Why do Giles and Francis interrupt the court in "The Crucible"?

Giles Corey, Francis Nurse try to present a petition to the judge testifying to the innocence and pious character of Martha Corey (wife of Giles), and Rebecca Nurse (wife of Francis).  John Proctor also, in Act 3. sc. 1, is trying to get his wife, Elizabeth, acquitted of all charges.  They are not successful because their action is seen as an attempt to overthrow the court.  After the rebellion in Andover, Judge Hawthorne and Danforth are wary and tell them that they need to produce the signers of the petition.  Ultimately, they are unsuccessful in their attempt to save Martha Corey and Rebecca Nurse.