Patent Publication Number: US-6213283-B1

Title: Apparatus for transferring rod-like articles

Description:
This invention relates to transferring rod-like articles, particularly transferring rows of cigarettes for subsequent packing in a cigarette packing machine. 
     In order to achieve higher speeds in cigarette packing machines it is desirable that as many parts of the machine as possible should operate continuously rather than intermittently. In particular it is desirable that the conveyor in which the groups of cigarettes are assembled into bundles for subsequent wrapping should run continuously. The present invention is particularly but not exclusively concerned with transfer apparatus suitable for feeding cigarettes to such a conveyor, particularly from a hopper or other region in which the cigarettes are substantially stationary. 
     According to one aspect of the invention apparatus for transferring rod-like articles includes means for supplying articles to a plurality of adjacent delivery positions arranged in a row, rotary conveyor means including means for receiving articles from said positions, the rotary conveyor means comprising a plurality of planetary wheels each having receiving means defining individual article positions; an annular carrier for translating said wheels along a path extending adjacent said row so that said receiving means receives articles from said positions; and a sun wheel having means defining grouped article positions each of which is adapted to receive articles in successive layers from said planetary wheels. 
     Preferably, the adjacent delivery positions are defined by a series of vanes defining rows in the outlet of a hopper, and each planetary wheel is provided with at least one set of flutes defining the individual article positions, the number of flutes in the or each set corresponding to the number of rows in the outlet of the hopper. 
     Preferably, the sun wheel is in the form of a drum, having pockets defining the grouped article positions, and the planets are mounted in a carrier and are geared to the outside of the sun wheel and to a fixed ring gear, so that rotation of the drum causes the planets to rotate on their own axes, and also drives the planet carrier round the drum. The gearing is such that the or each set of flutes on each planet coincides in position with a set of outlet vanes on the hopper when the articles are to be received, and also co-operates with the pockets on the drum, when they are to be delivered. 
     Preferably, each pocket on the drum is sufficiently deep to accommodate a plurality of layers of articles, each layer corresponding to one set of flutes on the planets, and the arrangement is such that each pocket receives a row of articles from one of the planet wheels, which is laid down into the pocket as the planet wheel passes it. 
     In a preferred embodiment of the invention, there is at least one set of three hopper delivery positions, and the pockets are three layers deep, the position and gearing of the planet wheels being such that successive layers of articles are transferred into each pocket, by the planet wheels, as they pass by each hopper delivery position. 
    
    
     Some embodiments of the invention will now be described by way of example, with reference to the accompanying drawings, in which: 
     FIG. 1 is a schematic view of a first type of hopper, planet and drum arrangement; 
     FIG. 2 is a cross-section through a hopper planet and drum pocket of the machine shown in FIG. 1; 
     FIG. 3 is a schematic view corresponding to the view of FIG. 1, for an alternative construction having two drums; 
     FIG. 4 is a similar schematic view, but showing an arrangement having two sets of three hoppers; 
     FIG. 5 is a cross-section through a differential drive system for the planet wheels; 
     FIG. 6 is a perspective view of a drum assembly of the same general kind as shown in FIG. 1; 
     FIG. 7 is an axial view of a part of the mechanism of FIG. 6; 
     FIG. 8 is a cross-section taken along the lines Z—Z of FIG. 7; 
     FIG. 9 is a partial perspective view showing the planet wheels of a drum assembly having 18 planet wheels; 
     FIG. 10 is a partial elevational view of the machine of FIG. 9, showing the transfer sequence in more detail; and 
     FIG. 11 is a cross-section through the hopper, planet assembly and drum pocket of the machine of FIGS.  9  and  10 . 
    
    
     FIG. 1 shows a first embodiment of the invention, in which cigarettes are fed from three hoppers,  2 ,  4  and  6 , each of which has internal vanes defining a row of seven adjacent outlet positions. Each row of cigarettes is received by a row of flutes on a planetary wheel  8 ,  10 ,  12  etc, the planetary wheels being mounted on a rotating carrier and driven around a central drum  20 , by gearing which connects the planet wheels to the drum. The drum is provided with pockets  22 ,  24  etc, each of which is three rows deep, so as to accommodate the output from three of the planet wheels. 
     Describing the operation of this embodiment in more detail, it will be seen from a consideration of the position of planet wheels  8  and  10  in the drawing, that the planet wheel  10  has just passed the hopper  2 , and has received a row of cigarettes from it, which are then held in flutes  28  on its surface by suction, until it rotates to a position in which it is above the leading edge of pocket  22 . At this stage, the suction on each of the flutes is successively cut off, so that the cigarette will be deposited into the pocket  22  in a row which will fall (or preferably be guided, as described below) into the bottom of the pocket. A suitable arrangement for controlling the suction is shown in more detail in WO95 21771. 
     Subsequently, as the drum continues to rotate, the pocket  22  will arrive at a position beneath a further planet wheel, in the position indicated at  16 , which has previously collected a row of cigarettes from hopper  4 , and this will result in a second row being transferred into the pocket, as indicated at  24 . Similarly, the third row of cigarettes, taken from the hopper  6 , will have been added to the pocket to completely fill it, by the time it reaches position  26 . 
     In this arrangement there are six pockets in the drum, and 14 fluted planets equi-spaced around it. The planets are geared to the outside of the drum and to a fixed ring gear, and suitable gearing is used to ensure that the flutes on each planet always match the rows defined by the hopper vane, and deliver the cigarettes to the pockets on the drum in suitable positions. 
     It will be appreciated that any number of pockets on the drum can be catered for, by use of a suitable number of planets and gear ratios. 
     The drawing also illustrates the use of guides  30 , mounted on the carrier between the planet wheels, which are suitably shaped to guide the cigarettes from the hopper output onto the flutes of the planetary wheels, as for example, indicated at  32 , and also to guide the cigarettes from the flutes of the planet wheel, into each pocket, as indicated at  34  on the drawing. 
     Referring to FIG. 2, each planet wheel  8 ,  10  etc is mounted by means of a shaft  36  in the planet carrier  38 , and a gear  40  on the other end of the shaft engages with a ring gear  42  on one side, and a sun gear  44  on the other side. A vacuum pipe  46  in the shaft  36  communicates with the flutes  48  of the planet wheel, so that cigarettes can be taken from the hopper  50 , and supplied to the pocket  52  on the drum. 
     Subsequently, a plunger  54  transfers the bundle formed in the pocket  52 , into a collating box  56  for transfer onto a pocketed belt, chain or drum so that it can be transported to the next stage of the operation. 
     FIG. 3 shows an arrangement in which there are two drums  58  and  60 , each of which is fed by a set of three hopper outputs  62 ,  64 ,  66 , and  68 ,  70 ,  72 . This arrangement reduces the risk of starvation in the hopper vanes, by allowing the speed of cigarettes in each hopper vane to be reduced by 50%. In this arrangement, the first drum  58  lays up cigarettes in pockets A on the drum, and the bundles are then transferred axially into a belt system  74  which also passes around the second drum  60 , where alternate pockets B are filled, and the belt then transfers the completely filled sets of pockets onto the next stage of the process at the regions  76 , before returning to the drum  58 . It will be appreciated that the belt system  74  could also be replaced by a pocketed chain, for example. 
     Another possible arrangement for reducing the speed of cigarettes in the vanes of the hopper is illustrated in FIG. 4, in which there is a single drum  78 , having two sets of hoppers A, B, C and X, Y, Z. Each planet wheel  80 ,  82 ,  84  etc has two sets of flutes in its periphery, one of which is geared to meet with hoppers A, B, &amp; C, whilst the other is geared to meet with hoppers X, Y, Z. With suitable gearing, this enables hoppers A and X to supply cigarettes for the first layer in each pocket, hopper B and Y to supply cigarettes for the second layer, and hoppers C and Z to supply cigarettes for the third layer in the pocket, as will be clear from the drawing. The arrangement is such that each set of flutes on each planet wheel delivers to alternate pockets on the drum, and in the combination shown there are 16 pockets on the drum and 18 equi-spaced planet wheels. 
     As an alternative it will be appreciated that if there were three sets of hopper outlets and each planet had three sets of flutes then each of the three layers to be received in a pocket could be identified uniquely with a flute set, i.e. there could be three sets of flutes on each planet respectively with 7, 6 and 7 cigarette positions for a standard  20  collation. Of course, in order to provide room for nine hopper outlets the drum would need to be relatively large in order to avoid having the outer hopper outlets too far displaced from a vertical position. 
     FIG. 5 illustrates a differential drive speed system, which helps to prevent a cigarette from jamming between the parts of the mechanism. 
     This happens because each planet wheel is effectively rolling around the pitch diameter of the hoppers, and thus the relative motion of each planet to a cigarette in the hopper is momentarily zero. In addition, the planet is also rolling around the pitch diameter of the drum so that relative motion of the planet to the drum is also momentarily zero. 
     However, the cigarettes in the hoppers are spaced apart to allow for clearances such as the width of the vane material, and in a typical case, the effective cigarette spacing is 9 mm around the planet, resulting in the cigarettes being transferred to the drum at 9 mm spacing. Without vanes in the pockets on the drum, this amount of clearance build up could allow the cigarettes to jam and get misaligned. 
     In order to prevent this happening, the planet wheel can be run at a higher surface speed than the surface speed of the drum so that the spacings close up, for example, for ten cigarette spacings of 9 mm on the planet (pitch length 90 mm) drum rotation should equal 10 cigarette spacings of 8 mm.=80 mm. In order to achieve this, as shown in FIG. 5, the planet carrier  86  is formed with a number (typically, three) of axially extending mounting shafts  88  equi-spaced around its circumference, which are journalled in planet gears  90  running around the sun gear  92 . A ring gear  94 , mounted externally of the planet gears, engages with the planet gears and carries a further ring gear  96 , having a larger internal diameter, and a planet driving gear  98  is driven in turn by the gear  96 . 
     This arrangement allows the planets  100  to run at a higher surface speed than the drum  102 , thus causing the spacing of the cigarettes to close up. 
     Thus in the example shown, for spacings closed from 9 mm to 8 mm, the speed difference is 12½%. 
     Referring to FIG. 6, a typical drum construction is shown in which there are 8 pockets, and it will be seen that the drum also carries assemblies of plungers  104  which operate to transfer the cigarettes from the pockets  106  of the drum, into the pockets of a conveyor (not shown) which runs between a pair of flanges  108  and  110  on the outer end of the drum. 
     As will be clear from FIGS. 6 and 7, the drum pocket of the embodiment shown includes vanes  114  to properly locate the individual cigarettes received from the flutes of the planet wheels, but in order to ensure that the cigarettes are properly laid down in each position, without jamming, it is necessary to provide a retractable support in each pocket, which moves lower into the pocket as the drum rotates, and as successive layers are laid into the pocket. Accordingly, the support mechanism  112  is driven by a retractable link mechanism  116  in such a way that a pair of support arms  118  can be progressively lowered into the pocket, as the drum rotates. As will be appreciated from a consideration of the diagrammatic views of FIG. 1 or  4 , for example, the same effect could also be achieved by means of a circular “ramp” like profile extending around the drum, so as to form an inwardly spiralling surface. 
     The perspective view of FIG. 9 illustrates in somewhat more detail, how plate-like guide members  120  are mounted between adjacent planet wheels. As will be clear from the drawing, the upper leading corner  122  of the guide  120  is so shaped that it helps to guide the cigarettes out of the hopper onto the flutes of the planetary wheel, as the drum rotates in a counter-clockwise direction, while the lower leading corner  124  of the guide acts to support the cigarettes as they leave the flutes of the wheel, and enter the guide vanes  114  of the pocket. 
     FIG. 10 illustrates in more detail, the transfer path of each row of cigarettes from the bottom of the hopper, into the drum pocket, for an arrangement having 18 planet wheels and 8 pockets. 
     Starting from the righthand side of the drawing, a lifter assembly  130  is radially extended to support incoming cigarettes in the pocket  132 , and a pivoted guide member  134  attached to the guide plate  120  is rotated in an anti-clockwise direction, in preparation for cigarette feed from the adjacent planet wheel  136 . The next anti-clockwise position  138  of the planet wheel shows the guide  134  in the open position, and cigarettes are beginning to enter the flutes of the planet wheel, from the hopper  140 . 
     In the next counter-clockwise position the lifter assembly  142  is beginning to retract back towards the centre of the sun wheel, as cigarettes from the flutes of the planet  144  are beginning to enter the vanes of the pocket  147 , so that they will be supported in the correct alignment, in the continually increasing gap between the lifter and the planet wheel. 
     The next counter-clockwise planet wheel  146  is shown in the process of receiving a row of cigarettes from the following hopper  148 , and thus, at the next planet wheel position  150 , the pocket  152 , which already contains a first row of cigarettes, supported by the partially retracted lifter  154 , receives a second row of cigarettes from the overlying planet wheel. The third row is added in a similar fashion by the planet wheel  156 , from the hopper  158 , and thus by the time the pocket has reached the position  160  at the lefthand side of the drawing, it contains three rows of cigarettes, and the lifter  162  has been retracted out of engagement with the lowest row of cigarettes. At the same time, the inner guide  134  is rotated back in a clockwise direction to retain the cigarettes in the pockets. 
     Referring to the cross-sectional drawing of FIG. 11, this shows the mechanism in a position in which the lifter  130 , pocket  132 , planet wheel  136 , and hopper  140  are aligned with one another, and it will be seen that the planet assembly  136  is fixed to a carrier plate  162 , which runs on a bearing assembly  164  mounted on a fixed frame  166  of the machine. The planet itself comprises a shell  168  mounted on a shaft  170 , journalled in bearings  172  and  174  in the planet assembly  136 , and driven around by planet gear  176  which is engaged between a fixed ring gear  178  and a sun gear  180  on the rear periphery of the sun assembly itself. This in turn is journalled on bearings  182 ,  184 , on the central shaft  186  of the machine. In the typical arrangement shown, the pitch circles for the planet gear, the ring gear, and the sun gear are 99 mm, 990 mm and 792 mm, and there are 8 pockets at a spacing of 45° and 18 planets at a spacing of 20°. 
     This results in a carrier speed of {fraction (4/9)}ths times the sun speed, and a planet speed of 10 times the carrier speed. When the sun wheel rotates 45°, i.e. one pocket pitch, the carrier has advanced {fraction (4/9)}th times 45°, i.e. 20° or one planet position. In this way, the pockets are suitably aligned to receive cigarettes from the next planet wheel, each time they have moved through 45° (see FIG.  10 ). 
     As illustrated in the drawing, suction for the flutes of the planet wheel is applied via a manifold  198  and co-operating ports  200  in the shell  168   
     FIG. 11 also illustrates the arrangement of the collation plunger  188  having fingers  190  which are arranged to eject the collation  192  from the pocket, into a collation mouthpiece  194  when the pocket is full, the operation being controlled by a fixed plunger cam  196 .