John Bee and Richard Brazier carried Laura Smith out of her bedroom after her family home in Severn Street, Shrewsbury, caught alight.

Mr Brazier said it was the most dramatic rescue of his 18-year firefighting career.

Ms Smith was treated for smoke inhalation but was otherwise unhurt in July’s incident.

Choking black smoke

Fire crews called to Ms Smith’s home during the early hours of 9 July said the living room and kitchen were well alight when they arrived with flames also engulfing staircase spindles and a banister.

There was choking black smoke throughout the house, they said.

The two firefighters put out the flames in the living room while heading for the burning staircase which they put out as they went upstairs.

Ms Smith was carried out of her bedroom by one firefighter as the other protected them with the hose as some flames had reignited.

The firefighters then went back into the house for her brother, Sam, but he escaped the fire by jumping from a window.

The main spindles of high-speed machining centers and combined machine tools typically use duplex angular ball bearings in the front and either duplex angular ball bearings or cylindrical roller bearings in the rear. In the rear position, the high-speed performance of angular contact ball bearings is better than cylindrical roller bearings.

However, the main spindle structure is complex because the ball bushing or preload spring has to absorb thermal expansion of the shaft. On the other hand, when a cylindrical roller bearing is used, a structure absorbing thermal shaft expansion is unnecessary as the bearing itself can move axially but the high speed performance is inferior to the angular ball bearing.

Aiming to increase the speed rating of the cylindrical roller bearing while simplifying the main spindle structure, the company focused on the heat generation of the bearing, and developed an NU-type cylindrical roller bearing that allows speeds up to 3.25 million dmn.

Medical firm reports cycle time savings of nearly 30% after installing new mill-turn centre.

Owned by Hitachi, Air Bearings Ltd of Poole is a world leader in ultra-high-speed drill spindles for manufacturing printed circuit boards (PCBs). Air Bearings’ products are a key element of the world’s most popular PCB drilling machines from Hitachi Via Mechanics – which drill connection vias and holes at speeds of over 10 holes/second.

Advances in PCB drill spindle motors almost invariably rely on increasing rotational speed, to improve drilling productivity and quality. Up until 2010, the Air Bearings Ltd (ABL) design team generated new motor designs using principles and know-how of air-bearing-equipped motors that had been acquired and proven over decades of business. The development process usually involved making a number of prototypes, and the team typically delivered a couple of new motor designs every year.

However, as spindle speeds increase – which over the last decade have escalated from around 80,000 to 350,000 RPM – the design challenge has become tremendous. Increasing rotational speed depends largely on reducing rotor mass. To achieve this, Air Bearings has started to extend the motor technologies it employs to improve efficiencies – from AC induction motors to permanent magnet types – and to explore the value of being able to optimise a much wider range of design parameters.

CAE tool support is viewed as essential for this more complex design environment, and ABL compared several electromagnetic simulation software packages including Opera from Cobham Technical Services – Vector Fields Software. Given the company’s focus on pushing motor performance to its absolute limits, the fidelity of the simulation process was essential, and ABL took the unusual step of comparing software design packages by correlating their predicted results against the known performance of existing motors.

“We looked at four packages. Only two of them gave us the very high simulation accuracy we needed, and of these, we chose Opera because it offered the most modelling flexibility,” says Neil Russell, ABL’s R&D Manager. “The design automation now gives us great confidence that we can improve design throughput substantially, by between five- and ten-fold, with the same headcount.”

Rotary coupling system allows use of Micro Line high-speed spindles in turret style machines. Providing support for all electrical and pneumatic requirements for high-speed spindles, models are rated to IP67 and support either 2 or 4 spindles. Use of positive air over-pressure prevents coolant/chip contamination, and pneumatic supply within coupling provides air-seal to spindles. Mounted to CNC lathe turret face, couplings are able to rotate up to 500 rpm.