Patent ID: 12221225

Illustrative embodiments are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein and wherein:

The drawing figures do not limit the invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.

DETAILED DESCRIPTION

The following detailed description references the accompanying drawings that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.

In this description, references to “one embodiment,” “an embodiment,” or “embodiments” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate references to “one embodiment,” “an embodiment,” or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, act, etc. described in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the technology can include a variety of combinations and/or integrations of the embodiments described herein.

Embodiments are generally directed to a sensor lift mechanism for use in an aircraft to deploy and retract a sensor from an aircraft compartment while the aircraft is being operated over a large range of airspeeds. While typical lift mechanisms often comprise frames mounted substantially parallel to the floor of an aircraft with a sensor disposed below the frame, the sensor lift mechanism of embodiments described herein may be mounted substantially sideways within a tail cone of the aircraft such that the sensor lift mechanism is substantially parallel to the side walls of the tail cone with the frame disposed behind the sensor. By utilizing the sideways orientation, the sensor lift mechanism may be installed into aircraft having preexisting systems (e.g., refrigeration systems) in the tail cone. The sensor lift mechanism may utilize a set of rollers that allows for the sensor lift mechanism to react to the unconventional loads resulting from the sideways mounting orientation. The rollers may translate on roller tracks that are configured to prevent any induced damaged from propagating to other components of the sensor lift mechanism. The use of rollers instead of commonly-used slide bushings may substantially eliminate any debris from being trapped within the mechanism that would reduce the ability for the sensor lift mechanism to operate. The arrangement of the rollers may also produce less friction than other sensor lift mechanisms. The sensor lift mechanism may comprise a substantially rigid platform in which a sensor may be installed. The platform may have a roller carriage assembly on which the set of rollers are disposed. A first subset of the rollers may ride in a linear track, and a second subset of the rollers may ride on a track plate. The rollers may be arranged to function as discrete load paths to react to substantially any loads imposed on the sensor lift mechanism during operation.

FIG.1Aillustrates an overview of the sensor lift mechanism100in relation to other aircraft components for some embodiments. Sensor lift mechanism100may be disposed within a tail cone of an aircraft (seeFIG.1B) and may be positioned substantially above a track door102. During operation of sensor lift mechanism100, track door102may open inwards within the plane and forwards towards the nose of the plane, thereby leaving an opening (not shown) for sensor lift mechanism100to deploy a sensor therethrough. Track door102may be disposed within a portion of fairing access panel104, and fairing access panel104may be disposed on an outer surface of the tail cone and provide maintenance access to the inside of the tail cone. A first isolator beam106aand a second isolator beam106bmay be disposed on opposite sides of sensor lift mechanism100and are configured to reduce vibrations and dampen forces applied to sensor lift mechanism100when in a deployed position. Isolator beams106a,106bmay comprise an isolating material to aid in reducing vibrations as will be discussed further below. First isolator beam106amay be disposed on a forward side of sensor lift mechanism100, and second isolator beam106bmay be disposed on an aft side of sensor lift mechanism100as shown. In some embodiments, isolator beams106a,106bextend transversely across the inside of the tail cone of the aircraft. As illustrated below with respect toFIG.4A, platform structure206may rest on isolator beams106a,106bwhen deployed. Isolator beams106a,106bare discussed in further detail below with respect toFIGS.4A and4B.

FIG.1Billustrates a left-hand isometric view, andFIG.1Cillustrates a right-hand isometric view of the positioning of sensor lift mechanism100within a tail cone108for some embodiments. As shown inFIG.1B, sensor lift mechanism100may be mounted onto a side wall110of tail cone108via mounting assembly112. Mounting assembly112may comprise a series of links, brackets, hinges, bolts, screws, clamps, and the like for securing sensor lift mechanism100to side wall110. Mounting sensor lift mechanism100to side wall110may allow for the installation of sensor lift mechanism100in tail cone108without having to adjust or reposition any equipment or machinery already present. For example, aircraft often have refrigeration systems114(seeFIG.1C) installed that take up a substantially large amount of space in tail cone108. As such, it may not be feasible to install a mechanism with a frame disposed across the fuselage. Thus, installing sensor lift mechanism100in the illustrated position allows for the deployment of a sensor out of tail cone108without having to adjust any preexisting systems. However, embodiments are not limited to mounting sensor lift mechanism100at the illustrated position, and sensor lift mechanism100may be installed in nearly any location within tail cone108. For example, sensor lift mechanism100may be installed to a structural member disposed near the center of tail cone108.

FIG.2illustrates an isometric view of sensor lift mechanism100for some embodiments. Sensor lift mechanism100may comprise sensor202, elevator frame204, platform structure206, roller carriage assembly208, sensor platform210, adapter plate212, a drive unit213comprising gearbox214and motor215, a first limit switch216a, a second limit switch216b, a third limit switch216c, and a fourth limit switch216d(seeFIG.3A). Broadly, sensor lift mechanism100operates by drive unit213powering roller carriage assembly208to raise and lower sensor202out of the opening formed by opening track door102. In some embodiments, drive unit213powers a ball screw as will be discussed further below with respect toFIG.9. The motion of sensor lift mechanism100may be guided by a set of track rollers disposed on roller carriage assembly208. The track rollers may have a discrete load path to allow sensor lift mechanism100to withstand substantial loads imposed during operation.

In some embodiments, sensor202is a camera, a radar, a lidar sensor, or any other sensor. In some embodiments, sensor202has a diameter of about 16 inches to about 26 inches. In some embodiments, sensor202has a diameter of about 20 inches. In some embodiments, sensor lift mechanism100is configured to hold a sensor202having a weight of about 245 pounds. Alternatively, other payloads besides sensors may be deployed and retracted from an aircraft compartment using sensor lift mechanism100without departing from the scope hereof.

Platform structure206may connect roller carriage assembly208to sensor platform210via a series of bolts, screws, welds, mounting plates, or mounting brackets. In some embodiments, platform structure206comprises a substantially thin piece of metal, such as aluminum, stainless steel, or titanium. In some embodiments, platform structure206comprises first trigger218a, second trigger218b(seeFIG.3B), third trigger218c, and fourth trigger218d(seeFIG.3B) configured to trigger limit switches216a,216b,216c,216d. In some embodiments, adapter plate212is connected to sensor platform210, attaches to sensor202, and is configured to receive various sized sensors202in sensor lift mechanism100.

Limit switches216a,216b,216c,216dmay control the end travel points of roller carriage assembly208. When triggers218a,218bapproach or contact limit switches216a,216b, respectively, which are disposed near the top of elevator frame204, sensor lift mechanism100may be considered to be in a retracted position, with sensor202disposed within tail cone108. When triggers218c,218dapproach or contact limit switches216c,216d, respectively, which are disposed near the bottom of elevator frame204, sensor lift mechanism100may be considered to be in a deployed position, with sensor202disposed substantially outside of tail cone108. When any of limit switches216a,216b,216c,216dare triggered, a signal may be sent to drive unit213to power off. Fourth limit switch216dmay be disposed opposite third limit switch216cand below second limit switch216b, as shown inFIGS.3A and3B. In some embodiments, various other proximity sensors may be used as limit switches216a,216b,216c,216d, such as infrared, conductive, or inductive proximity sensors or optocouplers.

FIG.3Aillustrates sensor lift mechanism100in the retracted (e.g., stowed) position for some embodiments. In some embodiments, sensor lift mechanism100also comprises a support plate301connecting roller carriage assembly208to sensor platform210. In some embodiments, support plate301is fastened to a bottom face of roller carriage assembly208near a top end of support plate301and fastened to a back face of sensor platform210near a bottom end of support plate301. As illustrated, in the retracted position, the various components of sensor lift mechanism100are held substantially near the top (i.e., near drive unit213) of sensor lift mechanism100and within tail cone108.

As shown inFIG.3B, sensor lift mechanism100is in the deployed position and roller carriage assembly208has translated downwards from the position illustrated inFIG.3Avia drive unit213powering ball screw302. At the illustrated position, triggers218c,218dmay have triggered third limit switch216cand/or fourth limit switch216d, thus pausing motor215. In some embodiments, sensor lift mechanism100extends about 15 inches to about 26 inches vertically between the retracted position and the deployed position. In some embodiments, sensor lift mechanism100extends about 18.5 inches vertically between the retracted position and the deployed position. Looking now atFIG.3C, the deployed position of sensor lift mechanism100is illustrated with respect to tail cone108of the aircraft. As shown, sensor202may deploy out of the opening formed by retracting track door102and into the airstream to collect sensor data. In some embodiments, sensor lift mechanism100is triggered to deploy sensor202upon a detected opening of track door102. For example, when track door102is fully opened, a signal may be sent to drive unit213to begin deploying sensor202. Once third limit switch216cand/or fourth limit switch216dare triggered, drive unit213may be deactivated. Thereafter, a second signal may be sent to sensor lift mechanism100to retract sensor202back within tail cone108. In some embodiments, when first limit switch216aand second limit switch216bare triggered during retraction, a signal is transmitted from sensor lift mechanism100to track door102to initiate the closing of track door102in tail cone108. In some embodiments, sensor lift mechanism100deploys in about 16 seconds to about 22 seconds. In some embodiments, sensor lift mechanism100deploys in about 18.5 seconds. In some embodiments, sensor lift mechanism100retracts in about 20 to about 30 seconds. In some embodiments, sensor lift mechanism100retracts in about 22 to about 23 seconds at a flight speed of about 300 knots.

FIG.4Aillustrates a right hand, isometric view of sensor lift mechanism100in the deployed position for some embodiments, as shown, sensor platform210may rest on and abut isolator beams106a,106bwhen sensor202is deployed. As described above, isolator beams106a,106bmay be disposed substantially laterally within tail cone108. In some embodiments, isolator beams106a,106bcomprise a length of about 22 inches to about 26 inches. In some embodiments, isolator beams106a,106bcomprise a length of about 24 inches. In some embodiments, isolator beams106a,106bcomprise an isolating material418(seeFIG.4B) to aid in vibration damping, as will be discussed in further detail below. In some embodiments, first isolator beam106aand second isolator beam106bare substantially similar.

First isolator beam106amay comprise a first isolator402aand a second isolator402b, and second isolator beam106bmay comprise a third isolator402cand a fourth isolator402d. In some embodiments, first isolator402ais aligned with third isolator402c, and second isolator402bis aligned with fourth isolator402d, as depicted inFIG.4A. In some embodiments, isolators402a,402b,402c,402dare substantially circular, cylindrical, square, rectangular, hexagonal, or any other geometric shape. Sensor Platform210may comprise a substantially square or rectangular shaped body with four outriggers404a,404b,404c,404dextending outwards. In some embodiments, first outrigger404aand second outrigger404bextend towards the forward end of the aircraft, and third outrigger404cand fourth outrigger404dextend towards the aft end of the aircraft. First outrigger404amay correspond to first isolator402a(seeFIG.4B), second outrigger404bmay correspond to second isolator402b, third outrigger404cmay correspond to third isolator402c, and fourth outrigger404dmay correspond to fourth isolator402d. Alternatively, sensor lift mechanism100may be rotated 180 degrees to face opposite the direction shown inFIG.4Asuch that first outrigger404acorresponds with fourth isolator402d, second outrigger404bcorresponds with third isolator402c, third outrigger404ccorresponds with second isolator402b, and fourth outrigger404dcorresponds with first isolator402a. Broadly, sensor lift mechanism100may be mounted in any orientation (i.e., oriented towards the front, back, left or right) within tail cone108. In some embodiments, when sensor lift mechanism100is deployed, outriggers404a,404b,404c,404dare configured to mate with isolators402a,402b,402c,402das will be discussed in further detail below. By resting sensor lift mechanism100onto isolator beams106a,106b, vibrations that would propagate to sensor202may be reduced.

In some embodiments, isolator beams106a,106bare configured to attach to intercostals406within tail cone108via bolts, screws, nuts, brackets, clamps, welds or other similar fastening means. In some embodiments, intercostals406are structural beams of tail cone108. Intercostals406may support loads applied to isolator beams106a,106b. Intercostal406may be disposed substantially perpendicular to isolator beams106a,106b(e.g., extending in the forwards-to-aft direction). In some embodiments, isolator beams106a,106bare removable from the aircraft and may be detached from intercostals406.

FIG.4Billustrates a cross section of the interface of first isolator402aand first outrigger404acut along the A-A line illustrated inFIG.4Afor some embodiments. In some embodiments, isolators402a,402b,402c,402dare substantially similar. In some embodiments, outriggers404a,404b,404c,404dare substantially similar. As described above, when sensor lift mechanism100deploys, sensor platform210may lower and abut against isolator beams106a,106b. Isolator beams106a,106bmay be configured to substantially resist the compressive force from sensor lift mechanism100and the lateral/longitudinal load during operation. Isolators402a,402b,402c,402dand outriggers404a,404b,404c,404dmay serve to reduce lateral and longitudinal forces applied. As illustrated, isolators402a,402b,402c,402dare separate components from isolator beams106a,106bthat are then fastened to isolator beams106a,106b. In some embodiments, isolators402a,402b,402c,402dmay be formed as part of isolator beams106a,106bsuch as via a casting process, for example. Alternatively, isolator beams106a,106b, could be formed with holes or slots and isolators402a,402b,402c,402dinserted therein.

First isolator402amay comprise a receptacle408for receiving a dagger pin410. The dagger pin410is an extension of the first outrigger404aoriented vertically for insertion into receptacle408. Receptacle408may be a substantially cylindrical opening oriented vertically as shown. In some embodiments, receptacle408is substantially circular, rectangular, or any other geometric shape configured to receive a similarly shaped dagger pin410therein. In some embodiments, first isolator402acomprises upper isolator housing412for guiding dagger pin410into isolator402a. In some embodiments, upper isolator housing412is disposed on an inner surface of receptacle408. Upper isolator housing412may comprise a substantially conical taper such that, in the event dagger pin410is not directly aligned with the center of isolator402a, dagger pin410may contact upper isolator housing412, and the taper may help self-align dagger pin410into isolator402a. In some embodiments, dagger pin410comprises a rounded distal end413which may be configured to assist with aligning dagger pin410within upper isolator housing412(e.g., the rounded shape of distal end413may have a curvature that matches the conical taper of upper isolator housing412). In some embodiments, upper isolator housing412comprises stainless steel, aluminum, titanium, or any combination thereof. First isolator402amay also comprise lower housing414on either side of receptacle408. In some embodiments, lower housing414comprises at least one opening for receiving a fastener therein, such as bolts416for example, thus securing first isolator402ato first isolator beam106a. As illustrated best inFIG.4A, lower housing414may encompass a perimeter of first isolator402a. In some embodiments, lower housing414comprises stainless steel, aluminum, titanium, or a combination thereof.

In some embodiments, isolator beams106a,106b(including isolators402a,402b,402c,402d) comprise isolation material418that provides vibration dampening for first isolator beam106a. By utilizing isolation material418with isolator beams106a,106b, isolator beams106a,106bmay function substantially similar to a mechanical spring.

In some embodiments, isolation material418comprises a rubber, an elastomer, or a thermoset material. In some embodiments, isolation material418comprises cold-cast silicone rubber. The use of isolation material418and the mating of isolators402a,402b,402c,402d, with outriggers404a,404b,404c,404dmay allow for isolator beams106a,106bto substantially dampen vibrations from the airstream that propagate to sensor202.

Turning now toFIG.5, a planar view of sensor lift mechanism100is illustrated for some embodiments. As shown, elevator frame204may comprise a lower beam502, an upper beam504, a first vertical beam506a, and a second vertical beam506b. In some embodiments, elevator frame204is substantially rectangular with lower beam502disposed opposite upper beam504and vertical beams506a,506bdisposed substantially perpendicular to lower beam502and upper beam504and opposite one another. In some embodiments, lower beam502and upper beam504have a length of about 12 inches to about 24 inches. In some embodiments, lower beam502and upper beam504have a length of about 18.25 inches. In some embodiments, vertical beams506a,506bhave a height of about 24 inches to about 40 inches. In some embodiments, vertical beams506a,506bhave a height of about 32.5 inches. In some embodiments, limit switches216a,216b,216c,216dare disposed on vertical beams506a,506b. Upper beam504may be positioned near drive unit213as illustrated. In some embodiments, elevator frame204comprises aluminum, stainless steel, titanium, or other like metals.

Sensor lift mechanism100may also comprise a backing plate508for supporting the various components of sensor lift mechanism100. Backing plate508may extend vertically from lower beam502upwards to upper beam504and laterally from first vertical beam506ato second vertical beam506b. In some embodiments, backing plate508is substantially rectangular and may comprise an array of cavities therethrough. In some embodiments, backing plate508comprises aluminum, stainless steel, titanium, or other like metals. As illustrated best with respect toFIG.1C, mounting assembly112may be connected to backing plate508for securing sensor lift mechanism100within tail cone108. Backing plate508may mount to elevator frame204via rivets, screws, bolts, clamps, or other mechanical fasteners.

Roller carriage assembly208may be substantially parallel to lower beam502and upper beam504and substantially perpendicular to vertical beams506a,506b. A first roller track512aand a second roller track512bprovide tracks configured for a roller to roll within thus maintaining alignment of roller carriage assembly208while the roller carriage assembly208is translating vertically. First roller track512amay be mounted to first vertical beam506aand second roller track512bmay be mounted to second vertical beam506b. By mounting roller tracks512a,512bseparately from vertical beams506a,506b, damage to roller tracks512a,512bmay not propagate to vertical beams506a,506b, enabling replacement of only the damaged roller track. In some embodiments, a first roller fitting510a, a second roller fitting510b, a third roller fitting510c, and a fourth roller fitting510dare mounted to roller carriage assembly208and comprise track rollers (seeFIG.6) configured to roll up and down within first roller track512aand second roller track512b, respectively.

In operation, as sensor lift mechanism100deploys sensor202, roller carriage assembly208may translate vertically down ball screw302via rollers in roller fittings510a,510b,510c,510drolling within first roller track512aand second roller track512b. In some embodiments, roller tracks512a,512bcomprise stainless steel (e.g., 17-4 Ph steel), aluminum, titanium, or alloys thereof to help withstand the high contact stresses induced by the track rollers. In some embodiments, roller tracks512a,512bcomprise a wear-resistant coating, such as an ion or gas nitride coating, a plasma electrolytic oxidation coating, carbide, ceramic, molybdenum, and the like, to increase the wear resistance of the track surface and to aid in withstanding high contact stresses that may be induced by the track rollers. In some embodiments, roller tracks512a,512bare bolted, screwed, or clamped to vertical beams506a,506bsuch that roller tracks512a,512bare easily removable and replaceable in case of damage. In some embodiments, ball screw302extends substantially through the center of roller carriage assembly208as will be discussed in further detail below with respect toFIG.6.

FIG.6illustrates a back, isometric view of roller carriage assembly208with attached roller fittings510a,510bfor some embodiments. In some embodiments, roller carriage assembly208comprises aluminum, stainless steel, titanium, or other like metals. In some embodiments, first roller fitting510aand third roller fitting510care attached to a first end602aof roller carriage assembly208, and second roller fitting510band fourth roller fitting510dare attached to a second end602bof roller carriage assembly208. In some embodiments, roller fittings510a,510b,510c,510dcomprise aluminum, stainless steel, titanium, or other like metals. A first track roller604amay be disposed on first roller fitting510a, a second track roller604bmay be disposed on second roller fitting510b, a third track roller604cmay be disposed on third roller fitting510c, and fourth track roller604dmay be disposed on fourth roller fitting510d. First track roller604amay be disposed on a first side wall605aof first roller fitting510a, substantially near the top of first roller fitting510a, towards drive unit213(seeFIG.5). Second track roller604bmay be disposed on second side wall605bof second roller fitting510b, substantially near the top of third roller fitting510c. Third track roller604cmay be disposed on third side wall605cof third roller fitting510cand substantially near the bottom of third roller fitting510c. Fourth track roller604dmay be disposed on fourth side wall605dand substantially near the bottom of fourth roller fitting510d. Side walls605a,605b,605c,605dmay extend outwards from roller carriage assembly208away from side wall110of tail cone108(seeFIG.1B). Track rollers604a,604b,604c,604dmay ride up and down roller tracks512a,512bas roller carriage assembly208translates vertically on ball screw302.

Attached to a back side of roller carriage assembly208as shown inFIG.6is first drag roller assembly606aand second drag roller assembly606b. First drag roller assembly606amay be mounted to first end602a, and second drag roller assembly606bmay be mounted to second end602b. First drag roller assembly606amay comprise a first drag roller608aand a second drag roller608b. First drag roller608amay be substantially parallel to first track roller604a, and second drag roller604bmay be substantially parallel to second track roller604b. Second drag roller assembly606bmay comprise a third drag roller608cand a fourth drag roller608d. Third drag roller608cmay be substantially parallel to third track roller604c, and fourth drag roller608dmay be substantially parallel to fourth track roller608d. Drag rollers608a,608b,608c,608dmay also translate up and down roller tracks512a,512bas roller carriage assembly208translates vertically on ball screw302.

Roller carriage assembly208may also comprise a ball nut swivel assembly610disposed on a top surface of roller carriage assembly208and substantially near the center of roller carriage assembly208. Ball nut swivel assembly610may comprise ball nut612for receiving ball screw302therethrough and swivel614configured to prevent rotational moments applied to ball nut swivel assembly610from damaging ball nut612and/or ball screw302. In some embodiments, ball nut612comprises a set of threads on an inner surface for mating to ball screw302. Ball screw302may be inserted through ball nut612and through opening616in roller carriage assembly208. Ball nut swivel assembly610may be configured to decouple ball nut612from any applied rotational deflections by the use of swivel614, thus preventing any rotational moments from being applied to ball screw302and ball nut612. When a rotational force is applied to ball nut swivel assembly610, swivel614may be configured to rotate instead of ball nut612or ball screw302, thus mitigating damage to ball nut612and ball screw302from the applied moment. Ball nut swivel assembly610may also serve to resist vertical forces applied to sensor lift mechanism100, such as the weight of sensor202and/or any downwards aerodynamic force from deploying sensor202into the airstream.

FIG.7illustrates a front, planar view of second drag roller assembly606bfor some embodiments. In some embodiments, first drag roller assembly606aand second drag roller assembly606bare substantially similar. Second drag roller assembly606bmay comprise a mounting plate702which may be mounted to second end602bof roller carriage assembly208by bolts704. In some embodiments, mounting plate702is fastened to second end602bvia rivets, screws, welds, or the like. Bolts704may also connect mounting plate702to swing arms706a,706b, with a first swing arm706aattached to third drag roller608cand a second swing arm706battached to fourth drag roller608d. Swing arms706a,706bmay pivot about bolts704in response to applied loads on sensor lift mechanism100. Drag rollers608c,608dmay also connect to roller adjuster arms708a,708bthat may be adjusted for appropriate length to keep drag rollers608c,608din contact with roller track512aas roller carriage assembly208translates vertically. The adjustability of drag rollers608c,608dmay account for the stack-up of fabrication and assembly tolerances of sensor lift mechanism100, thus ensuring sensor lift mechanism100operates effectively at all tolerance conditions. Keeping drag rollers608c,608din contact with second roller track512bduring operation reacts aerodynamic drag load, as drag rollers608c,608dare configured to withstand substantially high loads applied to sensor lift mechanism100during operation.

FIG.8illustrates an isometric view of the interface between first track roller604a, first drag roller608a, and roller track512afor some embodiments. In some embodiments, first roller track512ais sized to be slightly larger than the combined width of first track roller604aand first drag roller608asuch that first track roller604aand first drag roller608amay move within first roller track512ain response to applied forces without damaging first roller track512a. As shown, first track roller604amay ride up side wall802of roller track512awhile first drag roller608amay ride up back wall804of roller track512a. In some embodiments, first track roller604ais oriented substantially perpendicular to first drag roller608a. In some embodiments, side wall802and/or back wall804comprises titanium, stainless steel (e.g., 17-4PH steel), aluminum, or alloys thereof to resist damage from drag rollers608a,608b,608c,608d. In some embodiments, track rollers604a,604b,604c,604dand/or drag rollers608a,608b,608c,608dserve to resist longitudinal and/or latitudinal forces applied to sensor202due to drag when deployed into the air stream. Track rollers604a,604b,604c,604dand/or drag rollers608a,608b,608c,608dmay also resist any substantially longitudinal, lateral (e.g., inertial forces reacting about ball nut swivel assembly610), or vertical force applied to sensor202, such as an inertial loading force.

FIG.9illustrates drive system900for powering sensor lift mechanism100for some embodiments. As shown, drive system900comprises motor215coupled to gearbox214which powers the rotation of ball screw302. In some embodiments, motor215is a brushed or a brushless DC motor. In some embodiments, motor215is a 28V DC brushed motor. Motor215may comprise high altitude brushes for operating at high altitudes. Drive system900may also comprise ball nut612attached to ball screw302as described above and an upper bearing902disposed near drive unit213and a lower bearing mount904disposed substantially near the bottom of sensor lift mechanism100. In some embodiments, upper bearing902is connected to upper beam504to secure drive system900to elevator frame204. Lower bearing mount904may mount drive system900to lower beam502of elevator frame204. In some embodiments, ball screw302is configured to convert rotational movement into the linear motion of roller carriage assembly208. In some embodiments, various other linear motion systems, such as lead screws, a pulley system, a belt system, a rack and pinion system, a roller pinion, or the like may be used to translating roller carriage assembly208.

In some embodiments, ball screw302comprises a diameter of about 0.75 inches and a lead of about 0.5 inches. In some embodiments, ball screw302comprises a travel length of about 15 inches to about 26 inches such that sensor202travels about 15 inches to about 26 inches between the retracted position and the deployed position. In some embodiments, ball screw302comprises a travel length of about 18.5 inches. In some embodiments, ball screw302comprises an alloyed steel (e.g., 1045 alloy steel), aluminum, or titanium. In some embodiments, ball screw302is coated with chromium.

FIG.10Aillustrates a first planar view of gearbox214for some embodiments. As shown gearbox214may be coupled to motor215connected to an input spur gear pair1004. Motor casing1002may comprise stainless steel, aluminum, or titanium, and may be filled with grease for providing lubrication to the various gears within gearbox214. In some embodiments, spur gear pair1004comprises a gear ratio of 2.5/1. In some embodiments, spur gear pair is sealed with input seal1005. In some embodiments, input seal1005comprises a dual lip output shaft seal with a lubricant ring and a dust seal to prevent contaminants from entering gearbox214. In some embodiments, input seal1005comprises a single lip shaft seal. In some embodiments, input seal1005comprises a felt shaft seal, wherein the felt shaft seal comprises a felt washer. Spur gear pair1004may mate with worm1006as shown. In some embodiments, worm thrust bearings1008are provided on the ends of worm1006to resist thrust and rotation applied to worm1006. In some embodiments, worm thrust bearings1008are thrust and needle bearings. Worm1006may mate to a worm gear1010. In some embodiments, worm1006and worm gear1010prevent motor215from being backdriven, thus preventing sensor lift mechanism100from moving when motor215is off. In some embodiments, motor215, ball screw302, and limit switches216a,216b,216c,216drestrains sensor platform210in the vertical direction within isolator beams106a,106b. Preventing motor215from being backdriven also allows drive unit213to operate without a brake in some embodiments. In some embodiments, the worm1006and worm gear1010have a gear ratio of 20/1. In some embodiments, gearbox214comprises an overall gear ratio of 50/1. Gearbox214may also comprise a front plate gasket assembly1011to seal gearbox214. In some embodiments, gearbox214is filled with grease to provide lubrication to the various gears.

FIG.10Billustrates a second planar view of a gearbox214for drive unit213for some embodiments. As shown, worm1006may drive output shaft1012which may in turn drive ball screw302. Also illustrated inFIG.10Bis output shaft housing1014. In some embodiments, gearbox214is completely sealed via output shaft housing1014which may comprise a dual lip output shaft seal1016with a lubricant ring and a dust seal to prevent contaminants from entering gearbox214. In some embodiments, output shaft seal1016and input shaft seal1005are substantially similar.

Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of what is claimed herein. Embodiments have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from what is disclosed. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from what is claimed.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Not all steps listed in the various figures need be carried out in the specific order described.