It’s an invention that has changed the way tube is bent by precision industries around the globe.
Convinced there was a better, more precise way of bending tube than by using the hydraulically operated machines of the day, in the late 1980s Unison’s founder, Terry Pickering, along with his son, Alan (who is now the company’s joint managing director), set about reinventing the process of tube manipulation.
“It was no great secret that the accuracy of hydraulic tube bending machines could be affected by changing oil temperature,” says Alan Pickering. “In other words, a machine with cold hydraulic oil at the start of a shift might well perform differently later in the day when its oil was hot. The greater viscosity of the cold oil, compared to that of hot oil, would typically result in the machine operator having to make temperature-related adjustments during the day to ensure satisfactory levels of repeatability. With all those manual adjustments to make – particularly on the clamp and pressure die – each operator would keep a black book of how they managed to get a good part out of their tube bending machines.”
Taking the black art out of tube bending
Unison’s ultimate goal was to take the black art out of tube bending as much as possible, by letting a CNC capture all the correct machine axis settings – in order to repeat them on future bends and get to a point where ‘right first time’ results were possible.
During the R&D process, it also became clear that to achieve this, it was important to not only control axis position, but also the force of each axis.
Following a 1991 Brite Euram feasibility study into automatic setup tube bending, in 1992 Unison secured a SMART award to develop three all-electric tube bending machines.
“At that point we were already well on the way to understanding what we would need to do to create the world’s first-ever all-electric tube bender,” adds Alan Pickering."The easy axis to do was the bend arm; the challenge was all the other axes. It took a few years to achieve what we wanted, but by pushing the servo actuators of the day to their limits, we developed a process where low-friction-slide adjusting mechanisms powered by an electric motor with torque control, brought absolute pressure control to bending machine components such as the clamping die, pressure die, mandrel and powered follower. All-electric tube manipulation had been invented – with the assurance of accuracy and repeatability at the tightest of bending parameters for large and small production runs, and with no concern over hydraulic oil or even external temperatures.”
The birth of the Breeze
Called the Unison Breeze, due to the speed and ease it brought to achieving repeatable tube manipulation, the world’s first all-electric three-axis tube bending machine was launched by Unison in 1994.
UK and German patents were registered, and right-first-time tube bending was born.
Over the following years, Unison developed and launched the world’s first all-electric five-stack tube bending machine, followed by the world’s first 76 mm, 115 mm, 150 mm and 180 mm multi-stack machines, as well as robotised benders and twin-head tube benders for producing symmetrical, simultaneous bends.
Today, with facilities in the UK and USA, Unison offers the world’s largest range of ultra-precise, all-electric tube and pipe bending machines for diameters ranging from 4 mm to 275 mm, in single-stack, multi-stack and right/left versions.
For more straightforward, repetitive applications, it has also recently introduced a range of high-accuracy hybrid machines.
“All-electric tube bending was a difficult sell for us at first,” says Alan Pickering. “In fact it took a number of forward-thinking customers to put their faith in our technology before others would make the switch. However, our big breakthrough came when Airbus ordered their first all-electric tube bender from us – a machine that paid for itself in 16 weeks, in reduced scrap alone. As all-electric tube manipulation caught on, competition from the bigger players was inevitable, but we kept our heads down and kept on pushing forward. Today, of course, all-electric tube bending machines are commonplace offerings from manufacturers from around the world. But I am proud to say that we remain the preferred choice of countless organisations from all manner of industry sectors. Whether it’s aerospace, performance automotive, marine, oil & gas, energy or general manufacturing, we take pride in building powerful, highly energy efficient machines that meet the challenges faced by our customers head on. Thanks to our build quality, uncompromising customer support and user-friendly control systems – not to mention our tube bending simulation software and innovative tube bending application app – I truly believe that 30 years on from the first Unison Breeze machine, we still have, and always will have, the edge."
