Mechanism for feeding cardboard or like blanks

Claim 1

Mechanism for feeding cardboard or like blanks one at a time from the underside of a stack thereof comprising a table, said table comprising a stationary rear part having a planar stack supporting surface and a blank feeding forward part that includes a reciprocatory suction feed cup underlying the stack and adapted on its forward or feeding stroke to pull the leading edge of the lowermost blank in the stack positively downwardly and progress it forwardly beneath a feed gate and carry it into the nip between a pair of feed rollers, a stationary support member underlying said suction cup and having a top planar surface provided with spaced first and second upwardly open recesses connected respectively to a source of suction and atmosphere said suction cup comprising a box having a perforated top surface coplanar with said top surface of the stationary rear part of the table and a flat bottom surface coplanar with said perforated top surface, slidably engaging said top surface of said support member and formed with a downwardly open port, whereby said perforated top surface and said downwardly open port directly enter the same chamber, said box flat bottom surface and said support member top surface being arranged to assure substantially uniplanar reciprocation of said box over an extended period of use regardless of wear, the arrangement being such that on the forward stroke of said box said port communicates with the first recess so that suction is maintained until the blank is taken up by the feed rollers and then the port communicates with the second recess no suction is applied from that point and during at least the initial part of the return stroke.