Purkeys and Silver Eagle Collaborate on the T-Dolly, an Adjustable Converter Dolly

Feb 22, 2016, 11:30 ET from Purkeys

LOWELL, Ark., Feb. 22, 2016 /PRNewswire/ -- Purkeys, a company focused on providing electrical solutions for the heavy-duty trucking industry, partnered with Silver Eagle Manufacturing to give additional capability and reliability to Silver Eagle's new adjustable trailer dolly. This revolutionary dolly allows the gap between trailers to be decreased at highway speeds to improve tracking and fuel economy.

Silver Eagle's new T-Dolly automatically telescopes and retracts to adjust the gap between trailers based on the information received by the control module Purkeys designed. "The people at Silver Eagle recognized that having an electronic controller would improve their T-Dolly," Purkeys' Chief Engineer Dale Henningson said. "Purkeys' expertise is in electronic controllers so we were a good fit for partnering up with them on this project." According to Henningson, the control module was designed to perform two main functions: control the distance between trailers and charge the battery.

Purkeys' control module relies on speed sensors to provide feedback on whether the dolly needs to be extended or retracted. Once the vehicle reaches 45 mph, an electro-hydraulic pump pulls the trailers closer together. When the speed slows to 40 mph and below, the T-Dolly increases the gap and allows the vehicle to make turns safely. To prevent gap adjustments at unnecessary times, the control module has certain parameters programmed that must be met before the T-Dolly will retract or expand. There is also a safety feature installed that will automatically return the trailers to the extended position if any one of several errors are detected. A service light will then flash to indicate the problem and allow for troubleshooting.

According to Gary Gaussoin, president of Silver Eagle Manufacturing, supplying power to the electro-hydraulic pump presented some issues for the T-Dolly design. "It's well known that power from the 7-way is not always constant and when you have combination trailers, you can get a big voltage drop," Gaussoin said. Purkeys worked with Silver Eagle Manufacturing to improve this issue. Knowing that the 7-way voltage is not always the most reliable power source, Purkeys utilized a DC/DC converter to boost the voltage from the 7-way and keep the hydraulic pump battery charged.

Adjusting the gap between trailers allows fleets to improve vehicle stability and fuel efficiency while allowing drivers to make turns safely at low speeds. The logic provided by the control module and the safety features ensure the adjustable T-Dolly works properly without jeopardizing the truck batteries.


For more than 20 years, Purkeys has delivered innovative, cost-effective solutions for the electrical needs of heavy-duty fleets. They look at the electrical system as a whole, then strategically work to achieve the maximum return on investment while reducing maintenance costs and equipment usage. Their level of expertise has garnered more than 10 U.S. patents and attracted the attention of fleets, OEMs and other industry leaders throughout North America. For more information please go to purkeys.net.


Silver Eagle, based in Portland, Oregon, is a leader in the development, design and integration of Truck-Trailer equipment. In business since 1936, Silver Eagle has nearly 80 years of innovative products for over-the-road trucking fleets and U.S. and international militaries. The company is ISO 9001:2008 certified. For additional information, go to www.silvereaglemfg.com.

Press Contact:
Brooke McNeely, Content Director, (479) 287-4006
823 S. Lincoln St.
Lowell, AR 72745

Video - https://youtu.be/ZIeTa9cIRmg


SOURCE Purkeys