Tamper-proof electrical receptacle

• US 4,820,187 A
• Filed: 10/16/1987
• Issued: 04/11/1989
• Est. Priority Date: 10/16/1987
• Status: Expired due to Fees

• Current Assignee: Donald M. May
• Original Assignee: Donald M. May
• Inventors: May, Donald M.
• Primary Examiner(s): DESMOND, EUGENE
• Application Number:
  US07/108,946
• Time in Patent Office: 543 Days
• Field of Search: 439/97, 439/102, 439/133, 439/144, 439/147, 439/304, 439/309, 439/345, 439/346, 439/359, 439/373
• US Class Current: 439/359
• CPC Class Codes: H01R 13/6395 for wall or panel outlets
• CPC Class Codes: H02G 3/12 for flush mounting

Abstract

An electrical receptacle of the three contact type, one of which receives the standard, normally non-current-carrying, system ground pin of a corresponding cap.

A set screw is advanced into a threaded bore in the plastic body material of the receptacle to make contact with the aforementioned ground pin. The bore may be from the receptacle front or from behind the face plate, in either case preventing the casual or surreptitious removal of the cap and cord and the associated equipment.

Claims

1. In a system including a three-conductor electrical receptacle which includes a solid insulating body for supporting socket members corresponding to said three conductors for mating to a three-pin cord-end cap having pins in a corresponding format, a first of said pins and its corresponding socket member constituting a normally non-conducting safety ground connection, said system including a cover plate over said receptacle body, said cover plate having an aperture therethrough permitting access from mating said cord-end cap to said receptacle, the combination comprising:

a threaded bore through said receptacle body at an angle from a point of contact with said first pin within said corresponding socket member to an external point adjacent to the inside surface of said cover plate;

a set screw within said threaded bore said screw being controllable at said external point to bear against said first cord cap pin to secure said cord cap against removal;

and an opening in said cover plate aligned with said threaded bore at said external point for insertion of a tool to control said set screw.

2. Apparatus for inhibiting the removal of a three-conductor cap mated into a three-conductor receptacle, said receptacle including a first socket member for receiving a first cap prong from a normally non-current carrying safety ground, and said receptacle having a body of solid insulating material formed to hold said first socket member in position to mate with said cap prong comprising:

a threaded bore into said receptacle body at an angle from an externally accessible location to a point along the length of said first cap prong when mated into said first socket member;

a set screw inserted into said threaded bore to bear against said first cap prong in said mated position, said set screw being controllable from said externally accessible location;

a cover plate attached to said receptacle body, said cover plate having an opening exposing an interface surface of said receptacle whereby said cap seats against said interface surface when said first socket member and said first cap prong are mated;

and an opening in said cover plate aligned with said threaded bore externally accessible location for tool access to advance or withdraw said set screw.