Techniques for stiffening shoe insoles

A method for imparting a permanent predetermined shape to an insole at the ball and arch curves comprising:

• supporting the insole in said predetermined shape with predetermined curves at the ball and the arch;
• causing an externally activatable material to cure to a hardened state on the shank region of the insole and to adhere thereto while maintaining the insole in the predetermined shape whereby curing of the material will reinforce the insole and will retain the insole in the predetermined shape in readiness for subsequent shoe manufacturing operations;
• and
• heating the insole to disrupt its elastic memory and effecting said curing while the insole is maintained in its heated state.

A method for reinforcing the shank region of a sole insole with a shank stiffener and for shaping said insole to a predetermined longitudinally extending shape comprising:

• providing a pre-molded insole having a molded shape which substantially approximates the predetermined longitudinal shape;
• placing a flexible, deformable shank strip on the surface of the shank region of the insole, the shank strip being formed from an activatable resin;
• supporting the insole at the heel, ball and arch regions by supporting means arranged to support each region at a predetermined heightwise datum relative to the others, said datum each being disposed along and defining portions of said predetermined longitudinal shape;
• confining the insole against said predetermined datum locations to confine the insole to said predetermined longitudinal shape;
• and
• activating the shank strip while the insole is so held to cause the strip to cure on and adhere to the insole whereby, when cured, the shank strip will retain the insole in said predetermined longitudinal shape.

A method for repeatedly shaping a plurality of insoles to a predetermined longitudinal shape and for stiffening the shank region of said insoles in said predetermined longitudinal shape comprising:

• providing a plurality of pre-molded insoles having molded shapes which substantially approximate said predetermined longitudinal shape;
• providing at least three longitudinally spaced datum surfaces arranged to define said predetermined longitudinal shape of the insole;
• holding selected regions of the insole against said datum surfaces thereby to hold the insole in said predetermined longitudinal shape;
• while so holding the insole, causing an initially flexible, externally activatable material to cure to a rigid state on the shank region of the insole and to adhere to the shank region of the insole whereby the material will cure to said predetermined configuration and will, when cured, retain the insole in said predetermined longitudinal shape;
• removing said insole with cured, adhered material from said datum surfaces;
• applying another of said pre-molded insoles to said datum surfaces in readiness to shape said insole to said predetermined longitudinal shape.