Variance From Patent Immaterial.
"Defendants further contend that the curved or
arched
surfaces of the Wright aeroplanes in commercial use are
departures from the patent, which describes `substantially
flat surfaces,' and that such a construction would
be wholly impracticable. The drawing, Fig. 3, however,
attached to the specification, shows a curved line inward
of the aeroplane with straight lateral edges, and considering
such drawing with the terminology of the specification,
the slight arching of the surface is not thought
a material departure; at any rate, the patent in issue
does not belong to the class of patents which requires
narrowing to the details of construction."