Classifications

• • 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
  • B29C66/83413—Roller, cylinder or drum types cooperating rollers, cylinders or drums
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
  • B23K20/10—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating making use of vibrations, e.g. ultrasonic welding
• • 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
  • B29C65/08—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using ultrasonic vibrations
  • B29C65/083—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using ultrasonic vibrations using a rotary sonotrode or a rotary anvil
  • B29C65/087—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using ultrasonic vibrations using a rotary sonotrode or a rotary anvil using both a rotary sonotrode and a rotary anvil
• • 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
  • B29C66/006—Preventing damaging, e.g. 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
  • B29C66/01—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
• • 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
  • B29C66/735—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 extensive physical properties of the parts to be joined
  • B29C66/7352—Thickness, e.g. very thin
• • 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
  • B29C66/8223—Worm or spindle mechanisms
• • 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
  • B29C66/8226—Cam mechanisms; Wedges; Eccentric mechanisms
• • 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
  • B29C66/8242—Pneumatic or hydraulic drives
  • B29C66/82421—Pneumatic or hydraulic drives using an inflatable element positioned between the joining tool and a backing-up part
• • 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
  • B29C66/90—Measuring or controlling the joining process
  • B29C66/92—Measuring or controlling the joining process by measuring or controlling the pressure, the force, the mechanical power or the displacement of the joining tools
  • B29C66/924—Measuring or controlling the joining process by measuring or controlling the pressure, the force, the mechanical power or the displacement of the joining tools by controlling or regulating the pressure, the force, the mechanical power or the displacement of the joining tools
  • B29C66/9261—Measuring or controlling the joining process by measuring or controlling the pressure, the force, the mechanical power or the displacement of the joining tools by controlling or regulating the pressure, the force, the mechanical power or the displacement of the joining tools by controlling or regulating the displacement of the joining tools
  • B29C66/92611—Measuring or controlling the joining process by measuring or controlling the pressure, the force, the mechanical power or the displacement of the joining tools by controlling or regulating the pressure, the force, the mechanical power or the displacement of the joining tools by controlling or regulating the displacement of the joining tools by controlling or regulating the gap between the joining 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
  • B29C66/80—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
  • B29C66/8222—Pinion or rack mechanisms
• • 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
  • B29C66/8242—Pneumatic or hydraulic drives
• • 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
  • B29C66/92—Measuring or controlling the joining process by measuring or controlling the pressure, the force, the mechanical power or the displacement of the joining tools
  • B29C66/929—Measuring or controlling the joining process by measuring or controlling the pressure, the force, the mechanical power or the displacement of the joining tools characterized by specific pressure, force, mechanical power or displacement values or ranges
• • 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
  • B29C66/95—Measuring or controlling the joining process by measuring or controlling specific variables not covered by groups B29C66/91 - B29C66/94
  • B29C66/951—Measuring or controlling the joining process by measuring or controlling specific variables not covered by groups B29C66/91 - B29C66/94 by measuring or controlling the vibration frequency and/or the vibration amplitude of vibrating joining tools, e.g. of ultrasonic welding tools
  • B29C66/9513—Measuring or controlling the joining process by measuring or controlling specific variables not covered by groups B29C66/91 - B29C66/94 by measuring or controlling the vibration frequency and/or the vibration amplitude of vibrating joining tools, e.g. of ultrasonic welding tools characterised by specific vibration frequency values or ranges

Definitions

• the present invention relates to ultrasonic horns. More particularly, the present invention relates to mounting an ultrasonic horn.
• ultrasonic welding In ultrasonic welding (sometimes referred to as “acoustic welding"), two parts to be j oined (typically thermoplastic parts) are placed directly below a tool called an ultrasonic
• An ultrasonic type vibratory welding system basically comprises an electrical generating means, an electrical ultrasonic converter for converting electrical energy into vibratory energy, the horn for delivering the vibratory energy into the weld zone, and an assembly for applying a static force to the workpieces so as to hold the workpiece in forced contact with the tool.
• the energy is imparted from the tool to the workpiece at a selected wavelength, frequency, and amplitude.
• the ultrasonic horn is an acoustical tool made of, for example, aluminum or titanium that transfers the mechanical vibratory energy to the part.
• ultrasonic welding is continuous ultrasonic welding. This type of ultrasonic welding is typically used for sealing fabrics and films, or other workpieces which can be formed into a "web" and fed through the welding apparatus.
• the ultrasonic horn is typically stationary and the part is moved beneath it.
• One type of continuous ultrasonic welding uses a rotationally fixed bar horn and a rotationally fixed anvil surface. The workpiece is pulled between the bar horn and the anvil. The horn typically extends longitudinally towards the workpiece and the vibrations travel axially along the horn into the workpiece.
• the horn is a rotary type which is cylindrical and rotates about a longitudinal axis.
• the input vibration is in the axial direction of the horn and the output vibration is in the radial direction of the horn.
• the horn is placed close to an anvil which typically is also able to rotate so that the workpiece to be welded (or bonded) passes between the cylindrical surfaces at a linear velocity which substantially equals the tangential velocity of the cylindrical surfaces.
• This type of ultrasonic welding system is described in U.S. Pat. No. 5,976,316, incorporated by reference in its entirety herein.
• the juxtaposition of the anvil to the horn allowed a static force to be provided to the workpiece, allowing the transmission of the ultrasonic energy to the workpiece.
• This static force was typically maintained by providing a pinching force to the workpiece from a force application system (e.g., using a fluid hydraulic system) which forced the horn radially towards the longitudinal axis of the anvil.
• a force application system e.g., using a fluid hydraulic system
• the problem with this method of securing the workpiece was that when the workpiece being welded became extremely thin, or contained holes, the horn and the anvil could physically contact each other. When the horn contacted the anvil, a large spike in energy consumption occurred through the system, similar to an electrical short circuit. As throughput speeds of the workpiece were increased, the level of energy introduced through the horn was also increased, causing the frequency of the surges of energy which occurred during contact of the horn and anvil to exponentially increase.
• ultrasonic welding systems were developed which maintained a gap between the anvil and the horn. This gap was typically narrower than the thickness of the workpiece.
• the support structure was necessarily rigid, to maintain the angular position of both the horn and the anvil with respect to each other. Mis-aligning the surfaces of the horn and anvil caused poor welding and loss of product.
• attempting to adjust the distance of the gap in this type of system allowed an unacceptable level of movement to be introduced into the system, once again causing mis- adjustment of the surfaces of the horn and anvil.
• the invention includes an apparatus comprising an ultrasonic horn.
• the horn is mounted to a support structure and includes a first mounting surface.
• An anvil is mounted to the support structure and spaced from the ultrasonic horn.
• the anvil has a first bearer surface.
• a bearer assembly supportably links the first mounting surface to the first bearer surface.
• Another aspect of the invention includes a method for mounting an ultrasonic welding horn comprising securing the ultrasonic horn to a support structure.
• the horn has a welding surface and a first mounting surface.
• An anvil having a pressing surface and a first bearing surface is disposed such that the pressing surface is proximate to the welding surface.
• the welding surface and the pressing surface are biased towards each other.
• a linkage structure links the first bearing surface to the first mounting surface so as to prevent the pressing surface and the welding surface from coming into contact.
• FIG. 1 is an elevational view of an ultrasonic welding system.
• FIG. 1 A is a cross-sectional view of a guide portion of an ultrasonic welding system, as taken along line 1A-1A of FIG. 1.
• FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1.
• FIG. 3A is a detailed view of the area indicated by reference number 3 in FIG. 2.
• FIG. 3B is the same view as FIG. 3A, but with a larger gap between the welding surface of the horn and the pressing surface of the anvil.
• FIG. 4A is an elevational view of a portion of the bearer assembly taken from the anvil end of the eccentric shaft.
• FIG. 4B is an elevational view of a portion of the bearer assembly taken from the anvil end of the eccentric shaft.
• FIG. 5 is a cross-sectional view of the bearer assembly. While the above- identified drawings set forth one preferred embodiment, other embodiments of the present invention are also contemplated, as noted in the discussion. This disclosure presents an illustrative embodiment of the present invention by the way of representation and not limitation. Numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention.
• Ultrasonic welding device 10 includes at least one horn assembly 12, horn assembly guide 14, anvil roll 16 having longitudinal axis 17 (shown running into the page in FIG. 1) and mounting plate 18.
• Horn assembly guide 14 and anvil roll (or anvil, or roll) 16 are mounted to mounting plate 18 so as to dispose ultrasonic horn 20 included in horn assembly 12 proximate to anvil roll 16.
• web 22 (shown in dotted lines before being welded and solid lines after welding) is threaded through welding device 10 so as to ride on axially extending pressing surface 19 of anvil roll 16 between pressing surface 19 and ultrasonic horn 20. While one horn assembly 12 is illustrated, any number may be utilized without departing from the spirit and scope of the invention.
• Faceplates 24 are provided for structural support of horn assembly 12, and may include stiffening braces 26.
• Pressure system 30 (shown in dotted lines in FIG.l) is included with horn assembly 12 to drive the ultrasonic horn 20 radially inward towards the anvil roll 16.
• a pressure system could be used to drive the anvil towards the longitudinal axis of the horn, or simultaneously drive the horn and anvil towards each other.
• This pressure system can utilize any number of methods to generate force, including utilizing pneumatic, mechanical (e.g., gear driven, screw jack), or electronic apparatus, as would be known to one skilled in the art.
• Ultrasonic hom 12 is allowed to translate radially inward along tracks (or grooves) 31b in horn assembly guide 14, as shown in Fig. 1A.
• tracks (or grooves) 31b in horn assembly guide 14 as shown in Fig. 1A.
• cam followers 31 a are secured to each hom assembly 12 and are inserted into grooves 3 lb in hom assembly guide 14. The relation of cam followers 31 a in grooves 31b allows hom assembly 12 (including hom 20) to translate radially toward and away (arrow 29a) from anvil 16.
• Cam followers 31a and grooves 31b prevent hom assembly 12 from moving transversely (into and out of the page when viewing FIG. 1 A and in the direction of arrow 29b in FIG. 1). Translation of hom assembly 12 in an axial direction shown by arrow 29c is limited by a series of individual bearings 31c, which abut stop surfaces 3 Id on hom assembly guide 14. Rotation of hom assembly 12 about the axis defined by arrow 29c is also prevented by cam followers 31a. A slight amount of clearance is provided between inner wall 31 e of grooves 31 b and cam followers 31a, allowing each hom assembly 12 to rotate along the longitudinal direction (arrows 29e and 29f) about axis 29b (see FIG. 1). Stop surfaces 3 Id limit this longitudinal rotation of hom assembly 12.
• Bearer rings 32 are included as part of anvil roll 16, and are mounted on radially extending faces 34 of anvil roll 16 (e.g., by bolting, welding, etc.). Bearer rings 32 are concentric with anvil roll 16, as best shown in FIG. 2.
• FIG. 2 illustrates a cross-section taken through hom assembly 12 and is representative of any hom assembly mounted according to the present invention.
• Bearing rings 32 extend axially from radially extending faces 34 of anvil roll 16, forming axially extending bearer surfaces 36.
• Anvil roll 16 is machined such that pressing surface 19 of anvil roll 16 and bearer surface 36 of bearer rings 32 each are substantially concentric to longitudinal axis 17 of anvil roll 16. Additionally, the radial distance (indicated by reference number 37 in FIG. 2) between the pressing surface 19 and the bearer surface 36 is maintained at a substantially constant distance, preferably at approximately 3.169 inches (80.493 mm), regardless of the rotational position of anvil 16.
• bearer surface 36 radially spaced from pressing surface 19, it should be understood that bearer surface 36 could be placed anywhere on anvil roll 16 (or on any part of the assembly making up the anvil roll, such as bearer rings 32) with respect to pressing surface 19.
• hom 20 includes welding portion 20a and mounting (or shaft) portions 20b.
• Outer surface 38 of hom 20 can similarly be divided into welding surface 38a and mounting (or bearer) surfaces 38b. While the illustrated embodiment shows mounting surfaces 38b disposed longitudinally on both sides of the welding surface 38a, it should be understood that mounting surfaces may be disposed anywhere on hom 20. Additionally, any number of mounting surfaces may be used.
• ultrasonic welding device 10 As web 22 is fed through ultrasonic welding device 10, it passes between welding surface 38a of hom 20 and pressing surface 19 of anvil roll 16 (which typically has various surface protrusions, as is known to one skilled in the art) transferring the ultrasonic energy from hom 20 to web 22 as it is pinched between hom 20 and anvil 16, thereby welding web 22.
• Pressure system 30 maintains a constant force on hom assembly 12, providing a compressive (pinching) force on web 22 by pushing hom frame 42 (and thus hom 20) radially inward towards anvil roll 16.
• Horn frame 42 is part of hom assembly 12 and is secured to mounting plate 18 to provide structural support to the hom assembly 12.
• pressure system 30 utilizes an air filled bladder 30A to direct hom 20 radially inward towards anvil 16.
• One side of bladder 30A is mounted to hom frame 42, and the other side of bladder 30a is mounted to support 39.
• Support 39 extends transversely (out of the page when viewing FIG. 2) across welding apparatus 10 and then in the axial direction (as defined by longitudinal axis 17) where it is secured to mounting plate 18.
• air or other fluid
• Isolating devices 40 are attached to shaft portions 20B of ultrasonic hom 20. Isolating devices 40 are used to isolate the vibrational energy of hom 20 from the remainder of hom assembly, including hom frame 42 and faceplate 24.
• One type of isolation device is a set- screw type nodal mount as illustrated in FIGs. 2, 3 A and 3B. Set-screw nodal mounts are adjustable and allow for a wide variety of materials to be used in web 22. Other types of isolation devices, however, may be preferable in certain applications and may be used in the inventive system without departing from the spirit and scope of the invention. Examples of other types of isolating devices include but are not limited to nodal mounts such as those disclosed in U.S. Pat. Nos.
• Patent DE 2,928,360 as well as non-nodal mounts, such as those disclosed in U.S. Pat. Nos. 5,976,316 (Mlinaret al.), 4,884,334 (Houser et al.), 3,955,740 (Shoh), and Japanese Patent JP 4-267130.
• Gear motor 44 is mounted to hom frame 42 and is used to rotate hom 20 about hom longitudinal axis 46. Typically, gear motor 44 is interconnected to hom 20 through timing pulley 48. Horn bearings 49 are disposed circumferentially about isolating devices 40, allowing hom 20 and isolating devices 40 to rotate with respect to the remainder of hom assembly 12.
• Anvil 16 is secured to mounting plate 18 by shaft 50 which extends through anvil 16 along longitudinal axis 17.
• Shaft 50 transfers torque to anvil 16 from a rotational source (not shown).
• the rotational speed of shaft 50 and gear motor 44 are synchronized so as to provide substantially the same tangential velocity at welding surface 38a of hom 20 and axially extending pressing surface 19 of anvil 16, so that drag on the workpiece material (i.e., web 22) is minimized.
• Shaft 50 is rotationally fixed with respect to anvil 16, and shaft bearing 52 is mounted between shaft 50 and mounting plate 18 to allow shaft 50 to be supported by mounting plate 18 while still allowing rotation of shaft 50 with respect to mounting plate 18.
• bearer assemblies (or linkage structures) 60 provide a linkage between mounting surfaces 38b of hom 20 and bearer surfaces 36 on bearer rings 32.
• Bearer assembly 60 acts to isolate the energy resident in shaft portions 20b and mounting surfaces 38b of hom 20 from bearer surfaces 36 and bearer rings 32 of anvil roll 16. Additionally, bearer assembly 60 acts to supportably link mounting surface 38a of hom 20 and bearer surface 36 of anvil roll 16.
• a pre-determined separation distance (or gap) 62 can be maintained between welding surface 38a of hom 20 and pressing surface 19 of anvil roll 16.
• gap 62 is set between approximately 0.0025 inch (0.0635 mm) to approximately 1 inch (25.4 mm), depending upon the application. Note that in FIG. 3A, the web has been omitted so as to clearly illustrate gap 62. Additionally, it should be noted that bearer assembly 60 described with respect to FIG. 3 A is representative of the other bearer assemblies previously illustrated. As discussed previously, bearer assembly 60 includes isolating device 40 (having set-screw 41a) and hom bearings 49. To provide increased strength and stability in bearer assembly 60, first support ring 64 is disposed annularly about and press fit to outer face 41b of isolating device 40. Horn bearings 49 extend annularly about and are press fit onto first support ring 64.
• Bearing spacer 65 extends annularly about first support ring 64 and is disposed axially between hom bearings 49.
• Second support ring 66 extends annularly about horn bearings 49 and bearing spacer 65 and is press fit onto hom bearings 49.
• First and second support rings 64 and 66 in conjunction with bearing spacer 65 facilitate installation of hom bearings 49 into faceplate 24.
• Eccentric shaft 70 extends transversely through aperture 71 in faceplate 24, in a direction parallel to the longitudinal axis of anvil 16 and hom 20. Eccentric shaft 70 includes non-anvil end 72 and anvil end 74. Eccentric shaft 70 is supported by first and second thrust bearings 78a and 78b disposed annularly about eccentric shaft 70 at first and second shaft diameters 80a and 80b. First and second thrust bearings 80a and 80b are seated within faceplate 24 and include annular rims 82a and 82b. Annular shoulders 83a and 83b are disposed internally in aperture 71 and abut about annular rims 82a and 82b, respectively.
• Threaded shaft collar 76 is preferably threaded on to non-anvil end 72 of eccentric shaft 70 to secure thrust bearings 78a and 78b in aperture 71.
• annular shoulders 83a and 83b in combination with thrust bearings 78a and 78b prevent the transverse movement of eccentric shaft 70 within aperture 71 while allowing rotation of eccentric shaft 70 within aperture 71.
• Cam follower bearing 84 is press fit annularly about anvil end 74 of eccentric shaft 70.
• Follower surface 86 of cam follower bearing 84 engages bearer surface 36 of bearer ring 32.
• hom 20 (as part of hom assembly 12) is driven radially towards anvil 16 (FIGs. 3 A and 3B), in the direction of arrow 94 by pressure system 30 (described previously with respect to FIGs. 1 and 2).
• pressure system 30 described previously with respect to FIGs. 1 and 2.
• faceplate 24, isolation device 40, first and second support rings 64 and 66, bearing spacer 65, hom bearings 49 thrust bearings 78a and 78b, eccentric shaft 70 and cam follower bearing 84 translate inward as well.
• Rotation of hom 20 is isolated from faceplate 24 by hom bearings 49.
• Ultrasonic vibrations are isolated from faceplate 24 by isolating device 40.
• eccentric shaft 70 extends through faceplate 24 at aperture 71, downward force is translated through thmst bearings 78a and 78b, to eccentric shaft 70 and finally to cam follower bearing 84.
• follower surface 86 of cam follower bearing 84 is translated inward until it engages bearer surface 36 of bearer ring 32, preventing further inward movement of cam follower bearing 84.
• Cam follower bearing 84 allows anvil 16 to rotate with respect to bearer assembly 60.
• the radial separation distance of the bearer assembly 60 (i.e., the distance between mounting surface 38b of hom 20 and bearer surface 36 of anvil 16) is set so that mounting surface 38b of hom 20 engages bearer surface 36 of anvil 16 before welding surface 38a of hom 20 engages pressing surface 19 of anvil. This allows radial forces to translate directly from hom assembly 12 to anvil 16 while still maintaining gap 62 (preventing contact) between welding surface 38a of hom 20 and pressing surface 19 of anvil.
• the inventive mounting system eliminates overload downtime as well as maintaining quality product output at higher web throughput than was attainable by previous ultrasonic welding devices.
• the support structure i.e., mounting plate 18, shown previously
• the support structure for the hom and the anvil does not need to be built to provide a large amount of stiffness (assuring angular position) and can be reduced in size and in cost from that required in previous gap type ultrasonic welding systems.
• Worm 88 and worm gear 90 allow eccentric shaft 70 to be rotated by an operator, forcing the bearer assembly 60 radially inward in the direction of arrow 94 or allowing the bearer assembly 60 to travel radially outward in the direction of arrow 92.
• bearer assembly 60 is urged radially outward (direction 92) hom 20 is lifted at mounting surface 38b, causing gap 62 to widen.
• cam follower bearing 84 is allowed to move radially inward (direction 94) pressure system 30 (previously described with respect to FIGs.
• FIG.4 A is a view taken from anvil end 74 of eccentric shaft 70, illustrating the use of eccentric shaft 70 to translate the bearer assembly 60 radially inward or outward (i.e., "lengthen” or “shorten” the bearer assembly 10).
• eccentric shaft 70 has a central axis 100 disposed through the center of anvil end 74 (the eccentric end) of eccentric shaft 70 and a longitudinal axis 104 about which eccentric shaft 70 rotates.
• eccentric shaft 70 The distance between these axises is commonly referred to as the "eccentricity of the shaft.” As illustrated, disposing eccentric shaft rotationally so as to position central axis 100 of anvil end (or eccentric portion) of eccentric shaft 70 radially outward from longitudinal (or rotational) axis 104 of shaft 70 defines a first distance 108 from bearer surface 36 of bearer ring 32 to longitudinal axis 104 of eccentric shaft 70. Eccentric shaft 70 can be rotated by the operator about longitudinal axis 104 until central axis 100 of eccentric shaft 70 is disposed generally radially inward from longitudinal axis 104 of shaft 70, as shown in FIG. 4B.
• Rotating eccentric shaft 70 in this manner defines a second larger distance 110 from bearer surface 36 of bearer ring 32 to longitudinal axis 104. It should become evident that by changing the rotational position of eccentric shaft 70, the distance between longitudinal axis 104 of eccentric shaft 70 and top surface 106 of bearer ring 32 can be varied from between first distance 108 (shown in FIG. 4A) and second distance 110 (shown in FIG. 4B). This distance can be defined as variable distance 112.
• the "length" of the bearer assembly 60 or in other words, the distance defined by bearer assembly 60 between mounting surface 38b of horn 20 and bearer surface
• variable distance 112 is also the distance through which gap 62 can be adjusted and is also equal to twice the eccentricity of shaft 70.
• FIG. 5 illustrates worm 88 and worm gear 90 used in combination with eccentric shaft 70.
• Worm 88 preferably has knob 114 attached so as to allow an operator to easily grasp and rotate worm 88. Teeth on worm 88 engage mating teeth on worm gear 90.
• Worm gear 90 is press fit about or pinned to eccentric shaft 70 so that it is locked rotationally to eccentric shaft 70.
• knob 114 By turning knob 114, ridges of worm 88 drive worm gear 90 and eccentric shaft 70 either clockwise or counterclockwise (as when viewing FIG. 5) depending on the direction knob 114 is rotated.
• the operator can adjust gap 62 without disassembling of the welding device 10. Adjusting the length of bearer assemblies 60 on opposite ends of hom 20 (as illustrated in FIG.
• the operator allows the operator to manually compensate for any variation in dimensions (i.e., due to machining tolerances, etc.) in hom 20 or anvil 16.
• the operator can slightly rotate the hom assembly 12 along its longitudinal axis (as discussed with respect to FIG. 1A) to adjust the angular relation of welding surface 38a of hom 16 with respect to pressing surface 19 of anvil 16.
• bearer assembly 60 While one adjustment embodiment has been discussed with respect to bearer assembly 60, it would be understood by a person skilled in the art that other adjustment methods could be used without departing from the spirit and scope of the claims (e.g., taper (wedge) blocks, replaceable shims, lever arms, differential screws, thermal expansion, etc.).
• the bearer assembly 60 can be reconfigured such that the apparatus utilized to adjust the length of the bearer assembly 60 contacts a surface on the hom, or in the middle of the bearer assembly versus directly contacting a surface on the anvil.

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• Engineering & Computer Science (AREA)
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• Fluid Mechanics (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)
• Pressure Welding/Diffusion-Bonding (AREA)

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