ELECTRICAL FITTING INCORPORATING EQUIPMENT GROUND IN CONNECTION WITH TWO-WIRE AND THREE-WIRE RECEPTACLES

• US 3,739,317 A
• Filed: 10/12/1971
• Issued: 06/12/1973
• Est. Priority Date: 10/12/1971
• Status: Expired due to Term

• Current Assignee: Melvin Wise
• Original Assignee: Melvin Wise
• Inventors: Wise, Melvin
• Primary Examiner(s): Champion, Marvin A.
• Assistant Examiner(s): Hafer, Robert A.
• Application Number:
  US05/188,237
• Time in Patent Office: 609 Days
• Field of Search: 339/14R,14P,31,32,33,195,196,14RP
• US Class Current: 439/103
• CPC Class Codes: H01R 27/00 Coupling parts adapted for co-operation with two or more dissimilar counterparts for dissimilar contact members H01R13/35; supported only by co-operation with a counterpart H01R31/00; with a holder adapted for supporting apparatus to which its counterpart is attached H01R33/90

Abstract

An electrical fitting which can be selectively connected to either a three-wire receptacle or a two-wire receptacle by reorientation of the ground male element within the fitting. An equipment ground connection is also established during selective connection between the electrical fitting and either the threewire receptacle or the two-wire receptacle.

Claims

1. An electrical fitting comprising a body, a pair of male elements carried by said body with each being of a configuration and orientation within said body permitting connective reception in complementary conductor female elements of either a two-wire or three-wire receptacle, a third male ground element carried by said body being removably affixed to said body selectively in a first position and while so affixed is electrically connected to ground within said electrical fitting and oriented within said body to permit connective reception in the complementary female ground element of said three-wire receptacle;

said body having a configuration defining an aperture with a recessed portion within said body extending generally in a direction parallel to the longitudinal axis of said third male ground element when in said first position within said body, said aperture being on the face portion of said electrical fitting which is opposite an electrically conductive fastener holding the cover plate of said two-wire receptacle during connective reception of said electrical fitting with said two-wire receptacle, that portion of said body defining said recessed portion being electrically connected to ground and of a configuration allowing said third male ground element to be selectively contained and grounded therein in a second oriented position permitting selective connection of said electrical fitting to said two-wire receptacle, said third male ground element in said second oriented position with an end portion thereof in abutment with said fastener of said cover plate of said two-wire receptacle during connective reception of said complementary pair of male and female elements, said abutment completing an electrical ground connection between said electrical fitting and said twowire receptacle.

2. The structure of claim 1 wherein said end portion of said third male ground element which abutts said fastener is comprised of a material having magnetic properties;

said end portion magnetically attracting said fastener when said fastener is comprised of magnetically attractive material and thereby maintaining a close physical and electrical contact between said third male ground element and said fastener.

3. An electrical fitting comprising a body, a pair of male elements carried by said body with each being of a configuration and orientation within said body permitting connective reception in complementary conductor female elements of either a two-wire or three-wire receptacle, a third male ground element carried by said body being of a configuration and in a first oriented position permitting connective reception in the complementary female ground element of said three-wire receptacle, said third male ground element being removably affixed and electrically connected with ground in a second oriented position in said body permitting selective connection of said electrical fitting to said two-wire receptacle, said third male ground element being aligned in said second oriented position in said body with an end portion of said third male ground element abutting an electrically conductive fastener holding the cover plate of said two-wire receptaclE during connective reception of said electrical fitting with said two-wire receptacle, said abutment completing an electrical ground connection between said electrical fitting and said two-wire receptacle, said end portion of said third male ground element which abuts said fastener being of a configuration defining an opening and recessed portion therein;

an electrically conductive spring-like device having one end retained within said recessed portion and being electrically grounded therein and the other end protruding beyond said end portion of said third male ground element, said protruding end compressed and exerting pressure on said fastener when abutting thereon and thereby maintaining a close physical and electrical contact between said third male ground element and said fastener.

4. The structure of claim 3 wherein said end portion of said third male ground element which abuts said fastener is comprised of a material having magnetic properties, said end portion magnetically attracting said fastener when said fastener is comprised of magnetically attractive material, the magnetic attraction and spring-like contact between the end portion of said third male ground element and said cover plate fastener provides a close physical and electrical contact between said third male ground element and said fastener when there is connective reception of said pair of said male elements of said electrical fitting and their complementary female elements in said two-wire receptacle.

5. An electrical fitting comprising a body, a pair of male elements carried by said body with each being of a configuration and orientation within said body permitting connective reception in complementary conductor female elements of either a two-wire or three-wire receptacle, a third male ground element carried by said body being of a configuration and in a first oriented position permitting connective reception in the complementary female ground element of said three-wire receptacle, said third male ground element being removably affixed and electrically connected with ground in a second oriented position in said body permitting selective connection of said electrical fitting to said two-wire receptacle, said third male ground element being aligned in said second oriented position in said body with an end portion of said third male ground element abutting an electrically conductive fastener holding the cover plate of said two-wire receptacle during connective reception of said electrical fitting with said two-wire receptacle, said abutment completing an electrical ground connection between said electrical fitting and said two-wire receptacle, said end portion of said third male ground element which abuts said cover plate fastener being of a configuration defining an opening and recessed portion therein;

a spring-like device having one end retained within said recessed portion, an electrically conductive plunger-like element having one end retained within said recessed portion and being electrically grounded therein and the other end having a head portion, said spring-like device exerting pressure against said plunger-like element tending to eject said head portion from said recessed portion and forcing said head portion in abutment under pressure against said fastener of said two-wire receptacle to provide a close physical and electrical contact between said third male ground element and said fastener when there is connective reception of said pair of said male elements of said electrical fitting and their complementary female elements in said two-wire receptacle.

6. The structure of claim 5 wherein said head portion of said plunger-like element is comprised of material having magnetic properties;

said head portion magnetically attracting said cover plate fastener when said fastener is comprised of magnetically attractive material, the combination of the pressure of said spring-like device against said plunger-like element and the magnetic attraction of said head portion providing a close physical aNd electrical contact between said third male ground element and said fastener when there is connective reception of said pair of said male elements of said electrical fitting and their complementary female elements in said two-wire receptacle.

7. An electrical fitting comprising a body, a pair of male elements carried by said body with each being of a configuration and orientation within said body permitting connective reception in complementary conductor female elements of either a two-wire or three-wire receptacle, a third male ground element carried by said body being of a configuration and in a first oriented position permitting connective reception in the complementary female ground element of said three-wire receptacle, said third male ground element being removably affixed and electrically connected with ground in a second oriented position in said body permitting selective connection of said electrical fitting to said two-wire receptacle;

said third male ground element selectively affixed within said body in said second oriented position with an end portion of said third male ground element abutting an electrically conductive fastener holding the cover plate of said two-wire receptacle during attachment of said electrical fitting to said two-wire receptacle, a spring-like device contained within said body and positioned to exert pressure against said third male ground element tending to project said third male ground element from said body and thrust it against said two-wire receptacle fastener thereby maintaining a close physical and electrical contact between said third male ground element and said fastener which is electrically connected to ground.

8. An electrical fitting comprising a body, a pair of male elements carried by said body with each being of a configuration and orientation within said body permitting connective reception in complementary conductor female elements of either a two-wire or three-wire receptacle, a third male ground element carried by said body being of a configuration and orientation permitting connective reception in a complementary female ground element of said three-wire receptacle;

said body having a configuration defining a first aperture and recessed portion therein oriented to receive insertion of said third male ground element within said body, said first recessed portion having an internal screw thread, said third male ground element having an end portion thereof containing an external screw thread compatible with the external screw thread of an electrically conductive fastener holding the cover plate of a two-wire receptacle and complementary to the internal screw thread of first recessed portion, said third male ground element being removably affixed to said body selectively in a first position by engagement of said external screw thread of said third male ground element with said complementary internal screw thread of said first recessed portion and while so affixed is electrically connected to ground within said electrical fitting and oriented within said body to permit connective reception in said complementary female ground element of said three-wire receptacle;

said body having a configuration defining a second aperture and recessed portion within said body extending generally in a direction parallel to the longitudinal axis of said third male ground element when in said first position within said body, said second aperture being on the face portion of said electrical fitting which is opposite said electrically conductive fastener holding said cover plate of said two-wire receptacle when said pair of male elements make connective reception with said complementary female elements of said two-wire receptacle, that portion of said body defining said second recessed portion being electrically connected to ground and of a configuration allowing the unthreaded portion of said third male ground element to be inserted therein in a sliding fit thru said second aperture;

said third male ground element removably affixed selectively In a second position replacing said fastener holding said cover plate of said two-wire receptacle, said external screw thread of said third male ground element engaging the complementary internal screw thread within said two-wire receptacle, said unthreaded portion of said third male ground element contained in a sliding fit within said second recessed portion within said body when said pair of male elements make connective reception with said complementary female elements of said two-wire receptacle to provide a close physical and electrical ground contact between said two-wire receptacle and said electrical fitting as well as providing a firm connection between said electrical fitting and said two-wire receptacle during connective reception thereof.

9. The structure of claim 8 wherein said third male ground element contains a ridge of material adjacent said external screw thread thereon, said ridge of material abutting said cover plate and holding said cover plate to said two-wire receptacle when said third male ground element is selectively removably affixed in said second position replacing said conductive fastener holding said cover plate.

10. The structure of claim 8 wherein said third male ground element contains a ridge of material adjacent said external screw thread thereon, said body of said electrical fitting defining a depressed portion on the face portion thereof through which said third male ground element protrudes when selectively affixed in said first position, said ridge of material contained within said depressed portion when said third male ground element is in said first position and said electrical fitting is in connective reception with said three-wire receptacle;

said third male ground element selectively affixed in said second position replacing said fastener holding said cover plate of said two-wire receptacle, said ridge of material abutting said cover plate thereby holding said cover plate to said two-wire receptacle, said body defining a depressed portion on the face portion thereof where said second aperture is defined, said ridge of material contained within this said depressed portion when said third male ground element is in said second position and said electrical fitting is in connective reception with said two-wire receptacle.

11. An electrical fitting comprising a body, a pair of male elements carried by said body with each being of a configuration and orientation within said body permitting connective reception in complementary conductor female elements of either a two-wire or three-wire receptacle, a third male ground element carried by said body being of a configuration and orientation permitting connective reception in a complementary female ground element of said three-wire receptacle;

a face portion of said body through which said pair of male elements and said third male ground element project, said face portion containing a depressed portion therein encompassing the area through which said third male ground element protrudes and continuing away from said pair of said male elements, said depressed portion creating an access opening to a segment of said third male ground member when said electrical fitting is selectively plugged into either a two-wire or three-wire receptacle, said body being of a configuration defining an aperture and recessed portion therein oriented to receive insertion of said third male ground element within said body from its extended position, stopping means within said recessed portion to engage said third male ground element and prevent ejection from said recessed portion;

said third male ground member selectively prOjecting from said recessed portion in either of several positions, a first projected position permitting connective reception of said third male ground member with said complementary female ground element of said three-wire receptacle, said third male ground element having indentations on its external surface, an external fastening means having a configuration permitting it to be affIxed unto said third male ground element by engagement with a first of said indentations, said first indentation on third male ground element in said first projected position located on a segment thereof lying within said depressed portion of said face, said third male ground element being restrained from retracting from said first projected position into said recessed portion by said external fastening means affixed thereto within said depressed portion of said face by engagement with said first indentation and having a surface of said external fastening means making abutting contact with said body of said electrical fitting;

a second projected position of said third male ground element permitting connective reception of said electrical fitting with said two-wire receptacle, said third male ground element being retracted within said recessed portion of said body to allow connective reception of said male elements of said electrical fitting with said complementary conductor female elements of said two-wire receptacle, an electrically conductive external fastening means having a configuration permitting it to be affixed onto said third male ground element by engagement with a second of said indentations located on a front portion of said third male ground element lying within said depressed portion of said face upon said electrical fitting being in connective reception with said two-wire receptacle, a surface of said electrically conductive external fastening means being of a configuration to make abutting contact with an electrically conductive fastener holding the cover plate of said two-wire receptacle to complete an electrical ground connection from said third male ground element thru said electrically conductive external fastening means and thru said conductive cover plate fastener.

12. The structure of claim 11 wherein a spring-like device is contained within said recessed portion, said spring-like device exerting pressure against said third male ground element which tends to project said third male ground element from said body and consequently thrust said attached electrical conductive external fastening means into abuttment under pressure with said electrically conductive fastener holding the cover plate of said two-wire receptacle to complete the electrical ground connection.

13. The structure of claim 11 wherein said electrical conductive external fastening means has a surface defining a groove-like opening, said groove-like opening being on that portion of the surface of said external fastening means which is opposite said electrically conductive fastener holding said cover plate of said two-wire receptacle when in an abutting position thereon and continuing to an opening on a side and edge portion thereof, said external fastening means capable of being rotated about the longitudinal axis of said third male ground element at the point of engagement with said indentation thereon, said external fastening means rotated about said axis and said groove oriented to encompass a partially exposed portion of said cover plate fastener immediately adjacent to and lying between the head portion thereof and said cover plate, said cover plate fastener when selectively in a tightened position firmly engages said surface defining said groove-like opening between said head portion of said cover plate fastener and said cover plate thereby holding said external fastening means in both tight mechanical and electrical contact to complete the electrical ground connection.

14. An electrical fitting comprising a body, a pair of male elements carried by said body with each being of a configuration and orientation within said body permitting connective reception in complementary conductor female elements of either a two-wire or three-wire receptacle, a third male grOund element carried by said body being of a configuration and orientation permitting connective reception in a complementary female ground element of said three-wire receptacle;

said body having a configuratioN defining a first aperature and recessed portion therein oriented to receive insertion of said third male ground element within said body, said body having a configuration defining a hollowed out section adjacent said first recessed portion and separated therefrom by a layer of material of said body defining said first recessed portion, said hollowed out section lying in a direction away from said pair of male elements, a first spring-like device within said hollowed out section, said first spring-like device having an end portion affixed to said body at a point on the surface defining said hollowed out section away from said first recessed portion and the opposite end portion of said first spring-like device extended through an opening defined within said layer of material and protruding into said recessed portion;

said third male ground element having an indentation on its external surface, said third male ground element selectively oriented in said recessed portion in either of several positions, a first extended position permitting connective reception of said third male ground element with said complementary female ground element of said three-wire receptacle, said third male ground element being restrained from retracting into said recessed portion or ejecting therefrom by said end portion of said first spring-like device protruding into said recessed portion and engaging said indentation of said third male ground element, said indentation located so that said engagement therewith orients said third male ground element in an extended position permitting said reception of said third male ground element with said complementary female ground element;

said body having a configuration defining a second aperture and recessed portion within said body extending generally in a direction parallel to the longitudinal axis of said third male ground element, said second aperture being on that portion of the face of said electrical fitting which is opposite an electrically conductive fastener holding the cover plate of said two-wire receptacle when said pair of male elements make connective reception with said complementary female conductor elements of said two-wire receptacle, a second spring-like device retained within said second recessed portion, an electrically conductive plunger-like element contained by said second recessed portion and being electrically connected to ground therein, one end of said plunger-like element having a head portion capable of protruding beyond said second aperture outside of said second recessed portion, the other end of said plunger-like element having a rear portion opposite said first spring-like device and capable of making contact with said first spring-like device, said plunger-like element being depressed within said second recessed portion to permit said rear portion of said plunger to make contact with said first spring-like device and exert pressure against it causing it to flex, the flexure of said first spring-like device removing said end portion of said first spring-like device from engagement with said indentation of said third male ground element and thereby permitting retraction of said third male ground element within said first recessed portion;

a second position of said third male ground element permitting connective reception of said electrical fitting with said two-wire receptacle, said third male ground element being retracted within said first recessed portion of said body preventing abutment against said two-wire receptacle and allowing connective reception of said male elements of said electrical fitting with said complementary conductor female elements of said two-wire receptacle, and said second spring-like device exerting pressure against said plunger-like element forcing said head portion against said electrically conductive fastener of said two-wire receptacle to provide a close physical and electrical ground contact between said two-wire receptacle and said electrical fitting during connective reception thereof.

15. The structure of claim 14 wherein said first spring-like device within said hollowed out section comprises a flat spring with means of keeping said end portion thereof within said opening defined within said layer of material defining said recessed portion to enable said end portion of said first spring-like device to engage said indentation of said third male ground element when said third male ground element is properly positioned so said indentation on its external surfaces is opposite said opening within said layer of material;

said head portion of said plunger-like element comprised of material having magnetic properties, said head portion magnetically attracting said fastener of said two-wire receptacle when said fastener is comprised of magnetically attractive material and thereby maintaining a close physical and electrical ground contact between said two-wire receptacle and said electrical fitting during connective reception thereof.

16. The structure of claim 14 wherein said body defines a depressed portion on the face portion thereof through which said head portion of said plunger-like device projects, said depressed portion therein retaining said head portion of said plunger-like element when said electrical fitting is selectively connected to a three-wire receptacle;

said head portion of said plunger-like device being readily accessible within said depressed portion, said plunger-like device selectively depressed within said second recessed portion by pressure applied to said accessible head portion, said rear portion of said depressed plunger-like device making contact with and causing flexure of said first spring-like device causing said end portion thereof to disengage from said third male ground element and thereby releasing said third male ground element for retraction thereof within said first recessed portion and permitting selective connection of said electrical fitting with said two-wire receptacle.

17. The structure of claim 16 wherein stopping means prevent said first spring-like device from being flexed beyond a predetermined amount, said limited flexure of said first spring-like device being great enough to permit disengagement of said end portion thereof with said third male ground element but insufficient to remove said end portion of said first spring-like device from being oriented in a position permitting future engagement with said third ground male element upon release of flexure of said first spring-like device.

18. The structure of claim 16 wherein stopping means prevent said plunger-like device from being depressed beyond a predetermined distance, said rear portion of said depressed plunger-like device making contact with and causing flexure of said first spring-like device, said flexure being limited by said predetermined depressed distance of said plunger like device, said limited flexure of said first spring-like device being great enough to permit disengagement of said end portion thereof with said third male ground element but insufficient to remove said end portion of said first spring-like device from being oriented in a position permitting future engagement with said third ground male element upon release of flexure of said first spring-like device.