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.
An interlocutory or preliminary injunction is one issued during the pendency of the suit, prior to the final hearing. Such an injunction continues in force until the final hearing of the case, unless sooner rescinded by a subsequent order of the court. The object of interlocutory injunctions is to keep things in statu quo, not to determine the right itself.3
1 Jeremy, Eq. Ju., 307. Quoted in Parsons vs. Marye, 23 Fed. Rep., 113, and followed in 22 Cyc, 740.
2 Rogers Locomotive, etc., Works vs. Erie R. Co., 20 N. J. Eq. 379.
When there is necessity for prompt action an interlocutory injunction may be issued without notice to the defendant. Such an injunction is called an ex parte injunction. As soon as he has notice of its issuance the defendant may come in and move to dissolve such injunction. In the Federal courts no ex parte injunctions are issued, but the same results are obtained by what are known as restraining orders.
3 22 Cyc, 740; Butler vs. Useful Manufactures Co., 7 Ohio Dec, 249; Harriman vs. Northern Securities Go., 132 Fed., 464.