Patent ID: 6862790
Filing Date: 2005-03-08
Classification: B21D,B21J,Y10T

Abstract:
1. A dimpling device for dimpling surrounding areas of rivet holes preformed in superimposed first and second workpieces into dish shapes in order to fasten the superimposed workpieces by a flush rivet, the dimpling device comprising: a center pin capable of being inserted into the rivet holes of the workpieces and having a tip end; a punch slidably fitted around an outer periphery of the center pin and capable of making contact with a working surface of the first workpiece; a first workpiece holder slidably and detachably fitted around an outer periphery of the punch and having a holding surface capable of making contact with the working surface of the first workpiece without an appreciable gap therebetween; a second workpiece holder detachably engaged with the tip end of the center pin and having a holding surface capable of making contact with a working surface of the second workpiece without any appreciable gap therebetween; a die integrally formed with the second workpiece holder and cooperatively engaging said punch during a dimpling operation; means for driving said workpiece holders for making the first workpiece holder and the second workpiece holder approach each other along an axial direction of the center pin, wherein the working surfaces of said first and second workpieces are held therebetween; and means for driving said center pin for moving the center pin in the axial direction so as to dimple the surrounding areas of the rivet holes with the punch and the die into dish shapes.