Abstract: The invention provides a new and improved diamond saw blade for use in cleaning the joints commonly found between concrete sections or slabs. The diamond cutting blade designed in accordance with the present invention provides a thin metal disk with a plurality of abrasive segments secured to the circumferential edge, the blade being adapted for rotation about an axis of rotation. The segments are symmetrically spaced about portions of the periphery of the disk in close end-to-end alignment with one another. A plurality of large elongated openings or gullets are formed in the disk symmetrically spaced in an annular zone located along the periphery of the blade. The gullets occupy at least 30%, and preferably at lest 40% of the outer periphery or circumference of the blade. With this arrangement, the gullets allow the blade to efficiently remove sealant from the joints of concrete.

Abstract: The present invention provides a hole saw or core drill bit for cutting annular holes in materials such as concrete, asphalt, masonry, rock, stone and related materials. The bit includes an elongated cylindrical body having a first end portion and a second end portion, a mounting platform at the first end of the body for attaching the bit to a driver and a cutting head at the second end of the body. The cutting head constitutes a plurality of cutting segments mounted on the annular face of the second end portion of the body. Each of the segments includes an outer portion, a middle portion and an inner portion. Each of the portions includes diamond particles dispersed throughout. The inner portions and the outer portions of the segments each have a greater concentration of diamond particles as compared to the middle portions. This dispersion of diamond particles provides a core drill bit with improved performance.

Abstract: In a preferred embodiment the core drilling rig of the present invention includes a base, a vertically extending mast, a movable carriage mounted on the mast, an electric powered motor for rotatably driving a core drill bit, and a control system for controlling the supply of electric power to the drive motor. The control system includes a motion sensitive device for detecting the unwanted movement of the base and suspending the supply of electric power to the motor.

Abstract: The present invention provides a new and improved rideable power saw for cutting concrete, asphalt, rock and the like. The saw includes a seat for supporting the rider and a mechanical steering assembly for manipulating the position of a rear drive wheel which is powered by a hydraulic motor. The saw also includes a blade drive mechanism for supporting and rotating the rotary saw blade. The saw blade is powered for rotation by a hydraulic motor and the blade drive mechanism includes a hydraulic cylinder for raising and lowering the position of the cutting blade without altering the position of the main platform of the saw.