Tanged screw thread insert with improved removability

Abstract

A helical-shaped insert to engage a threaded fastener to a receiving member includes a helical coil having a plurality of coil sections having inner and outer surfaces forming a thread shape, and opposing first and second coil end sections. A removable tang extends radially inward from the first coil end section. A continuously curved surface at a finished end of the second coil end section forms a tangent point where the continuously curved surface tangentially meets the second coil end section outer surface.

1 . A thread insert, comprising:
 a helical-shaped insert defining a plurality of coil sections including opposing first and second coil end sections, each coil section having an inner surface and an outer surface defining a thread shape;   a notch defined between the inner and outer surfaces in the first coil end section, the first notch proximate to a tang extending inwardly from the first coil end section;   a continuously curved convex surface at a second coil terminal end section that tangentially meets the outer surface of the second coil end section, wherein the intersection between the continuously curved convex surface and the outer surface intersects at an obtuse angle; and   a recess defined in the second coil section proximate to the continuously curved surface, the recess having a contact surface operable to assist in removal of the insert from an installed position upon the application of force on the contact surface in a clockwise direction.   
     
     
         2 . The thread insert of  claim 1 , wherein each of the coil sections include a predetermined outer diameter, and each of the coil sections is disposed about a common coil centerline. 
     
     
         3 . The thread insert of  claim 1 , wherein the recess further includes an inner wall positioned at the common coil centerline. 
     
     
         4 . The thread insert of  claim 3 , where the recess further comprises:
 a contact surface; and   a radial corner joining the inner wall to the contact surface.   
     
     
         5 . A method for creating a thread insert, the thread insert including a helical-shaped coil defining a plurality of coil sections including opposing first and second coil end sections, each coil section having an inner and an outer surface, the method comprising:
 creating a continuously curved convex surface at a second coil terminal end section;   joining the continuously curved surface to the outer surface of the second coil end section to create a tangent point where the continuously curved surface meets the outer surface of the second coil end section at an obtuse angle;   creating a recess in the second coil end section proximate to the continuously curved surface, said recess including an inner wall proximate positioned substantially at a coil centerline; and   positioning a contact surface of the recess to assist in removing the insert from an installed position.   
     
     
         6 . The method of  claim 5 , further comprising forming a contact surface with said recess, said contact surface intersecting said inner wall. 
     
     
         7 . The method of  claim 6 , further comprising creating a notch proximate to a bend joining the tang to the first coil end section. 
     
     
         8 . The method of  claim 5 , further comprising tangentially joining the continuously curved surface to the inner surface of the second coil end section to operably create a second tangent point. 
     
     
         9 . The method of  claim 5 , further comprising creating a thread shape at each of the outer and inner surfaces of the coil sections. 
     
     
         10 . The method of  claim 5 , wherein tangentially joining the continuously curved surface to the outer surface of the second coil end section forms a non-sharp tangent point. 
     
     
         11 . A thread insert, comprising:
 a helical-shaped insert defining a plurality of coil sections including opposing first and second coil end sections, each coil section having an inner surface and an outer surface defining a thread shape;   a notch disposed between the inner and outer surfaces in the first coil end section, the first notch proximate to a tang extending inwardly from the first coil end section;   a continuously curved convex surface at a second coil terminal end section that tangentially meets the outer surface of the second coil end section, wherein the intersection between the continuously curved convex surface and the outer surface intersects at an obtuse angle;   a recess defined by the second coil section proximate to the continuously curved surface, the recess having a contact surface configured to accept a force to rotate the insert in a clockwise direction and operable to assist in removal of the insert from an installed position; and   wherein the tang is removable from the insert by mechanical failure at one of the first or second notch.   
     
     
         12 . The thread insert of  claim 11 , wherein each of the coil sections include a predetermined outer diameter, and each of the coil sections is disposed about a common coil centerline. 
     
     
         13 . The thread insert of  claim 11 , wherein the recess further includes an inner wall positioned substantially at the common coil centerline. 
     
     
         14 . The thread insert of  claim 13 , where the recess further comprises a radial corner joining the inner wall to the contact surface. 
     
     
         15 . The thread insert of  claim 1 , wherein the tang extends from the first coil end section, said tang being removable upon the fracture of the insert at the notch. 
     
     
         16 . The thread insert of  claim 1 , wherein the notch is disposed in the first coil end section proximate to the tang and positioned between the inner and outer surfaces. 
     
     
         17 . The thread insert of  claim 1 , wherein each of the inner and outer surfaces define a thread-shape. 
     
     
         18 . The thread insert of  claim 1 , further comprising a second tangent point operably created where the continuously curved surface tangentially meets the inner surface of the second coil end section. 
     
     
         19 . A thread insert, comprising:
 a helical-shaped insert defining a plurality of coil sections including opposing first and second coil end sections, each coil section having an inner surface and an outer surface defining a thread shape, said inner surface defining a recess therein, said recess having a contact surface which is substantially perpendicular to a coil section centerline;   a removable tang radially extending inwardly from the first coil end section;   a rounded finished terminal end of the second coil end section, the finished terminal end having a continuously curved transverse convex surface at the rounded finished terminal end to ease removal of said insert that blends the inner surface and the outer surface of the second coil end section;   a tangent point located where the continuously transverse curved convex surface tangentially meets the outer surface of the second coil end section at an obtuse angle; and   a notch disposed in the first coil end section proximate to the tang and positioned between the inner and outer surfaces, wherein the tang is removable from the insert by mechanical failure at the notch.   
     
     
         20 . The thread insert of  claim 19 , further comprising a second tangent point operably created where the continuously curved surface tangentially meets the inner surface of the second coil end section. 
     
     
         21 . The thread insert of  claim 19 , wherein each of the coil sections include a predetermined outer diameter, and each of the coil sections is disposed about a common coil centerline.