Louis Masson

A power producer sought judicial intervention to force renegotiation of a long-term fixed-price electricity contract after market changes generated large resale profits for the purchaser.

The Court held Quebec civil law did not provide a basis to imply a duty to renegotiate, to apply unforeseeability in these circumstances, or to redistribute contractual benefits through good faith or equity.

The agreement allocated price fluctuation risk and remained enforceable as written.

The appeal was dismissed, with a dissent that would have recognized a relational-contract duty to cooperate.

The appellant owned patents for an electro-magnetotherapy device that used 'circuit means' to control electromagnetic waves.

The respondents developed a competing device that achieved similar therapeutic results but used a 'microcontroller' instead of circuit means.

The appellant sued for patent infringement, arguing the respondents took the substance of the invention.

The Supreme Court of Canada held that patent claims must be interpreted using purposive construction, balancing fairness to the patentee with predictability for the public.

The Court found that the use of 'circuit means' was an essential element of the patent claims, and the respondents' substitution of a microcontroller was a fundamentally different technology.

Therefore, the respondents' device did not infringe the patents.