Safety locking system

• US 4,264,792 A
• Filed: 09/20/1979
• Issued: 04/28/1981
• Est. Priority Date: 09/20/1979
• Status: Expired due to Term

• Current Assignee: Brammall, Inc. (Tyden Group, Inc.)
• Original Assignee: Brammall, Inc. (Tyden Group, Inc.)
• Inventors: Gillette, Robert
• Primary Examiner(s): Little, Willis
• Application Number:
  US06/077,351
• Time in Patent Office: 586 Days
• Field of Search: 200/44, 200/276
• US Class Current: 200/43.08
• CPC Class Codes: H01H 27/06 Key inserted and then turned to effect operation of the switch
• CPC Class Codes: H01H 31/003 Earthing switches H01H31/02 - H01H31/26 take precedence; contact made by liquid jet H01H29/32; for substations H02B1/16, H02B5/01; for withdrawable switchgear H02B11/28; for gas-insulated switchgear H02B13/075

Abstract

A safety locking switch that can connect a selected wire to a grounded plate, on which the switch is mounted, has a metallic housing, a key operated lock mounted in the housing, an insulator affixed to the housing and an electrical lead extending through the insulator into the housing. In the locked position, the lock is in contact with both the electrical lead and the housing thereby grounding the selected wire connected to the lead. When unlocked by the key, the lock moves away from the end of the lead within the housing thereby open circuiting the path between the grounded plate and the selected wire.

Claims

1. A key operated safety lock mountable on a plate with a hole therein for providing a closed circuit between a selected wire and the plate comprising:

an elongated tapered conductive housing mountable on the plate with a centered axial boring therein and a restriction in said boring adjacent a rear surface of said housing;

a cylindrical, conducting, means for locking, having a key slot, mounted within said boring and movable axially a limited distance from a locked position to an unlocked position in response to a selected key inserted into said key slot;

an elongated rigid insulator with a shoulder at a first end thereof, a threaded body portion and an axial boring therethrough positioned with said shoulder in said tapered housing adjacent said restriction, with a portion of said insulator extending through said restriction and the remainder of said insulator extending axially away from said rear surface of said housing,

a nut threadable onto said insulator,

an electrical conductor formed as a substantially straight elongated conducting wire having an end shaped as a compression spring, said compression spring is positioned in said axial boring adjacent said shoulder of said insulator and said wire extends through said axial boring in said threaded body of said insulator,

whereby said tapered housing is securely connectable to the plate by extending said threaded body portion of said insulator through the hole in the plate and threading said nut onto said threaded body portion of said insulator behind the plate and only when said conducting means for locking is in the locked position does an end of said means for locking contact an end of said compression spring to provide a closed circuit between said wire and the plate.

2. In a key operated safety lock mountable on a plate with a hole therein for providing a closed circuit between a selected wire and the plate wherein the lock has an elongated conductive housing mountable on the plate with a centered axial boring therein and a key actuated cylindrical means for locking mounted within said boring movable axially a limited distance from a locked position to an unlocked position in response to a selected key being inserted into said key slot, an improvement comprising:

an exterior tapered surface on said housing and a restriction in said boring adjacent a rear surface of said housing,

an elongated rigid insulator with a shoulder at a first end thereof and an axial boring therethrough positioned with said shoulder in said boring in said tapered housing adjacent said restriction, with a portion of said insulator extending through said restriction, and with a section of said insulator extending axially away from said rear surface of said housing,

a fastening means connectable to said section of said insulator,

an electrical conductor formed as a substantially straight elongated conducting body having an end shaped as a compression spring,

said compression spring is positioned in said axial biring in said tapered housing adjacent said shoulder of said insulator with said elongated conducting body extending through said axial boring in said insulator,

whereby said tapered housing is securely connectable to the plate by passing said section of said insulator through the hole in the plate and attaching said fastening means onto said section of said insulator behind the plate,

when the means for locking is in the locked position, an end of the means for locking contacts an end of said compression spring providing a closed circuit between said elongated conducting body and the plate, and when the means for locking is moved axially away from the locked position to the unlocked position, said end of said means for locking moves away from said end of said compression spring thereby opening the circuit between said elongated conducting body and the plate.

3. The key operated safety lock according to claim 2, wherein:

said body portion of said elongated rigid insulator is threaded and said means for fastening comprises a nut threadable onto said insulator.

4. The key operated safety switch according to claim 2, wherein said means for locking is axially movable from an unlocked to a locked position without using a key.