Protection against electrical surges
By interrupting the current in the event of a short-circuit or overload, they prevent potential fire hazards: Circuit breakers. These safety devices, which were first manufactured in 1924 by Hugo Stotz in Mannheim, are now established components in all electrical installations, where they ensure the safety of all the circuits present, irrespective of the different current intensities and cut-off characteristics. In an emergency, the current is cut off by means of a bimetal strip which bends as it is heated by the current passing through it and trips the cut-off mechanism or, alternatively, by an inductive electromagnetic effect that is triggered in response to a short-circuit.
At the same time, circuit breakers can also be activated manually using the actuator lever, for example when performing maintenance work or for the temporary disconnection of an electric circuit. All in all, circuit breakers are highly complex components that have to operate absolutely securely and reliably. This precision and reproducibility can be guaranteed using Bihler technology because the majority of the required components (magnetic assembly, trip mechanism, thermal assembly, arc extinguisher and terminal) can be manufactured flawlessly and in top quality on Bihler’s systems.
Safe mains supply
NEMA sockets (USA)
NEMA sockets are a common type of mains power receptacle used in the United States, Canada and parts of Asia. NEMA receptacles are designed for voltages of 125-600 volts and currents of 15-50 amps. It goes without saying that safe and simple use is the number-one priority. A key part in these receptacles is the connecting piece that carries the mains current to an attached electrical appliance or other load.
In the USA, this connecting piece is made on a GRM 80 mechanical stamping and forming machine and a BZ processing center. Together, they carry out all the necessary steps, from punching and bending to thread cutting, screw insertion and assembly. These two Bihler systems, working in three lines, produce roughly 300 of these receptacle parts. There are around 80 variants of the final product. The Bihler machines, running 24/7, excel in terms of their reliability. They also operate as smart network, which allows them to buffer production – a valuable capability.
Grounding contact, grounding connectors
Grounding and the dissipation of electric currents play an important role in the electrical engineering field. They ensure that no contact voltages arise in the systems and equipment, that parasitic currents are dissipated and that disruptive electrical couplings are avoided. Grounding is usually performed by means of a permanent screw connection. Recently, however, a plug-in solution has also become available. The heart of such grounding connectors is the grounding contact with ground pin and ground spring as shown here. These can be manufactured in large volumes using Bihler technology – for example on a GRM 80P stamping and forming machine which provides throughput of 100 parts per minute.
The system, which provides an extra-large machining space for the mass production of larger precision stamped and bended parts and assemblies, starts the process by drawing in the strip from the coil. The strip is then cut and the collar drawn. Thread cutting is performed next with the two outer M3 threads and the central M4 thread. The threads are then centerpunched and the entire part is bended, cut and ejected onto the conveyor for OK parts. In addition to the high output volumes, the solution also excels through its particularly short setup times.