Hartmann, J., "Development of the Handheld Low Voltage Electromagnetic Riveter," SAE Technical Paper 902048, 1990, doi:10.4271/902048.
The Handheld Low Voltage Electromagnetic Riveter(HHER) has been under development for the past three years. The HHER is an impulse device deriving its power from the discharge of a bank of capacitors through a pancake coil. This gives the HHER the advantage of an accurate and repeatable output force, which results in exceptional consistency in rivet upset dimensions. The rivet/hole interferences obtainable with the HHER have been shown in many cases to be superior to traditional rivet driving techniques, resulting in riveted joints that exhibit excellent fatigue life.(5)Typically, two opposing guns are used on either side of the rivet. These are synchronized through a control cable of arbitrary length. This feature allows accurate installation of slug rivets by hand, a function that in many cases is not possible with existing handheld tools. For the case of headed rivets, the force balancing bias feature eliminates of the cosmetically undesirable “salt and pepper” marks which are characteristic of pneumatic riveters.In addition to improved rivet quality for the manufacturer, the HHER systems offer the operator advantages as well. The HHER is extremely quiet operating many decibels (typically under 90 dB peak) below that of pneumatic rivet guns. In many cases no ear protection is necessary. The one shot formation results in a decrease in formation time for tough fasteners such as A286 and large diameter solid aluminum rivets, reducing worker fatigue.Electroimpact has worked closely with many aerospace companies in the advancement of the HHER designs. This work has resulted in four different models with increasing capacity. Two models are currently being used in production at two aerospace companies.