Abstract: This disclosure relates to an apparatus for and a method of electrical inductance heating of metal strips and slabs. The heating method involves a plurality of pairs of individual electrical coils exposed on opposite sides of a path of movement of a metal strip or slab wherein the coils are elongated longitudinally of the path of movement of the metal member, such as a strip or slab, whereby the pattern of heating is in the way of stripes. Further, to eliminate any pulsing of current within the strip or slab being heated, each coil is spaced from a transversely adjacent coil a distance corresponding substantially to the effective heating width of that coil. The coils of a next longitudinal adjacent set of coils are transversely offset relative to the coils of the first mentioned set of coils so that each coil of the second set is aligned with a space between coils of the first set. This provides for a heating of the strip or slab in stripes and prevents overheating of the edges of the strip or slab.

Abstract: This relates to the heating of thick slabs for rolling and like purposes wherein there is a complete penetration of the slab by induced electrical energy wherein the starting current frequency is very low and wherein a maximum heating is obtained by increasing the current frequency to control through penetration of the induced current in the slab as the temperature of the slab rises and thus the restivity of the metal of the slab increases. Several heating systems are envisioned. These include a heating system of a length corresponding to the length of the slab and wherein the slab is stationary during the heating to the desired temperature, after which the slab is moved out of the heating apparatus. The second arrangement is similar to the first, but wherein a lower coil arrangement moves relative to the upper coil arrangement so as to remove and expose a heated slab. In these two systems, the frequency is progressively increased.

Abstract: This relates to a sealing head for sealing lids to cartons. The sealing head is provided with suction heads or cups for receiving a lid from a lid supply and depositing such lid in position on a carton which is mounted in a nest. The sealing head is provided with a seal member which forms the seal with a nest carrying a carton so that a vacuum may be drawn within the nest both within and around the carton. Thereafter, the sealing head provides an inert gas, such as nitrogen, to fill the carton with the inert gas, after which a support further sealing head moves the sealing head down further so that a lower edge of a projecting induction heating coil will clamp a lid against a carton and effect a heat bonding of the lid to the carton. The sealing head is self contained and has a fitting including a plurality of electrical prongs and fluid line sockets for coupling the sealing head to a receptacle.

Abstract: This relates to an induction heating coil which is of a single turn construction and particularly configurated for inducing electrical energy into a metal foil barrier layer of a laminated container closure for effecting heat bonding of the closure to a container in a preselected seal pattern. The seal pattern contains either one corner or the closure is provided with a projecting pull tab wherein there is a greater heating requirement and thus a requirement for the induction of higher electrical energy into the closure. The need for the induction of a greater amount of heat into the closure at a corner or the location of a projecting pull tab is provided for by reducing the cross section of the heating coil at the location of the greater heat requirement. The reduction in cross section is primarily effected by forming a notch in the heating coil. If desired, a closer control of the heating effect of the coil may be obtained by positioning in the notch a ferrite insert.

Abstract: This relates to the induction heating of metal shapes and coils of metal strip wherein the element to be heated functions as a shorted out armature of a D.C. generator. Either the metal shape to be heated or field forming magnets are moved relative to each other wherein the metal shape cuts the flux field to effect an induced generation of electricity within the shape. The frequency of the induced current is such wherein the electrical energy is induced into the metal shape on the order of one third of the thickness of that shape wherein a most efficient conduction of the heat from the electrical energy is effected with a minimum heat loss to the atmosphere. The voltage involved is low while there is a very high amperance. The frequency of the induced current will normally be on the order of one to ten hertz and less than sixty hertz. The relative movement between the field and the shape to be heated may be rotary or linear.

Abstract: This relates to an induction heating coil which is of a single turn construction and particularly configurated for inducing electrical energy into a metal foil barrier layer of a laminated container closure for effecting heat bonding of the closure to a container in a preselected seal pattern. The seal pattern contains either one corner or the closure is provided with a projecting pull tab wherein there is a greater heating requirement and thus a requirement for the induction of higher electrical energy into the closure. The need for the induction of a greater amount of heat into the closure at a corner or the location of a projecting pull tab is provided for by reducing the cross section of the heating coil at the location of the greater heat requirement. The reduction in cross section is primarily effected by forming a notch in the heating coil. If desired, a closer control of the heating effect of the coil may be obtained by positioning in the notch a ferrite insert.

Abstract: This relates to an induction heating coil unit which includes a conventional one turn induction coil which has associated therewith a laminated core. The core is formed of electrically conductive metal members and insulating, preferably plastic, members. The core members are arranged in stacked relation over the coil and then the core is normally potted in a supporting structure preferably of a plastic material. Where maximum heat is required, the concentration of the conductive members is increased. By varying the ratio of the conductive members to the insulating spacer members, the desired electrical energy may be induced into a closure having an intermediate metal barrier layer so as to control the heating of the closure and thus the heat bonding of the closure to an associated container.

Abstract: This relates to an induction heating unit which is particularly constructed for inducing electrical energy into the periphery of a metal foil barrier layer of a closure for a container to thereby heat the closure and heat bond the closure to the container. In lieu of the customary single turn coil, there is provided a multiple turn coil which is mounted in one of two opposing U-sections of a core. The U-sections may either be formed of ferrite or be of a laminated construction. First legs of the U-sections are utilized to clamp a closure to a container while there will be an air gap between the other opposed legs of the U-sections. Heating may be controlled by either varying the air gap or by varying the ratio of electrically conductive members with insulating spacers.

Abstract: This relates to an apparatus for heat bonding a lid having a metallic layer to a plastic container. The container, filled with a product, is seated in a nest and a lid is seated in place thereon. There is at least one corner on the lid and projecting from that corner is a pull tab. An induction heating unit is associated with the lid and presses it tightly against the container while inducing electrical energy under controlled conditions into the metal layer. The induction heating unit is provided with a specific arrangement of ferrite members for controlling the induction of current into the metallic layer. The ferrite parts in conjunction with the induction coil serve to concentrate the induced electrical energy into substantial alignment with the induction coil notwithstanding the fact that there is a corner and there is projecting from the corner of the lid a pull tab.

Abstract: This relates to an induction heating apparatus which is particularly constructed and configurated so as to induce electrical current into a cylindrical portion of a member while the member moves along a path and is free of being rotated. The induction heading apparatus, by applying a uniform circumferential heating current, permits the device being heated to be pressed down into position relative to a companion device. The apparatus particularly relates to the heating of a heat softenable adhesive joining together telescoped cylindrical portions of a container and the proper seating of the upper container end unit on the container body and assures a uniform bond between the telescoped portions. This abstract forms no part of the specification of this application and is not to be construed as limiting the claims of the application.

Abstract: This relates to a system for reheating adhesive bonding an end unit to a can body under controlled conditions and then further telescoping the end unit relative to the can body to assure proper adhesive flow relative to the can body. An end unit has been previously applied to a can body and is bonded thereto by a hot melt adhesive which has partially set. The end unit is not in its fully telescoped position. The adhesive is reheated to a temperature wherein the adhesive has the desired fluidity, after which the adhesive is maintained at this temperature and the end unit is moved to its fully telescoped position with a bead of the adhesive flowing over and encapsulating the raw edge of the can body.