Method and apparatus for cooling chain type diggers

A digging machine for excavating material from the ground comprising a main frame having a prime mover supported thereon, a drive train connected for moving said machine along the ground;

• an elongated digging apparatus that includes a boom having a near end opposed to a far end, an upper boom surface opposed to a lower boom surface, and opposed sides that form a hollow interior, means mounting an endless digging and conveying member for longitudinal movement on said boom to provide an upper run at said upper boom surface, and a lower run at said lower boom surface, with said lower run adapted to engage and excavate the ground;
• means for receiving excavated material from the endless digging and conveying member and moving the excavated material from proximity of the digging machine;
• the improvement comprising:
• said lower boom surface is separated from said lower run by a plurality of wear plates;
• mount means by which said wear plates are arranged laterally respective to the lower run and in parallel relationship respective to one another;
• said plurality of wear plates being mounted in captured relationship respective to said lower boom surface at a location closely adjacent and spaced from said far end and remotely spaced from said near end;
• and,
• a heat transfer liquid within the boom hollow interior for transferring heat generated by the lower run of the endless digging and conveying member away from the lower boom surface to a relatively cooler part of the boom and thereby reduce the temperature of the lower boom surface.

A ground supported excavating machine for excavating material from the earth, comprising:

• a main frame having a prime mover and drive train for moving said machine along the ground;
• a digging apparatus that includes an elongated boom having opposed ends, a head shaft mounted at one end of said boom and a tail shaft mounted at the opposed end of the boom;
• said one end of said boom is attached to said main frame and said opposed end depends therefrom;
• said boom has an upper surface opposed to a lower surface;
• an endless digging chain supported for movement on said boom between the head and tail shafts and having a tight lower run that rubs against the boom lower surface;
• a plurality of wear plates of rectangular configuration, each presenting a central body part and opposed ends;
• means, including an attachment on said central body part of each of said plurality of wear plates, by which said plurality of wear plates are mounted in underlying relationship respective to said boom lower surface;
• spaced anchor plates attached to said lower surface of said boom, a tendon having opposed ends received by said spaced anchor plates and arranged to place said tendon parallel to said lower run;
• said attachment is connected to said tendon to orient each of said wear plates laterally respective to the lower run and in parallel relationship respective to one another.

In a ground supported excavating machine of the type having a main frame and a prime mover for propelling the machine along the ground, a boom supported from the frame and having an upper surface and a lower surface and an endless digging member rotated by a head shaft mounted at one end of said boom and a tail shaft mounted at the opposed end thereof to provide a lower run that engages the lower surface of the boom and thereby raises the temperature of the lower surface respective to the upper surface;

• the method of reducing the rate of wear of the co-acting parts associated with the endless digging member comprising the steps of:
• making the interior of the boom into a liquid container that communicates with the lower surface of the boom, and filling the interior with sufficient heat transfer liquid to thereby transfer heat from the relatively hot boom lower surface to a relatively cold boom upper surface;
• removably mounting a plurality of wear plates having upper and lower faces in captured relationship respective to the lower surface of the boom and thereby cover a marginal length of the lower surface of the boom at a location adjacent the tail shaft, and isolating an upper face of the wear plates from the lower surface of the boom by suspending the wear plates for loosely contacting the lower surface of the boom with very little force respective to the force with which the lower run engages the lower face of the wear plates while digging.