Collapsible core using two sleeves and is spring loaded

Abstract

This invention is the first time two sleeves have been used to improve the manufacturability of the collapsible sections of this apparatus; this greatly improves the accuracy during manufacture and reliability during use.

1 . (canceled)  
   
   
       2 . (canceled)  
   
   
       3 . A collapsible core device for molding articles around said core device in a mold cavity, comprising: 
 a outer sleeve member having a plurality of outside wedge sections extending from a first base in an axial direction, said plurality of outside wedge sections defining a discontinuous first perimeter surrounding a channel;    a inner sleeve member having a plurality of inside wedge sections extending from a second base in an axial direction, said plurality of inside wedge sections defining a discontinuous second perimeter surrounding said central channel;    each of said inside wedge sections arranged between adjacent ones of said outside wedge sections; and    a center pin, slidable axially within said central channel to forcibly displace said first and inside wedge sections outwardly to form a substantially continuous perimeter defined by said first and inside wedge sections.    
   
   
       4 . The core device according to  claim 3 , wherein said outside wedge sections are tapered in a radially inward direction and said inside wedge sections are tapered in a radially outward direction.  
   
   
       5 . The core device according to  claim 3 , wherein said overall perimeter comprises a cylindrical surface with protruding threads.  
   
   
       6 . The core device according to  claim 5 , wherein at least said inside wedge sections comprise outside protuberances arranged around said second discontinuous perimeter, and further comprising a bushing surrounding said second discontinuous perimeter and including a surface for sliding over said protuberances to drive said inside wedge sections inwardly.  
   
   
       7 . The core device according to  claim 3 , wherein at least said inside wedge sections comprise outside protuberances arranged around said second discontinuous perimeter, and further comprising a bushing surrounding said second discontinuous perimeter and including a surface for sliding over said protuberances to drive said inside wedge sections inwardly.  
   
   
       8 . The core device according to  claim 3 , wherein said outside wedge sections are tapered in a radially inward direction and said inside wedge sections are tapered in a radially outward direction, wherein at least said inside wedge sections comprise outside protuberances arranged around said second discontinuous perimeter, and further comprising a bushing surrounding said second discontinuous perimeter and including a surface for sliding over said protuberances to drive said inside wedge sections inwardly.  
   
   
       9 . The core device according to  claim 3 , wherein said first base comprises a cap portion and said second base comprises a ring portion that is fittable into said cap portion.  
   
   
       10 . The core device according to  claim 9 , wherein said outside wedge sections are tapered in a radially inward direction and said inside wedge sections are tapered in a radially outward direction and said overall perimeter is a substantially continuous surface.