1. Spreader conveyor apparatus of the type comprising an endless spreader conveyor belt, a discharge conveyor running laterally beneath the delivery end of said spreader conveyor belt, article supply means for depositing articles on the upper reach of said spreader conveyor, and drive means for advancing and retracting the delivery end of said spreader conveyor belt across the discharge conveyor; the improvement comprising laterally spaced tracks extending laterally of said discharge conveyor, a fixed length, shiftable spreader conveyor frame, means mounting said spreader conveyor frame for reciprocation in said tracks, means mounting said spreader conveyor belt for travel around said frame, said spreader conveyor drive means comprising means for continuously driving the upper reach of said spreader conveyor belt in the advance direction, reversible means for driving the lower reach of said spreader conveyor belt, means for operating said reversible drive means in the same direction and at substantially the same speed as said continuous drive means for advancing both reaches of said spreader conveyor belt and the frame across said discharge conveyor while said spreader conveyor is receiving a row of articles, and means for operating said reversible drive means in the opposite direction and at a speed higher than that of said continuous drive means for quickly retracting both the spreader conveyor frame and the delivery end of the belt to deposit a row of articles from the spreader conveyor to the discharge conveyor while said continuous drive means advances the upper reach of said spreader conveyor belt relative to the frame for receiving articles from said supply means.

3. Spreader conveyor apparatus of the type comprising an endless spreader conveyor belt, a discharge conveyor running laterally beneath the delivery end of said spreader conveyor belt, article supply means for depositing articles on the upper reach of said spreader conveyor belt, and drive means for advancing and retracting the delivery end of said spreader conveyor belt across said discharge conveyor; the improvement comprising laterally spaced tracks extending laterally of said discharge conveyor, a fixed length spreader conveyor frame shiftable in said tracks, means mounting said spreader conveyor belt for travel around said frame, said spreader conveyor drive means comprising a sprocket for engaging and advancing the upper reach of said spreader conveyor belt, means for driving said belt advancing sprocket continuously the belt advancing direction, a reversible sprocket engaging the lower reach of said spreader conveyor belt, means for driving said reversible sprocket in the opposite direction and at substantially the same speed as said belt advancing sprocket for advancing both reaches of said spreader conveyor belt and the frame across said discharge conveyor while receiving a row of patties, and means for driving said reversible sprocket in the opposite direction and at a speed higher than that of said belt advancing sprocket for quickly retracting both the spreader conveyor frame and the delivery end of the belt for depositing a row of patties in said discharge conveyor and while said belt advancing sprocket continues to advance the upper reach of said spreader conveyor belt relative to the frame for receiving articles from said supply means.

7. Spreader conveyor apparatus for a patty machine wherein said patty machine has a continuously rotating shaft that makes one revolution for each patty delivered by the machine, and an endless chain spreader conveyor belt for receiving patties from the patty machine and distributing them along a laterally running discharge conveyor; the improvement wherein said spreader conveyor belt runs freely around a fixed length, longitudinally shiftable frame, means for driving the upper reach of said spreader conveyor belt continuously from said patty machine shaft in the belt advancing direction and at a relatively low speed, advance clutch anD drive means for driving the lower reach of said spreader conveyor belt from said patty machine shaft in the same direction as said upper reach is driven and at said relatively slow speed when said advance clutch means is engaged to thereby advance said frame and both conveyor belt reaches as a unit, retract clutch and drive means for driving the lower reach of said spreader conveyor belt in the opposite direction and at a relatively high speed when said retract clutch means is engaged and when said advance clutch means is disengaged for retracting the spreader conveyor frame and the delivery end of the belt at a relatively high speed while the upper reach of the belt continues to be driven in said advance direction relative to the frame at said relatively low speed from the patty machine shaft, and control means for engaging said advance clutch means and disengaging said retract clutch means when said conveyor frame is retracted and for disengaging said advance clutch means and engaging said retract clutch means when said conveyor frame is advanced.

9. In a spreader conveyor of the type wherein the upper reach of the spreader conveyor belt receives soft articles such as meat patties from a forming machine, drive means for advancing and retracting the delivery end of the belt across a discharge conveyor for dropping rows of patties thereon and control means for said spreader conveyor drive means; the improvement wherein said spreader conveyor belt is trained around a fixed length frame, means for reciprocating the entire belt and the frame for advancing and retracting the delivery end of the belt, a light weight patty sensor positioned to be lifted by a patty at the delivery end of said spreader conveyor belt, a trip plate member that is dropped by lifting of said sensor, electric control means operated by the dropping of said trip plate member for retracting said frame and hence the delivery end of said spreader conveyor belt, and electro-mechanical control means for thereafter advancing said frame and hence the delivery end of said spreader conveyor belt, said electro-mechanical control means for advancing the spreader conveyor comprising a cocking member positioned to be operated by the conveyor upon retraction, and a mechanical connection between said cocking member and said trip plate member for cocking the trip plate member upon retraction of the conveyor.