Kimball’s patent refers to the application of friction to the yarn beam of a power loom. This was accomplished by using a belt, made of steel or iron, which formed nearly a circle around the warp beam. Friction was created by adjusting a screw that caused the circular belt to contract or expand in turn, to increase or decrease the drag on the beam. An elliptical spring eased the movement of the beam within the belt and helped maintain the evenness of the cloth.