Abstract:
Rod-shaped articles of the tobacco processing industry are advanced lengthwise in a conduit by a first air flow. Blasts of compressed air are admitted into the conduit behind successive articles to promote their advancement in a larger-diameter arcuate section of the conduit, particularly from a lower level to a higher level. The admission of successive blasts of compressed air is carried out by an open-and-shut valve which receives signals from an article detector located downstream of the valve.

Description:
CROSS-REFERENCE TO RELATED CASES 
     This application claims the priority of commonly owned German patent application Ser. No. 199 37 636.0 filed Aug. 12, 1999. The disclosure of the above-referenced German patent application, as well as that of each U.S. and/or foreign patent and patent application mentioned in the specification of the present application, is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to improvements in methods of and apparatus or systems for pneumatically transporting successive commodities of a series of commodities in a conduit wherein the commodities are propelled by a flow or stream of a gaseous fluid, e.g., compressed air. 
     Systems of the above outlined character are utilized for the transport of numerous commodities, for example, to advance plain or filter cigarettes, filter rod sections and/or other rod-shaped articles or products of the tobacco processing industry into or from storage facilities and/or between different levels, as well as to change the orientation (such as the direction of advancement) of successive products (e.g., through angles close to or matching 90°). 
     In order to ensure predictable and efficient advancement of certain commodities by resorting to a pneumatic transporting system, especially the transport of products into and from mass-producing machines or production lines, it is necessary to design the path for the advancement of successive commodities (normally within a pneumatic conduit) in such a way that the commodities are compelled to advance in the conduit with minimal or negligible play, i.e., that a small or very small quantity of the selected gaseous fluid can flow around and forwardly beyond the conveyed commodities. In other words, the efficiency of a conventional transporting system for discrete commodities depends, to a large extent, upon the configuration and upon the dimensions of the path which is established for pneumatic propulsion of discrete commodities from a first station (sender) to a second station (receiver). 
     Numerous problems arise when a pneumatic transporting system is selected for the advancement of elongated rod-shaped commodities such as plain or filter cigarettes, rod-shaped sections of filters for tobacco smoke and/or other rod-shaped products of the tobacco processing industry. For example, if a cigarette or another non-elastic rod-shaped commodity is to be transported within a conduit along a path which is configurated to change the orientation of the cigarette (e.g., through a right angle or thereabout), it is necessary to increase the inner diameter of a certain length of the conduit in order to ensure that the cigarette can change the direction of its advancement (e.g., from horizontally to vertically or vice versa) without undergoing any (or any appreciable) permanent deformation. 
     The just discussed problems can be overcome, at least to a certain extent, if there is ample room to accommodate a conduit having one or more arcuate sections with large radii of curvature. However, such room is not always available (or is not available at all) in numerous plants (such as in cigarette making factories) which are designed for mass production of rod-shaped articles and wherein hundreds of discrete machines or production lines are normally installed in a single room in close or immediate proximity to each other. 
     In accordance with heretofore known proposals, the above outlined problems are sought to be overcome by employing pneumatic conduits which include arcuate sections having large or huge inner diameters so that a cigarette or an analogous essentially non-elastic commodity can change the direction of its advancement without undergoing any (or any appreciable) permanent deformation. Reference may be had, for example, to published German patent application Ser. No. 21 65 782. However, and as already pointed out hereinbefore, the efficiency of such pneumatic transporting systems is low (and often too low) because a high percentage of gaseous fluid (such as compressed air) is free to bypass a cigarette advancing in a large-diameter arcuate section of the conduit. The situation is aggravated if the cigarettes are to be advanced from a lower level to a higher level, i.e., when the gaseous conveying fluid is compelled to overcome the action of gravity force upon the advancing commodities. For example, the just outlined situation can develop when filter rod sections (e.g., filter mouthpieces of double or six times unit length) are to be transported from a filter rod making machine (e.g., a machine of the type disclosed in U.S. Pat. No. 3,974,007 granted Aug. 10, 1976 to Greve for “METHOD AND APPARATUS FOR THE PRODUCTION OF FILTER ROD SECTIONS OR THE LIKE”) to a tipping machine (e.g., a machine of the type described and illustrated in commonly owned U.S. Pat. No. 5,135,008 granted Aug. 4, 1992 to Oesterling et al. for “METHOD OF AND APPARATUS FOR MAKING FILTER CIGARETTES”). 
     OBJECTS OF THE INVENTION 
     An object of the present invention is to provide a pneumatic transporting system which overcomes the aforediscussed drawbacks of conventional systems in a simple, efficient and space-saving manner. 
     Another object of the invention is to provide a pneumatic transporting system which can be utilized with particular advantage in tobacco processing plants for controlled and predictable conveying of huge quantities of rod-shaped articles (such as plain or filter cigarettes, cigars or cigarillos and/or filter rod sections) between different levels and/or through great distances at a high frequency such as is required in a modern tobacco processing plant. 
     A further object of the invention is to provide a novel and improved method of transporting huge quantities of cigarettes, filter rod sections and/or other non-elastic rod-shaped commodities through short and/or great distances as well as between different levels (if and when necessary) without affecting the integrity, the appearance and/or other desirable characteristics of the conveyed commodities. 
     An additional object of the invention is to provide a cigarette making machine or production line which embodies one or more transporting systems exhibiting the above outlined characteristics. 
     Still another object of the invention is to provide the improved apparatus with a novel and improved combination of a conduit and one or more gas flow admitting and regulating units. 
     A further object of the instant invention is to provide an economical pneumatic transporting apparatus which can be put to use as a superior substitute for heretofore known apparatus for the transport of rod-shaped commodities of the tobacco processing industry. 
     SUMMARY OF THE INVENTION 
     One feature of the present invention resides in the provision of a transporting system for a series of commodities, e.g., rod-shaped commodities such as filter mouthpieces of multiple unit length. The improved apparatus comprises a pneumatic conduit which defines a predetermined path for successive commodities of the series and for a first stream or flow of a gaseous fluid (such as compressed air) serving to propel the commodities along the path in a predetermined direction, and means for admitting into the path an additional flow of gaseous fluid which assists the first flow in propelling commodities in the predetermined direction. 
     The conduit is or can be provided with discrete first and second inlets which respectively serve to admit the first flow and the additional flow into the predetermined path. At least one of the flows can contain compressed air, i.e., a compressed gaseous fluid. 
     The conduit can include an arcuate section which is located downstream of the second inlet (as considered in the predetermined direction). That portion of the path which is defined by the arcuate section of the conduit can have a cross-sectional area larger than that of the conduit section(s) located upstream and/or downstream of the arcuate section. For example, the arcuate section of the path can be designed (curved) in such a way that it can change the direction of transport of successive commodities through an angle which matches or approximates a right angle. 
     The second inlet can be defined by an adjustable valve, e.g., by a signal-responsive open-and-shut valve which is set up to intermittently admit the gaseous fluid of the additional flow into the elongated path by way of the second inlet. Such system can further include regulating means for opening the valve in response to propulsion (by the first flow) of a commodity past the second inlet. The regulating means can include at least one sensor which serves to monitor the path for the presence of commodities in the region of the second inlet. The sensor is arranged to generate signals which serve to effect an opening of the valve in response to advancement of commodities beyond the second inlet. 
     If the commodities are rod-shaped articles, the path can include a portion having a circular cross-sectional outline, located at the second inlet and having a diameter which at least approximates the diameter of a rod-shaped article. 
     Another feature of the present invention resides in the provision of a method of transporting a series of commodities, e.g., rod-shaped articles of the tobacco processing industry. The improved method comprises the steps of establishing an elongated path for the advancement of successive commodities of the series, pneumatically propelling successive commodities in a predetermined direction along the path by resorting to a first flow (stream) of a gaseous fluid, and introducing into the path a second flow of a gaseous fluid to thus enhance the propelling action of the first flow. 
     The gaseous fluid of at least one of the flows can be constituted by compressed air. 
     The propelling step includes or can include advancing successive commodities of the series at spaced-apart intervals, and such method can further comprise the steps of monitoring a predetermined portion of the path and generating signals upon detection of commodities in the predetermined portion of the path. The introducing step of such method can include admitting into the path gaseous fluid in response to the signals and behind the respective commodities (as seen in the predetermined direction). 
     If the commodities are elongated rod-shaped articles (such as plain or filter cigarettes or filter rod sections) , the propelling step includes advancing the articles lengthwise. 
     If the path exhibits an arcuate section upstream of a first at least substantially straight section and downstream of a second at least substantially straight section (as seen in the predetermined direction), the introducing step can include admitting into the second at least substantially straight section of the path a stream of compressed gaseous fluid behind each of successive commodities of the series to thus promote the advancement of commodities into and along the arcuate section of the path. 
     If the commodities are elongated rod-shaped articles, the establishing step can include imparting to the path a configuration such that a rod-shaped commodity advancing along the path changes its direction of movement through a predetermined angle, e.g., an angle which is at least close to 90°. 
     Furthermore, the establishing step can include providing a path wherein the commodities advance from a first level to a second level, e.g., from a lower level to a higher level. Such advancement can take place while the commodities change the direction of their advancement (e.g., through 90° from a movement in a horizontal plane to a movement in a vertical plane). 
     Still further, the establishing step can include providing a path (e.g., a substantially L-shaped path) having at least one section wherein the commodities are propelled with a negligible play. 
     The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and the modes of assembling, installing and operating the same, together with numerous additional important and advantageous features and attributes thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The single Figure of the drawing is a partly schematic fragmentary elevational view of a transporting system which is designed for the transport of rod-shaped commodities and embodies one presently preferred form of the invention. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     The drawing shows a portion of a transporting system  1  which can be utilized in a production line serving to turn out filter cigarettes and including a filter rod maker (refer to the aforementioned U.S. &#39;007 patent to Greve) and a filter tipping machine (refer to the aforementioned U.S. &#39;008 patent to Oesterling et al.). The system  1  can be utilized to transport successive rod-shaped commodities  6  (such as filter mouthpieces or rod sections of six times unit length) from the discharge end of the filter rod maker to the magazine of the tipping machine. 
     The system  1  comprises a composite pneumatic conduit including a straight horizontal first section  14 , an arcuate intermediate section  2 , and a straight vertical third section  16 . These sections define an elongated arcuate path and are installed in the production line in such a way that successive commodities  6  (hereinafter called rod-shaped articles or articles for short) are caused to advance from the lower level  30  of the section  14  to the higher level  31  of the section  16  and to change the direction of their advancement through an angle of at least substantially 90° during transport through that portion ( 4 ) of the elongated path which is defined by the arcuate median conduit section  2 . 
     The cross-sectional area of the path portion defined by the conduit section  14  is round and its diameter only slightly exceeds the diameters of the articles  6 , and the same preferably applies, or can hold true, for the cross-sectional area of the path portion defined by the conduit section  16 . On the other band, the cross-sectional area of the path portion  4  defined by the arcuate median section  2  of the pneumatic conduit first gradually increases from that matching the cross-sectional area of the path portion defined by the section  14  to a considerably larger cross-sectional area midway between the sections  14 ,  16 , and thereupon gradually decreases to the cross-sectional area of the path portion defined by the section  16 . This ensures that an article  6  advancing in the path portion  4  defined by the arcuate section  2  can change its orientation without undergoing any, or any appreciable, deformation. 
     The section  14  is separably or permanently but sealingly affixed to the adjacent end portion  10  of the arcuate median conduit section  2 , and the other end portion  12  of the section  2  is permanently or separably but sealingly affixed to the section  16 . 
     A source  7  of compressed gaseous fluid (e.g., a compressor or accumulator of any known design) discharges a first flow or stream of such fluid into the inlet  14   a  of the conduit section  14 . Such first flow propels successive articles  6  of a series of such articles into and within the conduit sections  14 ,  2 ,  16  and on to the magazine of the tipping machine. The manner in which successive spaced-apart articles  6  are fed into the conduit section  14  (to advance in the direction indicated by the arrow  8 ) is not shown in the drawing. 
     The flow of compressed air issuing from the source  7  and advancing in the path for the articles  6  toward and into the secton  16  can effectively propel successive articles into the path portion  4 . However, and since the cross-sectional area of the median region of the path portion  4  exceeds the cross-sectional area of the path portion in the section  14 , the propelling action of the flow of compressed gaseous fluid in the path portion  4  is much less pronounced. In addition, the flow of compressed gaseous fluid flowing from the section  14  into and within the section  2  must overcome the force of gravity acting upon the articles  6  advancing from the lower level of the conduit section  14  to the higher level of the conduit section  16 . 
     In order to assist the aforediscussed first flow of compressed gaseous fluid in predictable and rapidly propelling successive articles  6  from the section  14 , through the section  2  and into the section  16 , the transporting unit  1  comprises means  28  for intermittently admitting into the path for the articles  6  an additional or second flow of a compressed gaseous fluid whenever an article has advanced beyond a second inlet  29  controlled by the fluid admitting means  28 . 
     The admitting means  28  comprises of constitutes a normally closed open-and-shut valve having a gas-admitting port connected to the source  7  by a pipe  9  indicated by a phantom line. The valve  28  is responsive to signals generated by a sensor  18  which is installed in the discharge end of the conduit section  14  or in the adjacent receiving end  10  of the conduit section  2  and transmits a signal (e.g., an electric signal) via conductor means  20  whenever it detects the presence of an article  6  advancing toward the enlarged median part of the path portion  4 , i.e., the presence of an article downstream of the inlet defined by the valve  28 . 
     The conductor  20  transmits signals to a control circuit or regulating circuit  22  which controls a valve opening and closing device  26 . The latter opens the valve  28  when it receives a signal via conductor means  24 . 
     When an article  6  (which advances in the conduit section  14  in the direction indicated by the arrow  8 ) reaches the sensor  18 , the latter transmits a signal via conductor means  20  and the regulating circuit  22  actuates the device  26  via conductor means  24 . This causes the valve  28  to open and to permit compressed gaseous fluid (such as atmospheric air) to flow from the source  7 , via pipe  9  and into the path portion defined by the conduit section  14  or  2 . Thus, the article  6  which has initiated the generation of a signal at  18  is acted upon by a blast of compressed gaseous fluid in addition to the action of compressed gaseous fluid being admitted by the source  7  into the inlet  14   a  of the conduit section  14 . That portion of the path which receives the just discussed article  6  when the sensor  18  transmits a signal to the circuit  22  is dimensioned to snugly receive the article. This ensures that the article receives a pronounced impetus for advancement along the path portion  4  and into the conduit section  16 . In other words, additional gaseous fluid being admitted by the valve  28  compensates for leakage of fluid entering the path portion  4  via conduit section  14 ; such leakage is attributable to the fact that the cross-sectional area of the central part of the path portion  4 , for example the cross-sectional area designated by reference number  33 , considerably exceeds the cross-sectional area of an article  6 . 
     The pressure and quantity of additional flow of gaseous fluid entering the conduit including the sections  14 ,  2   16  via inlet controlled by the valve  28  can be readily selected in such a way that the additional flow compensates for the reduced propelling action of the first flow (from the source  7  directly into the inlet of the section  14 ) attributable to the ability of fluid of the first flow to bypass an article  6  in the arcuate path portion  4 , as well as for the fact that an article advancing in the section  2  must be lifted from the level of the section  14  to the level of the section  16  against the action of gravity. 
     It is clear that the transporting system  1  can comprise or cooperate with two discrete sources of gaseous fluid; for example, the source  7  can be utilized to supply gaseous fluid to the inlet  14   a  of the conduit section  14  or to the inlet controlled by the open-and-shut valve  28 , and a second source can be provided to supply gaseous fluid to the valve  28  or to the inlet  14   a . The gaseous fluid being supplied to the valve  28  and/or to the inlet  14   a  is but need not always be atmospheric air. 
     An advantage of the feature that the valve  28  is installed upstream of the arcuate section  2  of the composite pneumatic conduit including the sections  14 ,  2 ,  16  is that the additional flow which enters the composite conduit in response to opening of the valve  28  can reliably compensate for losses of fluid forming part of the first flow and for the need to raise successive articles  6  from the level of the section  14  to that of the section  16 . As already mentioned above, the trailing end of that article  6  which has initiated an opening of the valve  28  (via sensor  18 , regulating unit  22  and actuating device  26 ) is snugly received in the respective portion of the path when it is subjected to the action of additional flow of gaseous fluid entering the path via pipe  9  and valve  28 . 
     The sensor  18  and the regulating circuit  22  can be omitted if successive articles  6  enter the conduit section  14  at predetermined (fixed) intervals. The normally closed valve  28  is then set to open at a predetermined frequency in order to admit a second or additional flow of gaseous fluid whenever the trailing end of an article  6  enters a path portion at a predetermined distance from and downstream of the inlet controlled by the valve  28 . In other words, the frequency at which the valve  28  opens can be properly related to (synchronized with) the frequency at which the conduit section  14  receives articles  6  from a filter rod making machine or from another source of rod-shaped commodities. 
     The provision of the valve  28  is preferred if the conduit section  14  does not receive articles  6  at a fixed frequency and/or when it is desired or necessary to admit additional gaseous fluid when an article  6  is located at a predetermined distance from and downstream of the valve  28  (irrespective of the frequency at which successive articles of a series of such articles enter the inlet  14   a  of the conduit section  14 ). Such mode of operation contributes to an even more predictable transport of successive articles  6  from the level of the conduit section  14  into the conduit section  16 . 
     The arcuate conduit section  2  can be omitted if the section  16  is coaxial with the section  14 ; the admission of additional gaseous fluid (via valve  28  or an equivalent inlet-controlling device) then serves the purpose of ensuring that the articles entering the section  16  advance therein at a preselected speed or within a preselected speed range. The primary purpose of the section  2  (i.e., of the path portion  4 ) is to ensure that the articles  6  are not damaged while they are caused to change the direction and/or level of their advancement from a source to a processing station. 
     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 that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of the above outlined contribution to the art of pneumatic transporting apparatus for cigarettes or the like and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the appended claims.