Abstract: A liquid pump is provided in which pulsations can be properly absorbed even if the pump is driven at a high frequency. A pulsation absorbing unit for absorbing pulsation includes a pulsation absorbing housing disposed on a pump housing member, a second diaphragm attached to the pulsation absorbing housing member and defining a pulsation absorbing chamber communicating with a liquid outlet passage of a liquid pump unit, and a disc spring for biasing the second diaphragm toward the pulsation absorbing chamber.

Abstract: A pump using a piezoelectric diaphragm is designed to allow the diaphragm to be supported appropriately and accurately and to facilitate assembly of housing members. The peripheral edge of a sheet metal of a unimorph diaphragm 40 on the side thereof facing a first housing member 14 is pressed and supported with the ridge of an annular projection 52 annularly provided along the peripheral edge of a vent chamber 38. The first to third housing members 14, 16 and 30 are stacked on one another, and the first and third housing members 14 and 30 are welded together by ultrasonic welding such that the first and second housing members 14 and 16 abut against each other at abutting portions 66 and 68 and the second and third housing members 16 and 30 abut against each other at abutting portions 70 and 72, thereby definitely determining the positional relationship between the housing members.

Abstract: An electromagnetic reciprocating fluid device in which a movable member is equipped with permanent magnets, resists a torque rotating the movable member about an axis thereof in the reciprocating direction. The electromagnetic reciprocating fluid device has a pair of electromagnets facing each other, and permanent magnets disposed in a space between the opposed electromagnets and held by a movable member. When an alternating current is applied to coils formed in the electromagnets, a magnetic force is generated between the electromagnets and the permanent magnets, whereby a driving force for reciprocation is applied to the movable member. One end of the movable member is connected to a piston of a first piston-cylinder assembly, while the other end is connected to a piston of a second piston-cylinder assembly.

Abstract: A magnetic armature is attracted and driven by a magnetic force which is intermittently generated between magnetic poles, and a piston reciprocated by being pushed back by a coil spring is not rotated by the coil spring. When the magnetic armature (28) as attracted between the magnetic pole members (10,12) by the magnetic force comes to a predetermined rotational angle position about the axis, the armature receives a rotational torque that is derived from the magnetic force and acts in a direction opposite to that of the rotational torque applied by a coil spring (30), thereby preventing the armature from being rotated in the predetermined direction. More specifically, the armature (28) has a circular cross-section as a whole and has a chamfered part (28?) parallel to the axis. When the chamfered part enters between the magnetic pole members, the armature receives a rotational torque that is derived from the magnetic force.

Abstract: A drilling device prevents recurrence of an overload condition after occurrence of the overload condition, thereby improving operability and safety in the drilling device. A motor for rotating a drill is connected to an AC power source through a motor control unit, a current detector, and a power switch. A magnet is also connected to the AC power source through the power switch and a full-wave rectifier. The motor control unit rotationally drives the motor on the basis of a signal sent from a main control unit according to a state in which a motor start switch is on. The main control unit controls the motor control unit to gradually reduce a supply voltage to the motor when the motor becomes overloaded, to gradually increase the voltage to the normal power supply condition when the overload condition is vanished, and to stop power supply to the motor if the overload condition continues for a predetermined period.

Abstract: An electromagnetic reciprocating fluid apparatus includes a magnetic circuit device in which magnetic pole members project inward from an annular magnetic circuit member so as to oppose each other. The magnetic pole members and the annular magnetic circuit member have a uniform thickness. First and second additional annular magnetic circuit members are set on both sides of the annular magnetic circuit member to constitute a part of the magnetic circuit device, thereby minimizing the increase in magnetic reluctance due to magnetic flux concentration at the joints between the magnetic pole members and the annular magnetic circuit member.

Abstract: A coupling according to the present invention has a socket (2) and a plug (30) that is inserted into and connected to the socket. The socket includes a socket body (10) having a first through-hole (13b) for a plug-locking element (12b) and an elongated second through-hole (13a) for a sleeve-actuating element (50), and a sleeve (50) set around the socket body. The sleeve is urged by a spring member (15) toward a position for pressing the plug-locking element (12b) against a locking recess (34) of the plug to prevent the plug from slipping out of the socket. The sleeve has a locking surface (50b) that presses the plug-locking element in the position described above. When being inserted into the socket, the plug engages with the sleeve-actuating element to move the sleeve rearward, thereby disengaging the locking surface from the plug-locking element.

Abstract: At least one coupling member (2) has a slide valve holder (42) that is pushed in by the other coupling member (3) when coupled to the coupling member (2). The coupling member (2) further has a rotary valve (41) rotatably supported by the slide valve holder. The slide valve holder has a through-hole (425) constituting a flow path. A valve seat (26) is provided around the through-hole. The rotary valve (41) has an outer peripheral surface portion that slidingly engages the valve seat. One end of a fluid passage (411) extending through the rotary valve is open on the outer peripheral surface portion. The rotary valve is displaceable toward the valve seat and is urged toward the valve seat by a spring member (64). Thus, the outer peripheral surface portion is pressed against the valve seat. When a fluid pressure acts in the coupling member (2) when the coupling members (2, 3) are not coupled to each other, the fluid pressure presses the rotary valve toward the valve seat.

Abstract: A pipe coupling member has a tubular body (20) and a valve unit (22) slidably set in the through-hole of the tubular body. The valve unit has a valve holder (26) and a rotary valve member (30) supported by the valve holder so as to be rotatable about a pivot axis perpendicular to the axis of the through-hole. The valve holder comprises a valve seat portion (26-1) and a valve support portion (26-2) that are separately disposed in series in the axial direction or the direction of the axis of the though hole. The valve support portion rotatably supports the rotary valve member. When the valve holder moves axially in the through-hole, the rotary valve member is rotated by a cam mechanism (32) and displaced between a closed rotational position and an open rotational position while its spherical outer peripheral surface sliding relative to an annular valve seat of the valve seat portion.

Abstract: A rotary cutting machine 10 has a machine body 14 and an arbor 18. The arbor 18 includes a proximal rotary shaft 22 mounted to the machine body 14 for rotation, an intermediate rotary shaft 24 telescopically connected to the proximal rotary shaft via a splined connection, and a distal rotary shaft 26 telescopically connected to the intermediate rotary shaft 24 via a splined connection. A cutting tool C secured to the arbor 18 is extended and retracted via a feed mechanism 20 including first, second, and third racks 30, 31, and 32, and first and second pinions 33, 34.

Abstract: A valve holding member made of a sheet metal includes a hub part (33) having a guide hole (34) through which a valve stem (23) and a plurality of arm parts (32) formed at the peripheral edge of the hub part. The arm parts are extend from the peripheral edge in an axial direction and in a radially outward direction with respect to the axis of the valve stem. The valve holding member also includes any one of a first reinforcing protrusion (35) formed in at least one of the arm parts which extends along a longitudinal direction of the at least one arm part and protrudes radially outward or inward with respect to the axis of the valve stem, a tubular reinforcing part (35c, 35e) formed around the guide hole and extending from the hub part in the axial direction, and a second reinforcing protrusion (35b) formed in the hub part and protruding in the axial direction.

Abstract: There is provided a polishing tool which enables a polishing surface thereof to be in surface contact with a to-be-polished surface over a wide area of the polishing surface when polishing a corner portion, and which can reduce an impact of a polishing member caused when the polishing member hits against a member around the polishing member. A generally triangular polishing member having apex angles of 60 degrees is connected, through the intermediary of an oscillation transmitting member made of a plate-like spring member, to an oscillating shaft oscillated by a motor. The oscillation transmitting member has a triangular base having at the center thereof a fixing hole by which the triangular base is fitted and fixed to the oscillating shaft, and triangular polishing member holding portions each extending from each side of the triangular base. The polishing member has three polishing pieces each composed of a pad held by the polishing member holding portion and a polishing sheet laminated to the pad.

Abstract: A coupling member is provided that comprises a valve movable between a closed position and an opening position. The valve is provided with a seal ring fixed in an annular groove formed in the valve and urged against a valve seat in the closed position. The groove has a forward annular groove portion and a rear annular groove portion shallower than the forward annular groove portion. The seal ring has forward and rear annular seal portions fitted in the forward and rear annular groove portions, respectively. The rear ring portion has substantially the same diameter as the forward seal portion.

Abstract: The invention of this application provides a pneumatic tool with a simple structure. The tool has a tubular housing, a stationary shaft, a first piston slidable along the stationary shaft, a second piston, a tool attachment member drivingly connected to the second piston, a compressed air supply path extending through the stationary shaft to supply compressed air between the first and second pistons, and an air discharge path for discharging the compressed air supplied between the first and second pistons to the outside of the housing when the first and second pistons are separated by a predetermined distance. The compressed air supply path has an axial portion in the stationary shaft and a radial portion, a compressed air inlet recess in the inner wall surface of a shaft sliding hole, and a supply outlet extending forward from the forward end of the compressed air inlet recess and communicating with a portion between the first and second pistons.

Abstract: A male coupling member is provided that is selectively couplable to a first female coupling member (for 25 MPa, for example) and a second female coupling member (for 90 MPa), which handle different fluid pressures. When the male coupling member is coupled to the first female coupling member, a second O-ring that is provided for the second female coupling member is prevented from being displaced by the fluid supplied from the first female coupling member.

Abstract: A coupling has a socket and a plug that is inserted into and connected to the socket. The socket has a locking element and a sleeve actuating element that are radially displaceable to lock the plug as inserted into the socket. A sleeve is provided over the outer peripheral surface of the socket. The inner peripheral surface of the sleeve has a locking surface that presses the locking element from the radially outer side into a lock position. Further, the inner peripheral surface of the sleeve has an inclined surface extending in the circumferential direction thereof. As the plug is progressively inserted into the socket, the sleeve actuating element is pushed radially outward by the plug while engaging the inclined surface, causing the sleeve to be displaced in the circumferential direction. Thus, the inclined surface radially aligns with the locking element, and the locking element is pushed radially outward while engaging the inclined surface by the plug inserted progressively.

Abstract: The diameter of a front end opening section (20-1) extending rearward over a predetermined length from a front end opening of a male member reception hole (20) is larger than a diameter of a male member reception section (20-2) of the male member reception hole that follows the front end opening section. The backup ring (18) is allowed to engage an inner wall surface (20-3) of a front end opening section (20-1) as a backup ring (18) is pressed radially outward from an annular groove (24) by a seal ring (16) that is deformed by engagement with the inner wall surface of the male member reception hole (20) when a male coupling member (12) begins to be inserted into the male member reception hole (20), which prevents the backup ring (18) from coming out, in a radially outward manner, from the annular groove (24).

Abstract: An object of the present invention is to provide an electric screwdriver device having a function for determining that a correct tightening operation has been carried out when the tightening operation has taken a time longer than a reference time predetermined for the tightening operation, characterized in comprising a novel feature for determining the reference time.

Abstract: A pipe coupling member has a tubular body (20) and a valve unit (22) slidably set in the through-hole of the tubular body. The valve unit has a valve holder (26) and a rotary valve member (30) supported by the valve holder so as to be rotatable about a pivot axis perpendicular to the axis of the through-hole. The valve holder comprises a valve seat portion (26-1) and a valve support portion (26-2) that are separately disposed in series in the axial direction or the direction of the axis of the though hole. The valve support portion rotatably supports the rotary valve member. When the valve holder moves axially in the through-hole, the rotary valve member is rotated by a cam mechanism (32) and displaced between a closed rotational position and an open rotational position while its spherical outer peripheral surface sliding relative to an annular valve seat of the valve seat portion.

Abstract: A female coupling member of a pipe coupling is provided which has a fluid passage and a vale therein. The fluid passage is separated by the valve into a first-end side adapted to be connected to a conduit and a second-end side adapted to be connected to a male coupling member. The valve is moveable between an open position for permitting a fluid to flow between the first-end side and the second-end side, and a closed position for blocking the flow of fluid. The valve is provided with a purge flow path that allows the second end side of the fluid passage to communicate with the outside when the valve is in the closed position, and that blocks the communication between the fluid passage and the outside when the valve is in the open position. Thus, the present invention simplifies the purge mechanism of the female coupling member which releases the fluid pressure remaining within the fluid passage when the valve is in the closed position.