Rotary mine boring head having movable links with cutter bits

A continuous mining machine comprising:

• a mobile frame;
• a longitudinal conveyor mounted on said frame having a forwardly opening throat adjacent the floor level;
• a support frame for boring heads mounted on said mobile frame;
• at least two rotary boring heads mounted on said support frame so as to rotate about spaced parallel axes in order to cut contiguous bores in advance of said machine, each boring head having at least one rotor arm which carries and supports cutter bits on the front thereof;
• a pair of reciprocating poles mounted in each rotor arm for movement in the radial direction of the arm;
• link members each pivotally connected at opposite ends thereof to a respective pair of said poles;
• cutter bits mounted on each link member;
• a cam follower mounted on each reciprocating pole;
• and
• a generally flat cam structure mounted on said support frame behind each boring head and having a continuous, lobed track formed in the front thereof, wherein the cam followers move along said track and cause each pair of poles to be pushed radially outwardly at each of several corners distributed about a circular hole cut by the respective boring head in such a manner that the resulting hole bored by said machine has generally flat sides.

A rotary boring head apparatus for a continuous mining or excavating machine comprising:

• a central hub,
• a plurality of radially extending rotor arms connected to said hub and capable of carrying cutter bits on the front thereof,
• a pair of reciprocating pole devices mounted in each of said rotor arms for movement in the radial direction of the arm;
• a number of link members each pivotally connected at opposite ends thereof to a respective pair of said pole devices;
• additional cutter bits mounted on said link members;
• and
• means for reciprocating each pair of pole devices as said boring head is rotated, said reciprocating means being capable of pushing each pair of pole devices radially outwardly at each of four corners distributed about a circular hole cut by the boring head in such a manner that the resulting hole bored by said machine is generally rectangular.