Abstract: There is disclosed an article which is formed of a solid-phase or liquid-phase sintered product of a metal powder, ceramic powder or glass powder. For manufacturing the article, an extrudable mixture which contains the material powder and a thermoplastic binder is shaped into a continuous filament suitable for use in fused filament 3D printers. The printed object is then invested in plaster or other castable refractory. The invested object is then subjected to heating. The heating process burns off the thermoplastic binder and sinters the powders of metal, glass or ceramic, leaving a pure metal, glass or ceramic object. The extrudable mixture is produced by preparing a material powder, preparing a binder, then blending the material powder and the binder together. The extrudable mixture is then extruded into a continuous filament suitable for use in various 3d printing hardware.

Abstract: A three-dimensional forming apparatus includes: a stage; a material supply mechanism that supplies a sintered material in which metal powder and a binder are kneaded to a stage; a drying mechanism that dries the sintered material supplied from the material supply mechanism to the stage to form a dry sintered material; an energy radiation mechanism that supplies energy capable of sintering the dry sintered material; and a driving mechanism that is able to three-dimensionally move the material supply mechanism, the drying mechanism, and the energy radiation mechanism relative to the stage. The material supply mechanism includes a material ejection unit supplying a predetermined amount of the sintered material in a gravity direction. The energy radiation mechanism includes an energy radiation unit outputting the energy. The material ejection unit and the energy radiation unit are held in one holding mechanism.

Abstract: Aspects of the disclosure include a removable support for additive manufacture and methods and code for manufacturing and removing the same. A removable support for a laser-sintered component having at least one surface to connect to may include a support body, a first set of connectors, and a second set of connectors. The support body may have a first wing and a second wing, each with a distal surface and a lateral midline bisecting the distal surface. Each set of connectors may project from the distal surface on one side of the lateral midline of their respective wings to connect to the surface of the component while the distal surface also defines a connector-free portion on the other side of the lateral midline.

Abstract: According to the present invention, a lamination molding apparatus configured to mold a desired lamination molded object based on a project file, comprising: a chamber covering a molding region and being filled with an inert gas; a laser beam emitter configured to irradiate material powder with a laser beam for sintering the material powder, in an irradiation region on a material powder layer formed on a molding region, a cutting machine configured to move a cutting tool, within the chamber, for cutting a predetermined cutting allowance from a sintered layer obtained by sintering the material powder a calculation means configured to calculate an amount of displacement between a target irradiation position and an actual irradiation position of the laser beam, and to determine a recommended value of a size of the cutting allowance based on a time transition of the amount of displacement or to generate a new project file containing a size of the cutting allowance set based on a time transition of the amount of d

Abstract: An additively manufactured alloy component has a first portion formed of the alloy and having a first grain size, and a second portion formed of the alloy and having a second grain size smaller than the first grain size. In an embodiment, the alloy component is an alloy turbine disk, the first portion is a rim region of the alloy turbine disk, and the second portion is a hub region of the alloy turbine disk. The first and second grain sizes may be achieved by controllably varying the laser power and/or scan speed during additive manufacturing.

Abstract: One embodiment includes a powder spheroidizing method. The method includes loading a powder into a fluidized bed assembly, fluidizing at least some of the powder in the fluidized bed assembly using an inert gas, and heating the powder while fluidized in the fluidized bed assembly.

Abstract: After preparing a silver-coated copper powder wherein the surface of a copper powder having an average particle diameter of 0.1 to 100 ?m is coated with silver, the silver-coated copper powder is sprayed into the tail flame region of a thermal plasma to cause silver on the surface of the copper powder to diffuse in the grain boundaries of copper on the inside of the copper powder, and thereafter, the surface of the copper powder is coated with silver to produce a metal composite powder wherein the percentage of the area occupied by silver on a cross section of the metal composite powder is 3 to 20% and wherein the surface thereof is coated with silver.

Abstract: A pipe end machining device configured to machine an end of a pipe includes an outer housing having a spindle rotatably mounted therein, tool carriers are mounted on the spindle, a hub assembly attached to the outer housing, a vertical adjustment assembly attached to the hub assembly and to the outer housing, and a drive assembly configured to rotate the spindle and tool carriers. The vertical adjustment assembly adjusts the upward and downward position of the cutting tools relative to the pipe. The hub assembly mounts the device to the pipe and fixes the relative upward or downward position of the cutting tools relative to the pipe, thereby preventing vibration and chatter when the device is cutting a planar surface on the end of the pipe.

Abstract: A tool holder is provided comprising a base body for coupling with a drive spindle that can be driven rotatingly, whereon a clamping chuck for clamping a tool is provided, further comprising a damping element arranged between the base body and the clamping chuck, wherein the damping element is made of an elastomeric material or of a shape memory alloy, and wherein the clamping chuck is solely connected to the base body by means of the damping element.

Abstract: A drilling chuck for operation on an impact drilling spindle, which can be subjected to tangential loading, with a chuck body, which is connected or connectable to the impact drilling spindle in which jaw guides are formed, which run inclined to the chuck axis in which jaw guides and clamping jaws are guided, which can be adjusted by a threaded ring, with a clamping sleeve, which can be coupled in a torque-transmitting manner to the threaded ring, and with a locking device, which is adjustable between a release configuration, which enables a relative rotation of the threaded ring with respect to the chuck body and a locking configuration, which obstructs or prevents this relative rotation. The locking device is formed from a locking sleeve, which is mounted essentially rotationally fixed but axially displaceable with respect to the chuck body, which comprises at least one locking member.

Abstract: A chuck for a power tool includes a chuck body extending along a longitudinal axis. The chuck also includes a plurality of jaws, each with a jaw end, and each movable along a respective jaw axis between a closed position and an open position. Each respective jaw axis is oriented at an oblique angle relative to the longitudinal axis. A biasing member is coupled to the jaws and is operable to bias the jaws toward the closed position. The biasing member includes a spring. The chuck also includes a rotating assembly selectively engageable with the jaws such that, when engaged, the jaws are movable in response to rotation of the rotating assembly. The biasing member includes a guide sleeve coupled to each of the jaws and movable axially along the longitudinal axis in response to each of the jaws moving along its respective jaw axis.

Abstract: A self-adjusting pocket hole jig includes a base having a clamp end and a toggle end, a guide carried by the base and reciprocally movable between a raised position and a lowered position. A clamp assembly is carried by the base and reciprocally movable between an engaged position and a disengaged position. An adjustment mechanism is coupled between the guide and the clamp assembly. The adjustment mechanism is arranged to move the clamp assembly in a forward direction to the engaged position and correspondingly move the guide in a downward direction to the lowered position, and arranged to move the clamp assembly in a rearward direction to the disengaged position and correspondingly move the guide in an upward direction to the raised position.

Abstract: The present invention provides an arbor damping device, including a rod body, a damper, two flexible absorbers and at least one flexible damping adjusting member. The rod body has an internal chamber, and the internal chamber includes a circumferential wall and two end walls. The damper is received in the internal chamber. The damper includes a side surface opposite to the circumferential wall and two end surfaces respectively opposite to the two end walls. The two flexible absorbers are disposed between the two end walls and the two end surfaces respectively. The at least one flexible damping adjusting member is radially disposed between the circumferential wall and the side surface, and axially disposed between the end walls and the two flexible absorbers.

Abstract: A rotary cutting tool having an axis of rotation, a shank area, and a cutting area. The rotary tool has chip flutes reaching as far as a core profile in the cutting area. In order to reduce vibrations of the rotary cutting tool and therefore to permit precise machining and high surface quality with long service lives, the center line of the core profile has a course that deviates from the axis of rotation of the rotary cutting tool and/or the core profile contains mutually alternating sections with increasing cross-sectional area and sections with decreasing cross-sectional area over the length of the cutting area.

Abstract: A cutting tool to cut a hollow vessel includes a conical member, a plurality of grooves, and a plurality of cutting members. The plurality of grooves are disposed in a semi-helix around an outer conical surface of the conical member. Each of the plurality of cutting members is disposed in fixed position within one of the plurality of grooves at a non-zero angle relative to a vertical axis.

Abstract: A pipe milling machine for separating and/or cutting a pipe to length includes a drive unit configured to generate a feed force to the pipe and a holding device configured to hold the pipe. The holding device is mountable around the pipe, the drive unit engages in or touches down on the holding device, the feed force is transferred to the holding device in a location, which contacts the pipe or which is adjacent to a location which contacts the pipe, and/or the drive unit is guided by the holding device.

Abstract: Provided are a porous media bearing for a band saw, a band saw for cutting cant and a method of cutting cant using the band saw. The band saw has a continuous loop blade supported by a drive wheel and first and second support arms having porous media bearings. A location of a blade cutting section, an angle of the blade in relation to the cant being cut, and tension on the blade can be adjusted by moving the first and second support arms.

Abstract: A chainsaw includes a housing, a prime mover, a transmitting member and a bias assembly. The prime mover is mounted to the housing. The saw chain is driven by the prime mover. The guide bar guides the saw chain and the guide bar is slidably connected to the housing. The driving member drives the guide bar to slide relative to the housing. The operating member swings forth and back relative to the housing. The transmitting member enables the driving member to rotate synchronously with the operating member when the operating member is swung forth and enables the operating member to rotate relative to the driving member when the operating member is swung back. The bias assembly biases the transmitting member to engage with the operating member when the operating member is swung forth.

Abstract: This sectional hob is provided with: a cylindrical hob body; a plate-shaped blade having a saw-toothed cutting edge, the blade being disposed in at least one attachment seat formed in an outer peripheral part of the hob body such that a direction of the cutting edge is parallel to a center axis direction of the hob body; and a plurality of wedge members configured to detachably-fix the blade disposed in the attachment seat to the hob body, the wedge members being installed in a recess formed on the outer peripheral part of the hob body, wherein the recess is adjacent to the attachment seat in a circumferential direction of the hob body, and the plurality of the wedge members are disposed in a line in the center axis direction in the recess.

Abstract: A wire electric discharge machine with tension monitoring function comprising a tension generation unit configured to generate tension in the wire electrode, a first tension measurement unit set on the wire electrode and configured to measure tension, and a tension control unit configured to feedback tension value measured by the first tension measurement unit and output tension command value to the tension generation unit such that the tension value is equal to a target value, wherein a warning signal is configured to be generated when the tension command value output by the tension control unit is not within a set range corresponding to the target value of the tension.

Abstract: An electrode for electrical discharge machining which makes it possible to form slits of a honeycomb structure forming die so that a slit width on a front surface side is smaller than a slit width on a back hole side is provided. The electrode for electrical discharge machining includes: plural plate-shaped discharge portions with a thickness that is gradually increased toward tips thereof; and a plate-shaped support portion to which end portions of the plural discharge portions on a side opposite to the tips are connected, wherein a difference between a thickness of the tip; and a thickness of the end portion on the side opposite to the tip ranges from 5 ?m to 500 ?m in the discharge portion.

Abstract: A control device includes: a control unit configured to control a main processing machine by replacing a machining shape on a machining surface of a workpiece specified in a program with a shape corresponding to an enlargement/reduction ratio and replacing a fixing distance for a core specified in the program with a distance corresponding to the enlargement/reduction ratio for the machining shape of the workpiece and a plate thickness ratio between the workpieces.

Abstract: Methods and Apparatuses related to an ergonomic handle are disclosed. An example apparatus for supporting an elongate tool having a barrel may include an ergonomic handle housing. At least a portion of an exterior profile of the ergonomic handle housing includes one or more depressions spatially arranged in series along the portion of the exterior profile of the ergonomic handle housing. The apparatus may also include an attachment device coupled to the ergonomic handle housing and configured to couple the barrel of the elongate tool to the ergonomic handle housing.

Abstract: A welding tape for thermally connecting metal workpieces by fusion, wherein the welding tape in a cross section has an outwardly closing cover layer which comprises an inner cover layer and an outer cover layer, wherein in the transverse direction provision is made at least in side edge regions of the inner cover layer for adhesive layers by means of which the welding tape can be fastened to the workpieces to be connected, wherein in the interior of the cover layer provision is made for a self-combusting exothermic substance, which during ignition provides the thermal energy which is required for the welding, wherein a non-combustible heat shield is arranged exclusively between the exothermic substance and the outer cover layer, and wherein a welding additive is provided between the exothermic substance and the inner cover layer.

Abstract: A method of and system for controlling high frequency arc initiation in a power supply is provided. The power supply includes an output circuit that outputs at least one of a voltage waveform and a current waveform. High frequency, high voltage pulses are induced across a gap between an electrode and a workpiece to create an arc. The method and system further include monitoring at least one of a voltage reading and a current reading across the gap to determine a condition of the arc and controlling the high frequency, high voltage pulses based on the condition of the arc and the type of process, which can be, e.g., SMAW, GTAW, GMAW, FCAW, etc.

Abstract: An arc welding power supply supplies power to a welding wire functioning as a discharge electrode to generate an arc from an electrode distal end of the welding wire and perform arc welding on a welded article. The arc welding power supply includes an output control unit that adjusts the power supplied to the welding wire to a power value suitable for arc welding. A feed control unit cyclically changes a feeding speed of the welding wire. The feeding speed includes a forward feeding speed and a rearward feeding speed. An amplitude control unit cyclically changes an amplitude of the feeding speed of the welding wire to cyclically vary an average arc length.

Abstract: A hand tool for welding-torch maintenance, which can remove sputter adhering to a nozzle with sufficient working efficiency. The hand tool has a pair of metal stays turnably supported by a pivoting axis. The metal stays comprises grips handled by a user, 1st pinchings used for pulling a welding-wire, and 2nd pinchings used for removing sputter adhering to the nozzle. The 1st pinchings are configured so as to be inserted into the nozzle when the metal stays are closed. The 2nd pinchings have projections which are extended outside from the backs of the 1st pinchings and thrown out towards heads of the 1st pinchings. The sputter adhering to the inner-and-outer circumferential surfaces and end face of the nozzle are removed by inserting the 1st pinchings into the nozzle, inserting the end of the nozzle between the 2nd pinchings and the 1st pinchings, and moving the tool to scratch the sputter off the inner-and-outer circumferential surfaces and the end face of the nozzle.

Abstract: Methods and systems for no-glue pocketed spring unit construction. Rows of pocketed springs, preferably arranged into modules of more than two pocketed springs surrounding a central hole, are ultrasonically welded together when paired vibrating probes and anvils press layers of pocketed spring fabric from the rows of pocketed springs together and a welding pulse is transmitted to the vibrating probe.

Abstract: A method of resistance spot welding a workpiece stack-up that includes a steel workpieces and an aluminum alloy workpiece that overlie and contact one another to establish a faying interface at a weld site is disclosed. The method comprises passing a DC electrical current through the workpiece stack-up at the weld site and causing the current to assume a conical flow pattern. The conical flow pattern has a path of current flow that expands along a direction leading from a first welding electrode in electrical communication with the steel workpiece towards a second welding electrode in electrical communication with the aluminum alloy workpiece.

Abstract: A method for shaping a ceramic matrix composite (CMC) sheet having a first surface and a second surface is presented. The method includes receiving an input signal representative of a predetermined shape and a type of the CMC sheet. Further, the method includes selecting a laser beam based on the received input signal. Also, the method includes projecting the selected laser beam on the CMC sheet to shape the CMC sheet into the predetermined shape.

Abstract: An apparatus, system and method for the processing of orifices in materials by laser filamentation that utilizes an optical configuration that focuses the incident laser light beam in a distributed manner along the longitudinal beam axis. This distributed focusing method enables the formation of filaments over distances, and the laser and focusing parameters are adjusted to determine the filament propagation and termination points so as to develop a single/double end stopped orifice, or a through orifice. Selected transparent substrates from a stacked or nested configuration may have orifices formed therein/therethrough without affecting the adjacent substrate. These distributed focusing methods support the formation filaments with lengths well beyond ten millimeters in borosilicate glass and similar brittle materials and semiconductors.

Abstract: A system for additive manufacturing uses a pulsed laser beam with one or more low flux components on the order of kW/cm2, and one or more high flux components on the order of MW/cm2 during the duration of the pulse. The pulsed laser beam is directed onto the powder particles on the substrate thereby melting the powder particles and melting the substrate at the interface layer between the powder and the substrate such that the powder particles bond to the substrate. This is accomplished by using low power (and low cost) lasers to do the majority of the energy transfer, and using high power (and higher cost) lasers to complete the melting process, overcoming the kinetics of powder agglomeration through surface tension forces by partially melting the powder-substrate interface layer before surface tension can take effect on the molten powder particles.

Abstract: A laser processing robot system and a laser processing method, by which the motion accuracy of a robot in the system can be improved and laser processing with high accuracy can be carried out. The robot system is configured to: execute a first robot motion for moving an laser irradiation device to a predetermined command position; measure an actual three-dimensional position of the irradiation device in the first robot motion; calculate a deviation between the command position and the measured actual three-dimensional position of the irradiation device in the first robot motion; store the calculated deviation as a time series of deviation data; and execute a second robot motion in which a robot motion similar to the first robot motion is executed while correcting the laser irradiation position so that the laser irradiation position coincides with a desired position, based on the stored deviation data.

Abstract: An assembly and method of reducing discoloration of a foam material resulting from laser processing the material comprising an assembly configured for positioning below the material being processed and for directing air into open cells of the open-cell foam material to pressurize the material during laser processing. The assembly comprises an air delivery mechanism comprising one or more apertures for an air chamber positioned directly below the material travel path. Aligning the one or more apertures with the axis of the laser beam and its focal point when the material is positioned above the one or more apertures and pressurizing or filling of the open cells with air in the direct vicinity of the target area reduces processing related discoloration of the material. The cells are laser processed concurrently with pressurization thereby substantially reducing settling of debris and smoke on the material and reducing discoloration.

Abstract: An induction heating coil includes a coil section configured to heat a treatment target by induction, a power supply section configured to supply power to the coil section, and a cooling medium passage that is arranged in the power supply section and the coil section, and is configured to supply a cooling medium to the coil section. The coil section, the power supply section, and the cooling medium passage are formed using a metal additive fabrication method.

Abstract: A pulse width controller for a thermal processing system is disclosed. Pulsed electromagnetic radiation is directed through a rotatable wave plate to a polarizing beam splitter, which reflects and transmits according to the phase angle of the wave plate. Radiation transmitted by the polarizing beam splitter is directed into an optical circuit that returns the radiation to the polarizing beam splitter after a transit time. A second rotatable wave plate is positioned in the optical circuit. The polarizing beam splitter reflects and transmits the returned radiation according to the phase angle of the second rotatable wave plate. A second pulse width controller may be nested in the optical circuit, and any number of pulse width controllers may be nested.

Abstract: In a method for machining a workpiece by a pulsed laser beam emanating from a tool head, the pulsed laser beam is guided across the workpiece surface in a constant relative position between workpiece and tool head, and the workpiece is machined consecutively in a first and another second relative position. The operating parameters in the second relative position are controlled such that one or more laser pulse hit locations generated in the second relative position have a defined position with reference to one or more laser pulse hit positions generated from the first relative position, particularly lie in a one- or two-dimensional grid defined by plural laser pulse hit positions on the workpiece surface made from the first relative position.

Abstract: A manifold assembly for an automobile cooling system includes a crossover tube and a crossover tube cover welded in an opening of the crossover tube A flash trap is provided adjacent the region of the weld joint to receive and capture weld flash migrating inwardly in the crossover tube.

Abstract: The invention relates to a soldering material comprising an alloy that in addition to Sn (tin) as the major constituent, comprises 10 wt. % or less Ag (silver), 10 wt. % or less Bi (bismuth), 10 wt. % or less Sb (antimony) and 3 wt. % or less Cu (copper). Furthermore, the invention relates to a soldering material comprising a plurality of soldering components with such alloy compositions and contents in the soldering material that on fusing the soldering components an alloy is formed that comprises Sn, Ag, Bi, Sb and Cu in the abovementioned alloy contents.

Abstract: A downhole tool conveyable within a wellbore extending into a subterranean formation, wherein the downhole tool comprises a first component, a second component, and a solder electrically and mechanically coupling the first and second components, wherein the solder comprises or consists of: from 9.6 to 10.2 weight % of antimony; from 0.01 to 0.25 weight % of manganese; and tin.

Abstract: Processes of joining substrates via transient liquid phase bonding (TLPB). The processes include providing an interlayer of a low melting temperature phase (LTP) that includes Sn and Bi between and in contact with at least two substrates, and heating the substrates and the interlayer therebetween at a processing temperature equal to or above 200° C. such that the interlayer liquefies and the LTP interacts with high melting temperature phases (HTPs) of the substrates to yield isothermal solidification of the interlayer. The processing temperature is maintained for a duration sufficient for the interlayer to be completely consumed and a solid bond is formed between the substrates. Also provided are assemblies formed by the above noted processes.

Abstract: A repair tool and repair method for restoring gas turbine engine blade tips to a predetermined configuration is provided. The repair tool is an electrode that includes a tool body and a number of pins. The repair tool can be used to repair turbine blade tips through an electrical discharge machining process, such as a ram- or sink-type electrical discharge machining process.

Abstract: An alternative-fuel gas orifice, a gas furnace configured to employ the same and a method of designing a gas orifice. In one embodiment, the gas orifice includes: (1) a body having an aperture extending therethrough and including: (1a) a metering neck having a cross-sectional area such that a given flow rate of a gas is established when the gas is delivered to the gas orifice at a given alternative-fuel delivery pressure and (1b) a diffuser having a cross-sectional area larger than the cross-sectional area of the metering neck and a length such that the gas achieves a substantially laminar flow before exiting the diffuser.

Abstract: An accessory device suitable for use with an electronic device is disclosed and may be designed to provide a protective cover and dissipate heat from the device. Regarding the latter, the accessory device may include a thermally conductive layer disposed in the accessory device. The thermally conductive layer may extend from a first end of the accessory device proximate to a heat-generating component in the electronic device, to a second end away from the heat-generating component. The thermally conductive layer is designed to navigate heat away from the heat-generating component to the second end where the heat escapes the accessory device. The second end may include one or more openings to facilitate heat transfer from the accessory device. In other embodiments, the accessory device includes a phase change material that absorbs heat and changes to a liquid, then passes the heat to another location in the accessory device.

Abstract: A method of threadably coupling a first fastener with a second fastener using a rotary drive including a tool. The method includes rotationally anchoring the second fastener relative to the tool by co-axially urging a fastener-engagement portion of the tool against the second fastener and rotating the tool relative to the second fastener using a socket of the rotary drive until the fastener-engagement portion of the tool mates with a receiving portion of the second fastener, receiving the first fastener within the socket of the rotary drive co-axially with the fastener-engagement portion of the tool, and rotating the first fastener with the socket of the rotary drive relative to a housing of the rotary drive to cause the first fastener to threadably engage the second fastener.

Abstract: A manufacturing machine is capable of subtractive manufacturing and additive manufacturing for a workpiece. The manufacturing machine includes: a first headstock and a second headstock disposed in a first processing area and configured to hold a workpiece; a lower tool rest and a tool spindle disposed in the first processing area and configured to hold a tool to be used for subtractive manufacturing for the workpiece; an additive manufacturing head disposed in a second processing area; and a robot arm configured to hold a workpiece and transport the workpiece between the first processing area and the second processing area. The additive manufacturing head is configured to discharge a material toward the workpiece held by the robot arm during additive manufacturing for the workpiece. Accordingly, the manufacturing machine configured simply to be capable of subtractive manufacturing and additive manufacturing is provided.

Abstract: A carpentry featherboard having a curved contact surface generally configured in the shape of a spiral and having a pivot point of the body and a plurality of radii defined between the pivot point and portions of the contact surface, the radii progressively increasing in dimension to define the spiral shape of the featherboard body.

Abstract: A tool magazine includes a magazine arm and a gripper plate. The magazine arm has a tool pot to hold a tool. The magazine arm is pivotable around a pivotal axis such that the tool pot pivots around the pivotal axis. The gripper plate has at least one gripper to hold the tool at a holding position on a circular arc track along which the tool moves when the magazine arm pivots. The at least one gripper is open in a tangent direction of the circular arc track at the holding position.

Abstract: A method to control a power tool, especially a core drill, including a motor as the drive for the power tool, a control unit, a power display, a transmission having at least a first gear and a second gear, a first sensor to detect the rotational speed of at least one component of the transmission and a second sensor to detect the rotational speed of the motor. The method includes the following steps: ascertaining a first rotational speed of the at least one component of the transmission when the transmission has been put into a gear, ascertaining a first rotational speed of the motor when the transmission has been put into a gear, ascertaining the selection of the gear on the basis of a first prescribed ratio of the first rotational speed of the at least one component of the transmission and of the first rotational speed of the motor on the basis of a look-up table, and setting the limit value of the power display on the basis of the look-up table as a function of the gear that has been selected.

Abstract: An air balance mechanism includes a plate part, fixed shafts, and movable cylinders. A flange is provided at one end of each of the fixed shafts. The movable cylinders are movable relative to the fixed shafts. A space is formed below a lower surface of the flange. Further, the air balance mechanism includes fixing bolts and adjusting bolts. The fixing bolts fix the flange and a plate part at positions different from the space. The adjusting bolts are inserted into the plate part through the space for allowing the postures of the fixed shafts to be adjustable.