Abstract: A hot dip coating system comprises a bath of molten coating metal contained in a vessel having a strip passage opening located below the top surface of the bath. A metal strip is directed along a path extending through the strip passage opening and through the bath of molten coating metal, to coat the strip. A plug composed of solidified coating metal surrounds the strip downstream of the strip passage opening and is substantially stationary relative to the moving strip. The plug prevents escape of molten coating metal from the bath through the strip passage opening while permitting the strip to move along its path. Expedients are provided to chill the coating metal downstream of the strip passage opening to form and maintain the plug and to heat that part of the molten metal coating bath which is immediately downstream of the plug.

Abstract: A hot dip coating apparatus and method for coating a continuous steel strip, wire, or like continuous member with zinc, aluminum, tin, lead, or alloys of each. A molten coating bath is contained in a vessel having a bottom opening upwardly through which the steel member is directed. Magnetic containment devices located below the vessel's bottom opening prevent the escape of molten metal from the vessel through the opening. There are no guide rolls, or other rolls that act on the continuous steel member, in the bath.

Abstract: A strip casting apparatus comprises a pair of counter-rotating casting rolls having a vertically extending, arcuately tapering gap therebetween for containing a pool of molten metal. The gap has an open end near which is an electromagnetic dam for preventing the escape of molten metal through that open end. Various expedients are provided for improving the operation and efficiency of the dam. In one embodiment, projections of magnetic material extend from the dam in mutually overlapping relation with peripheral lips on the casting rolls. In another embodiment, the dam has a confining coil with a front surface (a) facing the open end of the gap and (b) having an arcuately tapering contour conforming to the contour of the gap.

Abstract: An electromagnetic confining apparatus prevents the escape of molten metal through the open end of a vertically extending gap between two horizontally extending members, such as two counter-rotating rolls of a continuous strip caster. The molten metal is located between the two members. The apparatus includes a vertically disposed coil through which flows a time-varying electric current to generate a first horizontal magnetic field adjacent the open end of the gap. A time-varying conduction current is directed through the pool of molten metal adjacent the open end of the gap, in a vertical direction opposite that of the current flow in the adjacent portion of the coil. The flow of conduction current through the molten metal pool generates a second horizontal magnetic field adjacent the open end of the gap and which augments the first horizontal magnetic field to provide a repulsive body pressure which urges the pool of molten metal inwardly away from the open end of the gap.

Abstract: A strip casting apparatus comprises a pair of counter-rotating casting rolls having a vertically extending, arcuately tapering gap therebetween for containing a pool of molten metal. The gap has an open end near which is an electromagnetic dam for preventing the escape of molten metal through that open end. Various expedients are provided for improving the operation and efficiency of the dam. In one embodiment, projections of magnetic material extend from the dam in mutually overlapping relation with peripheral lips on the casting rolls. In another embodiment, the dam has a confining coil with a front surface (a) facing the open end of the gap and (b) having an arcuately tapering contour conforming to the contour of the gap.

Abstract: A magnetic confining apparatus prevents the escape of molten metal through the open side of a vertically extending gap between two horizontally separated members and in which the molten metal is located. The apparatus includes a current conducting coil for generating a horizontal magnetic field and non-magnetic fins for concentrating the current in the surface of the coil which is closest to the open side of the gap. The magnetic field generated by the apparatus extends through the open side of the gap and exerts a confining pressure against the molten metal in the gap.

Abstract: Molten metal, in the gap between two counter-rotating rolls of a continuous strip-casting apparatus, is prevented from leaking out of an open side of the gap by a magnetic confining apparatus employing the proximity effect to produce a horizontal magnetic field extending through the open side of the gap. The apparatus includes structure for confining the magnetic field substantially to the open side of the gap and for preventing dissipation of the magnetic field away from the open side of the gap.

Abstract: A descending stream of molten metal is electromagnetically metered by a primary coil surrounding an upstream portion of the stream. Alternating electric current flows through the coil, and the frequency of that current is controlled to optimize the electromagnetic efficiency (magnetic pressure/power loss) of the electromagnetic metering system. Direct current can be added to the alternating current to also optimize electromagnetic efficiency.

Abstract: This relates to a method and apparatus for welding thin walled sheet steel tubular members of the type primarily intended for use as container bodies. The sheet steel may be provided with a suitable coating, such as tin plating, and is preferably heated by induction heating. The heated edge portions of a rounded tubular member are initially pressed together to effect bonding or welding, after which they are engaged by forge rolls to reduce the thickness of the resultant seam. The pressing together of the edge portions to initiate bonding is preferably effected between two coated surfaces, such as ceramic, with the pressure being applied by one of the members in the form of a spring loaded pin. When the electrical energy is induced into the edge portions, there is provided a secondary coil having a bore therethrough through which the rounded tubular member passes with the coil serving to size and guide the tubular member.

Abstract: An apparatus for applying tabs to end units wherein the tabs are in the form of an aluminum foil-plastic film laminate. A heating dial is provided for receiving tabs, rotating the tabs by indexing, and then applying the tabs. The heating dial includes a radio frequency transformer which includes a fixed primary winding and a segmented secondary winding which is rotatable as a unit together with heating elements secured thereto. The secondary winding segments are circumferentially spaced and each heating element is secured to two adjacent segments in bridging relation.

Abstract: An apparatus and method for applying metal foil-plastics material film laminate pull tabs to coated container units. A high frequency electrical energy force field is set up and induced into the metal of the pull tab with the resultant heating of the metal and the subsequent heating of the plastics material film to a bonding temperature together with the application of a magnetic repulsion force to the pull tab urging it away from its supporting head and into forced contact with the container unit.

Abstract: There has been developed end units for cans of the easy opening type wherein end panels of the end units are provided with patterns of holes to facilitate the dispensing of a product. The holes are closed by means of strips, preferably formed of plastics material, overlying the holes and being bonded to the metal of the end units adjacent the holes. It is preferred that the bonding of the strips be effected by heat. A special induction heater has been constructed which induces into the metal of the area to where the strips are to be bonded electrical energy which results in the heating of the metal. The heater is particularly constructed so as to compensate for the holes in the metal of the end units and thus a uniform heating of the metal over the area to which the strip is to be applied can be effected.

Abstract: There has been developed end units for cans of the easy opening type wherein end panels of the end units are provided with patterns of holes to facilitate the dispensing of a product. The holes are closed by means of strips, preferably formed of plastics material, overlying the holes and being bonded to the metal of the end units adjacent the holes. It is preferred that the bonding of the strips be effected by heat. A special induction heater has been constructed which induces into the metal of the area to where the strips are to be bonded electrical energy which results in the heating of the metal. The heater is particularly constructed so as to compensate for the holes in the metal of the end units and thus a uniform heating of the metal over the area to which the strip is to be applied can be effected.