Apparatus for molding plastic shapes in molding recesses formed in a moving endless belt

Claim 2

Apparatus for molding plastic articles comprising an endless belt, means for continuously driving said belt longitudinally through an endless path, said belt having formed in one surface thereof a plurality of alternating ribs and grooves extending lengthwise of said path of said belt, at least some of the surface portions of said ribs and grooves having molding recesses sunk therein, and means for supplying plastic material in moldable condition under pressure to said surface of said belt in which said ribs and grooves are formed including a nozzle having spaced parallel lips defining a narrow slitlike opening with the lengthwise dimension of said opening extending transversely of the path of travel of said belt whereby one of said lips constitutes an entrance lip and the other of said lips constitutes an exit lip as related to the travel of said belt through said endless path, means for positioning said entrance and exit lips in contact with the surface of said belt in which said ribs and grooves are formed, said entrance lip having a contour defined by alternating notches and projections formed in said entrance lip such as to engage with a snug sliding fit all surfaces of said ribs and grooves, and said exit lip having a contour defined by alternating notches and projections formed in said exit lip such as to engage with a snug sliding fit at least a portion of those surfaces of said ribs and grooves in which said molding recesses are sunk, whereby as successive portions of said belt travel beneath said exit lip said exit lip will scrape plastic material off of the surfaces which are engaged by said exit lip while leaving plastic material remaining in all of said molding recesses.

Claim 3

Apparatus in accordance with claim 1 in which at least some of the projections formed in said exit lip have a length insufficient to penetrate the full depth of the associated grooves of said belt whereby to define in the lower portions of said associated grooves a plurality of extruding spaces of predetermined vertical dimension through which said plastic material will be extruded from said nozzle in the form of a plurality of parallel continuous strips of thicknesses corresponding with said predetermined vertical dimension and lying in the bottom of each of said associated grooves.

Claim 4

Apparatus in accordance with claim 2 in which said molding recesses are so positioned in said belt that each such recess communicates with at least one of said extruding spaces whereby plastic material remaining in said molding recesses is integrally joined with plastic material extruded into at least one of said extruding spaces.

Claim 5

Apparatus in accordance with claim 1 in which at least some of the projections formed in said exit lip have a length greater than that required to penetrate the full depth of the associated grooves of said belt whereby to define above the ribs adjoining said associated grooves extruding spaces of predetermined vertical dimension through which plastic material will be extruded from said nozzle in the form of a plurality of parallel continuous strips having thicknesses corresponding with said predetermined vertical dimension and lying on each of said ribs adjoining associated grooves.

Claim 6

Apparatus in accordance with claim 4 in which said molding recesses are so positioned in said belt that each such recess communicates with at least one of said extruding spaces whereby plastic material remaining in said molding recesses is integrally joined with plastic material extruded into at least one of said extruding spaces.

Claim 7

Apparatus for molding plastic articles comprising an endless belt, means for continuously driving said belt longitudinally through an endless path, said belt having formed in one surface thereof a plurality of alternating ribs and grooves extending lengthwise of said path of said belt, at least some of the surface portions of said ribs and grooves having a plurality of longitudinally spaced discrete molding recesses sunk therein, at least some of said molding recesses being in the form of elongated shallow troughs having widths and depths only a small fraction of the lengths thereof, and means for supplying plastic material in moldable condition under pressure to said surface of said belt in which said ribs and grooves are formed including A nozzle having spaced parallel lips defining a narrow slitlike opening with the lengthwise dimension of said opening extending transversely of the path of travel of said belt whereby one of said lips constitutes an entrance lip and the other of said lips constitutes an exit lip as related to the travel of said belt through said endless path, means for positioning said entrance and exit lips in contact with the surface of said belt in which said ribs and grooves are formed, said entrance lip having a contour defined by alternating notches and projections formed in said entrance lip such as to engage with a snug sliding fit all surfaces of said ribs and grooves and said lip having a dimension in the direction of travel of said belt which is greater than the maximum effective dimension in said direction of any of said discrete molding recesses, whereby successive portions of said belt may travel beneath said entrance lip and into the plastic material within said nozzle without leakage of plastic material between said belt and said entrance lip, and said exit lip having a contour defined by alternating notches and projections formed in said exit lip such as to engage with a snug sliding fit at least a portion of those surfaces of said ribs and grooves in which said molding recesses are sunk, whereby as successive portions of said belt travel beneath said exit lip said exit lip will scrape plastic material off of the surfaces which are engaged by said exit lip while leaving plastic material remaining in all of said molding recesses.

Claim 8

Apparatus for molding plastic articles comprising an endless belt, means for continuously driving said belt longitudinally through an endless path, said belt having formed in one surface thereof a plurality of alternating ribs and grooves extending lengthwise of said path of said belt, at least some of the surface portions of said ribs and grooves having a plurality of longitudinally spaced discrete molding recesses sunk therein, at least some of said molding recesses being in the form of elongated shallow troughs having widths and depths only a small fraction of the lengths thereof, and means for supplying plastic material in moldable condition under pressure to said surface of said belt in which said ribs and grooves are formed including A nozzle having spaced parallel lips defining a narrow slitlike opening with the lengthwise dimension of said opening extending transversely of the path of travel of said belt whereby one of said lips constitutes an entrance lip and the other of said lips constitutes an exit lip as related to the travel of said belt through said endless path, means for positioning said entrance and exit lips in contact with the surface of said belt in which said ribs and grooves are formed, said entrance lip having a contour defined by alternating notches and projections formed in said entrance lip such as to engage with a snug sliding fit all surfaces of said ribs and grooves and said lip having a dimension in the direction of travel of said belt which is greater than the maximum effective dimension in said direction of any of said discrete molding recesses, whereby successive portions of said belt may travel beneath said entrance lip and into the plastic material within said nozzle without leakage of plastic material between said belt and said entrance lip, and said exit lip having a contour defined by alternating notches and projections formed in said exit lip such as to engage with a snug sliding fit at least a portion of those surfaces of said ribs and grooves in which said molding recesses are sunk, whereby as successive portions of said belt travel beneath said exit lip said exit lip will scrape plastic material off of the surfaces which are engaged by said exit lip while leaving plastic material remaining in all of said molding recesses.

Claim 9

Apparatus in accordance with claim 6 in which at least some of the projections formed in said exit lip have a length insufficient to penetrate the full depth of the associated grooves of said belt whereby to define in the lower portions of said associated grooves a plurality of extruding spaces of predetermined vertical dimension through which said plastic material will be extruded from said nozzle in the form of a plurality of parallel continuous strips of thicknesses corresponding with said predetermined vertical dimension and lying in the bottom of each of said associated grooves.

Claim 10

Apparatus in accordance with claim 7 in which said molding recesses are so positioned in said belt that each such recess communicated with at least one of said extruding spaces whereby plastic material remaining in said molding recesses is integrally joined with plastic material extruded into at least one of said extruding spaces.

Claim 11

Apparatus in accordance with claim 6 in which at least some of the projections formed in said exit lip have a length greater than that required to penetrate the full depth of the associated grooves of said belt whereby to define above the ribs adjoining said associated grooves extruding spaces of predetermined vertical dimension through which plastic material will be extruded from said nozzle in the form of a plurality of parallel continuous strips having thicknesses corresponding with said predetermined vertical dimension and lying on each of said ribs adjoining associated grooves. 10, Apparatus in accordance with claim 9 in which said molding recesses are so positioned in said belt that each such recess communicates with at least one of said extruding spaces whereby plastic material remaining in said molding recesses is integrally joined with plastic material extruded into at least one of said extruding spaces.

Claim 12

Apparatus in accordance with claim 6 in which the grooves formed in said belt are defined by a generally horizontally disposed bottom wall and opposed upwardly diverging sidewalls, in which the ribs formed in said belt are defined by the sidewalls of two adjacent grooves and a generally horizontally disposed top wall, and in which those of said molding recesses which are in the form of elongated troughs include portions which are sunk into the sidewalls of at least some of said grooves and extend upwardly from the bottom wall of each of those grooves in which said portions of said moLding recesses are sunk.

Claim 13

Apparatus in accordance with claim 3 in which means is provided in the path of said belt in a zone downstream of said nozzle for converting the plastic material in said molding recesses and in said continuous strips from moldable condition to solid condition, and in which means is provided in the path of said belt in a zone further downstream of said nozzle for engaging and removing said plastic material in solid condition from said belt, said last named means including a rotatable roll having plurality of circumferential ribs so spaced that one of said circumferential ribs will engage each of said continuous strips of plastic material and carry said strips away from said belt with the solidified plastic material from said molding recesses projecting into the spaces between circumferential ribs on said rotatable roll.

Claim 14

Apparatus in accordance with claim 12 in which there is provided means for supplying a continuous web of flexible sheet material having adhesive material on one surface thereof, and means for pressing said surface of said web into adhesive engagement with said strips of plastic material while said strips are being carried by said rotatable roll.

Claim 15

Apparatus in accordance with claim 5 in which there is provided means for guiding a continuous web of flexible sheet material into face-to-face contact with said strips of plastic material while they lie on the ribs of said belt, and means for securing said strips to said web.

Claim 16

Apparatus in accordance with claim 14 in which said means for securing said strips to said web includes means for applying adhesive material to one surface of said web and means for pressing said surface of said web against said strips.

Claim 17

Apparatus in accordance with claim 14 in which said means for securing said strips to said web includes a plurality of pressure rolls for pressing said web against said strips while the plastic material of which said strips consist is in moldable condition.

Claim 18

Apparatus in accordance with claim 1 specifically designed for the manufacture of molded plastic hooks, wherein at least some of said molding recesses are in the form of troughs each having a portion extending generally vertically with respect to the bottoms of said grooves and a portion extending generally transversely with respect to the bottoms of said grooves, said last-named portion having a closed end to define the free end of a hook molded therein.

Claim 19

Apparatus in accordance with claim 1 specifically designed for the manufacture of molded plastic loops, wherein at least some of said molding recesses are in the form of troughs each having two spaced portions extending generally vertically with respect to the bottoms of said grooves and a portion which serves to interconnect said two spaced portions and which extends generally horizontally with respect to the bottoms of said grooves.

Claim 20

Apparatus in accordance with claim 2 specifically designed for the manufacture of molded plastic hooks integral with and extending generally vertically with respect to the parallel continuous strips of plastic material extruded into the extruding spaces at the bottoms of said grooves, wherein at least some of said molding recesses are in the form of troughs each having a portion communicating with one of said extruding spaces and extending generally vertically with respect to the bottoms of said grooves and a portion extending generally horizontally with respect to the bottoms of said grooves, said last-named portion having a closed end to define the free end of a hook molded therein.

Claim 21

Apparatus in accordance with claim 2 specifically designed for the manufacture of molded plastic loops integral with and extending generally vertically with respect to the parallel continuous strips of plastic material extruded into the extruding spaces at the bottoms of said grooves, wherein at least some of said molding recesses are in the form of troughs each having two spaced portions communicating with at leaSt one of said extruding spaces and extending generally vertically with respect to the bottoms of said grooves and a portion which serves to interconnect said two spaced portions and which extends generally horizontally with respect to the bottoms of said grooves.

Claim 22

Apparatus in accordance with claim 4 specifically designed for the manufacture of molded plastic hooks integral with and extending generally vertically with respect to the parallel continuous strips of plastic material extruded into the extruding spaces above the ribs of said belt, wherein at least some of said molding recesses are in the form of troughs each having a portion communicating with one of said extruding spaces and extending generally vertically with respect to the bottoms of said grooves and a portion extending generally horizontally with respect to the bottoms of said grooves, said last-named portion having a closed end to define the free end of a hook molded therein.

Claim 23

Apparatus in accordance with claim 4 specifically designed for the manufacture of molded plastic loops integral with and extending generally vertically with respect to the parallel continuous strips extruded into the extruding spaces above the ribs of said belt, wherein at least some of said molding recesses are in the form of troughs each having two spaced portions communicating with at least one of said extruding spaces and extending generally vertically with respect to the parallel continuous strips extruded into the extruding spaces above the ribs of said belt, wherein at least some of said molding recesses are in the form of troughs each having two spaced portions communicating with at least one of said extruding spaces and extending generally vertically with respect to the bottoms of said grooves and a portion which serves to interconnect said two spaced portions and which extends generally horizontally with respect to the bottoms of said grooves.

Claim 24

Apparatus in accordance with claim 13 specifically designed for the manufacture of a product comprising said continuous web of flexible sheet material with said strips of plastic material secured by said adhesive engagement to one surface of said flexible sheet material and with molded plastic hooks integral with and extending generally vertically with respect to said strips of plastic material, said product being useful as the hook part of a flexible fastener of the hook-and-loop type, wherein at least some of said molding recesses are in the form of elongated troughs each having a portion extending generally vertically with respect to the bottoms of the grooves in said belt and one end of which portion communicates with one of said extruding spaces in the lower portions of said grooves of said belt, and each of said troughs having a portion extending generally horizontally with respect to said one extruding space, said last-named portion having a closed end to define the free end of a hook molded therein.

Claim 25

Apparatus in accordance with claim 14 specifically designed for the manufacture of a product comprising said continuous web of flexible sheet material with said strips of plastic material secured to one surface of said flexible sheet material and with molded plastic hooks integral with and extending generally vertically with respect to said strips of plastic material, said product being useful as the hook part of a flexible fastener of the hook-and-loop type, wherein at least some of said molding recesses are in the form of elongated troughs each having a portion extending generally vertically with respect to the bottoms of the grooves in said belt and one end of which portion communicates with one of said extruding spaces above the ribs of said belt, and each of said troughs having a portion extending generally horizontally with respect to said extruding space, said last named portion having a closed end to define the free end of a hook molded therein.