Masimo Unit Says Its ‘Launch’ of Apple Watch Rival Wasn’t a Sale

A manufacturer Masimo Corp. acquired last year in a billion-dollar deal urged a federal judge to dismiss Apple Inc.’s patent-infringement claims against it, arguing Apple hasn’t shown Sound United sold the health-tracking watch the tech giant alleges Masimo developed by “secretly copying” the Apple Watch.

“Apple did not plausibly allege that Sound United ever sold the W1 in the United States,” Sound United LLC said in reply briefs supporting its motions to dismiss two suits Apple filed in October over the rival device, called the W1.

Cupertino, Calif.-based Apple said in its complaints that Masimo “hastily developed” its W1 watch …