Abstract: Apparatus for soldering surface mounted devices to printed circuit boards utilizing a combination of forced convection and infrared radiation. Fans are disposed in each heating zone which force gas through a heating plate which heats the air, emits infrared radiation for heating of printed circuit boards, and establishes a flow pattern for the gas. Flows are controlled in each zone by selectively introducing unheated gas into each zone, and by selectively exhausting gas from each zone. The volume of gas introduced and exhausted from each zone can be controlled. Closures are provided in the return channels to the low pressure side of the fan for controlling the volume of gas recirculated from the conveyor. Flow is controlled such that cooler air is always introduced into the zones which have a lower temperature and is exhausted from zones which have higher temperatures.

Abstract: Apparatus for soldering surface mounted devices to printed circuit boards utilizing a combination of forced convection and infrared radiation. Fans are disposed in each heating zone which force gas through a heating plate which heats the air, emits infrared radiation for heating of printed circuit boards, and establishes a flow pattern for the gas. Flows are controlled in each zone by selectively introducing unheated gas into each zone, and by selectively exhausting gas from each zone. The volume of gas introduced and exhausted from each zone can be controlled. Closures are provided in the return channels to the low pressure side of the fan for controlling the volume of gas recirculated from the conveyor. Flow is controlled such that cooler air is always introduced into the zones which have a lower temperature and is exhausted from zones which have higher temperatures.

Abstract: A door latching arrangement is provided for an enclosure that stores energy at each position in a range of opening positions such that if the door is manipulated to permit opening, sufficient energy is available to permit the automatic latching of the door upon closing. The door latching arrangement includes a movable latch arm which in a specific arrangement is carried by the door. The latch arm is biased to engage a projection or hasp of the enclosure when the door is closed. A latch retaining member carried by the door is arranged to interact with the latch arm to prevent the engagement of the latch arm by the hasp. Movement of the latch arm to disengaged the hasp, coupled with the opening of the door to separate the hasp and the latch retaining member, results in the latch retaining member moving to a position to interact with and retain the latch arm.

Abstract: A vapor phase system for soldering of a workpiece. A vessel for containing an electronic liquid which is heated to generate a zone of saturated vapor. A first inclined throat communicates with the vessel and a solder pot is located within the vessel. The solder pot including a reservoir for containing molten solder, a second throat aligned with the first throat and communicating at one end with molten solder contained in the reservoir means and communicating at the other end with the saturated vapor, molten solder contained in the reservoir means is pumped through the second throat and is captured by the reservoir and a conveyor carries work product through the first throat, through the saturated vapor and into the second throat whereby the work product will become immersed in the molten solder contained within the second throat.

Abstract: A linear operating mechanism is provided for operating one or more electrical switches or interrupters, the mechanism selectively closing the switch via movement of a switch operating member and immediately thereafter being capable of opening the switch as required. The operating mechanism includes a carriage that is movable over a linear path to charge an opening spring and a closing spring. The switch operating member is movable along an axis parallel to or coincident with the path of the carriage. The opening spring and the closing springs are disposed about a common axis parallel to the movement of the carriage and the switch operating member. A first latch arrangement is provided for preventing switch-closing movement of the switch operating member when the switch is open and the first latch arrangement is engaged.

Abstract: An arrangement including an insulative support column provides independent rotary and linear drive outputs for the operation of electrical switches, circuit interrupters and/or disconnects or the like. A first, linear drive linkage provides translating motion at a first output in response to linear translating motion at a first input. The linear drive arrangement is provided by an elongated, insulative operating member that is disposed within an elongated bore of the insulative support column, with the operating member extending through the top and bottom ends of the column. A second, rotary drive output is provided by rotation of the support column. The column fixedly carries a lower base member which is rotatably supported within a base housing. The operating member extends through and exits the base member and cooperates with a bearing carried by the base member. The lower end of the operating member is coupled to the linear drive linkage input.

Abstract: A female interrupting contact for a current-interrupting unit includes a smoothly contoured, apertured pressure ring which is held in a groove formed in the wall of a bore through a contact body. A spring in the groove maintains the ring to one side of the bore so that the aperture is normally misaligned with the path of a male contact through the bore. When the male contact enters the aperture, it moves the ring against the action of the spring to align the aperture with its path. This alignment effects intimate sliding engagement between the male contact and both the ring and the wall of the bore, one or both of the latter of which are conductive so that a reliable electrical path through the contacts and the interrupting unit is established.

Abstract: A solder leveling system for use in vapor phase soldering of printed wiring boards. A transport system operating in a near-horizontal mode moves the board to be solder coated through a vapor zone in a chamber having a solder pot which has a throat in line with the plane of the transport system. The near-horizontal movement through the vapor and into and out of the solder pot prevents solder sag and permits control of the thickness of solder deposited on the opposing board surfaces. Leveling nozzles are positioned in a vapor-filled chamber astride the transport system between the solder pot and the chamber throat. Perpendicular nozzle offset distance from the board and nozzle angle are adjustable. Preferably one nozzle projects a stream normal to the board, with the other nozzle projecting a grazing stream for clearing through holes. A nozzle flow rate corresponding to a predetermined energy threshold provides reliable hole clearing.

Abstract: A high-voltage circuit-interrupting device includes a replaceable container of pressurized arc-extinguishing fluid. A fluid port of the container is closed by a puncturable seal. When an overcurrent occurs in the circuit, the seal is punctured before interrupting contacts of the device open so that the fluid is already flowing when an arc forms between the contacts. Overcurrents are sensed by either a fusible element or a current transformer. Fluid flow before contact opening is achieved by mechanical facilities responsive to the melting of the fusible element or the output of the transformer. The entire device--including the container, the overcurrent sensor and the mechanical facilities--is at the voltage of the circuit.

Abstract: In high-voltage switchgear, apparatus for preventing two switches from being closed at the same time to prevent their being electrically paralleled relative to a common bus. The position of each switch is mimicked by a rotatable cam having a notch. When either switch closes while the other switch is fully open, its cam moves a member into the path of the notch in the other cam which is blocked from rotating, preventing the other switch from closing. If both switches attempt to close simultaneously, the member either blocks both cams or blocks one while permitting the other to rotate. If one switch attempts to close while the other switch is closed, and if the one switch continues to attempt closure through the time the other switch opens, its cam continues to be blocked until the one switch is returned to full open.

Abstract: A pre-insertion resistor mechanism for a circuit interrupting device of the type which has a pair of normally-engaged contacts. One of the contacts is movable relative to the other contact in an arc-extinguishing environment to selectively separate the contacts to open a gap therebetween to effect circuit interruption. The contacts are continuously, electrically connected to respective, opposed circuit-connectable terminals on the device. The pre-insertion resistor mechanism includes a pre-insertion resistor electrically connected at one end to one of the terminals. The other end of the resistor carries a stationary electrode. A movable electrode assembly which is electrically connected to the other terminal is mechanically coupled to the movable contact so that upon movement thereof to open the gap, the movable electrode simultaneously separates from the stationary electrode.