DYNAMOMETRICAL DEFLECTION MEASURING METHOD AND APPARATUS

• US 3,832,899 A
• Filed: 02/17/1972
• Issued: 09/03/1974
• Est. Priority Date: 02/17/1972
• Status: Expired due to Term

• Current Assignee: Ioan Victor Nicolau
• Original Assignee: Ioan Victor Nicolau
• Inventors: Nicolau, Ioan Victor
• Primary Examiner(s): Ruehl, Charles A.
• Application Number:
  US05/227,024
• Time in Patent Office: 929 Days
• Field of Search: 73/144,136R 318/6
• US Class Current: 73/862.194
• CPC Class Codes: G01L 5/08 using fluid means G01L5/042, G01L5/045 take precedence

Abstract

In order to measure by the deflection method the tension exerted in a belt or chain cable without producing errors of measurement due to variations in the deflection angle, the apparatus utilizes a deflection system comprising a compression dynamometer and two articulated bars. The dynamometer is axially positioned and joined with one of the bars. The two bars are each journalled at one end at a predetermined distance from two fixed deflection points, and at their other ends are joined together to a deflection roll. The two bars of the deflection system are thus constantly maintained parallel to the deflected cable or belt portions. Accordingly the angel between the two bars always remains equal to the deflection angle of the cable or the chain, regardless of the numerical value of the deflection angle. As a result, the compression force in each of the two bars, which is measured by the dynamometer, is always proportional to the tension force in each of the two deflected cable or chain portions, independently of variations in the deflection angle. The apparatus is particularly useful as a drillometer on the dead end of an operating cable, or as a torsiometer mounted on the chain of an intermediate transmission, or on the actuating transmission of the enclosed rotary table of drilling rigs in the oil and gas industry.

Claims

1. A method of dynamometrically measuring the tension force in a line subjected to static or moving tension comprising, in combination:

A. deflecting a portion of said line to produce two branches each forming a deflection angle Alpha with the axis of the adjacent, non-deflected line, B. providing a pair of articulated deflection bars each parallel and equal in length to one said branch and joined by a deflection member in contact with and biased by the deflected portion of said line, C. maintaining each deflection bar parallel to the corresponding branch regardless of variations in tension in said line, and D. measuring the axial force exerted in at least one said deflection bar as a result of the biasing force of said deflected portion as it varies under tension.

2. An apparatus for measuring the actual tension force exerted in a line subjected to static or moving tension comprising, in combination:

A. means for deflecting a portion of the line to produce two branches each forming a deflection angle Alpha with the axis of the adjacent, non-deflected line, B. a pair of deflection arms journalled together at one end with a deflection roll and each pivoted at opposite ends thereof spaced coextensively with the deflected portion of the line,

3. the other said arm being maintained parallel to the other branch of said deflected portion and carrying an axially mounted dynamometer, whereby the angle between the two deflection bars is maintained equal to the deflection angle Alpha regardless of the tension exerted in the line, and C. means for monitoring signals from said dynamometer.