(57) A rotary feeder feeds sheets or board-like articles (b) to nip rolls (18) in a box-making
machine (6). The articles (b) are successively and individually fed from the bottom
of a stack whose forward edge engages a gate (32) below which the articles are fed
by driven feed members such as wheels (51), rolls or endless belts which engage the
underside of the lowermost article (b). To raise and lower the articles relative to
the surface of the feed members (51), a vertically reciprocable grate (55, 56) is
provided between the drive members (51). The grate (55, 56) and drive members (51)
are mounted in a vacuum box (36) in which a vacuum is created to hold the articles
in proper position on the feed members (51) when the grate (55, 56) is lowered. The
vacuum is also utilized to hold an article with sufficient force to produce the necessary
friction between an article and the feed members (51) for the article to be fed. The
feed members (51) are driven in two opposite directions through an oscillating rocker
shaft (10) and gearing (70, 72, 74). One direction serves to convey an article (6)
below the gate (32) to the nip rolls (18) and the other direction serves to relieve
pressure of an article (b) against the gate (32) prior to conveyance to the nip rolls
(18). The grate (55,56) is actuated through oscillatable shafts (52,52a) connected
to the grate and driven from a cam and cam-follower assembly (90,94) which, in turn,
is driven from a crank gear (16) that is also employed to drive the rocker shaft (10)
through a linkage (12,14) or a quick return slide mechanism (12a,12b,13). A latch
device (122,126) is also provided to releasably hold the grate (55,56) in raised position
above the feed members (51) to interrupt the feeding operation.
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