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Super Tools Become More Common in Manufacturing Operations
Alan Earls, Contributing Editor -- Design News, September 22, 2008
For instance, a patent recently granted to David Jensen, David Pett, and Paul Buehler provides for an automated method of installing traditional bolt, nut and washer combinations in demanding aerospace applications. In particular, according to US Patent and Trademark Office filings, the design aims to automatically avoid three primary fastener challenges, namely:
" (1) no "threads in bearing"--meaning that only the unthreaded shank section of a bolt is allowed to contact the structure being clamped up; (2) no "shanking"--meaning that the nut cannot run so far down the threads such that the nut enters the thread transition zone of the bolt, where the bolt threads may be incomplete in the vicinity of the shank section of the bolt; and (3) sufficient "thread protrusion"--meaning that a predetermined amount of thread length must protrude completely through the nut to ensure complete nut engagement."
In this invention, all these things are accomplished through a sophisticated melding of transducers and sensors, greatly simplifying a challenging task and ensuring accurate and consistent results.
Of course, the trend toward more and better tools (and fasteners) is hardly new. In the construction industry, for instance, almost every task has been abetted by power tools, often married to purpose-made fasteners, such as nails designed to work in nail guns. On the shop floor, Torx-, Robertson-, and hex-headed (Allen) fasteners, particularly when married to power, have significantly increased productivity when compared to traditional slotted or Phillips head fasteners.
Joe Barkai, practice director, product lifecycle strategies at Manufacturing Insights, says more advanced tools offer the hope of further improving productivity in many manufacturing disciplines, "whether the tools are used robotically or by humans."
In addition, Barkai says sophisticated tools that can measure and record torque values and other aspects of a manufacturing process, are a valuable tool for learning about failures. "Products can take many years to fail in the field but those failures are often related to fatigue issues - by matching specific failures to information from the assembly process, you can develop root cause analyses that are very powerful," he says.
When considering fastening options, there are a number of factors to weigh. For instance, automated fastening usually provides a higher level of confidence regarding correct torque and fastening tightness. In short, automated fastening reduces the human factor and reduces the possibility of cross-threading, under-torquing, breakage, even tool damage.
Increased automation also usually increases the speed of the assembly operation. This isn't only a matter of reducing the time spent per fastener but also making that time more consistent, which can reduce unpredictability and bottleneck effects.
Looking at automation also can be an opportunity to consider fastener options. The simplest choice is to use standard nuts, bolts, or rivets. However, vendors can often provide proprietary designs, or even develop specific designs for your needs, which can improve performance, reduce part count, and further enhance manufacturability.
