Direct tension indicating washers

• US 5,769,581 A
• Filed: 02/21/1997
• Issued: 06/23/1998
• Est. Priority Date: 02/21/1997
• Status: Expired due to Term

• Current Assignee: Applied Bolting Technology Products, Inc.
• Original Assignee: Applied Bolting Technology Products, Inc.
• Inventors: Wallace, Ivan Wayne, Herr, John A.
• Primary Examiner(s): Wilson, Neill R.
• Application Number:
  US08/804,217
• Time in Patent Office: 487 Days
• Field of Search: 411/3-5, 411/9-11, 411/13, 411/14, 116/212, 116/DIG. 34
• US Class Current: 411/10
• CPC Class Codes: F16B 31/028 with a load-indicating washer or washer assembly
• CPC Class Codes: G01L 5/243 using washers
• CPC Class Codes: Y10S 116/34 Tension indicating

Abstract

A direct tension indicating and maintaining washer has a first surface having at least one protuberance formed thereon and a second surface having at least one indentation formed therein opposite the protuberance. The inner diameter of the direct tension indicating and maintaining washer has an inner diameter wall meeting the second surface at an inner diameter edge. The outer diameter has an outer diameter wall meeting the second surface at an outer diameter edge. The inner diameter edge and the outer diameter edge lie in different planes. This causes the flattened direct tension indicating and maintaining washer to exert force against a bolt and maintain bolt tension. An alternative direct tension indicating and maintaining washer includes indicating material positioned in the indentation and a channel formed in the second surface leading from the indentation to the outside diameter of the direct tension indicating washer.

Claims

1. A direct tension indicating and maintaining washer comprising:

a first surface having at least one protuberance formed thereon for indicating bolt tension;

a second surface having at least one indentation formed opposite said protuberance;

an opening having an inner diameter wall, said inner diameter wall meeting said second surface at an inner diameter edge;

an outer diameter wall meeting said second surface at an outer diameter edge;

wherein said inner diameter edge and said outer diameter edge lie in different planes, said first surface and said second surface being planar and defining a frusto-conical shape for maintaining tension on a bolt upon installation.

2. The direct tension indicating and maintaining washer of claim 1 wherein said direct tension indicating washer is conical.

3. The direct tension indicating washer of claim 1 further comprising an indicating material positioned within said indentation and a channel formed in said second surface leading from said indentation to said outer diameter edge.

4. A direct tension indicating washer comprising:

a first surface having at least one protuberance formed thereon for indicating bolt tension;

a second surface having at least one indentation formed opposite said protuberance;

an indicating material positioned in said indentation; and

a channel formed in said second surface leading from said indentation to an outer diameter of said direct tension indicating washer,

wherein said first surface and said second surface being planar and defining a frusto-conical shape for maintaining tension on a bolt upon installation.