Patent Publication Number: US-6986695-B2

Title: Method for attaching an empennage assembly to a model airplane

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application is a divisional application of copending U.S. patent application Ser. No. 10/690,065, filed Oct. 21, 2003, the entire content of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention pertains to assembly components for a model aircraft and, more particularly, to an empennage assembly that can be attached to a model airplane without the use of tools. 
     BACKGROUND OF THE INVENTION 
     When building a model of any kind, it is important to make sure that all of the various pieces of the model are aligned and securely attached to one another. This is important not only for aesthetic reasons but also to allow an operating model to function properly. One of the most important sections to assemble with respect to a model airplane is the empennage section. This section, which is also known as a tail assembly, includes flight control surfaces known as the vertical and horizontal stabilizers. 
     In order for an aircraft to properly fly, the empennage must be precisely aligned and attached to the fuselage. The need for this alignment is self-evident to anyone who has ever flown a real or model airplane, as the empennage and its component parts, the vertical and horizontal stabilizers, are critical to the control and stability of the aircraft. 
     The vertical stabilizer (also called the tail fin) includes the control surface known as the rudder. The rudder is used to control the aircraft&#39;s motion along the yaw axis and thus allow the nose of the aircraft to move left or right. The rudder is also important in aiding the pilot with maintaining what is known as balanced flight during a turn. This is because correct positioning of the rudder results in the tail of the aircraft directly following the line of flight of the nose of the aircraft through a turn, thereby eliminating a skidding or slipping of the aircraft. 
     The horizontal stabilizer controls the aircraft&#39;s motion along the pitch axis. This control surface allows the nose of the aircraft to pitch up or down so as to allow the airplane to climb or descend. Both the horizontal and vertical stabilizers work in conjunction with the ailerons on the wings to allow the airplane to move in all three axes (i.e., yaw, pitch and roll). Needless to say, if either the vertical or the horizontal stabilizer should separate from the aircraft, catastrophic results could occur. For this reason, it is important that a model aircraft have an empennage assembly that can be easily and securely fastened to the fuselage. In addition, for the model enthusiast, it is important to have an empennage assembly that can be attached to a model airplane by hand without the use of tools. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention relates to an empennage assembly for a model aircraft. In an embodiment, the empennage assembly includes a fuselage having a bottom portion with an opening, a housing is positioned in the opening in the bottom portion of the fuselage. The housing includes a first end defining an opening and a second end. A rod extends from an underside of a vertical stabilizer, and a horizontal stabilizer having a hole is aligned with the opening in the bottom portion of the fuselage, the housing and the rod, whereby the rod is positioned within the opening in the first end of the housing to secure the vertical and horizontal stabilizers to the fuselage. 
     The invention also relates to a method for attaching an empennage assembly to a model aircraft. In an embodiment, this method includes the steps of: (1) placing a horizontal stabilizer on a top portion of an aircraft fuselage so as to align a hole in the horizontal stabilizer with an opening in a bottom portion of the fuselage; (2) inserting a housing in the opening in the bottom portion of the fuselage and the hole in the horizontal stabilizer; (3) aligning a vertical stabilizer having a rod extending from an underside thereof with the hole in the horizontal stabilizer; (4) positioning the rod in the housing; and (5) securing the housing to the rod. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a model airplane utilizing the inventive empennage attachment device. 
         FIG. 2  is a perspective view of the empennage assembly showing a pair of rods and housings securing the vertical and horizontal stabilizers to the fuselage. 
         FIG. 3   a  is front view of the attachment device showing a rod positioned within a housing. 
         FIG. 3   b  is a top view of the housing. 
         FIG. 3   c  is a side view of the attachment device showing the rod positioned within the housing. 
         FIG. 4  is a front view of the rod used with the attachment device. 
         FIG. 5  is a perspective view of the housing used with the attachment device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention relates to an empennage assembly  10  for a model aircraft  100 , such as is shown in  FIG. 1 . In an embodiment, as shown in  FIGS. 1 and 2 , the assembly  10  includes a fuselage  12  that has an opening  14  in the bottom portion  16  near the rear of the airplane. A housing  18  is positioned in the opening  14 . The housing  18 , as shown in  FIGS. 3(   a ),  3 ( c ), and  5 , has a first end  20  that is open and a second end  22 . The assembly  10  also includes a vertical stabilizer  24  having a rod  26  extending from its underside  28  and a horizontal stabilizer  30  that includes at least one hole  32 . 
     When assembled, as shown in  FIG. 2 , the hole  32  in the horizontal stabilizer  30  is aligned with the opening  14  in the bottom portion  16  of the fuselage  12 . The rod  26  extending from the underside  28  of the vertical stabilizer  24  is then inserted through the hole  32  in the horizontal stabilizer  30  to engage the open end  20  of the housing  18  that has been inserted through the opening  14  in the bottom portion  16  of the fuselage  12 . The rod  26  is then secured within the housing  18 , thereby attaching the vertical and horizontal stabilizers  24 ,  30  to the fuselage  12 . 
     In an embodiment, the housing  18  may be a self-threading housing  18 . The rod  26  extending from the vertical stabilizer  24  may also be threaded. In another embodiment, as shown in  FIGS. 3(   a ),  3 ( c ) and  5 , the housing  18  may include a cylindrical portion  34  having an inner conic shape that is adapted to center the rod  26  in the cylindrical portion  34 . In still another embodiment, the second end  22  of the housing  18  forms a finger-grip bolt head, as shown in  FIG. 3(   b ). This finger-grip bolt head  22  allows the empennage assembly  10  to be secured to the fuselage  12  without the use of tools. 
     The rod  26  extending from the vertical stabilizer  24  has, in an embodiment, a first end  36  and a second end  38  with the first end  36  secured to the underside  28  of the vertical stabilizer  24 , as shown in  FIG. 2 . In an embodiment, as shown in  FIG. 4 , the first end  36  of the rod  26  has a first width w 1 , the second end  38  has a second width w 2  and the width w 1 , of the first end  36  is greater than the width w 2  of the second end  38 . This tapering of the rod  26  allows for it to be easily centered in the cylindrical portion  34  of the housing  18 . 
     The rod  26  may be a threaded rod  26  with both the first and second ends  36 ,  38  threaded. In an embodiment, the first end  36  of the rod  26  may be secured to the underside  28  of the vertical stabilizer  24  by any means known in the art, including, but not limited to, glue. The rod  26  may also be made of any known suitable material, including, but not limited to, steel. 
     In an embodiment, the opening  14  in the bottom portion  16  of the fuselage  12  may be one of a plurality of openings  14 . In such an embodiment, a housing  18  is positioned in each of the openings  14  and a plurality of rods  26  extends from the underside  28  of the vertical stabilizer  24 . The horizontal stabilizer  30  also includes a plurality of holes  32  and each of the holes  32  aligns with one of the housings  18  and one of the plurality of rods  26 . This embodiment allows for a more secure assembly in that the vertical and horizontal stabilizers  24 ,  30  are secured to the fuselage  12  at more than one point.  FIG. 2  shows a version of this embodiment in which two attachment points are used to connect the empennage assembly  10 . 
     The invention also relates to a method for attaching an empennage assembly  10  to a model aircraft. The method is comprised of the steps of: (1) placing a horizontal stabilizer  30  on a top portion  40  of an aircraft fuselage  12  so as to align a hole  32  in the horizontal stabilizer  30  with an opening  14  in a bottom portion  16  of the fuselage  12 ; (2) inserting a housing  18  in the opening  14  in the bottom portion  16  of the fuselage  12  and the hole  32  in the horizontal stabilizer  30 ; (3) aligning a vertical stabilizer  24  having a rod  26  extending from an underside  28  thereof with the hole  32  in the horizontal stabilizer  30 ; (4) positioning the rod  26  in the housing  18 ; and (5) securing the housing  18  to the rod  26 . 
     In an embodiment, the method further comprises the step of gluing the rod  26  to the underside  28  of the vertical stabilizer  24 . The housing  18  used in conjunction with the inventive method may be self-threading, and the rod  26  may also be threaded. In an embodiment, the method may also include the step of screwing the self-threaded housing  18  to the threaded rod  26 . 
     The invention also relates to a device for attaching an empennage assembly  10  to a model aircraft. The device is comprised of a housing  18  and a rod  26 , as shown in  FIGS. 3(   a )– 3 ( c ). The housing  18  may be a self-threading housing  18 , and the rod  26  may also be threaded. In an embodiment, the housing  18  includes a first end  20  having an opening, a cylindrical portion  34  and an inner conic shape that is adapted to center the rod  26  in the cylindrical portion  34 . One or both ends  36 ,  38  of the rod  26  may be threaded and a second end  22  of the housing  18  may be in the form of a finger-grip bolt head. 
     In an embodiment, the rod  26  may taper from the first end  36  to the second end  38 . The rod  26  may also be made of any suitable material, including, but not limited to, steel. 
     The use of the terms “a,” “an,” “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
     Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. It should be understood that the illustrated embodiments are exemplary only and should not be taken as limiting the scope of the invention.