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: 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.