Abstract: A bottom sheet storage and feeder apparatus for use with one or more load forming or stacking machines for the purpose of providing one or more bottom sheets for protecting the load. The apparatus chooses a bottom sheet stored in one of a plurality of vertically stacked bins and sequentially moves one or more of the individual bottom sheets longitudinally to a destination location in a plurality of lay down patterns. The machine is constructed with a frame which supports a plurality of vertically spaced storage bins. A lifting assembly, transported by a transfer assembly, includes at least one laterally positioned vacuum member which engages and lifts an individual bottom sheet from one of the storage bins and delivers the selected bottom sheet to a destination location in a selected lay down position. Several lay down patterns may be made by subsequent cycles of the lift and transfer assembly from the storage bins to the destination location.

Abstract: A computer control includes a control member movably mounted for movement in two dimensions wherein orthogonally related gratings are moved to the corresponding directions to generate pairs of quadrature related signals. Circuitry produces binary signals defining four states for each cycle of quadrature signals to change a corresponding count indicating position of the control member. In another variation patterns each having a plurality of spots with a unique combination of gray levels are sensed by a rectangular array of photosensers to determine the position of the movable member.