Method and apparatus for installing heavy electrical conductor lines in conduits

Claim 1

A method of facilitating the determination of the required length of a relatively heavy pliable electrical conductor line and effecting installation thereof in a conduit of substantial length which comprises the steps of providing a wound reel of thin lightweight plastic tape having graduated measuring indicia thereon, attaching the leading end of the tape to a resilient and compressible carrier plug, inserting the compressible carrier plug into the entrance end of the conduit in sealing engagement with the inner surface of the conduit with the tape trailing from the conduit, subjecting the carrier plug to differential fluid pressure to pass the same in sealing sliding engagement through the conduit and out of the exit end thereof to position the attached tape within and throughout the length of the conduit, noting the difference between the measuring indicia on the leading End of the tape and the trailing portion of the tape extending from the entrance end of the conduit to determine the desired length of an electrical conductor line, cutting the trailing portion of the tape extending from the conduit to separate the tape from the remainder thereof on the reel so the reel can then be used with additional conduits, attaching to the tape extending through the conduit one end of a strong pull line of greater strength than the tape, withdrawing the tape from the conduit to position the pull line therein, attaching one end of a pre-cut length of electrical conductor line of about said determined length to one end of the pull line, and withdrawing the pull line from the conduit to position the pre-cut electrical conductor line therein.

Claim 2

A method of facilitating the determination of the required length of a relatively heavy pliable electrical conductor line and effecting installation thereof in a conduit of substantial length which comprises the steps of providing a wound reel of thin lightweight plastic tape having graduated measuring indicia thereon, attaching the leading end of the tape to a resilient and compressible carrier plug, inserting the compressible carrier plug into the entrance end of the conduit in sealing engagement with the inner surface of the conduit with the tape trailing from the conduit, subjecting the carrier plug to differential fluid pressure to pass the same in sealing sliding engagement through the conduit and out of the exit end thereof to position the attached tape within and throughout the length of the conduit, noting the difference between the measuring indicia on the leading End of the tape and the trailing portion of the tape extending from the entrance end of the conduit to determine the desired length of an electrical conductor line, cutting the trailing portion of the tape extending from the conduit to separate the tape from the remainder thereof on the reel so the reel can then be used with additional conduits, attaching to the tape extending through the conduit one end of a strong pull line of greater strength than the tape, withdrawing the tape from the conduit to position the pull line therein, attaching one end of a pre-cut length of electrical conductor line of about said determined length to one end of the pull line, and withdrawing the pull line from the conduit to position the pre-cut electrical conductor line therein.

Claim 3

A method of facilitating the determination of the required length of a relatively heavy pliable electrical conductor line and effecting installation thereof in a conduit of substantial length which comprises the steps of providing a wound reel of thin lightweight plastic tape having graduated measuring indicia thereon, attaching the leading end of the tape to a resilient and compressible carrier plug, inserting the compressible carrier plug into the entrance end of the conduit in sealing engagement with the inner surface of the conduit with the tape trailing from the conduit, subjecting the carrier plug to differential fluid pressure to pass the same in sealing sliding engagement through the conduit and out of the exit end thereof to position the attached tape within and throughout the length of the conduit, cutting the trailing portion of the tape extending from the conduit to separate the tape from the remainder thereof on the reel so the reel can then be used with additional conduits, noting the difference between the measuring indicia on the leading end of the tape and the trailing portion of the tape extending from the entrance end of the conduit to determine the desired length of an electrical conductor line, cutting an electrical conductor line of about said determined length from a supply thereof to provide a pre-cut length thereof, attaching to the tape extending through the conduit one end of a strong pull line of greater strength than the tape, withdrawing the tape from the conduit to position the pull line therein, attaching one end of the pre-cut length of electrical conductor line to one end of the pull line, and withdrawing the pull line from the conduit to position the pre-cut electrical conductor line therein.

Claim 4

A method of facilitating the determination of the required length of a relatively heavy pliable electrical conductor line and effecting installation thereof in a conduit of substantial length which comprises the steps of providing a wound reel of thin lightweight plastic tape having graduated measuring indicia thereon, attaching the leading end of the tape to a resilient and compressible carrier plug, inserting the compressible carrier plug into the entrance end of the conduit in sealing engagement with the inner surface of the conduit with the tape trailing from the conduit, subjecting the carrier plug to differential fluid pressure to pass the same in sealing sliding engagement through the conduit and out of the exit end thereof to position the attached tape within and throughout the length of the conduit, cutting the trailing portion of the tape extending from the conduit to separate the tape from the remainder thereof on the reel so the reel can then be used with additional conduits, noting the difference between the measuring indicia on the leading end of the tape and the trailing portion of the tape extending from the entrance end of the conduit to determine the desired length of an electrical conductor line, cutting an electrical conductor line of about said determined length from a supply thereof to provide a pre-cut length thereof, attaching to the tape extending through the conduit one end of a strong pull line of greater strength than the tape, withdrawing the tape from the conduit to position the pull line therein, attaching one end of the pre-cut length of electrical conductor line to one end of the pull line, and withdrawing the pull line from the conduit to position the pre-cut electrical conductor line therein.

Claim 7

A method of facilitating the determination of the required length of a relatively heavy pliable electrical conductor line for installation thereof in a conduit of substantial length which comprises the steps of providing a wound reel of thin lightweight plastic tape having graduated measuring indicia thereon adjacent the entrance end of a conduit, attaching the leading end of the tape to a resilient and compressible carrier plug, inserting the compressible carrier plug into the entrance end of the conduit in sealing engagement with The inner surface of the conduit with the tape trailing from the conduit, subjecting the carrier plug to differential fluid pressure to pass the same in sealing sliding engagement through the conduit and out of the exit end thereof to position the attached tape within and throughout the length of the conduit, cutting the trailing portion of the tape extending from the conduit to separate the tape from the remainder thereof on the reel so the reel and the remainder of the tape thereon can then be used with additional conduits, and noting the difference between the measuring indicia on the leading end of the tape and the trailing portion of the tape extending from the entrance end of the conduit to determine the desired length of an electrical conductor line.

Claim 8

A method of facilitating the determination of the required length of a relatively heavy pliable electrical conductor line for installation thereof in a conduit of substantial length which comprises the steps of providing a wound reel of thin lightweight plastic tape having graduated measuring indicia thereon adjacent the entrance end of a conduit, attaching the leading end of the tape to a resilient and compressible carrier plug, inserting the compressible carrier plug into the entrance end of the conduit in sealing engagement with The inner surface of the conduit with the tape trailing from the conduit, subjecting the carrier plug to differential fluid pressure to pass the same in sealing sliding engagement through the conduit and out of the exit end thereof to position the attached tape within and throughout the length of the conduit, cutting the trailing portion of the tape extending from the conduit to separate the tape from the remainder thereof on the reel so the reel and the remainder of the tape thereon can then be used with additional conduits, and noting the difference between the measuring indicia on the leading end of the tape and the trailing portion of the tape extending from the entrance end of the conduit to determine the desired length of an electrical conductor line.

Claim 11

A device adapted to be secured to a carrier plug and passed through an electrical conduit by fluid pressure to determine the length of an electrical conductor line to be subsequently installed in the conduit; said device comprising a lightweight elongate tape of plastic material, said tape being formed of polypropylene plastic material having a relatively low coefficient of friction and being of thin flat cross-sectional form, said tape having a thickness of about 0.010 inch and a width about 50 times greater than the thickness thereof, said tape also having graduated measuring indicia along its length on at least one of the flat faces thereof, and said tape being characterized by having sufficient flexibility to permit the tape to readily flex and pass by any bends in the conduit but having sufficient cross-sectional stiffness to retain its width dimension and to avoid bowing into conforming relation to the transverse curvature of the conduit and having sufficient longitudinal flexibility to prevent the tape from being pushed through a conduit without folding upon itself but sufficient longitudinal stiffness to cause the tape, when released from a flexed condition, to substantially return to its original unflexed condition.

Claim 12

A device adapted to be secured to a carrier plug and passed through an electrical conduit by fluid pressure to determine the length of an electrical conductor line to be subsequently installed in the conduit; said device comprising a lightweight elongate tape of plastic material, said tape being formed of polypropylene plastic material having a relatively low coefficient of friction and being of thin flat cross-sectional form, said tape having a thickness of about 0.010 inch and a width about 50 times greater than the thickness thereof, said tape also having graduated measuring indicia along its length on at least one of the flat faces thereof, and said tape being characterized by having sufficient flexibility to permit the tape to readily flex and pass by any bends in the conduit but having sufficient cross-sectional stiffness to retain its width dimension and to avoid bowing into conforming relation to the transverse curvature of the conduit and having sufficient longitudinal flexibility to prevent the tape from being pushed through a conduit without folding upon itself but sufficient longitudinal stiffness to cause the tape, when released from a flexed condition, to substantially return to its original unflexed condition.