Long-life Bolt from Svenska

Targeted at the retrofit sector as well as the end user in the quarrying sector, the Expander Bolt, manufactured by Swedish company Svenska Expander AB, is claimed to be a long-term solution to worn pivot pins.

Although each unit is essentially twice the price of conventional pins, boss Richard Svensson said: 'The ability to fit the bolt on site in less than 15 minutes cuts costly downtime.'

Traditionally, when excessive wear reaches a point where the pivot pin has to be repaired, the complete machine is brought into the workshop.

Standard pivot pins, unlike Expander Bolt, require clearance to allow them to be inserted and removed. It is this 'tolerance' which is the prime cause of pivot wear. As the joint moves back and forth, wear is created in both in the mounting brackets, and the arm. Stress loads increase the speed at which wear takes place in all parts of the pivot.

Forming a tight fit, which takes up any slack in the pivot pin, Expander Bolt, according to its manufacturers, does not require adjustment, will never require replacement and is likely to outlast the life of the machine.

The basic operation involves the removal of the old pivot pin and insertion of the bolt. Setscrews are then tightened, through the pressure plate and a tapered sleeve, into each end of the bolt.

The pressure plates are then forced onto the tapered sleeve which in turn expand over the tapered end of the shaft of the bolt.

Suitable for a wide range of plant including ADTs, telehandlers and crawler dozers, the bolt can be removed on site by a service engineer using a torque spanner and normal service tools.

Although the bolt is already being supplied to OEMs, Expander UK, a new company formed in October by director Stan Salisbury, is set to target end users. By the close of 1995, the company expects to have established eight UK distributors.

The bolt, which has been available in Sweden for the last eight years, is seen by some OEMs as a retrograde step as it threatens sales of spare parts. However after 50,000 hours of testing, VME has adopted the bolt as an original spare part for all of its Volvo BM machines.

The bolt was first tested on a Volvo BM846 which outlasted three machines, running 24 hours a day. It is now being used on a fourth machine.

Svenska Expander AB was established in 1986 by company president Roger Svensson, whose father Everth Svensson invented the Expander Bolt based on his 40 years' experience in plant hire business.

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