US3769832A

US3769832A - Apparatus for testing cigarettes or the like

Info

Publication number: US3769832A
Application number: US00292632A
Authority: US
Inventors: A Baier
Original assignee: Hauni Werke Koerber and Co KG
Current assignee: Koerber AG
Priority date: 1971-10-08
Filing date: 1972-09-27
Publication date: 1973-11-06
Anticipated expiration: 1990-11-06
Also published as: FR2155359A5; GB1398571A; DE2150186A1; IT968576B

Abstract

A pneumatic cigarette testing apparatus wherein the drum which moves cigarettes sideways past a testing station carries one or two annuli of sealing devices having holders which are movable toward and away from the adjacent ends of cigarettes. Each holder supports an elastic annular sealing element whose internal diameter is normally less than the diameter of a cigarette wrapper but can be enlarged in response to axial movement of a deforming plunger in the respective holder. The sealing elements are expanded upstream of the testing station and the respective holders are thereupon moved axially so that the expanded sealing elements surround with some clearance the adjacent ends of aligned cigarette wrappers. The plungers allow the sealing elements to contract and to sealingly engage the ends of wrappers during travel past the testing station.

Description

Baier Nov. 6, 1973 [75] Inventor: Anton Baier, Ahrensburg, Germany [73] Assignee: Hauni-Werke Korber & Co. KG, [571 Hamburg, Germany [22] Filed: Sept. 27, 1972 [21] Appl. No.: 292,632

[30] Foreign Application Priority Data Oct. 8, 1971 Germany ..P2150 186.0

[52] U.S. Cl 73/41, 73/38, 73/49.8 [51] Int. Cl. G0lm 3/04 [58] Field of Search 73/41, 49.8, 45.1, 73/38 [56] References Cited UNITED STATES PATENTS 3,386,28l 6/1968 Menge et al. 73/41 46a 9a 1b 9 48 44 47 Z4 23\L 2 ,2 2 8 l l /L APPARATUS FOR TESTING CIGARETTES OR THE LIKE Primary Examiner-Donald O. Woodie] Att0rneyMichael S. Striker ABSTRACT A pneumatic cigarette testing apparatus wherein the drum which moves cigarettes sideways past a testing station carries one or two annuli of sealing devices having holders'which are movable toward and away from the adjacent ends of cigarettes. Each holder supports an elastic annular sealing element whose internal diameter is normally less than the diameter of a cigarette wrapper but can be enlarged in response to axial movement of a deforming plunger in the respective holder. The sealing elements are expanded upstream of the testing station and the respective holders are thereupon moved axially so that the expanded sealing elements surround with some clearance the adjacent ends of aligned cigarette wrappers. The plungers allow the sealing elements to contract and to sealingly engage the ends of wrappers during travel past the testing station.

12 Claims, 10 Drawing Figures l 1/4/4 jV/J M/% z APPARATUS FOR TESTING CIGARETTES on Tim I LIKE CROSS-REFERENCE TO RELATED INVENTION The testing apparatus of the present invention constitutes an improvement over and a further development of apparatus which is disclosed in commonly owned US. Pat. No. 3,386,281 granted June 4, 1968 to G. Menge et al.

BACKGROUND OF THE INVENTION The present invention relates to apparatus for testing cigarettes, filter rod sections, filter cigarettes and analogous rod-shaped articles wherein an open-ended tubular wrapper surrounds a fluid-permeable rod-like filler consisting of tobacco and/or filter material. More particularly, the invention relates to improvements in devices for sealing the ends of wrappers of such rodshaped articles during transport past a testing station where the condition of wrappers and/r fillers is tested by streams of a gaseous fluid. Still more particularly, the invention relates to improvements in sealing devices which are provided on a conveyor serving to transport rod-shaped articles past a testing station where the articles are preferably tested by streams of a gaseous fluid which is caused to enter one or both ends of each tested article. The purpose of the sealing devices is to sealingly engage the adjacent ends of wrappers of articles to be tested so as to prevent uncontrolled communication of testing fluid with surrounding atmospheric air.

U.S. Pat. No. 3,386,281 to Menge et al. discloses a testing apparatus wherein the conveyor which transports rod-shaped articles past a testing station carries one or two sets of sealing devices adjacent to the ends of flutes or analogous receiving means for rod-shaped articles. Each sealing device comprises an elastic sealing element defining an opening for reception of the end of a tubular wrapper. The diameter of the opening normally exceeds the diameter of a wrapper to allow for unimpeded insertion of a wrapper end. The sealing element is then deformed so that it sealingly engages the inserted wrapper during travel past the testing station, and is thereupon caused or allowed to enlarge the diameter of its opening so that the wrapper of the respective rod-shaped article can be withdrawn to allow for removal of the tested article from its flute, either at a transfer station for satisfactory articles or at an ejecting station where the defective articles are segregated from satisfactory articles. Each sealing element is an elastic hose which is mounted in a ring-shaped chamber. The reduction of the diameter of the opening of the sealing element takes place in response to admission of compressed air into the space surrounding the sealing element in the chamber. It was found that repeated deformation of such sealing elements by compressed air results in rapid fatigue of elastomeric material so that the sealing elements must be replaced at frequent intervals. This is a tedious and time-consuming operation because the chambers for the sealing elements are small and not readily accessible. Consequently, the replacement of defective sealing elements invariably entails substantial losses in output, especially since the testing conveyor normally forms part of a complex production line which must be brought to a full stop before an attendant can reach the chambers of sealing devices on the testing conveyor. The output of such production lines is in excess of 4,000 articles per minute so that even short-lasting stoppages invariably result in losses amounting to tens and hundreds of thousands of articles.

Furthermore, the pneumatic pressure which must be applied to the external surface of a tubular sealing element in order to insure satisfactory sealing engagement with the ends of cigarette wrappers or the like is relatively high so that the ends of wrappers are likely to undergo lasting deformation which affects the appearance of the final product. The likelihood of permanent deformation isespecially pronounced if the pressure of fluid which is used to deform the sealing elements even slightly exceeds an optimum pressure and/or if the ends of fillers in the rod-shaped articles are softer than anticipated.

SUMMARY OF THE INVENTION An object of the invention is to provide a testing apparatus for cigarettes or analogous rod-shaped articles having open-ended tubular wrappers wherein the sealing devices which are used to sealingly engage the ends of wrappers during testing of the respective articles are less likely to permanently deform the wrappers than the sealing devices of presently known testing apparatus.

Another object of the invention is to provide the sealing devices with novel and improved elastic sealing elements for the ends of wrappers whose deformation can be regulated with a high degree of accuracy and which can be used for long periods of time without any changes in their sealing action.

A further object of the invention is to provide a conveyor which serves to carry the improved sealing devices and to provide a testing apparatus which embodies the conveyor.

An additional object of the invention is to provide sealing devices which can be used with equal advantage in apparatus wherein cigarettes or analogous rodshaped articles are tested by a compressed fluid or in apparatus wherein the articles are tested by a fluid whose pressure is below atmospheric pressure.

An additional object of the invention is to provide sealing elements which are readily accessible at all times so that their inspection, adjustment and/or replacement requires less time than in testing apparatus employing presently known elastic sealing elements.

An ancillary object of the invention is to provide novel deforming means for the improved sealing elements.

The apparatus of the present invention is used for pneumatically testing. cigarettes or analogous rodshaped articles including openended tubular wrappers having predetermined diameters. The apparatus comprises a conveyor'(e.g., a rotary drum) having a plurality of preferably equidistant receiving means for rodshaped articles (each receiving means may constitute a flute located at the periphery and parallel to the axis of the drum) and arranged to move the receiving means seriatim past an article testing station, and a plurality of sealing devices each of which is associated with one of the receiving means and comprises a holder mounted on the conveyor for movement toward and away from the respective receiving; means, a sealing element mounted in the holder and having an elastic article-engaging annular portion with an internal diameter which is normally less than the diameter of a wrapper, and deforming means movable relative to the holder to and from an operative position in which the deforming means subjects the sealing element to axial stresses resulting in an increase of the internal diameter beyond the diameter of a wrapper.

The apparatus further comprises first displacing means for moving the deforming means of successive sealing devices to their operative positions upstream of the testing station so that the internal diameters of the respective annular portions increase beyond the diameter of a wrapper, and second displacing means for moving the holders toward the respective receiving means in operative positions of the corresponding deforming means to thus effect the entry of adjacent wrapper ends of articles in the receiving means into the adjacent annular portions not later than when the annular portions reach the testing station. The deforming means allow the respective annular portions to contract during travel past the testing station so that the annular portions sealingly engage the surrounded wrapper ends.

The deforming means are caused to expand the respective annular portions downstream of the testing station and the second displacing means then causes the respective holders to move away from the associated receiving means so that the annular portions can be moved axially of and away from the adjacent wrapper ends.

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 additionalfeatures 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 fragmentary axial sectional view of a conveyor forming part of a cigarette testing apparatus and provided with two annuli of sealing devices embodying the invention;

FIG. 2 is a similar fragmentary axial sectional view of a conveyor which is provided with a single annulus of sealing devices;

FIG. 3a is an enlarged fragmentary axial sectional view of one of the sealing devices shown in FIG. 1;

FIG. 3b is a front elevational view of the wrapperengaging annular portion of the sealing element in the sealing device shown in FIG. 30;

FIG. 4 is a diagram showing a first testing unit for cigarettes on the conveyor of FIG. 1;

FIG. 5 is a similar diagram showing a second testing unit for cigarettes on the conveyor of FIG. 1;

FIG. 6 is a diagram showing a third testing unit for cigarettes on the conveyor of FIG. 1;

FIG. 7 is a diagram similar to that of FIG. 6 but showing a unit for testing of cigarettes by means of a testing fluid which is sucked through the filler of the cigarette at one end of the wrapper;

FIG. 8 is a diagram showing a first testing unit for cigarettes on the conveyor of FIG. 2; and

FIG. 9 is a diagram of a second testing unit for cigarettes on the conveyor of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, there is shown a portion of a pneumatic testing apparatus for filter cigarettes 8 of double unit length. The testing apparatus comprises a conveyor 1 here shown as a rotary drum having a plurality of axially parallel peripheral receiving means in the form of composite flutes 2 each of which can receive and retain a cigarette 8 so that the respective cigarette travels sideways. The flutes 2 receive successive cigarettes 8 at a first transfer station (not shown) and transport the cigarettes toward, through and beyond the illustrated testing station where the cigarettes are tested by a gaseous fluid in a manner to be described in connection with FIG. 4. The satisfactory cigarettes 8 are removed from the flutes 2 at a second transfer station located downstream of the testing station, and the defective cigarettes 8 are expelled from their flutes at an ejecting station which is normally located downstream of the testing station and can be positioned ahead of or downstream of the second transfer station. The conveyor 1 is provided with sets of four radially extending suction ports 3, one for each section of a composite flute 2, and the inner ends of all four suction ports 3 which are associated with a given flute 2 communicate with an axially parallel suction channel 4 which is a blind bore having its open end at the lefthand end face of the conveyor 1. A stationary valve plate (not shown) of customary design is provided to temporarily connect successive sets of suction ports 3 with a suitable suction generating device (e.g., a fan) so that the cigarettes 8 are held in the respective flutes by suction during transport from the first transfer station to the second transfer station, i.e., also during transport past the testing station. It is clear that the suction ports 3 can be replaced by one or more shrouds or other mechanical retaining means for temporarily holding cigarettes 8 in the respective flutes 2. The connection between the arcuate suction groove of the valve plate and the suction generating device preferably comprises a suitable adjustable regulating valve (not shown) which determines the force with which the cigarettes 8 are held in the flutes 2 by suction during transport between the two transfer stations.

The conveyor 1 is further provided with radially extending bores 6 for discharge of compressed air, there being one pair of bores 6 for each flute 2. The inner ends of the paris of bores 6 communicate with discrete axially parallel channels 7 each of which is a blind bore having its open end located at the left-hand end face of the conveyor 1, as viewed in FIG. 1. The aforementioned valve plate has a second arcuate groove which can establish communication between successive channels 7 and a source of compressed air (e.g., a blower) in response to opening of a regulating valve (not shown) which is controlled by the testing unit of the apparatus. The testing unit opens the regulating valve with a delay following the detection of a defective cigarette 8. The streams of compressed air then expel the defective cigarette 8 at the aforementioned ejecting station regardless of whether or not the defective cigarette is attracted by suction because the streams of compressed air issuing from the bores 6 can overcome the suction with which the defective cigarettes are attracted to the respective flutes 2.

Each end portion of the drum-shaped body of the conveyor 1 carries a supporting ring 9 for an annulus of sealing devices 11, one for each flute 2. Each testing device I 1 comprises a holder 1 1a which is movable axially of the respective supporting ring 9 toward and away from the adjacent end of the associated flute 2. Each holder 11a is coupled to the respective ring 9 by a helical spring 12 which tends to expand and to push the respective holder 1 la toward the adjacent axial end of the conveyor 1, Le, away from the aligned flute 2. As shown in FIG. 1, one end of each spring 12 is attached directly to the respective ring 9 and the other end of each spring 12 is attached to a post 11b of the corresponding holder 11a. Each holder 110 further comprises an outwardly projecting extension or arm 11c which carries the radially extending shaft 13a of a roller follower 13 serving to track the face of a stationary ring-shaped displacing cam 14 mounted in the frame of the testing apparatus adjacent to the path of movement of testing devices 11 with the conveyor 1. The springs 12 serve to bias the corresponding roller followers 13 against the adjacent displacing cams 14. The configuration of the face on each cam 14 is such that successive holders 1 1a move toward the respective flutes 2 during travel toward the testing station (namely, between the first transfer station and the testing station), that the holders 11a thereupon remain in their inner end positions during travel past the testing station, and that the holders 11a move away from the respective flutes 2 during travel of the respective testing devices 11 between the testing station and the second transfer station.

The testing apparatus further comprises a stationary shoe 16 for each supporting ring 9. Each shoe 16 has a concave surface which is biased against the peripheral surface of the respective ring 9 and each shoe further comprises a nipple 16a serving for connection of a hose or conduit 33 (see FIG. 4) which admits a pressurized testing fluid, e.g., air. The concave surface of each shoe 16 has an elongated slot 16b which communicates with successive ring-shaped internal grooves 9a of the respective ring 9. The grooves 9a communicate with radial bores 17 of the respective holders 11a.

Each sealing device 11 further comprises a deforming element in the form of a plunger 18 which is movable in the respective holder 11a in parallelism with the aligned flute 2 and is biased outwardly, i.e., away from the adjacent end of the aligned flute 2, by a helical spring 23 which reacts against the corresponding holder 11a. The outer end portion of each plunger 18 carries a roller follower 21 which tracks the face of a stationary displacing cam 22 mounted in the frame of the testing apparatus adjacent to the path of movement of the corresponding annulus of sealing devices 11. Each plunger 18 hasan axial blind bore 24 which communicates with the radially extending bore 17 of therespective holder 11a so that the bores 24 receive testing fluid during travel of the corresponding sealing devices 11 past the testing station, i.e., along the shoes 16.

In accordance with a feature of the invention, the plungers 18 serve to temporarily deform elastic tubular sealing elements 19 each of which is fixedly mounted in the respective holder 11a and has a wrapperengaging annular front portion or lip 29 (see FIGS. 3a and 3b) having an internal diameter 27 which is normally less than the diameter of a satisfactory cigarette wrapper. Thus, in order to allow the annular portion 29 of a sealing element 19 to surround the adjacent end of a cigarette wrapper, the diameter 27 must be increased to a value which exceeds (at least slightly) the diameter of the wrapper in the adjacent flute 2. Such deformation or enlargement is effected by the respective plunger 18 whichis caused by the associated displacing cam 22 to move deeper into the respective sealing element l9 and to thereby subject the sealing element to axial deforming stresses resulting in radial expansion of the annular portion 29. Each sealing element 19 has an axial bore or passage 26 which communicates with the axial blind bore 24 of the respective deforming plunger 24 to admit testing fluid into the adjacent end of a cigarette filler during travel past the testing station.

As shown in FIG. 3a, each sealing element 19 has a cylindrical external surface 31 which is fixedly held in a complementary bore of the corresponding holder 1 1a, e.g., by resorting to a suitable adhesive. The internal diameter 32 of the sealing element 19 matches the external diameter of the respective deforming plunger 18. The front end portion of the plunger 18 defines a socket 18a for reception of the hub 28a of a hollow frustoconical section 28 of the sealing element 19, and the conical section 28 has an end face 25 located at its smaller-diameter end and being positioned to receive axial stresses from the plunger 18. As the conicity of the section 28 decreases in response to rightward movement of the plunger 18, as viewed in FIG. 3a, the annular wrapper-engaging portion 29 is caused to expand and to increase its diameter 27 beyond the diameter of a wrapper. To enhance the elasticity of the annular portion 29, the latter is preferably provided with one or two sets of radially extending teeth alternating with weakened zones which allow for ready expansion of the annular portion 29 in response to rightward axial movement of the plunger 18. FIG. 3b shows the radially extending teeth 29a at the outer side of the annular portion 29, namely, at that side of the annular portion 29 which faces the adjacent end of a cigarette 8 in the aligned flute 2. The inner side of each annular portion 29 can be provided with similarly distributed teeth. Each plunger 18 is freely reciprocable in the bore 32 of the respective sealing element 19 under the action of the displacing cam 22 or under the action of the respective helical spring 23.

FIG. 4 is a diagram of the testing unit in the testing apparatus which embodies the structure shown in FIGS. 1, 3a and 3b. The nipples 16a of the shoes 16 of FIG. 1 are connected with the hoses or conduits 33 which supply a compressed testing fluid; e.g., air. The intake ends of the conduits 33 are connected to a junction 33a which is further connected with a pressure gauge 34 and with a source 37 of compressed gaseous testing fluid, e.g., an air blower. The conduit 35 which connects the source 37 with the junction 330 contains an adjustable pressure regulating valve 38 and a flow restrictor 36.

The operation of the testing apparatus which includes the structure of FIGS. 1, 3a, 3b and 4 is as fol lows:

When a supply conveyor (not shown) delivers a fresh cigarette 8 into a flute 2 at the first transfer station which is located ahead of the testing station (shoes 16), the holders 11a of the respective sealing devices 11 are allowed by the displacing cams 14 to move to predetermined positions at a maximum distance from the flute 2 at the first transfer station. Therefore, the cigarette 8 can be readily introduced into the flute 2 and is held therein by suction in the respective ports 3. The suction is sufficient to hold the cigarette 8 against ejection under the action of gravity and/ or centrifugal force. The introduction of cigarettes 8 into the flutes 2 at the first transfer station takes place in such a way that the ends of cigarettes do not touch the adjacent sealing elements 19. The conveyor 1 continues to rotate and advances the freshly admitted cigarette 8 toward the testing station, i.e., into the space between the shoes 16. During such transport, the displacing earns 14 and 22 respectively cause the corresponding holders 11a and plungers 18 to move toward the adjacent ends of the cigarette 8. In the first step, the plungers l8 bear against the adjacent end faces 25 and cause the sections 28 of the respective sealing elements 19 to expand the associated wrapper-engaging annular portions 29 so that the diameters 27 of the annular portions 29 in-' crease to exceed the average diameter of a wrapper. The plungers l8 thereupon hold the respective annular portions 29 in the expanded positions during further travel of the respective sealing devices 11 toward the testing station. At the same time, the displacing cams 14 cause the respective holders 11a to move toward each other so that the annular portions 29 receive the adjacent ends of the wrapper on the cigarette 8 with some clearance. Before the holders lla actually reach the testing station, the plungers 18 are caused to move outwardly by the respective springs 23 so that the annular portions 29 are free to contract and to thereby sealingly engage the adjacent wrapper ends. Such sealing engagement remains unchanged during travel of the cigarette 8 past the testing station, i.e., between the shoes 16. The sealing action of the annular portions 29 is determined by their configuration and elasticity.

During travel of a cigarette 8 (whose wrapper is sealingly engaged by the adjacent annular portions 29) past the testing station, the shoes 16 admit into the respective wrapper ends two streams of a gaseous testing fluid by way of the respective grooves 9a and bores 17, 24, 26. The shoes 16 receive pressurized testing fluid from the respective conduits 33, and these conduits receive testing fluid from the source 37 by way of the conduit 35. If the wrapper of a cigarette 8 at the testing station exhibits a leak (e.g., a hole or a defective seam), the pressure of testing fluid in the conduits 33 drops due to escape of testing fluid through the leak, whereby the pressure gauge 34 produces a signal which is transmitted to the aforementioned regulating valve controlling the admission of compressed gas into the respective bores 7 and 6 with the result that the defective cigarette 8 is expelled from its flute 2 at the ejecting station which is preferably located downstream of the testing station. As mentioned above, the pressure of gas which is admitted into the bores 6 adjacent to the flute 2 which contains a defective cigarette is high enough to overcome the suction in the respective ports 3 so that the defective cigarette is invariably expelled from its flute. The connection between the pressure gauge 34 and the aforementioned regulating valve for admission of compressed gas into the bores 6 preferably contains a suitable transducer. The placing of the ejecting station downstream of the testing station is desirable in order to provide time for detachment of wrapperengaging annular portions 29 from the adjacent wrapper ends prior to ejection of defective cigarettes. The detachment of annular portions 29 takes place in response to movement of the respective deforming plungers 18 toward the respective flute 2 so as to increase the diameters 27 of the corresponding annular portions 29 above the average diameter of a wrapper. The displacing earns 14 thereupon allow the springs 12 to move the holders 1 la away from the adjacent flutes 2 so that the annular portions 29 (which are held in expanded condition by the respective plungers 18) can be moved away from the adjacent wrapper ends in order to permit for unimpeded removal of satisfactory cigarettes 8 at the second transfer station and for unimpeded expulsion of defective cigarettes 8 at the ejecting station. The removal of satisfactory cigarettes 8 at the second transfer station can take place by gravity (if the second transfer station is located at a level below the axis of the conveyor l) or by admission of compressed air into the respective bores 6. The ports 3 are sealed from the suction generating means not later than when the satisfactory cigarettes reach the second transfer station.

FIG. 2 illustrates a portion of a second testing apparatus wherein all such parts which are identical with or clearly analogous to the corresponding parts of the structure shown in FIGS. 1, 3a and 3b are denoted by similar reference characters plus 100. The drumshaped conveyor 141 carries a single supporting ring 109 for a single annulus of sealing devices 111. The other annulus of sealing devices is replaced by an annular flange 143 at the right-hand axial end of the conveyor 141. The articles 142 to be tested are plain or fil ter cigarettes of unit length. As shown in FIG. 8, each cigarette 142 which reaches the testing station receives a stream of testing fluid by way of a single conduit or hose 133 which is attached to the nipple 116a of the shoe 116 of FIG. 2. The right-hand end of the wrapper of such cigarette is biased against the flange 143 which acts as a sealing means. When the conduit 133 admits pressurized sealing fluid, the fluid escapes through one or more leaks in the wrapper of a defective cigarette whereby the pressure gauge 134 in the conduit 133 furnishes a signal which is transmitted to a transducer and thence to the regulating valve which controls the admission of compressed gas into the respective bore 106 (see FIG. 2) so that the defective cigarette is expelled from its flute 102. The conduit 133 receives testing fluid from a blower 137 and contains a pressure regulating valve 138 as well as a flow restrictor 136.

The conveyor 141 of FIG. 2 resembles one-half of the conveyor 1 shown in FIG. 1. It is clear, however, that the conveyor 141 can be used with equal advantage for the testing of cigarettes or like rod-shaped articles (such as cigarillos, cheroots or cigars) of double unit length. The pressing of cigarette wrappers against the flange 143 is brought about by the displacing cam 114 which causes the respective holders 1110 to move in a direction to the right, as viewed in FIG. 2, after the lefthand end portions of the wrappers are already sealingly engaged by the corresponding sealing elements 119.

FIG. 5 illustrates a modified testing unit which can beused with the conveyor 1 of FIG. 1. The source 37 (FIG. 4) of compressed gaseous testing fluid is replaced with a suction fan 237 which draws air through the wrapper ends of the respective cigarette 208 by way of the conduits 233. When a cigarette 208 is satisfactory, the conduits 233 receive and convey only such air which penetrates the cigarette 208 through its porous wrapper. However, if the wrapper of the cigarette exhibits a leak or a portion of the cigarette is missing, the pressure in the conduits 233 rises and such rise in pressure is detected by the gauge 234 which causes the regulating valve of the ejector means to admit compressed air into the respective bores 6 of the conveyor 1. The conduit 235 which is connected with the junction 233a contains a pressure regulating valve 238 and a flow restrictor 236.

Referring to FIG. 6, there is shown a testing unit which can be used with the conveyor 1 of FIG. 1 as a substitute for the testing unit of FIGS. 4 or 5. This testing unit comprises a source 337 of compressed gaseous testing fluid which is connected with one of the conduits 333 by way of an adjustable pressure regulating valve 338. The left-hand conduit 333 further contains a flow restrictor 336, a first pressure gauge 346 which is located upstream of the flow restrictor 336, and a second pressure gauge 347 connected with the lefthand conduit 333 downstream of the flow restrictor 336. The right-hand conduit 333 of FIG. 6 contains a flow restrictor 349 and a pressure gauge 348 located upstream of the flow restrictor 349. The article to be tested is shown at 308; this article is assumed to be a filter cigarette of double unit length including a centrally located filter rod section of double unit length and two plain cigarettes of unit length. If the apparatus which embodies the conveyor 1 of FIG. 1 uses the testing unit of FIG. 6, one of the nipples 16a is connected with the right-hand conduit 333 of FIG. 6 and the other nipple 16a is connected with the left-hand conduit 333 of FIG. 6. The testing fluid enters only one end of the wrapper at the testing station and is allowed to escape at the other end of the wrapper.

The pressure gauge 346 has a dial and a pointer serving to indicate the pressure of testing fluid which pressure is selected by the adjusting valve 338. The

gauges

347, 348 can be observed to indicate the drop in pressure of testing fluid during flow through the cigarette 308. When the wrapper of a cigarette 308 has one or more leaks, the gauge 348 indicates the excessive drop of pressure and generates a signal which is transmitted to a transducer and thence to the regulating valve which controls the admission of compressed air into the respective bores 6 of the conveyor 1 to bring about a segregation of the defective cigarette.

FIG. 7 shows a testing unit which can be used with the conveyor 1 of FIG. 1 and differs from the testing unit of FIG. 6 in that the source 337 of compressed testing fluid shown in FIG. 6 is replaced with a suction generating device 437 (e.g., a fan) which draws a stream of atmospheric air through the right-hand conduit 433 (which contains a pressure gauge 448 and a flow restrictor 449) and thereupon through the lefthand conduit 433 which contains a first pressure gauge 447, a flow restrictor 436, a second pressure gauge 446 and an adjustable pressure regulating valve 438. The gauge 447 generates a signal which results in ejection of the tested cigarette 408 if the pressure differential between the two ends of the cigarette wrapper exceeds a predetermined value, i.e., if the wrapper has one or more leaks which allow atmospheric air to enter the left-hand conduit 433 by a route other than via the right-hand conduit 433.

The testing unit of FIG. 9 can be used with the com veyor 141 of FIG. 2 as a substitute for the testing unit of FIG. 8. The article to be tested is shown at 642; one end of the wrapper of this article is caused to abut against the flange 143 of the conveyor 141 and the other end of the wrapper is connected by nipple 116a with a conduit 633 while the respective cigarette642 advances past the testing station, i.e., past the shoe 1 16 of FIG. 2. The reference character 637 denotes a suction generating device which draws air through the conduit 633 whereby a gauge 63.4 produces a signal for ejection of the cigarette if the wrapper of the tested cigarette has a leak which allows unobstructed or substantially unobstructed flow of air into the conduit 633. The latter further contains a flow restrictor 636 and an adjustable pressure regulating valve 638. The intake end of the conduit 633 is connected with a cigarette 642 at the testing station by way of the shoe 116, the supporting ring 109, the respective holder 1 I la, the respective deforming plunger 118, and the respective sealing element 119. I

An important advantage of the improved testing apparatus is that the elasticity and dimensions of each sealing element 19 or 119 (in undeformed condition of the sealing element) can be readily selected with a high degree of accuracy to insure that the annular portion 29 or 129 of the sealing element engages the adjacent end of a wrapper with a requisite force which is sufficient to insure a highly satisfactory sealing action but does not result in permanent deformation of tested articles. Also, the sealing

elements

19 or 119 are readily accessible so that the replacement of a defective sealing element takes up very little time. The wear on the sealing elements is minimal because they do not slide relative to the articles to be tested so that each sealing element is capable of standing long periods of use without premature aging and/or changes in its sealing action. It was found that repeated pneumatic deformation of sealing elements of the type disclosed in the aforementioned patent to Menge et al. brings about more rapid aging of sealing elements than when the sealing elements are deformed by the

plungers

18 or 118 in a manner as described in connection with FIGS. 1, 2, 3a and 3b. Also, the improved sealing elements can be mass-produced at a low cost and they can be used with equal advantage for the testing of a wide variety of rodshaped articles which embody open-ended tubular wrappers. Such articles include plain or filter tipped cigarettes, cigarillos, cigars or cheroots of unit length or multiple unit length as well as plain or multiplex filter rod sections of any desired practical length. 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 my contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by LettersPatent is set forth in the appended:

1. In an apparatus for pneumatically testing cigarettes or analogous rod-shaped articles including openended tubular wrappers having a predetermined diameter, a conveyor having a plurality of receiving means for rod-shaped articles and arranged to move said re ceiving means seriatim past a testing station; a plurality of sealing devices each associated with one of said receiving means and each comprising a holder mounted on said conveyor for movement lengthwise of the respective receiving means, a sealing element mounted in said holder and having an elastic wrapper-engaging annular portion with an internal diameter which is normally less than said predetermined diameter, and deforming means movable relative to said holder to and from an operative position in which said deforming means subjects said sealing element to axial stresses resulting in an increase of said internal diameter beyond said predetermined diameter; first displacing means for moving the deforming means of successive sealing devices to said operative positions upstream of said testing station so that the internal diameters of said annular portions increase beyond said predetermined diameter; and second diplacing means for moving said holders toward the respective receiving means in operative positions of the respective deforming means to thus efiect the entry of adjacent wrapper ends of articles in the respective receiving means into the deformed annular portions not later than when the respective sealing devices reach said testing station, said deforming means being arranged to allow for contraction of the respective annular portions during travel past said testing station so that said annular portions contract and sealingly engage the adjacent wrapper ends.

2. In an apparatus as defined in claim 1, wherein said first displacing means is arranged to move successive deforming means to said operative positions downstream of said testing station to thus disengage the respective annular portions from the adjacent wrapper ends, said second displacing means being arranged to move successive holders away from the respective receiving means downstream of said testing station while the respective deforming means assume said operative positions so that said annular portions are separated from the adjacent wrapper ends.

3. In an apparatus as defined in claim 1, wherein each of said sealing elements has a passage for testing fluid, said passage communicating with the wrapper end which is sealingly engaged by the respective annular portion.

4. In an apparatus as defined in claim 1, wherein each of said deforming means comprises a plunger and said first displacing means comprises means for moving said plungers axially.

5. In an apparatus as defined in claim 4, wherein each of said plungers comprises follower means and said means for moving said plungers comprises stationary cam means adjacent to the path of movement of said sealing devices and being tracked by said follower means.

6. In an apparatus as defined in claim 1, wherein each of said holders comprises follower means and said second displacing means comprises stationary cam means adjacent to the path of movement of said sealing devices and being tracked by said follower means.

7. In an apparatus as defined in claim 1, wherein each of said annular portions is contractible into and expandible from sealing engagement with wrapper ends, each of said sealing elements further comprising a ringshaped section having an end face located in the path oF movement of the respective deforming means to expand said annular portion in response to movement of the respective deforming means to said operative position.

8. In an apparatus as defined in claim 7, wherein said annular section is a hollow conical frustum and said end face is located at the smaller-diameter end of said frustum.

9. In an apparatus as defined in claim 1, wherein said deforming means and the respective sealing elements are provided with communicating passages for a gaseous testing fluid.

10. In an apparatus as defined in claim 1, wherein said conveyor is a rotary drum and said receiving means are axially parallel flutes provided at the periphery of said drum.

11. In an apparatus as defined in claim 10, wherein said sealing devices form a single annulus adjacent to one axial end of each flute.

12. In an apparatus as defined in claim 10, wherein said sealing devices form two annuli and said flutes are located between said annuli.

Claims

1. In an apparatus for pneumatically testing cigarettes or analogous rod-shaped articles including open-ended tubular wrappers having a predetermined diameter, a conveyor having a plurality of receiving means for rod-shaped articles And arranged to move said receiving means seriatim past a testing station; a plurality of sealing devices each associated with one of said receiving means and each comprising a holder mounted on said conveyor for movement lengthwise of the respective receiving means, a sealing element mounted in said holder and having an elastic wrapper-engaging annular portion with an internal diameter which is normally less than said predetermined diameter, and deforming means movable relative to said holder to and from an operative position in which said deforming means subjects said sealing element to axial stresses resulting in an increase of said internal diameter beyond said predetermined diameter; first displacing means for moving the deforming means of successive sealing devices to said operative positions upstream of said testing station so that the internal diameters of said annular portions increase beyond said predetermined diameter; and second diplacing means for moving said holders toward the respective receiving means in operative positions of the respective deforming means to thus effect the entry of adjacent wrapper ends of articles in the respective receiving means into the deformed annular portions not later than when the respective sealing devices reach said testing station, said deforming means being arranged to allow for contraction of the respective annular portions during travel past said testing station so that said annular portions contract and sealingly engage the adjacent wrapper ends.

7. In an apparatus as defined in claim 1, wherein each of said annular portions is contractible into and expandible from sealing engagement with wrapper ends, each of said sealing elements further comprising a ring-shaped section having an end face located in the path oF movement of the respective deforming means to expand said annular portion in response to movement of the respective deforming means to said operative position.