Page 31 - Issue 13
P. 31

  full of ideas for a revolutionary device: a uni- versal testing machine.
With the support of his wife, Charlotta, one of the first Scandinavian-American women to earn a degree in medicine, he set about making the drawings for his new machine.
On Feb 6th 1880, Olsen submitted an appli-
 cation to patent a ‘new and useful improve- ment in testing machines.” Patent no. 228,214 was granted on June 1st, 1880.
In those days, most tests of materials required separate machines, each dedicat- ed to a single testing function. Olsen’s Little Giant could accurately perform tensile, transverse and compression tests in one instrument, all housed in a single frame. The device was compact, simple to operate and was not expensive.
When an established Philadelphia firm declined to take on the new product, Olsen’s wife talked him into going into busi- ness for himself. The two had little capital –
only a few thousand dollars – but set up a workshop, Tinius Olsen & Co., at 500N 12th Street in Philadelphia. Soon it was taking business away from his old employers, the Riehlé brothers.
Olsen refused to go into debt, but his wife was determined to see the machine exhibit- ed. She pawned her diamond rings to raise the cash to send the Little Giant to industrial
expositions in Cincinnati and Atlanta in 1881. The machine won gold medals at both shows.
By the next year Olsen had an order for the first 200,000 lbf testing machine ever made and, as an example of his diversity, he also built a machine to test the tensile strength of feathers!
THE LITTLE GIANT – how it broke new ground....
In his patent application, Olsen explained that testing machines pre- viously had difficulty in exerting pres- sure on the sample or wasted most of the applied power in friction.
He proposed to build the weighing levers to be more compact, decrease the power absorbed by friction, provide an automatic motion for the weight on the beam and provide a “sensitive measuring apparatus for measuring the distortion of the speci- men, as well as an apparatus for graphi- cally recording and illustrating the same distortion.”
The Little Giant was a vertical model, with the forces applied to the specimen to be tested coming from above and below. Upper and lower loading crossheads con- tained grips which held the specimen and crushed it, or pulled it apart as the opera- tor turned a handle attached to a system of gears.
This table in turn transmitted the force through levers to a weighing beam, where the load was measured.
His system of screws and gears could apply controlled forces to the test specimen and his weighing levers greatly reduced space requirements.
As an optional attachment, an electric motor could be used to move the weight, or poise, on the beam automatically, with- out the operator being required to touch
it at all.
In addition to greater precision, the Little Giant provided a graphic record of its measurements. Rubber cushions and springs provided damage protection, thus obviating what had been a troublesome problem – testing machines were often damaged when a specimen broke. With all these innovations, Olsen’s device has been called the basis of all testing machines.
 Olsen continued to make innovations in the testing machine field and in 1891
won the Elliot Cresson Gold Medal for his autographic testing machine, which gen- erated a permanent, easily interpreted record of stress-strain results. Other hon- ours followed, including a medal from the King of Norway.
Olsen retired in 1929, aged 84, and died in 1933. The company is still run by his descendants, now in its fifth generation.
What started out as a small business in Philadelphia now has offices and manu- facturing plants worldwide,
including the UK, India and,
most recently, China.
With an automation interface, InfiniteFocusSL is also applied for fully auto- matic measurement in production.
All products work on the well established FocusVariation principle providing dense point based data in addition to full colour images.
This data can be compared against CAD data to verify production methods and also used to effectively measure wear or varia- tion from standard.

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