Die set and apparatus for in-situ molding of a separable fastener component

Claim 2

Apparatus for in situ formation of a plastic snap-fastener fitment in assembled relation with a porous substrate, comprising substrate-clamping means consisting of first and second dies having molding sides configurated for mutually registering and peripherally continuous contact with opposite sides of the porous substrate, said dies defining a mold cavity therebetween, and die-displacing means for moving said dies relative to each other between a first open position and a second position of clamped die-compression of substrate for at least a peripherally continuous outer limit of fitment definition, one of said dies having a cylindrical guide bore on an axis normal to the plane of said outer limit and centrally located within said outer limit, a ram reciprocably guided by said bore, said dies when clamped and said ram when advanced in said bore defining a fitment cavity which peripherally continuously surrounds at least the tip end of the ram and which also includes uncompressed pores of the substrate, means for delivering a predetermined charge of moldable plastic material to said cavity prior to ram advance in said cavity, ram-displacing means for compressing plastic material to fill said cavity, said ram-displacing means including an ultrasonic generator coupled for axially oscillating displacement of the tip end of said ram and stripper means engageable with said substrate to remove said fitment from at least one of said dies.

Claim 3

Apparatus according to claim 1, in which said ram-displacing means includes stop means for predetermined arrest of ram advance, and means coordinating excitation of said generator in such timed relation with ram advance as to terminate such excitation substantially upon an operation of said stop means.

Claim 4

Apparatus according to claim 2, in which said coordinating means includes a microprocessor connected to said ram-displacing means and programmed to assure continued application of ram-advancing force at the operative position of stop-means actuation, said continued application of force being for a period of time after termination of generator excitation and prior to a programmed retracting displacement of said ram.

Claim 5

Apparatus according to claim 1, in which said guide bore is lined with an elastomeric seal coacting with said ram, selectively operable means for axially compressing said seal for radially stressed sealing engagement to said ram, and means including a microprocessor connected for synchronized coordination of the advancing stroke of said ram-displacing means concurrently with actuation of said selectively operable means at least at the plastic-compression end of the advancing stroke of said ram.

Claim 6

Apparatus according to claim 4, in which said lining is of such axial extent in relation to the stroke of said ram that said ram is at all times guided by said seal.

Claim 7

Apparatus according to claim 5, in which ram surfaces engageable with said seal have polished finish.

Claim 8

Apparatus according to claim 1, in which said means for delivering a predetermined charge comprises a tubular guide for periodic advancing displacement of a rod of moldable plastic material, shear means coacting with said guide for severing a pellet of rod material from guided rod, a stop for limiting incremental rod advance for each operation of said shear means, and means for individually delivering the severed pellet into axial registration beneath said ram when said dies are in their relatively retracted position.

Claim 9

Apparatus according to claim 7, in which said tubular guide includes electrical heating means for softening plastic rod in approach to said shear means.

Claim 10

Apparatus according to claim 1, in which the cavity-defining region of one of said dies defines a bulbous snap-engageable portion of a snap-fastener component, and said stripper means including a hinged arm on a hinge axis parallel to the clamping plane and offset from axial alignment with said ram, said stripper means being engageable with the molded-fitment side of substrate material at a location in offset from the ram axis and opposed to the offset of said hinge.

Claim 11

Apparatus according to claim 9, in which said one die comprises upper and lower separable component parts each of which has cavity-defining contours, the upper component part having said guide bore, and the lower component part being also a part of the hinged structure of said stripper means.

Claim 12

Apparatus for in situ forming a premeasured pellet of plastic working material into a molded-plastic structural article on a sheet of porous substrate material, comprising a first die having a peripherally continuous annular substrate-clamping land surrounding an article-forming cavity surface, a second die having a peripherally continuous region at least conforming to the area of said land and surrounding a central anvil region, means for actuating said dies in relative axial reciprocation between positions of die separation and clamped sealing compression of the substrate, whereby substrate surrounded by the land-clamped annulus is uncompressed, said first die having a cylindrical horn-guide bore with at least the section area of said pellet and communicating with said cavity surface in alignment with said central anvil region, a cylindrical horn guided by said bore, reciprocating means for advancing and retracting said horn along a cylindrical path of alignment with said anvil region and interposed uncompressed substrate material, said reciprocating means including means for compressionally deforming the premeasured working material against uncompressed substrate material and against anvil rejection by direct vibratory excitation of the working material to melt the same and force its impregnation of substrate pores and otherwise to fill the included cavity volume established by and between said dies and interposed substrate and stripping means engageable with said substrate to remove said molded plastic article from at least one of said dies.

Claim 13

Apparatus for in situ forming a premeasured pellet of plastic working material into a molded-plastic structural article on a sheet of porous substrate material, comprising a first die having a peripherally continuous annular substrate-clamping land surrounding an article-forming cavity surface, a second die having a peripherally continuous region at least conforming to the area of said land and surrounding a central anvil region, means for actuating said dies in relative axial reciprocation between positions of die separation and clamped sealing compression of the substrate, whereby substrate surrounded by the land-clamped annulus is uncompressed, said first die having a cylindrical horn-guide bore with at least the section area of said pellet and communicating with said cavity surface in alignment with said central anvil region, a cylindrical horn guided by said bore, reciprocating means for advancing and retracting said horn along a cylindrical path of alignment with said anvil region and interposed uncompressed substrate material, said reciprocating means including means for compressionally deforming the premeasured working material against uncompressed substrate material and against anvil rejection by direct vibratory excitation of the working material to melt the same and force its impregnation of substrate pores and otherwise to fill the included cavity volume established by and between said dies and interposed substrate and stripping means engageable with said substrate to remove said molded plastic article from at least one of said dies.

Claim 14

Apparatus according to claim 11, in which said ram has sealed sliding guidance in said bore.

Claim 15

Apparatus according to claim 11, in which said land is a circular annulus, and in which said cavity surface has circular symmetry around and radially outward of said horn.

Claim 16

Apparatus according to claim 11, in which said land has a circular inner edge which is at radial offset from said path, whereby the molded-plastic product of horn-tip displacement into said cavity is a circular annulus extending at cavity-depth offset from the substrate material at impregnated integration therewith.

Claim 17

Apparatus according to claim 14, in which the mold cavity is characterized by a circumferentially continuous stud-defining bulbous formation contiguous to said circular inner edge.

Claim 18

Apparatus according to claim 14, in which the mold cavity is characterized by a circumferentially continuous depending socket-defining wall formation in axial overlap with and at radial offset from said bore.

Claim 19

Apparatus according to claim 11, in which said horn tip is geometrically configured to determine the internal socket contour of a socket component of a snap-fastener.

Claim 20

Apparatus according to claim 11, in which the area within the second-die area of conformance with said land is flat over substantially the entire area within the outer perimeter of conformance with said land, whereby molded plastic is relatively invisible on the flat side.

Claim 21

Apparatus according to claim 11, in which the area within the second-die area of conformance with said land is characterized by a peripherally continuous annular bead-defining cavity adjacent the inner edge of conformance with said land, whereby each of said dies has a perimeter-defining annular land and the annular bead provides a pleasing appearance on the non-functional side of the substrate.

Claim 22

Apparatus according to claim 19, in which said anvil region is substantially flat and circular and is of at least the sectional area of said horn.

Claim 23

Apparatus according to claim 20, in which said anvil region is recessed from the geometric plane of said peripherally continuous land-conforming area, and in which said bead-defining cavity is recessed with respect to said anvil region.

Claim 24

Apparatus according to claim 20, in which said substantially flat surface is characterized by an intaglio or relief design.