This invention relates to apparatus for closing an envelope .

In automatic mailing machines there is a need for a reliable apparatus for closing envelope flaps after the envelopes have been filled A difficulty m this respect is that the apparatus may be required to close envelopes of different sizes, wherein the distance from the flap to the opposite edge of the envelope varies.

Accordingly, the present invention provides an apparatus for closing an envelope comprising first transport means for gripping an envelope and transporting it towards an abutment member, m which tne abutment member is biased towards the first transport means and is arranged to be movable away from the first transport means against the bias oy means of abutment with an envelope being transported by first transport means, unless the crease of the envelope flap lies between the transport means and the abutment means, and second transport means for transporting a folded envelope away from the abutment means, the second transport means being arranged to apply pressure to the folded flap of the envelope

Thus the apparatus can accomodate envelopes of different sizes without the need for adjustment

The invention also provides a method of closing an envelope comprises feeding the envelope towards an aoutment member n a direction with tne edge of the envelope opposite to tne flap first, the aoutmer.t member oeir.g Diase towards tne envelope such tnat t s movaole against tne bias by the envelope unless the crease of the envelope flap lies between tne eeding means and the aoutment means, such that the

envelope folds at the crease; feeding the folded envelope away from the abutment means; and applying pressure to the folded envelope .

In a preferred embodiment, the first and second transport means each comprise a pair of rollers. For example, the first transport means comprises first and second rollers, and the second transport means comprises the second and a third roller. In this case, the second roller may have a textured surface, for providing fictional adherence with the folded crease of the envelope.

The abutment means is conveniently mounted in a channel for receiving the envelope. For example, the abutment means may comprise the free end of a leaf spring projecting into the channel . The abutment means may be mounted above the first transport means, in which case the abutment means may comprise a slidably mounted weight.

In order that the invention may be more readily understood, reference will now be made, by way of example, to the accompanying schematic drawings, m which:

Figure 1 is cross-sectional side view of an apparatus according to one embodiment of the invention;

Figures 2a to 2d are cross-sectional side views of an apparatus according to another embodiment of the invention.

Referring to Figure 1, the apparatus has a housing 2 including an entrance region 4 for open envelopes, and an exit region 6 for closed envelopes . The entrance region 4 includes a support surface 12 for supporting envelopes for introduction into the apparatus, for example by means of a pair of feed rollers. Such a pair of feed rollers may for example be one of a plurality of such pairs mounted adjacent the support surface 12, for example for transporting envelopes from a filling station where the contents are inserted.

First transport means comprises first and second nip rollers 16, 13, for transporting an envelope 14 towards an aoutment memoer 24 m tne form of the free end of a leaf spring 2Ξ The leaf spring 25 is conveniently mounted on tne housing 2 above the first ano second nip rollers 16, 18, such that the distance between the first and second nip rollers 16, 13 and the free end 24 of the spring 25 is smaller than tne depth of the smallest envelope with which the apparatus is intended to oe used, where the depth is the distance from the crease of the envelope flap to the opposite edge of the envelope A cnannel 22, including a baffle 20 is provided to guide the envelope 14, from the first and second rollers 16, 18 to the end of the leaf spring 25 The leaf spring 25 is arranged to provide a biasing force towards the first and second rollers 16, 18 which can be overcome by an envelope 14 being transported thereby, such that the end 24 of the leaf spring 25 is movable against the bias. However the biasing force is such that, if an envelope crease 26 lies between the first and second rollers 16, 18 and the end of the leaf spring 25, the envelope is no longer sufficiently rigid to overcome the bias, and the envelope 14 folds at the crease 26 as the flap 28 is fed out of the first and second nip rollers 16, 18.

A third nip roller 30 is provided to cooperate witn the second nip roller 18 to form second transport means for transporting the folded envelope out of the apparatus tnrough tne exit region 6 When the end of the flap 28 nas left the first and second nip rollers 16, 18, the envelope no .onger provides a force against tne b as of the leaf spring 25 ^hich therefore urges the envelope downwardly towards the second and tmrd nip rollers 18, 30, again guided by the baffle 23 It can be seen that transporting envelopes into and out of the aoDaratus can be effected bv rotatinσ tne second roller

,„., _Λ« 6/26075

continuously m the same direction. The second nip roller 18 may have a rubberised outer surface 13 to encourage fictional adherence with tne envelope crease 26, to carry it from the mo witn the first roller 16 to the nip with the third roller 30 The n p of the second and third nip rollers 18, 30 also serves to apply pressure to the folded flap of the envelope, for example to seal the envelope.

Figures 2a to 2d illustrate the process of closing the envelope, according to a modified version of the apparatus according to the invention. In this embodiment, the abutment member 32 is a weight slidably mounted in a channel 34. The weight 32 rests at a distance from the nip 37 between first and second rollers 36, 38 which is smaller than the depth of the smallest envelope with which the apparatus is to be used.

In Figure 2a, the first and second rollers 36, 38, which constitute first transport means, drive an envelope 42 into the apparatus. In Figure 2b the envelope 42 is deflected by the far wall 44 of the channel to abut the weight 32, and slide it up the channel. In Figure 2c, the envelope crease 46 has left the nip 37 of the first and second rollers 36, 38 and the envelope folds at the crease 46 under tne downward force of the weight 32. The folded crease of the envelope 42 is then guided by the second roller 38 into a second nip between the second and third rollers 48 The envelope is transported out of the apparatus tnereby, and also pressed to seal the flap 40, as z e weight 32 returns to its rest position