VIBRATION MEASURING ASSEMBLIES FOR ENERGIZED AND NON-ENERGIZED POWER LINE VIBRATION MEASUREMENTS

• US 3,771,356 A
• Filed: 03/14/1972
• Issued: 11/13/1973
• Est. Priority Date: 03/14/1972
• Status: Expired due to Term

• Current Assignee: David George Glass, Dennis William Johnson, Douglas Austin Bassett, Larry Allan Rodney Hoffman, Mitchell James, William Leslie Arnold Postle
• Original Assignee: David George Glass, Dennis William Johnson, Douglas Austin Bassett, Larry Allan Rodney Hoffman, Mitchell James, William Leslie Arnold Postle
• Inventors: Mitchell, James, Bassett, Douglas Austin, Glass, David George, Hoffman, Larry Allan Rodney, Postle, William Leslie Arnold, Johnson, Dennis William
• Primary Examiner(s): Queisser, Richard C.
• Assistant Examiner(s): Korkosz, Arthur E.
• Application Number:
  US05/234,599
• Time in Patent Office: 609 Days
• Field of Search: 33/148D,DIG.13 73/144,105,71.5,17A
• US Class Current: 73/658
• CPC Class Codes: H02G 7/14 Arrangements or devices for damping mechanical oscillations of lines, e.g. for reducing production of sound damping spacers H02G7/125
• CPC Class Codes: Y10S 73/01 Vibration

Abstract

A single point constant contact assembly is mounted on one end of a resilient cantilever beam either adjacent to or remote from an aerial conductor suspension clamp. The other end of the cantilever beam has bonded to it strain gauges to monitor deflections occurring in the conduits and these deflections are then amplified and transmitted to a remotely situated receiver station.

Claims

1. A live line vibration measuring assembly for use with energized and non-energized aerial cables and the like which are supported at spaced intervals by pylons which include pylon support members;

said assembly including a casing detachably secured to said cable, a strain gauge assembly in said casing, said strain gauge assembly including a strain gauge unit comprising a resilient cantilever beam secured by one end thereof within said casing and extending therefrom, strain gauges bonded upon each side of said beam adjacent said one end, a cable contact member on the other end of said beam in single constant contact with the surface of said cable and lying parallel to the run of said cable whereby the force generated by the contact of said member with said surface is parallel to the longitudinal axis of said beam thereby causing said beam to deflect, a transducer in said casing electrically connected to said strain gauges to receive signals generated by said strain gauges, remote signal receiving means and means operatively connecting said transducer to said remote signal receiving means.

2. The vibration measuring assembly according to claim 1 in which said means to support said casing includes a support bracket secured to the associated pylon support member, said casing being detachably clamped to said support bracket and means to preload said cantilever beam with reference to the associated cable.

3. The assembly according to claim 2 in which said last mentioned means includes means pivotally mounting said casing to said support member, a bracket extending from said casing and screw threaded bolt means engaging said bracket and said casing to vary the contact pressure of said cable contact member with said cable.

4. The assembly according to claim 2 in which said support bracket includes a horizontal portion pivotally secured adjacent one end thereof to said support member, an angulated portion formed on the other end of said support bracket, said strain gauge assembly being secured to said angulated portion, and spring loaded, screw threadable bolt means engaging said one end of said support bracket and reacting upon said support member to vary the contact pressure of said cable contact member with said cable, thereby preloading said cantilever beam with reference to the associated cable.

5. The vibration measuring assembly according to claim 1 in which said means operatively connecting said signals generated by said strain gauges to said signal receiving means includes a frequency modulated transmitter in said casing and a source of power for said transmitter, said transmitter including a sub-carrier oscillator, said sub-carrier oscillator including a current generator operated by said strain gauges, the current from said generator varying linearly with the strain experienced by said strain gauges, a compacitor in series with the output of said current generator and chargeable thereby with a predetermined reference potential, a source of voltage supply common to said strain gauges, said current generator and said reference potenial of said capacitor, a comparator in series between said capacitor and said source of voltage supply whereby one signal is provided for comparison purposes by said condenser and the other signal is provided for comparison purposes by said source of voltage supply, and electronic switch means operated by said comparator to discharge said capacitor when said signals are substantially equal, said oscillator output signal being connected to said transmitter.

6. The vibration measuring assembly according to claim 2 in which said means operatively connecting said signals generated by said strain gauges to said signal receiving meas includes a frequency modulated transmitter in said casing and a source of power for said transmitter, said transmitter including a sub-carrier oscillator, said sub-carrier oscillator including a current generator operated by said strain gauges, the current from said generator varying linearly with the sTrain experienced by said strain gauges, a compacitor in series with the output of said current generator and chargeable thereby with a predetermined reference potential, a source of voltage supply common to said strain gauges, said current generator and said reference potential of said capacitor, a comparator in series between said capacitor and said source of voltage supply whereby one signal is provided for comparison purposes by said condenser and the other signal is provided for comparison purposes by said source of voltage supply, and electronic switch means operated by said comparator to discharge said capacitor when said signals are substantially equal, said oscillator output signal being connected to said transmitter.

7. The vibration measuring assembly according to claim 3 in which said means operatively connecting said signals generated by said strain gauges to said signal receiving means includes a frequency modulated transmitter in said casing and a source of power for said transmitter, said transmitter including a sub-carrier oscillator, said sub-carrier oscillator including a current generator operated by said strain gauges, the current from said generator varying linearly with the strain experienced by said strain gauges, a compacitor in series with the output of said current generator and chargeable thereby with a predetermined reference potential, a source of voltage supply common to said strain gauges, said current generator and said reference potential of said capacitor, a comparator in series between said capacitor and said source of voltage supply whereby one signal is provided for comparison purposes by said condenser and the other signal is provided for comparison purposes by said source of voltage supply, and electronic switch means operated by said comparator to discharge said capacitor when said signals are substantially equal, said oscillator output signal being connected to said transmitter.

8. The vibration measuring assembly according to claim 4 in which said means operatively connecting said signals generated by said strain gauges to said signal receiving means includes a frequency modulated transmitter in said casing and a source of power for said transmitter, said transmitter including a sub-carrier oscillator, said sub-carrier oscillator including a current generator operated by said strain gauges, the current from said generator varying linearly with the strain experienced by said strain gauges, a capacitor in series with the output of said current generator and chargeable thereby with a predetermined reference potential, a source of voltage supply common to said strain gauges, said current generator and said reference potential of said capacitor, a comparator in series between said capacitor and said source of voltage supply whereby one signal is provided for comparison purposes by said source of voltage supply, and electronic switch means operated by said comparator to discharge said capacitor when said signals are substantially equal, said oscillator output signal being connected to said transmitter.