web address at US patent web site of the patent for a table which a
parturient (a woman in labor) lies on, which spins, to help the baby
come out using its centrifugal force.  I know it exists.

Inventors of a childbirth table that is rotated at high speed so that
centrifugal forces can aid in the birthing process.

http://www.improb.com/airchives/press/2003/LA-times-10-03-2003.html

Patented on Nov. 9, 1965, by George B. Blonsky (since deceased) and
Charlotte E. Blonsky of New York and San Jose, California, the
apparatus uses centrifugal force to facilitate childbirth. The mother
is strapped to a circular table, which is then rotated at high speed
(see figure). A piece of netting catches the baby so that he or she is
not flung against the wall.

http://www.cmaj.ca/cgi/content/full/161/12/1490

Diagrahm of device.

http://www.cmaj.ca/cgi/content/full/161/12/1490/F16

The patent number is 3,216,423. And according to the US patent office
the complete descritption does not exsist on there website.

No images.

Full text is not available for this patent. Click on "Images" button
above to view full patent

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=3216423.WKU.&OS=PN/3216423&RS=PN/3216423

This seems to be the originall patent. 

http://www.colitz.com/site/3216423/3216423.htm