Abstract: A base assembly for use with a riveting apparatus such as an electromagnetic riveter (EMR). In one aspect of the invention, the base assembly includes a base plate (42) having a raised beveled portion (80) extending upwardly from the upper surface (54) of the base plate (42). A mounting plate (72) fits on and is secured to the base plate (42) by a plurality of coil springs (90-93). The mounting plate (72) has a recessed portion (66) in the lower surface thereof which mates with the raised portion (80) of the base plate (42). Trip switches (104-107) are positioned in the mounting plate (72) for detection of movement of the mounting plate (72) relative to the base plate (42) in response to undesired contact between the EMR and a part assembly or fixture therefor. An output signal indication is provided when one or more of the trip switches (104-107) are actuated.

Abstract: A two axis tracer (10) includes a back plate (34) and a front plate assembly (49) which includes a single sensing member (24) at the top end of which is a mushroom-shaped cap portion (28). Mounted on back plate (34) is a slider assembly (38) which moves in one direction between the front and rear edges of the back plate (34). The front plate assembly (49) is mounted to the slider assembly (38). A first air cylinder (60) operating a lever arm (52) provides movement of the sensing member (24) in the other direction, which is perpendicular to the one direction. A second air cylinder (68) includes an extendable rod, the end of which is secured to the back plate (34), providing movement of the front plate assembly (49) by action of the slider assembly (38). The top and peripheral edge of the cap portion (28) contact surfaces of the part to be worked in the two directions.