639.60  Intervention — petition.
  Any person other than the defendant may, before the sale of any attached property, or before the payment to the plaintiff of the proceeds thereof, or any attached debt, present a petition verified by oath to the court, disputing the validity of the attachment, or stating a claim to the property or money, or to an interest in or lien on it, under any other attachment or otherwise, and setting forth the facts upon which the claim is founded.
[R60, §3237; C73, §3016; C97, §3928; C24, 27, 31, 35, 39, §12136; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §639.60]
Intervention generally, 
R.C.P. 1.407