Appeal No. 2003-1570
Application 08/748,986
THE INVENTION
The invention relates to a method of operating a liftcrane.
Representative claim 17 reads as follows:
17. A method of operating a liftcrane that has a boom, first
and second hoisting mechanisms and a first rope and a second
rope, comprising the steps of:
a) winding a first end of said first rope on the first
hoisting mechanism;
b) winding a first end of said second rope on the second
hoisting mechanism;
c) coupling a second end of said first rope to a second end
of said second rope in a manner that transfers tension equally
between said ropes;
d) operating the liftcrane to lift a load suspended from the
boom and coupled to said first and second ropes by combined
action of the first hoisting mechanism and the second hoisting
mechanism wherein both the first and second hoisting mechanisms
each lift a substantially equal part of the load and the first
and second hoisting mechanisms together lift the entire load;
e) sensing the relative amount by which said first ends of
said ropes are being taken up and sending a signal indicative of
said sensing to a processor having a synchronization routine; and
f) adjusting operation of at least one of said hoisting
mechanisms based upon said routine operating on said signal from
said sensing.
THE PRIOR ART
The references relied on by the examiner to support the
final rejection are:
Durand 3,575,300 Apr. 20, 1971
Maltby et al. (Maltby) 3,847,251 Nov. 12, 1974
Bayer 5,361,565 Nov. 8, 1994
Guerrero, 2 187 160 A Sep. 3, 1987
British Patent Document
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