US3742180A - High frequency cavity press - Google Patents

High frequency cavity press Download PDF

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Publication number
US3742180A
US3742180A US00147083A US3742180DA US3742180A US 3742180 A US3742180 A US 3742180A US 00147083 A US00147083 A US 00147083A US 3742180D A US3742180D A US 3742180DA US 3742180 A US3742180 A US 3742180A
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cavity
machine
platens
high frequency
platen
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US00147083A
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English (en)
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R Bradley
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USM Corp
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USM Corp
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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
    • 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
    • B29C65/14—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation
    • B29C65/1429—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface
    • B29C65/1464—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface making use of several radiators
    • B29C65/1467—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface making use of several radiators at the same time, i.e. simultaneous 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
    • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
    • B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
    • B29C35/08—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation
    • 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
    • B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
    • B29C59/02—Surface shaping of articles, e.g. embossing; Apparatus therefor by mechanical means, e.g. pressing
    • 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
    • B29C65/14—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation
    • B29C65/1403—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the type of electromagnetic or particle radiation
    • B29C65/1425—Microwave radiation
    • 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
    • B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
    • B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
    • B29C66/54—Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles
    • B29C66/542—Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles joining hollow covers or hollow bottoms to open ends of container bodies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/81—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps
    • B29C66/818—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the cooling constructional aspects, or by the thermal or electrical insulating or conducting constructional aspects of the welding jaws or of the clamps ; comprising means for compensating for the thermal expansion of the welding jaws or of the clamps
    • B29C66/8185—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the cooling constructional aspects, or by the thermal or electrical insulating or conducting constructional aspects of the welding jaws or of the clamps ; comprising means for compensating for the thermal expansion of the welding jaws or of the clamps comprising means for compensating for the thermal expansion of the welding jaws or of the clamps
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/81—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps
    • B29C66/818—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the cooling constructional aspects, or by the thermal or electrical insulating or conducting constructional aspects of the welding jaws or of the clamps ; comprising means for compensating for the thermal expansion of the welding jaws or of the clamps
    • B29C66/8187—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the cooling constructional aspects, or by the thermal or electrical insulating or conducting constructional aspects of the welding jaws or of the clamps ; comprising means for compensating for the thermal expansion of the welding jaws or of the clamps characterised by the electrical insulating constructional aspects
    • B29C66/81871—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the cooling constructional aspects, or by the thermal or electrical insulating or conducting constructional aspects of the welding jaws or of the clamps ; comprising means for compensating for the thermal expansion of the welding jaws or of the clamps characterised by the electrical insulating constructional aspects of the welding jaws
    • 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
    • B29C66/80—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
    • B29C66/832—Reciprocating joining or pressing tools
    • B29C66/8322—Joining or pressing tools reciprocating along one axis
    • 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
    • B29C66/87—Auxiliary operations or devices
    • B29C66/874—Safety measures or devices
    • B29C66/8742—Safety measures or devices for operators
    • 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
    • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
    • B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
    • B29C35/08—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation
    • B29C35/0805—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using electromagnetic radiation
    • B29C2035/0855—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using electromagnetic radiation using microwave
    • 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
    • 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
    • B29C66/13—Single flanged joints; Fin-type joints; Single hem joints; Edge joints; Interpenetrating fingered joints; Other specific particular designs of joint cross-sections not provided for in groups B29C66/11 - B29C66/12
    • B29C66/131—Single flanged joints, i.e. one of the parts to be joined being rigid and flanged in the joint area

Definitions

  • ABSTRACT An apparatus for applying pressure and a high frequency electric field to material comprising a cavity for [52] US. Cl. 219/10.81, 156/273 containing the electric field which encloses platens rah hat. Cl. atively movable to pressure to material placed [58] Field of Search 219/10.5 5, 10.61, between the platens The cavity electrically communi 219/1063 1 156/273 cates with the platens for supplying the contained electric field to the platens which, in turn, cooperate with [56] References C'ted each other to apply the field to the material between UN TED ST S PATENTS the platens.
  • the cavity and platens are also directly 3,205,114 9/1965 Gross 156/273 X coupled into the means for generating the electric field 3,469,054 9/1969 Serota 2l9/l0.6l as a resonant circuit.
  • This invention relates to an apparatus for applying pressure and a high frequency electric field to material.
  • Machines for applying a high frequency electric field to material are well known for their utility in heating dielectric material. Frequently, such high frequency heating machines are used on dielectric material which is heat softenable. Usually, a die is applied to the softened material to emboss the surface of the material.
  • the high frequencies which have been found useful for heating material are in the mega-Hertz range. These frequencies have corresponding wavelengths of a few meters. Such wavelengths are in the same order of magnitude as the physical dimensions of conveniently sized machines for working on the material. It is known that electromagnetic waves which have wavelengths similar in size to the physical dimensions of conductive parts of a machine on which they are impressed tend to radiate from the conductive parts.
  • Solving still another problem requires impedance matching or tuning the electric field generating and field applying components of a machine to each other. It has long been known that such tuning reduces the reflection of electric energy from the interface of electrical components toward the high frequency source. Here, reflected energy does not reach the'field applying means and thus reduces the efficiency of the machine. The size and the type of material between the platens effects the impedance and thus the reflection of the machine. Each change of material thus requires tuning of the machine for efficient operation of conventional machines.
  • a high frequency machine is provided with a cavity for containing an electric field and enclosing the parts of the machine which have high frequency energy on them.
  • the cavity is electrically conducting on its interior surface and designed so that substantially no high frequency energy appears on its exterior surface.
  • the cavity has an opening through which pieces of material to be operated upon may be placed between platens in the cavity.
  • a cover is positioned relative to the opening to contain the electric field at the opening. Platens are movably mounted within the cavity and cooperate to press the material placed between them. The platens are also electrically connected to the cavity to apply the high frequency field contained in the cavity to the material between the platens. Means for supplying a high frequency field to the cavity are provided.
  • the means for supplying the electric field to the cavity directly couple a high frequency power supply to the machine which itself serves as a resonant tank circuit to form the high frequency generator.
  • the material in the machine forms an integral part of the resonant circuit directly coupled into the high frequency generator.
  • changes in the material merely change the frequency of the machine.
  • a range of frequencies is acceptable for treating the material and, since the cavity prevents radiation,' governmental frequency regulations are not a problem.
  • the direct coupling of the machine or field applying component as part of the high frequency generator or field generating component eliminates energy reflection problems between field applying and generating components by combining them as one integral component. The cavity and direct coupling thus eliminate the need to tune the machine.
  • impedence characteristics for the machine resonant circuit relative to the internal impedance characteristics of the high frequency power supply such that the electric power of the high frequency field applied to the material is directly proportional to the effective area of the platens for a wide range of effective areas, while the potential difference across the platens or from one platen to the other is held constant.
  • the effective area of each platen is that surfacearea of each platen which affects the material between the platens.
  • the relative values of the characteristics which produce the direct proportionality are empirically determined. The direct proportionality results in the application to pieces of the material uniform except in area of constant electric field power per unit area regardless of the area of mate'- rial between the platens.
  • the power per unit area is the calories per second per unit area applied to the material; thus the elapsed time to heat the material from one temperature to any other temperature is independent of the area of the material.
  • the constant potential difference across the platens may conveniently be set below that potential which will permit arcing across the platens, a value dependent on ambient conditions at the press. In a high frequency heating machine such arcing may damage the material being heated.
  • FIG. 1 is a perspective view, partly in section, of an apparatus embodying the invention
  • FIG. 2 is a side view, partly in section, of the'apparatus shown in FIG. 1;
  • FIG. 3 is a side view, partly in section, of a support portion of the apparatus shown in FIG. 2.
  • a high frequency heating machine embodying the instant invention has a cavity generally indicated at enclosing an operating portion of the machine and electrically conducting on its interior surfaces.
  • the cavity has an opening indicated generally at 12 to provide access into the cavity for pieces of material 14 to be heated in the machine.
  • a platen 16 is seen to be mounted within the cavity on a support structure indicated generally at 18. Another platen is mounted for movement relative to the first platen to press material 14 between the platens in the cavity.
  • a composite cover 22 for the cavity opening 12 is secured to the movable platen. When the platens engage and press the material, the cover closes the opening 12 to contain an electric field in the cavity.
  • the electric field is applied to the cavity through input link 23 from a high frequency power supply (not shown) directly coupled to the cavity.
  • the platen l6 electrically communicates with the cavity and the second platen also electrically communicates with the cavity through the composite cover to apply the electric field in the cavity to the material 14 between the platens.
  • the electric field applied to the material by the platens dielectrically heats lossy material.
  • a die 25 is placed between the platens to emboss the heated material when it is pressed by the platens.
  • the cavity 10 is a box-like structure having interior walls 40 and a bottom 42 made from an electrically conducting material such as copper. At the top of the box is the opening 12 through which material to be heated is inserted into the cavity. Additional walls 44 project from a central portion of the cavity bottom 42 to enclose a central support shaft 46 of the platen support structure 18. The walls 44 shield the shaft 46 from the electric field in the cavity. Supporting walls 48 physically and electrically connect the upper end of walls 44 to the periphery of the first platen 16. The physical connection of the walls 48 to the platen 16 supports the entire cavity 10 which is not supportingly connected to any other part of the machine to isolate the cavity and contain the electric field in the cavity. The contained electric field does not substantially radiate into the space adjacent the machine.
  • the support structure 18 supports the first platen l6 and thus also supports the cavity 10 connected to the platen.
  • the support structure 18 comprises the central support shaft 46 and additional support members 50 which project through close fitting holes 51 (FIG. 3) in the cavity base 42 and supporting walls 48 to support the first platen 16 near its periphery.
  • the central support 46 provide the main physical load bearing support while the members prevent deflection of the platen 16 near its periphery, supports of either the types illustrated by 46 and 50 may be used separately or in any other desired combination.
  • the support shaft 46 may be made from any material selected for its supporting strength because the enclosing walls 44 and 48 of the cavity prevent any of the electric field in the cavity from reaching the support. Thus, the central support will not conduct any part of the electric field from the cavity to the space surrounding the machine.
  • the support members 50 must be made from an electrically non-conducting material such as ceramic to prevent them from conducting the electric field from within the cavity to the space outside the cavity.
  • the holes 51 in the cavity walls 42 and 48 through which the support members 50 project should be sufficiently close fitting to cooperate with the members 50 to contain the electric field in the cavity.
  • the platen 116 is mounted on the support structure 18 to provide a rigid platform against which the movable platen 20 can press the material 14.
  • the platen 16 may be made from a strong, rigid material such as steel.
  • the platen 16 supports on its upper surface a panel 60, of silicone glass or the like, which extends beyond the edges of the platen to the walls 40 of the cavity.
  • the panel thus serves as an insulator plate and as a cover for the opening in the cavity to exclude dust and foreign matter.
  • the platen i6 and panel 60 preferably support a second panel 62 which is substantially coextensive with the area of the platen.
  • the second panel 62 may be made of silicone rubber or the like and provides a resilient surface on which the material 14 may be placed.
  • the first and second panels also affect the electrical capacitance between the platens 16 and 20.
  • the platen 20 is mounted for vertical movement relative to the platen 16 and is moved by a fluid operated cylinder 63 to press the work piece 14 between the platens.
  • Electrically operated thermal-heating elements 64 are embedded interior the platen 20 and are directly connected to a source of electric power (not shown) to thermally heat the second platen.
  • the elements 64 are embedded in the platen 20 sufficiently far from the inner surface 65 of the platen 20 so that no high frequency energy reaches the elements due to the known skin effect phenomena in which high frequency energy appears only on the surface of conductors. Thus no filters or other devices are needed to protect electrically connected external components, here the electric power source for the heating elements 64, from the high frequency energy in the cavity.
  • a die 25 is secured to the movable platen 20 to engage the material 14 when the platen 20 is moved toward the fixed platen 16.
  • the material engaging surface 66 of the die may be embossed with any characteristics which it is desired to impress upon the material 14. Because the die surface 66 more closely approaches the fixed platen 16 than does the movable platen 20, the area of the die surface 66 alters the capacitance between the platens by altering the capacitively effective area of the parallel plate platen structure creating the capacitance. The die area thus forms the effective platen area.
  • a flange 69 electrically connects the die to the cover 22.
  • the composite cover 22 is secured at an inner edge 70 to the platen 20 and flange 69 and is secured at its outer edge by a bracket 68 to an outer cover 71.
  • cover 22 is made from electrically conducting material and has a jog 72 intermediate its edges to permit the cover to bend to accommodate thermal expansion of the platen 16 when it is thermally heated by the heating elements 64.
  • the support bracket 68 also electrically connects the cover 22 to contact members 74 which extend around the entire periphery of the cover. When the cover is closed and the die 25 engages the material 14 on the panel 62, the contact members electrically connect the cover with cooperative contact members 76 electrically connected to the walls 40 of the cavity. Through cooperative contacts 74 and 76 the cover electrically connects the walls 40 of the cavity to the movable platen 20 and die 25 to close the cavity opening 12 and contain the electric field within the cavity.
  • a high frequency electric energy power supply (not shown) is directly coupled to the top surface of the first platen by a lug (not shown) of input terminal 23.
  • the input terminal includes capacitor 79 which blocks direct current input to the cavity.
  • Most of the high frequency energy from the input radiates as a rapidly changing electric field between the surface of the fixed platen and the die and movable platen.
  • the die and movable platen electrically communicate with the cavity walls, the interior surfaces of which electrically communicate with a grounding plate 80. Only the interior surface of the electrically communicating elements need be considered since by a well known phenomena, commonly called skin effect, all the high frequency energy on the cavity remains on the surface of the cavity. Some of the high frequency energy circulates in the space enclosed by the cavity.
  • a pick up coil 82 to provide feedback for the high frequency power supply.
  • the coil 82 is of an oriented type, such as the loop coil shown, so that the feedback may be varied by rotating the coil to affect generator performance in a well known manner.
  • the interior conducting surface of the cavity is an inductance at the high frequencies employed in the machine.
  • the parallel plate structure of the platens, panels, material and die is capacitive and together with the associated capacitor 79 are in parallel with the cavity.
  • the machine thus forms an inductive-capacitive parallel resonant tank circuit directly coupled into the high frequency generator. Direct coupling is not by transmission line, but by direct link to the power supply portion of the generator.
  • a high frequency power supply cornprising a plate loaded vacuum tube having DC characteristics in which the plate current is 2 amps; grid current, one-half amp; plate voltage, 3,400 volts and gain, mu 30; and a cavity 10 having a bottom 42-l7 X l7 inches, walls 40-l0 inches high, walls 44-9 inches high and walls 48-4 k inches wide, panels 60 and 62% inches thick each and an associated capacitor 79 of 0.0005 microfarads.
  • a machine for applying a high frequency electric field and pressure to material which comprises:
  • a cover positioned relative to the opening for containing the field in the cavity at the opening;
  • the platen support means comprises a shaft projecting through a hole in the cavity defining means to one of the platens and enclosed by additional walls of the cavity extending from the platen on the shaft to the hole.
  • the platen support means comprises an electrically non-conducting member projecting through a hole in the cavity defining means to the platen on the member.
  • a machine for applying a high frequency electric field to material comprising:
  • a machine for applying a high frequency electric field and pressure to material comprising:
  • a generator for high frequency electric energy two platens electrically connected to the generator for applying the energy as an electric field and movable for applying the pressure to the material between the platens; and means electrically connected to the generator and platens for providing the power of the field in direct proportion to an effective area of the platens.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Thermal Sciences (AREA)
  • Electromagnetism (AREA)
  • Toxicology (AREA)
  • Fluid Mechanics (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Constitution Of High-Frequency Heating (AREA)
  • Press Drives And Press Lines (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
US00147083A 1971-05-26 1971-05-26 High frequency cavity press Expired - Lifetime US3742180A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US14708371A 1971-05-26 1971-05-26

Publications (1)

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US3742180A true US3742180A (en) 1973-06-26

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US00147083A Expired - Lifetime US3742180A (en) 1971-05-26 1971-05-26 High frequency cavity press

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US (1) US3742180A (fr)
AT (1) AT329162B (fr)
AU (1) AU468042B2 (fr)
CA (1) CA947824A (fr)
CH (1) CH547599A (fr)
DD (1) DD100429A5 (fr)
DE (1) DE2224081A1 (fr)
ES (1) ES403593A1 (fr)
FR (1) FR2139073B1 (fr)
GB (1) GB1381635A (fr)
HU (1) HU168327B (fr)
IT (1) IT955780B (fr)
NL (1) NL7206881A (fr)
PL (1) PL81986B1 (fr)
SE (1) SE373310B (fr)
SU (1) SU558627A3 (fr)
ZA (1) ZA723588B (fr)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3845269A (en) * 1973-05-24 1974-10-29 Usm Corp Adjustable timing device
US4036676A (en) * 1975-04-14 1977-07-19 William Pennington Heat sealing of plastic sheets
US4205210A (en) * 1974-12-20 1980-05-27 Usm Corporation High frequency cavity press
US4362918A (en) * 1980-10-30 1982-12-07 Simon Rabin Radiation absorbing apparatus
US5476634A (en) * 1990-03-30 1995-12-19 Iit Research Institute Method and apparatus for rendering medical materials safe
US5508004A (en) * 1989-10-13 1996-04-16 Stericycle, Inc. Apparatus and method for processing medical waste
US5516466A (en) * 1994-10-27 1996-05-14 Armstrong International, Inc. Steam humidifier system
US5641423A (en) * 1995-03-23 1997-06-24 Stericycle, Inc. Radio frequency heating apparatus for rendering medical materials
US5709842A (en) * 1989-10-13 1998-01-20 Stericycle, Inc. Apparatus and method for processing medical waste
US5973308A (en) * 1997-08-05 1999-10-26 Rockwell Science Center, Inc. Efficient dielectric heater
US6248985B1 (en) 1998-06-01 2001-06-19 Stericycle, Inc. Apparatus and method for the disinfection of medical waste in a continuous manner
WO2003077600A1 (fr) * 2002-03-06 2003-09-18 State Technology, Inc. Appareil pour tubes commande par microprocesseur a emissions radiofrequences reduites
US20060037956A1 (en) * 2004-08-17 2006-02-23 State Technology, Inc. Method and apparatus for closing or severing a tube using a controllable closure force

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3205114A (en) * 1962-01-26 1965-09-07 Sealomatic Electronics Corp Heat sealing and vacuum operated die cutting device
US3357108A (en) * 1966-05-11 1967-12-12 Fitchburg Paper Mobile dielectric drying apparatus with energy source coupling means
US3401248A (en) * 1965-10-20 1968-09-10 Ford Motor Co Dielectric die
US3469054A (en) * 1967-03-15 1969-09-23 Bangor Punta Operations Inc Shielded dielectric heating apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3205114A (en) * 1962-01-26 1965-09-07 Sealomatic Electronics Corp Heat sealing and vacuum operated die cutting device
US3401248A (en) * 1965-10-20 1968-09-10 Ford Motor Co Dielectric die
US3357108A (en) * 1966-05-11 1967-12-12 Fitchburg Paper Mobile dielectric drying apparatus with energy source coupling means
US3469054A (en) * 1967-03-15 1969-09-23 Bangor Punta Operations Inc Shielded dielectric heating apparatus

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3845269A (en) * 1973-05-24 1974-10-29 Usm Corp Adjustable timing device
US4205210A (en) * 1974-12-20 1980-05-27 Usm Corporation High frequency cavity press
US4036676A (en) * 1975-04-14 1977-07-19 William Pennington Heat sealing of plastic sheets
US4362918A (en) * 1980-10-30 1982-12-07 Simon Rabin Radiation absorbing apparatus
US5833922A (en) * 1989-10-13 1998-11-10 Stericycle, Inc. Apparatus and method for processing medical waste
US5508004A (en) * 1989-10-13 1996-04-16 Stericycle, Inc. Apparatus and method for processing medical waste
US5709842A (en) * 1989-10-13 1998-01-20 Stericycle, Inc. Apparatus and method for processing medical waste
US5830419A (en) * 1989-10-13 1998-11-03 Stericycle, Inc. Apparatus and method for processing medical waste
US5476634A (en) * 1990-03-30 1995-12-19 Iit Research Institute Method and apparatus for rendering medical materials safe
US5516466A (en) * 1994-10-27 1996-05-14 Armstrong International, Inc. Steam humidifier system
US5641423A (en) * 1995-03-23 1997-06-24 Stericycle, Inc. Radio frequency heating apparatus for rendering medical materials
US5973308A (en) * 1997-08-05 1999-10-26 Rockwell Science Center, Inc. Efficient dielectric heater
US6344638B1 (en) 1998-06-01 2002-02-05 Stericycle, Inc. Method for the disinfection of medical waste in a continuous manner
US6248985B1 (en) 1998-06-01 2001-06-19 Stericycle, Inc. Apparatus and method for the disinfection of medical waste in a continuous manner
WO2003077600A1 (fr) * 2002-03-06 2003-09-18 State Technology, Inc. Appareil pour tubes commande par microprocesseur a emissions radiofrequences reduites
US6794624B2 (en) 2002-03-06 2004-09-21 John W. Dozier Microprocessor controlled tube apparatus having reduced radio frequency emanations
GB2402592A (en) * 2002-03-06 2004-12-08 State Technology Inc Microprocessor controlled tube apparatus having reduced radio frequency emanations
US20050016994A1 (en) * 2002-03-06 2005-01-27 Dozier John W. Microprocessor controlled tube apparatus having reduced radio frequency emanations
GB2402592B (en) * 2002-03-06 2006-04-12 State Technology Inc Tube apparatus for detecting successful or failed tube operations
US7342209B2 (en) 2002-03-06 2008-03-11 State Technology, Inc. Microprocessor controlled tube apparatus having reduced radio frequency emanations
US20060037956A1 (en) * 2004-08-17 2006-02-23 State Technology, Inc. Method and apparatus for closing or severing a tube using a controllable closure force
US7326898B2 (en) 2004-08-17 2008-02-05 State Technology, Inc. Method and apparatus for closing or severing a tube using a controllable closure force

Also Published As

Publication number Publication date
CA947824A (en) 1974-05-21
AT329162B (de) 1976-04-26
PL81986B1 (fr) 1975-10-31
DE2224081A1 (de) 1972-12-07
ES403593A1 (es) 1975-05-16
CH547599A (de) 1974-03-29
ATA454272A (de) 1975-07-15
AU4265372A (en) 1973-11-29
AU468042B2 (en) 1975-12-18
GB1381635A (en) 1975-01-22
DD100429A5 (fr) 1973-09-20
SU558627A3 (ru) 1977-05-15
FR2139073B1 (fr) 1976-01-16
ZA723588B (en) 1973-04-25
HU168327B (fr) 1976-03-28
NL7206881A (fr) 1972-11-28
SE373310B (sv) 1975-02-03
FR2139073A1 (fr) 1973-01-05
IT955780B (it) 1973-09-29

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