CH678161A5 - - Google Patents

Description

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Description

The present invention relates to a device for composing printing wheels for a franking apparatus according to the preamble of claim and a franking apparatus comprising such a device.

Electronic franking devices of the plate printer type are known; these are described, for example, in United States patent No. 579,054, which shows an isolated electronic mail dispatch machine in which the electronic franking apparatus constitutes an integral part of the device. Other aspects of such a machine are described in US Pat. Nos. 535,407 and 4,523,523, among others.

A particular concern with postage meters and high-speed mail machines is the speed with which print wheels can be set to a new value. U.S. Patent No. 4,034,669 teaches the use of a separate stepper motor for each printing wheel in the printing drum of a rotary type franking apparatus. U.S. Patent No. 4,398,458 shows a composition device for printing wheels in a printing drum in which separate stepper motors are used for each wheel. U.S. Patent No. 4,451,053 describes a process for the parallel composition of printing wheels.

The matrix protection assemblies incorporate various mechanical arms which protrude from the area of the matrix having the print wheel so as to prevent a person from simply placing an envelope against the matrix to obtain an impression.

U.S. Patent No. 2,795,186 shows a movable shield that can be lowered to protect the die from unauthorized printing at any time between printing operations. The shield completely covers the face of the printing matrix of the values when the printing mechanism is not in an operating cycle and is locked in this position until the beginning of the cycle, instant at which the shield moves until at a position where the matrix is discovered. U.S. Patent No. 4,559,444 teaches an interposition arrangement which extends in the top direction from the plate to enter the space in which an envelope is to be inserted. These interposition arrangements are cleared from the path during a legitimate printing operation. The blades of the interposition arrangement are mechanically linked to the inking mechanism so as to release them from the path while the mail fold comes to its printing position. U.S. Patent No. 4,796,526 and U.S. Patent No. 4,796,527 to the Applicant describe interposers which are related to the engine driving the piatine of the printer to clear it from the route,

or are actuated by a power switch so that they are clear of the path as long as the machine is powered on.

While these known devices work well in particular environments in which it is not expected that the stage and the matrix are physically separated, in a modular device where the device with its security matrix can be removed from the together in which the plate is maintained, several new security provisions are created with regard to the franking apparatus of the type with tray printer.

The electronic franking apparatus of the present invention is a tray type printing apparatus which can be removed from the mailing machine and in which new protective features of the matrix have been incorporated in order to protect it when the device is removed and the plate remains with the shipping machine or base.

In a preferred embodiment, the franking apparatus of the present invention includes three independent mechanisms for protecting the matrix to prevent fraudulent printing. To get the best results, the machine will not actually print, but instead will allow printing by the shipping machine, during a narrow "window" of time when all of the matrix protection is removed,

According to the present invention, the first matrix protection device comprises a sliding plate which completely covers the printing elements when the franking machine is removed from the mailing machine. In a preferred embodiment, this plate can only be retracted if the postage meter is in place on a legitimate shipping machine. The second protection device includes matrix protection blades or interposition arrangements which are adjacent to two of the print wheels, preferably to the high order print wheels. They are locked in a position where they protrude beyond the printing surface each time a withdrawal solenoid is de-energized. This mechanism protects the matrix against printing whenever the franking machine is not validated and ready to print. The third protection mechanism, here called the alignment / protection mechanism, is similar to the second, but it is activated separately, and is locked in place at all times with the exception of a “window” controlled over time when the impression takes place. It is envisaged that postage accounting will take place at the start of each such "window".

When the franking machine is removed from its machine, the three matrix protection mechanisms are unconditionally in place, and access to the matrix is not possible for printing or any other purpose. After installation on the machine, the matrix protection is selectively removed as follows:

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1. A successful installation has the effect of retracting the matrix cover plate;

2. When the conditions of eligibility for printing are satisfied, that is to say when there is a suitable power and sufficient funds, etc., the protective blades of the matrix are retracted, and finally ,

3. The alignment / protection blades are only temporarily removed at the time of each posting if the necessary conditions are satisfied.

When properly installed on the mailing machine, during all normal operations, the franking machine communicates with the mailing machine via a communication channel. In a preferred embodiment, the shipping machine will transmit a request for the apparatus to lift its protective / alignment devices from the die so that an impression can be made, and that an invalidated apparatus may reject the request and avoid all printing attempts.

The present invention will be clearly understood from the following description in which:

Fig. 1 is an external perspective view of an electronic franking apparatus according to the present invention;

fig. 2A is a perspective view of a postage meter according to the present invention, shown in place on a mailing machine;

fig. 2B shows a way of removing a franking apparatus according to the present invention to take it out of the mailing machine;

fig. 3 is a bottom view of the franking apparatus which shows the sliding shutter covering the matrix when the franking apparatus is removed from the mailing machine;

fig. 4A is a perspective view of the Impression matrix and a dead bolt actuated by solenoid, with the shutter sliding in the closed position, Other internal assemblies of the apparatus, with the exception of the matrix, are not shown for simplicity;

fig. 4B is a perspective view of the franking apparatus similar to that of FIG. 4A, showing the shutter sliding in its retracted position;

fig. 5 is a side view of a first embodiment of an actuation-removal mechanism for fixing the postage meter to the mailing machine;

fig. 6 is a side view of an alternative embodiment of the actuation-removal mechanism;

fig. 7 is a partially exploded view of an appropriate internal configuration of the franking apparatus according to the present invention;

fig. 8 is a block diagram of a computerized franking apparatus; fig. 9 is a block diagram of the communication between the mailing machine and the postage meter;

fig. 10 is a flow diagram of a communication program for releasing the deadbolt and allowing the retraction of the sliding plate;

fig. 11 is a side view of the composition mechanism of the printing wheel in the franking apparatus;

Fig, 12 is a sectional view taken along line 12-12 of Fig. 11;

fig. 13 is a sectional view taken along line 13-13 of FIG. 11;

fig. 14 is a sectional view taken along line 14-14 of FIG. 11;

fig. 15 is an embodiment of a matrix protection arrangement, in which the matrix protectors are arranged at a location contiguous to the high order print wheels;

fig. 16 shows an embodiment in which there is an alignment / protection mechanism for the lower order printing wheels;

fig. 17 is an operating flow diagram of the matrix protection blades for high order print wheels;

fig. 18 is a flow diagram of the operation of the alignment / protection blades;

fig. 19A to 19H include a flow diagram for the operation of the composition mechanism of the print wheels.

In fig. 1, there is shown at 10 an electronic franking apparatus according to the present invention. The cover 12 of the housing 14 houses a keyboard and a display device 16. The keyboard and the display device are suitably similar to those shown in U.S. Patent No. 4,097,923, incorporated herein by reference title. Preferably, the keyboard is of the conventional monolithic type and the display device is a liquid crystal device having a capacity of twelve digits. It will be noted that the keys of the franking apparatus and the display of the postage meters are not necessarily limited to those shown here and can be modified to meet the needs of the franking apparatus. When the apparatus 10 is installed on a mailing machine, the keyboard and the display device can be hidden from the operator's view.

Fig. 2A is a perspective view of the franking apparatus 10 mounted in a mailing machine or base 18 of the apparatus. The mailing machine 18 comprises a printing plate 20 driven and reciprocated by a motor 22 by means of a pinion and rack mechanism 24. A cover 26, when it is closed during normal operation, covers the franking machine. An introductory module 28 introduces the mail folds into the base 18 which routes them to a closed space between the printing matrix 30 which bears the signs of the franking apparatus and the plate 20, following of which, with an alternating movement of the plate upwards, an impression of the signs is carried out on a mail fold such as fold 32, re5

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presented as being ejected from the mailing machine.

The drive arrangements of the plate are well known and are, for example, shown in US Pat. Nos. 4,579,054 and 2,795,186. Note, however, that with regard to the apparatus for franking of the present invention, the plate 20 constitutes a part of the base 18 and the franking apparatus 10 comprises only the printing matrix 30. The mail sending machine will not be described further in exception of the parts necessary for the operation of the device 10.

In the preferred embodiment, the printing matrix is an elastomer matrix so as to obtain the best possible quality of printing for a given force exerted on the platen. It will be noted, as is well known, that the printing matrix must be inked to print the signs. Inking mechanisms are known and these are also represented in the patents of the United States of America which have just been cited. Preferably, the inking mechanism (which is not shown) also remains integral with the base 18. It will be noted that this mechanism could constitute a part of the franking apparatus.

Fig. 2B shows the franking device when it is removably mounted on the base 18. The device is inserted into a cell 34 which is pivotally mounted on the base 18. When the device is inserted into the cell 34, a connector 36 of the cell mates with a corresponding connector 38 (not shown in FIG. 2B) of the franking machine 10.

The connectors 36 and 38 serve to establish communication between the shipping machine 18 and the apparatus 10, and also preferably make it possible to supply the franking apparatus. A suitable communication system is described in U.S. Patent No. 4,301,507, which is incorporated herein by reference. The communication between the units as described in this patent is an asynchronous communication by serial characters, synchronous bits, in the form of messages, with the bits of the timed messages in accordance with a given program for a synchronous command. It will be understood that one can alternatively use other procedures and communication devices well known in the art, where appropriate.

Now in connection with FIG. 3, which shows a view from below of the franking apparatus, a sliding plate or shutter 40 is slidably mounted on the housing 12 and locked in the closed position illustrated by means of a deadbolt 42, preferably subject to a spring which extends into a hole 44 formed in the shutter 40. The shutter is released by actuation of a solenoid 46 (shown in the embodiment illustrated in FIGS. 4A and 4B), but it will be noted that one can use, as a variant or in addition to the deadbolt actuated by solenoid, a means such as a locking mechanism controlled by motor, actuated by cam.

Figs. 4A and 4B are perspective views of the franking apparatus with the shutter 40 shown as covering the printing matrix 30 and in the retracted position, the matrix being exposed.

In order to avoid access to the deadbolt 42 from the outside, it will be noted that the hole 44 may be a blind hole or a bore made in the interior of the shutter 40.

As noted above, the franking apparatus of the present invention is a tray printer with elastomeric printing dies, and the platen and the inking mechanism preferably remain integral with the machine. expedition. In order to protect the printing matrix in such a configuration, whenever the postage meter is removed from the mailing machine, in accordance with the present invention, all the printing elements are automatically covered by the shutter 40. This shutter which covers the matrix is only retracted, as discussed above, when the franking apparatus is in place on an authorized shipping machine, the cover of the matrix or shutter 40 constitutes one of three independent mechanisms for protecting the matrix.

It should also be noted that the matrix will remain protected against fraudulent printing by the other protection mechanisms, However, the exposure of the printing matrix 30 could be further violated to modify certain designs of the signs or to allow its damage or exposure. operator with ink from the matrix.

Fig. 5 is a side view of an embodiment of an on-off mechanism for the franking apparatus. A carrying handle 48 (not shown in the previous figures) is pivotally mounted on the apparatus 10 to an axis 50. A slot 52 formed in the handle can be used to receive a coupling pin (not shown) from the base 18 when the appliance pivots down as illustrated in fig. 5, and that the handle 48 is rotated in a clockwise direction. It will be noted that at this junction, the franking apparatus 10 is connected to the base 18 via the connectors 36 and 38 and is locked to the base by engagement in the slot 52 of the axis of base coupling.

With the franking apparatus and the base placed in the operating position, communication is established and by the use of messages of "connection establishment" between the franking apparatus and the base, there is determination that a correct franking apparatus is in the rest position on a legitimate basis, therefore the latch 42 (not shown in fig. 5) is retracted, preferably only for a predetermined period. retracted, the shutter 40 can be moved rearward (to the right of Fig. 5). In the illustrated embodiment, this is done by means of a flexible cable 54 comprising a handle 56 that the operator can grab.

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The cable is suitably mounted on the cell 34 by convenient means (not shown). The other end of the cable is connected to a traction slide 58, slidably mounted on the base 18 by means of a convenient means (also not shown). The side wall 60 supports an axis 62 and an axis 64. With the franking device in the rest position, that is to say in the lower position illustrated, the axis 62 engages in the slot 66 of the slide 58. When the slide 58 is moved by the operator by pulling the flexible cable forwards, the shutter 40 will also be retracted to reveal the printing matrix represented at 30.

During the movement of the shutter 40, the axis 64 will engage in the slot 67 of the handle 48 to prevent the device from being lifted from its operating position when the shutter is retracted. Thus, to remove the device 10, the operator must push the flexible cable forward so as to push the shutter 40 to put it in position, again covering the matrix 30. The deadbolt 42 is biased by spring and re-engages in the hole 44 of the shutter to block the latter in the safety position.

Other methods and devices can be used to retract the shutter. Fig. 6 shows an alternative embodiment in which the franking apparatus has been installed by lowering it vertically into the base. In fig. 6, the mechanism is shown in its middle position after installation of the franking device and locking in position but before the withdrawal of the shutter.

The device represented in this embodiment is placed vertically on the base in the downward direction with the square axis 100 of the device being at its front and the axis 110 of the handle 120 released for an upward and downward movement. of the device in relation to the base. A cam surface 130 of the device captures the axis 110 and while the lever is pulled by the operator towards the front of the device, the vertical part of the cam surface 130 is pushed towards the operator of so that the axis 100 engages in the slot 140. At this stage, the device is locked in place and the communication between it and the base is established as described in connection with FIG. 5. With "the appropriate establishment of the connection", the deadbolt rises to allow a new movement of the handle. A pin 160 which is mounted on the shutter is also brought into contact with a wall 170. Preferably, a lip or inclined element shown at 200 also engages in a slot 210 to block the device on the base.

As the handle 120 continues its forward movement, a sector 220 is engaged with a pinion 230 which drives a rack 240 fixed to an element 260 which supports the wall 170. The plate of the shutter is moved towards the rear by the action of the wall 170 on the axis 160 until the handle is stopped by the cam surface 130 and the shutter has exposed the printing matrix.

Other means for blocking in place the franking apparatus and for effecting the withdrawal of the shutter can be envisaged depending in part on the manner in which the apparatus is to be installed. It will be noted that the various operations for removing the shutter which have been described here as being carried out by the operator can be motorized, if necessary.

The flg. 7 is a partially exploded view of a franking apparatus according to the present invention. The apparatus 10 is shown with the cover 12 and the keyboard and the display device raised relative to the bottom to expose the arrangement of the equipment of the apparatus. The connector 38 is coupled to printed circuit boards 300 which include the functions of accounting and printing control which are described below. Print wheels 310 are driven by stepper motors 320 in an arrangement which is also described below. A date set 330, a counter 340 and a slogan printer 350 are also provided as required. Preferably, a door 360 allows access to printers.

Fig. 8 is a block diagram of a computerized franking apparatus. The system is controlled by a microprocessor which basically comprises a central unit (CPU) performing the functions of accounting, controlling the composition of the print wheels, protecting the matrix and communicating with the base and the other necessary peripherals. Three types of memory assemblies are used with the CPU. A permanent memory PM which can be a read only memory (ROM) or a programmable read only memory (PROM) stores the sequence of the operations of the program to be executed by the central unit for its accounting calculations and its control functions. A temporary memory TM which is a selective access memory (RAM) stores the data and the results of the calculations on a temporary basis until they are stored in a non-volatile memory NVM. This memory can be a selective access memory, an erasable programmable electronic memory, an electrically alterable read-only memory, or a silicon metal-nitride-oxide memory with auxiliary battery, or be any combination if two or more memories are used. Preferably, at least two non-volatile memories are used and the accounting data of the transaction is stored in a non-volatile memory for each transaction.

A suitable method for such accounting is shown in United States Patent No. 4,484,307. Other accounting methods are described in United States Patent No. 3,978,457. funds may also be placed in a memory or be extracted from a memory by a means such as that described in United States Patent No. 4,097,923, more especially incorporated herein by reference.

The system according to the present invention can operate in accordance with a data entry via the keyboard and the vi5 device.

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line 16 and display information thereon, or it can receive and transmit information to the mailing machine or other device via the connector 38 as shown in FIG. 9. The keyboard and the display device could, in a preferred embodiment, be used only for reading the various registers of the franking apparatus and / or for replenishing the fund of the apparatus and for various checks. and accounting operations that may prove necessary • when the franking machine is not installed on its base. When the device is mounted on its base, the central unit, in accordance with the data it receives from the base, operates the stepper motors 320 for the composition of the printing wheels 310 shown in fig . 8 by a block SP and also controls the other protection devices of the matrix so that the printing of the franking can take place. These operations are indicated in a PP block.

Fig. 9 is a block diagram of the communication between the franking machine 10 and the mailing machine 18. As mentioned previously, it is preferred that all communications take place via the protocol described in U.S. Patent No. 4,301,507.

Fig. 10 is a flowchart for the release of the deadbolt 42 allowing the withdrawal of the shutter. Once it has been determined that the postage meter is on an appropriate base, the solenoid is operated for a predetermined period of time to allow the operator to move the shutter.

Figs. 11 to 14 show the composition mechanism of the printing wheels. This mechanism includes five gear trains driven by motors. Five stepping motors (each designated by the reference 320 because the motor trains are similar for each printing wheel) are mounted on walls 400, each motor driving an associated printing wheel 310 via respective pinions 410, gears 420 encoder, transfer gears 430, and print wheel gears 440 attached to the wheels 310. Each gear train has a two-channel sensor-encoder designated by 480. The 420 encoder gears, made of material molded plastic, include 10-tooth gears which engage the transfer gears 430 and twenty-tooth gears which engage the pinions 410 along with flat wheel parts that extend into the detectors 480 .

Each detector channel comprises a source, for example an infrared emitting diode and a detector, a photodiode with its associated circuit. Such detectors are conventional and will not be described further.

Preferably, the encoder wheel operates to produce ten transitions per revolution as it passes through the detector and through each detector channel alternately blocks and unblocks radiation from the source. This results in two transitions in the detector (one for each channel of the two-channel detector) for each movement of a digit. '

The channels of which are physically separated so that during the rotation of the encoder wheel, the detector outputs are in quadrature phase (the output of one of the detectors is ahead or behind the output of the other detector d 'a quarter cycle).

The pinions 410 of the motors are twelve-tooth pinions fixed to their shaft and are engaged with the gears 420 of the encoders.

The 320 stepper motors execute a full revolution in 24 steps; this, by transmission by the previously described gear train, requires 4 steps of the motor for the displacement of a digit of the printing wheel. In this embodiment, the stepping motors are four-phase motors preferably driven by drive circuits in a two-phase mode. The engine control sequence is discussed below in conjunction with the print wheel composition flowcharts.

Each print wheel 320 is conveniently a component made of plastic material which forms a substrate for the molded rubber print characters placed on the periphery of the wheel, this periphery being designated by the reference 450. The print wheel also comprises a 10 tooth 440 gear which is also used as described below for alignment of the print wheel during printing.

It will be understood that the composition mechanism also takes into account the decimal point offset between the printing wheels of the middle digit and the printing wheel of the last significant digit to obtain the various required postage values.

Transfer gears 430 are thirty-tooth gears, suitably of molded plastic, which engage the gears 440 of the print wheels and the gears 420 10-tooth of the encoder. The transfer gears have a projection 460 which in conjunction with a fixed member 470 of the housing provides an end stop or zero reference position for the mechanism.

When the projection 460 of the transfer gears is contiguous with the stopper 470, there is a fixed value known on the plane of the printing matrix. Note that with the 30 teeth of the transfer gear engaged with the 10 teeth of the print wheel gear, there will be three rotations of the print wheels for one rotation of the transfer gear. . Due to the particular implementation of the end stop, in this embodiment there are 26 positions of the transfer gear which correspond to the positions of the 10 digits of the printing wheel. According to the present invention, it takes advantage of the fact that a particular composition of the digits is available at a multitude of positions of the transfer gear in order to obtain the shortest possible path of movement of the transfer gear and to carry out the

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composition of characters on each print wheel.

In the embodiment shown in these figures, a solenoid 490 lifts the tandem blades 495 for protecting the matrix so as to allow the printing of the postage value. While this arrangement normally works well in conventional tray printers, there is further provided in the franking apparatus of the present invention further protection of the matrix as shown more particularly in connection with Figs. 15 and 16,

Fig. 15 is a perspective view of the protection mechanism of the matrix. According to the present invention, two blades 500 and 510 for protecting the matrix are placed at a place contiguous to the two highest order printing wheels of the group 310 of wheels. When the franking machine is logically incapable of accepting a printing request, these two blades protrude beyond the printing plane of the printing elements in order to avoid the execution of fraudulent printing by the matrix.

The special conditions under which, for example, the franking machine can be invalidated include lack of supply, insufficient funds, selection of a current value in which the order print wheels high must be moved and various error situations that are detected.

As shown in fig. 15, the blades 500 and 510 are pivotally fixed to a shaft 520 and at the opposite end are engaged via an axis 530 which is held in an S-shaped slot 540 formed in an element 550 fixed to the frame 560 of the 570 solenoid. The 570 solenoid is under the direct control of the microprocessor. When the solenoid is energized, it attracts the element 550 against the force of a spring (not shown) and the upper part of the slot 540 lifts the protective blades of the matrix. The blades will remain in the withdrawn position until the microprocessor de-energizes the solenoid or until there is no power. When the blades are retracted, they perform the other function of holding the two high order printing wheels to improve their alignment,

Fig. 16 shows an additional matrix protection mechanism which includes a set of protruding blades, referred to herein as alignment / protection blades, which are recessed only for a short period of time during each printing operation. Preferably, this withdrawal coincides with the accounting operation of the postage meter. According to the present invention, the alignment / protection blades, represented at 600, 610 and 620 are arranged near the lower order printing wheels. The three blades are normally locked in position as shown by the projecting tooth 630 of a rotating cam 640. A solenoid 650, when admitted under tension, rotates the cam 640 to release the tooth 630 and raise the blades d alignment / protection by coming into contact of a tooth 660 of the cam 640 with a tooth 670 of the protection blades of the matrix. The rotation of the cam 640 is also carried out against a spring (not shown) so that in the event of failure the cam will return to the blocking position.

It will be noted that the activation of these two types of protection of the matrix can be done by means of one or the other type of mechanism described here and is not limited to one or the other method insofar as blocking is obtained.

For operation, the three blades are normally locked in the projecting position and forces applied from the outside cannot cause them to be withdrawn. When the shipping machine communicates a print request, the postage meter will take the request into consideration and based on the availability of funds and other print criteria, and if accepted, will energize the solenoid and will cause the alignment / protection blades to be pulled out for a timed period during which the mailing machine can ink the matrix and print. Preferably, the alignment / protection blades perform the auxiliary function of maintaining and aligning the lower order printing wheels.

Figs. 17 and 18 are flow diagrams for the operation of the matrix protector and / or the guiding / protection mechanisms. The operation of each of them has been described and it is thought that it is not necessary to describe the flowcharts in more detail.

Figs. 19A-19H show the operation of the composition mechanism of the printing wheels shown and described in conjunction with FIGS. 11 to 14. The flowchart represents the operation of the mechanism to take advantage of the shortest route to the new composition. This is of great interest for increasing the speed of composition necessary for the throughput of a franking apparatus according to the present invention in order to reduce energy consumption.

Fig. 19A shows the normal franking program for the composition of the printing wheels of the franking apparatus. According to this program, a success flag (step 1) is first erased and a flag indicating whether the position of the print wheels is known is checked (step 2). If the known position flag (step 3) is initialized, a software initialization program is called (step 4). An SDIGITS subroutine calculates the distance of the digits for the five groups of printing wheels (step 5) and when this calculation is complete, a franking program, SSTEP, is called (step 6). At the end of this program, the position is checked again (step 7) and if it is known (step 8), the success flag is initialized (step 9).

Fig. 19B represents the SDIGITS subroutine which calculates the distance of movement and its direction that each wheel of numbers must travel by subtracting the value of the postage currently initialized, stored as old value from the desired value stored as new value (step 1). As mentioned in the discussion of Figs. 11 to 14, each printing position

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print wheel characters is associated with multiple positions of the transfer gears. Thus, in accordance with the program, with the exception of the moment when the initialization mechanism of the franking apparatus is itself initialized, ten (10) is added to the new digit (step 3) to place the new number in the central decade of the transfer wheel. The value currently composed in the print wheel is subtracted from the new value thus obtained to obtain the difference (DIFF) (step 4). The sign resulting from the subtraction is then stored (step 5) so as to determine the direction in which the print wheels must move.

A test is then carried out to find out whether the initialization is in progress (step 6). If so, the program returns to the main loop. If initialization is not in progress, the DIFF difference is tested to see if it is greater than five (5) (step 7). If DIFF is five (5) or less, the program returns to the main loop. If the test result shows that the difference is greater than five (5), the DIFF difference is tested again to see if it is greater, equal, or less than ten (step 8), If the result is equal to ten ( 10), DIFF is made equal to zero (0) and the program returns to the main loop. If it is greater than ten (10), ten (10) is subtracted from the difference (step 9), and the result is retested. If DIFF is then less than ten (10), the steering is tested (step 10) to see if the print wheels should move in the upward (11) or downward (12) direction.

If the wheel has to move in the upward direction, the initialized value plus (ten minus DIFF) is tested (step 3) and if it is less than or equal to twenty-six (26), the direction is reversed (step 14) and DIFF is made equal to ten (10) minus DIFF (step 15). Otherwise, the program returns to the main loop ”

If the direction is descending, then the initialized value minus (10 minus DIFF) is tested as being greater than or equal to zero (0) (step 16) and if this is the case, the direction is then reversed and DIFF is returned equal to ten (10) minus DIFF. Otherwise, the program returns to the main loop.

Fig. 19C represents the SSTEP subroutine. This subroutine will move the print wheels by the number of digits specified in the SDIGITS program and in the direction specified in this subroutine. In this subroutine, the known position flag is cleared (step 1) and the required number of steps is calculated by multiplying the distance of the digits by four (4) because the stepper motor moves by four (4) steps for each digit (step 2). The position of the wheel in the detector transitions is then calculated as twice the initialized value. This is determined for each group. At this junction, the SMOTOR subroutine (step 4) is called to supply the step pulses to the stepper motor to drive the print wheels. The position of the digit wheels is calculated from their position in the detector transitions which have been kept updated during the movement, divided by two (2), because as mentioned previously, there are two detector transitions per figure (step 5). The calculation is checked (step 6) to see if it is an exact multiple of two (2) and if it is not, an error program is called. If so, the Initialized value is stored (step 7). A program then follows to check whether the initialization is done (step 8), and if not, the printing value is made equal to the initialized value (step 9). The print value is checked to determine if it is greater than or equal to ten (10) (step 10); if so, the print value is made equal to the print value minus ten (10) (step 11) and is checked again.

If the print value is less than ten (10), the program verifies that the print value is now equal to the new value (step 12) and if not, a error program is called. If the answer is yes, the routine determines if there are any remaining groups to initialize (step 13). If there are any, the wheel position for the new group is checked until there are no more groups to check. The known position flag is initialized before returning (step 14).

Fig. 19D represents the SMO-TOR subroutine for supplying step-by-step pulses to each motor. Each motor receives output on a sequential basis during the composition cycle for groups of print wheels. For each group (step 1), * the motor steps are checked (step 2) and if they are greater than zero (0), an output is then initialized (step 3) so that the motor moves one step and an “exit ready” flag (step 4) and a “wait for timer” flag (step 5) are initialized. The SSENDS detector monitoring program is called (step 6) and a check is made to see if another group should be "initialized" (step 7).

If at the verification of the motor steps (step 2), the group indicates zero steps (0) to be carried out, the program connects to establish a data for the holding coil of the present position (step 8) and a holding counter is decremented (step 9). If the counter has not reached zero (0) (step 10), the program returns to the main SMÖ-TOR loop and the "output ready" flag and the "wait for timer" flag are initialized and the program for monitoring the detector is called again. If the counter has been decremented to zero (0), the flag is then initialized for zero (0) (step 11), and the "timer wait" flag is initialized with no "output ready" flag. The program runs until all the zero (0) flags are initialized (step 12), when it returns to the main loop.

Fig. 19E represents the SSENDS subroutine which monitors the detector channels so as to update the actual positions of the wheels. In this subroutine, each group detector is read (step 1) and there is determination that a transition has been made (step 2). If the answer is yes, the direction is determined (step 3) by checking the sequence of transitions from die 5

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CH 678 161 A5

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guard with two channels and if the direction is descending (step 4), one is subtracted from the position of the wheel (step 5) and if the direction is ascending (step 6), one is added to the position of the wheel (step 7). At this stage, the "timer wait" flag is checked (step 8) and if it is cleared, the program returns to the main loop. If the "wait timer" flag is not cleared, the next group is read.

If no transition is detected (step 2), there is then verification of the erasure of the "wait for timer" flag. If erased, the program returns to the main loop.

Fig. 19G represents the timer interrupt program.

Fig. 19F represents the subroutine for initializing the print wheels. In this program, the new value is made equal to twenty-six (26) for each wheel (step 1) and the transfer gear is driven to the stop. At this stage, the “known position” flag is checked (step 2) and if the “known position” flag is not initialized, the initialized value is set to zeros (0) (step 3). If the known position flag is initialized (step 4), the zeroing step is skipped.

The initialization flag is then set (step 5), the common initialization program is called (step 6) and the subroutines (steps 7 to 14) go on to check the positions of the print wheels in the middle and at opposite ends. At this stage, the initialized current franking is made equal to zero (0) (step 15) and after erasing of the initialization flag (step 16), the known position is tested (step 17), and if the position is known , the success flag (step 18) is initialized. Otherwise, the success flag is not and in both cases the program returns to the main loop.

Fig. 19H represents the CO-MIN subroutine, subroutine for a common initialization. This program is common to all the motor drive circuits and initializes the registers and sets the timer for interruption at predetermined times.

The present invention is not limited to the exemplary embodiments which have just been described, it is on the contrary liable to modifications and variants which will appear to those skilled in the art.

Claims (1)

Claims 1. Composition device for printing wheels for positioning a printing wheel of a franking apparatus (10), characterized in that it comprises: - a print wheel (310) having a multitude of print characters on its periphery; - a motor (320); - a gear train (410, 420, 430, 440), driving the motor to the print wheel; the gear train comprising at least one gear (430), such that a multitude of positions of this gear correspond respectively to a printing position of each character of the multitude of printing characters that the printing wheel comprises ; - means for determining the shortest rotation path of said gear in order to place it in a position where a desired character of the printing wheel is in the printing position; and - Means for actuating the motor in order to move said gear to said position following the shortest path. 2. Device according to claim 1, characterized in that the means for determining the shortest rotation path tends to place the gear in the median range of its rotation. 3. Device according to claim 1, characterized in that it further comprises a coding means (480) to allow the determination of the position of said gear. 4. Device according to claim 3, characterized in that the coding means comprises a two-channel detector arrangement, whereby the direction of rotation can be determined. 5. Device according to claim 3, characterized in that it further comprises a stop (460) on said gear, this stop cooperating with a fixed point (470) of the franking apparatus to determine a known value for the Print wheel, point from which other positions of the print wheel can be calculated from information provided by the coding means. 6. Device according to claim 1, characterized in that the motor (320) is a stepping motor. 7. Franking apparatus (10) of the type comprising a printing matrix (30) supporting signs and printing wheels for printing franking values, and a device for composing wheels according to the invention. 'any one of claims 1 to 6, characterized in that it comprises: - a multitude of printing wheels (310) each having respective gears (440); - a multitude of stepping motors (320) having respective shafts, each motor being associated respectively with one of the printing wheels (310); each shaft of the stepping motors supporting a pinion (410); - a multitude of transfer gears (430), each gear being engaged with the gears of the printing wheels; - a gear means (420) respectively connecting the transfer gears and the pinions to drive the printing wheels to a desired position; - the transfer gears having a number of teeth greater than that of the gears of the printing wheels, where a predetermined position of the gears of the printing wheels is associated with a multitude of positions of the respective transfer gears; - means for determining the shortest rotation path for the rotation of each transfer gear in order to place the print wheel in a desired position; and 5 10 15 20 25 30 35 40 45 50 55 60 65 9 17 CH 678 161 A5 a means for driving the stepping motor as necessary in order to rotate the transfer gear and consequently the printing wheels to the desired position. 8. Device according to claim 7, characterized in that it further comprises coding means (480) to allow the determination of the position of each print wheel. 9. Device according to claim 8, characterized in that the gear means (420) connected to both the transfer gears (430) and the pinions (410) comprises part of the coding means, the coding means further comprising detector channels which are blocked and released by rotation of the connecting gear means. 15 10. Device according to claim 9, characterized in that the detectors are two-channel detectors for providing information on the phase from which the direction of rotation can to be determined. 20 25 30 35 40 45 50 55 60 10