Corner structure for door frames and the like

• US 3,899,258 A
• Filed: 03/26/1973
• Issued: 08/12/1975
• Est. Priority Date: 03/26/1973
• Status: Expired due to Term

• Current Assignee: David G. Matthews
• Original Assignee: David G. Matthews
• Inventors: Matthews, David G.
• Primary Examiner(s): Schroeder, Werner H.
• Application Number:
  US05/345,007
• Time in Patent Office: 869 Days
• Field of Search: 403/292,294,295,401,409 52/753C,753D,753G,758H
• US Class Current: 403/292
• CPC Class Codes: E06B 1/32 Frames composed of parts made of different materials
• CPC Class Codes: E06B 3/9682 Mitre joints
• CPC Class Codes: F16B 2200/65 Miter joints
• CPC Class Codes: Y10T 403/55 Member ends joined by inserted section
• CPC Class Codes: Y10T 403/555 Angle section
• CPC Class Codes: Y10T 403/76 having a cam, wedge, or tapered portion

Abstract

A frame member of the type having four frame members interconnected at each of four corners. Each of the frame members includes a channel. A plurality of right angled corner keys are inserted into the channels at each of the corners to assist in securing the frame members together. The corner keys have a substantially flat shape with a thickness substantially equal to that of the internal height of said channel. At least two laterally projecting unitary barb portions are provided on the sides of each of the legs. The outermost of the barb portions has a lateral dimension at least slightly greater than the internal width of the channel. The outermost barb portions thereby bite into the material defining said channel. The inner pair of the barb portions has a progressively increasing lateral dimension so that each of the subsequent barb portions bites into the channel as each of said legs is inserted further into said channel. Upon full assembly, the outermost of the barb portions has bit into the material defining the channel, and the innermost of the barb portions is also biting into the material defining the channel even though the outermost barb portion has previously bit into the material defining the channel.

Claims

1. A frame comprising a plurality of metallic elongated frame members, said frame members having mitered ends and having channel means defined therein, said channel means having a first pair of channel defining walls spaced a first distance apart, and a second pair of channel defining walls spaced a second distance apart, said mitered ends being in abutting relationship, a corner key for securing two elongated frame members together at said abutting ends to define corners, said corner key being of unitary, completely solid construction and being devoid of apertures therein, each corner key having a pair of legs at right angles to each other, each leg being rectangular in cross section and having a pair of opposite sides and a pair of opposite edges, said sides being spaced apart a distance which is substantially equal to said first distance and being received in said channel means in close sliding proximity to said first pair of channel defining walls, and a plurality of unitary sets of barbs on each of said edges of said legs, each of said barb sets including an outermost barb set with the spaced apart dimension of said outermost set being at least slightly greater than said second distance so as to provide for positive biting interengagement of said outermost set with the metal defining said second walls of said channel means, and also including an innermost set of barbs with the spaced apart dimension of Said innermost barb set being greater than said spaced apart distance of said first barb set to assure positive biting interengagement of said innermost barb set with the metal defining said second spaced walls, the biting interengagement of said barbs with the metal of said walls defining the sole means for securing said frame members together.