Abstract: A device for regulating the thickness of gum applied to a paper product comprising means applying gum to said paper product, means for detecting the thickness of the gum being applied to said paper product and producing a control signal which varies with said thickness, and means connected to said detecting means for receiving said control signal and automatically adjusting the amount of said gum being applied to obtain a desired thickness.

Abstract: Independent conveyor belt systems each have a run overlapped with different portions of a run of a single endless belt to clamp an envelope therebetween to convey the envelope through successive sealing material applicator and drying stations. The belt systems enable feeding and removal of the envelopes from the same side of the apparatus and provide for compactness and portability of the apparatus.

Abstract: A plurality of spaced, endless, coplanar, envelope feed belts have their upper runs interleaved and coplanar with the upper run of an envelope support belt at one end of the apparatus, which conveys the envelopes through an apparatus for applying sealant material to the flap closure portion and an adjacent body portion of the envelope. The envelopes are smoothly transferred from the feed belts to the support belt due to the simultaneous support of both belt systems at the delivery end of the apparatus. Another belt is then overlapped with the support belt at the delivery end of the apparatus to clamp the envelopes therebetween as they are conveyed through the sealant applying apparatus.

Abstract: A machine for forming envelopes from blanks comprising a scoring means for receiving said blanks and adding score lines thereto, means for receiving said blanks from said scoring roller and applying glue to selected first locations thereon, means receiving said blanks with applied glue and folding said blanks to cause a seal at said glue locations, means for receiving said folded blanks and inverting said blanks whereby a first portion of said blanks is stationary while said blanks are being inverted, means located at said blank inversion means for forming a desired shape in said stationary portion of said blanks while said blanks are being inverted and means for receiving said formed blanks for gluing and folding said blanks to form completed envelopes.