Method and apparatus for grounding and mounting a high amperage single pole connector

A combination grounding/mounting connector and method for mounting an electrical receptacle adapted to receive an electrical current carrying cable connector to a panel. The combination grounding/mounting connector device includes a first portion passing through an aperture formed in the receptacle and the panel for engaging a device for securing the electrical receptacle to the panel, the first portion accommodating connection to an electrical ground; and, a second portion providing an electrical ground connector when the first portion is connected to an electrical ground.

BACKGROUND

Currently it is desirable for an improved electrical grounding apparatus and method for electronic systems and circuits at field installations in harsh industrial environments, e.g. an oil production rig, and the like, where there is need for secure, rugged equipment. An electrical grounding application for industrial applications employing high amperage cables and connections are typically satisfied by the provision of a grounding system, typically provided or located at a system panel receiving high-amperage cable connector.

FIG. 1depicts a current grounding system10at a system panel or like panel or backboard device15receiving high amperage cable connector receptacles12used for coupling single pole electrical cable connectors. For example, the receptacle12depicted inFIG. 1may be a panel mounted cable connector receptacle product including a cast-aluminum housing and a mounting base13shown, in the form of a square plate, having mounting apertures17a,17b,17c,17din respective corners. A threaded mounting screw or bolt14a, . . .14dpasses through each respective aperture and complementary threaded nuts (not shown) are used to fixedly mount the base portion13of the receptacle to the panel or backboard15.

As shown inFIG. 1, one current grounding system solution20, employs a conductive structure, e.g., a cable20cand male grounding plug or pin20athat may be coupled to a separate connection point, a female receptacle20b, that is affixed to or integrally formed in or on the surface of the enclosure panel15and disposed to receive male grounding plug20afor electrical coupling of a device connected to cable20cto the ground. Thus, as shown inFIG. 1, underside panel15, a further conductor couples or fastens the grounding receptacle20bto electrical ground (earth). The existing solution requires more labor (i.e., during field installation) and a larger panel footprint area since the panel must accommodate both the mounted receptacle in addition to the location of the female grounding plug receptacles20bformed on the panel in proximity with the receptacle12and taking up valuable panel real-estate.

Moreover, in current implementations, the conductor/cabling and pin20aused as a grounding connection to the female ground connector receptacle20bis slip-fit onto the female grounding receptacle, and can become easily disconnected by excessive vibrations and disturbances in harsh environmental and operating environments.

SUMMARY

A connector device used for mounting a first object to another object, and further which connector is configured to connect to an electrical ground.

In one embodiment, there is provided a conductive electrical grounding connector comprising a body including: a first portion adapted to mount an electrical device to a surface, the first portion is threaded and adapted to receive an electrical ground lug and fastener; and a second portion adapted to mate with a mating connector, the second portion is a single-pole connector where the single pole connector is one of a single-pole cam connector and a single pole non-cam connector

In a further embodiment, there is provided a grounding system for a cable sheath. The grounding system comprising: a grounding connector disposed to mount an electrical connector receptacle to a surface, the grounding connector having a portion disposed to extend through at least a portion of the connector receptacle to engage a fastener to fixedly mount the electrical connector receptacle to the surface, and adapted to couple to an electrical ground, the grounding connector including an electrical ground contact portion; and, a grounding cable configured to electrically connect the cable sheath to the electrical ground contact portion.

Further, in accordance with this further embodiment, there is provided a method for grounding a cable sheath of a cable. The method comprises: affixing an electrical connector to a surface with a connector; placing an electrical ground lug over the a first portion of the connector; threading a nut onto the first portion of the connector to secure the electrical ground lug to the connector; connecting a cable sheath to a single-pole connector; and mating the single-pole connector to a second portion of the connector.

In each of these embodiments, the electrical ground contact of the combination grounding and mounting connector device provides a single pole male contact structure designed to mate with a cam-action single pole type female electrical connector. Alternately, the electrical ground contact provides a male contact structure designed to mate with a non-cam single pole type female electrical connector. Both the cam or a non-cam type electrical connector may be employed in the grounding system.

DETAILED DESCRIPTION

FIG. 2illustrates a high amperage cable connector receptacle12shown mounted to a panel15in accordance with the invention. As shown inFIG. 2, the base portion13of the cable connector receptacle12includes four threaded mounting apertures (holes)17a,17b,17c,17dwhich receive a respective receptacle housing mounting screw or bolt for mating the receptacle12to the panel15. According to an embodiment of the invention, one mounting screw or bolt75shown encircled in broken lines associated with one mounting aperture17dinFIG. 2, functions as a combination mounting bolt and grounding member (connector). That is, mounting/grounding bolt75functions not only to mount the receptacle base portion13to the grounded panel15, but provides a grounding contact structure for any grounding application. For example, in one embodiment, the grounding contact enables secure connection for grounding of the cable sheath of a high amperage cable connector received by the receptacle12in the manner as will be explained in greater detail herein. While the description herein refers to mounting an electrical cable receptacle, it is understood that any like housing or structure for an device, electrical or otherwise, may be mounted using the combination mounting bolt and grounding member of the present invention.

By way of a non-limiting example, receptacle12includes a male or female single pole electrical connection dimensioned to mate with a corresponding female or male single pole connector device used for connecting electrical cabling of various sizes to a panel or housing. In one exemplary embodiment, such a male or female panel mounted receptacle mates with a corresponding female or male single pole connector device (such as an 1135 Amp single pole electrical connector) designed for mating cables sizes used for applications up to or exceeding the application for which they are intended. An example of such a rating is 1000 Volts AC or DC and up to 1135 amps continuous duty.

In the manner as now described herein below, an area of the mounting panel15reserved for locating a ground lug of the prior art grounding system of a high amperage cable connector is eliminated.

FIG. 3shows a schematic of the mounting/grounding member75in one embodiment of the invention. The mounting/grounding member75is of unitary construction (although it does not have to be unitary construction), and, in one embodiment, comprises a conductive metal bolt.

As shown inFIG. 2and the detailed view of combination grounding/mounting member75shown inFIG. 3, in one embodiment, combination grounding/mounting member75received within a receptacle aperture, e.g., aperture17d, includes a first threaded portion81of length sufficient to extend beneath the underside of panel15for threaded engagement with suitable mounting assembly90, e.g., heavy duty back nut(s), locking nut and washer(s), or some combination thereof, which engage threads of threaded first portion81for mounting non-conductive mounting base portion13of the receptacle12to panel15. First portion81of member75is threaded having a length greater than at least the thickness of the aperture formed in the receptacle mounting base aperture and panel when the receptacle mounting base is fixedly secured to the panel.

In one embodiment, combination grounding/mounting member75includes a second connector portion87that extends above the receptacle base portion when the receptacle is mounted to the panel by mounting assembly90and includes flanged portion82that abuts the surface of the base portion of the receptacle when secured to the panel. This second connector portion87extending above the panel forms a male grounding contact when the mounting/grounding member75is coupled to electric ground underside the panel, for instance, by crimping or fastening a ground conductor lug or similar device45to first connection portion81of mounting/grounding member75underside the panel to an electrical ground (earth) as shown inFIG. 6. In this manner, the panel also becomes grounded. Although the second connector portion87extending above the panel forms a male grounding contact in the present embodiment, it can alternatively form a female grounding contact in another embodiment.

In one embodiment, as shown in a top plan view ofFIG. 4A, taken along line A-A ofFIG. 3, the male grounded contact87includes a top portion having a lead-in cam surface92, e.g., a cutaway or flat surface, such that, the second connector portion65of mating device60shown inFIG. 6, provides a cam fit, such as by turning the second connector portion65to engage male grounded contact87. That is, the female connector of second connector portion65includes a cylinder or cylindrical type structure having a protuberance or raised pin (not shown) on an inside surface thereof adapted to slide fit along the flat92of grounding contact87to the location of a groove (not shown) whereupon a simple rotation brings the protuberance into a groove at a circumferential position from which it cannot be directly withdrawn without rotation, thus forming a cam action-type lock.

In an alternate embodiment, as shown in a top plan view ofFIG. 4B, the combination grounding/mounting member75includes a male grounded contact87′ that does not include a cam surface, i.e., the second connector portion65of mating device60provides a non-cam or slide-in or insertion fit to the top portion of grounding contact87′.

In both embodiments, the male grounded contact87having a cammed contact surface92depicted inFIG. 4A, or having a non-cam contact surface in the case of grounded contact87′ depicted inFIG. 4B, there is provided a bifurcation in the form of a slot95to ensure provision of adequate (spring) pressure against the inside the female connector65.

FIG. 5illustrates an alternate embodiment of the combination mounting/grounding connector shown inFIG. 3. In this alternate embodiment of the invention shown inFIG. 5, mounting/grounding member75′ is of like length dimension of mounting/grounding member75ofFIG. 3, however, includes a shorter threaded first portion81′ designed to protrude the underside of the panel when fitted within receptacle mounting base aperture. Member75′ includes a non-threaded, cylindrical middle portion85of having a length commensurate with at least the thickness of the aperture formed in the receptacle mounting base aperture and panel when the receptacle mounting base is fixedly secured to the panel and, defines a male grounded contact86having a thicker diameter than that of non-threaded middle portion85to thereby abut against the surface of the receptacle mounting base when mounted to a panel.

As further depicted inFIG. 5, alternate member75′ provides a male grounded contact portion87′ having a non-cam surface as in the embodiment depicted inFIG. 4B, or, alternately the male grounded contact portion87has a cam surface92as in the alternate embodiment depicted inFIG. 4A. Further, male grounded contact87is provided with a bifurcation in the form of a slot95to provide a pressure fit within the inside the female connector65when engaged to ground a cable sleeve or sheath.

FIG. 6is a transparent three-dimensional view of a grounding system or assembly50including a mating connector60for connecting, in an exemplary embodiment, a high amperage cable sheath, to a grounded contact portion of the combination mounting/grounding connector of the invention provided at the panel receptacle. The mating connector60according to an embodiment of the present invention, connects with the sleeve or sheath of a high amperage current carrying cable received at connector receptacle10and is electrically grounded via the mating connection to the grounded contact portion87/87′ of a grounding/mounting member75(FIG. 3) or, the grounding/mounting member75′ (FIG. 5).FIG. 6further depicts the mating assembly60connected to grounding contact portion87of the mounting/grounding member75′. As shown inFIG. 6, in one embodiment, the grounding assembly60for grounding the cable sheath includes a flexible grounding cable63(e.g., a # 3 or # 4 AWG wire) including a portion62, configured to physically engage an insulating sheath or sleeve of a cable (e.g., a high amperage cable). For example, in one embodiment, first connector portion62connects to a high amperage cable sleeve or sheath as follows: the flexible grounding cable63is first connected, e.g., adhered such as by electrical tape and/or wrapped together with a heat shrink tube, to the high amperage cable. At or near an end of the adhered flexible grounding cable63, a portion of the high amperage cable is exposed, e.g., by cutting back the outer sheath of jacket of the high amperage cable to expose a pre-determined length if the insulative braided armor shielding, for instance.FIG. 7illustrates a length of exposed braided armor shielding101of the high amperage cable150. Then, the grounding cable63is cut to remove a portion of its insulative jacket to expose grounding cable wire strands115at a length sufficient to wrap around the exposed braided armor shielding101. These strands115are then tightly wrapped around the jacket-braided armor shielding101and soldered or otherwise affixed to the insulative braided armor shielding, e.g., at solder points105. An electrical tape, rubber or other material tape125may be used to wrap the finished connection and the grounding cable strands115against the main high amperage cable. Optionally, or in addition, the heat shrink wrap may be provided over the taped connection and heated in place. Other embodiments, may entail embedding a conductive lug connected to the flexible grounding cable in the surrounding cable sheath so as to contact the braided armor shielding. In either embodiment, the connector grounding cable63includes a termination portion65designed to mate with the grounding/mounting connector.

Particularly, the termination portion65of grounding assembly60for grounding the cable sheath includes, in one embodiment, a female connector66designed to electrically couple to the male grounded contact87,87′ of mounting/grounding member75,75′. In one embodiment, as shown inFIG. 6, when intended for use in high power conditioning and power transfer applications, such as required for the oil rig, advantageous grounding of the sheath is accomplished by simply coupling the single pole non-cam (or cam-type in an alternate embodiment) female connector66(such as the aforementioned 1135 Amp single pole single pole cam or non-cam electrical connector product) to the respective male grounded contact87(depicted inFIG. 4A) by a simple rotation manipulation52(as shown by the arrow), or to the alternate male grounded contact87′ (depicted inFIG. 4B) by a simple insertion manipulation54.

It is understood that in either embodiment, whether the female connector66is a single pole cam or non-cam type connector manipulated to fit a respective male grounded contact87in a first embodiment depicted inFIG. 4A, or alternate male grounded contact87′ depicted inFIG. 4B, a secure electrical ground connection that is more resistant to vibrations and noise is formed.

Thus, in one application, by use of the invention, electrical grounding needs of a high amperage cable's insulating sleeve or sheath is satisfied, especially at field installations in harsh industrial environments, e.g. an oil production rig, where there is need for secure, rugged equipment. For example, oil rig installations include electrical generation equipment, e.g., generators that provide power to electro-mechanical assemblies including, but not limited to: top drive motor(s) and mud pump(s), and include other power signal conditioning equipment, e.g., silicon controlled rectifier (SCR) drives, typically housed in an enclosure, that perform AC to DC power conversion. Such drive equipment typically includes banks of male or female panel mounted receptacles each bolt-mounted to the panel as shown inFIG. 1and receiving a high power cable connector. Insulating sleeve and sheath grounding solutions can be employed by use of the present invention to mitigate electrical disturbances caused by the high power electrical generation and signal conditioning equipment that are a source of unwanted electrical interference including harmonics and distortion on the power cable lines found to cause interference (feedback and noise) in the sensitive control electronics controlling the operation of the drive and pump motors.

Though the combination grounding/mounting connector (bolt) of the invention has been shown and described for mounting the high amperage connector receptacle10to a panel or backboard, it is understood that the combination grounding/mounting connector can be used in any electrical apparatus. In the embodiments illustrated, the combination grounding/mounting connector is designed to replace one of the mounting bolts typically used in the field. By using an embodiment of this invention, the grounding of the sheath of a high amperage cable doesn't take up any additional space on the panel and the connection can be made simply and quickly without the need for any additional hardwiring.

The present invention can be used for mounting panel mounted receptacles that accommodate a electrical cable connection primarily for AC to DC power conversion and power transfer, e.g., from the electrical generator to power motors and drives of large electro-mechanical assemblies, e.g., in oil rigs, nuclear plants, power distribution facilities or plants, amusement parks, carnivals, or any application where there is needed a mobile unit for high power distribution or power transfer.

Thus, in a further aspect of the invention, there is provided a grounding system and method for providing a grounding system for panel mounted receptacles that accommodate an electrical cable connection. More particularly, the method of the present invention enables the grounding of a cable sheath of a high current carrying cable. The method includes: affixing an electrical connector to a panel with a connector; coupling a first portion of said connector to an electrical ground; electrically connecting a cable sheath of the high current carrying cable received at the electrical connector for receipt at a top portion of the grounded connector.

The electrically connecting of the high current carrying cable to a top portion of the grounded connector via the flexible grounding cable having a terminating female mating connector includes rotating the female connector to form a cam action lock with the connector top portion. Alternately, the electrically connecting of the high current carrying cable to a top portion of the grounded connector via the flexible grounding cable having a terminating female mating connector includes fitting said female connector to the top portion.