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."
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.
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.
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."
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.
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.
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
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.