Abstract: A combination weighing machine for forming a charge of product closely approximating a target amount includes a plurality of weigh scales, each of which receives a quantity of product and produces a signal proportional to the quantity of product received. The quantities are combined according to a combination searching sequence in a search operation, and a combination of scales which closely approximates a target amount is dumped to form the desired charge. The dumped scales are reloaded, and the process is repeated in a cyclic manner. The speed of the cyclic process is improved without significantly sacrificing accuracy by allocating less time than necessary for a complete search of all possible combinations in the search sequence. A search is terminated when the time expires, whether the search sequence is completed or not.

Abstract: A combination weighing machine has a plurality of scales that are periodically dumped and reloaded with products from a bulk container. In each cycle of machine operation, the loaded scales are surveyed, and a combination of the scales which most accurately yields a desired target weight is dumped into a single package. The dumped scales are then reloaded and the process is repeated. Each of the scales has an associated vibratory feeder and accumulator which receives the product from the bulk container and dispenses the product to the scale as needed. In order to feed the scales with loads that provide a large selection of combinations close to the target weight, a control for the vibratory feeders regulates the duration and amplitude of the vibrations in accordance with the loads measured in preceding machine cycles. Also described is a method of dealing with inactive scales by feeding small quantities of articles to the scales requiring reloading until the inactive scales are dumped.

Abstract: A combination weighing machine has a plurality of weigh scales which provide signals representative of the weight of product in each scale. A search control receives the weight signals and selects a combination of the scales which together compose a charge of the product equal to or closely approximating a given target weight. Transient errors existing in the weight signals at high speeds of operation are corrected by means of adjustment parameters that are periodically recalculated on the basis of known differences between settled and unsettled weight signals.