Device for the automatic demounting of a tire from a rim and machine equipped with such device

A device for the automatic demounting of a tire from a rim having:

• a support arm designed to be mounted on a tire mounting-demounting machine equipped with rotatable rim-carrier means for engaging a rim or a tired wheel and driving it in controlled rotation around a rotation axis, said support arm being liftable and lowerable in a direction substantially parallel to said rotation axis,
• a demounting tool articulated to the support arm and designed to be positioned, in use, on top of or in front of said rotatable rim-carrier means,
• an attachment member for the demounting tool, which has one end thereof articulated to the demounting tool by means of a first articulation pin and the other end thereof pivoted to the support arm around a second articulation pin extending substantially parallel to said first articulation pin,
• comprising
• at least one extension appendage of said support arm or a section of said support arm, which extends beyond said second articulation pin, and
• at least one tie rod member that is articulated on one side to said tool, and on the other side to said extension appendage or section of said support arm.