Abstract: An unflapped envelope (60) is fed, with its crease line trailing, along a path (42) from an envelope feeder and between the rollers of a reversibly driveable roller pair (43), for onward transfer to, for example, an insertion station. When the crease line reaches a predetermined point in front of the roller pair (43), the drive is reversed and the envelope with the crease line leading directed along a flapper path, including a deflecting surface 46; to a flapping chamber or zone (47), at least until the flap (61) is engageable by a flapper blade (44;44a). The drive is then reversed again and the envelope driven back along the flapper path, a flap opening surface (49) of a flapper blade (44) or a pair of flapper blade elements (44a), causing the flap (61) to be stripped from the body of the envelope (60) as it exits the flapping zone, and proceeds to the insertion station.

Abstract: A moistener for applying liquid to an envelope, for use in sealing the latter, comprises a liquid storage tank (70a, 70b) and means, such as wicks (71) for transporting the liquid to the envelope (not shown). The level of liquid in the tank is visible to a user through a window (73). In use of the moistener it is fully inserted into a housing (not shown) but with the window visible to the user. Partial removal of the moistener from the housing permits the tank to be filled with liquid via an opening (76).

Abstract: In order to eliminate complex sheet forming operations, to provide an effective heat sink and to shield against radio frequency interference and electromagnetic induction effects, the housing arrangement has two assemblies which each comprise, inter alia, a die casting made of zinc or other material having equivalent radio frequency interference and electromagnetic induction shielding properties. A main logic circuit board is shielded by the two die castings when they are assembled together.