Patent Grant
7210947
None
The present invention generally relates to electrically grounded connectors, and more specifically, to a cable harness system, ground clips and a method for electrically grounding a conductor of the cable harness system.
Electric power systems are designed to generate, transmit and distribute electrical energy to loads. In order to accomplish this, power systems generally include a variety of power system elements such as electrical generators, electrical motors, power transformers, power transmission lines, buses and capacitors, to name a few. As a result, power systems typically include protective devices and associated procedures to protect the power system elements from abnormal conditions such as electrical short circuits, overloads, frequency excursions, voltage fluctuations, and the like.
Electric power systems also require communication and computer networks. For example, Supervisory Control and Data Acquisition (SCADA) systems are included to measure the voltages associated with a power system substation bus (i.e., bus voltages), to measure the current coming into the bus from a power transmission line (i.e., a line current), and to measure the status or position of numerous switches in the substation. The status measurements may include indications of circuit breaker positions and electrical power routing switch positions (e.g., open position, closed position). The SCADA system may also be configured to transmit the current, voltage and switch position measurements to a central control center (CC) via a SCADA communication network for review by an operator. The operator can then make decisions such as closing a circuit breaker to enable additional electric power to a particular load. In that case, a command from the operator delivered via the SCADA communication network results in closure of the circuit breaker.
Such communication and computer networks include the use of cabling, connectors and associated grounding methods. As a result, equipment manufacturers in the power system industry are engaged in manufacturing the cable/connector assemblies supporting the communication and computer networks. One typical method for manufacturing and connecting a cable having a number of conductors (e.g., a multi-conductor cable used with a DB-9 connector) includes stripping and soldering one of the cable conductors, designated as a ground wire, directly to a conductive shell, or body, of an associated connector. Besides being somewhat labor intensive, electrical grounding via use of a solder connection to the connector shell limits the type of conductor shells that can be used. Alternatively, another method for grounding a cable having a number of conductors includes use of metal backshells configured to provide grounding from the wire to the case. Unfortunately, such metal backshells are expensive and often labor intensive and complicated to assemble.
In accordance with an aspect of the invention, a cable harness system includes a cable having a number of individual conductors, and a connector to enable conductive coupling of the cable to a device. The connector includes an electrically conductive connector body configured for attachment to a chassis of the device. The cable harness system also includes a ground clip to facilitate an electrical ground path between one of the individual conductors and the chassis of the device. The ground clip includes a first portion configured for conductive coupling (e.g., a connection barrel having a bore formed therein) to the conductor, and a second portion configured for conductive contact (e.g., a contact flange) with the connector body.
In accordance with another aspect of the invention, a ground clip facilitates an electrical ground path between a conductor of a number of individual conductors of a cable and an electrically conductive connector body of a connector. The connector body is attached to a chassis of a device. The ground clip includes a first portion configured to conductively couple to the conductor, and a second portion configured to conductively contact with the connector body. The ground clip may be configured as a ground clip lug captured by a captive screw member compressively securing the ground clip lug against the connector body. The ground clip may also be a ground clip bracket configured for frictional engagement with the connector body.
In accordance with a further aspect of the invention, a method facilitates an electrical ground path between a conductor of a number of individual conductors of a cable and an electrically conductive connector body of a connector. The connector body is attached to a chassis of a device. The method includes conductively coupling the conductor to a ground clip via a first portion of the ground clip, and conductively connecting the second portion of the ground clip to the connector body. The method also includes securing the ground clip against the connector body.
It should be understood that the present invention includes a number of different aspects and/or features which may have utility alone and/or in combination with other aspects or features. Accordingly, this summary is not an exhaustive identification of each such aspect or feature that is now or may hereafter be claimed, but represents an overview of certain aspects of the present invention to assist in understanding the more detailed description that follows. The scope of the invention is not limited to the specific embodiments described below, but is set forth in the claims now or hereafter filed.
In addition to the cable 20, the typical cable harness system 10a includes a backshell 52 configured to house an extending portion of the connector 50 that includes the connector contact holes 40. An opening in the backshell 52 accommodates placement of the cable 20 when the conductor contacts 30 are inserted into respective connector contact holes 40. Although only a bottom portion is shown, it should be understood that the backshell 52 includes a corresponding top portion.
The conductive connector body 56 includes a connector flange 58 having dual device attachment holes 54 formed therein. The dual device attachment holes 54 in the connector flange are positioned to enable alignment and retainment of the connector 50 to its corresponding connection mate 62 on a device chassis 60.
In the illustrated example, a captive screw member 36, also know as a jackscrew, is inserted through a respective dual device attachment hole 54 and then screwed into a corresponding threaded nut 64 on the device chassis 60, thereby compressively securing the connector 50 to the device chassis 60. The cable 20 is therefore electrically grounded via the solder joint 28 between the stripped conductor 26 in contact with the conductive connector body 56 secured to the device chassis 60. While providing an effective electrical ground path, construction of the solder joint is labor intensive and time consuming. In addition, the step of constructing the solder joint may not fit well within an associated manufacturing process.
Referring to
The conductor 26 is conductively connected to a first end of the connector contact 32 using a solder connection or a crimped connection. A second end of the connector contact 32, which may be configured as a male or female contact, is preferably held within the bore 78 via a friction fit. The second end of the connector contact 32 may also be held within the bore 78 via a solder connection or a crimped connection.
In some cases, it may be advantageous to insert the conductor 26 directly into the bore 78.
The ground clip bracket 80a includes a first portion configured for electrically conductive coupling to the conductor 24, and a second portion configured for electrically conductive contact with the conductive connector body 56. Although preferably connected via a connector contact 32, a crimped connection, the conductor 24 may also be connected to the first portion of the ground clip bracket 80a via a soldered connection.
The bracket base 81 includes an opening 90 formed therein to accommodate insertion of an extending portion of the connector 50. Each of the pair of arms 84 is inclined towards the other arm to frictionally engage the extending portion of the connector 50 in order to enable electrical grounding of the cable when the connector body 56 is conductively attached to the device chassis 60. Optionally included in the bracket base 81 is a pair of apertures 86, 88 configured to permit used of a corresponding pair of captive screw members 36 to compressively secure the connector body 56 against the device chassis 60.
In some applications, it may be desirable to utilize a printed circuit board in the cable harness. Such applications may include cables used in signal processing applications such as those that adapt between communication standards.
While this invention has been described with reference to certain illustrative aspects, it will be understood that this description shall not be construed in a limiting sense. Rather, various changes and modifications can be made to the illustrative embodiments without departing from the true spirit, central characteristics and scope of the invention, including those combinations of features that are individually disclosed or claimed herein. Furthermore, it will be appreciated that any such changes and modifications will be recognized by those skilled in the art as an equivalent to one or more elements of the following claims, and shall be covered by such claims to the fullest extent permitted by law.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5267878 | Shinji et al. | Dec 1993 | A |
| 5315063 | Auclair | May 1994 | A |
| 6217381 | Kameyama | Apr 2001 | B1 |
| 6230406 | Balfour et al. | May 2001 | B1 |
| 6437245 | Hayashi | Aug 2002 | B1 |
| 6595789 | Oota et al. | Jul 2003 | B2 |
| 6669511 | Yagi et al. | Dec 2003 | B1 |
