7 minute read
Feel the Torque
From humble beginnings 80 years ago, in a small workshop, to the latest purpose-built factory, Norbar has pioneered many of today’s solutions for torque control
Incorporated in 1943, the ‘North Bar Tool Company’ became the first company in Britain to commercially manufacture torque wrenches. The initial demand was driven by the need for the gasket-less cylinder head of the Rolls Royce Merlin engine to be accurately tightened. Bill Brodey and his partner Ernest Thornitt obtained a licence from Britain's wartime Government to begin the manufacture of torque wrenches and Norbar was born.
Norbar specialises in the manufacture and worldwide distribution of torque tools for torque tightening, measurement and calibration, as they are engaged solely in the design, development and production or torque tightening and measuring equipment. Their main customers include manufacturers, and engineering services who operate within a wide range of industries including transportation and rail industry.
Transport
Norbar’s involvement in the transport industry begins with the manufacturers, and extends through the life of vehicles and rolling stock. It also plays a key role in the infrastructure element of transport, building and maintaining road and rail networks.
The company provides the industry with ergonomic tools including; torque wrenches that are easy to read and adjust, power tools that emit low levels of noise and vibration, and torque measurement instruments.
Torque wrenches
Norbar has worked to manufacture a torque wrench that addresses the market needs, and is both fast and light to adjust with the clearest possible scale. Another version of the industrial wrench that has found great success in the rail track maintenance industry is the 1 11/16” bi-square wrench. It was produced at the request of the rail industry for torque tightening rail fishplate bolts. It eliminates the possibility of sockets or square drives being left on the railway track by integrating the 1 11/16” socket permanently onto the end of the wrench.
Powered torque tools
EvoTorque® are electronic torque tools designed for applying torque to threaded fasteners. The unique ‘Intelligent Joint Sensing’ technology will accurately tighten to the correct torque without the risk of excess overshoot or undershoot that is common in other electric tools. EvoTorque® tools give continuous (non-impacting) rotation and are quiet in use. EvoTorque® tools utilise patented technology to give unprecedented joint control from hard through to soft joints. They are available in both mains-electric and battery-powered ranges. The battery tool version EvoTorque® Battery Tool (EBT) shown on the previous page is a transducer controlled battery powered torque tool that is designed for accurately applying torque to threaded fasteners with data memory and data transfer capabilities.
Pneumatic torque tools are handheld, air driven, non-impacting torque delivery tools intended to tighten and loosen nuts, bolts and threaded fasteners. However they do come with various health and safety risks as they involve the operator being subjected to high levels of noise and vibration, but Norbar’s PneuTorque® is a rotating pneumatic torque wrench that features almost no vibration and low levels of noise. PneuTorques have been used on many transport infrastructure projects including bridge and tunnel construction.
Measurement and calibration
The importance of keeping torque tools in peak calibration condition is well established. The main reasons that more companies do not perform calibration checks on their own wrenches are the cost of testers and fears over the complexity of the testing equipment. Norbar’s TruCheckTM torque wrench testers are cost effective being significantly cheaper than most similar products on the market and simpler to use. TruCheckTM was designed specifically with the needs of automotive and transport workshops in mind.
The importance of torque control
Torque is defined as any force or system of forces that tends to cause rotation about an axis. In order to control this many methods exist to join the two or more parts together, and typically the threaded fastener is what is used to streamline this process.
The threaded fastener clamps parts together with a tension that exceeds the external forces leading them to separate. It is vital that the initial tension is correct, as if its too low varying loads act on the bolt and it will quickly fail, and if initial tension is too high the tightening process may cause bolt failure. Finding the correct balance is done by specifying and controlling the tightening toque.
Engineer to order service
Whilst Norbar produces an extensive range of standard equipment, there are times when something outside the standard range is required, and Norbar’s engineer to order service can be beneficial.
As an ISO 9001 company, Norbar both designs and manufactures special equipment to meet customer specifications. These projects range from modified torque wrench end fittings to complete torque and angle control of multi-spindle nut runners.
Relevant European Safety Directives are applied where appropriate, giving further assurance that the engineer to order equipment is of the highest standard.
Case study: London Underground
Norbar Torque Tools’ Specialist Engineering Department has developed a unique torque tool for London Underground. The new tool has been developed to solve a specific engineering challenge, namely the removal and refit of the inter-car coupler mounting bolts on the fleet of 47 Bombardier 09 Stock trains used on the Victoria Line in London and maintained at the Northumberland Park depot.
The inter-car coupler mounting bolts are accessed from the underside of the train, either from the pit road or with the train jacked up. The coupler mounting has four bolts with a significant boss in the middle that houses the Absolute Position Reader (APR). Of the four bolts, the upper two were particularly difficult to access due to them being deeper up into the train and surrounded by other hardware. The bolts are required to be tightened to a torque of 1,050 N·m.
London Underground’s tool supplier, Hayley Group, contacted Norbar with the remit of providing one tool to reach all of the bolts on the coupler.
The Norbar solution was to use a PneuTorque® PTS tool with a specially developed drive that is slim, long and offset from the PTS square drive, with a series of gears arranged in line and driving each other. This enables all of the bolts on the Bombardier 09 Stock trains to be reached during maintenance.
In addition, the gearbox of the tool is supplied with quick change reaction arms in order to reach all of the bolts and safely take torque reaction from the tool. The aluminium bodied gearbox can also be positioned on the bolt before the driving tool is coupled. This significantly reduces the total weight that has to be lifted and makes the location of the offset gearbox and its reaction plate much easier.
Norbar’s website features a toque tension calculator, to use the calculator visit: https:// www.norbar.com/Support/Calculators/TorqueTension-Calculator
For more information and to view an example list of projects previously delivered by Norbar visit: https://www.norbar.com/ Support/Services/Engineer-to-Order
Tel: 01295 270333
Email: enquiry@norbar.com
Visit: www.norbar.com
Address: NORBAR TORQUE TOOLS LTD. Wildmere Road Banbury, Oxfordshire OX16 3JU United Kingdom
‘My colleagues and I were very impressed by your entire manufacturing operation, and it was evident from the tour the standards you achieve are impeccable. It's comforting to know we're in good hands, and we proudly promote the use of your equipment internally.’
Michael Millard, National Repair Improvement Manager for The Automobile Association
