Patent Publication Number: US-2022228904-A1

Title: Aircraft lifting devices with coupling adapters between jacks and load cells

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to aircraft lifting devices and more particularly relates to aircraft lifting devices with projections adapted to jack arms and cradles adapted to load cells. 
     BACKGROUND 
     It is sometimes necessary to lift a parked aircraft off the ground for various inspection and maintenance tasks. For example, maintenance tasks that involve removing the aircraft wheels typically requires lifting the aircraft. 
     The process of lifting the aircraft with at least one lifting device or jack is known as jacking the aircraft. During the jacking process, it is desirable to measure the weight supported by each jack for various reasons. For example, it may be desirable to know the weight distribution between the port and starboard wings of the aircraft to know whether the aircraft is tilted. Accordingly, a scale or load cell is typically placed between the ground and the aircraft to measure the weight supported by each jack. 
     One solution for connecting the load cell to the jack assembly is to use a threaded adapter between the jack and the load cell. Such a threaded adapter, however, may unscrew and become loose due to vibrations through the jack assembly during the lifting operation. When the threaded adapter is loosely connected there may be considerable side loading on the jack, resulting in damage to the jack assembly or costly damage to the aircraft. 
     Accordingly, it is desirable to provide a jack assembly that reduces the risk of damage to the aircraft and/or jacking assembly. In addition, it is desirable to provide a jacking assembly that includes an adapter that reduces the risks of side loading. Furthermore, other desirable features and characteristics will become apparent from the subsequent summary and detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. 
     BRIEF SUMMARY 
     An aircraft lifting assembly, an adapter for an aircraft lifting assembly, and a method of lifting an aircraft are disclosed herein. 
     In a first non-limiting embodiment, an aircraft lifting assembly includes a jack, a load cell, and a jack adapter. The jack includes an extendable arm having a distal end portion for exerting a force to lift an object. The distal end portion defines a cavity. The load cell is capable of measuring a weight supported by the jack during an aircraft lifting operation. The jack adapter couples the extendable arm to the load cell and includes a base portion, a cradle portion, and a projection. The base portion defines a jack arm support surface and a load cell support surface. The jack arm support surface opposes the distal end portion of the extendable arm and the load cell support surface opposes the load cell. The cradle portion extends from the base portion to circumscribe a portion of the load cell to secure the jack adapter to the load cell. The projection extends from the base portion into the cavity of the distal end portion of the extendable arm of the jack to secure the jack adapter to the extendable arm of the jack. 
     In another non-limiting embodiment, an adapter is for connecting an extendable arm of a jack to a load cell for aircraft lifting operations. The jack includes an extendable arm having a distal end portion defining a cavity. The load cell is capable of measuring a weight supported by the jack during an aircraft lifting operation. The adapter includes a base portion, a cradle portion, and a projection. The base portion defines a jack arm support surface and a load cell support surface. The jack arm support surface is configured to oppose the distal end portion of the extendable arm and the load cell support surface configured to oppose the load cell. The cradle portion extends from the base portion and is configured to circumscribe a portion of the load cell to secure the adapter to the load cell. The projection extends from the base portion to insert into the cavity of the distal portion of the extendable arm of the jack and secure the adapter to the extendable arm of the jack. 
     In another non-limiting embodiment, a method is for jacking an aircraft with a jack and a load cell, the jack including an extendable arm, the extendable arm having a distal end portion for exerting a force to lift an object, the distal end portion defining a cavity, the load cell capable of measuring a weight supported by the jack during an aircraft lifting operation. The method includes inserting a projection of a jack adapter into the cavity of the extendable arm to couple the extendable arm to the load cell. The method further includes positioning a base portion of the jack adapter such that a jack arm support surface of the base portion opposes the distal end portion of the extendable arm. The method further yet includes positioning the load cell into a cradle portion of the jack adapter that extends from the base portion, the positioning of the load cell such that the cradle portion circumscribes a portion of the load cell to secure the jack adapter to the load cell. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and 
         FIGS. 1-2  are perspective views of an aircraft lifting assembly in accordance with some embodiments of the present disclosure; 
         FIGS. 3-4  are perspective views of a load cell adapter of the aircraft lifting assembly illustrated in  FIGS. 1-2 ; and 
         FIG. 5  is a flow diagram illustrating a non-limiting embodiment of a method ofjacking an aircraft using a jack and a load cell in accordance with the teachings disclosed herein. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. 
     An improved aircraft lifting assembly is disclosed herein. In a non-limiting embodiment, the aircraft lifting assembly includes a load cell adapter that nests into main wing aircraft jacks and nose aircraft jacks. When a male section of the load cell adapter is installed into a cavity on the jack, a locking pin may be installed through the jack and the male section of the load cell adapter to further protect against adapter displacement from the jack. The load cell adapter holds and cradles load cells for weight and balance procedures. A cutout notch may be included to accommodate load cell communication and/or power plugs. In some embodiments, the load cell adapter is circular, cup shaped, and wraps around the entire load cell using a wide base to protect against tipping of the load cell. 
     A greater understanding of the aircraft lifting assembly, the load cell adapter, and a method of lifting an aircraft may be obtained through a review of the illustrations accompanying this application together with a review of the detailed description that follows. 
       FIGS. 1-2  are side views illustrating an aircraft lifting assembly  100  in use on an aircraft  102 . Aircraft  102  may comprise any type of aircraft including, without limitation, a subsonic aircraft, a supersonic aircraft, a propeller driven aircraft, a jet powered aircraft, a commercial airliner, a private business jet, a cargo aircraft, a military aircraft, and any other type of aircraft in which it is desirable to lift a stationary aircraft off the ground for maintenance or inspection purposes. Additionally, although the lifting assembly of the present disclosure is being described and explained in the context of its application for lifting an aircraft, it should be understood that the lifting assembly of the present disclosure is not limited to lifting aircraft. Rather, the lifting assembly of the present disclosure may be used on any type of vehicle including, but not limited to, automotive vehicles, surface and sub-surface watercraft, and spacecraft. Furthermore, the lifting assembly is not limited to use in vehicles and may be employed in other applications unrelated to vehicles such as, and without limitation, in the construction and manufacturing industries. In still other applications, the lifting assembly of the present disclosure may be employed in any industry and/or application where it is desirable to lift heavy objects while measuring the force applied to the object. 
     The aircraft  102  has a plurality of jacking positions designated by the manufacturer of the aircraft  102 .  FIGS. 1-2  illustrate the lifting assembly  100  in use on a main wing lifting position for inspection and maintenance operations. It should be appreciated that the lifting assembly  100  may be used in any suitable lifting position or other suitable lifting location without departing from the scope of the present disclosure. 
     The aircraft lifting assembly  100  is used between a ground or other support surface and the aircraft  102  for jacking the stationary aircraft  102  during maintenance and inspection procedures. The aircraft lifting assembly  100  includes a jack  110 , a load cell  112 , a load support plate  114 , and a load cell jack adapter  116 . Additional or fewer components may be included in any particular implementation without departing from the scope of the present disclosure. 
     The jack  110  is a mechanical lifting device used to apply great forces or lift heavy loads. In the example provided, the jack  110  is a screw jack. Other jack types may be used without departing from the scope of the present disclosure. The jack  110  includes an extendable arm  200  that protrudes from a jack base  202 . 
     The extendable arm  200  translates into and out of the base  202  during operation. The extendable arm  200  has a distal end portion  204  for exerting a force to lift an object. For example, as the extendable arm  200  translates out of the base  202 , the weight of the object presses on the distal end portion  204 . The lifting assembly  100  resists and lifts the weight by transferring lifting forces from the ground surface to the base  202 , from the base  202  to the extendable arm  200 , from the distal end portion  204  to the jack adapter  116 , from the jack adapter  116  to the load cell  112 , from the load cell  112  to the load support plate  114 , and from the load support plate  114  to the aircraft  102 . 
     The distal end portion  204  defines a top surface  210 , a cavity  212 , and a jack arm pin aperture  213 . The top surface  210  opposes a jack arm support surface of the jack, as will be described below. In the example provided, the top surface  210  is flat and level when the base  202  is level. The cavity  212  has cavity walls that are cylindrical and coaxial with an outer surface of the extendable arm. It should be appreciated that the cavity  212  may have other shapes without departing from the scope of the present disclosure. The jack arm pin aperture  213  is a bore hole through which a locking pin may be inserted, as will be described below. 
     The load cell  112  is a weight measuring device that is capable of measuring a weight supported by the jack  110  during an aircraft lifting operation. In the example provided, the load cell  112  has a cylindrical shape with a diameter that is larger than the diameter of the extendable arm  200 . The load cell  112  defines a bottom surface  220  opposing a load cell support surface of the jack adapter that will be described below. 
     The load support plate  114  couples with the load cell and contacts the aircraft  102 . The load support plate  114  distributes the force of lifting the aircraft  102  according to the design of the jacking position. For example, the load support plate  114  may have a contoured support surface that matches a shape of the aircraft  102  and distributes weight across an area that is selected based on a safe loading pressure at the jacking position. 
     Referring now to  FIGS. 2-3 , and with continued reference to  FIGS. 1-2 , the load cell jack adapter  116  is illustrated in perspective views in accordance with some embodiments of the present disclosure. The load cell jack adapter  116  secures the load cell  112  to the extendable arm  200  to reduce a risk of tipping or side loading of the lifting assembly  100 . 
     The jack adapter  116  includes a base portion  230 , a cradle portion  232 , a projection  234 , and a locking pin  236 . In some embodiments, the base portion  230 , the cradle portion  232 , and the projection  234  are monolithic pieces of metal. For example, the base portion  230 , the cradle portion  232 , and the projection  234  may be machined from a single piece of steel or aluminum stock on a mill or lathe. 
     The base portion  230  is disposed between the cradle portion  232  and the projection  234  and defines a jack arm support surface  240  and a load cell support surface  242 . The jack arm support surface  240  opposes the distal end portion  204  of the extendable arm  200 . The jack arm support surface  240  is larger than the top surface of the distal end  204  of the extendable arm  200  of the jack. Accordingly, the load from the aircraft  102  is distributed across substantially the entire top surface of the distal end  204  and pressures are minimized. Additionally, the large jack arm support surface  240  provides a wide base to restrict tipping of the jack adapter  116  off of the extendable arm  200 . 
     The load cell support surface  242  opposes the load cell  112 . The load cell support surface  242  is larger than the bottom surface of the load cell  112 . Accordingly, the load from the aircraft  102  is distributed across substantially the entire bottom surface of the load cell  112  to the base portion  230  of the jack adapter  116 . Additionally, the wide base of the load cell support surface  242  restricts tipping of the load cell  112  off of the jack adapter  116 . 
     The cradle portion  232  extends away from the base portion  230  to circumscribe a portion of the load cell  112  and secure the jack adapter  116  to the load cell  112 . In the example provided, the cradle portion  232  is a wall portion that defines an electrical connector pass-through portion  244  configured to permit an electrical connection to the load cell  112 . 
     The cradle portion  232  has a cradle shape that is based on the load cell shape of the load cell  112 . For example, the walls of the cradle portion  232  may have a cylindrical inner surface that is shaped substantially the same as an outer surface of the load cell  112  is shaped. As used herein, the term “substantially the same as” means that the walls are larger by an amount that permits easy insertion of the load cell  112  after accounting for manufacturing tolerances. 
     The projection  234  extends from the jack arm support surface  240  of the base portion  230  into the cavity  212  of the distal end portion  204  of the extendable arm  200  of the jack  110  to secure the jack adapter  116  to the extendable arm  200  of the jack  110 . 
     The projection  234  has a projection shape that is based on a cavity shape of the cavity  212 . For example, the cavity  212  and the projection  234  may have similar circular profiles, square profiles, or profiles of any other suitable shape that are substantially the same size. In the example provided, the projection shape is substantially the same as the cavity shape. 
     The projection  234  defines a projection pin aperture  246  through which the locking pin  236  may be inserted. Projection pin aperture  246  is a bore hole that extends through the projection  234  perpendicular to a longitudinal direction of the projection  234 . 
     The locking pin  236  may be inserted to extend through the jack arm pin aperture  213  and through the projection pin aperture  246  to restrict rotation of the jack adapter  116  within the extendable arm  200  of the jack  110 . The locking pin  236  includes a locking feature  250  that is released by a release button  252  on a handle of the locking pin  236 . For example, the locking feature  250  may be a ball bearing biased outwards by a mechanism that ceases to bias the ball bearing in response to depression of the release button  252 . 
     Referring now to  FIG. 5 , and with continued reference to  FIGS. 1-4 , a method  300  of jacking an aircraft with a jack and a load cell is illustrated in flow diagram form. The sequence of tasks illustrated and described below may be changed without departing from the scope of the present disclosure. For example, the jack adapter may be assembled with the jack and the load cell before positioning the assembly beneath a jacking position. 
     Task  310  positions a jack beneath a jacking location on an aircraft. The jack includes an extendable arm. The extendable arm has a distal end portion for exerting a force to lift an object. The distal end portion defining a cavity. The load cell is capable of measuring a weight supported by the jack during an aircraft lifting operation. For example, task  210  may position the jack  110  and the load cell  112  beneath the aircraft  102 . 
     Task  312  inserts a projection of a jack adapter into a cavity on an extendable arm of the jack. For example, task  312  may insert projection  234  into cavity  212  of extendable arm  200  of the jack  110 . 
     Task  314  inserts a locking pin through the extendable arm and the projection. For example, task  314  may insert the locking pin  236  through the jack arm pin aperture  213  and through the projection pin aperture  246  to restrict rotation of the jack adapter  116  within the extendable arm  200  of the jack  110 . 
     Task  316  inserts a load cell into a cradle of the jack adapter. For example, task  316  may insert load cell  112  into cradle portion  232  of jack adapter  116 . 
     Task  318  aligns a connector port of the load cell with a cutout in the cradle. For example, task  318  may align pass-through portion  244  of jack adapter  116  with an electrical connection port of the load cell  112 . Task  320  electrically couples a cable with the connector port through the cutout. For example, the cable may be inserted into the connection port of the load cell  112  through the pass-through portion  244 . 
     Task  322  raises the extendable arm of the jack to contact and lift the aircraft. For example, task  322  may operate the jack  110  to lift the aircraft  102 . 
     While at least one exemplary embodiment has been presented in the foregoing detailed description of the disclosure, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the disclosure. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the disclosure as set forth in the appended claims.