Appeal No. 1998-0277
Application No. 08/478,009
Initially, this panel of the Board notes that we appreciate
from a reading of the background section of appellants'
specification (pages 1 through 3) that, prior to the present
invention, those having ordinary skill in the art used a planar
heating element (U.S. Patent No. 3,013,925) to melt endwalls of
pipe sections (page 2), and after heating, the end walls were
brought together and joined (butt-joint). Further, we are
instructed that those having ordinary skill in the art also
understood (U.S. Patent No. 5,185,049) that to butt-weld double
containment pipe sections (page 3) opposing endwalls of the pipes
should be brought into contact with a hinged planar heating
element until the plastic of the pipes is softened, with the
softened ends being subsequently joined together to form a solid
butt-joint.2 Appellants point out that the planar nature of this
heating element precludes use for assembling complex fittings
such as tee, wye, and cross or reducing fittings which require
detailed calculation of angled mating surfaces.
2 It is apparent to us from the background section that
those versed in this art, at the time of the present invention,
clearly understood that welding techniques using a common heater
for joining single pipe to single pipe was also applicable for
joining double containment pipe to double containment pipe. This
understanding is brought to the examiner's attention in the
"REMAND TO THE EXAMINER", infra.
4
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 Next
Last modified: November 3, 2007