Abstract: An improved lock ring and spreader tool affording a method of removing the lock ring from a circumferential groove on a rim, the lock ring serving to retain a tire flange in position on the rim, the lock ring being split with juxtaposed ends each having a slot therein, the bottom of the slots being of concave configuration, and a spreader tool having opposed jaws, the jaws being receivable in the slots in the lock ring and the jaws having convex surfaces thereon, the spreader tool jaws being moveable apart so that the tool when inserted in the slots in the lock ring, serves to force the ends thereof apart, expanding the diameter of the lock ring and permitting its expeditious removal from the circumferential groove.

Abstract: An improved tire rim clamp for retaining the dual tires and rims of a large mining truck or the like comprising a cylindrical member having a plurality of slotted openings circumferentially distributed around the inner beveled edge of the cylinder and a circular retention bolt flange extending radially inward at the other end of the cylinder such that the tire rim clamp can occupy the annulus formed between the axle housing and outer tire rim when bolted in place. Such a one piece tire rim clamp can be inserted into the outer tire rim when mounted to the axle housing using powered equipment, thus eliminating the difficult manual task of inserting and positioning a plurality of individual tire clamps during assembly or the servicing of the dual tires on a mining truck or the like.

Abstract: An improved rim for use on a heavy, off-road vehicle formed of a tubular rim base member having a circumferential groove in the outer cylindrical surface adjacent one end thereof, the groove being of semi-circular cross-sectional configuration, a first bead flange secured at one end of the rim base member, a second bead flange slidably mounted on the other end of the rim base providing a contour substantially the same as the inner contour of the first bead flange, the second bead flange having a circumferential recess in the inside surface at the outer end thereof, and a split circular cross-sectioned locking ring removably received within the base member circumferential groove so that when the second bead flange is slidably positioned on the rim base, the locking ring can be placed in the groove and when the second flange slides outwardly the recess therein retains the locking ring within the groove and the locking ring serves to retain the second bead flange on the rim.

Abstract: An improved drive system for large mining trucks employing combined diesel/electric propulsion or the like wherein AC current generated by the alternator is rectified before powering wheel motors and wherein the wheel motors are used as generators to produce a retarding current that is directed to a resistive grid with plurality of shunting circuits thus extending the retard torque during dynamic braking and deceleration of the vehicle wherein the improvement comprises the use of silicon controlled rectifiers (SCR's) rather than contactors to achieve the desired electric circuit arrangement and in particular wherein four SCR's are used in the resistive grid to achieve a seven stage extension of the retarding torque and wherein the SCR's in the DC circuit are deactivated (opened) by back biasing with an SCR circuit that delivers AC current from the alternator to the cathode of a switching SCR in the retarding circuit.