| Copyright ZipNut Technology, LLC, 2008 |
News
SPACE TOOLS
Nuts for the Stars: Specialized Tools and Fasteners for
Construction In Space
By Tom Sawyer 8/11/2006
When the astronauts operating the robot arms of the space shuttle lift the big
modules into place to be fastened to the space station, motor-driven bolts will
spin into captive nuts to make the structural connection. To ensure fit, only one
nut in a pattern is fixed. The others have conical entries and can shift slightly
along differing vectors to ensure alignment.
But even though those connections have been largely automated, there is a
great deal of hand work to be done. The big, bulky space suits, which become
nearly rigid when pressurized, make hand and arm movements very tiring, so
work plans and tools are designed to minimize motion.
One of the standard devices is the 3/8 in.-drive, Handheld Rotary Device, a
13-lb, cordless, programmable, power wrench made by Swales Aerospace,
Beltsville, Md. The HRD's onboard computer accepts 14 settings for preset
speed, as well as number of rotations and torque, stopping at whichever of the
last two comes first, providing a potential warning for bad connections. If the
torque setting is reached before the specified rotations, for instance, it could
be a sign that something is in a bind and a joint might not be properly closed
and the digital display warns that something may be wrong.
Settings can be changed, even with an astronaut's bulky gloves, by rotating
rings on the barrel. The HRD is made of aluminum, titanium and stainless
steel. The 39 volt battery is good for 80 fasteners at the maximum torque of
25.0 ft-lb and can be exchanged on a spacewalk.
The astronauts also have a Swales right-angle programmable ratchet tool,
which has an umbilical cord to its belt-mounted controller. The long-handled
device can be used as a power tool for torque settings of up to 25.0 ft-lb, or as
a manual torque wrench for settings of up to 75 ft-lb. A wide range of
extensions and sockets, all drilled or ringed to accept tethers, are also
provided.
Swales also makes a range of high torque pliers and electrical connectors.
The tool line also includes a variety of retractable tethers-little boxes that can
be fastened to structures or the tool belt to keep items like nuts and sockets
from dropping overboard. The entire line can be seen at www.swales.com
Another elegant little connector NASA uses where motorized bolts won't work
is the "ZipNut®," a custom-made nut whose vertically split threads fit loosely in
a well within the nut, wrapped by a ring of stainless steel coiled spring. The
spring presses the thread collar inward. The nut can be "run down" the bolt
simply by pressing it down it. The spring loaded threads just open up and let it
pass, but close back on it when it hits home so its threads nest snugly with the
bolt threads. "With these things snapping into the threads, they engage the full
surface of the male unit, rather than just pulling on part of it, to get a perfect
match," says George Knapp, one of the two partners of ZipNut Technology,
LLC, Falls Church, Va.
The nut is tightened by giving it a turn or so, and then another design feature
goes to work: the funnel-shaped face of the base of the thread well means that
when force is applied to pull the nut up the bolt shaft, the pressure of the cone
against the thread jaws compresses them tighter against the bolt. The harder
you pull, the tighter it gets. And because of the conical seat, they tend to grip
harder when pulled against and even get tighter, rather than looser, with
vibration.
The company calls the simple configuration just described a "one-way
ZipNut®", because although it can be put it on by pressing it down the bolt, it
has to be unscrewed the old fashioned way. A more sophisticated version,
which NASA used extensively during repairs of the Hubble Telescope when
astronauts had to install some items, and then remove them again as part of
the process, is a "two-way ZipNut®." It has a knob built into the top that lets
you give the hub of the nut a counter turn to spring the threads open, which lets
it be lifted of as easily as it is put on.
"They all come in on a special order. The outer housing could be hex or
round... all sorts of things," says Hank Hulme, managing partner. "The capacity
is whatever the strength of the material is you want to make it out of. The
threads do not strip."
A number of fire departments are using the two-way ZipNut® in hose fittings
for making quick connections and disconnections. They are also being used
for some gas line applications. But in general, with the exception of some
specialty applications, ZipNuts® are not getting wide application-yet.
The hold-up to wider use, say Hulme and Knapp, is a legal one. They say they
invested in the company 10 years ago, shortly before the inventor ran into
serious legal problems in Nevada and the courts seized the assets of his
company. Hulme and Knapp were able to buy the patent from the court for
$100,000 a year and a half ago, but because the plaintiff has appealed the
case repeatedly through the subsequent years, they say they have not been
able to attract the kind of investment they would need to go into mass
production.
"That's one reason the company has not been able to go gangbusters," says
Hulme. "Every time venture capital comes around there is always something
better to invest in than a lawsuit."
As it is now, prices start at $15 for a simple ½ x 20 standard thread one-way
ZipNut®. "A relatively simple double zip may be $100, and one with an
elaborate outer body, specialized materials, could be $1,000," says Hulme.
The good news for Hulme and Knapp, however, is that the case has nearly
exhausted its appeal options, and they are hopeful that they will have clear
sailing for their product soon.
"We're on the precipice, ready to jump, or fly," says Hulme. Information on
ZipNuts® can be found at www.zipnut.com
SPACE TOOLS
Nuts for the Stars: Specialized Tools and Fasteners for
Construction In Space
By Tom Sawyer 8/11/2006
When the astronauts operating the robot arms of the space shuttle lift the big
modules into place to be fastened to the space station, motor-driven bolts will
spin into captive nuts to make the structural connection. To ensure fit, only one
nut in a pattern is fixed. The others have conical entries and can shift slightly
along differing vectors to ensure alignment.
But even though those connections have been largely automated, there is a
great deal of hand work to be done. The big, bulky space suits, which become
nearly rigid when pressurized, make hand and arm movements very tiring, so
work plans and tools are designed to minimize motion.
One of the standard devices is the 3/8 in.-drive, Handheld Rotary Device, a
13-lb, cordless, programmable, power wrench made by Swales Aerospace,
Beltsville, Md. The HRD's onboard computer accepts 14 settings for preset
speed, as well as number of rotations and torque, stopping at whichever of the
last two comes first, providing a potential warning for bad connections. If the
torque setting is reached before the specified rotations, for instance, it could
be a sign that something is in a bind and a joint might not be properly closed
and the digital display warns that something may be wrong.
Settings can be changed, even with an astronaut's bulky gloves, by rotating
rings on the barrel. The HRD is made of aluminum, titanium and stainless
steel. The 39 volt battery is good for 80 fasteners at the maximum torque of
25.0 ft-lb and can be exchanged on a spacewalk.
The astronauts also have a Swales right-angle programmable ratchet tool,
which has an umbilical cord to its belt-mounted controller. The long-handled
device can be used as a power tool for torque settings of up to 25.0 ft-lb, or as
a manual torque wrench for settings of up to 75 ft-lb. A wide range of
extensions and sockets, all drilled or ringed to accept tethers, are also
provided.
Swales also makes a range of high torque pliers and electrical connectors.
The tool line also includes a variety of retractable tethers-little boxes that can
be fastened to structures or the tool belt to keep items like nuts and sockets
from dropping overboard. The entire line can be seen at www.swales.com
Another elegant little connector NASA uses where motorized bolts won't work
is the "ZipNut®," a custom-made nut whose vertically split threads fit loosely in
a well within the nut, wrapped by a ring of stainless steel coiled spring. The
spring presses the thread collar inward. The nut can be "run down" the bolt
simply by pressing it down it. The spring loaded threads just open up and let it
pass, but close back on it when it hits home so its threads nest snugly with the
bolt threads. "With these things snapping into the threads, they engage the full
surface of the male unit, rather than just pulling on part of it, to get a perfect
match," says George Knapp, one of the two partners of ZipNut Technology,
LLC, Falls Church, Va.
The nut is tightened by giving it a turn or so, and then another design feature
goes to work: the funnel-shaped face of the base of the thread well means that
when force is applied to pull the nut up the bolt shaft, the pressure of the cone
against the thread jaws compresses them tighter against the bolt. The harder
you pull, the tighter it gets. And because of the conical seat, they tend to grip
harder when pulled against and even get tighter, rather than looser, with
vibration.
The company calls the simple configuration just described a "one-way
ZipNut®", because although it can be put it on by pressing it down the bolt, it
has to be unscrewed the old fashioned way. A more sophisticated version,
which NASA used extensively during repairs of the Hubble Telescope when
astronauts had to install some items, and then remove them again as part of
the process, is a "two-way ZipNut®." It has a knob built into the top that lets
you give the hub of the nut a counter turn to spring the threads open, which lets
it be lifted of as easily as it is put on.
"They all come in on a special order. The outer housing could be hex or
round... all sorts of things," says Hank Hulme, managing partner. "The capacity
is whatever the strength of the material is you want to make it out of. The
threads do not strip."
A number of fire departments are using the two-way ZipNut® in hose fittings
for making quick connections and disconnections. They are also being used
for some gas line applications. But in general, with the exception of some
specialty applications, ZipNuts® are not getting wide application-yet.
The hold-up to wider use, say Hulme and Knapp, is a legal one. They say they
invested in the company 10 years ago, shortly before the inventor ran into
serious legal problems in Nevada and the courts seized the assets of his
company. Hulme and Knapp were able to buy the patent from the court for
$100,000 a year and a half ago, but because the plaintiff has appealed the
case repeatedly through the subsequent years, they say they have not been
able to attract the kind of investment they would need to go into mass
production.
"That's one reason the company has not been able to go gangbusters," says
Hulme. "Every time venture capital comes around there is always something
better to invest in than a lawsuit."
As it is now, prices start at $15 for a simple ½ x 20 standard thread one-way
ZipNut®. "A relatively simple double zip may be $100, and one with an
elaborate outer body, specialized materials, could be $1,000," says Hulme.
The good news for Hulme and Knapp, however, is that the case has nearly
exhausted its appeal options, and they are hopeful that they will have clear
sailing for their product soon.
"We're on the precipice, ready to jump, or fly," says Hulme. Information on
ZipNuts® can be found at www.zipnut.com
ZipNut Technology, LLC
Phone: (703) 442-7339
Toll free: (888) 894-7688
E-mail info@zipnut.com
Phone: (703) 442-7339
Toll free: (888) 894-7688
E-mail info@zipnut.com
ZipNut Technology, LLC
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