Apparatus for sensing and measuring tension of tow entering a staple fiber cutter

Claim 1

In an apparatus for cutting elongated, flexible material into predetermined shorter lengths, the apparatus including a horizontally positioned cutter having knives spaced at predetermined intervals around the periphery of the cutter with their edges positioned in vertical planes and facing radially outwardly of the cutter, a driven member movable in a path around the cutter and having a guide mounted thereon for movement therewith for engaging and guiding the elongated material onto and around the cutter for wrapping the material therearound against the knife edges, and wherein the elongated material is guided from above the apparatus to the guide on the movable driven member, the material thus defining a circular path at the location where the material engages the moving guide as the elongated material changes direction and hence generates variable horizontal and constant vertical components of force in engaging the guide at different locations of the moving guide around the cutter prior to being guided by the guide to the cutter, the invention comprising an apparatus for sensing and measuring the tension of the elongated material being wrapped around the cutter by sensing only the vertical components of force and comprising: lever means positioned above the cutter and pivotally mounted about a horizontal axis for rotative movement in a vertical plane; said lever means having at one end spaced from its horizontal axis a guide roll located above and on the axis of the cutter for guiding thereover the elongated material to the guide on the driven member below the lever means, the axis of the guide roll extending horizontally and normally lying substantially in the same horizontal plane as the horizontal axis of the lever means; and means bearing against the lever means to generally maintain the guide roll axis in said substantially same horizontal plane and to sense and measure the vertical force exerted against it due to the forces generated by the elongated material as it moves over the guide roll to the cutter and tends to cause a rotative movement of the lever means.