Road planar

An excavation machine for planing a surface of the earth, comprising:

• a main frame, an elongated digging apparatus that includes a superstructure that forms an extension arm having a near end opposed to a far end, with the near end having means by which it is pivotally attached at one end of said main frame, a prime mover mounted at the other end of said main frame;
• means by which a pair of spaced sprockets are supported at each of the opposed ends of said extension arm;
• an endless digging member comprising two parallel spaced endless chains meshed with said sprockets and supporting a plurality of cutter plates which are affixed to the outer surface of the endless chains;
• means rotatably supporting said sprockets at the near and far end of said extension arm, said sprockets at the far end of said extension arm are axially aligned with said endless digging member being located therebetween to thereby form the central part of a digging head;
• said digging head includes drum means affixed to opposed sides of said sprockets at the far end of said extension arm, an auger flight formed about each drum periphery, cutting teeth arranged in mounted relationship on the periphery of said auger flight and on said cutter plates;
• the flights on opposed sides of the sprockets are of a pitch to cause excavated material to move towards the endless digging member;
• conveyor means including said endless digging member by which excavated material is forced to move upwardly toward the main frame and then laterally away from said machine;
• a curved shield assembly extending laterally the entire width of the drum means, said shield assembly circumferentially extends a limited circumferential distance about the digging head, said shield assembly is in the form of a first segment of a cylinder, means by which said first segment is supported in fixed relationship by the far end of said elongated arm in close proximity to said digging head;
• said shield assembly includes another segment of a cylinder which is slidably received by the first segment, said another segment has a lower end which terminates in a support shoe, said support shoe engages the ground to support the digging head and thereby control the depth of the excavation, and means for extending and retracting said another segment respective to said first segment and the digging head to thereby adjust the elevation of the digging head;
• said means for moving said machine is spaced endless tracks arranged on opposed sides of said main frame, said elongated arm is journaled to said main frame and includes means attached thereto for pivoting the digging head from a position above the ground to a position below ground level.

In a digging machine for planing a road or the like, said machine having endless tracks mounted to support a main frame;

• means, including a prime mover and drive train, for moving said machine along the ground, the improvement comprising:
• an elongated digging apparatus including an elongated support arm having a near end and a far end, axially spaced drive sprocket means mounted at the near end of the support arm, and an elongated shaft mounted at the far end thereof, said shaft having opposed ends, means pivotally mounting the near end of said support arm to said main frame;
• axially aligned spaced sprockets rotatably mounted on said shaft;
• a digging head supported by said shaft, spaced endless chains connected about the sprockets at the near and far ends of the support apparatus, means by which a plurality of digging teeth are supported by said endless chains which jointly form an endless central digging and conveying member;
• the far end of said central digging and conveying member forms part of said digging head;
• said digging head includes spaced drums mounted in axial aligned relationship for rotation on opposed marginal ends of the shaft, means connecting the drums to be rotated by the far end sprockets;
• flights formed on said drums;
• digging teeth mounted on the drum flights for excavating geological formations;
• said digging teeth are aligned in a circular configuration that describes a cylinder, whereby the teeth on one side of each of the drums simultaneously engage and dig into the ground;
• said flights on opposed sides of the shaft are of a pitch to cause excavated material to move towards the endless digging member;
• means including said central digging and conveying member by which any excavated material is moved to a higher elevation where the excavated material is then moved laterally away from proximity of the digging machine;
• a shield and support means is mounted at said far end of said support arm and extends circumferentially around part of the digging head and into contact with the ground, said shield means comprises a first and a second coacting segment of a cylinder having an axis that coincides with the axis of the digging head;
• said shield means includes a curved fixed segment which is attached to support the far end of the support arm and extends downwardly towards the ground and slidably supports said movable segment;
• said fixed and movable segments form a segment of a cylinder which can be adjusted in circumferiential length;
• means connecting the two segments together for movement in a slidable manner respective to one another to thereby selectively change the circumference of the shield;
• means forming a shoe at the lower end of the slidable segment, said shoe engages the ground and supports the digging head at a selected elevation to control the depth of the excavation as the two segments move respective to one another.