초록

A self propelled concrete saw compensates for blade cutting resistance, for example by adjusting a movable drive assembly. An actuator may be used to move the drive assembly, for example through the operation of a control switch by an operator.

대표청구항 ▼

What is claimed is: 1. A concrete saw comprising a frame and a motor on the frame, a cutting blade drive shaft supported on the frame and driven by the motor wherein a cutting blade can be positioned at a front of the saw, first and second front wheels under the motor supporting the frame on a surf

What is claimed is: 1. A concrete saw comprising a frame and a motor on the frame, a cutting blade drive shaft supported on the frame and driven by the motor wherein a cutting blade can be positioned at a front of the saw, first and second front wheels under the motor supporting the frame on a surface to be cut by a cutting blade and configured to raise and lower the front of the saw and a cutting blade relative to the surface, at least one handle supported on the frame at a rear portion of the frame and extending rearward of the frame, a drive assembly for moving the saw in a direction and having first and second powered drive wheels behind the first and second front wheels and rearward of the motor and supporting the frame on the surface, and a powered moving element configured to move the drive assembly about an axis substantially perpendicular to the surface and relative to the frame and to fix the drive assembly in place after being moved by the moving element. 2. The concrete saw of claim 1 wherein the first and second powered drive wheels are on a pivoting support. 3. The concrete saw of claim 1 wherein the powered moving element is a linear actuator. 4. A concrete saw comprising a frame having a front-to-back center line, a motor supported by the frame, a concrete saw blade supported by the frame and driven by the motor wherein the saw blade is positioned away from the center line, at least one powered drive wheel coupled to the frame for supporting the frame on a concrete surface such that the at least one powered drive wheel moves the saw by rotating about a wheel axis extending in a first direction over the concrete surface, and powered moving means for moving the at least one powered drive wheel relative to the frame so that the at least one powered drive wheel rotates with the wheel axis extending in a different direction over the concrete surface without having to loosen any fasteners and for maintaining the at least one powered drive wheel at a new position. 5. The saw of claim 4 wherein the at least one powered drive wheel is supported on an axle and the powered moving means is coupled to the axle. 6. The saw of claim 5 wherein the at least one powered drive wheel includes first and second drive powered wheels mounted to the axle. 7. A concrete saw comprising a frame having a front-to-back center line, a motor supported by the frame, a concrete saw blade supported by the frame and driven by the motor wherein the saw blade is positioned away from the center line, at least one powered drive wheel coupled to the frame for supporting the frame on a concrete surface such that the at least one powered drive wheel moves the saw, and powered moving means for moving the at least one powered drive wheel relative to the frame without having to loosen any fasteners and for maintaining the at least one powered drive wheel at a new position, wherein the at least one powered drive wheel is supported on an axle and the powered moving means is coupled to the axle, wherein the at least one powered drive wheel includes first and second drive wheels mounted to the axle, and wherein the frame is supported on the axle through a single pivot point. 8. The saw of claim 7 wherein the frame is supported on the axle through a pin and bearings. 9. The saw of claim 7 wherein the pivot point is substantially centered between spaced apart sides of the frame. 10. The saw of claim 7 wherein the saw has a center of mass and wherein the pivot point is substantially centered from side to side relative to the center of mass of the saw. 11. The saw of claim 7 wherein the first and second powered drive wheels include respective drive motors. 12. A concrete saw comprising a frame having a front-to-back center line, a motor supported by the frame, a concrete saw blade supported by the frame and driven by the motor wherein the saw blade is positioned away from the center line, at least one powered drive wheel having a wheel axis and the at least one powered drive wheel is coupled to the frame for supporting the frame on a concrete surface such that the at least one powered drive wheel moves the saw, and powered moving means for moving the at least one drive wheel axis through an angle in a plane parallel to the concrete surface without having to loosen any fasteners and wherein the powered moving means includes a linear actuator and wherein the linear actuator is configured to fix the at least one powered drive wheel in place after being moved by the powered moving means. 13. The saw of claim 12 wherein the at least one powered drive wheel is coupled to an axle and wherein the linear actuator is coupled to the axle. 14. The saw of claim 13 wherein the at least one powered drive wheel includes first and second powered drive wheels coupled to the axle. 15. The saw of claim 14 wherein the saw blade and one of the powered drive wheels are on the same side of the saw. 16. A concrete saw comprising a frame supporting a motor and a concrete saw blade, the concrete saw blade being driven by the motor, first and second front wheels behind the saw blade supporting the frame on a surface to be cut by the saw blade and positioned so that the motor extends forward and rearward of the front wheels, first and second powered drive wheels behind the front wheels and rearward of the motor supporting the frame on the surface such that the drive wheels move the saw, handles extending rearward of the motor and of the drive wheels, and a linear actuator configured to move the drive wheels relative to the frame and within a plane parallel to the surface and to fix the drive wheels in their new position in the plane after being moved by the linear actuator from a different position in the plane. 17. The concrete saw of claim 16 wherein the first and second drive wheels support an axle. 18. The concrete saw of claim 17 wherein the axle includes first and second ends and wherein the linear actuator is coupled to one of the first and second ends. 19. The concrete saw of claim 16 further including a manually-operated switch for controlling the linear actuator. 20. The concrete saw of claim 16 wherein the frame is supported on the axle at a point other than the center of the axle. 21. A concrete saw comprising a frame supporting a motor and a concrete saw blade, the concrete saw blade being driven by the motor, first and second front wheels behind the saw blade supporting the frame on a surface to be cut by the saw blade and positioned so that the motor extends forward and rearward of the front wheels, first and second powered drive wheels behind the front wheels and rearward of the motor supporting the frame on the surface such that the drive wheels move the saw, handles extending rearward of the motor and of the drive wheels, and a linear actuator configured to move the drive wheels relative to the frame and to fix the drive wheels in their new position after being moved by the linear actuator, wherein the first and second drive wheels support an axle, and wherein the frame is supported on the axle at a center point of the axle. 22. The concrete saw of claim 21 wherein the axle includes a spindle supporting the frame. 23. A saw comprising a frame supporting a motor and supporting a blade support shaft forward of the motor wherein the blade support shaft is configured to support a blade off center relative to a center of the saw, at least one handle rearward of the motor, front wheels behind the blade support shaft, positioned under the motor such that the motor extends forward and rearward of the front wheels and supporting the frame on a surface wherein the wheels are configured to support the saw so that the wheels roll in a first direction, first and second drive wheels positioned rearward of the motor and configured to be movable relative to the frame so that the drive wheels roll in a second direction different from the first direction and further including a powered actuator configured to move the drive wheels relative to the frame and to fix the drive wheels in their new position after being moved by the powered actuator. 24. The saw of claim 23 wherein the first drive wheel and the second drive wheel are supported by an axle so that the first and second drive wheels can be configured to be movable in the second direction. 25. The saw of claim 24 wherein the powered actuator is a linear actuator linked to the axle. 26. The saw of claim 23 wherein the second drive wheel is movable relative to the frame so that the second drive wheel rolls in a second direction different from the first direction, and wherein the first and second drive wheels are linked so that the first and second drive wheels can roll in the second direction together. 27. The saw of claim 26 wherein the second drive wheel is pivotable about a substantially vertical axis. 28. The saw of claim 26 wherein the first and second drive wheels rotate about a wheel axis and wherein the first and second drive wheels pivot about a pivot axis that substantially intersects the wheel axis. 29. The saw of claim 28 wherein the pivot axis is substantially vertical. 30. The saw of claim 28 wherein each of the first and second drive wheels includes a tread width and wherein each of the first and second drive wheels include a pivot axis and each pivot axis is substantially centered on the respective tread width. 31. The saw of claim 26 further including a tie rod linking the first and second wheels. 32. The saw of claim 26 wherein the first and second drive wheels are mounted to an axle pivotable relative to the frame. 33. The saw of claim 26 wherein the first and second drive wheels pivot about respective substantially vertical axes. 34. The saw of claim 26 wherein the first and second drive wheels have respective front-to-back positions relative to the frame and wherein the front-to-back positions of each of the first and second drive wheels remain substantially constant when the first and second drive wheels are movable in the first direction and when they are movable in the second direction. 35. The saw of claim 26 wherein the first and second drive wheels are substantially aligned with an axis transverse with respect to the saw when the first and second drive wheels are movable in the first direction and when they are movable in the second direction. 36. A method for adjusting the movement of a saw comprising: running a saw blade on the saw, followed by lowering the saw to place the rotating blade into cutting contact with a surface to be cut so that a substantial portion of a weight of the saw is bearing on the blade while the blade is cutting; moving the saw in a first direction so that the saw blade can follow a cutting line and so that first and second drive wheels positioned behind first and second front wheels and to a first side of the saw blade can move in a first direction; moving with a powered actuator the first and second drive wheels to respective second positions so that the first and second drive wheels move in a second direction different than the first direction; and fixing with the powered actuator the first and second drive wheels in the second positions. 37. The method of claim 36 further including moving the first and second drive wheels while the saw is moving. 38. The method of claim 36 wherein moving the first and second wheels includes moving the first and second drive wheels simultaneously. 39. The method of claim 36 wherein moving the first and second drive wheels includes moving the first and second drive wheels separately. 40. The method of claim 36 wherein moving the first and second drive wheels includes moving the first and second drive wheels using a linear actuator. 41. The method of claim 36 wherein the first and second drive wheels are on an axle and wherein moving the first and second drive wheels includes moving the axle. 42. The method of claim 36 wherein the first drive wheel is pivotable about a vertical axis substantially centered on the first drive wheel. 43. The method of claim 42 wherein the second drive wheel is pivotable about a vertical axis substantially centered on the second drive wheel. 44. The method of claim 36 further including moving the first and second drive wheels in predetermined increments. 45. A concrete saw comprising a drive assembly for moving the saw in a direction and having at least one drive element, a frame and a blade supported by the frame, a powered moving element configured for pivoting the drive assembly relative to the frame about a substantially vertical axis and for fixing the drive assembly in place when the powered moving element pivots the drive assembly, a console supported on the frame and configured to allow access to the console by an operator, and an electromechanical control on the console and configured to control the powered moving element. 46. The concrete saw of claim 45 wherein the electromechanical control is a switch. 47. The concrete saw of claim 46 wherein the switch is a toggle switch. 48. The concrete saw of claim 46 wherein the control and the moving element are configured to move the powered moving element in predetermined increments.