Abstract: A vacuum assembly having a housing and a motor and motor shaft secured within the housing; a fan coupled to the motor shaft and an air intake port and an air exhaust port located within the housing; a circuit board mounted in a cooling air path in the housing, wherein the cooling air path is located between the air intake port and the air exhaust port such that the fan causes cool air to flow across the circuit board; a pulley assembly coupled to the motor shaft and including a disposable belt, the pulley assembly located in the housing in such position that the circuit board blocks access to the disposable belt; a first connector portion secured to the circuit board; a second connector portion coupled to a plurality of wires coupled to at least the motor; the first and second connector portions configured to mate in a single direction.

Abstract: A swivel caster has a caster body, a pivot bearing and a foot that can be extended by means of an electric motor. The foot has a telescoping foot part. The electric motor is disposed below the pivot bearing, at least below a first, upper bearing.

Abstract: A caster for moving a thing is disclosed. The caster comprises a first rotary shaft which is installed at a plate on which a thing to be moved is positioned; a rotation body of which one portion is rotatably engaged to the first rotary shaft; a frame of which an upper side is rotatably connected to the other portion of the rotation body; and a wheel which is rotatably installed at a lower side of the frame.

Abstract: A locking device for keeping a window or sliding door from opening beyond a predetermined limit includes telescoping inner and outer members. A fastening mechanism selectively locks the inner member and the outer member. In one embodiment, the outer member has a first lateral side with a series of holes on one side spaced apart at a first distance and the second lateral side with a series of holes spaced apart at a second distance. The holes allow fine length adjustment of the locking device. The fastening mechanism is press-fit inside the inner member and includes a push pin to lock the inner member and outer member. The push pin is integrated on a c-shaped clip to spring-bias the push pin in place within the inner member. In another embodiment, the fastening mechanism extends from the inner member and rotation of the inner member locks enables the fastening mechanism to lock against the outer member.

Abstract: A fitting for displaceably supporting sliding doors made of glass, including an adhesive adapter glued onto a door leaf. The adhesive adapter is fastened to a roller carriage by a fastening element. The roller carriage has an adapter support, at which the fastening element is disposed, and in that the roller carriage has an adjuster for adjusting the height of the sliding door.

Abstract: A leash handle includes a hollow tubular body having a first end and a second end. A handle end having a knob is partially inserted into the second end of the hollow tubular body so that the knob remains outside the hollow tubular body. A first chamber within the hollow tubular body is accessible when the handle end is removed from the hollow tubular body. A second chamber of the hollow tubular body is accessible through an opening in the hollow tubular body adjacent to the tip.

Abstract: A hinge has a pintle, a spacer assembly, a stationary bracket and a rotating bracket. The pintle is mounted through the spacer assembly and is connected to the stationary and rotating brackets. The spacer assembly has multiple spacers stacked with each other. Each spacer has a ring segment and a bearing segment. The ring segment is mounted around the pintle. The bearing segment has an absorbing space to absorb the stress acting on the ring segment. Therefore, the spacer sustains less stress to prevent breakage easily and a lifespan of the spacer is extended. Therefore, the hinge has a longer lifespan.

Abstract: A hinge for mounting a door-panel or window sash to a fixed jamb element has two leaves pivoted together about an axis. One of the leaves is adapted for attachment directly to an edge of one of the elements. A housing is recessed in the other of the elements and has a pair of generally parallel and vertical side walls with inner faces defining a horizontally open cavity. A bar is shiftable in the cavity horizontally perpendicular to the side walls and vertically. At least one fastener releasably securing the other of the leaves to the bar. A pair of spindles extending perpendicular to the side walls in the cavity are threaded into the bar and have opposite ends bearing on the inner faces of the side walls so that rotation of the spindles shifts the bar perpendicular to the side walls.

Abstract: A hinge has a pintle, a spacer assembly, a stationary bracket and a rotating bracket. The pintle is mounted through the spacer assembly and is connected to the stationary and rotating brackets. The spacer assembly has multiple spacers stacked with each other. Each spacer has a ring segment and a bearing segment. The ring segment is mounted around the pintle. The bearing segment has an absorbing space to absorb the stress acting on the ring segment. Therefore, the spacer sustains less stress to prevent breakage easily and a lifespan of the spacer is extended. Therefore, the hinge has a longer lifespan.

Abstract: The embodiment includes a hinge, a pivot shaft, a cam, and a cam follower. The pivot shaft includes an engaging portion bound by two curved surfaces and two non-rotatable surfaces. The cam is non-rotatably sleeved on the engaging portion of the pivot shaft and defines a noncircular hole and two cutouts. The noncircular hole is bound by two first contact surfaces and two second contact surfaces. The second contact surfaces are tangent to the curved surfaces of the engaging portion of the pivot shaft. The cam follower is rotatably sleeved on the engaging portion of the pivot shaft and resists the cam. The cam follower forms two peaks engaging with the cutouts in the cam.

Abstract: Door construction includes a door panel and at the top and at the bottom each time a self-closing pivot hinge. Each of the pivot hinges includes a spring which extends along the rotation axle and which provides a self-closing function to the pivot hinge. Each of the pivot hinges includes a first cam element and a second cam element which are pushed onto each other by the spring and push the door panel towards the closed position under the influence of the spring pressure. The first cam element includes at least one protrusion which upon rotation runs along a running surface with inclined parts of the second cam element. The second cam element is movably mounted in longitudinal direction of the pivot axle by means of a pen which is accommodated in a slotted hole of the second cam element. The slotted hole extends at least partly between the inclined parts of the running surface.

Abstract: A hinge includes a fixing member, a shaft fixed to the fixing member, a rotating member, an interfering member, and a fastener. The shaft includes a shaft post, and the fastener is fixed to a distal end of the shaft post. The interfering member defines a fixing hole departing from a center of the interfering member, and includes two guiding surfaces. The rotating member defines an oblong adjusting hole, through which the shaft post rotatably passes. A first resisting stub and a second resisting stub extend from the rotating member, to resist against the corresponding guiding surfaces. The shaft post is fixedly received in the fixing hole. When the rotating member is rotated relative to the shaft post, the first and second resisting stubs always resist against and move along the corresponding guiding surfaces, to urge the shaft post to relatively move in the adjusting hole.

Abstract: A hand grip for the handle or shaft of a device is disclosed. The hand grip provides a waterproof, comfortable and optionally heated hand grip for a user. The hand grips find use, for example, on or around handles of sporting equipment and accessories, garden tools, wheelchairs, umbrellas, prams and pushchairs; and on or around the shaft of an umbrella.

Abstract: An extendable device engages and operates a handle mounted on an electrical switching apparatus. The extendable device includes a first linear portion and a second linear portion, each of the first and second linear portions having a first end and a second end, a handle adaptor extending away from the second end of one of the first and second linear portions and a retainer mechanism structured to engage the first linear portion and the second linear portion such that the extendable device can be adjusted to a particular length and maintained at the particular length. The handle adaptor is structured to engage the handle such that the handle can be moved from a first position to a different second position.

Abstract: A method for hanging an object and apparatus for accomplishing the same. The invention describes an apparatus comprising a track, an upper flange attached to a track, and a carrier disposed in said track. The carrier is laterally moveable along the length of the track. In one embodiment the apparatus comprises a top unit and a base unit. The top unit comprises pins, a track, at least one carrier, and a lower flange. The base unit is affixed to a ceiling, and the top unit is affixed to the base unit via the pins. In one embodiment the anchors are not visible from below. Further, in one embodiment, the lower flange acts as a moisture barrier to protect the anchors.

Abstract: The apparatus comprises a gripper for securely holding an object and a holder for attaching to a surface. The holder is secured to the gripper and is operable to be attached to the surface at a location away from area where the gripper is secured to the holder. The gripper is capable of movement so as to engage and disengage with the object. The holder is capable of movement so as to engage and disengage from the surface. The holder and the gripper engage and disengage with the surface and the object respectively by moving in directionally different planes to ensure a secure grip during engagement.

Abstract: Standard pin badges used for police, fire, EMS and security uniforms attach to thin uniform shirts with no other means of support. This gives the badge an unstable platform allowing the badge to flop around on the uniform. That movement creates an unprofessional appearance and possible safety risks of catching on equipment or other people when in close contact. The BadgeKeeper, resolves those issues by attaching behind a pin badge and under a uniform shirt to provide support, stabilization and added safety.

Abstract: A clip 10 is provided for the retention of cables or wiring 44 in electrical installation trunking 46. The clip 10 has a first member 12 and a second member 14, which are coupled together in a sliding relationship. In use, the clip 10 slides apart, extending across the open face 50 of the trunking 46 until the lateral ends of the clip abut against an internal side wall 52 of the trunking 46. Cooperating locking strips (26, 40, see FIGS. 3 and 4) act to lock the relative positions of the first 12 and second 14 members and to prevent the clip 10 from falling out of the trunking 46.

Abstract: A resilient rotation buckle includes a decoration plate and the belt coupling structure having an end coupled to a belt. The decoration plate and the belt coupling structure form a rotation shaft and a rotation assembly that cooperate each other. The rotation assembly includes a receptacle compartment having a wall forming a through hole for receiving the rotation shaft therethrough, springs, and retention blocks. An accommodation channel is defined in the receptacle compartment in a direction normal to the through hole. When the rotation shaft is inserted, the retention blocks are in contact engagement with an outer circumference of the rotation shaft. The springs have first ends in biasing engagement with the retention blocks and second ends supported by walls of the accommodation channel. The rotation shaft and the rotation assembly allow for relative rotation therebetween for switching between a locked position and a released position.

Abstract: A retaining device for retaining an object or objects to a surface or surfaces. The device is comprised of an elongate, flexible strap having a plurality of bores and a retaining member embedded within a platform body. The retaining member has first and second portions. The first portion has a first end which is passed through one or more of the bores of the strap to operatively connect the strap to the retaining member. The strap is placed around the object to be retained. The second portion retains the first portion in a closed position so that the object is retained securely but non-permanently. An adhesive between the platform body and the surface permanently fixes the retaining device to the surface.

Abstract: A magnetic clip is provided having two magnetic components to create a low-cost, thin, soft magnetic vise- like mechanism. The magnetic components are disposed in individual stickers or a unitary sticker. The clip includes an adhesive layer to which a real banknote may be removably attached. The user can simply peel back the banknote to open the magnetic vise-like mechanism to insert or remove one or more banknotes. The user then folds the substrate back onto itself to close and secure the remaining banknote(s).

Abstract: In slide fasteners (10, 40, 50), separable pins (31, 51) have projecting portions (31b, 51b) projecting toward box pins (32, 32?, 52), and the difference between the interval A between the inner surfaces of right and left flange portions (24) at the rear ends of sliders (21a, 21b) and the maximum value B of dimension of the separable pins (31, 51) in the tape width direction (interval A?maximum value B) is set to satisfy the relation “(dimension C of a portion of the box pin (32, 32?, 52) in the tape width direction corresponding to a portion of the separable pin (31, 51) having the maximum value B)<(interval A?maximum value B)<(element width D of the fastener element (15))”, the maximum value B is set to be smaller than the element width D, a dimension E of the area in a tape length direction where the dimension of the separable pins (31, 51) in the tape width direction is larger than the difference between the interval A and the element width D (interval A?element width D) is set to satisfy a relation

Abstract: According to embodiments of the present invention, there is provided a closed-end treatment structure for a slide fastener of a vehicle seat, the structure including: a pair of cloth tapes to be attached to a seat skin of the vehicle seat; a pair of teeth lines respectively attached to the pair of cloth tapes; a slider configured to move from a top stop side to a bottom stop side while detachably meshing the teeth lines; a pull-tab connected to the slider through a connection portion; and a storing portion configured to store the slider, the pull-tab and end portions of the cloth tapes, in a state where the slider is moved to the bottom stop side, thereby storing the closed-end of the slide fastener.

Abstract: Improvements to panel fastening clips, especially to those used in curtain and/or lateral airbags, of the kinds of clips that are formed by a surface and/or several flexing arms that are designed to be located in the outer part of the panel into whose opening they are inserted, including several feet that are more or less elastic and that tend to converge at their ends in the general shape of an inverted “V” in the direction in which the clip is inserted, as well as several wings whose ends work against the lower surface of said panel and which ensure that said clip is fastened to said panel, characterized by the fact that the ends of said wings have an enlarged working surface against the lower surface of said panel.

Abstract: A clamping device has a toggle lever mechanism (2) with a linearly movable actuator (1) and a pivot shaft (23) with a tensioning arm (21). A mechanism to unlock an over-center position is coupled with the toggle lever mechanism. The mechanism includes a control element (3) that is arranged on the actuator (1) and a rocker (4). The rocker (4) can be brought into adjusting contact with the control element (3). The control element (3) is in the form of a control extension in a direction facing away from the pivot shaft. The actuator (1) is arranged between the pivot shaft (23) and the rocker (4).

Abstract: A seat belt system includes a tongue member, a latch member for detachably engaging the tongue member, a release member for releasing engagement between the tongue member and the latch member and a slide switch configured to communicate whether the tongue member is engaged with the latch member. The slide switch includes a sliding member configured to slide between first and second positions and a printed circuit board. The sliding member includes a first sliding contact member and a second sliding contact member. The printed circuit board includes a first printed circuit board contact member that contacts both the first and second sliding contact members when the sliding member is in the first position. When the sliding member moves from the first position to second position the first sliding contact member is configured to break contact with the first printed circuit board contact member before the second sliding contact member.

Abstract: A switch-equipped buckle device capable of accurately detecting an attachment-detachment state of a tongue plate by mounting fixed contacts immovably therein. The switch-equipped buckle device has, inside a buckle body, a slide switch that detects a state of attachment of the tongue plate according to the sliding position of an ejector. A slider of the slide switch is integrated with the ejector, and three fixed contacts of the slide switch are integrated with a lower case by insert molding.

Abstract: A machine and a method for treating fabrics, comprise in combination a step of inducing substantially vertical vibrations in a quantity of fabric in the form of a substantially compact mass and a simultaneous step of drying the rest of the fabric in opened-out form.

Abstract: A semiconductor device manufacturing equipment includes a plurality of heat treatment plates for performing a post-exposure bake (PEB), a first storage section for storing a first relation, said first relation being an association relation between post-development resist pattern dimensions and a preset temperature during the PEB, a second storage section for storing a second relation, the second relation being an association relation between post-etching pattern dimensions and the preset temperature during the PEB, a primary correction section for obtaining post-development resist pattern dimension data for each of a plurality of first substrates processed separately by the plurality of heat treatment plates, and for primarily correcting the preset temperature for each of the plurality of heat treatment plates based on the first relation; and a secondary correction section for obtaining post-etching pattern dimension data for each of a plurality of second substrates.

Abstract: A method of manufacturing an electrolytic capacitor according to the present invention includes the steps of: forming a capacitor element by winding an anode foil having a roughened surface on which a dielectric film is formed, a cathode foil, and a separator containing a synthetic fiber and a water-soluble binder; immersing the capacitor element in a chemical conversion solution containing water as a main solvent for re-chemical conversion; subjecting the capacitor element subjected to re-chemical conversion to first heat treatment at a temperature of not less than 60° C. and less than 100° C.; and subjecting the capacitor element subjected to the first heat treatment to second heat treatment at a temperature of not less than 150° C. and less than a melting point of the synthetic fiber.

Abstract: A method includes the following steps: forming a porous anode body using powder of valve metal or an alloy thereof; forming a dielectric layer on the surface of the anode body; soaking the anode body having the dielectric layer in a liquid containing a conductive-polymer monomer, thereby making the monomer adhere to the dielectric layer of the anode body; forming a first conductive polymer layer by soaking the anode body having the monomer adhered thereto in an oxidizing agent solution, thereby polymerizing the monomer by liquid-phase chemical polymerization; forming a second conductive polymer layer by bringing the conductive-polymer monomer into contact with the surface of the anode body having the first conductive polymer layer in a gas phase, thereby polymerizing the monomer by gas-phase chemical polymerization; and forming a third conductive polymer layer by soaking the anode body having the second conductive polymer layer in a liquid containing a monomer of a conductive polymer layer, thereby polymerizi

Abstract: A crimping assembly is provided for securing a cover part to a structural member. The crimping assembly includes a housing, a drive shaft disposed within the housing and rotatable in a first direction, and a first roller fixedly secured to the drive shaft and rotatable therewith. The crimping assembly also includes a slide shaft disposed within the housing and rotatable in a second direction. A second roller is fixedly secured to the slide shaft and rotatable therewith. A drive mechanism is operably coupled to the drive and slide shafts to roll the first and second rollers over the cover part to secure the cover part to the structural member. A coupling mechanism is operably connected between the drive shaft and the slide shaft to allow movement of the slide shaft towards and away from the drive shaft during operation of the crimping assembly to accommodate variations in flange thickness.

Abstract: When a chamber of an oscillator and one or more amplifiers is to be replaced at the timing when a predetermined period elapses, one of the chambers of the oscillator and the amplifiers having a low allowable deterioration limit is detached and this chamber is attached in place of one of the chambers of the oscillator and the amplifiers other than the one having the low allowable deterioration limit. Thus, the chamber which has been used in one of the oscillator and amplifiers having a low allowable deterioration limit and has not reached the limit of deterioration is reused in one of the oscillator and the amplifiers other than the one having the low allowable deterioration limit. This enables efficient use of oscillator and amplifier chambers in a multistage amplification laser apparatus, minimizing the labor and parts consumed for replacement thereof.

Abstract: The invention relates to a method and to a device for fully automatically selecting and packing photovoltaic solar modules (6) produced in mass production, having the following characteristics: a) a production line (1), b) a quality checking device (2) having devices for mechanical final testing and electrical final testing, c) an assembly device (3) for module carriers, d) a device for distributing and stacking (4, 15) the solar modules (6) in the horizontal and vertical direction according to particular selection criteria at acceptance locations corresponding to said selection criteria, e) devices for placing strips (19) as spacers between stacked modules, wherein different types of strips can be taken from a magazine, f) devices for collating packages of a plurality of solar modules (6) at each acceptance location, wherein said devices each comprise a film wrapper (7), a protective cap applicator (8), and a strapping device (9).

Abstract: Disclosed is a composite roofing shingle. The preferred roofing shingle includes a mixture of a polymer and a filler. The preferred blend includes between about 35-65% polyethylene and 50-70% crushed limestone filler.

Abstract: The present invention is directed toward spiral wound modules along with methods for making and using the same. Several embodiments are described including methods for making spiral wound filtration modules using membrane sheet provided from a roll, wherein the membrane sheet is unrolled and assembled in a direction parallel to the permeate collection tube of the module.

Abstract: According to an aspect of the invention, a golf club includes: a golf club head having a hosel; a shaft; a shaft case fixed to one end of the shaft, and inserted into the hosel, the shaft case being formed in a substantially cylindrical shape; and a ring-shaped screw member screwed into one end of the hosel to fix the shaft case in the hosel, the ring-shaped screw member being detachable from the hosel;

Abstract: A method of running a first tubular within a second tubular includes running the first tubular into the second tubular past at least one lateral extending from the second tubular, running a diverting tool at the first tubular with the running of the first tubular, withdrawing the first tubular from the second tubular until an end of the first tubular is beyond a junction between the at least one lateral and the second tubular and, running the first tubular into the at least one lateral.

Abstract: An assembly for symbolically indicating a person's desire or wish will be granted, and methods of using the assembly. A symbolic device in the shape of a wishbone, limited to having only first and second bodies. Each of the first and second bodies have first and second ends. The first ends of the first and second bodies are releasably coupled at a union of the first ends of the first and second bodies. The symbolic device is open between the second ends of the first and second bodies when the first ends of the first and second bodies are releasably coupled at the union of the first ends of the first and second bodies. The method for symbolically indicating a person's desire or wish will be granted comprises providing the assembly and separating the releasably coupled first ends of the first and second bodies of the symbolic device.

Abstract: A method for making catalytic converters with automated crack detection includes forming a rigid housing, providing a substrate shaped for reception in the housing, and forming a mat shaped to cover the exterior surface of the substrate and having a thickness which creates a tight friction fit between the substrate and the housing when the same are assembled. The mat is wrapped around the substrate, and the wrapped substrate is then stuffed into the housing using a reciprocating ram or the like that extends at a relatively constant speed. The stuffing force and the ram position are measured and recorded regularly to define an array of data. The data is analyzed for any abrupt changes in the stuffing force as a function of the ram position indicating a crack in the assembled substrate.

Abstract: The invention concerns an arrangement for anchoring a beam or a bar against an element for example a camera tripod and solves the problem of securing said beam or bar using only one hand. The mechanism comprises a screw-fit connection in the form of a locking or holder sleeve which locates a shaft or round tube and which has a locking ring at one end, the other end being externally threaded, cone-shaped and slit. This thread cooperates with an internal thread in a spherical, slit ring sleeve mounted inside a spherical cavity in one end of the object to which the shaft or tube is being secured. The other end of the object includes a means for securing it to a tripod or similar stand. The shaft or tube can be moved or adjusted in any direction and at any angle inside the sleeve, so long as the sleeve and its cone-shaped part are not screwed into the ring sleeve.

Abstract: A phase-transitional material, a method of manufacturing thereof, and a method of manufacturing a module with the phase-transitional material are disclosed.

Abstract: A method of assembling a conduit assembly comprises positioning a ferrule over an end portion of an elongate conduit body. The method further comprises positioning a body insert into the end portion of the elongate conduit body. The end portion of the elongate conduit body is positioned between the ferrule and the body insert. The method further comprises expanding a portion of the body insert positioned inside the elongate conduit. The method further comprises positioning an elongate cable in the elongate conduit body. The elongate cable is longer than the elongate conduit body. The method further comprises filling at least a portion of the elongate conduit body with a potting material.

Abstract: A device to rivet two pieces together each having aligned holes comprising a rivet holder body having a cylindrical hole there through, an upper punch and a lower punch coaxially disposed along an axis of a cylindrical hole presented in the rivet holder body; structure for guiding a rivet to the rivet holder body in a selected orientation as well as structure for catching the falling rivet in the cylindrical hole when the upper and lower punches are in a first separated position and to withdraw from the cylindrical hole as the upper punch moves relative to the lower punch to a second riveting position.

Abstract: Couplers for attaching an accessory to an excavator arm of an excavator. Couplers having a first side for attaching the coupler to the excavator arm and a second side onto which the accessory will be coupled. The coupler includes a latch for selectively securing and releasing an attachment pin of the accessory in a jaw, groove, hook or slot in the second side of the coupler. The coupler is fully controllable from within the cab of the excavator and it allows improved security in the securement of the accessory to the coupler, i.e. preventing accidental decouplings, but while still allowing intentional decoupling operations to be carried out without undue burden.

Abstract: A wind turbine is proposed which has a plurality of construction sections each having at least one connection region for connecting at least two construction sections to one another, a plurality of fasteners to fasten at least two connection regions of two construction sections to one another, and an identifier for each fastener to distinguish it from other fasteners. A testing device to test the fasteners of a construction section of a wind turbine having a tool section for tightening and/or retightening the fasteners to obtain a desired tightness and/or to test the fasteners with regard to tightness, and a detection unit for detecting an identifier of each fastener.

Abstract: The invention relates to a riveting tack (50) to be introduced into coaxial openings of at least two elements to be assembled, and comprising a hollow cylindrical body (51), a rod (53) passing through the hollow body and partially provided with an external thread (52a), a nut (54) mounted on the threaded end (53a), two half-clips (56) fixed to the rod (53) and comprising hooking lips (57) on the ends thereof, and a spacer (58) arranged between the two half-clips (56), the rod/half-clip set being axially mobile along the spacer (58) between a first position wherein the hooking lips (57) are radially close, and a second position wherein the two half-clips (56) are retracted inside the hollow body (51) and radially distanced from each other. The invention is characterized in that the set formed by the half-clips (56) and the spacer (58) is, in the cross-section thereof, in the form of a near-perfect circle having a diameter identical to the inner diameter of the openings.

Abstract: The shank (12) of a disposable rotary cutting tool (10) comprises a pipe section (16) cut from a drawn metal pipe. The tool head (14) is formed from a cut-out (18a, 18b) of a drawn metal sheet or a section of a metal tube by non-cutting machining. The pipe section (16) and the tool head (14) are advantageously attached by force fitting.

Abstract: A workpiece machining method includes attaching a workpiece to a workpiece support with the aid of joining means. The workpiece and the workpiece support are joined to one another by an annular joining means. The composite produced is machined. The machined workpiece is separated from the workpiece support.

Abstract: A wafer holding apparatus for holding a wafer in a semiconductor fabrication apparatus includes a stage having a wafer receiving area with a large number of apertures. A gas, supply source supplies gas to the apertures to levitate the wafer by gas pressure. The levitated wafer is held in contact with a retainer disposed above a peripheral part of the wafer receiving area by the gas pressure, which the retainer resists. The wafer is thereby held securely even when the stage is moved, and the surface configuration of the wafer is not affected by the presence of foreign matter between the wafer and stage.