Apparatus for injecting plastic or rubber soles to shoe uppers

Claim 1

APPARATUS FOR MAKING SHOES BY INJECTION MOLDING COMPRISING A SOLE PLATE, A MOLD RING WITH WHICH THE SOLE PLATE IS ASSOCIATED IN SUCH FASHION AS TO FORM WITH A LAST SUPPORTED AGAINST THE TOP OF THE MOLD RIN A BOTTOM-FORMING CAVITY INTO WHICH MAY BE INJECTED A BOTTOM-FORMING COMPOSITION FOR ATTACHMENT TO THE BOTTOM OF AN UPPER ASSEMBLED ON THE LAST, AND MEANS FOR MOVING THE SOLE PLATE RELATIVE TO THE BOTTOM OF THE LAST TO POSITION THE SOLE PLATE FOR INJECTION AND AFTER INJECTION TO APPLY AN INCREASED PRSSURE: SAID MEANS COMPRISING A ROD, MEANS AT ONE END OF THE ROD ADAPTED TO SUPPORT THE SOLE PALTE, A FIRST PISTON LOOSE ON THE ROD OPERABLE TO RAISE THE SOLE PLATE TO A PREDETERMINED POSITION RELATIVE TO THE MOLD RING, AND TO SUSTAIN SAID SOLE PLATE AT SAID PREDETERMINED POSITION UP TO A PREDETERMINED INJECTION PRESSURE, A SECOND PISTON LOOSE ON THE ROD SITUATED BELOW THE FIRST PISTON OPERABLE TO APPLY AN INCREASED PRESSURE TO THE SOLE PLATE AT SAID PREDETERMINED POSITION, AND MEANS FOR SUPPLYING FROM A SINGLE SOURCE OF CONSTANT PRESSURE, PRESSURE FIRST TO THE FIRST PISTON AND THEN TO THE SECOND PISTON.