Abstract: Retrofittable hay bale measuring apparatus measures the size of the hay bale being formed, and indicates the size of the bale being formed to a control and display unit. The baler operator sets the desired hay bale size and monitors the baler operation on the display. A contact wheel, which contacts the hay bale and rotates as the bale is being formed, is rotationally attached to a measuring wheel. Alternatively, the contact wheel may itself comprise the measuring wheel. The rotation of the measuring wheel is monitored by a rotation detector which generates a hay bale measuring signal, and sends it to the control and display unit. The control and display unit generates a signal which indicates to the baler when it is time to tie off a bale of hay, based upon the measuring signal.

Abstract: Hay bale measuring apparatus utilizes two measuring wheels for measuring the string used by the baler, and indicating the amount of string to a control and display unit. The baler operator sets the desired hay bale size and monitors the baler operation on the display. The control and display unit generates a signal which indicates to the baler when it is time to tie off a bale of hay. The measuring wheel includes a plurality of teeth and is used with an optical beam generator and optical beam detector. String is wrapped once around the wheel and turns the wheel as it is pulled by the baler. As the wheel turns, the teeth interrupt the beam from the beam generator, forming a series of bursts of light. The beam detector generates a burst of current coincident with each burst of light, and sends it to the control and display unit.