US 3520177 A
Description (OCR text may contain errors)
B. HEITMANN ET AL APPARATUS FOR TESTING AND CLASSIFYING CIGARETTES July 14, 1970 OR THE LIKE 3 Sheets-Sheet 1 Filed Jan. 17, 1968 "/N VENTORS:
ATTORNEY July 14, 1970 B. HEITMANN ETAL 3,520,177
APPARATUS FOR TESTING AND CLASSIFYING CIGARETIES Filed Jan. 1.7, 1968 Fig.2
OR THE LIKE 3 Sheets-Sheet 2 Fig.4
y 1970 B. HEITMANN ET AL 3,520,177
APPARATUS FOR TESTING AND CLASSIFYING CIGARETTES OR THE 5. Sheets-Sheet 5 LIKE Filed Jan. 17. 1968 United States Patent 0 3,520,177 APPARATUS FZPR TESTING AND CLASSIFYING CIGARETTES OR THE LIKE Bob Heitmann, Hamburg, Hans J. Grasse, Wentorf,
Giinter Schubert, Reinbek, and Fritz Bodner, Hamburg-Lohbrugge, Germany, assignors to Hanni- Werke Korber & Co. KG., Hamburg, Germany Filed Jan. 17, 1968, Ser. No. 698,522 Claims priority, application Great Britain, Feb. 10, 1967, 6,405/ 67 Int. Cl. G01m 3/04 U.S. Cl. 7345.1 12 Claims ABSTRACT OF THE DISCLOSURE A rotary testing drum for cigarettes is provided with axially parallel flutes which receive cigarettes at a first station and advance them past a testing station where the cigarettes are tested for the presence of defects, thereupon past an ejection station where a defective cigarette is expelled from its flute by compressed air, and finally past a transfer station at which the satisfactory cigarettes leave their respective flutes. The drum is provided with suction ports communicating with the flutes and with orifices adjacent to each flute. Satisfactory cigarettes are held by suction during travel past the ejecting station. The testing unit which tests cigarettes during travel past the testing station sends signals to an ejecting device which includes a stationary conduit for compressed air and a regulating valve in the conduit. The valve opens in response to a signal and the conduit then admits compressed air into orifices adjacent to that flue which accommodates a defective cigarette or directly into the ports in such flute to effect expulsion of defective cigarettes at the ejecting station. In order to facilitate expulsion of defective cigarettes by compressed air, suction ports in a flute which accommodates a defective cigarette can be automatically connected with the aforementioned conduit during travel past the ejecting station so that, when the conduit admits compressed air to a set of orifices, it also admits air to the corresponding suction ports to raise the pressure therein and to reduce the force with which the defective cigarette is held in its flute. The orifices adjacent to a flute for a defective article can be connected with the corresponding suction ports by way of a flow restriction passage or orifice provided in a control ring which regulates the evaluation of air from suction ports and the admission of air from the conduit into the orifices in response to rotation of the drum.
CROSS-REFERENCE TO RELATED APPLICATION The apparatus of our present invention constitutes an improvement over and a further development of testing apparatus disclosed in the copending application Ser. No. 431,355, now US. Pat. No. 3,412,856, filed by Albert Esenwein on Feb. 9, 1965 and assigned to the same assignee.
BACKGROUND OF THE INVENTION The present invention relates to apparatus for testing and classifying cigarettes, cigarillos, or cigars with or without filters and of unit or multiple unit-length, filter rod sections and analogous rod shaped articles wherein an open-ended tubular wrapper surrounds a filler of airpermeable material. More particularly, the invention relates to improvements in apparatus wherein the articles are tested by means of air or another fluid while traveling sideways in the flutes of a conveyor from a receiving station, past a testing station and thereupon past an ejecting ice station where the defective articles are removed from their flutes.
It is already known to hold cigarettes or like rod shaped articles by suction while the articles travel sideways past a testing station where the wrappers and/or fillers of such articles are tested by means of air. Ejection of defective articles is effected by jets of compressed air which expel defective articles from their holders on the conveyor in response to signals received from the testing unit. A serious drawback of many presently known testing apparatus is that it requires too much time to open the valve which admits compressed air, especially if such apparatus are employed for testing of cigarettes or filter cigarettes issuing from a high-speed cigarette or filter cigarette machine. The ejecting devices of highspeed testing apparatus must produce very strong jets of compressed air in order to insure that a defective article is invariably expelled in a predetermined zone of the path along which the articles travel past and beyond the testing station. The flow of such strong jets of compressed air must be regulated by relatively large valves whose inertia is high, Le, a large and bulky valve requires more time for opening and/ or closing than a smaller valve of lightweight design.
SUMMARY OF THE INVENTION It is an object of our invention to provide a novel and improved testing apparatus wherein defective articles can be readily and rapidly segregated from satisfactory articles while such articles travel at a high speed beyond a testing station where the articles are tested for the integrity of their components.
Another object of the invention is to provide a testing apparatus wherein the defective articles can be segregated by relatively weak blasts or jets of air or another suitable gaseous fluid.
A further object of the invention is to provide a testing apparatus wherein the force which retains the articles on the conveyor which transports them past and beyond a testing station can be reduced automatically so that the defective articles offer little resistance to expulsion and resulting segregation from satisfactory articles.
The improved testing and classifying apparatus comprises a conveyor which preferably includes a drum rotatable about a fixed axis and having axially parallel holders provided with flutes for a succession of rod shaped articles. The articles travel past a testing station and thereupon past an ejecting station for defective articles. Those articles which are satisfactory are held by suction during travel past the ejecting station. A testing unit which tests articles during travel toward the ejecting station controls the operation of an ejecting means which includes a stationary conduit connectable with a source of compressed gas and a regulating valve which opens in response to signals from the testing unit to admit compressed gas into the conduit and into orifices provided in the conveyor adjacent to the flutes for a defective article. In order to facilitate expulsion of defective articles from their flutes, the conduit is automatically connected with suction ports which normally hold the articles in their flutes so that the pressure in the ports for a defective article rises and relatively Weak jets of air issuing from the orifices can readily dislodge a defective article. The suction reducing means preferably resembles a flow restricting orifice provided in a control means which regulates the suction in the aforementioned ports and the admission of compressed gas from the conduit into the orifices in response to movement of holders.
It is also possible to admit compressed gas directly into the suction ports and to omit the orifices.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved testing apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a conveyor in a testing apparatus which embodies one form of our invention;
FIG. 2 is a fragmentary axial sectional view of the apparatus, substantially as seen in the direction of arrows from the line IIII of FIG. 3;
FIG. 3 is a transverse sectional view as seen in the direction of arrows from the line IIIIII of FIG. 2; and
FIG. 4 is a diagrammatic side clevational view of a second testing apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus of our invention is utilized for testing of cigarettes, filter cigarettes, filter rod sections, cigarillos or like rod-shaped articles wherein an open-ended tubular wrapper surrounds an air-permeable filler. The apparatus comprises a conveyor 1 which serves to advance a series of articles sideways from a receiving station, past a testing station, thereupon past an ejecting station for defective articles and finally past a transfer station where the satisfactory articles are taken off for transport to one or more additional processing stations.
In the illustrated embodiment, the conveyor 1 includes a hollow drum 3 which is rotatable about the axis of a fixed shaft 2. The upper end of the shaft 2, as viewed in FIG. 1, is mounted in a supporting frame (not shown). The drum 3 comprises a cylindrical portion 4 (hereinafter called cylinder for short) which is rigid with two axially spaced radial extensions or flanges 5 and 6. The latter flange 6 is mounted on and is affixed to a tubular extension 19 of the cylinder 4 at that end of the cylinder which is remote from the aforementioned frame. The flange 6 is surrounded by an annular synchronizing cam 35 having equidistant radial metallic projections or lobes 36, and that axial end of the extension 19 which is remotest from the flange 5 is adjacent to but spaced from a ring 33.
The exterior of the cylinder 4 is provided with sets of axially parallel holders 8 having grooves or flutes 7 which accommodate the articles during travel with the drum 3. The grooves 7 are equidistant from each other and are parallel to the axis of the shaft 2. The cylinder 4 has an internal annular shoulder 14 which is surrounded by the extension 19 and this cylinder is provided with pairs of axially parallel blind bores or channels 11, 13 extending toward but short of the inner end face of the flange 5. Each pair of channels 11, 13 is located in a radial plane of the drum 3, such plane also including one set of grooves 7. The centers of channels 11, 13 are located on two circles whose centers are located on the axis of the shaft 2. Each channel 11 communicates with radially outwardly extending suction ducts or ports 9 which terminate in the grooves 7 of the associated set of holders 8 and the channels 11 can be connected to a suction generating device 41a to hold by suction articles in the associated grooves 7 while such articles travel from the receiving station and beyond the testing station. Radially outwardly extending orifices 12 communicate with the channels 13 and terminate in the periphery of the cylinder 4 between the corresponding grooves 7. The orifices 12 are preferably defined by small-diameter tubes which are inserted into the cylinder 4 and extend across the associated suction channels 11. The channels 13 can be connected to a source 77a of compressed gas, preferably air, to effect expulsion or ejection of articles from the corresponding grooves 7. The external diameters of tubes which form the orifices 12 are smaller than the diameters of suction channels 11.
The inner end face 15 of the flange 5 is formed with a set of axially parallel blind bores 17 each of which registers with the grooves 7 of one set of holders 8, and each bore 17 communicates with a radially outwardly extending bore 18 which terminates in the smooth peripheral surface 16 of the flange 5. The bores 17, 18 serve to convey a testing fluid.
A ring-shaped distancing element or spacer 21 is installed on the extension 19 between the flange 6 and an external annular shoulder of the cylinder 4. The flange 6 is of U-shaped cross-sectional outline and comprises two radially outwardly extending portions or arms at the axial ends of a ring-shaped web which surrounds the extension 19 of the cylinder '4. The arms of the flange 6 are formed with axially parallel bores or passages 22 each of which registers with one of the blind bores 17 in the flange 5, and each bore 22 comprises three sections of different diameter (see particularly FIG. 2). The bores or passages 22 accommodate nozzles 23 one of which is shown in greater detail in FIG. 2 and which serve to clamp the articles against the flange 5 and to convey testing air. The aforementioner ring 33 has bores or passages 32 each of which registers with one of the passages 22, and each passage 22 is inwardly adjacent to an outer passage or bore 24 in the arms of the flange 6. Each bore 24 accommodates an axially reciprocable shifter pin 25. The number of lobes 36 on the synchronizing cam 35 equals the number of sets of holders 8, and all of these lobes are located in a common plane which is normal to the axis of the shaft 2. The cam 35 is elongated in the axial direction of the shaft 2 and is provided with a radially outwardly extending flange 37 remote from the lobes 36 and located at that end of the cam which faces away from the cylinder 4. That end face of the flange 37 which faces away from the lobes 36 is provided with a group of concentric ring-shaped grooves 38-.
FIG. 2 is a fragmentary axial sectional view of the drum 3 and shaft 2 and illustrates some of the heretofore described parts including the cylinder 4 with extension 19, channels 11, 13 and shoulder 14, flange 6, cam 35, ring 33, spacer 21, and a shifter pin 25. The free end portion of the shaft 2 (i.e., that end portion which is remote from the aforementioned frame) is surrounded by a sleeve 43 which is axed thereto by a bolt, screw or like fastener 43a. The sleeve 43 is bolted to a carrier 48 for an electromagnetically operated regulating valve 49 and a testing unit 51. The carrier 48 is further connected with a sleeve-like support 52 by Way if a key 53. The support 52 has a cylindrical extension 54 which projects toward the cylinder 4 and is accurately fitted onto the sleeve 43. This support 52 is surrounded by a ring-shaped distancing element or spacer 78 and by a flange 79. The spacer 78 is interposed between an external shoulder of the support 52 and the flange 79.
The extension 54 of the support 52 is surrounded by a non-rotatable control ring 55 which regulates the flow of air. Springs 55a installed in blind bores of the support 52 bias the control ring 55 axially toward the shoulder 14 of the cylinder 4. A compressed air conduit 77 is mounted in the support 52 and its discharge end (i.e., the left-hand end, as viewed in FIG. 2) can register with successive pressure channels 13 of the cylinder 4. The discharge end of the conduit 77 extends into a bore of the control ring 55 and the latter is movable axially of this conduit. The right-hand end of the conduit 77 is connected with the source 77a of compressed air, e.g., a compressor. The valve 49 is mounted in the conduit 77 immediately or closely adjacent to the point where the conduit enters the support 52. The exact configuration and function of the control ring 55 will be described with reference to FIG. 3. The ejecting device for defective articles includes the valve 49 and the conduit 77 with source 77a.
The left-hand end face of the flange 79 on the support 52 has ring-shaped ribs 81 which extend into the grooves 38 of the flange 37 on the synchronizing cam 35. The ribs 81 are of rectangular cross-sectional outline. An annular recess provided in the flange 79 inwardly of the ribs 81 accommodates a ring-shaped shifter cam 82 having an end face tracked by roller followers 27 mounted in bifurcated end portions 26 of shifter pins 25. Each pin 25 further carries a shifter fork 28 located between the arms of the flange 6. A helical spring 29 which is inserted between one arm of the flange 6 and shifter fork 28 biases the pin 25 in a direction to the right, as viewed in FIG. 2, to maintain the follower 27 in engagement with the face of the cam 82. The prongs of the fork 28 straddle a reduced-diameter portion of the nozzle 23, and this fork has some freedom of axial movement With reference to the nozzle. A helical spring 31 operates between the prongs of the fork 28 and a shoulder of the nozzle 23 to bias the latter in a direction to the left, as viewed in FIG. 2. The nozzle 23 has an axial passage 34.
The flange 79 on the support 52 has an annular recess 83 which accommodates a second control ring 84. This ring is movable axially but cannot turn with reference to the flange 79. The latter carries a radially inwardly extending guide pin 85 projecting into an axially parallel notch '86 of the control ring 84. A conduit 91 for testing air is connected with the control ring 84 to register at certain times with the bores 32 in the ring 33. The conduit 91 extends through a bore in the flange 79 and is connected with the testing unit 51. A slide ring 87 is affixed to that end face of the control ring 84 which faces the cylinder '4, and this slide ring is biased by springs (not shown) against the ring 33. The just mentioned springs operate between the control ring 84 and flange 79; the latter has recesses which receive portions of such springs in a manner similar to that shown for the spring 55a.
The testing unit 51 comprises a venturi 92 which is installed in the conduit 91 and whose throat is provided with a radial duct 93 conveying testing air to a chamber 94 which accommodates a diaphragm 95 constituting the movable electrode of a capacitor. The capacitance of the capacitor changes as a. function of changes in air pressure in the venturi 92 and this capacitor is connected in an oscillator circuit in a manner as disclosed in the aforementioned Esenwein application. The oscillator circuit is connected with a rectifier, a preamplifier, a signal storing device and finally with the regulating valve 49. The just mentioned elements of the electric circuitry of the testing device 51 are denoted cumulatively by the numeral 96.
Referring now to FIG. 3, the shaft 2 has an axially parallel suction bore 41 which is connected with a suction generating device 41a (FIG. 1), and an axially parallel pressure bore 42. The bore 41 communicates with a radial cutout 44 of the shaft 2 and this cutout communicates with a cutout 47 of the sleeve 43. The cutout 47 communicates with radial bores 59, 61 and 62 provided in the cylindrical extension 54 of the support 52. The bore 42 communicates with a radial port 45 of the shaft 2, and this port 45 communicates with a radial bore 64 of the extension 54 by way of a cutout 46 in sleeve 43. The control ring 55 is provided with an inner slit shaped opening 76 located at the same distance from the axis of shaft 2 as the channels 13, and with a group of outer slit-shaped openings 65, 66, 69, 67, 68 located at the same distance from the axis of shaft 2 as the channels 11. These openings are machined into that face of the control ring 55 which faces the cylinder 4. The opening 76 serves to admit compressed air to pressure channels 13 and the openings 65, 66, 69, 67 can evacuate air from the channels 11 and ports 9 of the cylinder 4. The opening 65 is located at the two oclock position, as viewed in FIG. 3, and is connected with a radial bore 58 which communicates with the aforementioned bore 62. The bore 58 is provided in the ring 55. The opening 65 is located in the region of the receiving station, i.e., where a feed admits articles into successive sets of aligned grooves 7.
A fresh air admitting bore 72 machined into the control ring 55 is angularly spaced from the opening 65 by a distance exceeding slightly the diameter of a channel 11. The second outer opening 66 begins at the five oclock position and serves to convey suction air which holds the articles during travel past the testing station. This opening 66 communicates with a radial bore 57 of the control ring 55 and with the bore 61 in the extension 54 of the sleeve 52. The opening 66 is immediately followed by the opening 69 and the latter is immediately followed by the opening 67 which terminates at the eight oclock position. The opening 67 communicates with a radial bore 56 of the ring 55 and with the bore 59 in the extension 54. A first flow restricting orifice 73 connects the openings 66, 69, and a second flow restricting orifice 74 connects the opening 69 with the elongated opening 67. A third flow restricting orifice 75 connects the opening 69 with the inner opening 76 of the control ring 55. Air conveyed through the opening 76 serves to eject articles from their respective sets of grooves 7. The length of openings 69 and 76 (as considered in the circumferential direction of the control ring 55) respectively equals the distance between two adjoining channels 11 or 13 minus the diameter of a channel 11 or 13. A further fresh air conveying opening 71 which resembles a circular bore is provided in the control ring 55 in circumferential alignment with the openings 65, 66, 69, 67 and 68. The distance between the left-hand end of the opening 67 and opening 71 exceeds slightly the diameter of a channel 11. The opening 68 is provided downstream of the delivery or transfer station to admit compressed air to channels 11 in order to expel impurities from the ports 9 and grooves 7. The opening 68 communicates with a radial bore 63 of the ring 55 and the radial bore 63 communicates with the radial bore 64 in the extension 54.
The opening 76 is in communication with the compressed air conduit 77 shown in FIG. '2. In the region between the openings 71 and 65, the slide ring 87 is provided with a control slot 88 whose length equals the distance between two adjoining bores 32 and which communicates with one or two bores 32.
The second control ring 84 has a control slot 89 (FIG. 2) at that side which is adjacent to the slide ring 87. The dimensions of the control slots 88, 89 are the same and there slots are in registry, as seen in the circumferential direction of the drum 3. The control slot 89 is in communication with the conduit 91 for testing air.
A stationary contactless initiator or signal generator 97 is immediately adjacent to the path of lobes 36 on the synchronizing cam 35; this initiator contains an induction coil 103 and is connected with the signal storing device in the electric circuit 96 of the testing unit 51 by way of a conductor 104.
A stationary shoe 98 is in sliding contact with the smooth peripheral surface 16 of the flange 5 and serves to convey testing air. In the region adjacent to the control slot 88, the shoe 98 is provided with a slot 99 which communicates with a channel 101 and by way of this channel With a supply conduit 102 for testing air. The latter is connected with a suitable source of testing air, not shown in FIGS. 1-3.
Arcuate retaining shields 107 extend along the periphery of the drum 3 from the opening 65 to the opening 66 to mechanically hold the articles in the respective grooves 7. Additional retaining shields 108 are provided between the opening 67 and the point of removal of satisfactory articles from the drum 3.
The drum 3 is rotated by a gear (not shown) which is affixed to the flange 5 and turns in a clockwise direction, as viewed in FIG. 1 or 3.
The suction openings 65, 66 and 67 are main suction openings because they are in direct communication with bore 41 by way of bores 58, 57, 56, bores 62, 61, 59 and cutouts 44, 47. The opening 69 is an auxiliary opening because it is connected with bore 41 indirectly, i.e., by way of orifices 73, 74- and main openings 66, 67.
The operation is as follows:
Articles are fed into successive groups or sets of grooves 7 in the region of the suction opening 65 shown in FIG. 3. Each such article is held by suction air drawn through the ducts 9, channel 11, opening 65, bore 58, bore 62, cutout 47, cutout 44 and bore 41. The article is thereupon engaged by the stationary retaining shields 107. Once a freshly transferred article reaches the region of the fresh air admitting bore 72, suction in the corresponding ducts 9 decreases because the associated channel 11 communicates with the bore 72 as the drum 3 continues to turn in a clockwise direction, as viewed in FIG. 3. However, the article cannot leave its groove 7 because it is held by the shields 107. The face of the cam 82 is configurated in such a way that it causes a roller follower 27 traveling past the bore 72 to move toward the cylinder 4 and to thus displace the pin 25 and fork 28 against the opposition of the corresponding spring 29 (see FIG. 2). The fork 28 displaces the nozzle 23 by way of the spring 31, Le, the nozzle is shifted in a direction toward the flange 5. Such axial movement of the nozzle 23 is terminated When the left-hand end of an article received in the grooves 7 registering with the nozzle 23 shown in FIG. 2 reaches the inner end face 15 of the flange 5, namely, when one end of the article overlies the open end of the registering bore 17 in the flange 5. The fork 28 continues to move to the left, as viewed in FIG. 2, so that the spring 31 is compressed and biases the nozzle 23 against the adjoining end of the article. The spring 31 compensates for eventual differences in the length of articles which are admitted seriatim into successive sets of grooves 7 on the cylinder 4.
The drum 3 continues to rotate in a clockwise direction whereby the corresponding radial bore 18 of the flange 5 reaches the slot 99 in the stationary shoe 98 which bears against the peripheral surface 16 of the flange 5. The source of testing air then admits air by way of supply conduit -2, channel 101, slot 99, radial bore 18, blind bore .17, axially through the filler of the article, bore 34 of the corresponding nozzle 23, bore 32 of the ring 33, control slot 88 of the slide ring 87, control slot 89 in the second control ring 84, conduit 91 and venturi 92 of the testing unit 51. Some testing air escapes through the pores of the wrapper on the tested article. If the article is defective, for example, because its Wrapper has developed a leak due to a faulty seal between the overlapping edges of the wrapper material or due to a tear in such wrapper material, the amount of air escaping through the wrapper exceeds a predetermined minimum amount which is indicative of satisfactory articles. The testing unit 51 then receives less air than when the tested article is satisfactory. The pressure of air flowing through the venturi 92 of the testing unit 51 is measured in the chamber 94 which receives air through the duct 93, and the nature, length and/or intensity of impulses produced by the circuit 96 of the unit 51 is a function of the pressure of air flowing through the venturi 92. The initiator 97 cooperates with the lobes 36 of the rotating synchronizing cam 35 to produce synchronizing signals of a length corresponding to the interval during which the next-following set of grooves 7 occupies the position previously occupied by the preceding set of grooves. The initiator 97 generates such signals in response to travel of lobes 36 past the coil 103, and the resulting signals are converted into steeply rising impulses.
When a bore 32 of the ring 33 moves beyond the control slot 88 of the slide ring 87, the correspondingarticle is held in the associated grooves 7 by suction air drawn through the opening 66. At the same time, the face of the cam 82 allows the corresponding spring 29 to expand and to push the fork 28 in a direction to the right, as viewed in FIG. 2. The fork 28 moves the nozzle 23 in the same direction and causes the nozzle to move away from the adjoining end of the tested article. This step is completed when the bore 34 of the nozzle 23 moves beyond the opening 66. Satisfactory articles are retained by suction which is effective through the orifice 73, auxiliary opening 69, orifice 74, channel 11 and ducts 9. If the article is defective, the testing unit 51 sends to the valve 49 a signal at the time when the defective article reaches the auxiliary opening 69. The valve 49 opens and permits compressed air to flow from compressor 77a, through conduit 77, opening 76, channel 13 and orifices 12 whereby the jets or blasts of air issuing from these orifices eject the defective article from its grooves 7. Such defective article can drop into a collecting receptacle (not shown) to be transported to an apparatus wherein the filler is recovered for renewed introduction of tobacco into a cigarette machine.
When the opening 76 admits compressed air to effect ejection of a defective article, some air flows through the flow restricting orifice 75 and into the auxiliary opening 69 so that the retaining force generated by suction in the ports 9 is reduced considerably or drops to zero. In fact, there can develop in the opening 69 a pressure which slightly exceeds atmospheric pressure to insure that the defective article is not held by suction and can be readily expelled from its grooves 7.
A satisfactory article is held by suction while moving along the elongated opening 67 of the control ring 55. When the corresponding channel 11 moves beyond the left-hand end of the opening 67, it reaches the fresh air admitting opening 71 so that the inflowing atmospheric air reduces the suction to zero. From there on, the satisfactory article is held by the shields 108 and is transferred from the grooves 7 onto a further conveyor as soon as it advances beyond the shields 108. The corresponding suction channel 11 advances toward and past the opening 68 which admits compressed air to expel from the ports 9 and grooves 7 solid particles which might have entered such ports and grooves during transport of an article from the region of the main opening to the region downstream of the shields 108. The opening 68 receives compressed air by way of radial bore 63, bore 64, cutout 46, port 45 and bore 42.
If the apparatus of FIGS. 1 to 3 is to be employed for testing of articles of different lengths (for example, for testing articles which are longer than previously tested articles not because of inaccuracies developing during severing from a continuous rod but because the cutoff mechanism of the cigarette machine is intentionally adjusted to form longer cigarettes), the spacers 21 and 78 are replaced by shorter spacers. The position of flanges 6 and 79 is then changed accordingly but the position of other parts remains unchanged. If the next batch of articles contains articles which are shorter than the previously tested articles, the spacers 21 and 78 are replaced by spacers of greater axial length. The initiator 97 is preferably adjustable with reference to the drum 3.
FIG. 4 illustrates a portion of a modified testing apparatus. The testing drum 201 is rotatable about the axis of the shaft 202. The conduit which admits testing air to one end of an article is shown at 302 and the conduit which admits testing air to the other end of the same article is shown at 291. The conduits 291, 302 are connected with each other by a junction 400, and the testing unit 251 is located upstream of the junction 400, as considered in the direction of air flow into the conduits 291 and 302. The unit 251 is connected with a source 306 of testing air by way of a conduit which contains a flow restrictor or throttle 305.
The apparatus of FIG. 4 operates as follows:
The source 306 supplies testing air which flows through the throttle 305 and testing unit 251, conduit 302 and conduit 291. If the 'article which receives air from the conduits 291, 302 is satisfactory, its Wrapper permits escape of a relatively small amount of testing air. However, if the wrapper of the tested article has a leak or is torn at one or more points, the amount of escaping testing air exceeds a predetermined minimum amount so that a larger quantity of air must flow via testing unit 251 and toward the junction 400'. A portion of the testing cycle is cut off electronically to insure that faulty signals which can appear on entry into the testing zone for other reasons cannot produce a signal which would result in ejection of a satisfactory article. This is fully described in the aforementioned Esenwein application. For example, the configuration of lobes on the 'synchronizing cam of the drum 201 shown in FIG. 4 can be selected in a way to avoid generation of signals during blowing up of articles.
The operation of testing units 51 and 251 is analogous.
These testing units produce impulses at a frequency corresponding to the rate at which the articles travel through the testing zone. The impulses are indicative of satisfactory or unsatisfactory articles, depending on the pressure of air flowing through the venturi of the respective testing unit. The timing or synchronizing impulses are transmitted by the initiator 97 at a rate corresponding to the speed of lobes 36 on the cam 35. The signal storing unit in the circuit 96 produces impulses only when it receives an impulse from the initiator 97 simultaneously with an impulse from the capacitor in the chamber 94, i.e.,- when the capacitor produces an impulse which is indicative of a defective article. The accuracy of the initiator 97 (i.e., the accuracy of synchronization of impulses produced by initiator 97 with the frequency at which the lobes 36 travel past the initiator) is important because it determines the length of the zone in which the defective articles are ejected from the respective grooves 7.
An important advantage of our testing apparatus is that suction which holds articles in their grooves 7 can be reduced very rapidly and that a relatively low pressure of air currents which are admitted via orifices 12 sulfices to dislodge defective articles from their holders. Also, the apparatus may utilize a relatively small and lightweight regulating valve 49 whose inertia is low so that it can close and open without any appreciable delay. As stated before, the apparatus of our invention can be used with equal advantage for testing of cigarettes with or without filters, cigarillos, cigars with or without filters, filter rod sections and analogous rod shaped articles. Also, the apparatus can be used for testing of cigarettes or filter cigarettes or filter rod sections of unit length or multiple unit length.
If the cylinder 4 of the drum 3 is not provided with channels 13 and orifices 12, the opening 76 in the member 55 can be omitted and the conduit 77 then admits compressed air into ports 9 by way of the opening 69. When the valve 49 opens, the conduit 77 admits compressed gas into the suction ports 9 of a holder 8 which contains a defective article, and the gas expels the article from the respective grooves 7. In such apparatus, the grooves 7 of the holders 8 are preferably configurated in a way to prevent excessive buildup of suction between the wrapper of a defective article and the adjoining surfaces of the holders 8 because such suction would oppose the ejecting action of compressed gas issuing from the ports 9. Grooves wherein such suction does not develop are known in the art.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.
1. In an apparatus for testing and classifying cigarettes or like rod shaped articles, a combination comprising conveyor means provided with holder means for transporting a series of articles sideways, said holder means being provided with suction port means to retain satisfactory articles during travel past an ejecting station for defective articles; ejecting means provided at said station for expelling defective articles from the respective holder means, said ejecting means including conduit means for admitting a compressed gas with attendant reduction of suction in said port means whereby such gas expels defective articles from the respective holder means, and regulating means for controlling the admission of gas to said conduit means; and synchronizing means for synchronizing the operation of said regulating means with the rate of article travel past said ejecting station, said synchronizing means comprising cam means provided on said conveyor means and a contactless initiator arranged to transmit to said regulating means signals at the frequency determined by said cam means.
2. In an apparatus for testing and classifying cigarettes or like rod shaped articles, a combination comprising conveyor means provided with holder means for transporting a series of articles sideways, said holder means being provided with suction port means to retain satisfactory articles during travel past an ejecting station for defective articles; and ejecting means for expelling defective articles from the respective holder means, said ejecting means including conduit means for admitting a compressed gas which expels defective articles from the respective holder means, suction reducing means operative to reduce suction in the port means of holder means for defective articles not later than during admission of gas to said conduit means, and regulating means for controlling the admission of gas to said conduit means.
3. A combination as defined in claim 2, wherein said conduit means includes a single stationary supply conduit and orifice means adjacent to each suction port means and communicating with said supply conduit during travel past said ejecting station, said suction reducing means connecting said orifice means with the respective port means during travel past said ejecting station so that gas admitted via said conduit means can penetrate into the respective port means to reduce suction therein.
4. A combination as defined in claim 2, wherein said conduit means is arranged to admit gas through said conveyor means.
5. A combination as defined in claim 2, further c0mprising suction generating means and control means for connecting said suction generating means with said port means during travel of holder means past said ejecting station, said control means having main opening means connecting said port means with said suction generating means during travel toward said ejecting station and auxiliary opening means connected with said conduit means by way of said suction reducing means and with said suction generating means by way of said main opening means, said auxiliary opening means communicating with successive port means during travel of the respective holder means past said ejecting station.
6. A combination as defined in claim 2, further comprising testing means arranged to test successive articles upstream of said ejecting station and to produce signals in response to detection of defective articles, said regulating means comprising valve means installed in said conduit means to open in response to said signals.
7. A combination as defined in claim 6, wherein said conduit means comprises a single stationary supply conduit and at least one orifice provided in each of said holder means, the orifices of successive holder means being arranged to communicate with said supply conduit when the conveyor means is in motion and said valve means being installed in said supply conduit.
8, A combination as defined in claim 2, wherein said conveyor means comprises a member rotatable about a fixed axis and said holder means extend in parallelism with said axis, said member having means connecting at least one end of each successive article with a source of testing fluid upstream of said ejecting station, and further comprising testing means for determining the characteristics of testing fluid and for operating said regulating means to admit a gas to said conduit means when the thus determined characteristic is indicative of a defective article.
9. A combination as defined in claim 8, wherein said testing means comprises a venturi through which the testing fluid flows and means for determining the characteristics of testing fluid in said venturi while such fluid penetrates into an article upstream of said. ejecting station.
10. A combination as defined in claim 2, further comprising means for synchronizing the operation of said regulating means with therate of article travel past said ejecting station.
11. A combination as defined in claim conveyor means comprises a rotary drum.
12. A combination as defined in claim 2, wherein said conveyor means comprises means for clamping the articles during travel toward said ejecting station.
2, wherein said References Cited UNITED STATES PATENTS ALLEN N. KNOWLES, Primary Examiner US. Cl. X.R. 209-73, 74