Abstract: A swing drive system for a surface mining shovel comprising an alternating current motor having a plurality of distributed rotor coils mounted on the lower body and a plurality of distributed stator coils connected to a power supply and mounted on the upper frame. Operation of the motor causes the upper body to rotate or swing relative to the stationary lower body. The rotatable upper frame and thereby the stator coils are movably supported on a circular track forming part of the lower stationary body by means of rollers positioned between the upper frame and the lower body. The upper frame may have a circular track facing the lower track and the rollers then roll on the lower circular track in engagement with both the upper and lower circular tracks to rotatably support the upper frame on the lower body. The rotor coils are preferably positioned between the rollers and the stator coils. The motor is supplied with three phase A.C.

Abstract: A crawler track guide rail having an upper elongated surface engagable with the shoes of a crawler track, a lower surface engagable with a crawler track support frame, and a foot which extends downward into the frame to transfer load resulting from the engagement of the shoes with the guide rail to the frame. The guide rail has at least one elongated lower surface and may have two elongated lower surfaces which are engageable with the frame. Where there are two elongated surfaces of the guide rail in engagement with the frame, the foot of the guide rail is positioned between the two elongated surfaces. The guide rail has a plurality of fasteners for retaining it on the crawler frame extending through the guide rail and the frame The fasteners have a selected tolerance fit with the frame and the foot of the guide rail has a smaller tolerance fit with the frame than that of the fasteners.

Abstract: A draglined bucket having first and second contoured dumping rails respectively supported on first and second spaced apart opposite sidewalls and a rear wall. Each dumping rail extends from above the sidewall on which it is supported to the rear wall on which it is also supported. Rollers are connected to a hoist rope and support the bucket in a suspended manner. The rollers engage the first and second dumping rails and are movable along the dumping rails from a forward position in which an open end of the bucket faces substantially horizontally, to a rearward position in which the open end of the bucket faces downwardly to dump material in it. The dumping rails adjacent to the rear wall of the bucket are preferably spaced from the rear wall of the bucket. The rollers include first and second rollers which respectively engage the undersides of the first and second dumping rails.

Abstract: A system having two or more A.C. motors driving the same load. The stator windings and rotors of both motors each conduct current having a vector representative of a magnitude and angular position of the current in the respective rotor and stator winding. Stator current sensors are provided for producing an indication of the magnitude of the stator current vector to each motor. Encoders are provided for sensing the rotating speed of each of the rotors from which can be calculated the angular position of the rotor load current vector with respect to the rotating stator flux current vector. A first torque control controls the magnitude of the stator current of a first one of the motors such that the stator flux current vector of the first motor and the rotor load current vector of the first motor are angularly separated by 90.degree.. This angular relationship produces maximum torque at the rotating speed of the first motor.

Abstract: An indicating device is provided which includes a pivotal member mounted on a base plate attached to the frame of the trolley on which the hoist is supported, and a pair of spaced apart projections extending from the pivotal member and between which a rope for lifting a load is disposed at a desired orientation relative to the vertical. Movement of the rope from the desired orientation will cause it to engage one of the rods and move the rod along with the pivotal member in one of two opposite directions depending on the direction of movement of the rope from its desired orientation. A pair of fixed members are also mounted on the base plate and are each positioned in a different one of the two opposite directions of movement of the pivotal member.

Abstract: A grease applicator for the threaded joint section of a drill shaft of a blasthole drill. The grease applicator has a grease applicator head movable to an application position adjacent the threaded section of the drill shaft by an applicator drive. The drive extends the applicator head to and extracts the applicator head from the application position. When the applicator head is at the application position, a propelling device for moving grease through the applicator head into engagement with the threaded section is activated to apply the grease to the threaded section. To distribute the grease over the threaded section, the applicator head may have a shape partially surrounding the threaded section. The threaded joint section is vertically positioned in the path of movement of the grease applicator head and the applicator head is extended by the applicator drive along a path toward the threaded section.

Abstract: A joint container for forming a weld joint utilizing multiple adjacent metal plates which are spaced apart and positioned angularly to each other. One of the plates forming the joint may extend continuously through the joints along a straight line. At least first and second plates of the multiple plates may be at an acute angle to each other. A dam member is placed in each of the spaces between each two adjacent plates. The dam member between adjacent plates has a concave contour surface viewed in a direction toward the weld joint container. Thereby stress inducing sharp corners in the finished weld joint are minimized due to the reduction of the angles of the corners provided by the contour of each dam surface when it engages one of the plates. Also, the plates having ends at the joint have such ends cut parallel to and spaced from the plate extending continuously straight through the joint.

Abstract: A tumbler drive mechanism having a rotatable tumbler body mounted on a shaft and a plurality of tumbler lugs removably mounted on the tumbler body. The shaft has a longitudinal axis about which it and the tumbler rotate. The tumbler body includes a center drum and a plurality of circumferentially spaced apart radially projecting drive flanges. Each one of the plurality of tumbler lugs is mounted between and in engagement with two adjacent ones of the plurality of drive flanges. Each of the tumbler lugs engages the shoe lugs of a crawler track as the tumbler body rotates to drive the crawler track. The tumbler lug is mounted on the tumbler body at a selectively variable radial distance from the axis of the tumbler body. The radial distance at which the tumbler lugs are mounted on the tumbler body is accomplished by providing one or more shims positioned between the lug and the tumbler body.

Abstract: A gantry crane travelable along a pair of rails and having an overhead girder transverse to the direction of travel, first and second legs connected to the girder, a load carrying trolley movable along the girder to a first position adjacent the first leg and to a second position adjacent the second leg, first and second spaced apart motor drives mounted on one of the legs in engagement with one of the rails for moving the crane, and third and fourth spaced apart motor drives mounted on the other leg in engagement with the other rail for moving the crane. When the trolley is at the first position, the first and second drives are highly loaded and the third and fourth drives are lightly loaded. Thereby, the lightly loaded drives attempt to drive the second leg such that it leads the first leg and skews the crane. When the trolley is at the second position, the third and fourth drives are highly loaded and the first and second motor drives are lightly loaded.

Abstract: A material hauler including a first material carrier having wheels for supporting the carrier and permitting its movement along a floor surface and a second material carrier removably supported on a material handling vehicle and positioned at a distance from the first material carrier. The material object to be hauled bridges the space between the first and second material carriers and engages both of the material carriers. Thereby, the two material carriers and the material object all travel with the material handling vehicle to haul the objects. The second material carrier can be lifted above the floor surface by the material handling vehicle and includes a lower member supported on the material handling vehicle and an upper member which is pivotal relative to the lower member. The upper member supports the material object being hauled so that the lower member and the material handling vehicle can turn at corners relative to the upper member and the material object.

Abstract: A hoist having an alternating current induction motor for rotating the drum of the hoist and an adjustable frequency power supply connected to the motor has a first control connected to the adjustable frequency power supply for directing the power supply to provide power to the motor at a first voltage level at the initiation of a raising operation. A second control is also connected to the adjustable frequency power supply for directing the power supply to provide power to the motor at the initiation of a lowering operation at a second voltage level which is lower than the first voltage level. The voltage level supplied to the hoist at the initiation of a raising operation may comprise a voltage level which is increased by a raising o first voltage boost value above the voltage level that would be applied without the first voltage boost value. At the initiation of a raising operation, the first voltage level may include a first voltage boost value.

Abstract: A control for a d.c. motor having a d.c. thyristor power supply connected to a d.c. motor and a control circuit for selectively varying and controlling the level of the current provided by the thyristor power supply to the motor. The thyristor power supply provides a plurality of selected output current levels to the motor and the motor has a corresponding plurality of torque levels. The level of the output current supplied by the power supply to the motor is independent of the resistance in the motor circuit. The motor is rotatable in opposite directions and the thyristor power supply will provide output voltage at opposite pluralities corresponding to the rotational direction of the motor.

Abstract: The invention is an improvement in a tooth assembly used with excavating and digging buckets such as those found in draglines, backhoes and the like. Such tooth assemblies include a top portion (such as a wear cap), a nose protruding beyond the portion and a digging tip. The tip has high-hardness upper and lower exterior wear surfaces and a sharp-edged tip end for biting into earth, mineral and rock. Either embodiment of the improved assembly involves mounting parts (a tip or tip and sleeve) directly on the nose. In one improved assembly, a sleeve is interposed between the tip and the portion and includes high-hardness wear surfaces extending between tip and portion. The tooth and sleeve cooperate to substantially entirely shroud the nose. In another version having no sleeve, the tip includes high-hardness active digging surfaces extending substantially entirely rather than only partially between the portion and the tip end.

Abstract: A support apparatus for the operator's cab of an overhead crane. The crane has a rigid depending mast and an intermediate mast and carriage vertically movable on the rigid mast for lifting and carrying a load. A hoist is mounted on the crane and attached to the carriage for raising and lowering the carriage, the intermediate mast and the load at normal operating speeds. The support apparatus includes a first support affixed to the cab and the intermediate mast for supporting the cab on the intermediate mast during normal operating speeds of the intermediate mast. The first support permits detaching the cab from the intermediate mast upon the occurrence of an excessive lowering operating speed of the intermediate mast. A second support affixed to the cab and to an overhead support of the crane then supports the cab in a suspended manner and the intermediate mast drops toward the floor below the crane without the cab.

Abstract: A skew correcting apparatus for a crane having drive wheels traveling on spaced apart rails which are independently driven. Each one of the drive wheels has an axially extending single diameter cylindrical surface and first and second axially spaced apart radially extending circumferential flanges. The spacing distance of the first flange of each of the first and second wheels is such that, when the crane is in one of the skewed positions the first flange of the leading wheel in the direction of travel engages the faced outer side of the rail head and the engagement of the second flange of the lagging one of the wheels with the inner rail side which it faces is minimized. Each rail head has a shoulder surface including a radius defining a cross-sectional shoulder curvature. The first flange of each one of the wheels also includes a circumferential flange juncture surface adjoining the cylindrical surface.

Abstract: The invention is carried out by providing an adjustable frequency power supply connected to an alternating current induction motor which is rotated at speeds in excess of 60 hertz. A plurality of sequential frequency ranges are selected which, together, comprise a total frequency range from a maximum frequency range in excess of 60 hertz to 60 hertz which is applied to the motor. For each frequency range, a maximum breakdown torque of the motor is determined. When it is desired to decrease the speed of the motor, it is decelerated sequentially through each frequency range at a different deceleration rate for each range such that the maximum breakdown torque of the motor within each frequency range is not exceeded. Each different deceleration rate for each frequency range is determined by selecting the minimum period of time, for each frequency range, during which the motor may be decelerated without exceeding the maximum breakdown torque of the motor within that frequency range.

Abstract: A storage and retrieval machine having a base movable in opposite horizontal directions, a mast mounted on the base, and a carriage movable in opposite vertical directions on the mast. A drive is also provided for moving the base and carriage in their respective opposite horizontal directions or opposite vertical directions. A control is connected to the drive for transmitting to the drive for either the base or the carriage, a first signal for a fast acceleration rate in one of the opposite directions of movement, a second signal for a slow acceleration rate in the other of the opposite directions of movement, a third signal for a slow deceleration rate in one of the opposite directions of movement, a fourth signal for a fast deceleration rate in the other of the opposite directions of movement, and a direction signal to move in one of the opposite directions.

Abstract: A wheel assembly for a storage and retrieval machine which is travelable on a rail along a path adjacent overhead storage locations which store objects delivered to and retrieved from the locations by the storage and retrieval machine. The storage and retrieval machine includes a base which is supported on the rail by the wheel assembly. The wheel assembly comprises a wheel engaging the rail and having a horizontal axis of rotation and an upwardly extending axis projecting through the wheel. A wheel support is affixed to the base and includes a bracket on which the wheel is mounted. The bracket has a plate member extending laterally of and around the upwardly extending axis of the wheel. A positioning mechanism is provided for angularly positioning the wheel about the upwardly extending axis and has a plurality of set screws spaced from and in a surrounding relationship to the upwardly extending axis and engaging the plate member of the bracket upon which the wheel is mounted.

Abstract: A hoist drive for a double hoist carrying member having a hold hoist drum, a hold rope connected to the hold hoist drum and from which the carrying member is suspended, and a hold motor for rotating the hold hoist drum to raise and lower the carrying member. The hoist drive further includes a close hoist drum, a close rope connected to the close hoist drum and from which the carrying member is suspended, and a close motor for rotating the close hoist drum to raise and lower the carrying member. During raising of the carrying member, the hold and close motors are each supplied with a.c. power at different preselected frequencies. The hold and close motors each operate along a first pair of intersecting frequency to torque curves during a raising operation in which the hold motor curve is steeper than the close motor curve.

Abstract: A skew correcting apparatus for a crane supported on spaced apart generally parallel rails by a plurality of wheels including a drive wheel traveling on each of the parallel rails. The drive wheels traveling on the spaced apart rails are driven such that they rotate at the same speed. One of the drive wheels has an axially extending single diameter cylindrical surface engaging the top side of the rail head and a radially extending circumferential flange facing the inner side of the rail head. In one of the skewed positions of the crane, one of the wheels lags the other of the wheels and is subject to high levels of skew force such that the flange of the lagging wheel and the inner side of the rail head it faces engage each other. Each one of the wheels also includes a flange juncture surface joining the cylindrical surface of the flange of each wheel.