About Us

Our focus is on producing the highest quality couplers on the market while meeting the delivery needs of our customers on their schedule.

At TJB we understand that the cost of downtime can quickly outstrip the cost of the parts needed to get back up and running. So to help our customers keep their down times to a minimum we limit our standard order lead times to 3 days for most orders and we can often ship emergency orders the same day.



In 1957 T.J. Brenner designed the first 7.5KV 500amp cable coupler. After a few years of seeing his design in real world use and not content watching the industry rest on its laurels, Ted founded TJB Inc. in 1970.  The design innovations in TJB’s early couplers quickly developed fans inside the mining industry once the reductions in downtime and reduced maintenance and installation times became apparent.  Once a steady business was up and running it was right back to the design table looking for a way to stay ahead of the competition that was by now copying the initial design improvements.  TJB went after what was then the biggest challenge in coupler operation, the coupling and un-coupling of 8 pitch threaded housings. In the late 70s a double start 4 pitch thread was designed and shortly after that a no-thread connection, both were received very well and customers that were once hesitant to buy from the new upstart started finding they couldn’t ignore TJB anymore.  The growing demand made the tight quarters of TJB’s first shop location in Rocky River, Ohio insufficient to meet the demands that were being placed on the company by its customers.
In 1980 production was moved to a new much larger location with room to grow in North Ridgeville, Ohio. With more space to work there was another boom in innovation at TJB with the development of an elastomer button installed in male copper contacts replacing the then standard multi-lam bands that often melted and fused to the contacts. By the early-90s it was time once again for TJB to shake up the industry; various types of rubber had been the standard insulating material since the inception of high voltage couplers.  The rubber was troublesome to keep clean and eventually would breakdown from the high electrical stresses it was exposed to, so TJB developed the industry’s first PTFE insulator.  No longer constrained by life of the rubber, physical abuse is now the main cause of a couplers eventual replacement. In 1998 after several requests from customers an entirely new line of couplers was designed to replace the unreliable square plugs sold by many of TJB’s competitors.  With the freedom of not having to connect to any existing couplers, the new design was able to incorporate all the best features of the traditional coupler along with a few new innovations. The new coupler line took off and sales have been steadily growing ever since.
After the success of the LVNT line there were again requests for an alternative to a competitor’s product and once again an entirely new product line was developed to fill an unmet need for TJB’s customers.  In 2008 the MLVNT line was launched, with focus on a compact housing and support for 1kv connections up to 500amps.  While that was the most recent significant advance there are small improvements happening all the time and always something big being tested for future release.