US 7,542,823 B2
Zone controlled conveyor system and a zone controller for use therein
Yoshinori Nagai, Kakogawa (Japan)
Assigned to Itoh Denki Co., Ltd., Hyogo (Japan)
Filed on Aug. 16, 2004, as Appl. No. 10/920,599.
Claims priority of application No. 2003-300249 (JP), filed on Aug. 25, 2003.
Prior Publication US 2005/0065641 A1, Mar. 24, 2005
Int. Cl. G06F 7/00 (2006.01); B65G 43/00 (2006.01); B65G 47/26 (2006.01); B65G 47/31 (2006.01); B65G 13/06 (2006.01)
U.S. Cl. 700—230  [198/460.1; 198/781.05; 198/781.06] 20 Claims
OG exemplary drawing
 
1. A zone controlled conveyor system comprising a plurality of zones for control arranged in a row in the direction of conveyance of articles,
each of the zones having a driving roller for generating power for conveyance, a zone controller for controlling operation of the driving roller in its associated zone, and a presence sensor for outputting a presence signal upon detection of an article,
wherein each of the zone controllers is adapted to receive signals for controlling operation of the driving roller in its associated zone,
wherein each of the zone controllers is also adapted to switch a conveying speed of an article driven by the driving roller in its associated zone among a plurality of maintainable speeds including a prescribed standard, maintained conveying speed, and
wherein the zone controllers are arranged so that while conveyance of any article from a particular zone to a downstream zone is forbidden, the zone controller for the particular zone (a) starts operation of a driving roller in the particular zone at a first maintained conveying speed slower than the standard conveying speed upon transmission of a presence signal of an article to the zone controller from an immediately upstream zone of the particular zone, (b) operates the driving roller in the particular zone at a second maintained conveying speed slower than the first conveying speed after arrival of the article at a predetermined position in the particular zone, and (c) then halts operation of the driving roller in the particular zone when a presence signal is outputted in the particular zone.