This section is from the book "Popular Law Library Vol7 Equity Jurisprudence, Trusts, Equity Pleading", by Albert H. Putney. Also available from Amazon: Popular Law-Dictionary.
A common class of injunctions are those for the protection of patents and copyrights.
"When the existence of a patent right or of a copyright is conceded, or has been established by an action at law, the jurisdiction of equity to restrain an infringement is too well settled and familiar to require the citation of authorities in its support. From the nature of the right and of the wrong - the violation being a continuous act - the legal remedy is necessarily inadequate. The ordinary form of relief is an accounting of profits and an injunction in equity; indeed, the action at law is seldom resorted to, except for the purpose of establishing the validity of the patent or copyright by the verdict of a jury when it is really contested. Under the Constitution of the United States, the cognizance of suits for the infringement of these rights belongs exclusively to the Federal courts." 19
A temporary injunction will only issue in patent cases where the rights of the patentee are clear.20 There must have been either an adjudication of the rights of the patentee, or a long continued public acquiescence in such rights.21