New Vista is the world’s foremost manufacturer of thread-reconditioning (clean-out/chasing) products for production applications. New Vista Thread-Clearing Units (TCUs) are employed worldwide, in automotive parts plants, and at many other types of production facilities to chase weld spatter, coating, paint and other obstructions.
There are now more than 22 different models of New Vista Thread-Clearing Units available. The most popular models are featured here on New Vista’s Website.
Each TCU features a motorized power unit that, through a low-inertia torque-limiting mechanism, runs a Reconditioning Tool into, through, or onto a threaded feature; and then it reverses the Tool back out. New Vista TCUs will work with both internal and external threaded features.
A quick-response motor provides the power. A low-inertia torque limiter permits the Chasing Tool to remove most obstructions, but, if a massive obstruction is encountered, the Unit’s preset (and adjustable) torque limit will be exceeded, and the spindle will stall harmlessly. This is normally only an issue when encountering wrong-size, wrong-pitch, short, incomplete, or hopelessly damaged threads. The reason this torque-limiting feature is important is that, if excessive torque would be provided, the result could be inadvertent out-of-phase rethreading.
Also in the drive is a compression-compensating mechanism, which allows the spindle to stop advancing in case the thread is entirely missing, or if a threaded hole has a broken tap or other serious obstruction in it. Any of these events will cause built-in sensors to signal an incomplete cycle. These features prevent damage to the TCU, the Toolholder, the Reconditioning Tool and the production part.
To back the Reconditioning Tool out of the hole (or off an external thread), the TCU’s drive, when reversed, automatically bypasses the torque control device and reverses out at full motor torque. This capability ensures that the Reconditioning Tool will always exit the part, even if it has just jammed in a short thread.
Any standard New Vista TCU will allow a moderate amount of compliance for out-of-position or angularly-mislocated threads. But for applications where a large amount of positional error must be accommodated (such as welded nuts on car frames), New Vista supplies a variety of Compliant Toolholders that allow the Reconditioning Tool to freely enter and easily pass through threads even though they are significantly mis-positioned. Your New Vista applications engineer can help you select the best Toolholder to fit your requirement.