Patent Publication Number: US-10779562-B2

Title: Method of emptying trays filled with rod-shaped articles of the tobacco industry

Description:
The subject of the invention is a method of emptying trays filled with rod-shaped articles of the tobacco industry. 
     Tobacco factories produce a variety of smoking articles. Both finished and semi-finished products fabricated at different stages of production can generally be described as rod-shaped articles, which can be transported on conveyors or in trays. Commonly used in the tobacco industry are plastic trays, which are used for all types of rod-shaped articles, including cigarettes, cigarillos, cigars, and filter rods. The plastic trays are in the shape of a cuboid without two walls, i.e. they have four walls. The plastic trays are rigid and serve to temporarily store and transport rod-shaped articles in tobacco factories. The rod-shaped articles stored in the trays are emptied into the mass flow supplied to machines that perform technical operations in order to fabricate the smoking articles. 
     U.S. Pat. No. 8,100,621 discloses a device and method for the consecutive emptying of trays filled with rod-shaped articles, the device comprising the means for conveying rod-shaped articles incoming from trays, as well as a chute connecting the outlet of articles with the means of transport, such that a channel is created, through which the stream of rod-shaped articles can be moved towards the receiving device. 
     European patent No. EP1020126 describes a method and device for transporting cigarettes, in which cigarettes are transported using trays from a processing machine to a hopper, where they are unloaded, and then transported using discharge conveyors to a packer hopper. According to the invention, the hopper unit is divided by dividers into several adjacent channels. Each of the channels has a support element, which moves together with the cigarettes from top to bottom of the hopper, where the dividers are tear-shaped and built like a comb with its protruding ribs inserted into the notches of the supporting elements in the form of a flat comb. The vertical side wall of the hopper on the side of the packer is moveable, and moves together with the conveyor that conveys the cigarettes towards the packer hopper. The length of the dividers is shorter than the height of the hopper, where the shortest divider is that closest to the moveable side wall, and the length of the subsequent dividers gradually increases. The end of the longest divider is at a significant distance from the discharge conveyor. A layer of cigarettes is thus transported to the hopper, and the height of the layer corresponds to that of the moveable side wall. The height of the layer is maintained by the moving side wall until it reaches the hopper. All known methods and devices for unloading trays are characterized by the common principle that the discharge of individual channels to the discharge conveyor is gravitational due to the removal of individual elements supporting the cigarettes from the bottom in individual channels or groups of channels. This involves the risk of jamming, or deformation of the rod-shaped articles. 
     The subject of the invention is a method of emptying trays filled with rod-shaped articles of the tobacco industry, which consists of the following steps: trays designated for emptying are conveyed to an input area of a hopper containing adjacent channels separated by dividers; the rod-shaped articles are transferred from the trays to the channels of the hopper using support plates; the channels of the hopper are filled with the rod-shaped articles; the support plates are retracted from the channels of the hopper; the channels of the hopper are successively emptied into a chute adapted to move between the outlets of the channels of the hopper; finally, the rod-shaped articles are transferred from the channels of the hopper and through the chute onto the discharge conveyor moving towards the receiving device. The method is further characterized in that during emptying at least one channel of the hopper, the hopper moves linearly in the direction opposite to that in which the rod-shaped articles are transported by the discharge conveyor; and after the channel has been completely emptied, the hopper moves in the direction concurrent with the direction in which the rod-shaped articles are transported by the discharge conveyor, until the outlet of the next channel filled with rod-shaped articles is aligned with the inlet of the chute, whereas the hopper moves at a variable velocity when moving in the direction concurrent with that in which the rod-shaped articles are transported by the discharge conveyor. 
     Furthermore, the method is characterized in that when the hopper is moving in the direction concurrent with the direction in which the rod-shaped articles are transported by the discharge conveyor, the velocity of movement of the hopper reaches zero. 
     Furthermore, the method is characterized in that when the hopper is moving in the direction concurrent with the direction in which the rod-shaped articles are transported by the discharge conveyor, the velocity of movement of the hopper decreases until it achieves a position in which the outlet of the next channel filled with rod-shaped articles is aligned with the inlet of the chute. 
     Furthermore, the method is characterized in that when the hopper is moving in the direction concurrent with the direction in which the rod-shaped articles are transported by the discharge conveyor, the hopper moves at a first velocity, and after receiving a signal from an accumulation sensor that rod-shaped articles have accumulated near the inlet of the chute, the hopper moves at a second velocity, whereas the second velocity is lower than the first velocity, until it achieves a position in which the outlet of the next channel filled with rod-shaped articles is aligned with the inlet of the chute. 
     Furthermore, the method is characterized in that when the hopper is moving in the direction concurrent with the direction in which the rod-shaped articles are transported by the discharge conveyor, the hopper moves at first velocity, and after receiving a signal from the accumulation sensor indicating lack of accumulated rod-shaped articles near the inlet of the chute, the hopper moves at a second velocity, where the second velocity is higher than the first velocity, until it achieves a position in which the outlet of the next channel filled with rod-shaped articles is aligned with the inlet of the chute. 
     Furthermore, the method is characterized in that the direction of movement of the hopper changes, after receiving a signal from the channel fill sensor indicating a change in the extent to which the hopper is filled with rod-shaped articles, from the direction opposite to that in which the rod-shaped articles are transported by the discharge conveyor, to the direction concurrent with the direction in which the rod-shaped articles are transported by the discharge conveyor. 
     Furthermore, the method is characterized in that the direction of movement of the hopper changes, after receiving a signal from the channel fill sensor indicating that the next channel of the hopper is aligned with the inlet of the chute, from the direction concurrent with the direction in which the rod-shaped articles are transported by the discharge conveyor, to the direction opposite to the direction in which the rod-shaped articles are transported by the discharge conveyor. 
     Furthermore, the method is characterized in that the chute, in order to empty the rod-shaped articles from at least one channel of the hopper, moves linearly in the direction opposite to the direction in which the rod-shaped articles are transported by the discharge conveyor, until all the rod-shaped articles have been emptied from the channel. 
     Furthermore, the method is characterized in that the chute, after receiving a signal from the channel fill sensor indicating that the rod-shaped articles have been emptied from the channel of the hopper, starts to move linearly in the direction concurrent with the direction in which the rod-shaped articles are transported by the discharge conveyor, until the next channel of the hopper is aligned with the inlet of the chute. 
     Furthermore, the method is characterized in that the chute moves linearly in the direction opposite to the direction in which the rod-shaped articles are transported by the discharge conveyor at an instantaneous velocity equal to the velocity of movement of the hopper. 
     Furthermore, the method is characterized in that the chute moves in the direction concurrent with the direction in which the rod-shaped articles are transported by the discharge conveyor at an instantaneous velocity lower than the velocity of movement of the hopper. 
     Furthermore, the method is characterized in that the chute moves in the direction concurrent with the direction in which the rod-shaped articles are transported by the discharge conveyor with a velocity equal to the velocity at which the rod-shaped articles are transported by the discharge conveyor. 
    
    
     
       The object of the invention was shown in detail in preferred embodiment in a drawing in which: 
         FIG. 1  presents a front view of a station for emptying a filled tray before loading a filled tray. 
         FIG. 2  presents a front view of the station for emptying a filled tray after loading the filled tray. 
         FIG. 3  presents the process of transferring rod-shaped articles from trays to channels of a hopper. 
         FIG. 4  presents a front view of the station for emptying a filled tray after rod-shaped articles have been transferred to the channels of the hopper, with the movement of a chute back to the starting position. 
         FIG. 5  presents a front view of the station for emptying a filled tray at the moment when the outer channel of the hopper is being emptied. 
         FIG. 6  presents a front view of the station for emptying the filled tray at the moment when the outer channel of the hopper is being emptied, and the hopper is moving to adjust to the position of the chute. 
         FIG. 7  presents a front view of the station for emptying the filled tray at the moment when the next filled channel of the hopper is aligned with the entrance to the chute. 
         FIG. 8  presents a front view of the station for emptying the filled tray at the moment when the next channel of the hopper is being emptied. 
         FIG. 9  presents a front view of the station for emptying the filled tray at the moment when the next filled channel of the hopper has been emptied, and the hopper and chute have momentarily stopped to change the direction of movement. 
         FIG. 10  presents a front view of the station for emptying the filled tray at the moment when the channel of the hopper is being emptied, and both the hopper and the chute with accumulated rod-shaped articles are moving to adjust positions. 
         FIG. 11  presents a front view of the station for emptying the filled tray at the moment when the channel of the hopper is being emptied, and both the hopper and the chute without accumulated rod-shaped articles are moving to adjust positions. 
         FIG. 12  presents a front view of the station for emptying the filled tray at the moment when the next filled channel of the hopper is aligned with the entrance to the passage. 
         FIG. 13  presents a graph of the changes in position of the chute and the hopper throughout the full emptying cycle of the hopper. 
         FIG. 14  presents a graph of the changes in position of the chute and the hopper throughout part of the emptying cycle encompassing emptying of one channel. 
         FIG. 15 a    presents a graph of the changes in position of the hopper throughout a part of the emptying cycle encompassing emptying of one channel, with a momentary deceleration of the hopper. 
         FIG. 15 b    presents a graph of the changes in position of the hopper throughout a part of the emptying cycle encompassing emptying of one channel, with a momentary acceleration of the hopper. 
         FIG. 15 c    presents a graph of the changes in position of the hopper throughout a part of the emptying cycle encompassing emptying of one channel, with the hopper at a momentary stop. 
         FIG. 15 d    presents a graph of the changes in position of the hopper throughout a part of the emptying cycle encompassing emptying of one channel, with the hopper moving at variable velocity. 
     
    
    
     For better understanding, the subject of the invention is illustrated in the figures, where  FIGS. 1 through 11  present the individual stages of emptying channels and a tray according to the embodiment of the invention, with continuous movement of a discharge conveyor, and  FIGS. 12 through 14   c  present the position of the chute and the hopper at the subsequent stages of the cycle for emptying the hopper. 
       FIG. 1  shows a station  1  for emptying a filled tray. The station  1  has a hopper  2 , a discharge conveyor  19 , and a chute  20 . The hopper  2  has a left side wall  3 , a right side wall  4 , a rear wall  5 , and dividers  6  that divide the space of the hopper  2  into vertical channels  7 . The channels  7  may be of equal or different width.  FIG. 1  depicts two specific channels  7 : an outer channel  7   a ; and a channel  7   g , which is emptied as the last one. In the embodiment, the outer channel  7   a  is half as wide as the remaining channels  7 . The hopper  2  also has a transfer element  8  mounted slideable relative to the dividers of the hopper  2 , and which is provided to move the mass flow of rod-shaped articles in the individual channels of the hopper  2  downwards. The transfer element  8  has many support plates  9  which are adapted to support the mass flow of rod-shaped articles through the channels  7  and through the outer channel  7   a , where each channel  7  has two support plates  9 . The support plates  9  are situated horizontally and perpendicular to the rear wall  5  of the hopper  2 . The support plates  9  are mounted to supports that pass through slits  11  in the rear wall  5  of the hopper  2 , as well as to a supporting element  12  that slides horizontally on a track  13  in the direction perpendicular to the rear wall  5  of the hopper  2 . The support plates  9  of the transfer element  8  may be inserted into the channels  7  through the upper notches  14  near the inlets  15  of the channels. The support plates  9  of the transfer element  8  may be retracted from the channels  7  through the lower notches  16  near the outlets  17  of the channels. In the inlets  15  are additional dividers  18  situated at the mid-width of the channels  7 . 
     Below the hopper  2  is a discharge conveyor  19 . Between the hopper  2  and the discharge conveyor is a sliding chute  20  adapted to move along the discharge conveyor. The sliding chute  20  is provided to move the mass flow of rod-shaped articles from the channels  7  to the discharge conveyor  19 , which discharges the rod-shaped articles received from the channels  7  of the hopper  2  in direction T, where the chute  20  has a separate drive and is adapted to move relative to the discharge conveyor  19 . Above the inlet  21  to the chute  20  is a passage  22 , which is formed by belts  23 ,  24 . 
       FIG. 2  presents the station  1  for emptying the filled tray just after the filled tray  10  has been placed thereon, where the sliding cover  28 , which is part of the element for transporting the tray, and which keeps the rod-shaped articles R in the tray  10 , has not yet been retracted. Channel  7   g  is still partially filled. The tray  10  waits in this position until all the channels  7  are at least partially emptied. After the sliding cover  28  has been retracted, the rod-shaped articles R stored in the tray  10  fall onto the support plates  9  of the transfer element  8 . After the rod-shaped articles R have fallen out, the transfer element  8  begins moving downward, so that the rod-shaped articles R are led into the channels  7 , as shown in  FIG. 3 . 
     The tray  10  can be made of plastic or cardboard, and can be either four- or five-walled. The tray may also be made of other suitable material. Five-walled cardboard trays are usually less solid than four-walled trays, and usually intended for single use. 
       FIGS. 3 and 4  present the subsequent steps of the process, in which all the rod-shaped articles R from channel  7   g  are passed into the chute  20  through the passage  22 , and the absence of rod-shaped articles R in the passage  22  is detected by the accumulation sensor  27 . It is also possible to use the signal from one sensor to determine the extent to which the channel is filled with rod-shaped articles, as well as the accumulation of rod-shaped articles in the passage  22 . The signal of the absence of rod-shaped articles in the passage  22  is the signal for the chute  20  to move in the direction G 1  concurrent with the direction T in which the rod-shaped articles R are transported by the discharge conveyor  19 , where the velocity Vt with which the mass flow is conveyed on the conveyor and the velocity Vg of the movement of the chute are equal. This velocity Vg of movement of the chute  20  ensures constant level of the rod-shaped articles in the inlet  21  while the chute  20  is in motion. 
     Once the inlet  21  of the chute  20  is under the outlet  17   a  of the outer channel  7   a  ( FIG. 5 ), the outer support plate  9   a  is displaced by the actuator  26  in the direction T concurrent with the direction in which the rod-shaped articles R are transported by the discharge conveyor, after which the rod-shaped articles R from the channel  7   a  begin to flow through the passage  22 , and join the mass flow on the discharge conveyor  19 , which moves with the velocity Vt. When the rod-shaped articles R are being moved from the outer channel  7   a , the support plates  9  of the transfer element  8  are released in a direction perpendicular to that T of discharge. After the support plates  9  have been retracted, the rod-shaped articles R in the channels  7  rest on the belt  23  or other supporting element ( FIG. 6 ). After all the rod-shaped articles R have been moved from channel  7   a , which is detected by the channel fill sensor  25 , the chute  20  moves with a velocity of Vg, which is equal to the velocity of the conveyor Vt, in direction G 1 , and the hopper, with linear velocity Vs, which is higher than the velocity of the movement of the chute Vg, moves in direction S 1  for faster alignment of the inlet  21  of the chute  20  with the outlet  17   b  of channel  7   b . ( FIG. 7 ). After the alignment of the inlet  21  of the chute  20  with the outlet  17   b  of channel  7   b , the hopper  2  and the chute  20  stop for a moment to change the direction of movement, as shown in  FIG. 7 . Then, the hopper  2  moves in the direction S 2  with the velocity Vs, and the chute  20  moves with it at the same velocity in direction G 2 , which is parallel to S 2 , where the outlet  17   b  and inlet  21  are at a fixed position relative to each other ( FIG. 8 ). After the channel fill sensor  25  sends a signal indicating that channel  7   b  has been completely emptied of rod-shaped articles R, the hopper  2  and chute  20  momentarily cease movement in order to change the direction of the movement ( FIG. 9 ).  FIG. 10  presents the movement of the hopper  2  in the direction S 1  in order to align the outlet  17   c  of a channel  7   c  with the inlet  21  of the chute  20 , which also moves in the direction G 1  with the velocity Vg. The hopper  2  moves at a velocity Vs higher than that of Vg with which the chute  20  moves. When aligning the outlet  17   c  of the channel  7   c  with the inlet  21  of the chute  20  and at the simultaneous opening via the belt  23  of channel  7   b , the rod-shaped articles Ra may accumulate at the outlet of channel  17   b  and the inlet  21  of the chute  20 , and be clipped by the divider  6  of the moving hopper  2  and the belt  24 . The accumulation of rod-shaped articles Ra may be caused by the force exerted by the mass of rod-shaped articles R in channel  7   c , or by the elasticity of the material from which the rod-shaped articles R are made. At the opening of the outlet  17   c  of channel  7   c  via the belt  23 , the rod-shaped articles that fall first may bounce off of the rod-shaped articles already in the chute  20  and cause accumulation near the inlet  21 . Upon detection of such accumulation of rod-shaped articles Ra by the accumulation sensor  27 , the movement of the hopper  2  and/or the chute  20  will be momentarily halted and/or slowed, while the discharge conveyor  19  continues to operate. Momentary halting or deceleration of the hopper  2  and/or the chute  20  will allow the rod-shaped articles Ra near the outlet  17   b  to be removed by the discharge conveyor  19 . After receiving a signal from the accumulation sensor  27  that the rod-shaped articles Ra have been removed from the outlet of channel  17   b  by the discharge conveyor  19 , the hopper  2  will continue moving in the direction S 1  with velocity Vs, together with the chute the  20 , which will move parallel in direction G 1  with velocity Vg, as shown in  FIG. 11 . Also possible is an embodiment in which, during each movement of the hopper  2  in direction S 1  and the chute  20  in direction G 1  in order to align the inlet  21  of the chute  20  with the outlet  17  of channel  7 , momentary halting or deceleration of the hopper  2  and/or the chute  20  is forced by a propulsion program of the emptying station  1 , without the intervention of an accumulation sensor  27 . Upon alignment of the outlet  17   c  of channel  7   c  with the inlet  21  of the chute  20  ( FIG. 12 ), the hopper  2  and chute  20  are momentarily halted in order to change the direction of movement, at which point the rod-shaped articles R are emptied from channel  7   c.    
     The other channels  7  of the hopper  2  are emptied in the same way. 
     When aligning the next channel  7   c  with the chute  20 , the hopper  2  can make a movement of various parameters depending on the nature of the accumulation, the properties of the rod-shaped articles, the operating velocities of the trays used in the system, and other similar parameters in the process of emptying and transporting the rod-shaped articles. It is also possible to apply a non-linear change in the motion of the hopper  2 , whose instantaneous velocity can increase or decrease at certain points. The instantaneous velocity of the hopper  2  can change stepwise or continuously. The hopper  2  can also move in reverse, with multiple changes in the direction of motion. Furthermore, it is possible to adjust the acceleration so as to improve the accumulation of rod-shaped articles inside the channels  7  of the hopper  2 . 
     It should be noted here that the nature of the movement of the hopper  2 , as determined by its parameters, such as instantaneous velocity, acceleration, and velocity-change points, can change over time. The parameters can also be set to apply only for a single operation cycle. In case of changes in motion parameters, it is possible to use presets, as well as apply adaptive changes over time, for example in response to changes in the velocity of the discharge conveyor  19 . 
     The shift in location of the chute  20  and the hopper  2  throughout the entire cycle of emptying of the hopper  2  is presented in  FIG. 13 . The solid line shows the path S G  traversed by the chute  20  as a function of time t, while the dashed line S s  shows the path traversed by the hopper  2  as a function of time t. In the time interval from t 0  to t 2 , the chute  20  performs a reverse motion in the direction G 1  of the starting position S Gmax , from the last channel  7   g  back to the first  7   a . Simultaneously, in the time interval from t 0  to t 1 , the rod-shaped articles are emptied from the tray  10  to the channels  7  of the hopper  2 ; and in the time interval from t 1  to t 2 , the hopper  2  moves to the starting position indicated on the graph S Smax . In the time interval from t 2  to t 3 , channel  7   a  of the hopper  2  is emptied, while both the chute  20  and hopper  2  simultaneously move with the same velocity in direction G 2 , until channel  7   a  has been completely emptied of rod-shaped articles. At point t 3 , the hopper  2  and the chute  20  momentarily come to a halt, and begin reverse motion in direction G 1 , until the next outlet  17   b  of filled channel  7   b  of the hopper  2  is aligned with the inlet  21  of the chute  20 , which is indicated on the graph by t 4 . At point t 4 , the chute  20  and the hopper  2  momentarily come to a halt, and change their direction of movement from G 1  to G 2 . Then, in the time interval from t 4  to t 5 , channel  7   b  of the hopper  2  is emptied, while both the chute  20  and hopper  2  simultaneously move with the same velocity in direction G 2 , until channel  7   b  has been completely emptied of rod-shaped articles. This cycle of movement of the hopper  2  and the chute  20  repeats until all rod-shaped articles R have been emptied from the last channel  7   g  of the hopper  2  at t 15 .  FIG. 14  shows a graph of the changes in position of the chute  20  and the hopper  2  throughout part of the emptying cycle including emptying of one channel. In the time between t 5 , and t 6 , the chute  20  and hopper  2  move in directions S 1  and G 1  in order to align the filled channel  7   c  of the hopper  2  with the inlet  21  of the chute  20 . At this stage, the velocity of the chute  20  is adapted to the velocity at which the rod-shaped articles R are transported by the discharge conveyor; and the distance traversed by the hopper  2  is therefore increased by the distance traversed by the chute  20 . This means that the instantaneous velocity of the hopper  2  is higher than the velocity of the chute  20  from t 5  to t 6 . At point t 6 , the directions of the chute  20  and hopper  2  change to S 2  and G 2 . In the time interval from t 6  to t 7 , the rod-shaped articles R are emptied from channel  7   c , and the chute  20  and hopper  2  move in directions S 2  and G 2  at the same velocity until all rod-shaped articles R have been emptied from channel  7   c.    
       FIGS. 15 a  to 15 d    present examples of the movement of the hopper in the time interval from t 5  to t 7 . In the time interval from t 5  to t 6 , the velocity of the hopper  2 , after being completely emptied, moves in the direction concurrent with that of T in which the rod-shaped articles R are transported by the discharge conveyor  19  until the outlet of the next channel filled with rod-shaped articles is aligned with the inlet  21  of the chute  20  t 6 . The velocity of movement of the hopper  2  in the direction concurrent with that of S 1  in which the rod-shaped articles R are transported by the discharge conveyor  19  changes over time. The variable movement of the hopper  2  relative to the chute  20  is intended to eliminate damage to the rod-shaped articles Ra which may occur due to clipping of the rod-shaped articles Ra by the divider  6  of the moving hopper  2  or the belt  24 . Examples of changes in the movement of the hopper  2  relative to the chute  20  are presented in  FIG. 15 a -15 d   , where the velocity of the hopper decreases stepwise in  FIG. 15 a   , increases stepwise in  FIG. 15 b   , momentarily decreases to zero in  FIG. 15 c   , and changes continuously over time in  FIG. 15   d.    
     LIST OF TERMS 
     
         
           1  station for emptying filled tray 
           2  hopper 
           3  left side wall of hopper 
           4  right side wall of hopper 
           5  rear wall of hopper 
           6  dividers 
           7  channels of hopper 
           7   a  outer channel 
           7   b  channel of hopper 
           8  transfer element 
           9  support plates 
           9   a  outer support plate 
           10  tray 
           11  vertical slits 
           12  support element 
           13  track 
           14  upper notches 
           15  channel inlets 
           16  lower notches 
           17  channel outlets 
           17   a - 17   g  channel outlets 
           18  additional dividers 
           19  discharge conveyor 
           20  sliding chute 
           21  chute inlet 
           22  passage 
           23  belt 
           24  belt 
           25  channel fill sensor 
           26  actuator 
           27  accumulation sensor 
           28  sliding cover 
         Ra accumulated articles 
         R rod-shaped articles 
         S G  path of chute 
         S S  path of hopper 
         Vs velocity of hopper 
         Vt velocity of discharge conveyor 
         Vg velocity of chute