US Pat. No. 9,463,507

METHOD FOR PRODUCING HARD TIP

KABUSHIKI KAISHA MIYANAGA...

1. A method for producing a hard tip defining a nose side and a bonding side and comprising a block of a WC—Co sintered hard
alloy and a nickel bonding metal, wherein a compounding ratio of WC to Co in the WC—Co sintered hard alloy is substantially
the same at each layer from a nose layer of the nose side to a bonding layer of the bonding side via at least one intermediate
layer, and a content of the bonding metal increases from the nose side to the bonding side, comprising:
(a) feeding sintered hard alloy powder for the nose layer containing a required compounding ratio of WC to Co and a first
quantity of a bonding metal into a compacting mold for the hard tip,

(b) layering sintered hard alloy powder for at least one intermediate layer comprising a required compounding ratio of WC
to Co and the bonding metal whose content gradually increases compared with the nose layer upon the nose layer in the compacting
mold for the hard tip,

(c) layering sintered hard alloy powder for the bonding layer comprising a required compounding ratio of WC to Co and a second
quantity of the bonding metal upon the intermediate layer(s) in the compacting mold for the hard tip and adding pressure to
obtain a compact, the second quantity being larger than the first quantify, and

(d) putting the compact in a heating furnace and sintering at a temperature at or below the melting point of the bonding metal
and at a pressure lower than atmospheric pressure to produce the hard tip.

US Pat. No. 9,457,491

COOLANT SUPPLY DEVICE AND ELECTRIC DRILL UNIT PROVIDED WITH COOLANT SUPPLY DEVICE

KABUSHIKI KAISHA MIYANAGA...

1. A coolant supply device attached to an electric drilling tool and configured to supply a coolant to a drilling portion
at a distal end of a drill when the drill performs drilling, the coolant supply device comprising:
a first flange member and a second flange member provided 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 along the rotating shaft;

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, the coolant supply passage 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;
wherein the second flange member is configured to be lifted and lowered along the rotating shaft, and
a locking portion is formed in the rotating shaft, the locking portion corresponding to a height position of the second flange
member when the coolant is injected into the space, and

the second flange member is provided with a stopper member configured to be removably locked to the locking portion.

US Pat. No. 9,950,445

HOLE-DRILLING DEVICE FOR DRILLING HOLE WITH EXPANDED DIAMETER HOLE PORTION

KABUSHIKI KAISHA MIYANAGA...

1. A hole-drilling device for drilling a hole with an expanded diameter hole portion, the hole-drilling device comprising:a body including a shank at its rear part;
a sleeve attached to a front part of the body such that the sleeve is movable relative to the body in a front-rear direction over a predetermined range, the sleeve including a contacting portion at its front end, the contacting portion coming into contact with a surface of a drilling object;
a first urging unit that urges the sleeve forward relative to the body;
a drill bit body provided with a drilling bit at its distal end, the drill bit body being configured such that a proximal end portion of the drill bit body is inserted in a bottomed insertion hole formed in the front part of the body, the drill bit body being inserted in and attached to the sleeve such that the drill bit body is movable in the front-rear direction;
an expanded diameter hole portion forming member provided with a cutting bit at its distal end and attached to a side surface of the drill bit body such that the expanded diameter hole portion forming member is movable in the front-rear direction, the cutting bit protruding laterally from the drill bit body when the expanded diameter hole portion forming member moves forward on the side surface of the drill bit body;
a second urging unit that urges the expanded diameter hole portion forming member rearward relative to the drill bit body; and
a cam rotatably supported by the body and provided with contacting portions at both sides with respect to a rotation center, one of the contacting portions being contacted by a predetermined portion of an inner wall of the sleeve, the other contacting portion being contacted by a proximal end portion of the expanded diameter hole portion forming member, wherein
the expanded diameter hole portion forming member is configured to move forward on the side surface of the drill bit body owing to rotation of the cam when the body moves forward relative to the sleeve.

US Pat. No. 10,132,344

ANCHOR BOLT

KABUSHIKI KAISHA MIYANAGA...

1. An anchor bolt to be inserted in a mounting hole formed in a wall surface, the anchor bolt comprising:a shaft elongated and extending along its axis, the shaft including an expanded diameter portion formed on its distal end and a bolt formed on its proximal end, the expanded diameter portion having a tapered outer peripheral surface that expands outwardly when seen in an insertion direction into the mounting hole; and
a hollow sleeve that covers and is in contact with an outer peripheral surface of the shaft, the sleeve including an expandable portion formed at its distal end, the expandable portion being configured to bend outwardly to be in an expanded state, wherein
a state where the sleeve covers the shaft such that the expandable portion is in an unexpanded state is a first state of the shaft and the sleeve,
when the sleeve is further pushed into the mounting hole in the insertion direction from a state where the shaft and the sleeve in the first state are inserted in the mounting hole such that the distal end of the shaft is in contact with a bottom of the mounting hole, the expandable portion bends outwardly along the expanded diameter portion to be in the expanded state,
a first recessed groove is formed in an outer peripheral surface of the sleeve,
a ring that comes into contact with an inner peripheral wall of the mounting hole is fitted in the first recessed groove,
a through-hole that allows the first recessed groove and a hollow portion of the sleeve to be in communication with each other is formed in the sleeve,
a second recessed groove is formed in the outer peripheral surface of the shaft at a position that corresponds to a position of the through-hole in the first state,
a fitting piece is formed on the ring, the fitting piece extending such that the fitting piece passes through the through-hole to reach the second recessed groove in the first state, and
the fitting piece serves as a connector that connects the shaft and the sleeve in the first state.

US Pat. No. 9,925,691

DRILL BIT

KABUSHIKI KAISHA MIYANAGA...

1. A drill bit comprising:a pointed head including a plurality of cutting edges, which are arranged in a radial manner with respect to a central axis;
a bit shaft provided with the pointed head at its distal end;
a dust suction passage formed in the bit shaft and extending in an axial direction; and
a hole with an opening, the hole being formed in the pointed head or in a portion of the bit shaft, the portion being near the distal end of the bit shaft, wherein:
the hole is in communication with the dust suction passage;
the bit shaft includes a first portion, the first portion including a core and a rib;
the core extends in the axial direction, and is thinner than the pointed head;
the rib protrudes radially outward from a side surface of the core, and extends over an entire length of the first portion;
wherein the dust suction passage extends through the core in the axial direction; and
wherein the rib includes an expanding portion at its radially outer end portion, the expanding portion expanding in a circumferential direction.

US Pat. No. 10,335,980

DUST SUCTION DRILL AND DUST SUCTION UNIT

KABUSHIKI KAISHA MIYANAGA...

1. A dust suction drill comprising:a drill tip with cutting edge portions formed on a distal end of the drill tip;
a shaft joined to the drill tip and configured to rotate about an axis line; and
a dust suction passage for sucking dust that is generated when the cutting edge portions rotate, the dust suction passage being formed inside the shaft, wherein
the dust suction passage is formed extending substantially parallel to the axis line;
the cutting edge portions and the drill tip are made of a metal and integrally formed together,
the cutting edge portions are provided on a distal end surface of the drill tip and spaced apart from each other in a circumferential direction,
cutting edges, each of which is formed by a joint ridge between a rake face and a relief face of a corresponding one of the cutting edge portions, are arranged radially, and at a center of the drill tip, form a chisel point, which is a pointed end, and
a dust suction hole, which communicates with the dust suction passage, is formed in the rake face or the relief face closely to the chisel point, or formed over the joint ridge between the rake face and the relief face closely to the chisel point; and further including
an auxiliary passage, which communicates with the dust suction passage and in which a removal member for pushing dust out of the dust suction passage is insertable, is formed in the shaft; and
an auxiliary passage closing cover that is attached to the shaft, the auxiliary passage closing cover being configured to rotate about the axis line and switch a state of the auxiliary passage between a closed state and an open state by rotating about the axis line.