Apparatus for measuring foot length

Claim 1

A FOOT MEASURING APPARATUS COMPRISING: A STATIONARY FRAME; A FOOT SUPPORT ON SAID FRAME; HEEL AND TOE ABUTMENTS EACH EXTENDING ACROSS THE WIDTH OF SAID FOOT SUPPORT AND BEING INDIVIDUALLY MOUNTED FOR TRANSLATION MOTION ALONG THE LENGTH OF SAID FOOT SUPPORT; BIASING MEANS MOUNTED ON SAID FOOT SUPPORT OPERATIVELY CONNECTED TO SAID HEEL AND TOE ABUTMENTS ADAPTED TO URGE SAID ABUTMENTS APART; MOTION LIMITING MEANS ON SAID FOOT SUPPORT INTERPOSED IN THE OUTWARD PATH OF EACH ABUTMENT ADAPTED TO LIMIT ITS MOVEMENT IN RESPONSE TO SAID SPRING MEANS DIFFERENTIAL PULLEY MEANS ON SAID FOOT SUPPORT ADAPTED TO MOVE SAID HEEL AND TOE ABUTMENTS, SAID DIFFERENTIAL PULLY MEANS COMPRISING A FLEXIBLE MEMBER, IDLER PULLEY MEANS ROTATABLY JOURNALLED ON ONE END OF SAID FOOT SUPPORT, A DIFFERENTIAL BLOCK, SAID FLEXIBLE MEMBER BEING FIXED AT ONE END TO A FIRST ONE OF SAID HEEL AND TOE ABUTMENTS AND BEING ENTRAINED IN ORDER ABOUT SAID IDLER PULLEY MEANS AND SAID DIFFERENTIAL BLOCK, AND HAVING ITS REMAINING END FIXED TO THE SECOND ONE OF SAID HEEL AND TOE ABUTMENTS, FLEXIBLE MEANS CONNECTED TO ONE END OF SAID BLOCK AND CONNECTED AT ITS REMAINING END TO AN ACTUATING MEANS ADAPTED TO PULL SAID FLEXIBLE MEANS SO AS TO BRING SAID HEEL AND TOE ABUTMENTS TOWARDS EACH OTHER.