Abstract: A slingshot releaser including a clamp, which stably holds a pouch attached to an elastic band and a pellet. The clamp has two rotatable holding rollers arranged on the distal ends of two arms. Each holding roller 17 has a peripheral surface including a support groove 21 and support rings 22, which are arranged perpendicular to the roller axis. The clamp has a pouch holder defined between the arms to hold the pouch when the clamp is closed. A lever is operated to open the clamp. This flings the pellet out of the clamp with the elastic force of the elastic band as the pouch and the pellet rotate the holding rollers.

Abstract: A cylindrical blade body of a hole cutter includes blades and grooves. Each of the blades is disposed alternately with a corresponding one of the grooves. A cutting edge of each blade includes an outer cutting edge, an inner cutting edge, and a stepped cutting edge. The outer cutting edge of each blade has a point located at a radial outer position of the outer cutting edge. The inner cutting edge of each blade has a point located between the inner cutting edge and the stepped cutting edge. The heights of the points of the inner cutting edges are substantially equal for all blades. The heights of the points of the outer cutting edges are different among the blades. This hole cutter makes it possible to reduce anti-cutting resistance and obtain an optimal cutting state.

Abstract: A tool holder holds a shank of a cutter tool. The tool holder comprises a supporting cylinder. An operation body moves between a locking position and an unlocking position A locking member is supported by the supporting cylinder. The locking member moves radially in accordance with the position of the operation body. An engaging member is located between the supporting cylinder and the operation body. The engaging member moves between an engaging position and a disengaging position. When the engaging member is in the engaging position, the operation body is prevented from moving relative to the supporting cylinder and is held in the unlocking position and when the engaging member is in the disengaging position the operation body is allowed to move relative to the supporting cylinder. This mechanism facilitates smooth insertion of the cutter into the supporting cylinder.

Abstract: A cylindrical blade body of a hole cutter includes blades and grooves. Each of the blades is disposed alternately with a corresponding one of the grooves. A cutting edge of each blade includes an outer cutting edge, an inner cutting edge, and a stepped cutting edge. The outer cutting edge of each blade has a point located at a radial outer position of the outer cutting edge. The inner cutting edge of each blade has a point located between the inner cutting edge and the stepped cutting edge. The heights of the points of the inner cutting edges are substantially equal for all blades. The heights of the points of the outer cutting edges are different among the blades. This hole cutter makes it possible to reduce anti-cutting resistance and obtain an optimal cutting state.

Abstract: A tool holder holds a shank of a cutter tool. The tool holder comprises a supporting cylinder. An operation body moves between a locking positionand an unlocking position A locking member is supported by the supporting cylinder. The locking member moves radially in accordance with the position of the operation body. An engaging member is located between the supporting cylinder and the operation body. The engaging member moves between an engaging positionand a disengaging position When the engaging member is in the engaging position, the operation body is prevented from moving relative to the supporting cylinder and is held in the unlocking position and when the engaging member is in the disengaging position the operation body is allowed to move relative to the supporting cylinder. This mechanism facilitates smooth insertion of the cutter into the supporting cylinder.

Abstract: A cutting apparatus for cutting a rail or other elongated workpiece includes a rotatable blade for cutting the rail, a blade cover for covering the blade, an engine (or motor) for driving the blade, and a frame for supporting the blade, the blade cover and the driver. The cutting apparatus further includes link mechanisms. One link mechanism supports the blade and the blade cover relative to the frame and permits the blade cover to move while maintaining a predetermined attitude during cutting. Therefore, the blade cover moves vertically and avoids hitting obstacles. Another link mechanism moves the driver while maintaining a predetermined attitude of the driver. Therefore, the driver remains level during cutting.

Abstract: A hole cutter having a body provided with first and second types of cutting teeth. The cutter facilitates the discharge of cutting chips during machining of a workpiece. The tooth depth of the left and right sections of each of the second type of teeth is smaller than that of the left and right sections of each of the first type of teeth. The tooth depth of the middle section of each tooth of the second type is greater than that of the middle section of each tooth of the first type. A linear flattening section is provided at the middle portion of a second blade edge of each tooth of the second type. The flattening section causes each cutting chip to be shaped in a strip-like manner when removed from the workpiece. This separates the ends of the cutting chips from each other and prevents the chips from becoming entangled to one another.

Abstract: The apparatus for boring a web of a section. The apparatus is provided with a boring device which is opposed perpendicular to the web of a clamped section and arm plates for supporting the boring device. The apparatus further has a clamping mechanism for clamping the section from each side thereof along the direction substantially parallel to the rotational axis of the boring device.

Abstract: An electrostatic precipitator for removing fine particles from gas is described. The precipitator includes an array of dust collection pipes, each negatively charged and serving as an electrode. Each pipe has a pin-like positively charged discharge electrode centrally located within it. Mist-laden gas is caused to flow through the pipes and is electrostatically cleaned. A slit is formed in the pipes to permit some cleaned gas to be mixed with uncleaned gas and reintroduced into the pipes to reduce the density of the fine particles in the gas entering the pipes. The pipes may be vertically or horizontally arranged.

Abstract: An improved annular hole cutter is disclosed that has a plurality of alternately arranged first and second cutting teeth positioned at substantially equally spaced intervals about the distal end of the cutter body. All of the cutting teeth having angled bottom faces that are tapered at the same angle towards a radially inner side of the bottom faces. The first cutting teeth each have a substantially straight leading edge that includes an active cutting surface and an inactive surface. The second cutting teeth each have circumferentially stepped inner and outer cutting edges. The relative axial heights of the cutting teeth are adjusted so that the active cutting surfaces of the first cutting teeth are formed at the same axial height as their radially corresponding cutting edges of the second cutting teeth. At the same time, the inactive surface of the first cutting teeth are formed at a different axial height than their radially corresponding cutting edges of the second cutting teeth.

Abstract: A drill and trimming attachment assembly is disclosed for drilling holes with beveled top openings in a work piece. The assembly includes a drill shaft with at least one longitudinally extending groove formed therein. A trimming attachment suitable for clamping to the drill shaft is also provided to form a beveled recess at the top of a hole formed by the drill. The trimming attachment includes a body and a trimming blade having base and arm portions. The base portion of the trimming blade is detachably secured to the body, and the body is arranged to be removably journaled about and clamped to the shaft of the drill such that an edge of the arm portion of the trimming blade is closely received by the groove. Thus, during use, the groove carries at least a portion of the load acting against the trimming blade.

Abstract: A design of a drill and a method for using the same are disclosed. A groove is formed on the outer periphery of an adapter which is connected to the electric motor. A fluid supply line is also formed on the adapter so as to lead fluid to the groove. Openings are provided at a proximal end of a shank, adjacent to the groove. Guide flutes extending from the openings to a tip of the shank are formed at an outer periphery of the shank so as to define passages for leading the fluid introduced from the openings to the tip of the shank to be sprayed upon the cutting debris. Exhaust ports for discharging the debris and exhaust passages for leading the debris through the shank to the exhaust ports are provided at the adapter. The guide flutes can be formed with milling machine or the like.When the drill is used, the drill is pressed against a material while being rotated. Then, the fluid is introduced into the passages between the shank and a sleeve and is sprayed upon the cutting debris.

Abstract: A vibration damper for a rotary cutter is disclosed. The rotary cutter has a rotary saw blade and a guard for covering the rotary saw blade. The vibration damper is disposed inside the guard and has a contact member which contacts the rotary saw blade.

Abstract: A method of attaching segments to the body of a cutting tool, such as a diamond saw blade, is initiated by inseparably coupling the segments to their respective interposed members by sintering. The interposed members are made of iron, cobalt, or other metal. Then, the interposed members are rigidly coupled to the body by welding or other method.

Abstract: A hole cutter having a generally cylindrical body provided with a plurality of first and second cutting teeth around its lower end. Each of the first cutting teeth has a bottom surface defining along its front edge at least two cutting edges which are separated from each other by a shoulder having a certain width and extending substantially circumferentially of the cutter body. Each of the second cutting teeth has a bottom surface provided with a ridgeline extending substantially circumferentially of the body and defining two cutting edges along the front edge of the bottom surface of each second cutting tooth. Each of the cutting edges on each of the second cutting teeth is partly located below one of the cutting edges on each first cutting tooth.

Abstract: A hole cutter having a generally cylindrical cutter body provided around its lower end with a plurality of first cutting teeth each having a plurality of cutting edges, and a plurality of second cutting teeth adapted to scrape a surface cut by the first cutting teeth.