Pantegrity

[Spencer W Hunter]

Last night, I completed my tendon-equator and anti-prism
self-deployable octahedral models, and will seek an opportunity to
have them photographed and put up on my web site.  I will announce
when they are ready.

While working on the anti-prism octa, I was struck by how terribly
similar it was to the basic unit of Emilio Pinero's deployable
pantographic dome.  In fact, if one thinks about it, the strut
configuration of Fuller's tensegrity octa and Pinero's pantograph are
identical, only the struts of Pinero's are connected by swivel bolts
at the center--as they must be, since there are no tendons in his
structure.

By combining the very powerful now-public-domain features of both
Fuller's and Pinero's developments, we are led to an entirely new
revolutionary hybrid structure that is neither purely a pantograph nor
a tensegrity: I am calling it a "pantegrity."  Like the pantograph,
the pantegrity does not rely on tendons for its structural integrity
and has a well-defined state during all stages of its deployment.
Once fully deployed, it behaves *exactly* like a tensegrity, with the
struts bearing only axial compression forces (and they have the
strength of half-struts, since they support each other at the center),
and the tendons bear only tensile forces.  One could think of the
tendons limiting the spread of the pantograph, and as such, they are
essential in determining the load-bearing strength of the structure.
Pinero himself was on to this when he recognized the benefit of the
canopy over his dome limiting the spread, but he saw this only as a
side feature and not an essential structural component.

Since the mechanism of the pantegrity is basically Pinero's, it almost
certainly works around Dr. Lalvani's bothersome current patent on
center-node construction.  That means the self-deployable pantegrity
dome may be manufactured and distributed by anyone, anywhere, and
at any time, without legal or financial obligation to anybody.

Its time is now.
---
Spencer Hunter, Tucson, AZ
gopher://www.u.arizona.edu:80/hGET%20/%7Eshunter