If you have never visited the US patent database this is patent
might be a good introduction. Searches of the database for various
apiculture related patents can be entertaining. I expect few have made money
from most of the listed patents.
The scanned pages of the patent are available for most recent patents.
Visit:
http://patent.womplex.ibm.com/details?patent_number=5571247
to see
Patent 571247 :Self containing enclosure for protection from killer bees
Searches for
bee and hive
hive and tool
honey and frame
yeild various patents. The database goes back to 1971.
Happy surfing.