Appeal No. 2003-1570
Application 08/748,986
equipment on a theatrical stage. Each batten 12 includes a
plurality of winch assemblies 14 which are electrically
interlocked by a control unit 16. The winch assemblies, which
act on cables 36, comprise drive units 32 having synchronous
motors 56 and overload/underload protection mechanisms 44 (see
Figures 6 and 7) having overload and underload limit switches 158
and 160 which shut down all winch assemblies on the batten if
tripped.
The examiner understands from Bayer’s disclosure that “an
overload or an underload condition would be one of the indicators
of the ‘relative’ difference between loading or travel of the
ropes” (answer, pages 5 and 6). Based on this understanding, the
examiner concludes that it would have been obvious in view of
Bayer’s overload/underload protection mechanism “to modify the
liftcrane of Durand by using sensors and an electronic processor
to control the hoist drums, to accurately synchronize the drums”
(answer, page 4).
Bayer’s description of the overload/underload protection
mechanism 44 (see column 11, line 33 et seq.), however, clearly
belies the examiner’s determination that an overload or underload
condition is indicative of a relative difference between the
travel of ropes or cables 36. In fact, the mechanisms 44 have
9
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Next
Last modified: November 3, 2007