초록 ▼

A rear wheel steering apparatus for steering the rear wheels of a vehicle supported on a multi-link suspension includes a live axle and a track bar pivotally connecting the axle to a vehicle frame. Steering knuckles at opposite ends of the axle support road wheels for rotation and for steering. Stee

A rear wheel steering apparatus for steering the rear wheels of a vehicle supported on a multi-link suspension includes a live axle and a track bar pivotally connecting the axle to a vehicle frame. Steering knuckles at opposite ends of the axle support road wheels for rotation and for steering. Steering arms extend from the steering knuckles and a drag link extends between and interconnects the steering arms. An actuator is connected between the frame and the drag link and steers the rear road wheels by alternately pushing and pulling on the drag link.

대표청구항 ▼

A rear wheel steering apparatus for steering the rear wheels of a vehicle supported on a multi-link suspension includes a live axle and a track bar pivotally connecting the axle to a vehicle frame. Steering knuckles at opposite ends of the axle support road wheels for rotation and for steering. Stee

A rear wheel steering apparatus for steering the rear wheels of a vehicle supported on a multi-link suspension includes a live axle and a track bar pivotally connecting the axle to a vehicle frame. Steering knuckles at opposite ends of the axle support road wheels for rotation and for steering. Steering arms extend from the steering knuckles and a drag link extends between and interconnects the steering arms. An actuator is connected between the frame and the drag link and steers the rear road wheels by alternately pushing and pulling on the drag link. mprises natural diamond grit. 5. The rotary drag bit of claim 1, wherein the discrete cutting structures are configured as posts. 6. The rotary drag bit of claim 5, wherein the posts include bases of larger cross-sectional area than outermost ends thereof. 7. The rotary drag bit of claim 6, wherein the posts taper from substantially circular outermost ends to substantially oval bases. 8. The rotary drag bit of claim 5, wherein the posts exhibit a constant cross-sectional area. 9. The rotary drag bit of claim 1, wherein at least one of the plurality of discrete cutting structures is formed as a hot isostatic segment. 10. The rotary drag bit of claim 9, wherein the at least one discrete cutting structure is brazed onto the blade. 11. The rotary drag bit of claim 1, further including a plurality of ports opening onto the bit face and in communication with a plurality of fluid passages respectively disposed between the blades. 12. The rotary drag bit of claim 1, wherein at least one of the blades extends to a location proximate the centerline, and the PDC cutters are carried by the at least one blade. 13. The rotary drag bit of claim 12, wherein two of the blades extend to locations proximate the centerline wherein at least one PDC cutter is carried on each of the extended blades. 14. The rotary drag bit of claim 1, wherein the bit body comprises a matrix bit body, and the blades are integral with the bit body. 15. The rotary drag bit of claim 14, wherein the discrete cutting structures are integral with the blades and the bit body. 16. The rotary drag bit of claim 15, wherein the discrete cutting structures are comprised of a metal matrix material carrying the diamond grit and at least a portion of the blades is comprised of a softer and more abradable metal matrix material than that of the metal matrix material present in bases of the blades. 17. The rotary drag bit of claim 14, wherein the discrete cutting structures are brazed onto the blades. 18. The rotary drag bit of claim 14, wherein the discrete cutting structures are funaced onto the blades. 19. The rotary drag bit of claim 1, wherein the PDC cutters are oriented with cutting faces substantially facing in a direction of intended bit rotation. 20. The rotary drag bit of claim 19, wherein the PDC cutters include PDC sheaths contiguous with, and extending to the rear of, the cutting faces, taken in the direction of intended bit rotation, extending over substrates of the PDC cutters. 21. The rotary drag bit of claim 1, wherein the blades extend radially outwardly over the bit face in substantially linear fashion. 22. The rotary drag bit of claim 1, wherein the blades extend radially outwardly in spiral fashion. 23. The rotary drag bit of claim 1, wherein the blades extend radially outwardly in a serpentine fashion. 24. A rotary drag bit for drilling subterranean formations, comprising: a bit body having a face extending from a centerline to a gage; a plurality of discrete, mutually separated posts comprising a particulate abrasive material protruding upwardly from the face, wherein the plurality of posts include bases of larger cross-sectional area than outermost ends thereof, wherein the base of at least one of the plurality of posts exhibits a noncircular cross-sectional area. 25. The rotary drag bit of claim 24, wherein the posts are integrally formed with the bit face. 26. The rotary drag bit of claim 25, wherein the bit body comprises a matrix bit body. 27. The rotary drag bit of claim 24, further comprising a plurality of blades on the face extending generally radially outwardly toward the gage, each blade having at least one of the plurality of posts positioned thereon. 28. The rotary drag bit of claim 27, wherein the posts are integrally formed with the blades. 29. The rotary drag bit of claim 28, wherein the blades extend radially outwardly over the bit face in substantially linear fashion. 30. The rotary drag bit of claim 28, wherein the blades extend radiall