US 3883092 A
There is disclosed a free flying glider having a wing construction of a positive double dihedral configuration and a tail construction including a vertical stabilizer disposed below a line through the apex of the wing construction and parallel to the longitudinal axis of the fuselage.
Description (OCR text may contain errors)
United States Patent 1191 Ditto 1 GLIDER  Inventor: Ralph L. Ditto, 2205 Paul Minnie,
Santa Cruz, Calif. 95062  Filed: Nov. 14, 1973 [21 Appl. No.: 415,807
 U.S. Cl. 244/16; 46/79; 244/91;
244/154  Int. Cl B646 31/02; A63h 27/00 [58} Field of Search 244/16, 154, 87, 13. 15,
244/91; 46/79, 80. 81; D34/15 HH; D12/7l  References Cited UNITED STATES PATENTS 4/1911 Chalfant 244/16 5/1932 lkerman.. 244/154 2,136,717 11/1938 Waldockm, 244/154 2,778,154 1/1957 Dauwe 46/79 X 2,784,524 3/1957 Jackle 46/79 3,157,960 11/1964 Schultz et al D34/l5 HH X 3,363,862 1/1968 1 May 13, 1975 7/1969 Street 46/81 OTHER PUBLICATIONS American Aircraft Modeler, Volume 69, No. 5, November, 1969, p. 33.
American Aircraft Modeler, Volume 71), No. 5, May, 1970, pp. 2226.
Primary Examiner-Trygve M. Blix Assistant Examiner-Barry L. Kelmachter Attorney, Agent, or Firm-Phillips, Moore, Weissenberger, Lempio & Strabala  ABSTRACT There is disclosed a free flying glider having a wing construction of a positive double dihedral configuration and a tail construction including a vertical stabilizer disposed below a line through the apex of the wing construction and parallel to the longitudinal axis of the fuselage.
4 Claims, 4 Drawing Figures GLIDER BACKGROUND OF THE INVENTION This invention relates to free-flying gliders capable of sustained flight of long duration. In particular, this invention relates to such gliders having improved aerodynamic characteristics which provide improved glider lift and control during flight.
Numerous airplane constructions on either a full or minature scale which are designed for captive or free flight are well-known in the art. Examplary of such constructions are those described in US. Pat. Nos. 1,1 12,126 to Emmons; 1,374,000 to Dunn; 1,378,193 to Petty; 1,420,193 to Howard; 1,518,621 to Wenk; 1,652,519 to Dowd; 2,432,297 to Dowd; 2,599,957 to Walker; 2,778,154 to Dauwe; 3,009,670 to Williams et al.; and 3,366,354 to Sterba.
It has been found that many such prior art constructions are unsatisfactory in terms of control, lift, and other flight characteristics. Additionally, these constructions are often complicated frequently providing refinements which are elaborate but which do not appreciably increase the aerodynamic efficiency of the glider or other airplane.
SUMMARY AND OBJECTS OF THE INVENTION The invention provides a glider construction including a wing construction having a positive double dihedral configuration and a tail construction including a vertical stabilizer and a horizontal stabilizer disposed below a line through the apex of the wing line and parallel to the longitudinal axis of the fuselage. The vertical stabilizer extends above and below the fuselage, with the lower portion thereof also serving as a tail skid. The horizontal stabilizer is affixed preferably at a slight angle of declination, and includes an elevator, or preferably, a fixed trim tab at a slight angle of declination.
These elements and their respective angulations are positioned according to the specific construction desired, and provide a glider having improved aerodynamic efficiency with superior lift and control characteristics.
It is therefore an object of this invention to provide a free-flying glider of improved aerodynamic efficiency.
It is another object of this invention to provide a glider having an improved wing construction for increased aerodynamic efficiency.
It is a further object of this invention to provide a free-flying glider of improved aerodynamic efficiency which has particular ultility as a toy.
Other objects and advantages of this invention will be apparent from the following description and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the glider of this invention;
FIG. 2 is a front view of the glider of FIG. 1 illustrating the wing configuration;
FIG. 3 is a side view of the glider of FIG. 1; and,
FIG. 4 is a bottom view of the glider of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the drawings, the glider of this invention, generally indicated at 10, is illustrated in its simplest form as a free-flying minature glider which is typically hand-launched, preferably with the assistance of a rubber band or other mechanical aid in a conventional manner.
The glider 10 includes a wing construction 11, forming a continuous surface, as shown in FIG. 1. In the preferred embodiment illustrated, the wing 11 includes left and right centerwing portions 12 and 13, respectively, and left and right wingtip portions 14 and 16, respectively, having a positive double dihedral configuration. As best shown in FIG. 2, the centerwing portions 12 and 13 each have a positive dihedral angle, and the wingtip portions each have a positive dihedral angle of slightly greater degree. In an alternate embodiment (not illustrated), the configuration of the wing 11 comprises centerwing portions 12 and 13 in one plane, and wingtip portions 14 and 16 each having a dihedral angle.
The glider 10 further includes a tail construction generally indicated at 17 and best shown in FIG. 3. The tail 17 includes a first vertical stabilizer 18 extending above and a second vertical stabilizer extending below, below the fuselage 19, and a horizontal stabilizer 21 provided with a trim tab 22 in a fixed angle of declination (i.e., angled downwardly) with respect to the horizontal stabilizer. Alternately, it may be advantageous in some applications to include an elevator in place of the trim tab 22.
The horizontal stabilizer 21 is disposed below the fuselage and a line through the apex of the wing 11 parallel to the longitudinal axis of the fuselage 19, preferably at a slight angle of declination with respect to this axis. The lower vertical stabilizer 23 is spaced aft of stabilizer 18 also functions as a tail skid, and may include landing gear, if desired.
The preferred aerodynamic characteristics of the glider 10 are obtained by the specified configuration and appropriate balance of the glider components. For example, in the embodiment illustrated, a satisfactory angle of dihedral of the centerwing (A is between 5 and 10 and a satisfactory angle of the dihedral of the wingtip is of about the same order with respect to the center wing. The total angle A; would preferably be about twice that of A The double dihedral is found to give greater lift as well as to improve anti-roll stability. The stabilizer elements 18 and 21 are positioned with respect to the other glider components to impart the desired directional stability to the glider, and the trim tab set to obtain the desired balance according to the requirements of a particular construction.
The glider 10 is preferably formed from balsa wood or similar lightweight durable construction material, with the exception of the fuselage, which is preferably formed of a strong material to permit launching of the glider with mechanical aids. In some applications, however, a very lightweight fibrous material such as bond paper may be utilized, or in other applications lightweight durable materials other than balsa wood may be advantageous.
In operation, a rubber band or similar mechanical aid is inserted in the launching notch 24 in the nose of the glider, and stretched for releasing the glider in a conventional manner. If desired, the glider may be hand launched without mechanical aid. Balance of the glider may require slight adjustment, in which case it may be adjusted by a weight toward the forward end of the fuselage 19 such as a clip 26, positioned as required to correct balance. Other balancing means such as modeling clay may also effectively be used to adjust the balance.
vAlthough the invention has been described with respect to the illustrated embodiment, this embodiment is presented only by way of example and is not intended to limit the invention thereto. Equivalent embodiments which are within the perview of the invention will be apparent to those skilled in the art, and the invention includes all such modifications except as limited by the appended claims.
What is claimed is:
l. A glider having a fuselage connected below a wing assembly including a continuous surface wing construction comprising right and left centerwing portions and right and left wingtip portions, each of said centerwing portions having positive dihedral with respect to a horizontal plane and said wingtip portions having positive dihedral with respect to said horizontal plane that is twice that of said centerwing portions; and
a first vertical stabilizer extending above said fuselage and a second vertical stabilizer extending below the fuselage behind said first stabilizer, and a horizontal stabilizer disposed aft of said first stabilizer and intersecting the second vertical stabilizer and disposed in a plane below a line through the apex of said wing construction parallel to the longitudinal axis of said fuselage.
2. The invention of claim 1 wherein the dihedral of said centerwing portion is 5 and the dihedral of said wingtip portions is 10.
3. The invention of claim 2, wherein said horizontal stabilizer is set at an angle of declination with respect to said axis.
4. The invention of claim 3, wherein said horizontal stabilizer includes a trim tab set at an angle of declination with respect to said horizontal stabilizer.