ULTRASONIC SEALER

Abstract: An ultrasonic sealing apparatus capable of being provided on a sealing jaw of a transverse sealing apparatus for a filling/packing machine, carrying out a suitably long transverse sealing operation or an elongated uniform heat sealing operation, being formed to small dimensions, and capable of outputting a large power. The ultrasonic sealing apparatus comprises one horn 11 having an elongated sealing surface 15 for sealing a packing material, plural converters 12 erected on the horn 11, and one or more not less than two fixtures 13 provided in parallel with the converters 12, positions in which the ultrasonic sealing apparatus 10 and sealing jaw are fixed to each other in the fixtures 13 being set on a nodal plane 26 farther from the sealing surface, and the horn 11 being provided with an attaching flange for fixing the ultrasonic sealing apparatus to the sealing jaw, which attaching flange may be set on a nodal plane closer to the sealing surface.

Description: Technical Field The present invention relates to an ultrasonic sealing apparatus provided with an elongated sealing face for sealing a packing material, specifically a tubular packing material filled with content such as liquid beverages, that is, to an ultrasonic sealing apparatus having at least one horn and plural converters or to a transverse sealing apparatus provided with said ultrasonic sealing apparatus. Background Art Hitherto, there has been known a packing machine in which a sterilized packing material web is used for a rectangular parallelepiped packing container filled with juice, etc. as shown in Fig. 1 (Japanese Patent Publication No.23368/1989). In brief, the filling/packing machine as a whole comprises a reel 2 supporting a packing material web 1 in a rolled state a sterilization device 3 for sterilizing the tubular packing material web successively unwound from the reel 2, a longitudinal sealing section 4 for longitudinally sealing both end portions of the sterilized packing material web and thereby forming a tubular packing material web, a liquid supply tube 5 for filling a fluid content into the web formed into the tubular form, a transverse sealing device 7 for sealing the tubular packing material web in a direction perpendicular to the longitudinal direction thereof while feeding downward the tube filled with the content by a length substantially corresponding to one container and, at the same time, continuously forming pillow-shaped containers 6 which are rectangular in section, and a container shaping device 8 for forming the pillow-shaped containers 6 into rectangular parallelepiped containers which are the final form by folding its end portions. The above-mentioned transverse sealing device 7 is composed of a sealing unit, a sealing jaw for fixing the said sealing unit, and a driving means for driving the said sealing jaw. The following ultrasonic sealing apparatuses are known. Japanese Laid-Open Patent Application No. 2231/1995 discloses an ultrasonic sealing apparatus which comprises a piezoelectric driving unit having a piezoelectric ceramic plate or a magnetostriction driving unit, which is connected to an AC supply source, and a horn having an elongated sealing surface, and which is further characterized with one or more reaction bodies forming a half wavelength together with the horn. Japanese Patent Publication No. 22784/1987 discloses an ultrasonic welding apparatus for a container body comprising a longitudinal groove on the center line of a butting face which has a substantially rectangular form in a side sealing portion of an ultrasonic welding horn, wherein the horn includes steps with small differences provided toward the center of both side faces of the longitudinal groove for side sealing by ultrasound a container body of card board laminated with plastic film. Japanese Patent Publication No. 2544450 discloses a hermetic sealing method for sealing a paper container for liquid characterized in that the method for sealing the open end portions of a container having a thermoplastic layer on its paper surface comprises sealing the upper and lower portions of the tubular body by affixing each end portion of one sheet, whereby an entire face of the open end to be sealed is simultaneously heated in an oven and subsequently preparatively sealed by applying pressure, and finally ultrasonically sealed. Japanese Model Laid-Open Application No. 147408/1988 discloses an ultrasonic sealing apparatus for liquid containers, wherein a band-shaped ridge is provided nearly at the center of a face of the horn butting against a portion to be sealed, a concave groove perpendicular to the said ridge is provided nearly at the center of a face of the anvil butting against the portion to be sealed, a bottom portion of the concave groove is made into a two-step structure and its step portion and both end portions are tapered, and an acute-shaped protruded slant face extending sideward is provided at an end portion of the center of the bottom portion on the ultrasonic sealing apparatus for sealing upper and lower open end portions of a tubular liquid container, which is rectangular in section, having an overlapping bonded portion nearly at a center of a body consisting of a horn and an anvil. Japanese Laid-Open Patent Application No.501543/1987 (PCT/US85/02564) discloses an ultrasonic horn apparatus used for dissolving reagent tablets in a cuvette, comprising a horn body, which is generally a rectangular horn body, having a front end face and a rear end face, for transmitting acoustic waves substantially at a right angle to the front end face to interact with a content in said cuvette which moves in the vicinity of said front end face, in response to vibrations applied to said rear end face, a converter means fixed to said rear end face of said horn body at the center position in the direction of the width of said rear end face for applying said vibrations to said horn body in response to electrical energy supplied to said converter means, and a pair of resonating members each having an acoustic length equal to a half wave length of the acoustic waves transmitted from said horn body and fixed to the end regions in the direction of width of said rear end face and extending at a right angle from said rear end face, for causing acoustic waves transmitted nearly at a right angle from said front end face to propagate at a nearly uniform amplitude along the direction of width of said front end face, wherein the content in said cuvette moving along the direction of width of said front end face at a certain distance from said front end face is subjected to nearly uniform acoustic waves. Japanese Laid-Open Patent Application No. 33121/1995 discloses a sealing apparatus for packing containers comprising an anvil supporting packing materials for the packing containers on whose surface a sealant layer is formed, a horn transmitting ultrasonic vibrations to packing materials by applying pressure pressing said packing materials against the anvil, and an ultrasonic vibration absorbing means provided between the tip end of said horn and the edge portion of said packing material, so that the horn transmits the ultrasonic vibration to the packing materials, and is able to weld sealant layers to each other, while preventing a side of the edge portion of said packing materials from being excited, and accordingly preventing dust from occurring at the end surfaces of the paper substrates exposed at the edge portions of the packing materials. Japanese Laid-Open Patent Application No. 92046/1981 discloses an ultrasonic sealing machine comprising an ultrasonic welding apparatus for a container body comprising a horn including steps at one side edge of a sealing face facing the sealing portion of the horn, wherein the steps are open at the portions corresponding to the vicinity of the top end of the sealing portion for side sealing paper containers of a plastic film laminate and the like. Japanese Laid-Open Patent Application No. 15741/1994 discloses an ultrasonic sealing apparatus for manufacturing packing containers from thermoplastic materials, comprising a giant magnetostrictive powder composite (GMPC) made of magnetostrictive materials, and wherein the vibration generator is wound around by a coil generating a magnetic field and secured on to a sealing jaw, and has a cross sectional area which progressively reduces when seen from an anchorage point against the jaw, and a free face of an end portion is provided on a narrow surface. U.S. Patent No. 5730351 discloses a device for ultrasonic treatment of a workpiece, said device comprising a horn (sonotrode) having a first side and a second side both contacting the workpiece; and a drive unit for said horn, whereby the drive unit includes first and second ultrasound oscillating units, and first and second connecting means arranged spaced apart for individually connecting said first and second oscillation units respectively to said second face of said horn. Japanese Laid-Open Patent Application No. 128237/1998 discloses an ultrasonic apparatus for supplying vibratory energy in the ultrasonic frequency range to a workpiece, the ultrasonic apparatus comprising a horn whose dimension is set to mechanically resonate at a predetermined frequency in the ultrasonic frequency range, plural piezoelectric transducers coupled to said horn for causing said horn to resonate at said predetermined frequency, a power supply connected to said transducers for providing electrical energy at said predetermined frequency to said transducers and causing said transducers to be energized in parallel, and a means for balancing the electrical current flow through said transducers coupled to the circuit between said power supply and each transducer. Furthermore, US-A-3254402 discloses an ultrasonic sealing apparatus which is an ultrasonic sealing apparatus , comprising one horn having an elongated sealing face for sealing a packing material, plural converters erected on a side of the horn opposite to the sealing face for resonating the horn, wherein the length of the ultrasonic sealing apparatus is one wavelength and whose fixing position of the ultrasonic sealing apparatus and the sealing jaw is the nodal plane closer to the sealing face. Disclosure of the Invention At present, a packing material comprising a laminate of paper, aluminum foil and thermoplastic is mainly used for one-use disposable packing containers having a rectangular parallelpiped shape filled with a liquid such as juice and closed in a sealed manner. In the future it is considered that a packing container using a packing material comprising a laminate of thermoplastic having no aluminum foil will be the mainstream, since recycling treatment of packing material laminate including aluminum foil is considered difficult after containers are disposed. However, for heat sealing a packing material comprising a laminate of thermoplastic including no aluminum foil, a heat sealing apparatus using a high-frequency coil which has been used with packing materials including aluminum foil cannot be applied, so it is necessary to use other heat sealing apparatuses such as an ultrasonic sealing apparatus, for example. Generally, an ultrasonic sealing apparatus includes a converter, a booster and a horn. The electrical vibration is converted into mechanical vibration by a converter, and the booster is used to fix the apparatus mechanically and to amplify the amplitude of the vibration. The horn further amplifies the amplitude so that the desired sealing surface is formed. However, the ultrasonic sealing apparatuses, which have well-known properties and which have been generally used, require a larger space for the apparatus when enhancing the heat sealing ability and there is a drawback that such apparatus cannot be set on a sealing jaw of a transverse sealing apparatus of the said filling/packing machine. For practical use, there is a need for an ultrasonic sealing apparatus capable of outputting high power while occupying a much smaller space, and which can be applied to a transverse sealing apparatus. Additionally, uniformly heat sealing the elongated entire face at both end portions has been considered difficult with the known ultrasonic apparatuses used for a sealing jaw of the transverse sealing apparatus of a filling/packing machine, because one converter is used and the dimension of the motional amplitude at the sealing face of the horn (output surface) reduces with increasing lateral distance away from the central area where the converter is coupled to the horn. An aim of an embodiment of the present invention is to provide an ultrasonic sealing apparatus which can be set on a sealing jaw of a transverse sealing apparatus of a filling/packing machine for effecting a transverse sealing of an appropriate length, and in particular an elongated uniform heat sealing, and wherein the ultrasonic sealing apparatus is compact and able to output larger power. According to the present invention there is provided an ultrasonic sealing apparatus which is an ultrasonic sealing apparatus, comprising one horn having an elongated sealing face for sealing a packing material, plural converters erected on a side of the horn opposite to the sealing face for resonating the horn, and one or more fixtures provided parallel to the converter for fixing the ultrasonic sealing apparatus to a sealing jaw, wherein the length of the ultrasonic sealing apparatus is one wavelength and whose fixing position of the ultrasonic sealing apparatus and the sealing jaw in the fixtures is the nodal plane farther from the sealing face. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the fixture has a receiving face of attachment for fixing the ultrasonic sealing apparatus to the sealing jaw and the receiving face of attachment which becomes the fixing position of the ultrasonic sealing apparatus and the sealing jaw is a nodal plane farther from the sealing face. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the fixture has a female screw portion for fixing the ultrasonic sealing apparatus to the sealing jaw using a screw connection. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the fixture has a collar for fixing the ultrasonic sealing apparatus to the sealing jaw, and the collar which becomes the fixing position of the ultrasonic sealing apparatus and the sealing jaw is a nodal plane farther from the sealing face. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the fixture has a screw portion to be fixed to the horn using a screw connection. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the fixture is formed uninterruptedly with the horn. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the horn has a slot and/or slit to reduce unwanted vibrations. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the horn is made of a material having a sonic speed for longitudinal waves at or below 4,000m/s. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the material having a sonic speed for longitudinal waves at or below 4,000m/s is a copper alloy. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the copper alloy is phosphorous bronze. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the converter has a screw portion to be fixed to the horn or to the fixture using screw connection. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the plural converters have a control means in order to obtain a uniform and suitably strong seal at the sealing face. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the screw connection is a screw connection using a stud bolt. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the sealing face has a ridge in the longitudinal direction of the sealing face successively or intermittently. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the frequency ranges from 20KHz to 60KHz. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus wherein the frequency is 40KHz. Further, the present invention relates to the above-mentioned ultrasonic sealing apparatus, which includes a plurality of the above-mentioned ultrasonic sealing apparatuses. Still further, the present invention relates to a transverse sealing apparatus comprising the above-mentioned ultrasonic sealing apparatus and the sealing jaw to which the ultrasonic sealing apparatus is fixed and a driving means for the sealing jaw. Further, the present invention relates to the above-mentioned transverse sealing apparatus wherein the sealing jaw has a damper member for the horn. Any tubular material may be used as the packing material in the present invention, so long as the material can be formed into a container or the like, and the materials have a heat-welding layer such as polyethylene on at least one of front and back sides of a paper or a barrier resin as well as materials having an intermediate layer such as aluminum foil and an adhesive layer on said one side. For example, a packing material web for a filling and packing container of a juice or the like, is composed as a heat-welding layer such as polyethylene provided on the outermost layer surface of front and back faces of a paper which is a base material, and a barrier layer or an adhesive layer and the like of an intermediate layer of aluminum foil or barrier resin is provided as the need arises. Usually a thickness of 170 to 900 µm is adopted for the thickness of the web. Additionally, it is necessary to use materials which can welded by ultrasound for the innermost layer surface contacting the liquid content. The ultrasonic sealing apparatus of the invention is an apparatus capable of heat-sealing by heat dissolving and applying pressure by converting an electrical vibration frequency of 20kHz or higher into a mechanical vibration, delivering an ultrasonic vibration to a heat adhesive part from the resonator which is called a horn, for generating a high frictional heat on the border surface. With a motional amplitude of approximately 15 to 70µm and a vibration frequency of approximately 20,000 to 60,000 times per second, heat is generated in an extremely short time. Thus, an ultrasonic heat-sealing may be regarded as sealing by internal heat as well as sealing using high-frequency. Any horn may be used as the horn of the ultrasonic sealing apparatus in the present invention, so long as it is able to weld sealing layers of the packing material with each other by transmitting ultrasonic vibrations. An exemplary horn includes an elongated sealing face provided on its tip, a curved portion having a curved shape such as a tapered shape, exponential shape or hanging-down shape toward the sealing face, and a flat face portion on a side opposite to the sealing face. On the flat face portion on the side opposite to the sealing face, plural converters and one or more fixtures are erected. Further, it is possible to form the horn and the fixtures uninterruptedly on which uninterrupted body plural converters may be erected. On the other hand, on the sealing face of the horn or the anvil, it is possible to provide a ridge having a round or rectangular shape in its section in the longitudinal direction of the sealing face continuously or intermittently. Additionally it is desirable to use a horn having a slot (a penetrated and elongated hole provided in the direction of thickness) and/or slit (an elongated groove provided in the longitudinal direction) to reduce unwanted vibrations. And generally the slot is provided below the converters and the fixtures, while the slit is provided below between the converters, or below and between the converters and the fixtures. Also in the present invention, it is possible to provide an attaching flange on the horn for fixing the ultrasonic sealing apparatus to the sealing jaw. It is also possible to make the attaching flange as a fixing position of the ultrasonic sealing apparatus and the sealing jaw, and as a nodal plane closer to the sealing face. As a horn material, it is possible to utilize ceramics in addition to metals or alloys such as copper alloys, aluminum or aluminum alloys, titanium or titanium alloys. And when the frequency is fixed, as the length of the horn is in proportion to the sonic speed of the material, from the viewpoint of making an ultrasonic sealing apparatus with smaller dimension, it is desirable to use a horn material having a slow sonic speed of longitudinal waves, for example, of 4,000m/s or lower. Exemplary materials having a sonic speed of longitudinal waves of 4,000m/s or lower include copper alloys such as phosphorous bronze (3,360m/s), beryllium bronze (3,780m/s) and Nepal brass (3,240m/s), or piezoelectric ceramic materials PZT (3,000m/s) may be utilized. In addition, depending on the structure of the transverse sealing apparatus, or in the case that downsizing the apparatus is not required, light metals or light metal alloys and the like whose sonic speed of longitudinal waves is 4,000m/s and above, such as aluminum or aluminum alloys, titanium or titanium alloys and the like, may also be used as the need arises. As mentioned above, the horn is used to apply pressure by pressing a packing material against the anvil with the sealing face provided on the tip of the horn, then to transmit vibratory energy (ultrasonic vibration) concentrated at the tip to heat the adhesive portion of the packing material, thus generating a large frictional heat on the border surface with which the adhesive portion is dissolved by heat. The packing material is thus heat-sealed in cooperation with pressure. While the structure and materials of the anvil are not specially limited, the anvil may by made of, for example, a stainless steel material. Any converter, including electrostrictive and magnetostrictive, may be used for the converters in an ultrasonic sealing apparatus of the present invention, so long as the converter converts the electrical vibration of the vibratory generator to a mechanical vibration and resonates the horn; however, an electrostrictive converter is preferable. In such case, an electrostrictive piezoelectric element using ceramic materials is desirable. Converters of this kind convert the supplied voltage to a mechanical strain, the energy of which strain is supplied to the horn as ultrasonic vibrations. In the ultrasonic sealing apparatus of the present invention, it is necessary to provide plural converters, preferably 2 to 5 converters, in order to obtain an excellent seal. Converters in the present invention are erected on the side of the horn opposite to the sealing face of the horn. This may be achieved by fixing the converters to a flat face portion on the side opposite to the sealing face of the horn or to the flat face portion of the fixture which is fixed to the flat face portion, or by fixing the converters to the flat face portion of the fixture which is formed uninterruptedly with the horn. This fixing may be done by any fixing means so long as it fixes the horn to the converters firmly, while in order to make an ultrasonic sealing apparatus of the present invention with smaller dimension, it is desirable to fix the converters on the horn by a screw connection, specifically by using a stud bolt, for which a female bolt portion is provided on the horn side of the converters. Further, each converter may be connected to a power supply of alternating current and it is desirable to provide a control means in order to transmit the vibratory energy from the plural converters uniformly to the sealing face of the horn in order to obtain a seal with uniform and suitable strength on the sealing face. Without a control means, the vibration becomes non-uniform and there is a possibility that a seal with uniform and suitable strength on the sealing face will not be obtained. The control means may be implemented by a balancing transformer as described in Japanese Laid-Open Patent Application No. 128237/1998. Any fixture may be used in the ultrasonic sealing apparatus in the present invention so long as it fixes the ultrasonic sealing apparatus to the sealing jaw whereby the fixing position, or the vicinity of the fixing position, of the ultrasonic sealing apparatus and the sealing jaw forms a nodal plane farther from the sealing face, and one or more of them are erected on the side opposite to the sealing face of the horn, for example, on the flat face portion of the opposite side. When applied to a transverse sealing apparatus of a filling/packing machine, it is preferable that the ultrasonic sealing apparatus be attached and fixed to the sealing jaw in a compact manner. Accordingly, it is preferable to attach compactly by means of a screw connection using a stud bolt or the like, which is described in the following, rather than fixing the ultrasonic sealing apparatus by providing a flange on the sealing jaw and using the same. On the other hand, for fixing the fixture with the horn, it is preferable to fix compactly by means of a screw connection using a stud bolt and the like. Additionally, it is also possible to form the fixture and the horn together uninterruptedly as aforementioned, or fix a formed body in which a plurality of erected fixtures are coupled in their lower parts to the above-mentioned flat face portion of the horn by screw connection using a stud bolt and the like. The cross-sectional form of the fixture in the present invention may be exemplified as a round or rectangular shape. Fixing the ultrasonic sealing apparatus to the sealing jaw can be achieved, for example, at the end portion of the fixture on the side opposite to the horn or at the center portion of the fixture. When fixed at the end portion of the fixture on the side opposite to the horn, an attachment method such as stud attachment and the like for fixing the ultrasonic sealing apparatus to the sealing jaw is used, for which a female screw portion is used as a fixture. In this case, a female screw portion hole is provided so that a receiving face of the attachment which becomes the fixing position in the fixture is a nodal plane farther from the sealing face. Also, when fixed at the central portion of the fixture, the ultrasonic sealing apparatus is fixed to the sealing jaw by properly coupling a collar provided at the central portion of the fixture with the sealing jaw. In this case, the position of the collar is determined so that the collar-provided portion becomes a nodal plane farther from the sealing face. The position of the nodal plane can be set precisely by a vibration analysis and the like using a computer at the stage of designing fixtures or horns. In the ultrasonic sealing apparatus of the present invention, there exist two nodal planes because the entire length of the apparatus is constituted of one wavelength. The ultrasonic sealing apparatus of the present invention has the nodal plane farther from the sealing face, becoming the fixing position of the ultrasonic sealing apparatus and the sealing jaw. Additionally, it is preferable to provide a damper member at the side frame of the sealing jaw, using the nodal plane closer to the sealing face, for preventing the horn of the ultrasonic sealing apparatus, which is rotating at a high speed, from swinging, and for making the sealing face of the horn butt precisely to the position of a packing material to be sealed. Further, the ultrasonic sealing is preferably performed at a frequency of 20KHz to 60KHz, preferably at 40KHz with the general output at the extent of 2KW, while the entire length of the apparatus including the converters or the fixture and the horn is set to correspond to the length of one wavelength. In such case, the amplitude at the sealing face of the tip end portion of the horn becomes maximum so that the exothermic efficiency is enhanced, thus enlarging the sealing strength. For example, for a horn material with slow sonic speed comprising a material whose sonic speed of the longitudinal wave is 3,600m/s at a frequency of 40KHz, the length of one wavelength is 9cm. In this case, the entire length of the apparatus including the converters, or the fixture and the horn is 9cm to make the length of the converters, the fixture and the horn be 4.5cm respectively. Therefore, when the entire length of the ultrasonic sealing apparatus is to the extent of 10cm, it is possible to be used as a transverse sealing apparatus for the filling/packing machine of the prior art. Moreover, when the traversing face is long as in the case of a large container and a long sealing surface is required, it is possible to enlarge the sealing face by connecting a plurality of the above described ultrasonic sealing apparatuses. Additionally, an ultrasonic sealing apparatus of the present invention may or may not have a booster which is used to amplify the amplitude. Brief Description of the Drawings Fig. 1 is an entire view of the filling/packing machine in which an ultrasonic sealing apparatus of an embodiment of the present invention is applied. Fig. 2 is a schematic perspective view of an ultrasonic sealing apparatus of an embodiment of the present invention. Fig. 3 is a schematic perspective view of an ultrasonic sealing apparatus of another mode of the present invention. Fig. 4 is a schematic front view of an ultrasonic sealing apparatus of another mode of the present invention. Fig. 5 is a schematic front view of an ultrasonic sealing apparatus of another mode of the present invention. Fig. 6 is a schematic front view of an ultrasonic sealing apparatus of an embodiment of the present invention shown in Fig. 2. Fig. 7 is a schematic front view of horns of various shapes in an ultrasonic sealing apparatus of an embodiment of the present invention. Fig. 8 is a schematic side view of horns of various shapes in an ultrasonic sealing apparatus of an embodiment of the present invention. Fig. 9 is a schematic perspective view of an ultrasonic sealing apparatus of a comparative example not forming part of the present invention. Best Modes to Carry Out the Invention The preferable examples of embodiments of an ultrasonic sealing apparatus of the present invention are described according to the drawings in the following, while the present invention is not limited to the description in the drawings. Fig. 2 is a schematic perspective view of an ultrasonic sealing apparatus of an embodiment of the present invention. Fig. 3 is a schematic perspective view of an ultrasonic sealing apparatus of another mode of the present invention. Fig. 4 and Fig. 5 are schematic front views of an ultrasonic sealing apparatus of another mode of the present invention. Fig. 6 is a schematic front view of an ultrasonic sealing apparatus of the embodiment shown in Fig. 2. Fig. 7 is a schematic front view of horns of various shapes in an ultrasonic sealing apparatus of an embodiment of the present invention. Fig. 8 is a schematic side view of horns of various shapes in an ultrasonic sealing apparatus of an embodiment of the present invention. Fig. 9 is a schematic perspective view of an ultrasonic sealing apparatus of a comparative example Additionally, in Fig. 2 to Fig. 9, 10 shows an ultrasonic sealing apparatus; 11 shows a horn; 12 shows a converter; 13 shows a fixture; 14 shows a horn-fixture uninterruptedly formed body; 15 shows a sealing face of the horn; 16 shows a flat face of the horn; 17 shows a curved portion of the horn; 18 shows a slot; 19 shows a slit; 20 shows a collar; 21 shows a stud bolt; 22 shows a receiving face of stud attachment; 23 shows a female screw portion; 24 shows a sealing jaw; 25 shows a damper fixing bolt; 26 shows a nodal plane; 27 shows a stud attachment; 28 shows an attaching flange, respectively. Fig. 2 shows an ultrasonic sealing apparatus 10 of an embodiment of the present invention in which two converters 12 and three fixtures 13 are erected on the horn 11 having the sealing face 15, the flat face 16, the curved portion 17 and the slot 18. In this apparatus 10, the female screw portion 23 for fixing the apparatus to the horn 11 using a stud bolt 21 is provided on the converters 12 and the fixtures 13. Also, the female screw portion 23 for fixing the apparatus with the sealing jaw using a stud attachment 27 is provided on the fixtures 13. Fig. 3 shows an ultrasonic sealing apparatus 10 of an embodiment of the present invention in which two converters 12 are erected on the horn-fixture uninterruptedly formed body 14 by forming the horn 11 and the fixtures 13 together uninterruptedly. In this apparatus 10, likewise the apparatus 10 shown in Fig. 2, the receiving face of stud attachment 22 becomes an attaching position constituting a nodal plane 26 farther from the sealing face 15. Fig. 4 shows an ultrasonic sealing apparatus 10 of an embodiment of the present invention in which two fixtures 13 are erected next to the horn 11 between two converters 12 at both exterior sides, using which two fixtures 13, the ultrasonic sealing apparatus 10 is fixed to the sealing jaw 24 and also in this case, the receiving face of stud attachment 22 is a nodal plane 26 farther from the sealing face 15. Fig. 5 shows an ultrasonic sealing apparatus 10 of an embodiment of the present invention in which one fixture 13 is erected next to the horn 11 between two converters 12 at both exterior sides and in this apparatus 10, the collar 20 provided at the centre portion of the fixtures 13 to fix the apparatus to the sealing jaw 24 becomes an attaching position and a nodal plane 26 farther from the sealing face 15. Fig. 6 shows a state in which the ultrasonic sealing apparatus 10 shown in Fig. 2 is fixed to the sealing jaw 24 and a hexagonal-holed bolt 21 which can be embedded in the sealing jaw 24 is used for fixing the fixtures 13, and as aforementioned, also in this case the receiving face of attachment 22 becomes the fixing position and a nodal plane 26 farther from the sealing face 15. Also, the damper fixing bolt 25 is provided on the side frame of the sealing jaw 24, to prevent the horn from swinging at the curved portion 17 of the horn which becomes a nodal plane closer to the sealing face 15. Fig. 6 also shows the pillow-shaped container 6 which is to be sealed. Additionally, Fig. 7 and Fig. 8 show the horns 17 of various shapes having the sealing face 15, the flat face portion 16 and the curved portion 17, and the slot 18 or the slit 19. Fig. 9 shows the ultrasonic sealing apparatus of a comparative example in which the attaching flange for fixing the ultrasonic sealing apparatus to the sealing jaw is provided on the horn. In this case, the attaching flange becomes the fixing position of the ultrasonic sealing apparatus and a nodal plane closer to the sealing face. Industrial Applicability The present invention makes it possible to provide a smaller ultrasonic sealing apparatus with larger pressure power and enhanced sealing capability compared to the ultrasonic sealing apparatuses of the prior art, and furthermore is capable of uniformly sealing an elongated sealing face.

Claims: An ultrasonic sealing apparatus (10), comprising one horn (11) having an elongated sealing face for sealing a packing material, plural converters (12) erected on a side of the horn (11) opposite to the sealing face (15) for resonating the horn, and one or more fixtures (13) provided parallel to the converters (12) for fixing the ultrasonic sealing apparatus to a sealing jaw (24), wherein the length of the ultrasonic sealing apparatus (10) is one wavelength and whose fixing position of the ultrasonic sealing apparatus and the sealing jaw (24) in the fixtures (13) is the nodal plane (26) farther from the sealing face. An ultrasonic sealing apparatus according to claim 1, wherein the fixture (13) has a receiving face of attachment (22) for fixing the ultrasonic sealing apparatus (10) to the sealing jaw (24), and the receiving face of attachment (22) which becomes the fixing position of the ultrasonic sealing apparatus and the sealing jaw is the nodal plane (26) farther from the sealing face. An ultrasonic sealing apparatus according to claim 1 or 2, wherein the fixture (13) has a female screw position (23) for fixing the ultrasonic sealing apparatus to the sealing jaw using a screw connection. An ultrasonic sealing apparatus according to any one of claims 1 to 3, wherein the fixture (13) has a collar (20) for fixing the ultrasonic sealing apparatus to the sealing jaw, and the collar (20) which becomes the fixing position of the ultrasonic sealing apparatus and the sealing jaw is the nodal plane (26) farther from the sealing face. An ultrasonic sealing apparatus according to any one of claims 1 to 4, wherein the fixture (13) has a screw portion to be fixed to the horn (11) using a screw connection. An ultrasonic sealing apparatus according to any one of claims 1 to 4, wherein the fixture (13) is formed uninterruptedly with the horn (11). An ultrasonic sealing apparatus according to any one of claims 1 to 6, wherein the horn (11) has a slot (18) and/or slit (19) to reduce unwanted vibrations. An ultrasonic sealing apparatus according to any one of claims 1 to 7, wherein the horn (11) is made of a material having a longitudinal wave sonic speed of 4,000m/s or less. An ultrasonic sealing apparatus according to claim 8, wherein the material having a longitudinal wave sonic speed of 4,000m/s or less is a copper alloy. An ultrasonic sealing apparatus according to claim 9, wherein the copper alloy is phosphorous bronze. An ultrasonic sealing apparatus according to any one of claims 1 to 10, wherein the converter (12) has a screw portion to be fixed to the horn (11) or to the fixture (13) using a screw connection. An ultrasonic sealing apparatus according to any one of claims 1 to 11, wherein the plural converters (12) have a control means so that a uniform and suitably strong seal can be obtained at the sealing face (15). An ultrasonic sealing apparatus according to claims 3, 5 or 11, wherein the screw connection is a screw connection using a stud bolt (21). An ultrasonic sealing apparatus according to any one of claims 1 to 13, wherein the sealing face (15) is a sealing face having a ridge in the longitudinal direction of the sealing face (15) successively or intermittently. An ultrasonic sealing apparatus according to any one of claims 1 to 14, wherein the frequency ranges from 20KHz to 60KHz. An ultrasonic sealing apparatus according to claim 15, wherein the frequency is 40KHz. An ultrasonic sealing apparatus which includes a plurality of ultrasonic sealing devices (10) according to any one of claims 1 to 16. A transverse sealing apparatus comprising an ultrasonic sealing apparatus (10) according to any one of claims 1 to 17 and the sealing jaw (24) to which the ultrasonic sealing apparatus (10) is fixed and a driving means of the sealing jaw (24). A transverse sealing apparatus according to claim 18, wherein the sealing jaw (24) has a damper member for the horn (11).

Inventors: HAMAGUCHI TADAYOSHI, ISEKI TAKESHI, KUME SATOSHI, SHINOHARA MITSUHIKO, TAMAMOTO OSAMU, UEDA MICHIO, HAMAGUCHI, TADAYOSHI, ISEKI, TAKESHI, KUME, SATOSHI, SHINOHARA, MITSUHIKO, TAMAMOTO, OSAMU, UEDA, MICHIO, HAMAGUCHI, Tadayoshi Branson Ultrasonics, ISEKI, Takeshi Shikoku Kakoki Co., Ltd., KUME, Satoshi Shikoku Kakoki Co., Ltd., SHINOHARA, Mitsuhiko Shikoku Kakoki Co., Ltd., TAMAMOTO, Osamu Branson Ultrasonics, UEDA, Michio Shikoku Kakoki Co., Ltd.
Applicants: SHIKOKU KAKOKI CO LTD, SHIKOKU KAKOKI CO., LTD.
Application year: 1999
Main classification: B65B51
IPC codes: B65B51, B29C65