07 Sep Rucker Co v Gavel’s Vulcanizing Ltd (1985), 7 CPR (3d) 294 (FCTD)
The reproduction of one element of a patented product does not typically amount to infringement of the patent. However, if it is plain that a given patent was drafted to protect a single novel element of an otherwise familiar product, a court may read it as such and find the reproduction of that element to constitute an infringement of the patent.
While third parties may repair patented products, they may not substantially reproduce such products without permission from their makers.
Your company sells a widget. The widget is largely commonplace, save for one feature: a special doodad of your design. The widget is patented. Although the lawyer who drafted the patent took care to emphasize the doodad in the patent, the document is ambiguous in its wording: it may be read to protect the widget as a whole, rather than the doodad in particular.
The doodads in your widgets wear out faster than the the widgets themselves. In fact, over time they substantially dissolve with use. A local machinist has made a business out of repairing the doodads from your widgets. Customers approach him with doodad fragments and, using those fragments alongside quantities of new material, the machinist produces replacement doodads identical to those in your widgets. Suspecting that the machinist’s operation infringes your patent, you request that he stop.
Your suspicion is well founded. Although the patent protecting the doodad in your widget is ambiguous in its wording, a court would likely recognize that the patent is intended to protect the novel feature. Accordingly, a court would likely interpret it to protect the feature. Although the machinist is free to repair damaged doodads, his operations go beyond repair. They amount to unauthorized manufacturing.