Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B51/00—Devices for, or methods of, sealing or securing package folds or closures; Devices for gathering or twisting wrappers, or necks of bags
  • B65B51/10—Applying or generating heat or pressure or combinations thereof
  • B65B51/18—Applying or generating heat or pressure or combinations thereof by endless bands or chains
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
  • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
  • B29C65/18—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
  • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
  • B29C65/18—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools
  • B29C65/24—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools characterised by the means for heating the tool
  • B29C65/30—Electrical means
  • B29C65/32—Induction
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/01—General aspects dealing with the joint area or with the area to be joined
  • B29C66/05—Particular design of joint configurations
  • B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
  • B29C66/11—Joint cross-sections comprising a single joint-segment, i.e. one of the parts to be joined comprising a single joint-segment in the joint cross-section
  • B29C66/112—Single lapped joints
  • B29C66/1122—Single lap to lap joints, i.e. overlap joints
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
  • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
  • B29C66/43—Joining a relatively small portion of the surface of said articles
  • B29C66/431—Joining the articles to themselves
  • B29C66/4312—Joining the articles to themselves for making flat seams in tubular or hollow articles, e.g. transversal seams
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/80—General aspects of machine operations or constructions and parts thereof
  • B29C66/81—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps
  • B29C66/816—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the mounting of the pressing elements, e.g. of the welding jaws or clamps
  • B29C66/8161—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the mounting of the pressing elements, e.g. of the welding jaws or clamps said pressing elements being supported or backed-up by springs or by resilient material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/80—General aspects of machine operations or constructions and parts thereof
  • B29C66/82—Pressure application arrangements, e.g. transmission or actuating mechanisms for joining tools or clamps
  • B29C66/822—Transmission mechanisms
  • B29C66/8221—Scissor or lever mechanisms, i.e. involving a pivot point
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/80—General aspects of machine operations or constructions and parts thereof
  • B29C66/82—Pressure application arrangements, e.g. transmission or actuating mechanisms for joining tools or clamps
  • B29C66/824—Actuating mechanisms
  • B29C66/8244—Actuating mechanisms magnetically driven
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/80—General aspects of machine operations or constructions and parts thereof
  • B29C66/83—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools
  • B29C66/834—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools moving with the parts to be joined
  • B29C66/8351—Jaws mounted on rollers, cylinders, drums, bands, belts or chains; Flying jaws
  • B29C66/83511—Jaws mounted on rollers, cylinders, drums, bands, belts or chains; Flying jaws jaws mounted on rollers, cylinders or drums
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/80—General aspects of machine operations or constructions and parts thereof
  • B29C66/83—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools
  • B29C66/834—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools moving with the parts to be joined
  • B29C66/8351—Jaws mounted on rollers, cylinders, drums, bands, belts or chains; Flying jaws
  • B29C66/83521—Jaws mounted on rollers, cylinders, drums, bands, belts or chains; Flying jaws jaws mounted on bands or belts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/80—General aspects of machine operations or constructions and parts thereof
  • B29C66/84—Specific machine types or machines suitable for specific applications
  • B29C66/849—Packaging machines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/90—Measuring or controlling the joining process
  • B29C66/93—Measuring or controlling the joining process by measuring or controlling the speed
  • B29C66/934—Measuring or controlling the joining process by measuring or controlling the speed by controlling or regulating the speed
  • B29C66/93451—Measuring or controlling the joining process by measuring or controlling the speed by controlling or regulating the speed by controlling or regulating the rotational speed, i.e. the speed of revolution
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/90—Measuring or controlling the joining process
  • B29C66/94—Measuring or controlling the joining process by measuring or controlling the time
  • B29C66/944—Measuring or controlling the joining process by measuring or controlling the time by controlling or regulating the time
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B11/00—Wrapping, e.g. partially or wholly enclosing, articles or quantities of material, in strips, sheets or blanks, of flexible material
  • B65B11/06—Wrapping articles, or quantities of material, by conveying wrapper and contents in common defined paths
  • B65B11/28—Wrapping articles, or quantities of material, by conveying wrapper and contents in common defined paths in a curved path, e.g. on rotary tables or turrets
  • B65B11/30—Wrapping articles, or quantities of material, by conveying wrapper and contents in common defined paths in a curved path, e.g. on rotary tables or turrets to fold the wrappers in tubular form about contents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B19/00—Packaging rod-shaped or tubular articles susceptible to damage by abrasion or pressure, e.g. cigarettes, cigars, macaroni, spaghetti, drinking straws or welding electrodes
  • B65B19/02—Packaging cigarettes
  • B65B19/22—Wrapping the cigarettes; Packaging the cigarettes in containers formed by folding wrapping material around formers
  • B65B19/223—Wrapping the cigarettes; Packaging the cigarettes in containers formed by folding wrapping material around formers in a curved path; in a combination of straight and curved paths, e.g. on rotary tables or other endless conveyors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
  • B29C66/71—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the composition of the plastics material of the parts to be joined
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/80—General aspects of machine operations or constructions and parts thereof
  • B29C66/81—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps
  • B29C66/812—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the composition, by the structure, by the intensive physical properties or by the optical properties of the material constituting the pressing elements, e.g. constituting the welding jaws or clamps
  • B29C66/8126—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the composition, by the structure, by the intensive physical properties or by the optical properties of the material constituting the pressing elements, e.g. constituting the welding jaws or clamps characterised by the intensive physical properties or by the optical properties of the material constituting the pressing elements, e.g. constituting the welding jaws or clamps
  • B29C66/81261—Thermal properties, e.g. thermal conductivity, thermal expansion coefficient
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/80—General aspects of machine operations or constructions and parts thereof
  • B29C66/81—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps
  • B29C66/812—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the composition, by the structure, by the intensive physical properties or by the optical properties of the material constituting the pressing elements, e.g. constituting the welding jaws or clamps
  • B29C66/8126—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the composition, by the structure, by the intensive physical properties or by the optical properties of the material constituting the pressing elements, e.g. constituting the welding jaws or clamps characterised by the intensive physical properties or by the optical properties of the material constituting the pressing elements, e.g. constituting the welding jaws or clamps
  • B29C66/81262—Electrical and dielectric properties, e.g. electrical conductivity
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/80—General aspects of machine operations or constructions and parts thereof
  • B29C66/83—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools
  • B29C66/834—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools moving with the parts to be joined
  • B29C66/8351—Jaws mounted on rollers, cylinders, drums, bands, belts or chains; Flying jaws
  • B29C66/83521—Jaws mounted on rollers, cylinders, drums, bands, belts or chains; Flying jaws jaws mounted on bands or belts
  • B29C66/83523—Cooperating jaws mounted on cooperating bands or belts and moving in a closed path
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/80—General aspects of machine operations or constructions and parts thereof
  • B29C66/83—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools
  • B29C66/834—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools moving with the parts to be joined
  • B29C66/8351—Jaws mounted on rollers, cylinders, drums, bands, belts or chains; Flying jaws
  • B29C66/83531—Jaws mounted on rollers, cylinders, drums, bands, belts or chains; Flying jaws jaws mounted on chains

Definitions

• the present invention relates to a machine for wrapping products.
• the present invention relates to a continuous cellophaning machine for wrapping a packet of cigarettes in a respective sheet of transparent heat- seal material, to which the following description refers purely by way of example .
• continuous cellophaning machines for example of the type disclosed by EP-972704-A1, normally comprise a wrapping wheel having a number of seats, in each of which a respective packet of cigarettes is applied with a respective sheet of wrapping material, which is subsequently folded about the packet to form a tubular wrapping which is subsequently stabilized by heat sealing.
• each seat on the wrapping wheel with a respective sealing head fitted to the wrapping wheel and movable between a rest position and a work position in which the sealing head contacts the respective tubular wrapping.
• Wrapping wheels of the type described above are relatively complex, expensive and heavy, on account of the larger number of sealing heads and respective actuating devices housed on the wheel .
• the present invention also relates to a method of wrapping products.
• Figure 1 shows a schematic elevation of a preferred embodiment of the machine according to the present invention
• Figure 2 shows a larger-scale elevation of a detail in Figure 1/
• Figure 3 shows a section along line III-III in Figure 2;
• Figure 4 shows a larger-scale elevation of a further detail of the Figure 1 machine
• Figure 5 shows a larger-scale elevation of a variation of a detail in Figure 1.
• Number 1 in Figure 1 indicates as a whole a machine for wrapping packets 2 of cigarettes in respective sheets 3 of heat-seal wrapping material, in particular, sheets of polypropylene or similar.
• Machine 1 comprises a wrapping wheel 4, which rotates continuously about a respective horizontal axis 5 perpendicular to the Figure 1 plane, and has a number of peripheral seats 6.
• Each seat 6 receives a respective packet 2 and a respective sheet 3 of wrapping material at an input station SI, and feeds respective packet 2 and respective sheet 3 of wrapping material along a wrapping path PI and a subsequent stabilizing path P2 to an output station S2.
• Machine 1 also comprises a sealing device 9, which in turn comprises a number of sealing members 10, each having a respective known sealing head 11, which is heated by means of a respective known electric resistor
• Sealing device 9 also comprises a belt conveyor 12, which has an endless flexible belt 13 supporting sealing heads 11 on its outer face 14.
• the number of sealing members 10 equals the number of peripheral seats 6, so that each peripheral seat 6 operates at all times with the same sealing member 10, thus simplifying adjustment and set-up of machine 1.
• Each sealing member 10 is fed by belt 13 in time with a respective wrapping 7 and along a path P3 parallel to path P2, so that each sealing head 11 is applied to respective tubular wrapping 7 for a given length of time and so heat seals ' tubular wrapping 7. More specifically, path P3 forms a portion of an endless path P4, along which sealing heads 11 are fed cyclically by the continuous movement of belt 13.
• paths PI, P2, P3 are substantially arcs of a circle with a common center at axis 5.
• Conveyor 12 also comprises a guide device 15 for feeding belt 13 along endless path P4 and, in particular, along curved portion P3.
• Guide device 15 comprises three end pulleys 16, 17, 18 having respective axes of rotation parallel to axis 5 and about which belt 13 is wound.
• Pulleys 16 and 17 are located at opposite ends of path P3, while pulley 18 is located between pulleys 16 and 17 to define, with pulleys 16 and 17, the vertices of an isosceles triangle.
• pulley 17 is powered, and pulleys 16 and 18 are idle.
• the rotation speed of pulley 17 is such that the peripheral speed of sealing heads 11 along path P3 equals the peripheral speed of seats 6 along path P2.
• Guide device 15 also comprises a contoured track 19 of the same shape as path P4; and a connecting device 20 for connecting belt 13 to track 19.
• track 19 only extends along path P3.
• Contoured track 19 is defined by two identical facing grooves 21 formed in two parallel flat plates 22, which are perpendicular to axis 5 and located on opposite sides of belt 13.
• Connecting device 20 comprises a number of carriages 23 , each of which is supported by a respective appendix 24 fixed to the inner face 25 of belt 13, engages both grooves 21, and comprises a shaft 26 integral with respective appendix 24 and supporting, at opposite ends, two idle wheels 27, each rolling along respective groove 21.
• Each flat plate 22 is substantially rectangular and has a semicircular recess at and for avoiding interference with wrapping wheel 4.
• guide device 15 only comprises end pulleys 16 and 17 having respective axes of rotation parallel to axis 5, and about which belt 13 is wound.
• Each sealing head 11 is fitted to a respective substantially Z-shaped frame 28 comprising a central plate 29, which, at one end, has a lateral appendix 30 facing belt 13 and connected to belt 13 by a transverse hinge 31 parallel to the axes of pulleys 16 and 17, and, at the other end, has a lateral appendix 32 facing outwards and supporting respective sealing head 11 by a hinge 33 parallel to hinge 31.
• supporting frame 28 is connected to belt 13 by a connecting rod 34 enabling frame 28 to adapt to the varying curvature of belt 13.
• Each sealing head 11 substantially faces plate 29 of relative frame 28, and oscillates about relative hinge 33 between a work position ( Figure 5) in which sealing head 11 contacts a respective wrapping 7 traveling along path P2, and a rest position in which sealing head 11 does not contact a respective wrapping 7 traveling along path P2.
• the angular position of each sealing head 11 about relative hinge 33 is controlled, on one side, by an elastic thrust system 35 interposed between sealing head 11 and relative frame 28 and for maintaining sealing head 11 in said work position, and, on the other side, by a return device 36 for moving sealing head 11 towards relative plate 29 and into said rest position.
• Return device 36 comprises an armature 37 of ferromagnetic material, which is hinged at one end to relative sealing head 11 and engages in sliding manner two through holes 38 and 39 formed through relative plate 29 and belt 13 respectively.
• the portion of each armature 37 projecting inwards of belt 13 interferes, as armature 37 travels along path P3, with a magnetic field generated by a series of electromagnets 40 carried by plates 22 and which provide for moving sealing heads 22 away from wrappings 7.
• each sealing head 11 is applied to respective wrapping 7 is maintained constant alongside changes in the traveling speed of wrapping 7 along path P2, i.e. in the rotation speed of wrapping wheel 4, by varying the actual length of path P3 by means of electromagnets 40, which provide for adjusting the length of path P3 along which sealing heads 11 are applied to respective wrappings 7.
• Sealing heads 11 are made of material of relatively low thermal inertia and relatively high electric resistance, and are connected to one another in series by electric cables (not shown) to form a single endless turn 41 , along which flows an alternating electric current generated by induction by a variable magnetic field in turn generated by a known generating device 42 (shown schematically) connected magnetically to turn 41. Adjusting the intensity and/or frequency with which the variable magnetic field is varied regulates the intensity of the current circulating in turn 41, and therefore the working temperature of sealing heads 11.
• elastic system 35 and return device 36 are inverted, i.e. elastic system 35 keeps sealing head 11 in said rest position, and return device 36 moves head 11 into said work position.
• the actual length of path P3 is adjusted by means of electromagnets 40, which, in this case, however, exert a force of repulsion to restore sealing heads 11 from the rest to the work position.
• return device 36 is dispensed with, and the actual length of path P3 is adjusted, for each sealing head 11, by short- circuiting the ends of head 11 in controlled manner.
• each sealing head 11 is actively applied to respective wrapping 7 is maintained constant, alongside variations in the rotation speed of wrapping wheel 4, by deactivating sealing head 11 as opposed to moving it away from relative wrapping 7.

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=11438925

Family Applications (1)

Country Status (7)

Cited By (3)

Citations (4)

Family Cites Families (7)

• 2000
  • 2000-12-21 IT IT2000BO000735A patent/ITBO20000735A1/it unknown
• 2001
  • 2001-12-18 WO PCT/IT2001/000638 patent/WO2002049918A1/en not_active Application Discontinuation
  • 2001-12-18 US US10/450,644 patent/US20040065055A1/en not_active Abandoned
  • 2001-12-18 EP EP20010271307 patent/EP1351857A1/en not_active Withdrawn
  • 2001-12-18 AU AU2002219504A patent/AU2002219504A1/en not_active Abandoned
  • 2001-12-18 CN CNA018212077A patent/CN1482981A/zh active Pending
  • 2001-12-18 JP JP2002551432A patent/JP2004520235A/ja active Pending

Patent Citations (4)

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