GB706898A - Improvements in or relating to postal franking machines - Google Patents

Abstract

706,898. Franking machines. TELEFONBAU UND NORMALZEIT GES. Sept. 9, 1952, No. 22604/52. Class 100 (2) A franking machine comprises a printing roller 18 for printing a franking stamp on matter to be franked, the drive of the printing roller being controllable by an electric control circuit having a main contactor in series with an auxiliary contactor 9 which is operable by the matter to be franked when fed through the machine to prepare the control circuit, the main contactor being operable at regular time intervals by a motor 3 for driving the printing roller, to open and close the circuit so as to print franking stamps at regular intervals on a strip of material fed through the machine. The motor 3 drives a conveyer 4 for the matter to be franked, a shaft 21 driving the roller 18 through a dog clutch 15, 20 and a main-contactor cam shaft 17 through reduction gearing 16. The shaft 17 carries cams 32, 33, 34 operating main-contactors 35, 36, 37 respectively. The clutch part 15 is continuously driven whilst the part 21 is spring- biased for operative connection but normally kept out of engagement by a lever 24 so that until operation of the lever 24 the roller 18 remains stationary. A subtracting counting mechanism 40 controlled by a cam 38 on the shaft 21 is provided and maintains a switch 43 closed until the desired number of franking operations has been completed. When it is desired to print on individual envelopes the envelopes are stacked on a table 5 removably mounted on the frame 1 of the machine and are fed to the conveyer 4, the main contactor switch 50 being set in the position shown in Fig. 3. The envelopes are detected by a feeler 26. The auxiliary contactor 9 comprises a mercury switch having a main contact 31 on an iron arm 29 and held out of engagement with the liquid contact 30 by a permanent magnet 28. Operation of the feeler 26 moves the magnet 28 out of range of the arm 29 and the switch makes contact thereby energizing an electromagnet 23 which in turn causes operation of the lever 24 so that the roller 18 makes a franking revolution. When it is desired to print on a strip of material the table 5 is replaced by a web roll holder 6. The switch 50 is set in a position so as to select one of the circuits passing through contacts 35, 36, 37 depending on the frequency at which a franking stamp is desired to be printed on the web. Since the web is continuous the feeler 26 is continually operated and the auxiliary contactor 9 remains closed. Energization of the electromagnet 23 therefore takes place under the control of the selected one of switches 35, 36, 37, operated by cams 32, 33, 34. Each time the roller 18 prints a franking stamp the web is severed on emerging from the machine by a cutter device 8 which is also controlled through linkage by the electromagnet 23. The counting device is set at the number of franking stamps required and when this number has been reduced to zero the switch 43 is opened thereby stopping any further printing operation.