Abstract: A core cutter includes a tubular body portion and a plurality of cutting blades arranged at a tip end of the body portion at predetermined intervals in a circumferential direction. At least one cutting blade serves as an inner cutting blade, and the remaining cutting blades serve as outer cutting blades. Through grooves penetrate a tip end of the body portion to open toward a tip end side of the core cutter. Each of the cutting blades having the same circumferential-direction size as the through groove. Gullets are configured to discharge the chips, each of the gullets formed by an outer peripheral surface. The cutting blades are welded to through grooves such that a radially inner end of an axial-direction tip end portion of each of the cutting blades coincides with or substantially coincides with a peripheral surface of an axial-direction tip end portion of the gullet.

Abstract: A coolant supply device attached to an electric drilling tool is configured to supply a coolant to a drilling portion at a distal end of a drill. The coolant supply device includes: a first flange member and a second flange member provided axially on a rotating shaft, the rotating shaft sharing a same axis with the drill, the first flange member being positioned at the drill side, the second flange member being positioned such that the second flange member is more distant from the drill than the first flange member; space formed between the flange members, into which a coolant is injected; a coolant supply passage formed between the first flange member and the drill and guiding the coolant in the space to the drill; and a coolant push-out mechanism configured to push the coolant out of the space toward the coolant supply passage.

Abstract: The object of the invention is to provide a hard tip where the nose side has wear resistance and the bonding side has toughness. The chemical composition of sintered hard alloy constituting the hard tip is such that a compounding ratio of WC to Co is substantially the same from the nose side to the bonding side, and a first bonding metal or a second bonding metal has a gradient chemical composition wherein the content of the first bonding metal or the second bonding metal is increased from the nose side to the bonding side, the first bonding metal does not form the eutectic texture with WC, and the second bonding metal has the eutectic temperature with WC over the eutectic temperature of WC—Co sintered hard alloy and the melting point over the liquid phase sintering temperature of WC—Co sintered hard alloy.

Abstract: An outer peripheral surface of a tip end portion of the core body has a tapered surface which is thinner toward the tip end and is edged at the tip end. Recesses 2B are formed at an opening peripheral edge of the tip end portion to attach cutting chips 3. A portion of the core body 2 which is adjacent to a forward portion of each of the recesses in the rotational direction is bent radially inward. Each of the cutting chips 3 has a stepped portion such that a radially inner portion 3a of a forward end portion protrudes forward and a radially outer portion of the forward end portion recedes rearward. A radially inner portion of a rearward end portion of the stepped portion is located forward and a radially outer portion of the rearward end portion is located rearward.

Abstract: A shank attachment device attaches a core drill to a rotating portion of a drill device and includes an arbor and a shank. The arbor is detachably attachable to the rotating portion. The arbor and the shank are detachably attachable to each other. The shank is detachably attachable to the core drill. A stopper engages a groove of the shank to stop a movement of the shank in an axial direction away from the arbor. A rotational torque of the arbor can be transmitted to the shank by engaging a first engaging portion of the arbor with a first engaged portion of the shank. The shank contacts the arbor to stop the movement of the shank in the axial direction toward the arbor.

Abstract: An object is to provide a drill bit with improved strength of joint between a bit tip and a bit shaft without diminishing dust suction performance of the drill bit. A drill bit 1 includes: a bit tip 3 including at least three cutting edge portions arranged at the distal end of the bit tip 3 such that they are spaced apart from each other in a circumferential direction, each cutting edge portion 3c having a rake face 3s and a relief face 3e forming a joint ridge L1 serving as a cutting edge; and a bit shaft 2 having a distal end face 2F welded to a proximal end face of the bit tip 3 such that the bit shaft 2 rotates integrally with the bit tip 3. The bit shaft 2 includes a dust suction passage 4 extending in the longitudinal direction of the bit shaft 2, such that the distal end of the dust suction passage 4 extends to a distal end portion of the bit shaft.

Abstract: An object is to provide a rotary tool and the like, in which an occurrence of plastic deformation is suppressed even when a great rotational torque is exerted. A rotary tool B includes a cutting part 14 at its distal end portion and a shank 11 at its proximal end portion. The cutting part 14 has cutting edges that are arranged in a manner to face forward, and the shank 11 is to be inserted and attached into an insertion hole 1 of an arbor A. The shank 11 includes: engagement recesses 15 which come into engagement with locking members 2 which are provided in the arbor in such a manner as to be protrudable inwardly from the insertion hole 1; and passage recesses 18 which allow the locking members to be guided into the engagement recesses 15. The rotary tool B is configured such that falling off of the rotary tool B from the arbor A is prevented. A groove 16 is formed in the shank 11 at a portion where an engagement recess 15 is either formed or not formed.

Abstract: A water feed apparatus (20) of the present invention includes a water storage tank (40) that stores water for feeding, a pump unit (50) that feeds gas with a pressure to the water storage tank (40), and an adapter (30) that couples between the water storage tank (40) and a core drill (1). The pump unit (50) has a gripper portion (51) whose internal space is enlargingly and reducingly deformable by a gripping operation by an operator to feed the gas to the water storage tank (40). The adapter (30) has a drill-mounting portion (31b) for mounting on the core drill (1), a tank mounting portion (34) where the water storage tank (40) is mounted, a water passage (37) that connects between the drill-mounting portion (31b) and the tank mounting portion (34), and a valve unit (33) that opens and closes the water passage (37).

Abstract: A shank attachment structure which may supply coolant even if a drill without a center pin is attached. A shank can be attached to a shank attachment hole with a single motion. The outer diameter of the shank can be inserted into the shank attachment hole. A chamfered portion is formed around an edge of a base end, and an elongated concave portion is formed on a tip end. A coolant hole is formed on a base end of the shank attachment hole, and a valve body is disposed in the hole. A sealing member is disposed adjacent to the tip end side. A first sleeve is disposed such that a base of the shank moves the first sleeve, so that a base of the sleeve separates from the sealing member; and when the shank is not in contact with the tip, an outer peripheral surface of the first sleeve moves the engaging member radially outwardly.

Abstract: Object: A drill dust collector is provided that is capable of drilling holes in an area ranging from a position near a corner to a position distant from the corner and that can be positioned with a side face in contact with an upright face such as a wall during drilling. Means for Solving: The drill dust collector has (i) an opening 2C provided in the upper face of a box having an open lower face 1C, for receiving a drill inserted therein; (ii) a suction port 1U connected to the leading end of a suction hose 3 connected to an suction apparatus; and (iii) a contact member 1A of high flexibility formed so as to extend around the lower face of the box. The box has a lid member 3 composed of the opening 2C and its peripheral part, and a box body 1. The lid member 3 is placed so as to be rotatable relative to the box body 1 and the opening 2C is located at a position the center of which is shifted from the center of rotation of the lid member 3 relative to the box body 1.

Abstract: To provide a user-friendly core drill which, when forming a large-diameter cut hole by the core drill with respect to an object to be drilled, such as concrete, is able to easily form, for example, a chamfered portion or a countersunk portion with respect to an opening end portion of the cut hole. In a core drill comprising a base body including a shank and a drill core body including a drill cutting blade, a connection opening portion of the drill core body being attached to the base body, the connection opening portion of the drill core body is provided with a concave portion forming member including a large-diameter hole cutting blade, and the large-diameter hole cutting blade is provided outside the drill cutting blade in a radial direction of the connection opening portion.

Abstract: Provided is a core drill which is capable of drilling a hole and consumes small electric power consumption when the core drill is applied to a codeless type electric drill. A core body 2 is formed to have a small thickness. An outer peripheral surface of a tip end portion of the core body has a tapered surface which is thinner toward the tip end and is edged at the tip end. Recesses 2B are formed at an opening peripheral edge of the tip end portion to attach cutting chips. A portion of the core body which is adjacent to a forward portion of each of the recesses in the rotational direction is bent radially inward. Each of the cutting chips 3 is configured to have a stepped portion when viewed from the bottom such that a radially inner portion 3a of a forward end portion 3 protrudes forward in the rotational direction and a radially outer portion of the forward end portion 3 recedes rearward in the rotational direction.

Abstract: A drill bit comprises a plurality of cutting blades arranged circumferentially, the cutting blades having a cutting edge formed by a connecting ridge line between a cutting face and a flank; and a tip formed by coupling radially inner ends of the cutting edges to each other at a center portion of a bit tip end, wherein at least one of the cutting blades has a first flank and a second flank, wherein the first flank has a blade tip side flank close to the cutting edge and a base end side flank formed on the base end side of the blade tip side flank, and wherein a tilt angle ?1 of the blade tip side flank 3a is smaller than a tilt angle ?2 of the base end side flank 3b which is tilted toward the axial direction.

Abstract: A core cutter includes a body portion 1 and a plurality of cutting blades 2 arranged at intervals in a circumferential direction. At least one of the cutting blades serves as an inner cutting blade, and the remaining cutting blades 2 serve as outer cutting blades. The thickness of the body portion maintains distortion resistance of the body portion. Through grooves penetrating a tip end of the body portion are formed toward a tip end side. The cutting blades are attached to the through grooves 3, and have the same size as the through groove 3. Gallets discharge the chips, with each of the gallets formed by an outer peripheral surface. The cutting blades are welded to the grooves such that a tip end portion coincides with a peripheral surface of an axial-direction tip end of the gallet.

Abstract: A shank attachment device attaches a core drill to a rotating portion of a drill device and includes an arbor and a shank. The arbor is detachably attachable to the rotating portion. The arbor and the shank are detachably attachable to each other. The shank is detachably attachable to the core drill. A stopper engages a groove of the shank to stop a movement of the shank in an axial direction away from the arbor. A rotational torque of the arbor can be transmitted to the shank by engaging a first engaging portion of the arbor with a first engaged portion of the shank. The shank contacts the arbor to stop the movement of the shank in the axial direction toward the arbor.

Abstract: A shank attachment structure which may supply coolant even if a drill without a center pin is attached. A shank can be attached to a shank attachment hole with a single motion. The outer diameter of the shank can be inserted into the shank attachment hole. A chamfered portion is formed around an edge of a base end, and an elongated concave portion is formed on a tip end. A coolant hole is formed on a base end of the shank attachment hole, and a valve body is disposed in the hole. A sealing member is disposed adjacent to the tip end side. A first sleeve is disposed such that a base of the shank moves the first sleeve, so that a base of the sleeve separates from the sealing member; and when the shank is not in contact with the tip, an outer peripheral surface of the first sleeve moves the engaging member radially outwardly.

Abstract: The object of the invention is to provide a hard tip where the nose side has wear resistance and the bonding side has toughness. The chemical composition of sintered hard alloy constituting the hard tip is such that a compounding ratio of WC to Co is substantially the same from the nose side to the bonding side, and a first bonding metal or a second bonding metal has a gradient chemical composition wherein the content of the first bonding metal or the second bonding metal is increased from the nose side to the bonding side, the first bonding metal does not form the eutectic texture with WC, and the second bonding metal has the eutectic temperature with WC over the eutectic temperature of WC—Co sintered hard alloy and the melting point over the liquid phase sintering temperature of WC—Co sintered hard alloy.

Abstract: A core cutter comprises a cylindrical base, a plurality of cutting portions provided at a tip end of the base, discharge grooves configured to discharge chips cut by the cutting portions, and an attaching portion. Each of the cutting portions 2 includes a block and at least three cutting blades. A first cutting blade 2a may be located radially inward relative to the second and third cutting blades 2b and 2c and the second cutting blade 2c is located between the first and third cutting blades in a radial direction, and the cutting blades deviate rearward in a rotational direction. A wall 3b of the discharge groove 3 corresponds to a cutting surface 2k of the third cutting blade, and a gallet 4 is provided adjacent each cutting portion, the gallet formed by cutting an outer peripheral surface of a tip end portion.

Abstract: An anchor bolt hole cleaning device is provided with a brush on a peripheral portion thereof and is capable of cleaning cutting powder adhered to a hole inner peripheral surface. The anchor bolt hole cleaning device includes a suction nozzle which can be inserted into an anchor bolt hole and suctions the cutting powder. The suction nozzle includes a main body that is a tubular body, a suction opening formed at a tip end portion of the main body, and an exhaust opening. The exhaust opening is formed at a base end portion of the main body to be connected to a tip end of a suction hose whose base end is connected to a suction opening of a suction device. The brush is disposed on an outer peripheral surface of the main body.

Abstract: Object: A drill dust collector is provided that is capable of drilling holes in an area ranging from a position near a corner to a position distant from the corner and that can be positioned with a side face in contact with an upright face such as a wall during drilling. Means for Solving: The drill dust collector has (i) an opening 2C provided in the upper face of a box having an open lower face 1C, for receiving a drill inserted therein; (ii) a suction port 1U connected to the leading end of a suction hose 3 connected to an suction apparatus; and (iii) a contact member 1A of high flexibility formed so as to extend around the lower face of the box. The box has a lid member 3 composed of the opening 2C and its peripheral part, and a box body 1. The lid member 3 is placed so as to be rotatable relative to the box body 1 and the opening 2C is located at a position the center of which is shifted from the center of rotation of the lid member 3 relative to the box body 1.