US Patent 7373891 Quilting method and apparatus using frame with motion detector

A frame is provided for mounting a fabric layer stack and retaining it in a substantially taut condition. The frame is supported for manually guided movement beneath a fixedly located stitch head and a detector is provided to produce signals representing the magnitude of frame translation, and thus the magnitude of stack translation. The detector signals are applied to control circuitry to actuate the stitch head at a rate related to stack translation speed. The frame is supported by bearings; wheels, slides, etc, which permit the frame to be freely manually guided across a frame supporting surface beneath the stitch head.