Measuring tape

Claim 1

A TAPE DEVICE, COMPRISING A FLAT, GENERALLY RECTANGULAR HOUSING AN OUTLET AT ONE END, A FLEXIBLE TAPE COILED INTO A ROLL IN SAID HOUSING AND WITHDRAWABLE THROUGH SAID OUTLET FOR MAKING MEASUREMENTS OF LENGTH, SAID TAPE HAVING A LINEAR SCALE ON ONE SIDE THEREOF, A TRANSPARENT WINDOW IN SAID HOUSING FOR VIEWING SAID SCALE ON AN OUTERMOST COIL OF SAID ROLL, A REFERENCE MARK ADJACENT SAID WINDOW WHEREBY THE DISTANCE BETWEEN THE FREE END OF THE WITHDRAWN TAPE AND THE OTHER END OF THE HOUSING IS INDICATED BY SAID SCALE AT SAID WINDOW, ANOTHER MARK ON THE OTHER SIDE OF SAID TAPE FOR DIRECT READING OF OUTSIDE MEASUREMENTS MADE WITH SAID TAPE, AND GUIDE MEANS IN SAID HOUSING SO THAT THE CIRCUMFERENTIAL LENGTH OF SAID OUTERMOST COIL BETWEEN SAID ONE END OF THE HOUSING AND THE REFERENCE MARK ADJACENT SAID WINDOW IS MAINTAINED CONSTANT AS THE TAPE IS WITHDRAWN FROM THE HOUSING, SAID GUIDE MEANS COMPRISING A FIRST ARCUATE ROW OF CONVEX ROLLER BEARING INSIDE THE HOUSING, AND A SECOND ARCUATE ROW OF CONCAVE ROLLER BEARINGS CONCENTRIC WITH AND SPACED FROM THE FIRST ROW, THE BEARING BEING IN OPPOSED RELATION, TO DEFINE A NARROW ARCUATE PASSAGE THEREBETWEEN, SAID PASSAGE BEING CURVED IN CROSS SECTION, THE CURVATURE OF THE COILS OF THE ROLL CORRESPONDING TO THAT OF SAID PASSAGE, WHEREBY THE OUTERMOST COIL OF THE ROLL IS MOVABLY GUIDED IN SAID PASSAGE BETWEEN THE ROLLER BEARINGS.