MyPatent.co.za

(Extract from MyPatent’s Patent e-Book)

Fuses or shock tubes were introduced to the mining, quarrying and construction industries in the early 1970’s as a method of initiating explosions. These tubes had a fine layer of explosive dust on their inner walls. The detonator at one end of the tubes initiated an explosive wave along the tube to detonate a charge at the other end. However, this explosive coating would dislodge from the inner wall during transportation and installation, resulting in misfires.

To make the tube more resistant to impact Ensign Bickford added an abrasive resistant outer tube over the inner tube. During handling, this outer tube absorbed most of the impact that would have otherwise dislodged the explosive dust.

Ensign Bickford obtained a patent for this invention, which was subsequently challenged on the ground of obviousness. The court found that merely adding a resident coating to an impact sensitive article would have been obvious to an expert in the field, and revoked the patent due to the absence of an inventive step.

To the best of our knowledge, this is the first of only three patents that has ever been revoked on the ground of lack of inventiveness in South Africa.

Suggestion: provided you invention is novel, despite misgivings as to inventiveness, file a patent.