US2683413A - Electrical control means for rotary franking machines - Google Patents

Description

W. MULLER July 13, 1954 ELECTRICAL CONTROL MEANS FOR ROTARYFRANKING MACHINES Filed Oct. gn, 1952 2 Sheets-Sheet 1 W. MULLER July 13, 1954 ELECTRICAL CONTROL MEANS FOR ROTARY FRANKING MACHINES 2 Sheets-Sheet 2 Filed Oct. 1'7, 1952 w W Nw Q mw o Patentecl July 13, 1954 ELECTRICAL CONTROL MEANS FOR- ROTARY FRANKING MACHINES Wilhelm Miiller, Frankfurt am Main, Germany,

assignor to Telefonbau und Normalzeit Gesellschaft mit beschrankter Haftung, Frankfurt am Main, Germany, a joint-stock company of Germany Application October 17, 1952, Serial No. 315,301

9 Claims.

The present invention relates to franking machines which are used for printing a stamp replacing an adhesive stamp on letters, postcards, or other matter to be forwarded by mail.

1 In one type of prior art franking machines a stamp is printed directly on the matter to be forwarded by mail. In another prior art franking machines stamps are being printed on a strip of paper or tape drawn from a storage roller whereupon, the strip or tape is subdivided by a cutting device of the machine into individual lengths usable for franking newspapers, periodical and the like. It has also been suggested to adapt franking machines for printing stamps directly on letters and the like mail for successive printing of stamps on tape. In one type of these last referred-to machines the end of a tape is being moved forward by a printing roller out of the initial printing position and fed to a cutting device which cut off the printed end from the tape, whereupon the unused end thereof is returned to the printing position. In an alternative arrangement, a length of tape to be printed is being cut off and the cut-off length then fed to the printing roller. has an automatic control of the printing roller responsive to the feed of the matter to be printed and can also be employed for printing on paper tape. In both arrangements, a guide for the paper tape, a feeding device therefor and a cutting device are combined to form a structural unit which can be added at will to the frame of the franking machine. With both arrangements it is however only possible to obtain the intended mode of operation by interfering with the driving mechanism of the franking machine and by adding auxiliary steps of operation.

It is an object of the invention to provide a simple franking machine which is capable of being used selectively for printing stamps either on individual matter to be forwarded by mail, such as letters, or postcards, or on paper strips or tape.

Another object of the invention is to provide a franking machine for such selective use without the necessity of interfering with the driving mechanism of the machine on change from one mode of use to the other.

A further object of the invention is to provide a franking machine for printing stamps on strips of paper and cutting the strips, wherein the strips are always fed through the machine in the same direction.

Still another object of the invention is to modify a franking machine with an automatic control of its printing roller responsive to the feed This type of franking machine of the matter to be printed in a simple manner in such a way that it is possible to feed a strip of paper drawn from a storage device into and through the machine without subdividing the strip, without changing the direction of the movement thereof, and with a constant but pre-settable speed, and thus to print successively spaced stamps on such strips.

These and other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of an embodiment of the invention, when read in conjunction with the appended drawings, which are given by way of example only and in which:

Fig. 1 is a perspective View of a franking machine embodying the invention;

Fig. 2 is a front elevational view of the same machine as shown in Fig. 1 and Fig. 3 is an electric circuit diagram of the machine of Figs. 1 and 2.

According to the invention, an electric main contactor operable by an electric motor for driving a printing roller at regular time intervals corresponding to the sequence of prints on a paper strip is provided in an electric control circuit for the printing roller in series with an auxiliary contactor which is kept closed by a paper strip While the strip is being fed through the machine, whereby to enable stamps to be successively printed on the strip, each print being effected by the closing of the main contactor. The auxiliary contactor operable by the paper strip only prepares the control circuit for the printing roller, while the main contactor operable by the electric motor closes the said control circuit at regular time intervals. The auxiliary contactor is kept closed only during the feed of the strip and thus breaks the control circuit when the feed of the strip is terminated. The auxiliary contactor also breaks the control circuit and thereby prevents a further operation of the printing roller when the paper strip becomes accidentally torn. The electrically controlled mechanism of the franking machine is inexpensive and may easily be added to an existing franking machine.

Preferably, a further contactor is provided in the electric control circuit and is controllable by a counting device for counting the number of stamps printed on the strip in such a manner that said further contactor is opened when a number of prints which is predetermined by the setting of the counting device have been effected.

In order to enable stamps to be printed on pieces of tape of different lengths, a plurality of main contactors may be provided which are operable by the electric motor at regular time intervals difierent for each contactor, one of the said main contactors being insertable at will into the electric control circuit for the printing roller. Preferably an electric change-over switch is provided in the control circuit for the printing roller which bridges the main contactor or contactors operable by the electric motor at regular time intervals and also the further contactor, if any, in its position for directly franking letters. In its other position or positions intended for printing stamps on paper tape which positions correspond to the number of main contactors this change-over switch inserts the main contactor or one of the main contactors, and also the further contactor, if any, into the electric control circuit;

The drawings show, a manually operable stamping device 2 removably attached to a base I of a franking machine. When the stamping device 2 has been detached, it may be removed from the frame I and may be used manually for printing stamps on any suitable object. For mechanically operating the stamping device 2 when attached to the base I of the franking machine, an electric motor 3 is provided which is likewise-mounted on the base I.

In front of the inlet of the franking machine a removable table 5 is provided for supporting letters or postcards to be franked. When it is intended to successively print stamps on a strip of paper or tape, the table 5 is replaced by a bracket 6 for a paper roll 1. At the outlet of the franking machine, a removable cutting device 8 is provided for cutting the stamped strip of paper at regular intervals. Between the inlet of the franking machine and thestamping device 2, a switching mechanism 9 is provided which is adapted tobe operated by the matter to be franked. The electric motor 3 drives one of a pair of conveyer rollers l l by means of a suitable gear, a conveyer belt 4 being placed around and being driven by said rollers. Counter-pressure rollers l3 press-against conveyer belt 4. The electric motor 3 also drives a first member l5 of a dog-clutch by means of a chain l4, and a camshaft IT by means of a reduction gear I6. Printing roller 13 of the stamping device 2 is mounted adjacent to conveyer belt 4. The printing roller !8 is operatively connected to a shaft 25 carrying a'second member of the dog-clutch by means of an intermediate gear ill. The second member of the dog-clutch is urged by a spring (not shown) in the direction towards the first member E5 of the dog-clutch, but is normally prevented from moving in this direction by a locking lever '24 controlled by an armature 22 of an electromagnet 23. The locking lever 24 bears-against a projection-25 of a disc keyed to the shaft 2i. Matter to be stamped and placed onto the conveyer belt 4 passes a tiltable lever 26 arranged in front of the stamping device 2. A permanent magnet 28 is arranged adjacent a mercury switch 21, and is mechanically tied to the tiltable lever 26. Within the mercury switch 2?, a solid contact member 3| is fixed to a resiliently supported iron arm-29 arranged opposite a cup 30 containing mercury, the solid contact member 3| being normally lifted out of the mercury in the cup 30 under the action of the permanent magnet 28 on the iron arm 23. When matter to be stamped and placed onto the conveyer belt 4 reaches the tiltable lever 25, the same rotates the permanent magnet 28 to such' an extent away from the mercury switch '21 that the solid contact member 3| drops into the mercury in thecup 30 owing to the weight of the iron arm 23, whereby the mercury switch 21 is closed. The cam-shaft ll carries three cams 32, 33 and 34, of which the cam 32 has one projection, the cam 33 has two projections arranged diametrically opposite to each other, and the cam 34' has three projections equally distributed along the periphery of the cam. Each of the cams 32, 33 and,34 cooperates with one of three contactors 35, 36 and 3'! formed by sets of contact springs controllable by the corresponding projection or projections of the cams. When shaft I! is rotated the projections on cams 32, 33'and 34 engage the contact springs of contacts 35, 36 and 3'! and efiect contact between them.

The shaft 2| carries a cam 38 acting on a rotatable lever 3'9'of'a subtracting counting device 40; A desired number of stamps to be printed may be predetermined by means of rotatable nobs 4'l provided on said counting device. The predetermined number of stamps appears behind the windows 42 of counting device 40. On each complete revolution of'the cam 38, the predetermined number' is reduced by one digit. The counting device 40 comprises a further contactor 43 which is kept closed as long as the number shown by the counting device 40 is difierent from zero, and the further contactor 43 is opened when the counting device is down to and indicates zero.

A two-wire line 46 for energizing theelectric motor 3 terminates in a plug45' and includes a double-pole switch 41 andthe exciting or energizing coil 48 of the electromagnet 23 and the switching mechanism 3 forming an auxiliary contactor arranged inseries with the exciting coil 43. The above circuit includes four'terminals 5i, 52, 53 and 54 of a two-stage change-over switch 50. Mechanism 9 is either directly connected to the terminal 5t of switch 50* or across'one of the main contactors 35; 3B; 31, controlled by the cams 32, 33, and 34to one of'the terminals 52, 53, and 54 of switch 50. Furthermore, the circuit includesterminals 55, 55, 5'Iand 58 of the second stage of change-over switch 55. The portion of switch 50 shown at the right of Fig. 3 may, either be directly connected to the terminal 55, or across the further contactor 43 to the terminals 53, 51' and 58; The second stage of the change-over switch 50'shown at the left of Fig. 3 isconnected over a fuse 59 to the double-pole switch 41. The driving electric motor 3 is shunted across the two wires of the energizing line or, to bemorespecific, is branched off between one pole of the double-pole switch 4'! and the exciting or energizing coil48of theelectromagnet 23. Motor 3 is connected totheswitching lever of the change-over switch 50-which co-operates with I the terminals 5i to 54. When the two switching levers of the change-over switch 50 are placed on terminals 5! and 55, respectively, as shown in Fig. 3, the" contactors 35, 35 and31controlledrespectively by the cams 32, 33 and 34, as well asthe further contactor 43 are bridged-or shunted out. Change-over switch 53- is placed in this positi'on'which will briefly be referred to by the abbreviatedterm letter when it is intended to print directly onletters'or postcards. However, when" the switching levers of the change-over switch Ell-are positioned on one of the pairs ofterminals 52; 56; or 53', 51-; or 54, 58, then, in each caseyone of the contactors 35, 36, and 3! controlled, respectively, by the'cams 32; 33 and 34, andalso the further contactor 43, controlled by the-counting device '40-, are efiective.

Since the cams 32, 33 and 34 are driven by the electric motor 3 with a constant speed, the contactors 35, 3S, and 3'! are periodically closed and opened but each at different time intervals. Now, depending on the position of the change-over switch 59, that is to say depending on which one of the contactors 35, 36 and 37 has been rendered eifective in each case, the electric control circuit is periodically closed and opened but the time intervals are diii'erent for each of the three contactors. The terminals 52, 53 and 54; and 56, 51 and 58 are rendered effective when it is intended to print stamps onto a paper strip or tape. The corresponding positions in which the change-over switch 58 is placed when it is intended to print on a paper will be referred to by the abbreviation strip.

When the double-pole switch 4.1 is closed after insertion of the plug 45 into a corresponding socket of the main supply, the electric motor 3 is started and drives the conveyer belt 4 as well as the chain Hi. When the change-over switch 55 is in position letter, the electric circuit for the electromagnet 23 operating the dog-clutch is closed each time a letter passes the tiltable lever 26 of the switching mechanism 9, causing the locking lever 24 to release the printing roller l8 while it is coupled to the electric motor 3 by the dog-clutch to perform one revolution and to print a stamp on to the letter carried through the machine by the conveyer belt 4. The time interval between the operation of the tiltable lever 26 by a letter and the release of the iron arm 29 is so selected that the letter to be franked reaches the printing roller l8 during this interval. Each franking print is counted by the counting device 40 of the stamping device 2. When the changeover switch 55 is brought into one of the positions strip, then the auxiliary contactor formed by the switching mechanism 9 remains closed during the passage of a strip through the franking machine inserted into it. The electric circuit prepared by switching mechanism 9 is closed by one of the main contactors 35, 36 and 3 7 operated by the electric motor 3 at regular intervals of time whereby on each closing of the respective contactor the electromagnetically operated dogclutch causes one single revolution of the printing drum which performs one print on the strip. The number of prints on the strip is being counted by the counting device 40. The cutting device 3 arranged at the outlet of the franking machine and operated by the armature 22 of the electromagnet 23 cuts ofi a desired length of the strip after each print. When a predetermined number of prints have been made on a tape, the electric control circuit is interrupted by the further contactor 43 of the counting device 40. The cutting device 8 comprises a sleeve 69 fixed on a frame or casing of the franking machine. Sleeve 68 has slots 6| and 62 of different width at the front and the rear, respectively. A roller 63 is rotatably mounted within the sleeve 6:] and has a conical slot 64 extending through it. The limiting edges of the slot 54 at the narrowest region thereof operate as cutting edges. In its initial position, the conical slot 85 registers with the slot 52 at the rear of the sleeve 60. The roller 63 is tied mechanically to the armature 22 of the electromagnet 23 in such a manner that each time the armature 22 is attracted, the roller 63 performs a limited rotation. A paper strip 65 threaded through the slots of the sleeve 60 and of the roller 63 is cut off by the rotational movement of the roller 63 caused on each excitation or energization of the electromagnet 23. After the cutting process has been terminated, the conical slot 64 of the roller 63 guides the paper accumulated therein during a cutting process towards the slot 52 of the sleeve fill. The cutting device 8 as well as the table 5 and the bracket 6 for holding the paper roll 1 may be connected to the frame or casing of the franking machine by a clamp lock which is easily releasable.

The spacing of successive prints on the strip or tape depends on the number of projections on the cams 32, 33, 34 for operating the main contactors 85, 3t, 37, respectively, which are rendered efiective in the strip positions of the change-over switch 50. When the number of projections is increased, the electromagnet 23 operates the dogclutch at correspondingly shorter time intervals, whereby the strip or tape running through the machine is provided with stamp prints at shorter distances. According to the desired length of the cut-off pieces of the strip, the cams 32, 33 and 34 may be exchangeable against others having greater numbers of projections. If the paper strip should tear during the operation of the device, the switching mechanism 9 operating the mercury switch 21 relapses, whereby the solid contact member 3!, owing to the iron arm 29 being now attracted by the permanent magnet 28, is lifted from the mercury cup 30 opening the mercury switch. Thereby the electromagnet 23 for operating'the dog-clutch is disconnected so that the printing roller i8 is rendered inoperative. The printed lengths cut off from the paper strip or tape may subsequently be fed through an addressing machine providing the lengths of the paper strip with addresses.

I claim:

1. A franking machine comprising means for feeding matter to be franked through said machine, a printing roller for printing a franking stamp on such matter, a drive, a clutch for coupling said drive to said printing roller, an electric control circuit, means in said circuit for operating said clutch to cause said printing roller to perform a revolution when said control circuit is closed, an electric main contactor in said circuit, said main contactor being operable by said drive to make and break said control circuit at regular intervals of time to cause the printing roller to print franking stamps at regular distances on tape fed through said machine, and an electric auxiliary contactor arranged in said control circuit in series with said main contactor, and operable by the matter to be printed while fed through said machine to prevent continued printing when the feed of the tape is interrupted, contactor making and breaking the control circuit at regular time intervals to cause the printing roller to print franking stamps at regular distances on to the strip, the auxiliary contact preventing the printing when the feed of the strip is interrupted.

2. A franking machine as claimed in claim 1, wherein a plurality of main contactors are provided in the electric control circuit, the said main contactors being all operable by the drive to make and break said control circuit at regular time intervals of different lengths for difierent main contactors, means being provided for alternatively rendering one of the main contactors effective, whereby to alter the distances between stamps printed on a strip in dependence on the main contactor rendered efiective.

3. A franking machine as claimed in claim 2, wherein a plurality of cams are inserted between accents andcomprising' a reduction gear between the drive and the cams. V

5. A-franl ing machine as claimed in claim 2, and comprising a change over switch in the electrio control circuit which in one position bridges the main contactors-and the further contactor to render'the same ineffective for printing stamps on the separate matters, and in each of its other positions, the number of which corersponds to the plurality of main contactors, renders one of the main contactors and the further contactor effec-' tive'for printing stamps on to-a' strip of material.

6. A franking machine as claimed in claim 2,

and comprising a frame housing the drive, the

printing roller forming part of a manually operable stamping device releasably coupled to said drive, the electric control circuitforsaid drive comprising the auxiliary contactor, the plurality of main contactors and the further contactor.

7. A postage printing machine comprising a tape feeding device, a printing roller suppliedwith tape from said feeding device, motor means for operating said printing roller, a clutch for selectively coupling and uncoupling said motor means and said printing roller; an electric control circuit, a magnetic means energizable by the flow of current in said circuit to operate said clutch to couple said motor means and said print ing roller, a first switching device arranged in said circuit operable by said motor means to effect periodic opening and closing operations of said circuit tocause periodic operation of said printing roller to make a plurality of equidistant imprints on said tape, a second switching device arranged in said circuit in series with said first switching device, and means under the control of said tape when fed from said feeding device to said printing roller for controlling said second switching device to interrupt said circuit to stop the operation of said printing roller upon interruption of the feed of said tape.

8. A postage printing machine comprising a tape feeding device, a printing roller supplied with tape from said feeding device, motor means for operating said printing roller, an automatic clutch for selectively coupling and uncoupling said motor means and said printing roller, an electric control circuit, an electroinagnet energizable by the flow of current in said circuit, a linkage operated by said electromagnet to operate said automatic clutch to couple said motor means and said printing roller, a first switching device arranged in said circuit and operable by said motor means, said first switching device comprising a plurality of pairs of contacts each operabie to effect a different number of periodic opening and closing operations of said circuit in a given interval of time to cause periodic operation of said printing roller to make a plurality of equidistant imprints on said tape, a plurality of different cam means operated by said motor means each effecting relative movement of one of said plurality of pairs of contacts to cause said periodic opening and closing operations of said circuit, a second switching device arranged in said circuit in series with said first switching device, and means under the control 01'' said tape when fed from said feeding device to said printing roller for controlling said second switching device to interrupt said circuit to stop the operation of said printing roller upon interruption of the feed of said tape.

9. A iranking machine as claimed in claim 1 comprising a subtracting counting device adapted to be manually pre-set on a pre-determined number, means controlled in accordance with the rotary motion of said printing roiler to subtract the number of stamps printed by said printing roller from the predeterminednumber manually pre-set in said, counting device, a further contactor arranged in the electric control circuit for maintaining said circuit closed as long as the difference determined by said counting device difiers from zero, and means controlled by said counting device for opening said further contactor on completion of the pre-set number of prints to break said control circuit to preclude continued printing by said printing rolier upon completion of the pre-set number of prints.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,238,359 Copeland et a1 Apr. 5, 1941 2,350,703 Ryan et a1 June 6, 1944 2,518,011 Hoppe Aug. 8, 1950

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