| 摘要 |
<p>An article feeder for presenting spaced articles or groups of articles to a wrapping machine for wrapping the articles individually or in groups is described. The warpping machine has a continuous drive mechanism driving the film feeding, wrapping, sealing and cut-off units of the machine. The feeder employs a pickup conveyor having longitudinally spaced, retractable pushing dogs for feeding articles in spaced relation to the article receiving conveyor of the wrapper. The pickup conveyor is driven from the drive mechanism of the wrapper. The feeder also includes a metering conveyor for advancing a row of abutting articles toward the pickup conveyor and onto a deadplate between the conveyors. The metering conveyor is intermittently driven by a clutch-brake and driven by a variable speed drive from the wrapping machine drive mechanism but at a slower speed than that of the pickup conveyor. An accumulating conveyor delivers articles from a supply to the metering conveyor so that the articles are in a row in end-to-end abutment on the metering conveyor and the deadplate. Control for the system includes a limit switch operated by a cam driven from the pickup conveyor so that one revolution of the cam represents travel of the pickup conveyor by a distance equal to the spacing between the dogs on that conveyor. A retro-reflective scanner senses an edge of the leading article on the deadplate and cyclical operation of the limit switch, in response to the position of the pickup conveyor dogs, causes the metering conveyor to advance leading articles in the row across the deadplate to be picked up and accelerated by the pickup conveyor. The scanner stops -la-the advance of articles by the metering conveyor when it senses an edge of an article on the deadplate, which is the leading article of the advancing row of articles.</p> |
