Method for injection-molding an orthopedic device and product of the method

Abstract

An injection-molded thermoplastic device having a field of injection-molded hooks integrally formed in predetermined areas on the device during the injection-molding of the device for releasable attachment to a strap with loops.

I claim:  
     
       1. A unitary one-piece injection-molded relatively rigid thermoplastic device having flexible hooks adapted to be releasably attachable to at least one associated cooperative loop-bearing member, the device comprising: 
       at least one relatively rigid wall member intended to provide a function, said wall member being injection-molded; and  
       a field of flexible injection-molded hooks formed in their hook shape substantially simultaneously and integrally with said functional wall member during the injection-molding of the wall member on at least one predetermined area thereof, said field of hooks being structured and dimensioned for releasable attachment to the at least one associated cooperative member, said field of hooks comprising spaced rows each of one-way facing hooks, such that in each row all hooks face in the same direction and such that in at least some adjacent rows the hooks face in different directions, and said predetermined area of said field of hooks comprising substantially less than the total area of said injection-molded wall member.  
     
     
       2. The device in accordance with claim  1 , wherein the hooks have a radius such that the shear force required to release the loops of the associated cooperative member is substantially greater than the tension force required to release the loops. 
     
     
       3. The device in accordance with claim  2 , wherein the thermoplastic material of the device has a memory sufficient to cause the hooks to return substantially to their original shape after being removed from the mold and is of sufficient flexibility to allow the hooks to bend during removal from the mold and thereafter during the release of the loops. 
     
     
       4. The device in accordance with claim  3 , wherein the thermoplastic material is a polypropylene. 
     
     
       5. The device in accordance with claim  4 , wherein the polypropylene is an unfilled polyester blend of 50% homopolymer and 50% copolymer having a melt-flow index from 150° to 175° C. and a flex modulus from 130,000 to 200,000 psi. 
     
     
       6. The device in accordance with claim  3  wherein said wall member may have an arcuate section and wherein said field of hooks is integrally formed in a predetermined area located on any desired portion of the wall member, including the arcuate section. 
     
     
       7. The device as in claim  6 , wherein the device is an orthopedic device. 
     
     
       8. The device as in claim  7 , wherein said wall member has an arcuate transverse cross-sectional shape sufficient to conform generally to the circumferential contour of the inner or outer side of a lower leg and ankle; and 
       wherein said associated cooperative loop-bearing member is releasably attachable to said field of hooks to hold the wall member against the inner or outer side of the lower leg and ankle.  
     
     
       9. A unitary one-piece injection molded relatively rigid thermoplastic device having hooks adapted to be releasably attachable to at least one associated cooperative loop-bearing member, the device comprising: 
       at least one relatively rigid wall member intended to provide a function, said wall member being injection-molded; and  
       a field of injection-molded single tip hooks, said field having a length and a width, said field comprising hooks interspersed in both the length and the width of the field, said field of hooks being structured and dimensioned for releasable attachment to the at least one associated cooperative member, said hooks being oriented within said field such that the tips of said hooks do not all face in the same direction, such that said orientation of said hooks facilitates secure attachment of said field of hooks to said cooperative member, said field of hooks facing in different directions being formed in their hook shape substantially simultaneously and integrally with said functional wall member on at least one predetermined area thereof.  
     
     
       10. The device of claim  9 , wherein said single tip hooks are oriented such that a substantial number of hook tips face in a first direction and a substantial number of other hook tips face in a different direction, such that said differently facing hook tips facilitate secure attachment of said field of hooks to the cooperative member. 
     
     
       11. The device of claim  10 , wherein said hooks are arranged in rows. 
     
     
       12. The device of claim  11 , wherein at least some hook tips in one or more rows face in a direction opposite the direction of some hook tips in an adjacent row. 
     
     
       13. The device of claim  12 , wherein hook tips in alternating rows face in opposite directions. 
     
     
       14. The device of claim  9 , wherein said predetermined area of said field of hooks comprises substantially less than the total area of said injection-molded wall member. 
     
     
       15. The device of claim  14  wherein the hooks have a radius such that the shear force required to release the loops of the associated cooperative member is substantially greater than the tension force required to release the loops. 
     
     
       16. The device of claim  15  wherein the thermoplastic material of the device has a memory sufficient to cause the hooks to return substantially to their original shape after being removed from the mold and is of sufficient flexibility to allow the hooks to bend during removal from the mold and thereafter during the release of the loops. 
     
     
       17. The device of claim  16 , wherein the thermoplastic material is a polypropylene. 
     
     
       18. The device of claim  17 , wherein the polypropylene is an unfilled polyester blend of 50% homopolymer and 50% copolymer having a melt-flow index from 150° to 175° C. and a flex modulus from 130,000 to 200,000 psi. 
     
     
       19. The device of claim  14 , wherein said wall member may have an arcuate section and wherein said field of hooks is integrally formed in a predetermined area located on any desired portion of the wall member, including the arcuate section. 
     
     
       20. The device of claim  19 , wherein the device is an orthopedic device. 
     
     
       21. The device of claim  20 , wherein said wall member has an arcuate transverse cross-sectional shape sufficient to conform generally to the circumferential contour of the inner or outer side of the lower leg and ankle; and 
       wherein said associated cooperative loop-bearing member is releasably attachable to said field of hooks to hold the wall member against the inner or outer side of the lower leg and ankle.  
     
     
       22. A unitary one- piece injection - molded relatively rigid thermoplastic device having flexible hooks adapted to be releasably attachable to at least one associated cooperative loop - bearing member, the device comprising:    
         at least one relatively rigid wall member intended to provide a function, said wall member being injection - molded; and    
         a field of flexible injection - molded hooks formed in their hook shape substantially simultaneously and integrally with said functional wall member during the injection - molding of the wall member on at least one predetermined area thereof said field of hooks being structured and dimensioned for releasable attachment to the at least one associated cooperate member, said field of hooks having a length and a width, said field comprising hooks interspersed in both the length and the width of the field, and said pre - determined area of said field of hooks comprising substantially less than the total area of said injection molded wall member.    
     
     
       23. The device of claim  22  wherein said hooks within said field each have one or more hook tips.  
     
     
       24. The device of claim  23  wherein not all hook tips in said field face in the same direction.  
     
     
       25. The device of claim  24  wherein at least some adjacent hooks within said field have hook tips facing in different directions.  
     
     
       26. The device of claim  25  wherein said field comprises spaced rows of hooks, and wherein at least some hook tips in a row face in a different direction from at least some hook tips in an adjacent row.  
     
     
       27. The device in accordance with claim  22 , wherein the hooks have a radius such that the shear force required to release the loops of the associated cooperative member is substantially greater than the tension force required to release the hoops.  
     
     
       28. The device in accordance with claim  27 , wherein the thermoplastic material of the device has a memory sufficient to cause the hooks to return substantially to their original shape after being removed from the mold and is of sufficient flexibility to allow the hooks to bend during removal from the mold and thereafter during the release of the loops.  
     
     
       29. The device in accordance with claim  28 , wherein the thermoplastic material is a polypropylene.  
     
     
       30. The device in accordance with claim  29 , wherein the polypropylene is an unfilled polyester blend of  50 %  homopolymer and  50   %  copolymer having a melt - flow index from  150 ° and  175 ° C. and a flex modulus from  130 , 000  to  200 , 000  psi.    
     
     
       31. The device in accordance with claim  28  wherein said wall member may have an arcuate section and wherein said field of hooks is integrally formed in a predetermined area located on any desired portion of the wall member, including the arcuate section.  
     
     
       32. The device as in claim  31 , wherein the device is an orthopedic device.  
     
     
       33. The device as in claim  32 , wherein said wall member has an arcuate transverse cross- sectional shape sufficient to conform generally to the circumferential contour of the inner or outer side of a lower leg and ankle; and    
         wherein said associated cooperative loop - bearing member is releasably attachable to said field of hooks to hold the wall member against the inner or outer side of the lower leg and ankle.    
     
     
       34. A unitary one- piece injection - molded relatively rigid thermoplastic device having hooks adapted to be releasably attachable to at least one associated cooperative loop - bearing member, the device comprising:    
         at least one relatively rigid wall member intended to provide a function, said wall member being injection - molded; and    
         a field of injection - molded hooks, said field having a length and a width, said field comprising hooks interspersed in both the length and the width of the field, said field of hooks being structured and dimensioned for releasable attachment to the at least one associated cooperative loop - bearing member, said field of hooks being formed in their hook shape substantially simultaneously and integrally with said functional wall member on at least one predetermined area thereof.    
     
     
       35. The device of claim  34  wherein said hooks within said field each have one or more hook tips.  
     
     
       36. The device of claim  35  wherein said hook tips are oriented within said field such that not all hook tips in said field face in the same direction, such that said orientation of said hook tips facilitates secure attachment of said field of hooks to said cooperative member.  
     
     
       37. The device of claim  36  wherein said hooks in said field are single tip hooks.  
     
     
       38. The device of claim  36 , wherein said hooks are oriented such that a substantial number of hook tips face in a first direction and a substantially number of other hook tips face in a different direction, such that said differently facing hook tips facilitate secure attachment of said field of hooks to the cooperative member.  
     
     
       39. The device of claim  38 , wherein said hooks are arranged in rows.  
     
     
       40. The device of claim  39 , wherein at least some hook tips in one or more rows face in a direction different from the direction of some hook tips in an adjacent row.  
     
     
       41. The device of claim  40 , wherein hook tips in at least some adjacent rows face in opposite directions.  
     
     
       42. The device of claim  36 , wherein said predetermined area of said field of hooks comprises substantially less than the total area of said injection- molded wall member.    
     
     
       43. The device of claim  42  wherein the hooks have a radius such that the shear force required to release the loops of the associated cooperative member is substantially greater than the tension force required to release the loops.  
     
     
       44. The device of claim  43  wherein the thermoplastic material of the device has a memory sufficient to cause the hooks to return substantially to their original shape after being removed from the mold and is of sufficient flexibility to allow the hooks to bend during removal from the mold and thereafter during the release of the loops.  
     
     
       45. The device of claim  44 , wherein the thermoplastic material is a polypropylene.  
     
     
       46. The device of claim  45 , wherein the polypropylene is an unfilled polyester blend of  50 %  homopolymer and  50   %  copolymer having a melt - flow index from  150 ° to  175 ° C. and a flex modulus from  130 , 000  to  200 , 000  psi.    
     
     
       47. The device of claim  42 , wherein said wall member may have an arcuate section and wherein said field of hooks is integrally formed in a predetermined area located on any desired portion of the wall member, including the arcuate section.  
     
     
       48. The device of claim  47 , wherein the device is an orthopedic device.  
     
     
       49. The device of claim  48 , wherein said wall member has an arcuate transverse cross- sectional shape sufficient to conform generally to the circumferential contour of the inner or outer side of the lower leg and ankle; and    
         wherein said associated cooperative loop - bearing member is releasably attachable to said field of hooks to hold the wall member against the inner or outer side of the lower leg and ankle.