Suction device for picking up sheets

Claim 1

A suction device for picking up sheets of papers and the like individually from the top of a pile of sheets for feeding to a copying machine or the like comprising: a suction manifold movable through a path toward and away from the sheet to be picked up, means creating a suction on said suction manifold commencing at a predetermined point in the said path of said manifold toward the sheet to be picked up, and a plurality of spaced tubular suction members carried by said suction manifold, each of said suction members comprising: a suction mouth at the extremity of one end of said suction member and in alignment with the other said suction mouths so that the said suction mouths together contact the sheet to be picked up, passage means connecting the other end of said suction member to said suction manifold, an annular seat in the interior of said suction member, a movable ball in the interior of said suction member, said ball being positioned between said mouth and said annular seat and having a diameter greater than the diameter of said annular seat and less than the interior diameter of said suction member, said ball being movable between a first position spaced a first distance from said annular seat, a second position spaced a lesser distance from said annular seat, and a third position wherein said ball engages and closes said annular seat; the distance between said first position and said second position being equal to the distance said ball travels under the influence of the suction created in said suction manifold between the moment that suction commences in said suction manifold as said suction manifold moves toward the sheet to be picked up and the moment the sheet to be picked up would normally be contacted by said mouth, and the distance between said second position and said third position is a predetermined very small distance, whereby upon the application of suction to said suction member as said suction manifold moves toward said sheet to be picked up said ball begins to move from said first position toward said second position under the influence of said suction, and said ball arrives at said second position at the moment said suction mouth contacts said sheet to be picked up, but if said suction does not contact a sheet to be picked up, said ball continues through said second position to said third position, thus immediately closing said annular seat, and halting the communication of suction to said suction member, and a ball stop extending into the interior of said suction member at a point between said ball and said mouth and engagable with said ball to define said first position.