Outlet box knockout

• US 7,575,122 B2
• Filed: 12/16/2004
• Issued: 08/18/2009
• Est. Priority Date: 10/07/2003
• Status: Active Grant

• Current Assignee: Thomas & Betts International LLC (ABB Limited)
• Original Assignee: Lamson & Sessions Company (ABB Limited)
• Inventors: Revlock, Dennis P. Sr., Turcovsky, Gregory D., Hull, Eric G.
• Primary Examiner(s): Stashick; Anthony D
• Assistant Examiner(s): ELOSHWAY, NIKI MARINA
• Application Number:
  US11/014,136
• Publication Number:
  US 20050092506A1
• Time in Patent Office: 1,706 Days
• Field of Search: 220/3.2, 220/254.1, 220/266, 220/277, 220/284, 220/661, 174/666
• US Class Current: 220/3.2
• CPC Class Codes: H02G 3/085 including knock-out or tear-out sections

Abstract

A knockout in a sidewall of a plastic electrical box has a slot for receiving a screwdriver tip to apply a knockout force to the knockout. The slot is located adjacent the box bottom wall to minimize deformation of the sidewall by a knockout force.

Claims

1. An electrical outlet box of plastic material, said box having a plurality of walls, at least one knockout arrangement in at least one of said walls, said knockout arrangement comprising inner, intermediate and outer generally circular grooves in said wall circumscribing inner, intermediate and outer knockouts, each knockout having a slot therein adjacent its circumscribing groove for receiving a tip of a flat bladed screwdriver to apply a force to a knockout and separate same from the one wall, said knockout arrangement being positioned and oriented with said slots adjacent to another of said box walls so that the other box wall stiffens the one box wall to minimize deformation thereof when a knockout force is applied to one of said knockouts at the location of one of said slots.

2. The box of claim 1 wherein said grooves are eccentric with respect to one another and overlap one another at a tangent location, said grooves varying in depth from a minimum depth at said tangent location to a maximum depth generally opposite from said tangent location, and said slots being located generally opposite from said tangent location.

3. The box of claim 1 wherein said grooves are eccentric with respect to one another and overlap one another at a tangent location, and said slots being located generally opposite from said tangent location.

4. The box of claim 1 wherein said other box wall is a box bottom wall.

5. An electrical box having an open end, a bottom wall opposite from said open end and a peripheral wall extending between said open end and said bottom wall, at least one knockout circumscribed by a groove in said peripheral wall, said knockout having an outer surface with a slot therein adjacent said groove for receiving a screwdriver tip to apply a knockout force to the knockout for separating same from the peripheral wall, said slot being located adjacent to said bottom wall to minimize deformation of said peripheral wall when a force is applied to the knockout at the slot location;

wherein said knockout is one of a plurality of eccentrically positioned inner and outer knockouts circumscribed by inner and outer grooves in said peripheral wall, said inner and outer grooves overlying one another at a tangent location, each of said inner and outer knockouts having a slot therein for receiving a screwdriver tip, said slots in each of said inner and outer knockouts being located generally opposite from said tangent location and adjacent to said bottom wall.

6. The box of claim 5 wherein said inner and outer grooves have a common first depth at said tangent location and a second depth generally opposite from said tangent location that is greater than said first depth.

7. The box of claim 6 wherein said second depth is the same for all of said grooves.

8. An electrical box having an open end, a bottom wall opposite from said open end and a peripheral wall extending between said open end and said bottom wall, at least one knockout circumscribed by a groove in said peripheral wall, said knockout having an outer surface with a slot therein adjacent said groove for receiving a screwdriver tip to apply a knockout force to the knockout for separating same from the peripheral wall, said slot being located adjacent to said bottom wall to minimize deformation of said peripheral wall when a force is applied to the knockout at the slot location;

wherein said knockout is one of a plurality of eccentrically positioned inner intermediate and outer knockouts circumscribed by inner intermediate and outer grooves in said peripheral wall, said inner intermediate and outer grooves overlying one another at a tangent location, each of said inner intermediate and outer knockouts having a slot therein for receiving a screwdriver tip, said slots in each of said inner intermediate and outer knockouts being located generally opposite from said tangent location and adjacent to said bottom wall.

9. The box of claim 8 wherein said inner, intermediate and outer grooves have a common first depth at said tangent location and a second depth generally opposite from said tangent location that is greater than said first depth.

10. The box of claim 9 wherein said second depth is the same for all of said grooves.

11. A molded plastic wall having at least one knockout therein circumscribed by a groove in said wall, a slot in said knockout adjacent said groove for receiving a tip of a flat bladed screwdriver to apply a force to said knockout and separate same from said wall, a stiffening structure molded integrally with said wall and extending thereacross adjacent to said groove and said slot for stiffening said wall to minimize deformation thereof when a knockout force is applied to said knockout at the location of said slot;

wherein said knockout is one of a plurality of eccentrically positioned inner intermediate and outer knockouts circumscribed by inner intermediate and outer grooves in said peripheral wall, said inner intermediate and outer grooves overlying one another at a tangent location, each of said inner intermediate and outer knockouts having a slot therein for receiving a screwdriver tip, said slots in each of said inner intermediate and outer knockouts being located generally opposite from said tangent location and adjacent to said stiffening structure.