Coal mining apparatus and method
Casting of structural walls
Trenching apparatus and methods of forming inground retaining walls
System for guiding the excavation tool used for constructing a wall cast in the ground Patent #: 4930940
ApplicationNo. 729920 filed on 07/15/1991
US Classes:37/362, Drive-related feature37/355, Longitudinal cut37/357, With distinct rotary digger405/267Filling substerranean cavity (e.g., underground wall)
ExaminersPrimary: Reese, Randolph A.
Assistant: McBee, J. Russell
Attorney, Agent or Firm
International ClassesE02F 003/14
Foreign Application Priority Data1986-06-13 AU
AbstractPropulsion apparatus is disclosed for urging a trenching arm forward against the advancing face of an elongate trench being dug by the trenching arm. The propulsion apparatus includes a propulsion member which is engageable with the base wall of the trench such that the trenching arm may be urged forward relative to the engaged propulsion member. The propulsion member may then be withdrawn from engagement with the base wall and retracted towards the trenching arm before commencing a further propulsion cycle. The propulsion member is also operable to cooperate with the trenching arm in excavating a starting slot at the beginning of a new trench.