An apparatus includes a head transducer configured to interact with a magnetic recording medium and a heater configured to thermally actuate the head transducer. A thermal sensor at or near the head transducer is configured to produce a sensor signal. Circuitry is coupled to the heater and configured to cause an oscillation in heater power. The heater power oscillation causes an oscillation in the sensor signal. A detector is coupled to the thermal sensor and configured to detect head-medium contact using the oscillating sensor signal and heater power.

An inner peripheral surface of a tube-shaped inner casing has a regular hexagonal shape when viewed from the axial direction, a plurality of pins are arranged in the inner casing so as to take a posture parallel to the axial direction of the inner casing, and in this arrangement, a plurality of rows of the pins arranged in a predetermined direction are arranged in a direction perpendicular to the row direction of the pins, the adjacent pins of the adjacent rows are offset from each other in the row direction of the pins, and each pin contacts the pins adjacent thereto.

Disclosed are: a casting aluminum alloy that is excellent in elongation as alternative properties of a high cycle fatigue strength and a thermal fatigue strength and is suitably usable for a casting for which both of the excellent high cycle fatigue strength and the excellent thermal fatigue strength are required, for example, an internal combustion engine cylinder head; a casting made of the aluminum alloy; a manufacturing method of the casting; and further, an internal combustion engine cylinder head composed of the aluminum alloy casting and manufactured by the manufacturing method of the casting. The casting aluminum alloy contains, in terms of mass ratios, 4.0 to 7.0% of Si, 0.5 to 2.0% of Cu, 0.25 to 0.5% of Mg, no more than 0.5% of Fe, no more than 0.5% of Mn, and at least one component selected from the group consisting of Na, Ca and Sr, each mass ratio of which is 0.002 to 0.02%.

An anatomical model assembly of the human head for use in teaching medical personnel. The anatomical model has an inner base that is shaped as part of the human skull. A first layer of material covers the base. The first layer of material provides a visual indication of at least some muscle groups contained within a human head. A second layer of material is provided that covers the first layer. The second layer of material has an exterior that is shaped with at least some human facial features. The second layer of material and the first layer of material are separate, unattached layers. The material selected for the first layer mimics the suppleness of muscle. The material selected for the top second layer mimics the feel and elasticity of skin. The result is an anatomical model that can be used to accurately teach, plan and practice medical procedures.

The adjustable headset is an all in one device that includes an adjustable support band, a display system, a first and second ear cover, a computer system, a communications system, and a power source. The adjustable support band connects to each ear cover, with the ear covers being adjacent to a user's ears. The display system uses binary screens to create the experience of looking at large screens by taking up most of a user's field of view. The display system is attached to the ear covers by adjustable screen bars, which allow a user to change the general orientation of the display system. The computer system is capable of storing and running software programs and interfacing with connected devices by means of a set of connection ports or the communications system. The virtual goggles can adjust to meet individual comfort needs and interface with a variety of technologies.

A gripper head for the insertion of weft threads on a gripper weaving machine as well as a gripper weaving machine with such a gripper head. The gripper head thread clamp for the weft thread is controlled in a contact-free manner and with high transfer reliability of the weft thread even in the machine center.

A mobile device case includes a reel assembly, including a reel, a supporting plate, and a hub between the reel and the supporting plate. The hub includes a first cavity between the hub and the supporting plate for housing a spring, and a second cavity between the hub and the reel for housing a flat flexible cable (FFC). The spring is wound in a first direction, while the FFC is wound in a second direction. The FFC includes a first end for electrically coupling to a female jack connector of a device. A female connector is electrically coupled to a second end of the FFC for engaging a male jack connector of user-provided headphones. When the reel rotates in the first direction, the spring tightens and the FFC loosens. When the reel rotates in the second direction, the spring loosens and the FFC tightens.

A tree processing head for processing a tree element. The tree processing head includes: a body; a scissor assembly mounted to the body and a chainsaw assembly also mounted to the body. The scissor and chainsaw assemblies are selectively usable individually or cooperatively to process the tree element.

An articulated cutting head and conveyor mount for sod harvesting machines. The invention provides a linkage design that can provide many benefits including: allowing the operator to see the cutting operation, enabling the high lifting of the cutting head for service and maneuvering, managing the vertical bending load of the ground reference roller, providing high transverse stiffness, maintaining the position of the conveyor relative to the cutting head. The linkage design can include fewer parts than previous designs while still being robust and durable. As such, cutting heads employing the linkage design of the present invention can produce higher quality slabs with less service and maintenance than when using current designs.

A scan head assembled to a scan arm for an ion implanter and a scan arm using the same are provided, wherein the scan head is capable of micro tilting a work piece and comprises a case, a shaft assembly, an electrostatic chuck, a first driving mechanism and a micro-tilt mechanism. The shaft assembly passes through a first side of the case and has a twist axis. The electrostatic chuck is fastened on a first end of the shaft assembly outside the case for holding the work piece. The first driving mechanism is disposed within the case and capable of driving the shaft assembly and the ESC to rotate about the twist axis. The micro-tilt mechanism is disposed within the case and capable of driving the shaft assembly and the ESC to tilt relative to the case.

A damping tool holder, such as a boring head, a chuck, or a milling cutting arbor, integrates a damping device (2), in the form of an elongated body. The damping device (2) is housed in a mounting body (3), connected by one end to the tool-holder body (1) and having at its other end an end fitting (4) for mounting a tool, whereby the mounting body (3) is equipped with at least one lubricant feed pipe (32), emptying at its front end into the end fitting (4) for mounting a tool and connected at its other end to a circular groove (102) for distributing lubricant that is provided on the front surface of the tool holder (1).

Embodiments of the present invention generally provide chamber components with enhanced thermal properties and methods of enhancing thermal properties of chamber components including bonding materials. One embodiment of the present invention provides a method for fabricating a composite structure. The method includes applying a bonding material to a first component, and converting the bonding material applied to the first component to an enhanced bonding layer by heating the bonding material to outgas volatile species from the bonding material. The outgassed volatile species accumulates to at least 0.05% in mass of the bonding material. The method further includes contacting a second component and the enhanced bonding layer to join the first and second components.

The present invention discloses a kind of universal mounting hole means for different tool heads of electric tools, which are disposed on a mounting portion of the tool head, comprising a central hole and a plurality of long and narrow limiting holes which orient radially surrounding the central hole and disposed in distance with each other. Compared with the prior art, the present invention is applicable to various kinds of structures of the mounting seat on electrical tool and is more universal. It takes much convenience to people when changing different tool heads of electric tools, and it is benefit for storing.

A welding head is provided. The welding head includes a bracket and a plurality of blocks coupled to the bracket. Each of the plurality of blocks has a contact tip. The contact tips are adapted to receive an electrode. Further, at least one of the plurality of blocks is capable of variable positioning relative to the bracket.

A coupler head for a coupling arrangement is shown, which coupler head includes a coupler head housing (6) extending in a longitudinal direction from a first end (6a), attachable to a drawbar, to a second end (6b), which is arranged to carry a coupling interface between coupled rail vehicles, which coupler head housing houses mechanical coupling components (8,9) effective for automatic coupling to the corresponding components of a connecting coupling arrangement. The coupler head is characterized in that the coupler head housing has at least one notch (11, 11') for a predetermined and primarily axial compression thereof with absorption of energy from a deforming compressive force that is applied to the coupler head in the longitudinal direction thereof. The coupler head has preferably at least one notch (11, 11') for a predetermined folding of the coupler head housing.

A headrest assembly (1) for an ejection seat, comprising: a support mounting (2); and a pair of inflatable side beams (3), each attached at one end to the support mounting and spaced apart from one another, the side beams (3) being configured to be inflated from a stowed configuration to a deployed configuration in which the side beams extend from the support panel, the side beams (3) configured to deploy through: a capturing phase, during which the side beams are partially inflated from the stowed configuration such that they extend outwardly and upwardly from the support mounting and away from one another to surround the head of an occupant of the ejection seat toward a central location with respect to the support mounting.

A system for diverting fluids from a wellhead in a subsea environment has a capping stack with a connector suitable for connection or interconnection to the wellhead, a flow base fixedly positioned in the subsea environment, and a conduit connected to the outlet of a diverter line of the capping stack and connected to the inlet of an interior passageway of the flow base. The conduit is suitable for passing fluids from the capping stack toward the flow base. The flow base is a modified horizontal Christmas tree. The interior passageway within the horizontal Christmas tree has a plug therein located a level below the level of the inlet to the flow base. The flow base can be attached to a wellhead or to an anchor pile in the subsea environment.

The present invention features a coke drum de-heading system that includes a de-header valve. The de-header valve includes: (1) a main body; (2) a live loaded seat assembly coupled to the main body and comprising a dynamic, live loaded seat, a live seat adjustment mechanism coupled to the main body and designed to control and adjust the force and resulting seat load of the dynamic, live loaded seat, and a force transfer module in juxtaposition to the dynamic, live loaded seat for transferring the force from the live loaded seat adjustment mechanism to the dynamic, live loaded seat; (3) a static seat positioned opposite from and counteracting or counterbalancing the dynamic, live loaded seat; and (4) a blind or sliding blind capable moving in a linear, bi-directional manner within the de-header valve and between the dynamic, live loaded seat and the static seat.

A cosmetic applicator comprising a handle having a proximal end and a distal end, wherein the handle comprises a drive; an applicator head operatively associated with the drive to move at least part of the applicator head relative to the handle; and a control surface disposed at the proximal end of the handle and operatively associated with the drive. The control surface may be rotatable about a control surface axis through a plurality of positions and the control surface axis may be aligned with the longitudinal axis of the handle. The control surface may be moveable through a plurality of positions. The applicator may comprise an additional control surface, such as a second control surface or temporary control surface, which may be operated independently or in combination with the first control surface.

A self-actuating tension head for a strapping machine includes a body defining a strap path, a drive wheel, a tension wheel a fixed distance from the drive wheel and a pinch wheel. The strap path extends between the tension and pinch wheels. A first link operably connects the drive and tension wheels and defines a first pivot arm that is pivotable about the drive wheel axis of rotation. A second link operably connects the tension and pinch wheels and defines a second pivot arm that is pivotable about the pinch wheel axis and movable along the second pivot arm to move the tension wheel into and out of engagement with the pinch wheel. The first and second pivot arms define an energizing angle therebetween that decreases as the tension wheel is moved into engagement with the pinch wheel and increases as the tension wheel is moved out of engagement with the pinch wheel.

The present invention provides a method for improving operation density of rail vehicles and for preventing head-on collision and rear-ending collision. Said method divides a rail line into equidistant electronic zones, the length of a zone being greater than the shortest safe distance between two running vehicles. Said method installs a locomotive passing detection alarm device in each zone, when a locomotive travels at high speed on the rail, the locomotive passing detection alarm device corresponding to the zone occupied by the locomotive itself will simultaneously access adjacent front and back zones, and determine whether the two adjacent zones are simultaneously occupied by locomotives. If the two adjacent. zones are simultaneously occupied by locomotives, the locomotive passing alarm device will send an alarm signal to the locomotives to warn or otherwise take measures. The aforesaid method can avoid locomotive head-on collision and rear-end collision and increase transportation density according to the vehicle speed and distance at the same time, thus improving the transportation efficiency.

A method of and apparatus for positioning and supporting any of several different elongated workpieces of circular, substantially square, or substantially non-square rectangular cross-sectional configuration so that a central workpiece axis is located along the same axis for any one of said workpieces includes a tailstock fixture for supporting one end of the workpiece which includes a frustoconical cavity that extends coaxial with the axis for receiving the one end of the workpiece, and a headstock fixture for supporting a second end of the workpiece opposite the first end which includes a generally cylindrical cavity extending coaxial with the axis and four equiangularly spaced workpiece engaging blades within the cylindrical cavity for engaging and supporting the second workpiece end.

A transverse adjustment mechanism for a bilateral half-spring type load-carrying head is installed in the casing of the load-carrying head of the lifting unit of a pit type unwheeling machine, fixedly connected with the casing, directly connected to an adjustment unit at the end of the load-carrying head, and installed on a lead screw of the adjustment unit. The transverse adjustment mechanism includes an adjusting nut, an adjusting nut guide, a guiding tube, and a guiding sleeve, a nut mounting plate, a flange plate, a compression spring and a sliding shaft. The invention is currently applied to the transverse adjustment of the no-loading heads and transverse fine adjustment of the load-carrying heads of a China Railway High-speed (CRH) train. The structure is reliable and practical, safe, convenient and energy-saving to use and satisfies the demand for the synchronous lifting operation of the entire CRH train of the compatible pit type unwheeling machine.

A rotary spray head assembly includes a motor having an output shaft and a housing through which the output shaft at least partially extends. The housing includes an inlet communicable with a source of fluid. The rotary spray head assembly also includes an annular skirt extending from the housing, a passageway through the skirt having a first end in fluid communication with the inlet and a second end, and a hub coupled for co-rotation with the output shaft. The hub includes an annular groove into which the annular skirt at least partially extends, a circumferential interior surface at least partially defining the groove, and an aperture through the circumferential interior surface. Fluid introduced into the annular groove through the second end of the passageway is discharged outwardly through the aperture.

The invention relates to a marking and/or scanning head comprising a plurality of receiving spaces in which individual marking and/or sensing devices can be arranged for marking and/or scanning an object, wherein the receiving spaces are arranged in at least two sub-arrays, wherein at least one sub-array is movable and/or rotatable with regard to at least one other sub-array. The invention further relates to a marking and/or scanning apparatus and a method for operating a marking and/or scanning head or apparatus.

Provided are apparatus and systems having a poppet valve assembly and swing adsorption separation techniques related thereto. A poppet valve includes a valve body, a plurality of static valves fixedly secured to the valve body and a single dynamic poppet valve having a plurality of openings. The plurality of static valves align and mate with the plurality of openings. The single dynamic poppet valve reciprocates to selectively open and close the plurality of static valves.

The present invention relates to a device for wetting or lubricating a rail head (7). The device has at least one outlet (30) for a wetting agent and/or lubricant. To ensure that the noise generated by a track-bound vehicle is reduced safely and regardless of the weather, a rail head-side end portion (33) of the at least one outlet (30) is movably mounted between a position at a remote distance from the rail head (7) and a position in closer proximity to the rail head.

The present invention is directed to a method for production preformed fabrication casing or associated parts intended to generate fragments initiated by the explosive of contained warhead charges. Molded parts having fragmentation bodies (4, 21, 34) embedded therein are produced by a two-stage powder compaction method followed by sintering together the compacted powder metal. The method described in the present invention defines how in an initial stage the fragmentation bodies (4, 21, 34) are fixed in position using a fixture (2) after which the bodies are covered with powder metal that is then compacted until the powder forms a single molded part (2) after which the fixture is replaced with a secondary quantity of powder that is also compacted to form a self-supporting unit (12) together with the first quantity of powder.

The present invention provides a method and apparatus of reducing current requirements by increasing resistance of the blade structure by reducing the cross sectional area of at least one section of the blade so that the electrical current requirements for heating of the blade to cutting temperature are reduced wherein the power supply and substantially entire unit may be mounted within a hand held unit. Methods of shaping blades to perform various heat distributions for specialty blades for custom cutting are disclosed. Further, an improved blade mounting structure is provided which includes structure for maintaining the legs of the blade parallel to the direction of cut and provides for easy insertion of new blades by maintaining a slotted blade cradle stable and in alignment with the blades and a clamp member away from the blade when the clamp mounting structure is loosened.

Apparatus and method are provided for making the longitudinal temperature distribution of the bulbous end of a longitudinally oriented workpiece, such as a rail's head, generally uniform when the head has a non-uniform longitudinal temperature distribution. A combination of crown and skirt electric inductors is used to achieve the generally uniform temperature distribution by modulating the magnetic field intensity produced by current flow through one or more of the combination of crown and skirt inductors as required for the non-uniformly heated regions of the rail's head.

Embodiments of club head covers having a pull strap and methods to manufacture club head covers are generally described herein. Other embodiments of club head covers having a pull strap may be described and claimed.

A head cover for a golf club includes a first surface having a removable cleaning pad thereon, and a second surface on which at least one golf accessory constructed of a ferrous metal is removably attached thereto. The second surface is part of a tri-layer construction with magnets forming the second middle layer so as to so retain the golf accessory thereon. The cleaning pad is removed by the golfer from the first surface and includes a scrubbing area to remove grit and/or debris from one of a golf ball and a golf club face.

A golf club head cover. Implementations may include a body portion defining an internal cavity for receiving a golf club head, a first flap disposed on the body portion and including a first magnetic fastener, and a second flap disposed on the body portion and including a second magnetic fastener. The first magnetic fastener and second magnetic fastener may substantially align with each other and may be aligned substantially parallel with the internal cavity of the body portion. Particular implementations may include a notch adjacent to the internal cavity and/or reentrant openings on both a side of the first flap and on a side of the second flap.

A surface cleaning head is provided comprising a dome-shaped, downwardly open housing, in which at least one spray arm is mounted for rotation about an axis of rotation, wherein the spray arm bears at a distance from the axis of rotation a nozzle which can be acted upon with cleaning fluid subject to pressure and revolves around the axis of rotation together with the spray arm, and comprising a protective disk which covers the at least one spray arm towards the open underside of the housing and defines a ring-shaped fluid passage for a stream of fluid to pass through, said fluid passage being penetrated by retaining bars, wherein the at least one spray arm is rotatable relative to the protective disk. The retaining bars are arranged so as to be distributed unevenly in circumferential direction.

Headbands configured to provide pressure against a medical sensor secured to a patient's forehead are provided. The headbands may include one or more low friction materials to enable an elastic band of a tensioning mechanism to evenly stretch. Additionally or alternatively, the headbands may include two or more bands adapted to secure the headband to various portions of a patient's head. Still further, the headbands may be configured to independently vary the pressure created between two or more sensors and the patient's head.

A knitting head of a knitting machine for manufacturing flexible hoses (1) with a knitted reinforcement layer, which comprises a guide body (14) with a central tubular conduit (15) for the passage of the bearing layer (2) and having a outlet end portion (16) with a first outer peripheral surface (17) having a first predetermined radius (r1), a plurality of knitting needles (18) arranged along the periphery of said end portion (16) of said conduit (15) and having first longitudinal end sections (18') arranged along the circumference of said outer peripheral surface (17) and second longitudinal end sections (18″) arranged over a second cylindrical surface (19) having a second radius (r2) greater than said first radius (r1), at least one disk-shaped cam element (22), which is adapted to rotate at a first rotation speed and has a third predetermined radius (r3). The third radius (r3) is greater than said second radius (r2), connection means (23) being provided for connecting said disk-shaped element (22) to said second end sections (18″) of said needles (18), said connection means (23) having at least one longitudinal portion (24) with a radial dimension decreasing from said third radius (r3) to said second radius (r2).

A wrench including a handle having a first yoke at a first end and a first plurality of tool heads coupled to the first yoke at a first pivot axis, at least a first tool head of the first plurality of tool heads having a drive cavity. Each tool head of the first plurality of tool heads is pivotable about the first pivot axis independently of the other tool heads of the first plurality of tool heads.

A temperature controlled showerhead assembly for chemical vapor deposition (CVD) chambers enhances heat dissipation to provide accurate temperature control of the showerhead face plate and maintain temperatures substantially lower than surrounding components. Heat dissipates by conduction through a showerhead stem and removed by the heat exchanger mounted outside of the vacuum environment. Heat is supplied by a heating element inserted into the steam of the showerhead. Temperature is controlled using feedback supplied by a temperature sensor installed in the stem and in thermal contact with the face plate.

An electrical ground (36) of an RF impedance matching network (33) is connected to a connection area (50) on the grounded chamber cover (18) of a plasma chamber. The connection area is offset away from the center of the chamber cover toward a workpiece passageway (20). Alternatively, an RF power supply (30) has an electrically grounded output (32) that is connected to a connection area (52) on the chamber cover having such offset. Alternatively, an RF transmission line (37) has an electrically grounded conductor (39) that is connected between a grounded output of an RF power supply and a connection area (52) on the chamber cover having such offset.

This application includes a number of embodiments of a spring powered toothbrush for cleaning teeth. A wind-up spring is located in the base of the toothbrush which spring provides power for a gear train including a drive shaft assembly that is designed to bring about rapid movement of the brush portion of the toothbrush to aid in cleaning the teeth. The drive mechanism is controlled by a spring biased push button in the toothbrush housing. In one version the brush portion of the toothbrush includes a rotatable brush section that is gear driven by the drive shaft. In another version the upper portion of the toothbrush is vibrated by an offset weight connected to the drive shaft and in a third version the drive shaft includes an offset weight that acts to oscillate a movable brush section by intermittent engagement between the; weight and brush section.

The present invention provides a thermal print head and a thermal printer that can deliver improved printing quality. The thermal print head includes a main substrate with a main surface, heating elements arranged along a main scanning direction, and a protection layer that covers the heating elements. A belt-shaped heating glaze layer is between the main surface and the heating elements, extends along the main scanning direction, and bulges towards the direction where the main surface faces. The surface shape of the protection layer has an equivalent radius of curvature Re between 6200 μm and 15000 μm. The equivalent radius of curvature Re is calculated by Hq and Wq. Hq is ¼ of the maximum height Hm of the bulging portion of the protection layer including the heating glaze layer. Wq is the width of the bulging portion along a sub-scanning direction, measured at a height equal to Hm minus Hq.

A thermal print head includes a semiconductor substrate, a resistor layer and a wiring layer. The resistor layer is formed on the semiconductor substrate and has a plurality of heat generating portions arranged in the main scanning direction. The wiring layer is formed on the semiconductor substrate to be included in a conduction path for energizing the plurality of heat generating portions. The conduction path includes a path or paths provided by the semiconductor substrate itself.

A thermal print head includes a semiconductor substrate, a resistor layer with heat generating portions arranged in the main scanning direction, a wiring layer included in a conduction path for energizing the heat generating portions, and a protective layer covering the resistor layer and the wiring layer. The semiconductor substrate includes a projection protruding from the obverse surface of the substrate and elongated in the main scanning direction. The projection has first and second inclined side surfaces spaced apart from each other in the sub-scanning direction. The heat generating portions are arranged to overlap with the first inclined side surface of the projection as viewed in plan view.

A piezoelectric element is manufactured in a method including forming an adhesion layer of zirconium above a zirconium oxide insulating film, forming a first electrode above the adhesion layer, forming a piezoelectric layer of a complex oxide containing bismuth above the first electrode, and forming a second electrode above the piezoelectric layer.

The present invention relates to a steamer head for a garment steamer comprising a main body (2) with a front end (8), a steam outlet (11) and an air inlet (25) formed in the front end (8). A suction force is applied to draw air through the air inlet (25) so that a fabric of a garment disposed proximate the front end (8) is drawn against the front end (8) by the suction force. Further, steam is applied to the fabric of a garment through the steam outlet (11). The front end (8) of the main body (2) comprises first and second surfaces (10, 2). The steam outlet (11) is formed in the first surface (10) and the air inlet (25) is formed in the second surface (12), so that the fabric is drawn against the second surface (12) and steam is applied to the fabric at the first surface (10). The first and second surfaces (10, 12) together forma convex surface. The present invention also relates to a garment steamer comprising a 10 steamer head and a method of removing creases from a garment using a garment steamer.

An automated variable speed control system for a cutter head of a dredging cutter has a cutter head and a pump. The pump pumps cuttings from the cutter head through a cuttings discharge line. A sensor monitors amperage draw of the pump. A controller controls speed of movement of the cutter head based upon data received from the sensor. The controller increases a speed of movement of the cutter head through the materials when the amperage draw of the pump falls below the determined amperage range and the controller decreases the speed of movement of the cutter head through the materials when the amperage draw of the pump exceeds the determined amperage range.

Disclosed is an engine that comprises an engine block, and the engine block comprises a cylinder. The engine further comprises a cylinder head mounted to the engine block, and the cylinder head comprises an intake valve seat and a shroud. Further yet, the engine comprises a combustion chamber formed at least partially by the cylinder and the cylinder head. The intake valve is configured to travel between a fully closed position seated against the intake valve seat and an opened position displaced from the intake valve seat, thus allowing intake flow through the intake valve seat into the combustion chamber. The shroud only partially surrounds a periphery of the valve and extends along at least a portion of the travel of the intake valve so as to restrict intake flow along only a portion of the intake valve.

A fastening structure of a fuel delivery pipe and a cylinder head of an internal combustion engine includes three or more bosses provided on each of the cylinder head and the fuel delivery pipe, and fastening portions formed by bolting the bosses on the cylinder head to the bosses on the fuel delivery pipe. The fastening portions at both end portions of the fuel delivery pipe are less rigid than one or more fastening portions in a middle between the fastening portions positioned at both end portions of the fuel delivery pipe.

The present invention relates to an encoder readhead. The readhead includes a housing having an opening for capturing an encoder scale including an elongate rod having a substantially circular cross-section, the opening defining an axial direction along which a captured encoder scale can slide back and forth. A scale reader, which may include an array of Hall sensors, is provided for reading a portion of an encoder scale located in the opening. The housing includes an access portion that allows the encoder scale to be inserted into, and/or removed from, the opening by a relative movement between the housing and the encoder scale in a direction other than the axial direction.

Systems and methods for providing aircraft heading information are provided. In one embodiment, an attitude heading reference device comprises: at least one interface for receiving heading information from one or more IRUs; at least one set of gyroscopes and accelerometers; a memory device for storing data representing heading information received via the at least one interface; and a heading calculator coupled to the at least one interface, the at least one set of gyroscopes and accelerometers, and the memory device. The heading calculator generating a heading output signal based on heading information when reliable heading information is received over the at least one interface; the heading calculator generating the heading output signal based on data from the memory device regarding previously reliable heading information and an output of the at least one set of gyroscopes and accelerometers when reliable heading information is not received over the at least one interface.