Mold and method for injection molding a sole onto a shoe upper

In a mold for injection molding a sole onto an upper, the mold comprising longitudinally extending ring plate means which define the mouth of the mold in which a lasted shoe upper may be sealingly engaged, the inner faces of said ring plate means having the contour of the sides of the peripheral portion of the bumper to be molded, and a sole plate the upper surface of which is provided with the design to be formed on the bottom of the sole, said sole plate being adapted for movement towards and away from the bottom of a lasted shoe upper positioned in the mouth of the mold, the improvement comprising,

• the ring plate means having a generally concave inner surface at its upper portion and
• the sole plate compirising a fin extending upwardly about its periphery, the inner surface of said fin being generally concave and generally forming a continuation of the lower portion of said generally concave inner surface of the ring plate means when the sole plate is in a lower position and the upper portion of said fin being spaced inwardly from said generally concave inner surface of the ring plate means when the sole plate is in an upper position, whereby said fin forms a peripheral groove adjacent to the lower side of a first sole part which is injection molded when the sole plate is in said upper position and the inner generally concave surface of said fin forms a downwardly extending continuation of the peripheral face of the bumper of the first sole part on a second sole part which is injection molded when the sole plate is in said lower position.