Patent ID: 6841104

Claim:
A method of injection molding a plastic product having a base wall and a sidewall, the method comprising the steps of: (a) shaping a mold cavity by combining a first mold part and a second mold part in opposition to one another; (b) injecting fluid plastic material into a base-wall section of a mold cavity; and (c) conducting said injected plastic material through at least one flow guide in the base-wall section and thence into a sidewall section of the mold cavity; wherein step (a) comprises the step of: (d) shaping a portion of a given said base-wall section flow guide by partially opposing a row of recesses in the first mold part with a row of recesses in the second mold part with the recesses in the first mold part being so staggered with respect to the recesses in the second mold part as to provide a chain of overlapping recesses that form a sequence of variable-opening throttles having openings that can vary within the given flow guide whenever the alignment between the combined first and second mold parts varies in response to variations in the thickness of a region of the sidewall section into which injected plastic material is conducted from the given flow guide so that upon an increase in the thickness of said region the openings of said throttles in the given flow guide decrease and so that upon a decrease in the thickness of said region the openings of said throttles in the given flow guide increase.