How New Vista Thread-Reconditioning Units Work
New Vista is the world’s foremost manufacturer of thread-reconditioning (thread remediation) 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.
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.
How New Vista Thread-Verification Units Work
New Vista is today the world’s largest manufacturer of thread-verification products for production applications. New Vista Thread-Verification Units (TVUs) are extensively employed in automotive parts plants, at production facilities for aircraft componentry and for industrial and construction equipment, and for constituent parts of medical devices. New Vista’s thread-verification products (and compliance devices) are used world-wide and they are covered by a number of patents.
The New Vista system is a “contact” system, meaning that an actual Thread Gage Member (TGM) is screwed into (or onto), and then back out of, the thread being verified. The system works equally well with internal or external threads. Prior to 2006, it was widely regarded that such a system would not be sufficiently fast nor sufficiently reliable for use in a production environment. At that time, noncontact systems were the preferred technology, in spite of the fact that those systems could not provide a positive verification. The introduction of New Vista’s ultra-reliable high-speed torque-responsive devices changed peoples’ perceptions, to the extent that today a large percentage of New Vista’s orders are to replace the older noncontact installations.
There are now more than 35 different models of New Vista Thread-Verification Units available. Having evolved from the original patent, they work basically like this: each features a motorized power unit that, through a low-inertia torque-limiting mechanism, runs a TGM into, through, or onto a threaded feature; and then reverses back out, thus providing 100% assurance that the thread is correct. New Vista TVUs will work with both internal and external threaded features. With the proper TVU, “GO”, “NO GO”, Combination, and Pipe Thread Gaging are all attainable.
A quick-response motor provides the power. Electric and air powered versions are both available. The low-inertia torque limiter permits the TGM to stall harmlessly when encountering wrong-size, wrong-pitch, short, incomplete, or damaged threads. Also in the drive is a compression-compensating mechanism, which allows the spindle to stop advancing in case the thread is missing, or if a threaded hole has a broken tap in it. If there is no thread present at all, the TGM simply spins ineffectually at the mouth of the hole. These features prevent damage to the TVU, the TGM and the piece part. Any of these events will cause built-in sensors to signal a reject.
To back the TGM out of the hole (or off an external thread), the TVU’s drive, when reversed, bypasses the torque control device and reverses out at full motor torque. This feature ensures that the TGM will always exit the part, even if it has just jammed in a tapered, short or damaged thread.
A standard New Vista TVU will permit a moderate amount of compliance for out-of-position or angularly-mislocated threads. 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 TGM to freely enter threads even though they are significantly mis-positioned.
How New Vista Compliant And Supercompliant Toolholders Work
For Thread Verification and Thread Reconditioning Applications
Whether the application is thread verification of existing threads, or reconditioning deformed or impeded existing threads, it is essential that the correct toolholder be selected. In all cases the tool must follow the existing thread with as little impediment or resistance as possible. Ordinary floating tapholders, or rubber couplings are not suitable for these kinds of work; their use will result in stalling at entry, metal adhesions or out-of-phase rethreading. A properly designed compliant toolholder, will, in contrast, allow the tool to make effortless entry 100% of the time, and then permit the tool to glide easily through any correctly-sized thread.
As an example of a Compliant Toolholder in a real life application: VFLX16 (found in the Video Gallery) is a video of a 4-Spindle Unit inspection station. Its purpose is to thread-verify four M8 inserts in molded automotive pedal modules. It was originally built without New Visa componentry, but it was retrofitted in early 2017 with New Vista FLX Spindles and DDG Supercompliant Toolholders. The application was challenging because the pedal modules might be hot, coming right off of the molding press; or they might instead be cold, if recently removed from a cold warehouse. So the threaded holes are often not in predictable locations. The original builder of the inspection station tried rubber coupling devices to gain compliance, but entry problems emerged, resulting in too many false rejects. Retrofitting the station with New Vista DDGX2 Compliant Toolholders completely solved the problem: the tools now enter correctly every time and they then glide right through the thread.
Compliant Toolholders are not just for thread verification. They will carry a lot of torque, so they are well suited to thread chasing or retapping applications, as well. Visit the AD-420 Compliant Toolholder and DDG Supercompliant Toolholder page or contact your New Vista Applications Engineer to find out which Toolholder is best suited to your application.