The invention relates to an envelope opening mechanism and to mailing apparatus incorporating the mechanism.

Known mailing apparatus provides a variety of possibilities for the treatment of sheet material. Typically, sheet material may be drawn from one or two feeding stations and folded one or more times, or sheets from one station can be inserted within folded sheets drawn from the other station. The sheet or sheets so treated may be -discharged from the apparatus without further treatment, but are usually inserted into envelopes at an inserting station. The envelopes are drawn from an envelope feeding station, and after receiving the sheet material within them, they are closed and sealed prior to discharge from the apparatus.

The envelope feeding station conveniently comprises a hopper or other receptacle for a stack of envelopes from which the envelopes are withdrawn one by one and fed to an opening mechanism. Each envelope consists of a main body portion for receiving the sheet material therein and a flap portion joined to the body portion along a hinge line or edge, and initially overlying the body portion. so that the sheet material can be inverted, the flap portion has to be turned away from the body portion about the hinge edge and it is the function of the opening mechanism to achieve this.

A variety of opening mechanisms are known, as from O93/17880 for example. The present invention is concerned with the provision of an envelope opening mechanism which is of simple construction and which is reliable and convenient in operation.

The invention accordingly provides an envelope opening mechanism in which envelopes are fed in succession from a stack or other supply source into an initial opening station, in which initial opening is effected by bending of the body portion of the envelope, and then withdrawn in the reverse

direction to effect a further opening movement.

The invention also provides an envelope opening mechanism in which a single drive means effects at least two of extraction of an envelope from a stack or other supply source, engagement of the extracted envelope with a static flap opening device, and movement of the envelope away from the opening device towards an inserting station.

The envelopes can thus be successively extracted from a stack with the hinge edge leading by a friction roller into _the opening station or device and withdrawn by the same roller acting on the trailing edge of the envelope at a position angularly spaced around the roller axis from the position of initial engagement with the envelope. The initial engagement may thus be between the roller and the body portion adjacent the hinge edge of the lowermost envelope of a stack of envelopes in a hopper. When the envelope is fully received in the opening station, the roller carries the trailing edge of the envelope opposite the hinge edge around until the edge is caught in the nip between the friction roller and a second roller at the side of the first roller remote from the hopper, so that withdrawal and further opening is effected by passage through the rollers.

The initial opening station can be constituted as a fixed pocket into which the hinge edge of the envelope is fed, the pocket being shaped to cause bending of the envelope body so that the flap portion is separated from it. Conveniently a guide member between friction roller and the pocket assists correct placing of the envelope in the opening pocket and functions to assist the opening movement during envelope withdrawal from the pocket.

The opening mechanism of the invention can thus employ only a single driven part, typically a friction roller as described above, for extraction of the envelope from the hopper for opening, and for feeding the opened envelope to

the inserting station and for withdrawing it therefrom.

The invention is further described below, by way of example , with reference to the accompanying drawings , in which:

Figure 1 is a part schematic side view of a mechanism in accordanc e with the invent ion f or removing enve lope s successively from a hopper and opening the envelopes , and

Figure 2 is a like view of the mechanism of Figure 1 , t t showing a dif f erent phase of the envelope opening -operation.

The envelope opening mechanism illustrated is included in a mailing apparatus in which sheet material is inserted at an ins erting station into an envelope opened by the mechanism.

The illustrated opening mechanism is thus located in a flowpath for envelopes 10 between a hopper 1 for receiving a stack of the envelopes and a downstream insert station ( not shown ) . Apart from the envelope opening mechanisms , the mailing apparatus may be conventional and will not be further described.

The hopper 1 comprises a floor 2 sloping downwardly in a feed direction and upstanding front and rear walls 4 & 5 . Each envelope 10 comprises a body portion 11 with a flap portion 12 overlying it , the flap and body portions being joined at a hinge line . The envelopes 10 are stacked within the hopper 1 with the flap portions 12 uppermost , and with the hinge edges towards the corner between the floor 2 and the rear wall 5.

A friction roller 20 below the hopper 1 extends up into the hopper through a gap between the floor 2 and the rear wall 5 so as to engage the body portion of the lowermost envelope 10 at its leading end, that is , adjacent the hinge line . Rotation of the friction roller 20 in the direction indicated by arrow 21 leads the lowermost envelope outwardly

of the hopper 1 beneath an inclined portion of the rear wall 5, and in engagement with a stationary guide roller 6. The guide roller 6 does not normally rotate, but can be rotated from time to time when a flat has been worn by the passage of the envelopes, so as to replace the flat by a curved portion of the roller edge.

The front wall 4 includes an inwardly protruding shelf 7 which provides support for all but the lowermost of the stack of envelopes to relieve the weight of the envelope stack on -the roller 20.

The extracted envelope is thus moved through a gap 22 between a first or upstream floor plate 24 of the opening mechanism and a guide member 25 located above it. The guide member 25 comprises a rear plate 26 extending upwardly generally perpendicular to the floor plate 24 and a shorter wall 27 extending from the lower edge of the rear plate and inclined to it towards the hopper 1.

The edge at which the two walls 26 & 27 join defines with the floor plate 24 the gap 22 through which the envelope 10 moves to an opener pocket 30. The pocket 30 is formed by an end portion 31 of the floor plate 24, inclined downwardly in the direction in which the envelope moves, and an end plate 32 extending upwardly from the free end of the end portion 31 and then rearwardly, back towards the hopper. On entry into the pocket 30, the hinge edge of the envelope 10 engages the end plate 32 and is fed downwardly into the pocket over the edge between the floor plate 24 and its end portion 31, whereby the envelope is bent over this edge so as to cause the flap portion 12 to lift up from the body portion 10 as shown in Figure 1.

From this position, the trailing edge of the envelope 10, the edge remote from the hinge edge is carried by the friction roller 20 downwardly so as to overlie the floor plate 24. This is the position shown in Figure 2. Continued

rotation of the friction roller 20 in the same direction moves the trailing edge into a nip formed between the roller and a co-operating roller 35 received through a slot in the floor plate 24. The rollers 20 & 35 can be jointly driven, as by a geared connection.

The envelope 10 now moves between the rollers 20 & 25 in the reverse direction, away from the pocket 35, over the floor plate 24. The inner side of the flap portion 12 engages the upright wall 26 of the guide member 25 as it -passes through the gap 22 and is consequently subjected to a further opening movement. The opened configuration of the body and flap portions 11 & 12 is further ensured by the action of the rollers 20 & 35 as the envelope 10 passes between them.

Opening has thus been effected, but the illustrated mechanism includes two further sets of drive rollers between which the opened envelope is fed to the inserting station. These are the sets of rollers 37 at the downstream end of the floor plate 24 and the roller set 39 further downstream. The lower roller of each of these sets protrudes through a respective slot in a second or downstream floor plate 40 of which the upper surface is generally aligned with that of the floor plate 24. The diameters of the rollers 37 & 39 are such as to slightly accelerate the envelopes received from the rollers 20 & 25, to separate each envelope slightly from the succeeding envelope.

The floor plate 24, the end wall 32 and the guide member 25, are adjustably mounted within the mechanism to accommodate envelopes of different sizes. These components can thus be moved together in the directions of the arrow 41 at the beginning of a run, to a position appropriate to the size of envelope being handled.

The opened envelope needs to be held stationary at the inserting station for insertion of the sheet material and the

drive to the feed rollers of the opening mechanism is interrupted accordingly under control of sensor means sensing arrival of an envelope at the inserting station. The drive, control and timing arrangements of the mailing apparatus are generally conventional and are not therefore further described.

The invention can of course be embodied in a variety of ways other than as specifically described and illustrated.