Abstract: A probeless energy delivery controller for a resistance spot welding system includes a power supply module that generates a first current and a power delivery module configured to generate a second current from the first current. The current is delivered to a first electrode and a second electrode that have at least two weld pieces interposed there-between. As the current flows through the weld pieces, the resistance and temperature of the weld pieces increase such that the weld pieces melt. The system further includes a voltage control module that receives a current reading indicating a value of the second current, estimates a resistance of the weld pieces based on the value of the second current, and determines a phase angle for setting a voltage outputted by the power supply module based on the estimated resistance and a power profile. The power supply module generates the first current based on the phase angle.

Abstract: A probeless energy delivery controller for a resistance spot welding system includes a power supply module that generates a first current and a power delivery module configured to generate a second current from the first current. The current is delivered to a first electrode and a second electrode that have at least two weld pieces interposed there-between. As the current flows through the weld pieces, the resistance and temperature of the weld pieces increase such that the weld pieces weld together. The system further includes a voltage control module that receives a current reading indicating a value of the second current, estimates a resistance of the weld pieces based on the value of the second current, and determines a phase angle for setting a voltage outputted by the power supply module based on the estimated resistance and a power profile. The power supply module generates the first current based on the phase angle.

Abstract: A welding method and apparatus are disclosed wherein a plurality of stacks of metal sheets are clamped together in sequence at a welding site between a pair of electrode caps across which welding current is supplied to spot weld together the sheets in each of the stacks in a series of welding operations in a production run. The electrode caps are pressed against the sheets in each of the stacks when each of the stacks is at the welding site with an applied force that includes a closing force to clamp the sheets together in a surface-to-surface interface fit plus a predetermined interjoint force that is increased progressively throughout the production run.

Abstract: A method and system for controlling a welding system collects material thickness data and material type data for a plurality of materials to be welded. A non-linear power profile is generated having a discrete stepped approximation of power over a period of time based on the material thickness data and the material type data to produce a desired current amount at a specific time during welding of the plurality of materials.

Abstract: A method for estimating weld nugget diameter includes receiving current and voltage inputs, a time input, and a force input. In certain embodiments, the method also uses other weld parameters including type of material, type of stack, stack thickness, applied force, preheat current, RMS value of weld current, weld level, and weld time. The method further determines a resistance curve based on the current and voltage inputs, and time input. It also derives parameters from the resistance curve, and determines a weld nugget diameter estimate based on both resistance parameters.

Abstract: A welding method and apparatus are disclosed wherein a plurality of stacks of metal sheets are clamped together in sequence at a welding site between a pair of electrode caps across which welding current is supplied to spot weld together the sheets in each of the stacks in a series of welding operations in a production run. The electrode caps are pressed against the sheets in each of the stacks when each of the stacks is at the welding site with an applied force that includes a closing force to clamp the sheets together in a surface-to-surface interface fit plus a predetermined interjoint force that is increased progressively throughout the production run.

Abstract: A method for estimating weld nugget diameter includes receiving current and voltage inputs, a time input, and a force input. In certain embodiments, the method also uses other weld parameters including type of material, type of stack, stack thickness, applied force, preheat current, RMS value of weld current, weld level, and weld time. The method further determines a resistance curve based on the current and voltage inputs, and time input. It also derives parameters from the resistance curve, and determines a weld nugget diameter estimate based on both resistance parameters.

Abstract: A quick change device has a mounting member for mounting an actuator to a resistance welding gun by headed fasteners. The mounting member has several keyhole type apertures arranged in a circle. The fasteners extend through the narrow portions of the keyhole type apertures and the fastener heads clamp the mounting member to the welding gun. To detach the actuator, the mounting member is first released by loosening the fasteners and rotating the mounting member until the heads of the fasteners align with the wide portions of the keyhole type apertures. An additional fastener extends through a round aperture which is removed before the mounting member is released and the actuator is detached.

Abstract: A quick change device has a mounting member for mounting an actuator to a resistance welding gun by headed fasteners. The mounting member has several keyhole type apertures arranged in a circle. The fasteners extend through the narrow portions of the keyhole type apertures and the fastener heads clamp the mounting member to the welding gun. To detach the actuator, the mounting member is first released by loosening the fasteners and rotating the mounting member until the heads of the fasteners align with the wide portions of the keyhole type apertures. An additional fastener extends through a round aperture which is removed before the mounting member is released and the actuator is detached.

Abstract: Mold bushings or nozzles for gas-assisted injection molding processes are disclosed. The devices include movable shut-off mechanisms which selectively facilitate or prevent the passage of molten plastic material into mold cavities. One or more apertures, such as holes, openings, channels, slits, slots, and the like, are provided at or adjacent the end of the pin members or at the end of the devices. The apertures are thin or small and have dimensions which will allow the passage of gas and at the same time prevent the plastic material from plugging or clogging them.

Abstract: Mold bushings or nozzles for gas-assisted injection molding processes are disclosed. The devices include movable shut-off mechanisms which selectively facilitate or prevent the passage of molten plastic material into mold cavities. One or more apertures, such as holes, openings, channels, slits, slots, and the like, are provided at or adjacent the end of the pin members or at the end of the devices. The apertures are thin or small and have dimensions which will allow the passage of gas and at the same time prevent the plastic material from plugging or clogging them.