Electrical conduit and conduit system

Abstract

An electrical conduit piece of the invention has two external threaded regions, one threaded region having a left hand threaded region and one having a right hand threaded region. This conduit piece is particularly well adapted to be used in conventional conduit systems by coupling to conventional conduit pieces through a coupling of the invention having two internal threaded regions, one threaded region having left hand threads and the other threaded region having right hand threads. A groove may be formed in the internal wall of the coupling, e.g., at or near its longitudinal center to provide an open region in which ends of conduit pieces inserted into the coupling can abut. Residing in the grooved region of the coupling is a locking rind which scores the threads of the conduit pieces at 90° preventing any tangential force from outside of the system from unscrewing one of the conduit pieces from the coupling. In a preferred embodiment, the conduit piece is embodied as a curved or elbow conduit.

What is claimed is:  
     
         1 . A conduit system, comprising: 
 a plurality of first conduit pieces, each first conduit piece having a first end with a first threaded region and a second end with a second threaded region, with the first and second threaded regions having substantially the same first thread direction;    at least one second conduit piece having a first end with a first threaded region and a second end with a second threaded region, with the first and second threaded regions of the second conduit piece each having substantially the same second thread direction, with the second thread direction being different than the first thread direction; and    at least one coupling, the coupling comprising a first threaded portion and a second threaded portion, with the first threaded portion having a different thread direction than the second threaded portion, with the first threaded portion of the coupling configured to reversibly engage the first threaded region on the first conduit piece and with the second threaded portion of the coupling configured to reversibly engage the second threaded region on the second conduit piece to reversibly couple the first conduit piece with the second conduit piece;    and    at least one locking, the ring comprising a coarse threaded portion, the threaded portion being oriented to the inside of the ring and the threads being aligned perpendicular to the long axis, with the ring being formed to less than 360° and formed from a material having spring like characteristics.    
     
     
         2 . The system of  claim 1 , further comprising another coupling, the other coupling having a first threaded portion and a second threaded portion, with the first threaded portion having a different thread direction than the second threaded portion, the second threaded portion of the other coupling configured to engage the first threaded region on the second conduit piece and the first threaded portion configured to reversibly engage an end of another first conduit piece to couple the first end of the second conduit piece with an end of the other conduit piece, the locking ring to score grooves in the threads of the first and second threaded portion at 90° to the direction of the threads.  
     
     
         3 . The system of  claim 1 , wherein the first thread direction comprises right hand threads.  
     
     
         4 . The system of  claim 1 , wherein the second threaded direction comprises left hand threads.  
     
     
         5 . The system of  claim 1 , wherein the first threaded portion of the coupling comprises right hand threads and the second threaded portion comprises left hand threads.  
     
     
         6 . The system of  claim 1 , wherein the locking ring comprises coarse threads oriented perpendicular to the threads of claims  3 , 4 , and  5 .  
     
     
         7 . The system of  claim 1 , wherein the coupling comprises an internal groove region positioned such that when the first and second conduit pieces are coupled by the coupling, the first end of the first conduit piece abuts the second end of the second conduit piece in the internal groove region.  
     
     
         8 . The system of  claim 1 , wherein the first and second threaded regions of the first and second conduit pieces comprise external threads.  
     
     
         9 . The system of  claim 1 , wherein the first and second threaded portions of the coupling comprise internal threads.  
     
     
         10 . The system of  claim 1 , wherein the threaded portion of the locking ring comprises of internal threads.  
     
     
         11 . A conduit system, comprising: a plurality of first conduit pieces having a first end and a second end, with first externally threaded regions located at each end, each first threaded region comprising right hand threads; 
 a plurality of second conduit pieces having a first end and a second end, with second, externally threaded regions located at each end, each second threaded region comprising left hand threads; and    a coupling located between adjacent first and second conduit pieces and configured to reversibly engage one end of a first conduit piece with one end of an adjacent second conduit piece, the coupling comprising a first, internally threaded, right hand thread portion configured to engage an end of a first conduit piece and a second, internally threaded, left hand thread portion configured to engage an end of a second conduit piece, the coupling having an internal groove region positioned such that when the coupled ends of the first and second conduit piece are threaded into the coupling, the inserted ends abut in the internal groove region,    a locking ring abiding in the internal grooved region of the coupling and as the inserted ends of the conduit pieces enter the grooved region, they are scored at 90° by the coarse threads of the locking ring.    
     
     
         12 . A method of forming a conduit system, comprising the steps of: providing a plurality of first conduit pieces, each first conduit piece having a first end with a first threaded region and a second end with a second threaded region, with the first and second threaded regions having the same first thread direction; providing at least one second conduit piece having a first end with a first threaded region and a second end with a second threaded region, with the first and second threaded regions of the second conduit piece being of the same second thread direction, with the second thread direction being different from the first thread direction; providing a coupling having a first threaded portion and a second threaded portion, with the thread direction of the first and second threaded portions being different from each other; engaging the first threaded portion of the coupling with a first threaded region on a first end of a first coupling piece; engaging the second threaded portion of the coupling with a second threaded region on a second end of the second coupling piece; and rotating the Coupling in a first direction to thread the first end of the first coupling piece and second end of the second coupling piece into the coupling until the threads are scored by the locking ring and the ends abut.  
     
     
         13 . The method of  claim 12 , wherein the coupling has an internal groove region and the method comprises rotating the coupling such that the ends of the first and second conduit pieces are scored by the locking ring and abut in the groove region.  
     
     
         14 . The method of  claim 13 , including rotating the coupling in a second direction to disengage the first conduit piece from the second conduit piece.  
     
     
         15 . The method of  claim 12 , including inserting a flexible member through the first and second conduit pieces and the coupling before coupling the conduit pieces together.  
     
     
         16 . The method of  claim 12 , including providing another coupling having a first threaded portion and a second threaded portion, with the thread directions of the first and second threaded portions of the other coupling being different; 
 engaging the second threaded portion of the other coupling with the first end of the second conduit piece;    engaging the first threaded portion of the other coupling with an end of another first conduit piece; and    rotating the other coupling in a first direction to couple the first end of the second conduit piece with the end of the other first conduit piece.    
     
     
         17 . A method of retrofitting a conduit system having a plurality of first conduit pieces with opposed ends and threaded regions of the same thread direction located on each end, the first conduit pieces being coupled by first couplings having opposed ends with threaded portions of the same thread direction as the threaded regions of the first conduit pieces, the method comprising the steps of: 
 removing at least one first conduit piece and at least one of the first couplings;    replacing the removed first conduit piece with a second conduit piece having a first end and a second end, the first end having a first threaded region of the same direction as the first conduit piece and the second end having a second threaded region of different thread direction than the first threaded region;    replacing the removed first coupling with a second coupling, the second coupling comprising a first threaded region having the same direction as the first threaded region of the second conduit piece and a second threaded portion of the same thread direction as the second threaded region of the second conduit piece;    engaging the second threaded portion of the coupling with the second end of the conduit piece;    engaging the first threaded portion with an end of an adjacent first conduit piece; and    rotating the second coupling to engage the second end of the second conduit piece with the adjacent end of a first conduit piece until    
     
     
         20 . The method of  claim 17 , wherein the second coupling comprises a groove region wherein resides a locking rind and the coupled ends of the conduit pieces abut in the groove region.