Patty machine and method of forming patties

Abstract

A patty machine for forming successive patties of a predetermined size from a quantity of a bulk product, such as ground meat. The machine includes a charging chamber in which the product is pressure-fed into a patty mold cavity by means of intermeshing, positive displacement, self-wiping compressor screws. The product is delivered from a feed hopper to the entrance of the charging chamber by means of intermeshing, self-wiping conveyor screws which operate on a demand basis to convey the product to the compressor screws only as needed to thereby avoid unnecessary working or kneading of the product. Shafts for driving and supporting the conveyor and compressor screws extend throughout the length of the machine and each carries one conveyor and one compressor screw. The compressor screws are keyed positively to their respective shafts while only one conveyor screw need be so keyed, the unkeyed conveyor screw or screws being driven through intermeshing relationship with the keyed conveyor screw. By virtue of the self-wiping characteristics of both the conveyor and compressor screws, fat accumulations along the screws, which are often a problem in working with ground meat and similar products, are prevented, thereby avoiding the problem of fatty accumulations breaking off as large clots and being charged into the patty mold.