No title available

• US 3,771,098 A
• Filed:
• Issued:
• Est. Priority Date: 05/16/1972
• Status: Expired due to Term

• Current Assignee: N/A
• Original Assignee: N/A
• Time in Patent Office: Days
• US Class Current: 439/101
• CPC Class Codes: H01R 13/652 with earth pin, blade or socket

Abstract

A means for monitoring the integrity of a ground circuit in the connection of an electrical apparatus to an electric utility outlet through a power cord and plug. The means comprises a wall receptacle having two contacts, each of which is connected to the utility ground conductor, and a plug having a ground prong comprising two members which are adapted, respectively, for engaging the two ground contacts of the wall receptacle. One of the ground prong members is connected in a conventional manner through the power cord of the apparatus to the apparatus case. The second ground prong member is connected to the apparatus case through a continuity-sensing device whereby any failure of the ground conductor and the power cord or the connection of the ground prong to the ground contact and the wall receptacle will be immediately detected. In an alternative embodiment, the second power cord ground conductor is connected directly to the apparatus case and through the plug and wall receptacles to a remote continuity-sensing device to monitor the integrity of the ground circuit not only in the apparatus power cord and plug-to-wall receptacle connection, but also in the utility wiring of the structure in which the apparatus is located.

Claims

1. A receptacle for use in a ground conductor, said receptacle comprising:

a. a base member having first, second and third sockets therein arranged in conventional 120 volt grounded receptacle pattern with the first socket having a contact therein adapted to be connected to a hot conductor, the second socket having a contact therein adapted to be connected to a neutral conductor and the third socket having a contact therein adapted to be connected to a ground conductor; and

, b. a second contact in the third socket electrically insulated from the first contact therein, said second contact being adapted to be connected to a second conductor and being disposed so as to not interfere with the insertion of a conventional 120 volt grounded plug into the receptacle.

2. A plug for use in a ground conductor, said plug comprising:

a. a base member having first, second and third prongs extending therefrom and arranged in a conventional 120 volt grounded plug pattern with the first prong having a conductor portion adapted to be connected to a hot conductor, the second prong having a conductor portion adapted to be connected to a neutral conductor and the third prong having a conductor portion adapted to be connected to a ground conductor;

b. a second conductor portion on the third prong electrically insulated from the first conductor portion thereof, said second conductor portion being adapted to be connected to a second conductor and being disposed so as to not interfere with insertion of the plug into a conventional 120 volt grounded receptacle.

3. A power connector comprising:

a. a receptacle having first, second and third sockets therein, said sockets having contacts therein adapted to be connected to hot, neutral and ground conductors, respectively;

b. a plug adapted to be plugged into said receptacle and having first, second and third prongs extending therefrom for insertion into the respective first, second and third sockets of the receptacle upon plugging of the plug into the receptacle, each prong having a conductor portion adapted to engage the contact in the socket into which it is inserted; and

, c. a second contact in the third receptacle socket and a second conductor portion on the third prong adapted to engage the second contact of the third socket upon plugging of the plug into the receptacle.