Regarding the determination of the minimum bend radius (MBR) of the cable 302, the MBR may be determined by referring to acceptable standards (e.g. National Electrical Code (NEC) articles 300-34, 334-11 and 336-16) or the Insulated Cable Engineers Association (ICEA)) or the MBR may be determined via calculation (for example, MBR=6*D, where D is the diameter of the cable 302). It should be appreciated that the minimum bend radius may also be dependent upon the specific cable being used.
It is known that the minimum bend radius (MBR) is usually expressed as multiples of the wire diameter and is typically measured relative to the inside curvature of the cable or wire that is being bent. The MBR typically refers to the approximate limit that a cable 302 can be bent without kinking it, damaging it or shortening its life. Thus, it stands to reason that the smaller the MBR, the more flexible the cable 302. Referring to
It should be appreciated that the slot width SW, the slot length SL and/or the slot depth SD may be chosen to give the strain relief more or less support and pliability as desired or based on application and/or to enhance the tactile feel of the electrical connector 100. It should also be appreciated that the novel and unique configuration of the slots of the strain relief 300, 600 provide superior strain relief protection, while helping to provide for an electrical connector that is more aesthetically pleasing, user friendly (with a more pleasant and easy to use feel), durable, electrically insulated, and flexible. It should also be appreciated that although as described herein, the slot depth SD is shown as going down to the cable jacket, it is contemplated that slot depths SD that do not go all the way down to the cable jacket may also be used. For example, a slot depth SD that only goes half way to the cable jacket provides for a strain relief that does not bend as easy and thus, provides more protection and a more rigid feel. As such, the slot depth SD may be chosen as desired (such as for greater/lesser flexibility and/or relief). This may be desirable for cables assemblies having smaller diameters and that are subject to more applications that include repeated bending and unbending.
Referring to
Referring to
Furthermore, it should be appreciated that the electrical connector of the present invention (male and female) are fully qualified to MIL-DTL-22992 standards with the following tests: Di-electric Voltage Withstand, Insulation Resistance Test, Submersion Test, Drop Test and Cable Pull Force. Accordingly, the connector in accordance with the present invention maintains the required conductive coating and continuity from shell to ground per MIL-DTL-22992 as well as Environmental Rating—Watertight per MIL-DTL-22992.
It should be appreciated that the present invention may be used for any field of technology that employs cables and also may include other embodiments that are also applicable in any field of technology that employs cables. For example, the present invention may be used for connectors prevalent in the fiber optic, medical, industrial, geological and/or the entertainment fields. Furthermore, it should be appreciated that the sizes and dimensions as disclosed herein are given in inches and are not meant to be limiting. Rather the invention is meant to include various other sizes and units as desired and as suitable to the desired end purpose.
Moreover, it should be appreciated that each of the elements of the present invention may be implemented in part, or in whole, in any order suitable to the desired end purpose. In accordance with an exemplary embodiment, the processing required to practice the method of the present invention, either in whole or in part, may be implemented, wholly or partially, by a controller operating in response to a machine-readable computer program. In order to perform the prescribed functions and desired processing, as well as the computations therefore (e.g. execution control algorithm(s), the control processes prescribed herein, and the like), the controller may include, but not be limited to, a processor(s), computer(s), memory, storage, register(s), timing, interrupt(s), communication interface(s), and input/output signal interface(s), as well as combination comprising at least one of the foregoing. It should also be appreciated that the embodiments disclosed herein are for illustrative purposes only and include only some of the possible embodiments contemplated by the present invention.
While the invention has been described with reference to an exemplary embodiment, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated any use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.
This application is related to U.S. Non-Provisional patent application Ser. No. 13/590,918 and claims benefit of the filing date of U.S. Provisional Patent Application Ser. No. 61/580,050, filed Dec. 23, 2011, the contents of both of which are incorporated by reference herein in their entirety.
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| Number | Date | Country | |
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| 61580050 | Dec 2011 | US |
