Abstract: A tool for removing valve springs and seals from an engine's intake and exhaust valves includes a bracket having apertures spaced therealong and for receiving fastening members therethrough. The tool further includes a plurality of support pedestals provided with channels extending therethrough and for receiving the fastening members respectively so that the bracket is maintained at a substantially stable position. The tool also includes a mechanism for simultaneously compressing a valve head keeper and releasing associated locks so that a user can remove the valve springs and valve seals from the valve head. The compressing mechanism cooperates with the pedestals and the bracket and is rotatable about a fulcrum axis traversing the pedestals wherein the fulcrum axis extends along a horizontal plane subjacent the bracket.

Abstract: A compact, easy-to-use, hand tool which is made for the use of installing “Ductmate Clips” on Heating and Air Conditioning sheet metal ductwork utilizing a “Ductmate”, “TDC”, or “TDF” assembly system. The tool is further used in the removal of said “Ductmate Clips”, when ductwork demolition is required.

Abstract: A receptacle which is configured to receive a fastener element having a hexagon, or some other polygonal profile, and which is configured to rotationally or angularly orientate the insert fastener element. One version of the receptacle provides that the receptacle is in the open position as a fastener element is dropped therein. Then, a jaw cylinder closes the receptacle, thereby orientating the fastener element. Another version of the receptacle uses springs instead of a jaw cylinder, and orientates the fastener element upon rotation of a threaded shaft of a pulling head.

Abstract: A method of joining expandable tubulars includes joining the tubulars by forge welding and flushing a reducing flushing gas around the heated tubular ends during at least part of the forge welding operation such that oxides are removed from the forge welded tubular ends and the amount of irregularities between the forge welded tubular ends is limited.

Abstract: A hot rolling mill and method for operating the hot rolling mill where the shape of the strip is controlled by localized cooling devices positioned at intervals along work rolls in at least three lateral zones, a central and two edge zones, and capable of separately cooling each zone to control the shape of the work rolls in that zone and inhibit the formation of shape defects occurring in the strip being rolled. Five zones may be provided across the work surface of the work rolls so that two intermediate zones can control for quarter buckles. The hot rolling mill has particular application in continuously casting thin strip. The method can be made automatic by sensing downstream of the hot mill the shape of the strip in each zone.

Abstract: A method for manufacturing a crank arm and spider assembly includes the following steps: (1) providing a blank; (2) shaping the blank to form a crank billet comprising an elongate body having a first end on which a spider is integrally formed and an opposite end having an expanded outside diameter; (3) forming a channel substantially co-extensive with the elongate body with an opening at the second end of the body; (4) reducing the expanded second end and thereby reducing inside diameter of the channel in proximity of the second for forming an entry of the channel; (5) filling a liquid into the channel through the entry and then sealing the entry; (6) placing the crank billet with the liquid filled in the channel into a mold and performing a mold forging operation to obtain a semi-product; and (7) forming a hole in the body to release the filling liquid out of the channel of the crank.

Abstract: A disk clamp is provided for securing one or more data storage disks to a disk drive without the need for screws. A preloading device is also provided for installing the disk clamp and removing the disk clamp after installation. The preloading device applies a load to the clamp to deflect the clamp, and allows a retaining ring to be positioned between the disk clamp and the hub of the disk drive. Preloading the disk clamp helps to reduce disk drive contamination, potential damage to the motor hub, and improves reworkability of the disk drive. The preloading device can be incorporated within a manually manipulated preloading device, or within an automated assembly process in which the preloading device is incorporated. Methods are also provided for clamp preloading and clamp installation.

Abstract: A fixture with a shaped molding may hold a first micro-actuator part and a second micro-actuator part in place for coupling while maintaining the structure of the first micro-actuator part. The first micro-actuator part and the second micro-actuator part may be a frame or a strip of piezoelectric material. A vacuum nozzle system embedded in the fixture may hold the first micro-actuator part in place. A mobile vacuum nozzle system may hold the second micro-actuator in place and positions the second micro-actuator part relative to the first micro-actuator part. A camera system may monitor the process. A dispense may apply epoxy between the first and second micro-actuator part. An ultraviolet source may provide ultraviolet radiation for curing.

Abstract: A system and method are provided for manufacturing a magnetic head. Initially, a coil structure, a first pole layer, and a gap layer are formed. A second pole layer is then deposited to form a pair of flanking portions flanking a central portion of the second pole layer. Thereafter, the second pole layer is masked with a photoresist layer. During manufacture, the flanking portions of the second pole layer work in conjunction with the photoresist layer to substantially protect the coil structure from damage.

Abstract: Provided is a method of manufacturing a thin film magnetic head capable of achieving compatibility between preventing the occurrence of side erasing and securing overwrite characteristics. When a pole portion layer as a portion where a magnetic flux is emitted is formed, a photoresist pattern is formed so that two frame portions which determine an aperture have a different width from each other, and then the photoresist pattern is heated to deform the frame portions. Thereby, the width of the aperture is gradually reduced toward a seed layer. After that, a precursor pole portion layer is formed in the aperture of the photoresist pattern, and the precursor pole portion layer is polished so as to form an air bearing surface, thereby the pole portion layer is formed so that an exposed surface exposed to the air bearing surface has an asymmetrical inverted trapezoidal shape.

Abstract: In a method for manufacturing a perpendicular magnetic recording head, a groove defined by the inner side surfaces of a first nonmagnetic layer and the top surface of a main magnetic pole layer is formed using the difference in etching rates for dry etching between the main magnetic pole layer and the first nonmagnetic layer. An auxiliary magnetic pole layer is formed on the groove with a nonmagnetic material layer disposed therebetween. A projection integrated with the auxiliary magnetic pole layer is formed in a recess of the nonmagnetic material layer on the groove. This projection extends toward the main magnetic pole layer.

Abstract: A main magnetic pole layer is formed on an insulating layer flattened into a high-flatness surface, and a yoke layer having a large film thickness is formed under the main magnetic pole layer independently of the main magnetic pole. The main magnetic pole layer has a front end surface formed in a shape with a width size gradually increasing in a direction of track width as the front end surface departs farther away from an auxiliary magnetic pole layer. A perpendicular magnetic recording head can be provided which can suppress the occurrence of fringing in a recording pattern, and can form the main magnetic pole layer with high pattern accuracy, and can satisfactorily introduce a recording magnetic field to a fore end of the main magnetic pole layer.

Abstract: A method of manufacturing a flux ring for an electric motor which has a ring with an anchoring mechanism. The ring is placed inside of a die. A first isotropic magnetic material is added into the die such that the anchoring mechanism secures the first isotropic magnetic material onto the ring. A second anisotropic magnetic material is added into the die adjacent the first isotropic magnetic material. The anchoring mechanism secures the second anisotropic magnetic material onto the ring.

Abstract: A strain sensor comprising a metal substrate, a first electrode provided on the metal substrate, a glass layer formed on the first electrode, and a second electrode and a strain detecting resistor provided on the glass layer. In the strain sensor, the insulation resistance between the metal substrate and the second electrode has been raised, and the reliability is high. It can be implemented at low cost.

Abstract: A valve stem installation system includes a robotic arm for moving a valve stem insertion device around the lip of wheel. The system also includes a pair of valve stem aperture sensors positioned on the robotic arm adjacent the valve stem insertion device and moveable around the lip of the wheel. The sensors can be positioned on opposite sides of the valve stem insertion device. When the first sensor locates the valve stem aperture, movement of the robotic arm can be slowed. When the second sensor locates the valve stem aperture, movement of the robotic arm can be stopped. The conveyor unit can include an identification station to sense the configuration of the wheel. A controller can select the appropriate valve stem to insert in the valve stem aperture in response to the sensed configuration of the wheel.

Abstract: The invention provides a mounting method capable of coping with high density mounting, narrower pitch mounting, cavity mounting and the like. In this method, displacement amounts of a chip that is picked up from a wafer by a pick-up nozzle to be held by the pick-up nozzle, with respect to a reference attitude, are obtained, and when the chip is delivered to a mounting nozzle for actually mounting the chip onto a substrate, the displacement amounts are corrected while taking the displacement amounts into consideration, so that the mounting nozzle always holds the chip in a fixed attitude.

Abstract: Method for fabricating a textured dielectric substrate (400) for an RF circuit. The method can include the step (104) of selecting a plurality of dielectric substrate materials, each having a distinct combination or set of electrical properties that is different from the combination of electrical properties of every other one of dielectric substrate materials. Selecting a textured substrate pattern (106) which is comprised of at least two types of distinct areas respectively having the distinct sets of electrical properties, with each distinct area dimensioned much smaller than a wavelength at a frequency of interest. Cutting the dielectric substrate materials (202, 204) into a size and shape consistent with the distinct areas of the selected pattern so as to form a plurality of dielectric pieces (206, 208). Arranging the dielectric pieces on a base plate (302) in accordance with the selected pattern to form the textured dielectric substrate.

Abstract: A method is provided for processing a lead frame. Generally, a first surface of a lead frame base tape is placed on a first surface of the lead frame. A second surface of the lead frame base tape is placed on a first surface of a porous block. A vacuum is placed on a second surface of the porous block. A device for processing lead frames comprises a porous block with a first side and a second side, and a vacuum system connected to the first side of the porous block. The device may also include devices for attaching chips to the lead frame and wire bonding the chips to the lead frame.

Abstract: An electronic device such as a sensor or a NEMS. The electronic device comprises at least one substrate; a plurality of electrodes disposed on the substrate; and at least one nano-wire growing from an edge of a first electrode to an edge of a second electrode. A method for making an electrode structure by providing a substrate; forming a plurality of electrodes on the substrate; growing at least one nano-wire from the edge of a first electrode; and connecting the at least one nano-wire to the edge of a second electrode is also disclosed.

Abstract: The present invention relates generally to a plating buss design and method for minimizing short circuit problems in PCB panel singulation. More particularly, the invention encompasses a serpentine plating buss which increases the PCB singulation process window thereby minimizing short circuit problems due to indexing errors caused by occasional manufacturing and equipment alignment problems. The serpentine plating buss design therefore increases board yield.

Abstract: A method of fabricating identifiable flexible printed circuit board (PCB) disposed to an inkjet cartridge includes, providing a flexible substrate having a first surface. A conductive layer is formed on the first surface. A printing ink layer is coated over the first surface. The printing ink layer is exposed and developed to uncover parts of the conductive layer and form at least one identifiable area on the printing ink layer.

Abstract: After disposing metallic foils on either surface of a prepreg sheet of low compressibility having conducting holes filled with conductive paste, the prepreg sheet is compressed in a state of being kept at a relatively low temperature, and after that, the temperature is raised under pressure to melt and harden the resin in the prepreg sheet, and thereby, the connecting resistance is stabilized, and a high-quality circuit board can be obtained.

Abstract: An improved manufacturing method for a gas sensor is provided which is capable of establishing a required hermetic seal in a body of the gas sensor. The method includes preparing a sensor assembly including a housing, an air cover, an insulation porcelain, and a sensor element, pressing the air cover against the housing to fit an end of the air cover on an end of the housing to form an overlap thereof, and welding the air cover to the housing over the overlap. The welding is accomplished while pressing the air cover against the housing, thereby compressing an elastic member in the air cover to establish a hermetic seal between the sensor element and the housing.

Abstract: Electrically conductive movable elements 15 which are moved from a waiting position to a conduction position by an insertion operation of corresponding male terminals 7 are disposed in all female terminals 9 into which the male terminals are to be respectively inserted in a correct connection condition. Only when the male terminals 7 are correctly inserted into the female terminals 9, the movable elements 15 are moved to the conduction positions to be in contact with conductive portions 17 of a conduction test device 16, respectively, thereby establishing a conductive condition.

Abstract: A method of producing a workpiece forming at least one bearing eye is described, which is divided in the region of the bearing eye along an intended fracture point through a fracture separation, the bearing eye being coated with an anti-friction coating after assembly of the parts. In order to achieve a high load capacity, it is suggested that the bearing eye be processed for a precise fit after assembly of the parts obtained through the fracture separation of the workpiece, before the anti-friction coating is applied to the processed bearing eye surface in a thickness corresponding to the final dimensions.

Abstract: A method for manufacturing a brush seal is provided including the steps of: (a) providing fiber; (b) providing a packing material; (c) providing a pair of backing plates; (d) arranging the fiber in a particular arrangement; (e) applying the packing material to selective areas of the arranged fiber; (f) cutting the fibers in bristle sections, wherein each of the bristle sections includes a plurality of bristles and one of the selective areas having applied packing material; (g) stacking the bristle sections, such that the selective areas of applied packing material are aligned between the backing plates; and (h) bonding the backing plates, the bristle sections, and the packing material together.

Abstract: A method for increasing structural strength of spokes of a bicycle or a motorcycle, which adopts a mechanically processing measure to increase the structural strength of the bending section of the spoke. The spoke is many times compressed to process and harden the bending section of the spoke so as to enhance the metal strength (shearing strength) of the bending section. At the same time, the wire diameter of the spoke (cross-sectional area) is increased due to compression in accordance with the principle that shearing load=shearing strength×cross-sectional area. With least metal material and lower processing cost, the spoke can have highest structural strength.

Abstract: An improved conveyor roller (100) having a belt-engagement length (103) between a first end (101) and second end (102), and a necked-down portion (109) adjacent the second end, and a method of manufacturing such a roller are disclosed. The method comprises forming a roller from a metal tube (12) with a longitudinal axis (106), first and second ends, and an initial outer diameter by: rotating the tube about the longitudinal axis, the tube being substantially free of internal and external supports between the ends thereof, providing rollers (40,41) which are rotatable about corresponding axes generally parallel to the longitudinal axis; and urging the rollers against the tube and moving the rollers between the ends of the tube so as to alter the outer diameter of the tube to form the belt-engagement length and the necked-down portion, the necked-down portion providing a mounting surface for receiving a bearing assembly.

Abstract: A method for manufacturing a combined driveshaft tube and yoke assembly includes the initial step of orienting a first component having a first wall thickness and a second component having a second wall thickness to define an overlap region. The first and second components may have the same or different wall thicknesses, may be formed from the same or different materials, and may have the same or different lengths. Portions of the first and second components are deformed to provide the overlap region with a third wall thickness that is the sum of the first wall thickness and the second wall thickness. Lastly, a pair of yoke arms having respective openings therethrough is formed in the overlap region to provide a combined driveshaft tube and yoke assembly. A pair of combined driveshaft tube and yoke assembly can also be manufactured in accordance with this method.

Abstract: Process for manufacturing cylindrical hollow bodies with a circular cross-section using solid rough material of corrosion-resistant, martensitic chromium steels. A remelting block is produced and a tube blank is made therefrom, the tube blank being formed into a tube at hot forming temperature by extrusion at a deformation ratio of at least 6. Hollow bodies are cut from the resultant tube.

Abstract: A multiple use rotary cutting device having an accessory cutting mechanism for use with prepackaged food products such as pizza. The rotary cutting device provides multiple functions which enhance the convenience of use. The device further minimizes the quantity of devices which must be cleaned after use. The multiple use rotary cutting device has a cutting wheel; a frame member with a lower portion having a accessory cutting surface; a handle assembly comprising a handle cover and a handle for partially enclosing the lower portion of the frame member; and a retracting assembly, which in combination with the handle is capable of completely enclosing the lower portion of the frame member. The accessory cutting mechanism is capable of cutting open a prepackaged food product and the rotary cutting wheel is capable of cutting or slicing the food product itself.

Abstract: In one embodiment of the present invention a laterally folding knife is described incorporating an actuator mechanism permitting the knife blade to be moved from open and closed positions without the need for a user to touch the blade. Further, the folding knife can be quickly opened or closed using a single finger or thumb. The knife blade is automatically locked in place in either open or closed position and therefore does not require a separate blade locking mechanism.

Abstract: A light weight saber saw with reduced numbers of mechanical components and capable of preventing liquid and dust from entering interior of a housing. A plunger reciprocates only in its axial direction in conformity with a longitudinal direction of the housing. A blade holding portion is pivotally movably connected to a front end of the plunger. The blade holding portion includes a plunger chip through which a rear end of a blade is insertable, and a blade holder covering the plunger chip. The blade holder has a track side corresponding to tooth side of the blade, and a track having an inclined track surface is provided at the track side. The housing rotatably supports a roller in rolling contact with the track surface. When the blade is retractingly moved into the housing, the blade holding portion and the blade are pivotally moved totether toward a workpiece by the contact between the roller and the track surface.

Abstract: In a method of tracing a track geometry immediately ahead of a ballast pick-up device of a cleaning machine in a working direction, a first and a second measuring chord are guided on the track by a respective front and rear end point. A versine measured by a first versine sensor of the first measuring chord is stored, in connection with a distance measurement, for registering the rear end point of the first measuring chord as a desired position with respect to a local track point. After the rear end point of the second measuring chord has reached the local track point, the rear end point is displaced until a measurement value corresponding to the stored versine is reached by a second versine sensor, and thus the desired position has been attained.

Abstract: Methods and devices for measuring and calculating wheel alignment angles. Light weight and mechanically robust accelerometers in measurement heads are attached to a vehicle's wheels during an alignment procedure. The output of the accelerometers may be compensated for effects of temperature or thermal hysteresis by memory lookup or a temperature based feedback control loop.

Abstract: A light emitting module and a modular light emitting system with leveling capability. The system relates to light-based (e.g. lower-based) layout tools of the type used in the construction industry. More specifically, the system relates to a modular light emitting system for projection visible patterns, such as dots, lines, cross-lines and other patterns, on one or more distant surfaces for purposes of alignment, construction, verification and the like.

Abstract: A laser leveling device having a suction mounting arrangement includes a housing and a mounting seal extending from the lower portion of the housing. The mounting seal cooperates with an attachment surface to define a suction mounting area therebetween. The suction mounting arrangement cooperates with the mounting seal to maintain the vacuum pressure seal in the suction mounting area. A laser light source mounted within the housing in a planar relationship relative to the attachment surface includes at least one diode projecting an alignment beam through an opening in the housing to denote a reference plane along the attachment surface.

Abstract: Given a situation where a projected laser line appears to have terminated or faded as it intersects with a work-surface (e.g., a wall), a fan-out redirecting means is used to capture and redirect energy radiating above and parallel to, or radiating away from the given work-surface area, where the captured energy is from a line projector mounted to the surface. The radiation capturing and redirecting means aims the captured energy at a greater angle towards the work-surface so that the redirected light is thereafter reflected back to a user to give the perception that a line of enhanced intensity or reborn existence is being created on the work-surface or on a reflective overlayer placed against the work-surface. The radiation capturing and redirecting means may include one or both of optically refractive means and optically reflective means (e.g., lens and mirrors) for performing the capturing and/or redirecting functions.

Abstract: A laser measurement system indicates the difference between an actual position of a vehicle frame reference point on a vehicle frame and a normal position employing a rotating laser scanner; an electro-optical detector and a host computer. A positioning arrangement is also provided for positioning the electro-optical detector at a known distance from the reference point. In operation, the host computer queries the scanner and detector via a communication link, calculates the actual position of the reference point, and displays the difference between the position of the vehicle reference point on the vehicle frame and the normal position.

Abstract: A geomagnetic sensor for auto-calibration of a deviation and a method of using the geomagnetic sensor. The geomagnetic sensor includes a geomagnetic detector including X-axis and Y-axis fluxgates orthogonal to each other and receiving a drive signal to detect an electromotive force corresponding to a geomagnetism, a signal processor converting the electromotive force output from the geomagnetic detector into X-axis and Y-axis output values and outputting the X-axis and Y-axis output values, and a drive signal generator applying the drive signal to the geomagnetic detector. Each of the X-axis and Y-axis fluxgates includes cores, a solenoid type exciting coil, and at least two detection coils winding around the cores in a solenoid form. Accordingly, as an azimuth is measured using output values detected by the separated detection coil, the azimuth can be exactly and easily detected regardless of an external magnetic field.

Abstract: A method for making beaded jewelry is provided. The method utilizes a megaphone shaped device having a small diameter first end and a larger diameter second end. The circumference of the first end is that of one part of the human body, such as a child's wrist. The circumference of the second end is the size of another part of the human body, such as an adult ankle. Markings on the girth of the device sequentially graduate in circumference and define graduated bracelet, anklet and other jewelry sizes. When one is making a bracelet or other article of jewelry of strung beads, the diameter of the beads affects the finished length of the article. Use of the device takes into account the diameters of the beads and thereby ensures that the finished item of beaded jewelry will fit the intended wearer.

Abstract: An instructional template structure for aiding the installation of wall brackets, which is primarily characterized by incorporating a template backboard in a wall bracket packaging box, which can either be placed inside the packaging box or included to the side of the packaging box. Relative dimensions of an assembly hole-boring layout at a scale of 1 to 1 are provided for assembling the rear ends of wall brackets. The template features an improved structural design as the intended purpose and yield that offers an innovative practicality in aiding the installation of wall brackets in a swifter and more precise manner.

Abstract: A miter measuring tape, for allowing a workman to readily and quickly measure a section of window or door frame casing stock from the inside point of a miter cut end of said stock section, having a tape measure with a hooking member of adjustable and fixable length pivotally connected to one end of said tape measure at the proximal end of said hooking member, with said hooking member having a hook at the distal end of said hooking member, said hook being used to secure the miter measuring tape to the outside point of said miter cut end of said stock section.

Abstract: A device to measure the height of a person consists of an elongated base that extends from above the head of the person being measured to the flat surface on which the person stands and a sliding member. The base has two longitudinal channels, one containing a T-track and the other a measuring scale. There is a blank surface on which to record the height and other additional data. Decorative indicia may also be placed on the blank area. The vertically movable sliding member has a forward extending bar that rests against the top of the head of the person being measured. A follower extends from the side of the sliding member across the channel containing the scale. The top edge of the follower is at the same level as the bottom surface of the bar. The height can be read along the top edge of the follower. The sliding member has a threaded bolt extending through it with a tab on the back end which is movable within the T-track and prevents the sliding member from being pulled out of the T-track.

Abstract: Glassy articles are prepared by subjecting to hydrolysis and policondensation a solution or suspension of a suitable precursor, mainly comprising a silicon alkoxide, and by drying the obtained gel in a pressure chamber, the gel solvent having been substituted by a non-protic solvent, mainly acetone, under nitrogen flowing, at temperature and pressure conditions lower than the gel solvent critical values. The dried gel is then densified by a thermal treatment.

Abstract: A wafer dryer and method featuring a nebulizer which emits a pressurized drying liquid stream that converges with an opposed pressurized non-reactive carrier gas stream to produce a drying liquid fog. The pressurized non-reactive gas spray device is disposed partially within a tub and partially within a wafer bath vessel housing a wafer to be dried. The tub has a vent port for allowing the drying liquid fog to pass into the wafer bath vessel to adhere to exposed wafer surfaces and displace remaining liquid on wafer surfaces, thus drying the wafer. The tub may further include a drain for draining drying liquid not converted into the fog or which has condensed. The vent also may include means for retaining larger drying liquid fog particles which allows smaller drying liquid fog particles to pass into the wafer bath vessel.

Abstract: As a metal assembly, which defines partially open voids in which liquid accumulates is conveyed through a heat-treating station, the hot air is blown across the open end of the void to produce a zone of low pressure at the surface of the liquid. The reduction in pressure and relatively high temperature promote rapid vaporization of the liquid while discouraging boiling of the liquid.

Abstract: A device for drying sludge originating in a waste water treatment plant is enclosed in a greenhouse having a floor for receiving a bed of sludge to be dried. The greenhouse employs solar energy. A spreader located in the greenhouse ensures the the sludge is spread over the floor and turned as it progresses along the drying device. Fans are positioned over the spreader to provide for the renewal of air present in said greenhouse. A controller controls start up and shut down of a drying cycle as well as automatic control of all motorized components in response to measurement of the temperature of the surface of the bed of sludge. The controller also takes into account the difference in temperature between the surface of the bed of sludge to be dried and the atmosphere present in the drying plant, equipment in the greenhouse only being started up when this temperature difference reaches a predetermined set point.

Abstract: An outsole (1, 3), in particular, for athletic shoes (2) can be realized with a significant elastic deformability in the tangential direction so as to also achieve a superior shock-absorption when the foot contacts the ground obliquely and with a slight propulsive force. According to the invention, the sole (1) essentially is only rigid to a tangential deformation beyond at least one critical point of deformation in the region that is deformed to this critical point. This results in a correspondingly increased stability for the runner in the respective point of contact or load application. The runner is also able to push off from the point of load application without any loss in distance. A floating effect on the sole is prevented.

Abstract: A cushioning member for an article of footwear. The cushioning member is a flexible bladder having a fluidly interconnected heel chamber and forefoot chamber. The bladder is disposed above the sole and beneath the wearer's foot to provided added cushioning to the wearer. The bladder contains air at slightly above ambient pressure and can be formed by thermoforming or by welding two sheets of resilient, flexible material together. A connecting passage fluidly connects the heel chamber and the forefoot chamber. The connecting passage is narrow to control the flow of air between the two chambers.