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(11) | EP 1 780 127 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Packing wheel |
| (57) A packing wheel (1) for conveying products (2) for packing and sheets (S) of packing
material along an endless packing path (P) extending about a central axis (9); the
packing wheel (1) has a main shaft (12) coaxial with the central axis (9) and rotating
continuously about the central axis (9); a number of sectors (19), each of which is
connected idly to the main shaft (12), is mounted to rotate about the central axis
(9), and has a number of packing pockets (23) movable along the packing path (P) and
for receiving respective products (2); and a number of angular connecting devices
(24), each of which connects a respective sector (19) angularly to the main shaft
(12) to derive motion from the main shaft (12) and rotate the sector (19) about the
central axis (9) with a variable law of motion, so that the sectors (19) may have
different angular speeds at the same time.
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[0001] The present invention relates to a packing wheel for conveying products for packing along an endless packing path.
[0002] Though suitable for conveying any type of product, the packing wheel according to the present invention is particularly advantageous for use in the tobacco industry for conveying groups of cigarettes or packets of cigarettes on a cigarette packing machine, to which the following description refers purely by way of example.
[0003] Cigarette packing machines are known to employ wheels, each comprising a respective number of peripheral pockets for housing respective products defined by packets of cigarettes or groups of cigarettes for packing. A packing wheel of this sort is normally rotated in steps or continuously about a respective central axis to feed the pockets through a loading station, one or more packing stations, and an unloading station, at each of which, each pocket is normally stopped or advanced with a predetermined law of motion, e.g. at a given constant speed, for a given length of time to allow given product handling operations to be performed.
[0004] Stopping a step-rotated packing wheel poses no problem, the only real operating drawback being the length of the stops, which depends on the time taken to perform the longest operation.
[0005] In the case of a continuously-rotating packing wheel, each pocket is normally stopped or advanced with a given law of motion at each station by mounting each pocket on the packing wheel, so that it rotates, with respect to the packing wheel and under the control of a cam device, about a peripheral axis parallel to the central axis of rotation of the packing wheel. At each station, each pocket is first rotated about the peripheral axis of rotation in the same rotation direction as the packing wheel, and then in the opposite rotation direction to the packing wheel, so as to produce a temporary stoppage or, more generally speaking, a temporary variation in the travelling speed of the pocket.
[0006] The above solution normally has several drawbacks, owing to the peripheral axis of rotation of each pocket moving integrally with the packing wheel, thus resulting in a relatively short temporary variation in the travelling speed of the pocket, and owing to the fact that, during the variation in travelling speed, the position of each pocket with respect to the packing wheel and to the relative station continues changing.
[0007] It is an object of the present invention to provide a packing wheel designed to eliminate the aforementioned drawbacks, and which at the same time is cheap and easy to produce.
[0008] According to the present invention, there is provided a packing wheel as claimed in the accompanying Claims.
[0009] A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:
Figure 1 shows a schematic axial section of a preferred embodiment of the packing wheel according to the present invention;
Figure 2 shows a partly sectioned plan view, with parts removed for clarity, of the Figure 1 packing wheel.
[0010] Number 1 in the attached drawings indicates as a whole a packing wheel for conveying products, defined by groups 2 of cigarettes, and sheets S of packing material along an endless packing path P. Packing path P extends through a loading station 3, where groups 2 of cigarettes and sheets S of packing material are loaded onto packing wheel 1; an unloading station 4, where groups 2 of cigarettes wrapped or partly wrapped in sheets S of packing material are unloaded off packing wheel 1; and at least one packing station 5 located between loading station 3 and unloading station 4 in a travelling direction 6 of groups 2 along packing path P, and where each sheet S of packing material is folded about a respective group 2 of cigarettes by known packing devices not shown.
[0011] In the embodiment shown, loading station 3 for loading groups 2 of cigarettes coincides with the loading station of sheets S of packing material. In an alternative embodiment not shown, loading station 3 is separate from, and may be located up- or downstream from, the loading station of sheets S of packing material.
[0012] As shown in Figure 1, packing wheel 1 comprises a supporting plate or frame 7 connected to a fixed tubular column 8 coaxial with a central axis 9 and supporting for rotation, with the interposition of a bearing, an annular toothed packing wheel 10 coaxial with central axis 9 and meshing with a powered pinion 11 mounted for rotation through frame 7 and parallel to central axis 9. Packing wheel 1 also comprises a tubular main shaft 12, which is coaxial with central axis 9, is connected integrally at one end to toothed packing wheel 10, houses an initial portion of column 8, and is supported for rotation by column 8. The free end of main shaft 12 is fitted integrally with a box-shaped annular platform 13 coaxial with central axis 9 and comprising a cylindrical lateral wall 14 coaxial with central axis 9; a flat annular inner wall 15 perpendicular to central axis 9, facing frame 7, and connected integrally to main shaft 12; and a flat annular outer wall 16, which is perpendicular to central axis 9, is connected integrally to main shaft 12 by lateral wall 14 and inner wall 15, and is fitted in rotary manner to the outer surface of an intermediate portion of column 8. Outer wall 16, inner wall 15, lateral wall 14, and said intermediate portion of column 8, define an annular chamber 17 coaxial with central axis 9.
[0013] Column 8 comprises an end portion 18 projecting from platform 13 and idly supporting, with respective pairs of bearings, a number of independent radial sectors 19 arranged about central axis 9. The Figure 2 embodiment employs four sectors 19 (though this number may differ), and each sector 19 comprises an inner sleeve 20 coaxial with central axis 9 and fitted idly to end portion 18 of column 8; and a plate 21 extending outwards from sleeve 20 in a substantially radial direction with respect to central axis 9. Plates 21 face outer wall 16, lie in respective planes perpendicular to central axis 9 and at different distances from outer wall 16, and are fitted, at respective outer radial ends, with respective numbers of appendixes 22 parallel to central axis 9. Appendixes 22 of all sectors 19 are all equidistant from central axis 9, and equidistant from frame 7 along central axis 9.
[0014] In the Figure 2 embodiment, each sector 19 has three appendixes 22 (though this number may differ) equally spaced along sector 19 and about central axis 9; and each appendix 22 is fitted, on its surface facing radially outwards with respect to central axis 9, with a respective packing pocket 23 movable along endless packing path P and for housing a respective group 2 of cigarettes.
[0015] For each sector 19, packing wheel 1 comprises a respective angular connecting device 24 for angularly connecting sector 19 to main shaft 12. Each angular connecting device 24 comprises a pin 25 mounted for rotation through platform 13 and annular chamber 17, close to lateral wall 14, so as to oscillate, with respect to platform 13, about a respective axis 26 parallel to central axis 9. Pins 25 of connecting devices 24 are equally spaced about central axis 9 along a circle 27, and each pin 25 is fitted with a respective carriage 28 housed inside annular chamber 17.
[0016] The angular position of each carriage 28 about relative axis 26 is controlled by a cam device 29 comprising two superimposed cams 30 and 31, which are integral with column 8, extend in respective planes perpendicular to central axis 9 inside annular chamber 17, and have respective active profiles 32 and 33 extending about central axis 9. For each carriage 28, cam device 29 also comprises a cam follower device comprising a front cam follower roller 34 (with reference to travelling direction 6) connected to carriage 28 and rolling on active profile 32, and a rear cam follower roller 35 (with reference to travelling direction 6) connected to carriage 28 and rolling on active profile 33.
[0017] As shown more clearly in Figure 2, in addition to respective pin 25 and respective carriage 28, each angular connecting device 24 also comprises a respective articulated transmission 36 interposed between relative carriage 28 and relative sector 19, and which comprises a crank 37 integral with sector 19, extending radially outwards with respect to central axis 9, and rotating about central axis 9; a crank 38 integral with carriage 28, extending from carriage 28 towards column 8, and rotating about axis 26 of relative pin 25; and a connecting rod 39 interposed between the free ends of cranks 37 and 38.
[0018] In actual use, articulated transmission 36 converts the oscillations about relative axis 26 imparted to relative carriage 28 by cams 30 and 31 - which, with known modifications, may be replaced with a single cam - into corresponding oscillations of relative sector 19. By shaping active profiles 32 and 33, the law of motion (constant angular speed) imparted to each pin 25 by main shaft 12 can therefore be adjusted to impart any desired law of motion to each sector 19, while still keeping relative packing pockets 23 positioned perfectly radially with respect to central axis 9. Which law of motion may provide for arresting each sector 19 or advancing it at a different given constant angular speed from that of pins 25 at each of stations 3 to 5.
[0019] In connection with the above, it should be pointed out that, being connected idly to main shaft 12 and driven by relative articulated transmissions 36, sectors 19 are angularly independent, and their laws of motion are related solely by the shape of active profiles 32 and 33, which may be designed to accelerate sectors 19 as they travel between stations, thus drastically reducing downtime when moving between adjacent stations, and to keep one or more sectors 19 moving when one or mote other sectors 19 are arrested, for example, at relative other stations.
[0020] In other words, each connecting device 24 connects a respective sector 19 angularly to main shaft 12 independently of the other sectors 19, to rotate sector 19, independently of the other sectors 19, about central axis 9. Consequently, each connecting device 24 defines an actuator connected mechanically to a respective sector 19, to rotate sector 19 about central axis 9 independently of the other sectors 19.
[0021] In the embodiment shown, the laws of motion of sectors 19 are all the same, and are offset with respect to one another, on account of connecting devices 24 all operating with the same pair of cams 30 and 31. An alternative embodiment, not shown, comprises a number of pairs of cams, so that each connecting device 24 operates with its own pair of cams, and sectors 19 may have different laws of motion.
1. A packing wheel for conveying products (2) for packing and sheets (S) of packing material
along an endless packing path (P) extending about a central axis (9) of the packing
wheel (1); the packing wheel (1) comprising :
a main shaft (12) coaxial with the central axis (9) and rotating about the central axis (9);
a number of packing pockets (23) movable along the packing path (P) and for receiving the products (2) for packing and the sheets (S) of packing material;
a loading station (3) for loading the products (2) and where the products (2) are fed successively to the packing pockets (23);
a loading station for loading the sheets (S) of packing material and where the sheets (S) of packing material are fed successively to the packing pockets (23);
a packing station (5) where each sheet (S) of packing material is folded about a respective product (2); and
an unloading station (4) where the products (2), at least partly wrapped in the sheets (S) of packing material, are extracted from the packing pockets (23);
the packing wheel (1) being characterized by comprising:
a number of sectors (19) angularly independent of one another, and each of which is connected idly to the main shaft (12), is mounted to rotate about the central axis (9), and supports a number of packing pockets (23); and
a number of angular connecting devices (24), each of which connects a respective sector (19) angularly to the main shaft (12) to derive motion from the main shaft (12) and rotate the sector (19) about the central axis (9) with a variable law of motion and independently of the other sectors (19), so that the sectors (19) may have different angular speeds at the same time.
2. A packing wheel as claimed in Claim 1, wherein each angular connecting device (24)
comprises a carriage (28) rotating about an axis (26) of rotation, which is parallel
to the central axis (9) and movable with the main shaft (12) about the central axis
(9); cam means (29) for controlling rotation of the carriage (28) about the axis (26)
of rotation; and an articulated transmission (36) interposed between the carriage
(28) and the sector (19).
3. A packing wheel as claimed in Claim 2, wherein the articulated transmission (36) comprises
a first crank (37) integral with the sector (19) and rotating about the central axis
(9); a second crank (38) integral with the carriage (28) and rotating about the axis
(26) of rotation; and a connecting rod (39) interposed between the first and second
crank (37, 38).
4. A packing wheel as claimed in Claim 2 or 3, and comprising a platform (13) integral
with the main shaft (12); and a pin (25) coaxial with the axis (26) of rotation and
connecting the carriage (28) to the platform (13).
5. A packing wheel as claimed in Claim 2, 3 or 4, wherein the cam means (29) comprise
at least one fixed cam (30; 31) having an active profile (32; 33) extending about
the central axis (9); and at least one cam follower (34; 35) carried by the carriage
(28) and movable in contact with the active profile (32; 33).
6. A packing wheel as claimed in any one of Claims 1 to 5, wherein the axes (26) of rotation
of the sectors (19) are equally spaced about the central axis (9).
7. A packing wheel as claimed in any one of Claims 1 to 6, wherein the law of motion
of each sector (19) is the same as and offset with respect to the law of motion of
the other sectors (19).
8. A packing wheel as claimed in any one of Claims 1 to 6, wherein the law of motion
of at least one sector (19) differs from the law of motion of the other sectors (19).
9. A packing wheel as claimed in any one of Claims 1 to 8, wherein the loading station
(3) for loading the products (2) coincides with the loading station for loading the
sheets (S) of packing material.
10. A packing wheel as claimed in any one of Claims 1 to 8, wherein the loading station
(3) for loading the products (2) is separate from the loading station for loading
the sheets (S) of packing material.
11. A packing wheel for conveying products (2) for packing and sheets (S) of packing material
along an endless packing path (P) extending about a central axis (9) of the packing
wheel (1); the packing wheel (1) comprising :
a main shaft (12) coaxial with the central axis (9) ;
a number of packing pockets (23) movable along the packing path (P) and for receiving the products (2) for packing and the sheets (S) of packing material;
a loading station (3) for loading the products (2) and where the products (2) are fed successively to the packing pockets (23);
a loading station for loading the sheets (S) of packing material and where the sheets (S) of packing material are fed successively to the packing pockets (23);
a packing station (5) where each sheet (S) of packing material is folded about a respective product (2); and
an unloading station (4) where the products (2), at least partly wrapped in the sheets (S) of packing material, are extracted from the packing pockets (23);
the packing wheel (1) being characterized by comprising:
a number of sectors (19), each of which is connected idly to the main shaft (12), is mounted to rotate about the central axis (9), and supports a number of packing pockets (23); and
a number of actuators, each of which is connected mechanically to a respective sector (19) to rotate the sector (19) about the central axis (9) independently of the other sectors (19).
12. A packing wheel as claimed in Claim 11, wherein the main shaft (12) is fixed, and
the actuators are electric motors.
13. A packing wheel as claimed in Claim 11, wherein the main shaft (12) rotates about
the central axis (9), and the actuators are defined by angular connecting devices
(24), each of which connects a respective sector (19) angularly to the main shaft
(12) to derive motion from the main shaft (12) and rotate the sector (19) about the
central axis (9) with a variable law of motion and independently of the other sectors
(19), so that the sectors (19) may have different angular speeds at the same time.