A short history of the bending machine – Part 2
From mechanical sheet metal processing in the 18th century to the fully automated double bending machine of the digital age. The history of the bending machine continues.
Rolling mill for mechanical plate production | © Morphart – stock.adobe.com
Manually operated brake, end of the 19th century | Illustration from: Otto Lueger, Lexikon der gesamten Technik, 1904
69-MH-4/1 series manual bending machine with machine frame, one of the first machines from Jorns, around 1973 | © Jorns AG
82-NC series hydraulic bending machine, 4 m long, one of the first NC-controlled bending machines from Jorns, around 1985 | © Jorns AG
Fully automated Jorns double bending machine JDB, 12.2 m long, bending capacity 3 mm steel sheet, 2021 | © Jorns AG
The Industrial Revolution: mechanical metalworking in grand style
One thing had not changed in metalworking by the middle of the 18th century: it was still very hard manual labour. But come the Industrial Revolution, more and more threaded rods made of wood and wooden beams were replaced by metal parts; the closing function also consisted of levers, control shafts and eccentric bearings of metal. The wooden bending table was often reinforced with metal, the so-called edge rail, to achieve exact bending results. And mechanical sheet metal production really took off at the end of the 18th century when the English industrialist John Wilkinson invented the reversing rolling mill.
Middle of the 19th century: the first “sheet metal bending brakes” are built
Metal sheets were now available in abundance and consequently their processing was also quickly mechanised. The first bending machines were called “sheet metal bending brakes” or “folding benches” around 1875. They were real heavyweights, but they certainly made work easier. Hydraulics then came onto the scene: the locking lever and bending tools were powered by one or several hydraulic cylinders and controlled with a simple lever valve. The shears were initially only moved manually by pure momentum, but later on these were also powered hydraulically. For a long time, the position of the bend was defined with a folding rule or template. These were joined by the first adjustable, manually-powered back stop systems later on.
Bending systems became increasingly electrified between the beginning and middle of the 20th century. The first simple control systems were developed to control the clamping, bending and cutting functions. From then on, bending machines almost controlled themselves.
1973: the Swiss firm of Jorns starts producing bending machines
When the master mechanic Kurt Jorns took over the firm of Konrad in Lotzwil, Switzerland, the individual stands of the bending machines were still bolted to the ground on the customers’ premises. This proved a challenge in terms of the statics depending on the substrate, and one that could result in inaccuracies during bending. Kurt Jorns recognised this problem and developed one of the first machine frames for the bending machine – a novelty in the industry. In 1975, Jorns were able to present the first NC-controlled bending machines: the 78 and 77 series. Not long after, these were followed by the first bending machines with a motorised back stop and electric shears.
The history of the bending machine in the digital age
The digital age began with numerical controls (NC) for all machine tools. These were joined by thumb wheel switches for bending machines in the 1980s. Thanks to these, exact values could be pre-set and run for the clamping, bending, cutting and back stop systems. A program was limited by the number of rows of thumb wheel switches.
The first bending machines with CNC and monitor control systems were built at the beginning of the 1990s. Measuring systems also became more and more precise and speeds higher. The first tapered back stop systems came onto the market. These were joined at the end of the 1990s by graphic control systems, followed by touch screens that could be operated directly with a finger. Fully-automated, double bending machines celebrated their première at the turn of the millennium.
And where are bending machines heading in the future?
“The bending machine has a long history. and it will remain relevant for mankind in future too, because nowhere near everyone on the planet has a roof over their heads,” says Marc Jorns, metal bending expert and CEO of Jorns AG. And how will things develop technically? “Bending machines will become even more precise and faster in future. The bending process will be further automated and what’s more, it will be interconnected even better with higher-order software components. Preventive maintenance will also make things a lot easier, especially in larger production facilities that work in multiple shifts. Smaller companies will also profit from these developments.”
So you see, the history of bending machines, which began thousands of years ago with sheet metal processing, continues. Because bending machines are urgently needed to make roof and wall sections for protected rooms – now and in future.
Have you anything to say about the history of bending machines? Let us know.
Sources
Gerd Ising, Die Schwenkbiegemaschine, Books on Demand GmbH, Norderstedt 2005
Otto Lueger, Lexikon der gesamten Technik und ihrer Hilfswissenschaften, DVA, Stuttgart, 1904
Wikipedia, Biegemaschine, https://de.wikipedia.org/wiki/... und Schwenkbiegen, https://de.wikipedia.org/wiki/...
