Appeal No. 2001-1527
Application No. 08/753,265
Bullock
Bullock relates to a method of thermoforming hollow articles
in which a plug permits independent control of the wall cross-
section or thickness by selective stretching and distribution of
the material. (Bullock at col. 2, ll. 49–56.) Bullock
accomplishes these goals by providing a plug having a thermal
conductivity different from that of the remainder of the body of
the mold. (Id. at col. 3, ll. 25–28.) In embodiments, the plug
may be hollow, and may be provided with means to circulate
pressurized air as a way to increase the transfer of heat from
the plug. (Id. at col. 5, ll. 39–59, discussing Figure 4.)
Medwed
Medwed relates to a method of forming containers from a
thermoplastic sheet. (Medwed at col. 1, ll. 6–8.) According to
Medwed, the thermoplastic sheet is heated to its plastic (i.e.,
deformable) state, clamped at the periphery of the plastic
region, and then shaped by a molding die. (Id. at ll. 60–65.)
Referring to figures 2 through 6, the center of the molding die
is recessed so that the central portion 21 does not contact the
sheet material during the molding operation. (Id. at col. 3,
ll. 7–11.) Cooling air is directed against the sheet material
opposite the central portion 21 via ducts 23 through 26 that are
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