TORQUE INDICATING THREADED MECHANICAL FASTENING SYSTEMS AND METHODS

• US 20150377275A1
• Filed: 06/26/2015
• Published: 12/31/2015
• Est. Priority Date: 06/27/2014
• Status: Active Grant

• Current Assignee: Hubbell, Inc.
• Original Assignee: Hubbell, Inc.
• Inventors: De France, Robert Victor, Dobrinski, Daniel David, Hall, Jefferson Robert
• Granted Patent: US 10,378,576 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F16B 2/10 using pivoting jaws
• CPC Class Codes: F16B 31/028 with a load-indicating washer or washer assembly
• CPC Class Codes: F16G 11/00 Means for fastening cables or ropes to one another or to other objects; Caps or sleeves for fixing on cables or ropes attaching ropes or cables to lift cars or cages B66B7/08, to winch drums or barrels B66D1/34; ground anchors E02D5/00; anchoring devices for prestressed members E04C5/00; rope clamps in earth drilling E21B19/12

Abstract

Threaded mechanical fastening systems and methods are provided that allow the simple deflection of a washer to indicate that a desired minimum torque has been reached or that a desired maximum torque has been exceeded. The method includes providing a threaded connection having a washer, installing the threaded connection so that the washer is supported as a simple beam over a gap, and using an amount of deflection of the washer as a result of torque applied by the threaded connection as an indicator. The torque indicating threaded mechanical fastening system includes a threaded connection and a washer supported as a simple beam over a gap so that the threaded connection, when tightened to a predetermined torque, deflects, in bending, the washer into the gap.

Claims

1. A method of using washer deflection as a torque indicator, comprising:

providing a threaded connection having a washer;

installing the threaded connection so that the washer is supported as a simple beam over a gap; and

using an amount of deflection of the washer as a result of torque applied by the threaded connection as an indicator the amount of torque applied.

2. The method of claim 1, wherein the indicator is an indication that a desired minimum torque has been reached.

3. The method of claim 1, wherein the indicator is an indication that a desired maximum torque has been exceeded.

4. A torque indicating threaded mechanical fastening system, comprising:

a threaded connection; and

a washer supported as a simple beam over a gap so that the threaded connection, when tightened to a predetermined torque, deflects, in bending, the washer into the gap.

5. The system of claim 4, wherein the predetermined torque is a minimum torque such that the bending is an indication that the minimum torque has been reached.

6. The system of claim 4, wherein the predetermined torque is a maximum torque such that the bending is an indication that the maximum torque has been exceeded.

7. A spring loaded pad clamp, comprising:

a deflection washer having an outer dimension;

a threaded connection including a bolt and a nut;

an upper pad having a gap having edges that support the outer dimension of the deflection washer, the threaded connection having a portion that passes through the deflection washer and the gap, the threaded connection having a contact region that contacts the deflection washer, the gap being larger than the contact region so that the threaded connection, when tightened to a predetermined torque, deflects, in bending, the deflection washer into the gap.

8. The clamp of claim 7, wherein the predetermined torque is a minimum torque such that the bending is an indication that the minimum torque has been reached.

9. The clamp of claim 7, wherein the predetermined torque is a maximum torque such that the bending is an indication that the maximum torque has been exceeded.

10. The clamp of claim 7, wherein the predetermined torque is dependent upon at least one property of the deflection washer selected from the group consisting of a material, a thickness, an internal washer diameter, an outer washer diameter, and a heat treatment.

11. The clamp of claim 10, wherein the predetermined torque is dependent upon a width of the gap.

12. The clamp of claim 7, wherein the contact region comprises a region of contact between the deflection washer and either a head of the bolt or the nut.

13. The clamp of claim 7, wherein the contact region comprises a region of contact between the deflection washer and a second washer positioned between the deflection washer and either a head of the bolt or the nut.

14. The clamp of claim 7, wherein the gap has a width that is 60% larger than a diameter of a shaft of the bolt and the deflection washer has an outer diameter that is 60% larger than the width of gap.

15. The clamp of claim 7, wherein the edges of the gap further comprise a washer guide edge sufficient to center the deflection washer with respect to the gap.

16. The clamp of claim 7, wherein the edges of the gap further comprise a chamfer sufficient to center the deflection washer with respect to the gap.