Auto-venting for polyurethane foam
First Claim
1. A device for molding a foam product comprising:
- a plurality of mold portions cooperable to form a foam mold assembly defining a mold cavity therein, having at least one vent hole in an upper portion thereof, said mold cavity being capable of having an expandable foamable material provided therein during a filling cycle which is reactively expanded within said mold cavity so as to be molded into a shape of said mold cavity during a foaming cycle, said expandable foamable material approaching said vent hole while expanding within said mold cavity during said foaming cycle, said at least one vent hole providing a passage through which air and reaction product gases introduced into said mold cavity as a byproduct of said reactive expanding of said expandable foamable material can escape to atmosphere from said mold cavity during said foaming cycle;
a sensing and signal generating assembly comprising a capacitive sensor in communication with said expandable foamable material and constructed and arranged for detection of a change in a dielectric characteristic within the mold cavity at a distance to said at least one vent hole as a result of said expandable foamable material approaching said at least one vent hole and to generate a signal in response to said detection; and
a sealing mechanism cooperable with said at least one vent hole constructed and arranged to close said passage when said sensing and signal generating assembly generates said signal in response to said detection of said expandable foamable material at said distance to said at least one vent hole to prevent said expandable foamable material approaching said at least one vent hole from escaping said mold cavity through said passage.
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Accused Products
Abstract
A device for molding foam products including upper and lower portions cooperable to form a foam mold defining a mold cavity therein. The upper mold portion has at least one vent hole therein. A mechanism for providing the mold cavity with an expandable foam during a filling cycle is also provided. The expandable foam reactively expands when provided within the cavity so as to be molded into the shape of the cavity during a foaming cycle. The foam approaches the vent hole while expanding within the mold cavity during the foaming cycle. At least one vent hole provides a passage through which air and reaction product gases introduced into the cavity as a byproduct of the reactive expanding of the foam can escape to atmosphere from the cavity during the foaming cycle. A sensing and signal generating assembly detects the presence of the foam at a predetermined proximity to the at least one vent hole during the foaming cycle and generates a signal in response to the detection. Finally, a sealing mechanism cooperates with the at least one vent hole to close the passage when the sensing and signal generating assembly generates the signal in response to the detection of the foam at the predetermined proximity to the at least one vent hole to prevent the foam approaching the vent hole from escaping the cavity through the passage.
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Citations
11 Claims
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1. A device for molding a foam product comprising:
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a plurality of mold portions cooperable to form a foam mold assembly defining a mold cavity therein, having at least one vent hole in an upper portion thereof, said mold cavity being capable of having an expandable foamable material provided therein during a filling cycle which is reactively expanded within said mold cavity so as to be molded into a shape of said mold cavity during a foaming cycle, said expandable foamable material approaching said vent hole while expanding within said mold cavity during said foaming cycle, said at least one vent hole providing a passage through which air and reaction product gases introduced into said mold cavity as a byproduct of said reactive expanding of said expandable foamable material can escape to atmosphere from said mold cavity during said foaming cycle; a sensing and signal generating assembly comprising a capacitive sensor in communication with said expandable foamable material and constructed and arranged for detection of a change in a dielectric characteristic within the mold cavity at a distance to said at least one vent hole as a result of said expandable foamable material approaching said at least one vent hole and to generate a signal in response to said detection; and a sealing mechanism cooperable with said at least one vent hole constructed and arranged to close said passage when said sensing and signal generating assembly generates said signal in response to said detection of said expandable foamable material at said distance to said at least one vent hole to prevent said expandable foamable material approaching said at least one vent hole from escaping said mold cavity through said passage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification