Sheet deliverer for rotary printing machines

Claim 1

A sheet deliverer adapted for sequentially transporting sheets having printed portions at least on the undersides thereof and print-free margins defining said printed portions from a rotary printing machine to means defining a product collection site, said sheet deliverer comprising in combination: continuous means for sequentially transporting said printed sheets from said rotary printing machine to said product collection means thereby defining a path of conveyance of said sheets therebetween, said transporting means including gripping means for gripping the leading edge portion of said printed sheets as each of said printed sheets leaves said rotary printing machine and for releasing said printed sheets over said product collection means, said transporting means having at least one section extending substantially horizontally over said product collection means; plate means disposed below said transporting means thereby defining a space through which said printed sheets are conveyed, said plate means having a downstream end portion terminating upstream of said product collection means and being transversely oriented relative to said path of conveyance, wherein an air cushion is developed between the underside of said sheets and said plate means upon the conveyance of said sheets by said transporting means, said air cushion at least partially supporting said sheets above said plate means; a plurality of elongated guide yoke means defining a conduit through which blown air can pass, said guide yoke means being disposed along said downstream end portion substantially equally spaced relative to each other therealong, each of said guide yoke means being oriented in a direction opposite to said path of conveyance so that said blown air is directed opposite to the direction of said path of conveyance; adjustment means for transversely adjusting said guide yoke means so that said guide yoke means only contacts said printed sheets along the print-free margins thereof; and a plurality of braking means downstream of said guide yoke means, each of said guide yoke means being paired with a predetermined one of said braking means, said braking means for contacting said printed sheets at the print-free margins thereof and for reducing the velocity of conveyance of said printed sheets so that upon release of said leading edge portion by said gripping means, said printed sheets will be deposited into said product collection means; said guide yoke means, by virtue of said blown air, for (a) creating a partial vacuum along said downstream end portion of said plate means to cause said sheets to be drawn against said guide yoke means to thereby cause a trailing edge of said sheet to contact said braking means and (b) supplementing said developed air cushion to support said sheets above said plate means to prevent contact between said conveyed sheets and said plate means.