ApplicationNo. 559539 filed on 03/18/1975
US Classes:299/31, Stepper-type advance-causing means299/33, With mine roof-supporting means405/141Shield
ExaminersPrimary: Purser, Ernest R.
Assistant: Pate, III, William F.
Attorney, Agent or Firm
International ClassE21D 9/10 (20060101)
Foreign Application Priority Data1974-03-18 JA
AbstractTunnel excavator for forming an upper half annular hollow space in the solid earth. The excavator has an arch shaped shield provided with a plurality of chambers in which excavating machines are located. Each of the excavating machines is swingably supported in the respective chamber and gripper means for securely abutting against the outer and inner surfaces of the solid earth formed by the upper half annular hollow space is located in each of the chambers. Thrust generating means is connected between the respective excavating machines and the respective gripper means so that the excavating machines can be advanced by the action of the thrust generating means when the gripper means is actuated to abut against the earth.
Field of SearchStepper-type advance-causing means