Abstract: An apparatus for soldering printed circuit boards includes carriers each adapted for holding a printed circuit board and conveyed successively through a soldering zone to dip each printed circuit board into molten solder contained in a vessel. The vessel is disposed between a pair of laterally spaced apart track members which are engageable two front and two rear wheels of the carrier to support the carrier and the printed circuit board generally in the horizontal state throughout the movement thereof along the track members. Each track member has a first and a second depression at such locations that the two front and the two rear wheels can simultaneously position in the first and second depressions, respectively. Each depression has a depth sufficient to permit the printed circuit board to be dipped into the molten solder when the four wheels travel therealong.

Abstract: A conveyor device containing transport frames, each of which is structured for receiving a printed circuit or wiring board carrying circuit components and guided at their leading and their trailing corners by related guide tracks, leads the transport frames to a solder bath, where the transport device lowers the transport frames together with the printed circuit boards towards the solder bath and again raises the same therefrom. During the course of travel of a transport frame containing a printed circuit board carrying one or more of the circuit components through the solder bath one side of the printed circuit board is immersed into the solder bath and then again lifted out of the solder bath.

Abstract: A method is provided for teem-welding metals, preferably light metals, particularly aluminium and its alloys, in which the metal, during its introduction into a casting mould, is caused to form one or more metal jets which are directed as far as possible at right-angles to and concentrated against the surfaces to be melted of the workpiece or workpieces. There is used a mould of such volume and with such an arrangement of the workpiece or workpieces therein, that the desired melting is achieved with that quantity of metal which, as the process proceeds, accumulates in and fills the mould, which quantity constitutes all the metal introduced into the mould.

Abstract: Apparatus is disclosed herein for extending the length of a trailing wave of a double sided laminar wave of solder by the use of a dam in an oil intermix wave soldering system to create a dead zone while still being able to remove oil from the surface of the dead zone area on a continuous basis to prevent contaminants from interfering with soldering operations.

Abstract: In the wave soldering of terminals of an electrical device, such as a miniaturized printed circuit board assembly, the board is moved along a predetermined path so that it initially engages a first solder wave flowing counter to the direction of the board movement and subsequently engages a second solder wave flowing in the direction of board movement. The velocity of the solder in each of the solder waves is controlled independently by having separate independent pumping systems. Thus, the solder waves can be set at different independent velocities to achieve proper soldering of the terminals and associated conductor paths while reducing crossovers or bridges (i.e., shorts) between the terminals and the conductor paths as a result of the close spacing thereof.

Abstract: A mass soldering system is described in which a standing wave of molten solder is formed. The solder wave is characterized by having a substantially horizontal crest, and the wave has varying pressures along its flow path. In a preferred embodiment of the invention the wave pressures are varied to produce a wave having increasing pressure along its flow path whereby a substantially uni-directional wave may be formed which is highest adjacent its rear.

Abstract: A mass wave soldering system is described in which a standing wave of molten solder is formed from a static head of solder. The system comprises a soldering apparatus which has a two-compartment solder reservoir. The first compartment is designed to hold a first portion of the solder supply at a first liquid level with a layer of oil floating on the solder therein. The second compartment is designed for holding a second portion of the solder supply at a second liquid level above the first liquid level with a layer of oil floating on the solder therein. A sump and nozzle are positioned in the first compartment so that the sump is partially submerged in the molten solder therein, with the nozzle above the solder and oil levels therein, but below the solder and oil levels in the second compartment.

Abstract: Workpieces, such as printed circuit boards, are processed by passing the boards in contact with a standing wave of molten solder formed by circulating molten solder upwardly through a nozzle to overflow at least one edge thereof to form a standing wave which is accelerated by gravity so as normally to have an upper surface ballistically curved in the direction of flow. In accordance with the invention, the undersurface of the standing wave is supported to have a ballistic curvature, in the direction of flow, such that a major portion of the upper surface of the wave is substantially planar with the cross-sectional area of the wave varying, in the direction of flow, in a manner similar to the variation of the cross-sectional area of an unsupported wave following a ballistic curve in is trajectory.