EP0198467B1 - Moistening device for envelope flaps - Google Patents

Description

The present invention relates to devices for wetting the closure flaps of envelopes, intended to be used in particular in automatic mail processing installations and more specifically in franking machines to which they can be attached.

The application of humidity, in particular, to the gummed region of the flap of the envelopes, for their closing must be carried out in a safe and rapid manner, independently of the types and formats of envelopes concerned. Advantageously, this wetting operation is carried out during the transfer of the envelopes from the output of a destacker ensuring the separation of the envelopes whose flaps are open at the entrance to a franking machine. In addition to the safety and speed objectives of the wetting devices, they must, in addition, leave on the envelope flaps sufficient humidity for their closure but not excessive to avoid the flow of droplets or burrs when they are closed.

Several devices ensuring the wetting of the envelope flaps are already known. They comprise a reservoir of moistening liquid, in particular water, and a moistening member which extends or immerses more or less in the liquid reservoir and which is licked by the flap of each of the envelopes. This wetting of the flaps takes place during the flat entrainment of the envelopes above the wetting device, on a movement mechanism or plane on one of the edges of which the flaps of the envelopes fall freely. In line with the wetting member, a spring-type flap, or the like, applies the flap of each of the envelopes against this wetting member for transferring moisture onto the flaps.

Document FR-A-2 332 813 describes an embodiment of such a device for wetting envelope flaps. In this device, the humecting member is constituted by an endless belt driven to transfer the humectant liquid from the liquid reservoir to the flap of the envelopes, during its passage near the belt against which it is applied over the entire length. of its gummed part.

Document FR-A-2 195 532 describes another embodiment of such a wetting device in which the wetting member consists of a wick held by a wick support arm, which has one of its ends dipping in the liquid from the reservoir and the other end forming an elongated portion of wetting released from the support arm. In this embodiment, the transfer of moisture along the wick is ensured by capillarity in the material which forms this wick and the flap is moistened by friction against the terminal wetting portion of the wick. In this device, the transfer of moisture from the terminal wetting portion of the wick to the gummed flaps is difficult to regulate. Indeed, this transfer depends on the force of application of the flaps against the wetting portion of the wick; this application force is itself a function of the thickness of the envelope flaps and may then be insufficient to ensure proper wetting of the flaps of thin envelopes or, on the contrary, be excessive for flaps of thick envelopes and coming in the latter case cause possible damage to these envelopes whose flaps are braked.

This friction also results in a transfer of rubber from the flaps to the wetting portion of the wick, which is detrimental to the regularity of the transfer of moisture to the flaps, over time. This moisture transfer to the envelope flaps also depends on the moisture transfer in the wick itself, which, obtained by the capillary effect of the wick material, is sensitive, in particular, to the lime water commonly used as a humectant. In addition, in the device according to this embodiment, the humidity transferred to the flaps varies over the length of these flaps; it may become insufficient on the end part of the flaps of the long envelopes which lastly lick the wick or be on the contrary excessive on the front end of these flaps.

Document US-A-2,113,738 describes another device for wetting envelope flaps during the envelope drive. In this device, the envelopes are driven in a vertical position, they arrive in the device with their flap at the bottom, which is initially folded but not sealed on the envelope body, and which is unfolded horizontally for their wetting, by an opening element. The wetting device proper comprises a wetting roller, conical in shape, mounted at the end of a substantially horizontal feed tube, and an associated pressing element, extending inclined according to a generator of the roller below this roller. After wetting, the flap is folded over to be sealed by a pair of pressure rollers.

In this device, the tapered roller rotates with the advance of the flap against it. It has radial channels opening on the one hand into circular imprints segmented from its periphery and on the other hand on radial orifices of the supply tube, for a distribution of water on its periphery when it rotates. The supply tube is connected to a remote source and fitted with a valve.

In this known device, the flaps are in contact with pressure against the roller which it drives for the distribution of water on its periphery. This pressure contact is of delicate adjustment to avoid any damage to the envelopes and allow sufficient but not excessive distribution of water around its periphery.

The object of the present invention is to produce a device for uniform wetting of the flaps whatever the speed of travel of the envelopes and their length, this practically without risk of damage to the envelopes and without modification of the transfer of humectant liquid over time.

The subject of the present invention is a device wetting of envelopes closing flaps during their displacement in the direction of their length along a substantially horizontal trajectory, comprising a rotary wetting roller, said brush, and an associated deflector flap, for receiving between them the flaps of the successive envelopes, and a means for supplying humectant liquid to said brush from a remote liquid reservoir, characterized in that said brush has its substantially vertical axis and is mounted with said deflector flap under the path on which the envelopes run flat with their flap falling substantially vertically, and in that said brush consists of an alternating stack of foam rings and rigid rings on its axis, with the foam rings protruding on the periphery of the rigid rings having between them a plurality of circular grooves over the height of the brush and that said deflector flap comprises a plural ity of ribs partially engaging in the respective grooves of the brush in a wetting area, to ensure, without contact with the flap on said brush, the pressure application of the flaps against the foam rings of the brush and their moistening.

According to a particular feature of the device, said brush is driven at a peripheral speed substantially equal to the speed of the envelopes.

According to another particular feature of the device, said supply means is coupled to said brush, in a so-called brush supply zone, situated substantially opposite the deflector flap and at the top of said brush on its vertical axis. , and a distributor of the associated liquid is pressurized against the brush over its height, between the supply zone and the wetting zone.

According to another particular feature, said brush is supplied by a peristaltic pump, said pump advantageously being driven with the brush by the same motor.

• - la figure 1 est une vue de dessus schématique du dispositif de mouillage selon l'invention,
• - la figure 2 est une vue à échelle agrandie de l'une des parties du dispositif,
• - la figure 3 est une vue en coupe partielle du dispositif, selon la ligne brisée III-III de la figure 1,
• - la figure 4 est une vue en coupe partielle de l'un des éléments du dispositif.

The characteristics and advantages of the invention will appear more clearly during the description given with regard to an embodiment illustrated by way of example in the accompanying drawings. In these drawings:

• FIG. 1 is a schematic top view of the wetting device according to the invention,
• FIG. 2 is an enlarged view of one of the parts of the device,
• FIG. 3 is a partial sectional view of the device, along the broken line III-III of FIG. 1,
• - Figure 4 is a partial sectional view of one of the elements of the device.

With reference to FIG. 1, it can be seen that the wetting device according to the invention comprises a rotating vertical brush 1, a deflector 2 facing the brush, a reservoir 3 of moistening liquid, in particular water, distant from the brush, and a peristallic pump 4 ensuring from the reservoir the regulated supply of water to the brush. A water bottle 30 ensures the maintenance of water in the reservoir 3.

This device is mounted under the substantially horizontal plane of travel of the body of the envelopes driven in the direction of their length on a plate 5, according to arrow 50. It receives, between the brush 1 and the deflector 2, their flaps whose plane is indicated by the dashes 6 and ensures the transfer of water to the gummed side of the flaps. This water transfer takes place from a vertical zone known as wetting, 10, of the brush against which the flaps are pressed by the deflector, during the scrolling of the envelopes. This wetting zone 10 corresponds to an end part of the deflector, which comes to overlap partly in the brush, as will be seen below in particular with reference to FIGS. 3 and 4.

The brush 1 is supplied with water by the peristallic pump 4 with a tube 40 for withdrawing water from the reservoir 3 and distributing water on the brush 1. This tube is flexible, it has its fixed intermediate portion at the inlet and outlet of the pump 4 on a fixed support 41 and mounted in an open loop on a horizontal plate 42, forming the rotor of the pump, at the periphery of vertical rollers 43 carried freely in rotation on the rotor. These rollers are likely for some of them to come simultaneously to exert a sufficiently strong pressure on the intermediate portion of the tube 40 to compress it and plug its inner channel. The successive rollers 43 thereby compressing the tube define between them on the tube quasi-independent sections. By the rotation of the rotor indicated by arrow 44, each section of tube before its obturation draws water from the reservoir; when it is closed, it displaces the volume of water withdrawn; when it opens, it delivers this volume of water to the brush. This volume of water withdrawn and distributed is thus dosed to the desired value.

As can be seen in FIG. 1, but more particularly in FIG. 2, to which reference is essentially made, the end of water distribution from the tube 40 to the brush 1 opens onto the peripheral part of the brush, called the feed 11, substantially opposite to the wetting area 10. It is fixed to a housing 7 of the brush, open on the wetting area 10 and the parts directly adjacent to this wetting area so as not to impede the passage of the flaps envelopes. This housing defines a semi-cylindrical housing for the brush. It forms at its upper part, at the level of the upper end of the brush, an access pipe 71, projecting on its external face and on which the water distribution end of the tube 40 is fitted.

Downstream of this pipe 71, the downstream being defined opposite the direction of rotation of the brush indicated by the arrow 12, the casing 7 defines a second housing 72 for a water distributor cylinder 73 over the height of the brush. This cylinder 73 is mounted on a vertical axis 74. It is applied in pressure on the periphery of the brush and is urged for this purpose, in an elastic manner by a spring blade 75 for returning the axis 74 towards the brush 1. This cylinder is free to rotate on its axis, the pressure it exercises in the brush ensures sufficient distribution of water over the entire height of the brush.

The casing 7 has two flanges at its upper and lower ends, both identified with the reference 76, the upper flange being the only visible in FIG. 1 and the lower one the only visible in FIG. 2. The lower puddle 76 constitutes a sole of holding the casing 7 on a bottom plate 8 supporting the device. It also makes it possible, with the upper flange which is analogous thereto, to maintain the distributor cylinder 73.

As shown in Figure 1 but more visible in Figure 3, the bottom plate 8 is profiled to define under the brush 1 and the housing 7 a gutter 80 collecting the water likely to flow in particular from its area d and the water distribution area on its height. This gutter 80 is sloping inclined towards the tank 3, formed directly in the bottom plate, and opens into the tank.

With reference to FIG. 3, it can be seen that this same bottom plate 8 also has, in relief on the bottom of the gutter 80, a first boss 81 which the axis 13 of the brush crosses and a second boss 82 which a motor axis 9. This motor axis 9 is coupled to the brush 1 for its rotational drive by two toothed pinions 90 and 14 carried by the axis 9 and the brush 1 and engaging one with the other under the flange lower 76 of the casing 7. Advantageously, the brush is driven at a peripheral speed substantially equal to the speed of travel of the envelopes, so as to avoid friction and distortion of the envelopes.

Although not shown in the figures, the pump can be driven from the same motor axis 9, which will be coupled to the axis of the rotor by suitable gears.

The brush 1 is described below with reference essentially to Figures 3 and 4; the deflector associated with it is described with reference to these same figures but also to the preceding figures.

The brush 1 comprises a hub 15, a stack of plastic rings 16 formed on the hub and a plurality of foam rings 17 kept offset from one another between the preceding rings 16 acting as spacers. The hub 15 carries at one of its ends the pinion 14. It has in the vicinity of this end a shoulder 18 retaining, with an offset relative to the pinion 14, the stack of plastic rings. At its opposite end, a button 19 ensures, using a screw 19 ', mounted in an axial passage presented by the button and screwed into an axial threaded hole of the hub, the blocking of the stack which it carries .

The plastic rings 16 have two shoulders on one side and the other, against which the foam rings 17 are held, each against the shoulders of two successive plastic rings. These foam rings 17 have their periphery in relief on the periphery of the intermediate portions of the plastic rings, forming spacers between foam rings; they thus define between them a series of grooves 20 on the height of the brush.

The deflector 2 consists of a plate advantageously made of plastic, extending substantially over the height of the brush. It has on its face opposite the brush, a set of ribs 21 partially engaging in the grooves 20 between the foam rings of the brush, in the wetting area of the brush. These ribs 21 thus engaged in the grooves 20 ensure in the wetting area of the brush a good uniform contact between the flap of each envelope and the brush.

The deflector 2 has on its lower and upper edges two hooking tabs 22 and 23, extending opposite the brush 1. These tabs maintain the deflector on a vertical axis 24, opposite the edge of the deflector coming to nest in the mooring area. This axis 24 is held on the bottom plate 8. In addition, the deflector is resiliently biased to have possible pivoting freedom on its axis 24, with stop, by a spring 25 wound on a vertical lug 26 fixed in the support plate 8 and whose end strands are applied under pressure against the axis 24 and a shoulder 27 formed in the lower hooking tab 23. This elastic mounting with deflector stop allows insertion of its ribs in the grooves of the brush, adaptable up to a certain limit to the thickness of the envelope flaps.

In operation of the device, the water supply to the brush is dosed with the amount of water necessary to moisten the envelopes. This makes the device safe and reliable whatever the speed of travel of the envelopes, their cadence and their length. Driving the flaps of the envelopes, which the brush itself performs, at substantially the same speed as that of the body of the envelopes, minimizes the risk of damaging the envelopes or removing rubber from the flaps and contributes to making the device very reliable. In addition, while the contacting of the flaps against the brush is effected by the penetration of the ribs of the deflector in the grooves of the brush, the absence of flaps against the brush does not cause any problem of damage or wear of the brush and water transfer on the deflector itself in particular due to the non-contact between the deflector and the brush despite their nested arrangement.

The device according to the invention is moreover particularly easy to assemble and maintain, and does not present a risk as regards possible dispersion of water in the machine which it equips.

Claims (7)

1. A device for moistening the closure flaps of envelopes during their displacement in the direction of their lengths along a substantially horizontal trajectory, comprising a rotating moistening roller (1), referred to as brush, and an associated deflector (2), for receiving therebetween the flaps of successive envelopes, and a means (3) for feeding a moistening liquid to said brush from a remote liquid tank, characterized in that said brush (1) has its axis disposed substantially in the vertical direction and is mounted together with said deflector flap (2) underneath the trajectory, upon which the envelopes move on the flat side with their flaps hanging substantially vertically, that said brush is constituted of a stack of alternating foam rings (17) and rigid rings (16) mounted on its axis, with the foam rings projecting beyond the periphery of the rigid rings and leaving between them a plurality of circular grooves (20) along the height of the brush, and that said deflector flap (2) comprises a plurality of ribs (21) meshing partially with the respective grooves of the brush within a moistening zone (10) in order to ensure the application of the flaps under pressure unto the foam rings and their moistening without the deflector flap contacting the brush.

2. A device according to claim 1, characterized in that said feed means is coupled to said brush in a zone of said brush (1) referred to as feed zone (11) and situated substantially opposite the deflector flap and in the upper area of said brush on its vertical axis, and that it further comprises an associated liquid distributor (73) urged against the brush over its height between the feed zone and the moistening zone.

3. A device according to claim 2, characterized in that said feed means comprises a pump (4) with a controlled throughput.

4. A device according to claim 3, characterized in that said brush (1) is coupled to a motor (9) which ensures its driving into rotation at a peripheral speed, that is substantially equal to the passage speed of said envelopes on said trajectory.

5. A device according to claim 4, characterized in that said pump (4) is a peristaltic pump coupled to said motor (9), which ensures its drive as well as that of the brush (1).

6. A device according to any one of claims 2 to 5, characterized in that said brush (1) and said deflector flap (2),are borne by a base plate (8), which forms a gutter (80) underneath said brush (1).

7. A device according to claim 6, characterized in that said gutter (80) communicates with said tank (3) and has a ramp for the purpose of said communication.

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