US3797368A - Rotary bag making apparatus - Google Patents

Rotary bag making apparatus Download PDF

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Publication number
US3797368A
US3797368A US00165084A US3797368DA US3797368A US 3797368 A US3797368 A US 3797368A US 00165084 A US00165084 A US 00165084A US 3797368D A US3797368D A US 3797368DA US 3797368 A US3797368 A US 3797368A
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web
operating member
velocity
rotary
operating
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F Martelli
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    • 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
    • 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
    • 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
    • B29C66/70—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
    • B29C66/73—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 intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset
    • B29C66/739—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 intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset
    • B29C66/7392—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 intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of at least one of the parts being a thermoplastic
    • B29C66/73921—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 intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of at least one of the parts being a thermoplastic characterised by the materials of both parts being thermoplastics
    • 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
    • B29C66/8341—Roller, cylinder or drum types; Band or belt types; Ball types
    • B29C66/83411—Roller, cylinder or drum types
    • 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
    • B29C66/8341—Roller, cylinder or drum types; Band or belt types; Ball types
    • B29C66/83411—Roller, cylinder or drum types
    • B29C66/83415—Roller, cylinder or drum types the contact angle between said rollers, cylinders or drums and said parts to be joined being a non-zero angle
    • 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
    • B29C66/841—Machines or tools adaptable for making articles of different dimensions or shapes or for making joints of different dimensions
    • B29C66/8412—Machines or tools adaptable for making articles of different dimensions or shapes or for making joints of different dimensions of different length, width or height
    • 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
    • B29C66/851—Bag or container making machines
    • B29C66/8511—Bag making 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
    • B29C66/93431—Measuring or controlling the joining process by measuring or controlling the speed by controlling or regulating the speed the speed being kept constant over time
    • 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
    • B29C66/93441—Measuring or controlling the joining process by measuring or controlling the speed by controlling or regulating the speed the speed being non-constant over time
    • 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
    • B29C66/93—Measuring or controlling the joining process by measuring or controlling the speed
    • B29C66/939—Measuring or controlling the joining process by measuring or controlling the speed characterised by specific speed values or ranges
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B2155/00—Flexible containers made from webs
    • B31B2155/003—Flexible containers made from webs starting from tubular webs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B70/00—Making flexible containers, e.g. envelopes or bags
    • B31B70/74—Auxiliary operations
    • B31B70/92—Delivering
    • B31B70/94—Delivering singly or in succession
    • B31B70/946—Delivering singly or in succession the bags being interconnected
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T83/00—Cutting
    • Y10T83/465—Cutting motion of tool has component in direction of moving work
    • Y10T83/4693—With means to concurrently adjust flying frequency and retain flying speed of tool
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T83/00—Cutting
    • Y10T83/465—Cutting motion of tool has component in direction of moving work
    • Y10T83/4737—With tool speed regulator
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T83/00—Cutting
    • Y10T83/465—Cutting motion of tool has component in direction of moving work
    • Y10T83/4766—Orbital motion of cutting blade
    • Y10T83/4775—Tool speed varied within each orbital cycle

Definitions

  • ABSTRACT A rotary bag making apparatus of the type used to fabricate bags from a continuous web of thermoplastic film material is described.
  • the apparatus comprises a smooth feed cylinder driven at a constant velocity and adapted to feed the web material past an operating station and a sealing cylinder having a sealing member adapted to engage the web at spaced intervals during each revolution thereof, the web being heat sealed at such spaced locations between the smooth cylinder and the sealing member.
  • Means in the form of noncircular gearing are provided for rotating the sealing cylinder at a constant RPM with a cyclically varying instantaneous angular velocity.
  • the non-circular gearing means rotates the sealing cylinder through a drive shaft and means are provided for adjusting the angular position of the sealing cylinder. relative to that drive shaft whereby the instantaneous angular velocity of the sealing member at the momentof sealing engagement with the web may be adjusted.
  • Bag length is adjusted by changing the RPM of the sealing cylinder relative to the smooth feed cylinder, and means are provided for automatically and simultaneously adjusting the angular position. of the sealingcylinder on the drive shaft by a proper amount to maintain the velocity of the sealing member equal to the velocity of the web at the moment of engagement between the two.
  • SHEEI 2 [IF 3 INVENTOR. FflBP/Z/U a. MAV/PTEAA/ 1 ROTARY BAG MAKING APPARATUS
  • This invention relates to bag making apparatus and more particularly to a rotary apparatus designed to fabricate bags of thermoplastic film material.
  • Bags of the type here considered are generally made from a continuous web of double ply thermoplastic film by applying a thermoseal between the two plys and cutting the web at appropriate spaced intervals.
  • the length of the bag is determined by the spacing between such sealing and cutting operations along the web.
  • apparatusof the rotary type has been developed to perform the bag making operation hereunder consideration in a rapid and continuous manner.
  • the web is fed continuously at. high speed between a pair of rotary cylinders.
  • One of the cylinders (hereinafter referred to as the sealing cylinder) is provided with a heated sealing bar extending axially along its periphery and adapted to engage the web and press it against the opposing cylinder (hereinafter referred to as the smooth cylinder) in heat sealing relationship, one sealing operation being performed during each complete revolution of the sealing cylinder.
  • the cutting operation is performed synchronously with the sealing operation in a similar fashion by a rotary cutting blade preferably cooperative with a fixed blade, positioned at the other side of the web.
  • the opposing cylinders used for the sealing operation be traveling at which is their inability to adjust the bag length without a change in the size of the cylinders used.
  • the web since the web must be fed by the smooth cylinder without slippage or stretching and since the peripheral speed of that cylinder (the linear speed of the web) must be identical to the peripheral speed of the sealing bar on the sealing cylinder, the bag length always equals the circumference of the sealng cylinder regardless of rotary speed.
  • the opposing cylinders are precisely mechanically linked a change in bag length requires a replacement of both cylinders by a different matched pair of cylinders of different dimensions.
  • thermoplastic film easily stretchable and tearable natureof the film mateprecisely the same peripheral speed at the point of sealrial, particularly at the point of sealing.
  • high speed rotary sealing may subject the thermoplastic film to excessive stress resulting in seals of low quality and marred appearance.
  • the present invention comprises a bag making apparatus of the rotary type including means to feed a web of two ply thermoplastic film material continuously past a sealing and a cutting station.
  • the seal,- ing means at the sealing station comprises a smooth surfaced cylinder along the periphery of which the web is fed and a matching sealing cylinder provided with an extending sealing projection or bar on the surface thereof.
  • the cylinders are spaced from each other by a clearance only slightly greater than the projecting distance of the sealing bar.
  • the surface of the sealing cylinder never itself engages the. web material.
  • each time the sealing bar traverses the clearance between the cylinders the web is compressed between the heated sealing bar and the smooth cylinder surface, thereby to produce the required sealed joint.
  • the smooth cylinder over which the web is trained is driven at a constant angular velocityand determines the linear feed velocity of the web.
  • the sealing cylinder is driven through a gear train comprised of non-circular gears.
  • the gear train is here specifically disclosed as a pair of elliptical gears rotatablymounted on shafts positioned at their foci and spaced by a distance equal to their major axes.
  • the driving gear is rotated at a constant angular velocity and accordingly the angular velocity of the driven gear and its associated driven shaft varies during each complete rotation thereof between maximum and minimum values having a 180 phase displacement.
  • the sealing cylinder is operatively connected to the driven shaft for rotation therewith and is rotatably adjustable relative thereto. Accordingly, the sealing bar may be positioned to engage the web at any desired relative position of the meshing elliptical gears (i.e., at any desired instantaneous angular velocity of the sealing cylinder between the minimum and maximum values).
  • the length'of a bag i.e., the spacing between successive seals
  • the spacing between seals is directly proportional to the angular velocity ratio between the smooth cylinder and the driving elliptical gear. Accordingly, I provide means to vary that angular velocity ratio in accordance with the desired length of bag.
  • the sealing cylinder must be rotatably adjusted relative to the driven shaft to properly position the sealing bar for engagement of the web at the proper angular velocity.
  • the present invention provides such an adjustment mechanism and in accordance with the preferred embodiment here disclosed thatmechanism is adapted to automatically rotatably adjust the sealing cylinder in response to a given adjustment of the above noted angular velocity ratio.
  • FIG. 1 is a schematic illustration of the bag making apparatus showing the sealing and cutting stations
  • FIG. 2 is a schematic illustration of the sealing cylinder and smooth cylinder at the moment of sealing engagement with the elliptical drive gearing superimposed thereon, the sealing operation being accomplished at the minimum angular velocity;
  • FIG. 3 is a schematic illustration similar to FIG. 2 and showing the sealing engagement of the cylinders at the maximum angular velocity
  • FIG. 4 is a schematic illustration similar to FIG. 2 showing the sealing engagement of the cylinders at an arbitrary angular velocity between the minimum and maximum values;
  • FIG. 5 is a graphical illustration of an ellipse showing the major and minor'axes and the ordinate of the focus.
  • FIG. 6 is a schematic block diagram illustrating the control mechanisms for varying bag length.
  • the apparatus of the present invention is designed to operate on a continuously moving web of material at spaced intervals.
  • the invention is here specifically disclosed in connection with the fabrication of bags (commonly known as poly bags) from a web of thermoplastic features of material. It will be appreciated, however, that the important featureof the present invention are applicable to virtually any operation or work performed on a web at spaced intervals in a continuous manner.
  • the rotary apparatus for performing the above operations is shown schematically in FIG. 1.
  • the web material generally designated 10 is fed to the left inthe direction of arrow 12 over an infeed roll 14, past a sealing station generally designated 16 and a cutting station generally designated 18 and thence outwardly in the direction of arrow 20 over an outfeed roll 22.
  • the web 10 may be fed to the apparatus directly from the printing station.
  • the sealing operation is accomplished at sealing station 16 by means of a pair of matched cylinders 24 and 26 rotatably mounted on shafts 28 and 30, respectively.
  • Cylinder 24 (hereinafter referred to as the smooth cylinder) has a smooth outer surface of radius R1 and cylinder 26 (hereinafter referred to as the sealing cylinder) is provided on its outer surface 31 of radius R2 with a sealing projecton or bar 32 extending in the axial direction into the plane of the drawing along a generatrix of the cylinder 26 and projecting radially from surface 311 by a distance s.
  • Means are provided for heating the sealing bar 32 to a temperature sufficient to effect a good thermoseal.
  • the web it) is fed over the smooth cylinder-24 which is in turn rotated through shaft 28 at a constant speed.
  • the web is thus advanced linearly at a constant speed between cylinders 24 and 26.
  • the surface 31 of cylinder 26 is spaced from the surface of cylinder 24 by a distance slightly greater than the projecting width 5 of the sealing bar 32. Consequently, there is a slight clearance 34 (no direct contact) between the web and the outer surface 31 of sealing cylinder 26.
  • sealing bar 32 comes opposite cylinder 24, the web is compressively engaged between the heated bar 32 and the surface of cylinder 24, thereby to form a heat seal between the two plys extending generally transversely to the direction of web travel.
  • cutting station 18 comprises a pair of spaced rotatable stabilizing rolls 36 and 38 between which a fixed knife blade 40 is mounted.
  • a rotary perforating blade 42 is mounted on a cutting cylinder 44 in opposing relationship with fixed blade 40 and is adapted to cooperate therewith in shearing relationship.
  • the web 10 is fed overstabilizing rolls 36 and 38 and traverses the fixed blade 40.
  • the rotary blade 42 engages the web and cooperates to shearingly perforate the web in a direction generally transverse to its direction of travel.
  • the cutting cylinder 44 is driven through a shaft 46 which is mechanically linked, in a manner hereinafter described, to the seal- 3 ing cylinder such that the webv is perforated during each cycle at a location adjacent the sealing joint in the web.
  • the thus'sealed and perforated web is then moved over the outfeed roll 22 and may be conveyed in an appropriate manner to a packing station and/or an automatic separating mechanism in which the individual bags are separated along the perforated lines.
  • the length of web feed between seals is directly proportional to the angular velocity of the smooth cylinder 24.
  • the spacing between successive seals is directly proportional to theratio of the rates of complete rotations of cylinders 24 and 26 or (herein used-synonomously with seal spacing) W1 rate of complete rotations of cylinder 24 (i .e.,
  • the present invention overcomes this limitation by providing means for rotating one of the cylinders 24 or 26 at a constant RPM but with an angular velocity which varies between minimum and maximum values during each complete cycle.
  • RPM is given by
  • the noncircular gearing system employed herein is generally designated 48 and comprises apair of elliptical gears 50 and 52, gear 5% being the driving gear and gear 52 being the driven gear.
  • gear 5% being the driving gear
  • gear 52 being the driven gear.
  • the conditions for operative meshing engagement are satisfied when, as shown in FIG. 2, the two elliptical gears are identical and are mounted at one of their foci on shafts, respectively,
  • FIG. 5 shows an ellipse having two foci F1 and F2, a major axis 2a and a minor axis 2b, and is defined by the property that the sum of the distances r1 and r2 from any point on the circumference to the foci F1 and F2 is equal to the major axis 2a.
  • the minimum and maximum distances from a focus to the circumference extend along the major axis and are designated and d respectively.
  • the effective radius of the sealing cylinder (the distance from its center to the outer surface of the sealing bar 32) is equal to the radius of the smooth cylinder 24 or
  • FIG. 4 shows an intermediate position of sealing bar 32, sealing engagement occurring at a velocity between the minimum and maximumvalues.
  • the bag length L may be adjusted to any value merely by adjusting the ratio w1/w3.
  • the ratio w1/w3 is limited by the condition that W] must equal w2 at the point of sealing engagement.
  • bag length may be varied as follows:
  • shafts 28 and 54 within the range defined by equation may be accomplished in a variety of ways.
  • these shafts might have a common drive motor accompanied by adjustable transmission mechanisms capable of establishing .a plurality of selected speed ratios for selecton of a plurality of predetermined bag lengths.
  • Such an arrangement is illustrated schematically in FIG. 6.
  • shaft 28 is driven by a variable speed motor M1 and shaft 54 is driven by a second variable speed motor M2.
  • Speed adjustment of motors M1 and M2 may be accomplished in a well known manner by potentiometers illustrated schematically and designated P1 and P2, respectively.
  • the speed ratio of motors M1 and M2 might be conveniently adjusted through a common control knob by.
  • the two differential amplifiers arecontrolled simultaneously by cams Cl and C2 mounted on a control shaft 64.
  • Cams C1 and C2 are designed in accordance with the relationships established by equations (14) and (25) respectively, establishing bag length L as a function of speed ratio wl/w3 and angular position of cylinder 26, respectively.
  • a control knob 66 is provided on one end of shaft 64 together with a pointer 68 and indicator dial 70.
  • the indicator dial may be calibrated directly in terms of bag length. As a result, the operator merely rotates knob 66 to the desired bag length and the speed ratio w1/w3 and angle 4) are automatically adjusted to the proper values.
  • the cutting cylinder 44 is drivingly linked to the sealing cylinder 26 by means of a belt 72 trained around a pair of pulleys 74 and 76.
  • Pulley 74 is mounted fast on shaft 30 and pulley 76 is mounted fast on shaft 46.
  • the effective radii of the pulleys are established such that the RPM of cutting cylinder 44 is identical to that of sealing cylinder 26 and the cutting position of cylinder 44 is adjusted to correspond with the sealing position of sealing cylinder 26 to provide the desired (usually small) spacing between a sealing joint and a perforation.
  • the present invention as described herein not only provides increased flexibility and efficiency in auto-" mated bag making apparatus but also may provide an" increase in output rate with no loss of quality.
  • the elliptical gears and the smooth cylinder may be designed such that the sealing operation occurs at the minimum. angular speed. If the drive mechanisms are now re-v versed, with the sealing cylinder being driven at a constant angular velocity and the smooth feed cylinder being driven by the elliptical gears, it will be apparent ⁇ that the average linear speed of the web (i.e., the output) is greater than the instantaneous speed at which sealing occurs. Stated in other terms, output is. increased by increasing the feed velocity of the web between sealing operations while maintaining the characteristic of low speed at the instant of seal, thus maximiz-g ing seal quality. However, it should be noted that the stretch and tear qualities of the web must be considered in the design of such a system.
  • thermoplastic bags The apparatus is characterized by a length adjustment system which is relatively simple and inexpensive in construction and operation and provides enormous flexibility in making bags of any desired length within a wide range. Length adjustment in accordance with my design requires no change of parts and indeed may be accomplished dur- 'ing operation thereby eliminating costly shutdown time.
  • the apparatus provides increased accuracy and may be used to significantly increase output while maintaining low speed seal quality.
  • a rotary web material working apparatus adapted to operate on web material at spaced intervals therealong comprising an operating station, feed means adapted to feed said web material past said operating station, variable speed web drive means adapted to drive said web feed means at an adjustable speed thereby to adjust the velocity of said web material, operating means comprising an operating member, a variable speed operating member drive means operatively drivingly connected to said operating member for moving same in a cyclical manner at an adjustable frequency, said operating member engaging said web while moving in' the direction of web feed once during each operating cycle, adjustable control means operatively connected to said web drive means and to said operating member drive means for simultaneously controlling web speed and operating member frequency and effective to vary the ratio therebetween, and means to vary the instantaneous velocity of said operating member at the moment of engagement with said web material at said operating station, manual adjusting means operatively connected to said control means, to said operating member and to said instantaneous velocity varying means and effective to.
  • said drive operating member means comprises a rotary member, means to rotate said rotary member, and means mounting said operating member on said rotary member for movement therewith, said location adjusting means comprising means to adjust the angular position of said operating member relative to said rotary member.
  • said operating member drive means comprises a rotary drive member adapted to rotate at a constant angular speed, said means to vary the instantaneous velocity of said operating member along said cyclical path comprising noncircular gearing means operatively drivingly connected between said drive member and said rotary member and effective to convert said constant angular velocity of said drive member into a periodicallyvarying angular velocity of said rotary member.
  • noncircular gearing means comprises a pair-of elliptical gears.
  • said web feed means comprises a second rotary member, a second rotary drive means operatively connected to said second rotary member and effective to rotatably drivesame
  • said control means comprises means operatively connected to said first and second rotary drive means and effective to simultaneously vary the relative rate of complete rotations of said rotary members.
  • said instantaneous velocity varying means comprises means to periodically vary the instantaneous velocity of said operating member along said cyclical path during each operating cycle, means to adjust the location along said cyclical path at which said operating member engages said web, thereby to adjust the velocity of said operating member at the moment of engagement with said web material.
  • 5- h apparatus of C im ul ss nw .d i QP' crating member means comprises a rotary drive member adaptedto rotate at a constant angular speed, said relative velocity varying means comprising, noncircular gearing means operatively drivingly connected between said drive member and said rotary member and effective to convert said constant angular velocity of said drive member into a periodically varying angular velocity of said rotary member.
  • the apparatus of claim 10 further comprising means operatively connected to said angular position adjusting means and to said control means and effectiveto automatically actuate saidl angular position adjusting means in response to a variation in the rate of complete revolutions of said operating member relative to said web velocity thereby to adjust the position of said operating member such that it engages said web at a velocity equal to the web velocity.
  • said operating member drive means comprises a rotary drive member adapted to rotate at a constant angular speed, said means to vary the instantaneous velocity of said operating member along said cyclical path comprising noncircular gearing means operatively drivingly connected between said drive member and said rotary member and effective to convert said constant angular velocity of said drive member into a periodially varying angular velocity of said rotary member.
  • said manual adjusting means further comprises a rotary control shaft effective to control the speedof said web and said operating member drive means, a manually actuatable control member and first cam means operatively connected between said control shaft and said control member and effective to rotate said control shaft by an amount which is a function of the position of said control member.
  • noncircular gearing means comprises a pair of elliptical gears.

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Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0003998A3 (en) * 1978-03-09 1979-10-17 Stiegler, Karl Heinz Machine for working a web of material by a welding tool
US4283975A (en) * 1978-09-16 1981-08-18 Jagenberg Werke Ag System for setting the sheet length on a crosscutter for webs of material
GB2171050A (en) * 1984-01-31 1986-08-20 Astin France Sarl Method and equipment for cyclically treating a travelling web
WO1986007564A1 (fr) * 1985-06-20 1986-12-31 Elwaplastic Maschinenbau Gmbh Dispositif pour soudage et decoupage transverseaux d'une feuille continue pliee
US4950217A (en) * 1986-11-05 1990-08-21 Fas Converting Machinery Aktiebolag Bag making machine with coupling-controlled perforating and welding
FR2668734A1 (fr) * 1990-11-06 1992-05-07 Pierre Paessens Procede et machine de confection de facon rotative de sachets flexibles thermo-soudables, avec ou sans presence d'auto-adhesifs.
EP0537127A1 (en) * 1991-09-06 1993-04-14 Fas Converting Machinery Aktiebolag Method and arrangement in a bag-making machine for forming weld lines in a web fed therethrough
US5215514A (en) * 1991-09-06 1993-06-01 Fas Converting Machinery Ab Method and arrangement in a bag-making machine for forming weld lines in a web fed therethrough
US5292299A (en) * 1992-11-25 1994-03-08 Fmc Corporation Maintaining perforation phasing
US5417638A (en) * 1992-11-25 1995-05-23 Fmc Corporation Method and apparatus for maintaining proper perforation phasing
US5967961A (en) * 1997-05-02 1999-10-19 Fas Converting Machinery Ab Welding unit and bag-making machine with such a welding unit
US6040667A (en) * 1995-12-12 2000-03-21 Valeo Elecrical Systems, Inc. System and method for driving wipers in a windshield wiper system
US6139479A (en) * 1998-02-23 2000-10-31 Reynolds Consumer Products, Inc. Apparatus and method for manufacture of containers of variable length
US6475128B1 (en) * 1999-05-26 2002-11-05 J&L Development, Inc. Apparatus and method for individually controlling motors in a carton folding machine in order to automatically execute a carton folding process
US20080234119A1 (en) * 2007-03-23 2008-09-25 Dixie Consumer Products Llc Servo-driven forming press
US20170072625A1 (en) * 2005-12-13 2017-03-16 Delta Industrial Services, Inc. Reciprocating sealer for web converters

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US1897867A (en) * 1931-08-29 1933-02-14 Samuel M Langston Co Cut-off mechanism
US1951536A (en) * 1933-06-08 1934-03-20 George W Swift Jr Inc Variable drive mechanism
US1997608A (en) * 1933-01-03 1935-04-16 George W Swift Jr Inc Variable speed cutting mechanism
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US2146274A (en) * 1935-06-25 1939-02-07 S & S Corrugated Paper Mach Knife
US2560473A (en) * 1948-08-18 1951-07-10 Potdevin Machine Co Mechanism for successively producing bag lengths from continuously advancing tubularwebs
US2822047A (en) * 1955-01-26 1958-02-04 United States Steel Corp Flying shear
US2861635A (en) * 1955-01-27 1958-11-25 United States Steel Corp Power transmitting apparatus
US3003380A (en) * 1959-01-26 1961-10-10 Samuel M Langston Co Flying cutter control means for varying flying frequency and retaining flying speed of cutters

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Publication number Priority date Publication date Assignee Title
US1897867A (en) * 1931-08-29 1933-02-14 Samuel M Langston Co Cut-off mechanism
US1997608A (en) * 1933-01-03 1935-04-16 George W Swift Jr Inc Variable speed cutting mechanism
US2054406A (en) * 1933-02-20 1936-09-15 Dobeckmun Co Universal bag machine
US1951536A (en) * 1933-06-08 1934-03-20 George W Swift Jr Inc Variable drive mechanism
US2146274A (en) * 1935-06-25 1939-02-07 S & S Corrugated Paper Mach Knife
US2560473A (en) * 1948-08-18 1951-07-10 Potdevin Machine Co Mechanism for successively producing bag lengths from continuously advancing tubularwebs
US2822047A (en) * 1955-01-26 1958-02-04 United States Steel Corp Flying shear
US2861635A (en) * 1955-01-27 1958-11-25 United States Steel Corp Power transmitting apparatus
US3003380A (en) * 1959-01-26 1961-10-10 Samuel M Langston Co Flying cutter control means for varying flying frequency and retaining flying speed of cutters

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0003998A3 (en) * 1978-03-09 1979-10-17 Stiegler, Karl Heinz Machine for working a web of material by a welding tool
US4268343A (en) * 1978-03-09 1981-05-19 Karl Heinz Stiegler Machine for working on a web of material by means of a welding tool
US4283975A (en) * 1978-09-16 1981-08-18 Jagenberg Werke Ag System for setting the sheet length on a crosscutter for webs of material
GB2171050A (en) * 1984-01-31 1986-08-20 Astin France Sarl Method and equipment for cyclically treating a travelling web
WO1986007564A1 (fr) * 1985-06-20 1986-12-31 Elwaplastic Maschinenbau Gmbh Dispositif pour soudage et decoupage transverseaux d'une feuille continue pliee
US4950217A (en) * 1986-11-05 1990-08-21 Fas Converting Machinery Aktiebolag Bag making machine with coupling-controlled perforating and welding
FR2668734A1 (fr) * 1990-11-06 1992-05-07 Pierre Paessens Procede et machine de confection de facon rotative de sachets flexibles thermo-soudables, avec ou sans presence d'auto-adhesifs.
EP0537127A1 (en) * 1991-09-06 1993-04-14 Fas Converting Machinery Aktiebolag Method and arrangement in a bag-making machine for forming weld lines in a web fed therethrough
US5215514A (en) * 1991-09-06 1993-06-01 Fas Converting Machinery Ab Method and arrangement in a bag-making machine for forming weld lines in a web fed therethrough
US5417638A (en) * 1992-11-25 1995-05-23 Fmc Corporation Method and apparatus for maintaining proper perforation phasing
US5292299A (en) * 1992-11-25 1994-03-08 Fmc Corporation Maintaining perforation phasing
US6040667A (en) * 1995-12-12 2000-03-21 Valeo Elecrical Systems, Inc. System and method for driving wipers in a windshield wiper system
US5967961A (en) * 1997-05-02 1999-10-19 Fas Converting Machinery Ab Welding unit and bag-making machine with such a welding unit
US6139479A (en) * 1998-02-23 2000-10-31 Reynolds Consumer Products, Inc. Apparatus and method for manufacture of containers of variable length
US6475128B1 (en) * 1999-05-26 2002-11-05 J&L Development, Inc. Apparatus and method for individually controlling motors in a carton folding machine in order to automatically execute a carton folding process
US20170072625A1 (en) * 2005-12-13 2017-03-16 Delta Industrial Services, Inc. Reciprocating sealer for web converters
US10654224B2 (en) * 2005-12-13 2020-05-19 Delta Industrial Services, Inc. Reciprocating sealer for web converters
US12251888B2 (en) 2005-12-13 2025-03-18 Delta Industrial Services, Inc. Reciprocating sealer for web converters
US20080234119A1 (en) * 2007-03-23 2008-09-25 Dixie Consumer Products Llc Servo-driven forming press
US10828858B2 (en) * 2007-03-23 2020-11-10 Gpcp Ip Holdings Llc Servo-driven forming press

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