Feed device for feeding mail items of various dimensions

A mail item feed device having a first or mail item feed area, a second or selector area and a third or conveyor area and including a first plurality of sensors for identifying the various formats of the mail items present in said first area, a second plurality of sensors for detecting the passage of the mail items in said second and third areas, and a plurality of drive means for co-operating with the transport rollers of the first, second and third areas and actuated selectively in a predetermined sequence defined by control means in accordance with the state of each of the first and second plurality of sensors.

FIELD OF THE INVENTION 
The present invention relates exclusively to the field of mail processing, 
and is more particularly concerned with a device for feeding a postage 
meter (or "franking machine") with mail items of various dimensional 
characteristics, and especially items of various lengths. 
PRIOR ART 
Conventionally, a franking machine must be adapted to receive mail items of 
various types, such as documents, letters, or envelopes of various 
dimensions. To this end it often includes on the upstream side of a slot 
for inserting such items, a feed device for conveying envelopes with the 
flap folded down or folded open, and for doing so at various speeds. That 
automatic feed device, or feeder, usually includes means for 
receiving/stacking, selecting, transporting and possibly closing mail 
items that must afterwards be processed by the franking machine. 
Patent EP 581 392 describes a feed device of the above kind for stacked 
items, including a hopper part and transport means. Said transport means 
feed the articles both towards the front, and laterally using inclined 
rollers. Said transport means co-operate with said hopper part to cause 
the fed items to be arranged like the scales of a fish. 
The use of a rear jogger system in the hopper part complicates the loading 
of the feeder with mail items. It also requires the presence in the hopper 
part of mail item transport means associated with means for referencing 
and stacking said mail items beforehand. 
OBJECT AND DEFINITION OF THE INVENTION 
The essential aim of the present invention is to overcome the above 
drawback by proposing a particularly reliable mail item feed device 
adapted to be disposed on the upstream side of a franking machine to 
facilitate the feeding thereof with mail items of various sizes and not 
requiring any rear jogger means. Another aim of the invention is to enable 
active control of the routing of mail items in the feeder for optimum 
control of the drive means by which said items are transported. 
The above aims are achieved by a device for feeding mail items adapted to 
be mounted on the upstream side of a franking machine and including in 
succession along a transport path of said mail items a first or mail item 
feed area for receiving a stack of mail items of various formats and 
including a first plurality of transport rollers, a second or selector 
area for individually selecting said mail items and including a second 
plurality of transport rollers, and a third or conveyor area for conveying 
the items extracted individually from the stack of mail items one by one 
and directing them to the franking machine and including a third plurality 
of transport rollers, the device including a first plurality of sensors 
for identifying the various formats of the mail items present in said 
first area, a second plurality of sensors for detecting passage of the 
mail items through said second and third areas, and a plurality of drive 
means adapted to co-operate with said pluralities of transport rollers and 
actuated selectively in a predetermined sequence defined by control means 
according to the state of each of said first and second pluralities of 
sensors. 
This specific structure enables the feed device of the invention to process 
mail items of various dimensions in a particularly reliable manner. 
Starting/stopping each of the feed means co-operating with the various 
transport rollers in accordance with the states of the various sensors 
optimizes the use of the drive means and consequently significantly 
increases their service life and that of the feed device as a whole. 
Furthermore, the invention takes into account the format of the mail items 
and this influences the operating cycle time, which is of prime importance 
given that the postal imprint must be applied at a standardized distance 
from the edge of said mail items. 
In accordance with the invention the first plurality of sensors determines 
a predetermined mail item format. The first plurality of sensors 
preferably includes a first format sensor C5 at the entry of the feed area 
for determining large format mail items, a second format sensor C3 at the 
exit of the feed area for determining small format mail items, and a third 
format sensor C4 in a middle area of the feed area for determining medium 
format mail items. 
In a preferred embodiment, each of the sensors of the first plurality of 
sensors C5, C4, C3 for determining mail formats is a reflective type 
sensor. 
In accordance with the invention, each of the sensors of the second 
plurality of sensors determines the passage of a mail item at a 
predetermined location. The second plurality of sensors preferably 
includes a first or selector sensor C2 at the exit of the selector area, 
and a second or conveyor sensor C1 disposed further downstream in the 
conveyor area. 
In a preferred embodiment, each of the sensors of the second plurality of 
sensors is an opto-mechanical type sensor actuated by the passage of the 
edge of a mail item. 
The plurality of drive means advantageously includes a first clutch E1 in 
the selector area and driving transport rollers of the selector area and 
second and third clutches E2, E3 in the feed area and driving transport 
rollers of the feed area. The second and third clutches respectively and 
independently drive separate first and second sets of transport rollers of 
the feed area. 
The clutches are preferably driven via a set of cogs and belts from a 
single drive motor which also drives the transport rollers of the conveyor 
area.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 
The mail item feed device from FIG. 1 includes a feed area 10 essentially 
formed of a plate 12 and a mobile lateral wall 14 and adapted to receive a 
stack of mail items with various dimensions having flaps that are folded 
down or not. This area includes first transport means including a 
plurality of rollers 16 for moving the mail items in the downstream 
direction in a separator and transport area 18 including selector means 
including a presser and a throat (not shown) and a plurality of rollers 20 
and from which said items are extracted individually from the stack. 
Finally, second transport means including a plurality of rollers 22 are 
provided in a conveyor area 24 at the exit of said separator area to 
transfer further downstream the mail items extracted in this way one by 
one, for example, to a mail item closing area 26, if the feed device has 
one. The feed device further includes various control and monitoring means 
known in themselves (not shown except for a main drive motor 28 and a 
microprocessor-based control unit 29) necessary for it to operate (in 
particular for it to actuate the various rollers during the routing of 
mail items along a transport path 30) and which there is therefore no need 
to describe in more detail. 
FIGS. 2 and 3 show in more detail the internal structure of the feed device 
of the invention. The latter includes, in succession, in the direction in 
which a mail item is advanced along the transport path 30, three sets 100, 
102, 104 of three transport rollers 16 mounted on three parallel rotation 
shafts 106, 108, 110 substantially perpendicular to the transport path 30 
in the feed area 10, four sets 180, 182, 184, 186 of three transport 
rollers 20 also mounted on four parallel rotation shafts 188, 190, 192, 
194 perpendicular to the transport path 30 in the selector area 18, and 
two sets 240, 242 of three rear and front transport rollers 22 mounted on 
two parallel shafts 244, 246 in the conveyor area 24. The sets of 
transport rollers of the separator area and the conveyor area are adapted 
to co-operate with a selector module 300 (FIG. 3) and conveyor rollers 310 
(FIG. 3) respectively to select and to transport the selected mail item, 
possibly as far as the closing module, or to the entry of the franking 
machine if the feed device does not have any such closing module. 
The various transport rollers are driven from the main motor 28 via various 
drive means formed of cogs, belts and clutches. For example, the output 
shaft of the motor 28 is connected by a first cog 22 to the shaft 246 on 
which the front conveyor rollers 22; 242 are mounted and this shaft is 
itself coupled to the shaft 244 on which the rear conveyor rollers 22; 240 
are mounted by a first belt 34. A second cog 36 also connected to the 
output shaft of the motor 28 drives a first transmission shaft 38 which 
via a second belt 40 drives a second transmission shaft 42 on which are 
mounted a first clutch 44 and a third cog 36. This cog 46 meshes with a 
fourth cog 48 mounted on a third transmission shaft 50 and which itself 
meshes with a fifth cog 52 mounted on a fourth transmission shaft 54. 
These various cogs are adapted to co-operate with four corresponding cogs 
56, 58, 60, 62 with rotation shafts 188, 190, 192, 194 on which are 
mounted the transport rollers 20 of the selector area 18. Note however 
that all the rollers of the selector area (which are then driven with the 
rollers of the conveyor area) can be driven only if the first clutch 44 
(E1) is activated. The cog 62 mounted on the rotation shaft 188 nearest 
the feed area 10 meshes with a first intermediate cog 64 which in turn 
meshes with a sixth cog 66 mounted on a fifth transmission shaft 68 which 
also carries a second clutch 70 (E2). A seventh cog 72 also mounted on the 
fifth shaft 68 meshes through a second intermediate cog 74 with a cog 76 
fastened to the shaft 110 on which are mounted the feed rollers 16; 104 
nearest the selector area 18. This shaft carries another cog 78 which, via 
a third intermediate cog 80, drives an eighth cog 82 mounted on a sixth 
transmission shaft 84 which also carries a third clutch 86 (E3). The sixth 
transmission shaft also carries a ninth cog 88 which meshes via a fourth 
intermediate cog 90 with a cog 92 fastened to the shaft 108 on which is 
mounted the second set (or central set) of feed rollers 16; 102. This cog 
92 drives a cog 99 driving the shaft 106 on which are mounted the feed 
rollers 16; 100 at the entry of the feed area 10 via three other 
intermediate cogs 94, 96, 98. Note that the second clutch E2, when 
activated, drives the rollers of the last set 104 (those at the exit from 
the feed area) at the same time as those of the selector and conveyor 
areas and that the third clutch E3 drives all the rollers of the feed area 
conjointly with those of the other areas of the device of the invention 
when it is activated in its turn. 
The set 240 of transport rollers 22 of the conveyor area nearest the 
selector area 18 includes a first sensor 120 (C1) for sensing the presence 
of a mail item at the entry to the conveyor area 24. Similarly, one set of 
transport rollers 20 of the selector area 18, advantageously the set 186 
nearest the exit from this area, includes a second sensor 122 (C2) for 
sensing the presence of a mail item in the selector area, preferably at 
the exit from that area. Each of these two sensors, which are 
advantageously of the opto-mechanical type, includes a flag or shutter 
124, for example, which is actuated by the passing edge of the mail item 
and rotation of which interrupts the light path of a light-emitting diode 
(or between light-emitting diodes) contained in a housing 126 attached to 
the body of the feed device. 
Three other sensors are disposed in the feed area 10 to sense the format of 
the mail items. A third sensor 128 (C3) is preferably placed at the exit 
from this feed area at the location of the third set 104 of transport 
rollers 16 to sense small format mail items (up to approximately 160 mm). 
Similarly, a fourth sensor 130 (C4) is placed substantially towards the 
middle part of this area at the location of the second set 102 of 
transport rollers 16 to sense medium format mail items (in the range about 
160 mm to about 240 mm). Finally, large format items (more than 
approximately 240 mm) are sensed by a fifth sensor 132 (C5) preferably 
placed at the entry of the feed area at the location of the first set 100 
of transport rollers 16. Of course, this number of sensors is in no way 
limiting on the invention: it is entirely feasible to use a greater or 
lesser number of sensors and in particular to provide as many sensors as 
there are mail item formats to be sensed. 
The operation of the device of the invention is described with reference to 
FIG. 4 which is a flowchart detailing the sequence of operation of the 
clutches in accordance with the states of the various sensors. 
After an initial step 1000 of initializing various parameters necessary to 
the operation of the device, step 1002 entails reading a control input 
that can be actuated by an operator and corresponds to the required mode 
of operation for the processing of mail items (automatic or manual), after 
which the main motor 28 is started (step 1004). The states of the sensors 
C1 through C5 are then determined (step 1006) and the format of the mail 
item is obtained in the next step (1008) on the basis of the states of the 
three sensors C5, C4, C3 in the feed area. If the sensors C5, C4, C3 are 
active, this indicates the presence of large format mail items in the 
device. On the other hand, if C5 is inactive and C4 and C3 are active, 
medium format items are present. The presence of small format items is 
indicated by C3 alone being active and the absence of any item in the 
device by all three sensors C5, C4, C3 being inactive. At the end of this 
format analysis step, the set of clutches E1, E2, E3 is commanded (step 
1010) to cause the mail items to be advanced towards the selector area 18 
and then, depending on the states of the last two sensors C2 and C1, their 
successive disabling. Thus, if only C3 remains active when C2 becomes 
active (i.e. in the presence of a small format item) the clutches E2 and 
E3 are stopped. On the other hand, if C3 and also C4 are still active 
(medium format) only the clutch E3 is disabled. Finally, if all three 
sensors of the feed area are still active when the mail item reaches the 
sensor C2 of the selector area, indicating the presence of a large format 
item, no action is taken at the clutches, which continue to transmit 
drive. Similarly, when this mail item reaches the last sensor C1 of the 
conveyor area the clutches still operating are stopped (note that if C1 
does not become active after a predetermined time, which could indicate a 
jam at the selector module or sensing of the presence of multiple 
documents, for example, an error procedure is initiated in step 1012). 
Unless only the sensor C5 is still active, in which case the clutch E3 is 
first disabled and then the clutches E2 and E1 are also disabled after a 
predetermined time-delay (for example a time-delay of 70 ms for envelopes 
more than 240 mm long), the length of the mail item is then measured (step 
1014) to enable close control of the spaces between items. This 
measurement is effected in a manner known in itself by a pulse encoder on 
the motor 28. Finally, according to the operating mode entered in step 
1002, the motor is stopped in step 1016 (manual feed mode) or the system 
loops on determining the states of the sensors (step 1006). 
The structure of the invention assures optimum control of the clutches and 
consequently minimizes the use of the main motor of the device to which 
these clutches are coupled. This significantly improves the reliability of 
the feed device of the invention. 
Freewheels 89, 73, 47 can be disposed on the transmission shafts 84, 68, 44 
to allow easy evacuation of the mail item in the downstream direction 
despite the sequenced stopping of the clutches E3, E2, E1. 
Optimum control of the clutches assures convenient control of and optimizes 
the distance between two consecutive envelopes. The electronics can also 
be programmed flexibly to adapt the feeder to a specific machine base, in 
particular in terms of throughput.