Insert molding apparatus and method

Abstract

An apparatus for making a molded article containing an insert includes an upper mold half and a lower mold half for mating with the upper mold half to provide a mold cavity therein. Either mold half can include a recess, an elevator opening in a lower portion of the recess, and an inwardly directed lip at an upper portion of the elevator opening. An elevator mechanism is provided which includes a lifter for supporting an insert to be secured to the article during a molding operation, and a lifting arrangement for raising and lowering the lifter through the elevator opening such that a peripheral edge of the insert supported on the lifter is clamped between the lifter and the lip when the lifting arrangement raises the lifter.

What is claimed is:  
     
         1 . An apparatus for insert molding, comprising: 
 an upper mold half;    a lower mold half for mating with said upper mold half to provide a molded part cavity therein;    at least one of said lower mold half and said upper mold half including: 
 an elevator opening;  
 an inwardly directed lip at a cavity side of said elevator opening; and  
 an elevator mechanism including: 
 a lifter for supporting an insert to be secured to a molded article during a molding operation, and  
 a lifting arrangement for raising and lowering said lifter through said elevator opening such that a peripheral edge of the insert supported on said lifter is clamped between said lifter and said lip when said lifting arrangement moves said lifter adjacent said inwardly directed lip.  
 
   
     
     
         2 . The apparatus according to  claim 1 , wherein said lifting arrangement includes: 
 a base positioned outside a respective said mold half on a side opposite said molded part cavity; and    a cylinder mounted to said base and including a movable piston rod connected with said lifter for raising and lowering said lifter.    
     
     
         3 . The apparatus according to  claim 2 , wherein said base includes a recess for mounting said cylinder.  
     
     
         4 . The apparatus according to  claim 1 , further comprising a retainer removably connected to said respective mold half within said elevator opening, said retainer including a dam flush with and removable from an inner wall defining said elevator opening, and said retainer further including said inwardly extending lip connected to an end of said dam.  
     
     
         5 . The apparatus according to  claim 4 , wherein said retainer further includes an outwardly extending connector connected with an opposite end of said dam and removably secured to a surface of the respective mold half.  
     
     
         6 . The apparatus according to  claim 1 , wherein said lifting arrangement includes: 
 a first slide plate having a first inclined cam surface, said lifter being connected to said first slide plate;    a second slide plate having a second inclined cam surface in contact with said first inclined cam surface; and    a moving arrangement for sliding said second slide plate relative to said first slide plate in order to raise and lower said first slide plate and said lifter.    
     
     
         7 . The apparatus according to  claim 1 , which is adapted for molding shoe insoles and wherein: 
 said lower mold half includes: 
 two lower mold cavities corresponding to left and right insoles to be molded;  
 one said elevator opening in a lower portion of each said lower mold cavity; and  
 one said inwardly directed lip at an upper portion of each said elevator opening;  
   said elevator mechanism includes two said lifters for supporting an insert in correspondence with each said lower mold cavity; and    said lifting arrangement raises and lowers said two lifters such that a peripheral edge of each insert supported on each said respective lifter is clamped between said lifter and the respective lip when said lifting arrangement raises said lifters.    
     
     
         8 . A method for insert molding, comprising the steps of: 
 providing an upper mold half and a lower mold half for mating with said upper mold half to provide a molded part cavity therein, at least one of said lower mold half and said upper mold half including an elevator opening, and an inwardly directed lip at a cavity side of said elevator opening;    supporting an insert to be secured to a molded article on a lifter positioned in said elevator opening during a molding operation;    moving said lifter such that a peripheral edge of the insert supported on said lifter is clamped between said lifter and said lip when said lifting arrangement moves said lifter adjacent said inwardly directed lip;    supplying a molding material to said cavity; and    closing said mold halves until said article is formed.    
     
     
         9 . The method according to  claim 8 , further comprising the steps of: 
 opening said mold halves after said article has been formed;    moving said lifter such that said peripheral edge of the insert supported on said lifter is no longer clamped between said lifter and said lip; and    removing said formed article from said mold.    
     
     
         10 . The method according to  claim 8 , further including the step of applying a barrier layer on said insert prior to supporting said insert on said lifter to prevent said molding material from penetrating through said insert.  
     
     
         11 . The method according to  claim 8 , further comprising the step of maintaining the insert in a flat configuration while moving the lifter to clamp the insert and prior to closing said mold halves.  
     
     
         12 . The method according to  claim 11 , wherein said step of maintaining includes the step of placing a support, having approximately the same shape as the insert, on the insert prior to raising the lifter in order to maintain the insert in a flat configuration during the clamping operation, and then removing the support prior to closing the mold halves together.  
     
     
         13 . A molded article containing an insert and being produced by the method of  claim 8 .  
     
     
         14 . An insole for use with footwear, comprising: 
 a first layer having a lower shallow recess and a first property selected from the group consisting of cushioning, hardness, density, resilience and color; and    an insert secured in said recess and being made of a material of a second said property which is different from said first said property, said insert having an upper surface secured to said first layer in said recess, and a peripheral portion of said upper surface being free and unsecured to said first layer in said recess.    
     
     
         15 . The insole according to  claim 14 , wherein said first layer includes: 
 a forefoot portion extending at least to metatarsals of a foot;    a heel portion;    a mid portion connecting together said forefoot portion and said heel portion;    an upper surface extending along said forefoot, mid and heel portions and on which a person stands; and    a lower surface extending along said forefoot, mid and heel portions, said lower surface including said lower shallow recess.    
     
     
         16 . The insole according to  claim 14 , wherein said insert has a barrier layer on an upper surface thereof to prevent a molding material from penetrating into said insert during a molding operation.