| 摘要 |
<p>1534742 Packaging apparatus HAYSSEN Mfg CO 6 Oct 1976 [7 Oct 1975] 41458/76 Heading G1W Packaging apparatus comprises a plurality of means each adapted to measure out a batch of a product, means for delivering the batch from any one of the measuring means to a package, and means for marking on a package a code designating the particular measuring means which measured out the batch in the pocket. In the embodiment, the measuring means are constituted by four weighing scales S1 to S4, but could alternatively be volumetric or counting devices. The machine includes a mandrel 9 and a seam sealer 14 for forming a packaging tube T from a roll R of heat sealable plastics film W. The tube is formed into packets by a transverse sealing and severing device which comprises a pair of seal bars 17a 17b mounted on a vertically reciprocable carriage 15. In use the carriage 15 travels to its upper limit, the bars 17a, 17b grip the tube to seal it and move downwardly to advance the tube by one package length, and the bars release the tube. Each seal S1-S4 is emptied in turn into a funnel 19 to fill a package. The marking means 5 is carried by the seal bars 17a, 17b such that the code mark is applied when a transverse seal is formed. Each code mark is carried by a plunger 25a-d which is slidable in a printing head 23 against the bias of a spring 31 to imprint a code mark on the package. A pneumatic actuator 27 for the plungers is fixed relative to bar 17a, and the printing head 23 is indexable to bring each plunger in turn into a printing position in front of the actuator. To effect indexing of the printing head, a pair of pneumatic double acting rams 41 and 43 are provided, the cylinders of the rams abutting each other, the piston 47 of ram 41 being fixed relative to bar 17a, and the piston 48 of ram 43 being connected to a bar 55 which is slidable relative to bar 17a and which carries the printing head 23. The stroke of ram 41 is equal to the spacing of the plungers 25a-d and the stroke of ram 43 is twice that of ram 41 so that selective operation of the rams allows any plunger to be positioned in front of actuator 27. The machine is controlled by means of cam operated switches, the cams being driven in step with the packaging cycle, and the control circuits shown in Figs. 7 and 8. Scale Sl includes means (not shown) to produce a signal when a predetermined weight has been depositied on its tray T, and the signal energizes relay CR1 to close its contacts R1a, R1b. Closure of contacts R1b allows scale S1 to be emptied when switch LS1 is tripped, and closure of contacts R1a allows air valve AV2 to be operated when switches LS2 and LS6 are tripped to actuate bars 17a, 17b to grip the tube. The other scales S2-4 are provided with similar relay circuits, and if a particular scale has not reached the predetermined weight at the appropriate time in the cycle, the bars 17a, 17b are not actuated to grip the tube and the scale is not permitted to empty. Switch LS7 closes as switch LS6 opens at the end of the downward movement of the carriage 15 and operates air valve AV3 to effect opening of bars 17a, 17b. Closing of the bars 17a, 17b actuates a limit switch LS8 which via a relay CR5 and together with switch LS10 actuates air valve AV4 to operate the actuator 27. The indexing rams are controlled by switches LS10, LS11 and air valves AV5, AV6.</p> |
