Patent Abstract:
A tool for installing a pitot tube cover on an elevated pitot tube of an aircraft includes an adjustable light weight support pole carrying a brace for carrying and guiding the cover during installation over the pitot tube, wherein the brace includes upwardly projecting pliable pins for engaging tabs on the cover and a cross shaft for guiding movement of the cover into alignment and registration with said pitot tube.

Full Description:
FIELD OF THE INVENTION 
     The present invention relates to a tool for installing pitot tube covers on aircraft. 
     BACKGROUND OF THE INVENTION 
     Pitot static tubes, used on aircraft for measuring speed and altitude, are sensitive and delicate, and thus prone to damage during installation, maintenance, and storage. To limit such damage and contamination, pitot tube covers are typically installed during any appreciable layover to prevent dust, particulates, water, and other foreign matter from entering the probe ports. 
     On smaller planes, the covers may be readily manually installed and removed. On larger planes, where the pitot tubes are located at high elevations, tools have been developed to assist in the installation and removal, in preference to ladders or other forms of assists. The tools, however, have demonstrated certain limitations. First, the tools tended to be heavy and somewhat unwieldy. Second, the construction materials presented a potential for craft damage upon inadvertent impact. Third, the component parts had the potential for breakage and/or separation during use, presenting unwanted debris on the operational surfaces. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved pitot tube cover installation tool wherein the unit is lightweight with positively captured parts that may be safely guided onto the pitot tubes at varying elevations. The tool comprises an adjustable lightweight aluminum support pole having an attached all aluminum head assembly at the top that carries a cover into guided alignment with the pitot tube. The component parts are affirmatively and redundantly captured to prevent separation and formed of materials limiting aircraft damage upon inadvertent impact. 
     In one aspect, the invention provides a tool for installing and removing a pitot tube cover from a pitot tube at an elevated position on an aircraft wherein said cover includes a body having an annular opening to an internal cavity for receiving the pitot tube and a pair of laterally spaced tab members on said body of said cover, the tool including an adjustable support member providing for selective vertical length adjustment between a retracted and an extended position, said support member including telescoping tubular upper and lower members wherein said upper member includes an upper cylindrical socket, a base member formed of planar light weight material; a cylindrical hub attached to a lower surface of said base member and received in said socket of said support member. said base member including a pair of forwardly projecting laterally spaced arms each having an aperture in a frontal portion thereof; a pair post members having cylindrical shafts extending through said apertures and an enlarged cylindrical bases connected to lower surfaces of said arms, said shafts having an enlarged annular swaged section at the top surfaces of said arms mechanically preventing removal over said post members, said post members being formed of soft aluminum, said post members engaging said tab members of said cover for shifting said cover relative to said pitot tube upon guided movement of said support member; a transverse opening through said socket and said hub; a cylindrical shaft member extending through said opening and having outer ends symmetrically disposed with respect thereto, said ends providing alignment assistance as said cover is guided into alignment with said pitot tube; a fastener attaching said shaft member to said hub; and upwardly extending laterally spaced bracket members limiting movement of said body of said cover during insertion on said pitot tube. The tool may further include aligned apertures formed through said socket, said hub and said rod, and said fastener includes a threaded shaft extending through said aligned apertures thereby fixedly connecting said base member to said support pole. The tool may further include bracket members that are V-shaped having inwardly diverging walls for restraining horizontal and vertical movement of said body of said cover during installation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features and advantages of the present invention will become apparent upon reading the following description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a partial perspective view of a pitot tube cover installation tool in accordance with an embodiment of the invention; 
         FIG. 2  is a top view showing the installation tool inserting a cover over a pitot tube; 
         FIG. 3  is a side view showing the installation tool inserting the cover over a pitot tube; 
         FIG. 4  is a side view of the installation tool; 
         FIG. 5  is side view of the support pole for the installation tool; 
         FIG. 6  is top view of the installation head base; 
         FIG. 7  is a side view of the installation head base; 
         FIG. 8  is a front view of the installation head base; 
         FIG. 9  is a side view of the contact rod; 
         FIG. 10  is a side view of the installation head and tool; 
         FIG. 11  is a top view of the installation head and tool; and 
         FIG. 12  is a front view of the installation head and tool. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to drawings,  FIGS. 1 through 3  show an installation tool  10  for installing and removing a pitot tube cover  12  from the pitot tube  14  of an aircraft  16 . The tool  10  is particularly useful for larger aircraft wherein the pitot tubes are disposed at elevations on the aircraft precluding manual installation of the cover without supplemental assists such as ladders. 
     The cover  12  is generally characterized by a tubular sleeve  20  of a temperature resistant fiber, closed at closed at a tail end  22  and having an annular opening at the head end  24  to an internal cavity for receiving the inserted pitot tube  14 . The present invention is particularly beneficial for pitot tube covers wherein the cover opening has a sliding compressive fit with the pitot tube forming the primary retention force for the cover. For assisting installation, side loops  26  are provided at the head end  24 . For assisting removal, and end loop  28  is provided at the tail end  22 . Examples of suitable covers in the present invention are disclosed in U.S. Pat. Nos. 5,127,265 to Williamson, and 6,412,343 and 6,901,793 to Jefferson. 
     Referring to  FIG. 1 , the tool  10  includes an installation head  30  mounted on an adjustable light weight support pole  32 . As shown in  FIGS. 4 and 5 , the pole  32  includes a tubular lower section  34  telescopically receiving a tubular upper section  36 . The sections are releasably coupled at a clutch lock  38 . The length may be adjusted at the lock to provide adjustability from a retracted position to an extended position. It has been determined that an adjustable length of between about 6 to 13 feet will allow personnel to install the covers on all current large aircraft. A non-slip surface  39  may be applied to the lower section. The support pole is formed of a light weight material, preferably anodized Grad 6063-T6 aluminum. 
     Referring to  FIGS. 6-8 , the installation head  30  includes a base plate  40  attached to a cylindrical lug or hub  42 . The hub  42  has a sliding fit with an upwardly opening distal socket  44  in the upper pole section  36 . A main cross hole  46  is coaxially formed in the lug  42  and socket  44  of the upper pole section. A cylindrical contact rod  48  is inserted through the cross hole  46  and has outer ends  49  extending symmetrically outwardly therefrom. A minor cross hole  50  is formed transverse to the main cross hole in the lug  42   46 , the socket, and the center of the contact rod  48 . A threaded fastener assembly  52  is inserted through the cross hole  50  and fastened to secure the installation head  30  and contract rod  48  on the support pole  32 . 
     The base plate  40  is formed of a planar light weigh material, preferably 5052-H32 aluminum. The base plate  40  includes a C shaped frontal end  60  having arcuate arms  62  and a rectangular rear end  64  having a pair of laterally spaced, upwardly extending V-shaped brackets  66  at the sides thereof. The brackets have inwardly diverging surface for horizontally and vertically orienting the cover body under prevailing wind conditions. Referring to  FIG. 13 , the arms  62  terminate at apertures  68 . A pair of cylindrical posts  70  are mounted on the arms with shafts  72  extending upwardly through the apertures and enlarged heads  74  engaging the bottom surface of the arms. The posts  70  are attached in two modes. First, the heads  70  are tack welded at  76  to the arms. Second, the shafts  72  are mechanically swaged to create and enlarged annulus  78  at the top surface providing a mechanical lock against separation of the posts in the event of tack weld failure. Such localized swaging may be provided by counter bored die  80 , shown in dashed lines, inserted over the shaft  72  and impacted to locally form the annulus. This is facilitated by the use of a soft aluminum, such as 1100F aluminum, for the pins. The soft aluminum does not pose a penetrating, denting or scratching potential to the aircraft skin in the event of inadvertent impact. Further, the pins readily deflect upon any impact, but may be manually repositioned repeatedly without fracture. The posts  70  are laterally spaced slightly greater than the free width of the head end of the cover such that when the side loops of the covers are inserted thereover, the side loops during installation provide a primarily axially directed force minimizing distortion of the annular opening. The brackets are positioned to engage the sides of the cover to maintain axial alignment of the cover opening not withstanding prevailing wind conditions. 
     For installation, the cover is placed on the base  40  and the posts  70  inserted in the side loops  26  on the pitot tube cover  12 . The body of the cover is supported by the base plate with the brackets  66  providing side restraint for orienting the cover. For installation, the tool is moved forwardly toward the pitot tube  14  with the inboard end of the contact rod  48  riding against the aircraft exterior surface  86  to establish alignment. The tool movement is continued until the cover is fully installed over the pitot tube, at which time the tool is lowered withdrawing the posts from the side loops. For removal, the end loop  28  on the cover is engaged by one of the posts and urged rearwardly to remove the cover from the pitot tube. 
     Having thus described a presently preferred embodiment of the present invention, it will now be appreciated that the objects of the invention have been fully achieved, and it will be understood by those skilled in the art that many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the sprit and scope of the present invention. The disclosures and description herein are intended to be illustrative and are not in any sense limiting of the invention, which is defined solely in accordance with the following claim.

Technology Classification (CPC): 1