Abstract: A method and apparatus for forming pierce type or pierceless clinch joints in two sheets of material, such as sheet metal, employs a drive system which eliminates the need for camming mechanisms and periodic adjustment of worn cams. A die and anvil are relatively moveable and are displaced relative to a punch by means of a single drive lever which is driven by the output shaft of a hydraulic or pneumatic cylinder. A slide which drives the die is pivotally connected both to the drive lever and to a second slide which drives the anvil. The anvil slide is pivotally connected to the drive lever. The anvil and die are displaced in synchronism with each other and with the punch to form a clinch joint in a single workstroke of the cylinder motor.

Abstract: A method and apparatus for forming pierce type or pierceless clinch joints in two sheets of material, such as sheet metal, employs a drive system which eliminates the need for camming mechanisms and periodic adjustment of worn cams. A die and anvil are relatively moveable and are displaced relative to a punch by means of a single drive lever which is driven by the output shaft of a hydraulic or pneumatic cylinder. A slide which drives the die is pivotally connected both to the drive lever and to a second slide which drives the anvil. The anvil slide is pivotally connected to the drive lever. The anvil and die are displaced in synchronism with each other and with the punch to form a clinch joint in a single workstroke of the cylinder motor.

Abstract: A resistance-type welder employing a three phase, pulsed power supply and a pair of opposed electrodes which a workpiece may be clamped under pressure, includes a microcomputer based control system for allowing precise selection and control of welding sequences such as the duration during which the workpiece is clamped, the duration during which current is supplied to the electrodes and the duration during which the workpiece remains clamped between the electrodes after current flow is terminated. A plurality of switchable input devices allows data corresponding to a plurality of process variables to be input to a random access memory. A central processor enabled by a manually operable control switch produces control signals for operating a control and firing circuit in accordance with programmed instructions and the data stored in the random access memory in order to control each step in a welding cycle for precise time periods.

Abstract: An improved die assembly for use with a punch is employed to produce stitch connections between sheets of rigid, deformable material. The die assembly includes an anvil body having a central anvil portion and a pair of arcuate depressions respectively on opposite sides of the central anvil. A pair of die portions are pivotally mounted on opposite sides of the anvil and include curved sections which are conjugally received within the depressions of the anvil body and function to transmit force applied by the punch through the curved sections to the anvil body, thereby relieving the pivotal connections from undue stress. The die portions and the anvil body are provided with opposing surfaces between which there are trapped coil springs for urging the die portions toward each other. In an alternate embodiment, biasing of the die portions toward each other is achieved by surrounding the die portions with a layer of molded, resilient material such as urethane.

Abstract: A power supply for a pulse type electrical resistance welder includes an A.C. source of electrical power, a firing circuit for delivering spikes of current to a pair of welding electrodes and a precharging circuit for precharging the firing circuit with a quantity of electrical energy sufficient to produce satisfactory welds in the first cycle or first few cycles of power. The precharging circuit is controlled by control circuit which includes a thumb wheel switch for presetting the voltage to which the firing circuit is to be precharged. A relay circuit automatically disconnects the precharging circuit from the firing circuit before the latter discharges its energy to the welding electrodes. A safety circuit is provided for automatically discharging the firing circuit in the event of a power failure.

Abstract: A resistance-type welder employing a pulsed power supply and a pair of opposed electrodes between which a workpiece may be clamped under pressure, includes a microcomputer based control system for allowing precise selection and control of welding sequences such as the duration during which the workpiece is clamped, the duration during which current is supplied to the electrodes and the duration during which the workpiece remains clamped between the electrodes after current flow is terminated. A plurality of switchable input devices allows data corresponding to a plurality of process variables to be input to a random access memory. A central processor enabled by a manually operable control switch produces control signals for operating a control and firing circuit in accordance with programmed instructions and the data stored in the random access memory in order to control each step in a welding cycle for precise time periods.