Purkeys announced it has partnered with Silver Eagle Manufacturing to give “additional capability and reliability” to Silver Eagle’s new adjustable trailer dolly. According to the company, the 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, according to the company.“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.”
