Abstract: In a power shovel having a main support unit, a front end assembly operatively connected to the main support unit and a rope crowd system mounted on the main support unit and operatively connected to the front end assembly, a crowd drive assembly for the rope crowd system comprising a rope drum mounted on a support frame supported on the main support unit, a drive shaft journaled in the support frame adjacent the tangential point of the crowd rope wound on the rope drum, transversely spaced means disposed on the drive shaft for transmitting torque to the rope drum and an appropriate motor and gear arrangement supported on the main support unit for driving the drive shaft.

Abstract: A power shovel generally consisting of a support unit, a stiffleg operatively connected to the support unit for pivotal movement about a stiffleg pivot axis, a handle operatively connected to the stiffleg for pivotal movement about a handle pivot axis, a dipper mounted on the handle, a crowd system operatively connected to the handle for crowding and retracting the dipper and a hoist system for hoisting and lowering the dipper comprising at least one upper fluid actuated rod and cylinder assembly operatively connected at a lower end to the stiffleg and operatively connected at an upper end thereof to the handle on one side of the handle pivot axis, at least one lower fluid actuated rod and cylinder assembly operatively connected at a lower end thereof to the stiffleg and operatively connected at an upper end thereof to the handle on a side opposite to the operative connection of the upper end of the upper fluid actuated assembly to the handle, relative to the handle pivot axis, and apparatus for selectively s

Abstract: In a power shovel having a main frame, a front end assembly operatively connected to the main frame and a rope crowd system including a rope drum supported on the main frame, a motor supported on the main frame drivingly connected to the rope drum, a brake operatively connected to the rope drum and a rope wound on the drum and operatively connected to the front end assembly, a system for preventing the rope from becoming slack comprising apparatus responsive to an impending slack condition of the rope for actuating the drum brake thereby preventing continued pay out of the rope by the drum and apparatus responsive to motor torque in a pay-out direction for disengaging the motor from the rope drum, allowing the motor to continue to operate in the pay-out direction when said drum brake is actuated.

Abstract: In a large, heavy-duty machine such as a power shovel and the like, having a lower frame, an upper frame and a live roller circle including a lower rail mounted on the lower frame, a roller cage structure, a plurality of pins mounted on the cage structure, rollers mounted on the pins of the cage structure and supported in rolling contact with the roller rail and an upper rail mounted on the upper frame and supported on the rollers, wherein the center of gravity of the machine travels beyond the live roller circle during normal operating conditions, the improvement comprising a set of at least two cylindrical rollers mounted on each pin of the cage structure of the roller circle.

Abstract: In a power shovel having a lower frame and an upper frame rotatably supported on the lower frame, a center pin assembly for carrying radial and axial loads imposed on the upper frame comprising a downwardly opening socket mounted on the lower frame, a pin disposed on the axis of rotation of the upper frame, the pin having a center section and an annular section, the center pin section having an upper end rigidly secured to the upper frame and a lower portion extending downwardly into the socket, the annular pin section being interposed between the socket and the lower end of the center pin section, the annular pin section and the socket having bearing contact surfaces, axially spaced, annular sealing rings disposed between the lower portion of the center pin section and the annular pin section providing an annular variable volume chamber therebetween and means for supplying a measured volume of fluid to the variable volume chamber to effect a predetermined displacement between the center pin section and the a

Abstract: A power shovel comprising a support unit: a stiffleg operatively connected to the support unit for pivotal movement about a stiffleg pivot axis, the stiffleg comprising a pair of transversely spaced, longitudinally disposed side beams each having an I-shaped cross-sectional configuration including upper and lower flange portions and an interconnecting web portion, a cross-piece section interconnecting the side beam sections and a web section interconnecting the web portions of the side beam sections; a handle operatively connected to the stiffleg for pivotal movement about a handle pivot axis; a dipper mounted on the handle; a crowd system operatively connected to the handle for crowding and retracting the dipper; and a hoist system for hoisting and lowering the dipper comprising at least one upper fluid actuated rod and cylinder assembly operatively connected at a lower end thereof to the stiffleg and operatively connected at an upper end thereof to the handle on one side of the handle pivot axis, at least o

Abstract: A power shovel including a stiffleg, a dipper handle operatively connected to the stiffleg, a dipper having a forwardly disposed digging end pivotally connected to the dipper handle, the dipper being biased to pitch the forwardly disposed digging end thereof upwardly, means for limiting the upward pitch of the digging end of the dipper relative to the dipper handle, a hoist frame pivotally connected to the stiffleg, and a hoist link pivotally connected at the ends thereof to the hoist frame defining a four bar linkage.

Abstract: A bail assembly for a rope drive mechanism is described which operates to equalize the loads on the ropes extending through it and minimize bending of those ropes. Two ropes are looped through the bail around small sheaves which are rotatably mounted on a double eccentric shaft. The ropes are guided to and from the sheaves in the same plane. The bail assembly is mounted to align itself with the plane of the ropes, and it is balanced so that its weight will not bend the ropes under slack conditions. Provisions are made for the bail assembly to operate to remove slack in the ropes by exerting its weight on the ropes.

Abstract: In a power shovel including a base unit; a support unit rotatably mounted on the base unit; a front end assembly including a stiffleg pivotally connected at a lower end thereof to the support unit, a dipper handle operatively connected to the stiffleg, a dipper pivotally connected to the dipper handle, a hoist frame pivotally connected to the stiffleg, and a hoist link pivotally connected at the ends thereof to the hoist frame and the dipper, the dipper handle, dipper, hoist link and hoist frame defining a four bar linkage; a crowd system operatively interconnecting the support unit and the front end assembly; a hoist system operatively interconnecting the support unit and the front end assembly; and control means mounted on the support means for operating the crowd and hoist systems to crowd, hoist, lower and retract the dipper, a pitch stop assembly comprising a collapsible tension member interconnecting the hoist link and dipper of the front end assembly for limiting the angular displacement of the dipper

Abstract: A power shovel comprising a body; a front end assembly mounted on the body including a dipper; means for crowding the dipper; means for hoisting the dipper; and an energy regeneration system including an energy storing means and means actuated by a predetermined movement of at least one component of the front end assembly for charging the energy storing means, the energy storing means providing in the loaded condition a force applicable to a component of the front end assembly for at least biasing such component toward a predetermined movement.

Abstract: A power shovel including a stiffleg, a dipper handle operatively connected to the stiffleg, a dipper having a forwardly disposed digging end pivotally connected to the dipper handle, the dipper being biased to pitch the forwardly disposed digging end thereof upwardly, means for limiting the upward pitch of the digging end of the dipper relative to the dipper handle, a hoist frame pivotally connected to the stiffleg, and a hoist link pivotally connected at the ends thereof to the hoist frame and to the dipper defining a four bar linkage.

Abstract: A crowd system for a power shovel having a front end assembly including a dipper mounted on a body, and means mounted on the body and operatively connected to the front end assembly for hoisting and lowering the dipper, comprising a mast pivotally connected at a lower end thereof to the body, at least one connecting link pivotally connected at opposite end thereof to the mast and the front end assembly, at least one support link pivotally connected at a lower end thereof to the body, a drive link pivotally connected at opposite end thereof to the mast and the support link, a gantry mounted on the body between the mast and the support link, at least one fluid actuated, piston and cylinder assembly pivotally connected at one end thereof to the gantry at a point elevated relative to a support platform of the body, and pivotally connected at the opposite end thereof to the drive link, and means for selectively supplying fluid under pressure to the opposite ends of the cylinder of the piston and cylinder assembly

Abstract: A machine of the dragline, shovel, or crane type having a body rotatably mounted upon a base with a padded live roller circle interposed between the body and base to facilitate rotation of the body. The roller circle includes flat, segmental upper and lower rails with resilient and compressible pads between the rail segments and the respective body and base, and a roller cage between the rails having rollers which are generally cylindrical and in bearing contact with the rails, the rail segment pads permitting movement of the segments to distribute local loads to adjacent rollers. The rails are clamped to the body and base by means of yieldable clamping means, and the cage is guided in its circular travel path by yieldable guide means.

Abstract: In a power shovel having a crowd system for crowding and retracting a dipper and a hoist system for hoisting and lowering such a dipper, a system for limiting the motion of the dipper generally comprising means operatively interconnecting a crowd componment movable between predetermined crowd and retract limits and crowd control lever responsive to a movement of the crowd component between the pedetermined limits of movement thereof for increasingly biasing the crowd control lever steadily away from an operative position thereof, as the crowd component approaches one of the predetermined limits of movement thereof, means operatively interconnecting a hoist control lever and a hoist component movable between predetermined upper and lower limits responsive to a movement of the hoist component between the limits of movement thereof for increasingly biasing the hoist control lever steadily away from an operative position thereof as the hoist component approaches one of the predetermined limits of movement thereof

Abstract: A power shovel comprising a body; a front end assembly mounted on the body including a dipper; means for crowding the dipper; means for hoisting the dipper; and an energy regeneration system including an energy storing means and means actuated by a predetermined movement of at least one component of the front end assembly for charging the energy storing means, the energy storing means providing in the loaded condition a force applicable to a component of the front end assembly for at least biasing such component toward a predetermined movement.