A Practice Note addressing the process of applying for preliminary injunctive relief in the Court of Common Pleas of Allegheny County, Pennsylvania. A checklist of practical steps for obtaining a preliminary injunction in the Court of Common Pleas of Allegheny County, Pennsylvania.The court looked to the guidance in eBay that any injunctive relief should be consistent with the "traditional principles of equity. In many patent suits, patent holders seek injunctive relief to prevent an accused infringer from continuingto practice the patented invention. Henry Sneath is a corporate and commercial trial attorney, mediator, arbitrator and Federal Court Approved Mediation Neutral and Special Master. PAT may well exercise its prerogative to not seek injunctive relief in the courts. This article focuses primarily on recent changes to irreparable harm standards, how those changes have altered the patent litigation landscape. Preliminary Injunction. Pennsylvania Western District a forum of choice for patent infringement and invalidation actions. Pennsylvania Western District a forum of choice for patent infringement and invalidation actions.