CONTROL APPARATUS FOR BAR-SHAPED ARTICLES This invention rel ates to a
control apparatus for bar-shaped articles. More particularly, the invention relates to a control apparatus for cigarettes. In the known art a control operation for the purpose of checking the soundness of filter or filter-less cigarettes is effected by feeding a control air stream along the longitudinal axis of the cigarettes. This is done while the cigarettes are being transferred, transversely to their axis, by a rotary conveyor interposed between two further conveyors coaxial and rigid with them, and supporting ducts forming part of a pneumatic circuit. The control operation is effected by bringing two such ducts up to 0 the opposing ends of each cigarette so that it becomes incorporated into said pneumatic circuit. This circuit comprises pressure measurement means which in the case of a defective cigarette indicate an abnormal pressure and 0 provide a resultant expulsion command. The main condition which has to be satisfied to obtain correct control of the individual cigarettes is that tile connection bet ween the ends of each cigarette and the two ducts is perfectly sealed. If it is not, any inflow of atmospheric air or outflow of control fluid through the connection regions between the cigarette and the pneumatic circuit results in an alteration in the result of the control operation and the consequent possibility of expelling sound cigarettes or, alternatively, the non-expulsion of defective cigarettes. To obviate these drawbacks, devices are known which for the connection between the pneumatic circuit and the cigarette ends use cap- shaped elastic connection elements mounted in an airtight manner on the tubular ends of said ducts. For the control operation, the outer walls, provided with a through hole, of two of such connection elements are brought into contact with the opposing ends of each cigarette. The pressure exerted by the cigarettes is sufficient to cause elastic deformation of the connection elements, which then adhere via their respective outer walls to the ends of the cigarettes. However, a minimum imperfection in one of said ends or a deposit of dust particles on the walls of the connection elements is sufficient to impair the isolation of the pneumatic circuit from the atmosphere, to consequently falsify the result of the control operation. The object of the present invention is to provide a.control apparatus able to obviate the described drawbacks of the known art, ie an apparatus in which the connection means between the pneumatic circuit and the end of the cigarettes provide a perfect seal. This object is attained according to the present invention by a control apparatus for bar-shaped articles, comprising a conveyor provided with seats for containing said articles for the purpose of transferring said articles transversely to their axis along a determined path, a pneumatic circuit being provided for controlling the soundness of said articles during said transfer 41 and comprising ducts substantially coaxial to said seats and associated with at least one end of each of said seats, characterised by comprising a tubular sleeVe mounted coaxially on each duct, means for axially moving said sleeve on its duct with a to-and-fro movement, an elastic connection element of substantially tubular shape associated with and coaxial to each duct and mounted at a first end on said duct and fixed at its second end to the relative tubular sleeve, said connection element in proceeding from its first to its second end being divided into a first part extending towards said seat and a second part turned back inside out over the first part so that said first part defines in its interior a substantially cylindrical cavity coaxial to said seat and of diameter just less than the diameter of a cigarette, and provided with a mouth in the region in which it turns back into the second part, said mouth being mobile, under the action of said axial movement means, between a position in which it is disengaged from the article housed in said seat and a position in which the end of said article is iiiselted into said cavity. The invention is described hereinafter with reference to the accompanying drawings, which represent a non-limiting embodiment thereof, and in which: Figure 1 is a partly sectional front view of an apparatus constructed in accordance with the present invention; and Figures 2 and 3 show a detail of Figure 1 to an enlarged scale, under two different operating conditions. In Figure 1, the reference numeral 1 indicates overall a control 4 apparatus for bar-shaped articles, comprising a conveyor in the form of a roller 2, rotating about a horizontal axis. In the case under consideration, in which the articles are cigarettes, the control apparatus 1 forms part of a filter fitting machine, not shown. The roller 2 is provided with equidistant peripheral seats 4 (of which only one is shown in the figure) extending parallel to the axis 3, and each able to contain a cigarette 5 provided with filter 6. The cigarettes are retained in their respective sets 4 by suction means of known type, not shown, communicating with the outside via substantially radial ducts 7. At the two sides of the roller-2, and coaxial and rigid therewith, there are provided two identical discs 8 and 9, arranged symmetrical to each other. Each of the two discs 8 and 9 is provided peripherally, in positions corresponding with each seat 4 of the roller 2, with a through aperture 10 into which there is slidingly inserted a duct 11 coaxial to the seat 4 and having a diameter substantially equal to that of a cigarette 5. A tubular sleeve 12 is mounted coaxially on a substantially intermediate part of the duct 11 and is slidable thereort. The sleeve 12 is subjected to the action of axial movement means, being connected, by a pin 13 normal to the axis 3, to an idle roller 14 which when the disc 8 (9) rotates runs in a groove 15 of a drum cam 16 which is fixed coaxially to the roller 2. That wall 17 of each disc 8, 9 which faces away from the roller 2 1 - 5 is provided, in a Position corresponding with the mouths of the ducts 11, with a circular groove 18 facing the mouth of a duct 19 provided in a fixed block 20 adhering to the wall 17. The ducts 19 associated with the two discs 8 and 9 are connected to a pump means of known type (not shown), able to generate a positive or negative pressure via the pneumatic circuit comprising the fixed ducts 19, the circular groove 18 and the ducts 11. A block 21 schematically represents a device for controlling and measuring the pressure within said pneumatic circuit. With each duct 11 there is associated a connection element 22 of elastic material and of substantially tubular shape, its purpose being to connect (as will be apparent hereinafter) each cigarette transferred by the roller 2 into the pneumatic circ-uit (see also Figures 2 and 3). Startin.d from that end which is seal-mounted on Ihe outer cylindrical surface of the free end of the duct 11, the connection element 22 comprises a first part 23 extending towards the seat 4 and a second part 24 which is turned back inside out over the first and is fixed to the outer cylindrical surface of the sleeve 12 mobile under the control of the cam 16. The part 23 defines in its interior a cylindrical seat or cavity 25 which is coaxial to the corresponding seal 4 arid has a diameter just less than the diameter of a cigarette 5, and of which the mouth, facing the seat 4, is formed by a portion 26 which connects together the two parts 23 and 24. The connection element 22 is fixed by iiisertii3g As two ringshaped ends into corresponding annular grooves 27 arid 28 provided - 6 in the duct 11 and sleeve 12 respectively. When in use, the transfer roller 2 for the cigarettes 5 and the two discs 8 and 9, forming the support means for the ducts 11, are rotated about the axis 3 by motor means, not shown, forming part of said filter fitting machine.
The seats 4 are connected by the radial ducts 7 to said suction source, to retain in their interior the cigarettes 5 provided with the filter 6. On feeding cigarettes 5 into the seats 4 of the rollet. 2 (in a position aii,:,rularly spaced from the position shown in Figure 1) the sleeves 12 and the relative connection elements 22 are in a position in which they are disengaged from the ends of the cigarettes 5. This situation is shown for a single cigarette end in Figure 2. As the roller 2 and discs 8 and 9 rotate, the two sleeves 12 associated with each seat 4 slide axially on the ducts 11 under the control of the movement means associated with the cam 16, so that as a result of the particular shape of the groove 15 they approach those ends of the ducts 11 facing the seat 4. As a result of the mutual approach of the two grooves 27 and 28 to which the connection element 22 is fixed, the mouth 26 approaches one end of the respective seal 4 so that one end of the cigarette 5 housed in said seat is progressively inserted into the cavity 25, which communicates with said pneumatic circuit. This insertion, which terminates when the position shown in Figure 3 and known as the control position is reached, is effected without connection element 22 sliding on the cylindrical surface 1 of the cigarette. Under these conditions the cigarette 5 is incorporated perfectly airtight into the pneumatic circuit comprising the fixed duct 19, the groove 18, the ducts 11 and the device 20, from which a command is fed for ejecting the cigarette if the pressure measured by it differs from a predetermined fixed value. The particular form of the connection elements 22 together with the elasticity and deformability characteristics of their constituent material allows extremely delicate treatment of the cigarette during the control operation. On termination of this operation, as the rotation of the roller 2 continues the two tubular sleeves 12, under the control of tile cam 16, separate from the seat 4 to release the cigarette ends from the connection elements 22 so as to enable the cigarette to be transferred to further conveyor means, not shown.
1 is 8 CLAIMS
1. A control apparatus for bar-shaped articles, comprising a conveyor provided with seats for containing said articles for the purpose of transferring said articles transversely to their axis along a determined path, a pneumatic circuit being provided for controlling the soundness of said articles and comprising ducts substantially coaxial to said seats and associated with at least one end of each of said seats, characterised by comprising a tubular sleeve mounted coaxially on each duct, means for axially moving said sleeve on its duct with a to-and-fro movement, an elastic connection element of substantially tubular shape associated with and coaxial to each duct and mounted at a f irst end on said duct and f ixed at its second end to the relative tubular sleeve, said connection element in proceeding from its first to its second end being divided into a first part extending towards said seat and a second part turned back inside out over the f irst part so that said first part defines in its interior a substantially cylindrical cavity coaxial to said seat and of diameter just less than the diameter of a cigarette, and provided with a mouth in the region in which it turns back into the second part, said mouth being mobile, under the action of said axial movement means, between a position in which it is disengaged from the article housed in said seat and a position in which the end of said article is inserted into said cavity.
2. A control apparatus for bar-shaped articles substantially as described with reference to the accompanying drawings.
Published 1991 at The Patent Office. State House. 66/71 High Holborn. LondonWC I R47P. Further copies may be obtained from Sales Branch, Unit 6. Nine Mile Ploint, Cwrnrelinfacb. Cross Keys. Newport. NP1 7HZ. Printed by Multiplex techniques ltd. St Mary Cray, Kent.
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