US 3388651 A
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Description (OCR text may contain errors)
June 18, 1968 s, AXELROD 3,388,651
COVERING FOR AIRPLANES AND METHOD FOR APPLYING SAME Filed Jan. 28, 1966 AT TO R NEYS 3,388,651 CUVERENG EUR AIRPLANES AND METHGD FR APPLYlNG SAME Sidney Axelrod, Chicago, lll., assigner to Top Flite Models, lac., Chicago, lll. Filed San. 28, 1966, Ser. No. 523,599 Claims. (tCl. lion-'76) ABSTRACT F THE DiSCLGSURE A covering Vfor airplane frames wherein a layer of plastic film has a layer of adhesive bonded thereto for applying the plastic material to the frame. In addition, the adhesive may be colored to impart said color to the airplane while the coloring itself is protected by the plastic. There is also disclosed a method for applying the lilm with the adhesive bonded thereto by adhering and shrinking the same to the frame through the application of heat and resultant cooling.
This invention relates to a covering for airplanes and more particularly relates to a covering for model airplanes and the method for applying the same. l
Model airplanes which are built for the sport of flying, normally comprise an airplane frame covered by a light weight material. Heretofore, to properly cover these model airplanes required a great deal of skill andthe expenditure of many hours of effort. For example, in a commonly used prior method a thin light material of paper or silk was placed over the frame, then wetted to cause shrinkage, after which many layers of dope or lacquer were placed over the material. Moreover, before one of these layers were placed on another, it was dried and afterward sanded to the proper smoothness. After this was completed, it was still necessary to provide a finish over the airplane. Even the most skilled found that the aforementioned method had many objectionable features. The main objection, however, was the time involved in properly covering and finishing the airplane frame. lIn fact, many who were interested in the flying or competitive aspect of a model airplane hobby were discouraged from pursuing the same due to the time factor in fabricating the airplane models.
Another objection `of the aforementioned method was that the thin light material initially applied over the frame was easily torn or otherwise damaged. Furthermore, the wetting of the material frequently caused uncontrollable shrinkage which often developed into wrinkles that were not usually able to be completely smoothed out. Hence, the material did not have suflicient tautriess in all directions. Moreover, when applying the layers of dope or lacquer weight imbalances invariably resulted due to the uneven amounts of dope or lacquer which were used in filling in the valleys of the wrinkles in the material. This appreciably affected the airplanes flying performance.
It is therefore a primary object of this invention to provide a model airplane covering that is capable of being applied over an airplane frame at a substantial reduction of the time which was heretofore necessary.
It is another object to provide a model airplane covering that is capable of providing sufhcient tautness in all directions.
lt is a further object to provide an airplane covering that is not susceptible to the occurrences of weight imbalances when applied over the frame.
A `defect in prior model airplane coverings was the susceptibility of the same to lose its bond with the frame when fuel would seep into the area between the outer surface of the covering and the frame. For some coverings, 'access to States Patent 0 the inside was through the lap over joint which is the area where an edge of a portion of the covering lies ori a surface of another portion of :the covering. For other coverings which had successive layers of dope, the fuel would eat its way through the paint finish and the dope. Still a further defect of some of the prior model airplane coverings was the tendency of the same to develop a large tear from even the slightest puncture.
It is therefore another primary object to provide a covering for model airplanes that affords a sufficiently bonded lap over joint to prevent the seepage of fuel between the plastic layer and the frame.
It is still another primary feature to provide a covering which is securely bonded to the frame of the model airplane whereby any damage to the covering is kept localized and does not spread to other areas.
Heretofore, the applying of a finish to the airplane for the final step before the completion of the covering process, was also a time consu-ming task. Furthermore, when a plastic was suggested for use as a possible model airplane covering, a coloring problem immediately arose due to the difhculty in applying paints to such coverings.
It is therefore another primary object of this invention to provide a covering for model airplanes which includes a plastic layer of material and does not require painting or a color finishing step in order to impart coloring to the covering.
It is a primary feature of this invention to provide a model airplane covering which comprises a plastic outer layer and a pressure sensitive inner adhesive layer for adhesively associating the plastic to the airplane frame.
It is another primary feature of the invention to shrink and bond a plastic material to the contours of the frame of the model airplane.
It is a further feature to insert colored material between the outer exposed layer of the covering of the airplane and the airplane frame.
It is still a further feature to provide an airplane covering that is also adaptable as a joint or hinge for the various movable parts of the model airplane.
For the purpose of facilitating an understanding of my invention, I have illustrated in the accompanying drawing a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, my invention, its mode of construction, assembly and operation, and many of its advantages should be readily understood and appreciated.
Referring to the drawing in which like characters of reference indicate corresponding or similar parts throughout the several figures of the drawing:
FIGURE l is a perspective view of a model airplane ernbodying the principles of the invention;
FIGURE 2 is a wing of a model airplane with portions of the covering cut away to show the wing structure of the frame;
FIGURE 3 is a sectional view showing a layer of pressure sensitive adhesive material attached between a layer of plastic material and a layer of release paper;
FIGURE 4 is a fragmentary sectional view showing the adhesive layer attached to the plastic layer and spaced from a section of the frame of the model airplane;
FIGURE 5 is an enlarged fragmentary sectional view showing the adhesive layer attached to a porous frame and with portions of the adhesive layer extending into the pores of the frame;
FIGURE 6 is an enlarged fragmentary View of the tail of the model airplane in FIGURE l, and showing in phantom movable parts thereof in an angularly displaced position;
FIGURE 7 is a sectional view taken substantially on the plane of the line '7 7 in FIGURE 6, viewed in the 3 direction indicated, and showing the model airplane covering acting as a joint to permit movement of one section from another; and
FIGURE 8 is a fragmentary enlarged sectional view illustrating the lap joint on a model airplane covering where an edge of a portion of the plastic layer lies on a surface of another portion of the plastic layer.
Referring now to the drawing, the reference character 10 indicates generally a model airplane embodying the principles of the invention. The model airplane 10 may be made to any suitable outer configuration and FIGURE l illustrates a model of a conventional airplane having a pair of wings 12 and a tail 14 iixedly attached to the main body section or fuselage 16 when operatively assembled together. A covering 18 extends over substantially the entire airplane frame and is generally attached to the main parts thereof prior to the assembling of the same.
The covering 18 comprises an outer layer or lilm of a clear plastic material 24 and an inner layer of adhesive 26 which is adhesively attached to the inside surface of the plastic layer 24 (FIGS. 4 and 5). The adhesive layer 26 may be of the pressure sensitive type. Hence, when storing the adhesive plastic prior to use as a covering 18, the adhesive 26 is preferably releasably attached to a sheet of release paper 30 (FIG. 3). A polyester resin such as Mylar has been found to be an acceptable plastic material. An acrylic material has been successfully used as a pressure sensitive adhesive.
Coloring for the covering 18 is provided in the adhesive layer 26. Dyes, such as inorganic pigments of the type used in paints, may be incorporated into the adhesive to provide the various colors. In this manner, the coloring of the model airplane is protected by the plastic outer layer 44 and, hence, does not wear away due to the exposure to the elements nor dissolve from the effects of fuel.
Alternatively, a dry adhesive layer 26 which is activated by heat or a solvent is also within the contemplation of this invention. This would include an initially sticky adhesive which may dry out due to exposure. By an application of a suitable material to the exposed face of a pressure sensitive adhesive, the same may also be converted `into a dry adhesive. To provide such a conversion, a powder made from a zinc stearate material was sprinkled over the exposed face of a pressure sensitive adhesive causing the same to loose its tackiness. After covering a portion of the model airplane frame and applying heat and pressure to the plastic layer 26, the adhesive was activated and caused a bond between the plastic and the frame. Zinc stearate is referred to merely for example, and other materials that would cause the cnverting of the pressure sensitive adhesive to a dry adhesive and the activation of the adhesive with heat, would also be suitable.
With the adhesive being initially dry rather than tacky, the adhesive coated plastic may be conveniently stored in rolls rather than sheets and any particular length thereof could be easily dispensed therefrom and shipped to the purchaser. Also, with a dry adhesive the adhesive coated plastic is manipulable into the proper position with greater facility, and furthermore there would be substantially less possibility of the plastic wrinkling when applying the same to the airplane frame.
The method or process for applying the covering to the frame will now he described in conjunction with the drawing. In applying the covering 18 to the frame of the model airplane, the length and shape constituting the covering or portions thereof, are initially cut out from a sheet comprising a layer of clear plastic material 24 and a layer of colored adhesive 26 coated to the plastic and releasably attached to a layer of release paper 30 (FIG. 3). Of course, if the adhesive were a dry adhesive, the layer of release paper would not be necessary. When the release paper 30 is removed from the cut out adhesive coated plastic, the same as shown in FIG. 4, may now be applied to a section 31 of the model airplane frame.
After applying,r the adhesive layer 26 to the frame, the plastic layer 24 is smoothened out in every direction to remove wrinkles therefrom and to press the adhesive layer 26 in tight contact with the area of the airplane it covers. Although the smoothing out of the plastic layer 24 straightens the same, it will be immediately apparent that the tautness is substantially less than desired.
To provide suicient tautness and to effect a secure bond between the frame of the model airplane 10 and the plastic layer 24, it is necessary to apply heat to the plastic layer 24 in order to cause the same to become more pliable. When the plastic layer cools it shrinks to the contours of the frame. Heat may be applied with an electric iron or a blower or other suitable heating devices. Preferably, heat should initially be applied to the outer perimeters of the frame to cause the plastic layer 24 thereat lto make a secure bond with the frame. Then, heat is applied to the area of the plastic layer 24 between the bonded perimeters and upon cooling the plastic shrinks tight against the frame. With particular reference to FIGURE 2, the initial application of heat .is applied along the lateral edges 32 of the wing 12 to bond the plastic thereto. When heat is applied to the surface of the plastic layer 24 between the edges 32, the same upon cooling shrinks over the ribs 34. The heating of the plastic also causes the adhesive to bond the plastic to the ribs 34. Moreover, the shrinking of the plastic causes a pressure against the frame that insures a secure bond.
However, the method of the invention does not require that the covering be initially placed on the frame in a careful and smooth manner or that the covering be wrinkle free. The heating of the plastic layer will remove all traces of wrinkles and provide a skin tight and wrinkle free covering.
For extremely porous frames, such as those made from balsa wood, the heat :is applied to the lateral edges for a suicient length of time to permit a portion of the adhesive layer 26 to impregnate the pores and thereby securely bond the plastic layer 24 to the frame edges, as is particularly shown in FIGURE 5. To insure that portions of the adhesive layer 26 irnpregnate into the top surface of the porous frame, it may be necessary to apply sufficient pressure with the heat in order to compress the adhesive and force the same into the pores. With the adhesive impregnated in the pores, a secure bond is made with the irregularly shaped walls of the pores.
Turning to FIGURE 8, the heating of the edge of the adhesive layer 26a causes the plastic layer 24a to make a secure bond with plastic layer 2412 at the lap joint or seam 36. The lap joint 36 on the covering 1S is the area where an edge of a portion of the plastic layer lies on the surface of another portion of the plastic layer. The part of the covering 18 at the joint 36 is compressed tight together with heat and pressure to afford a secure bond thereat. This prevents the seepage of the fuel used by the model airplane in between the plastic layer 24 and the frame. Moreover, the heat appears to seal or cure the adhesive and prevent the same from dissolving from the fuel. During the flying operation of the model airplane, a fuel :film often forms on the covering and heretofore would cause the dissolving or loosening of the covering from the trame.
With reference to FIGURES 6 and 7, the tail 14 includes a rudder 38, a iin 4t) and stabilizer 42. Stabilizer 42 includes a movable elevator 44. The movement of rudder 38 and elevator 44 may be controlled. As shown in FIGURE 7, the covering 13 is adaptable to provide a movable joint 50 to permit the rudder 3S to be pivoted outwardly away from iin 40. To accomplish this without additional parts, the covering 13 on the upper surface of the rudder 38 and iin 40 does not extend across the adjacent edges thereof. However, the covering 18 on the lower surfaces extends across the adjacent edges to afford a pivot 50 whereby rudder 38 may be pivoted away from lin 40 as shown in phantom in FIGURE 7. Note, that the adjacent edges of the iin and rudder are angled to permit the movement of the rudder upward or downward (FIG. 7). Similarly the aileron |56 on the wing 12 may use the covering 18 for a pivot joint.
From the foregoing description and drawing, it should be apparent that I have provided a novel covering for model airplanes and the method for applying the same. Although the covering was described in conjunction with model airplanes, the principles of the invention may also be applicable for the regular size airplane as well. The plastic adhesive coated material after being applied over the airplane frame is heated and upon cooling shrinks to the contour of the frame. The heat also causes the adhesive to bond the plastic to the frame. Hence, if a puncture occurs in the airplane covering the damage is thereby localized. Moreover, by heating the seam or lap over joint 36 of the covering 18, a secure bond is made with another portion of the covering 18, as illustrated in FIGURE 8. This prevents the seepage of fuel between the plastic layer and the frame. Furthermore, the covering herein is further adaptable to provide a pivoted joint for manipulating the airplane rudder or aileron and does not require attachment of additional parts that were previously required.
The adhesive layer 26 is dyed to a particular color and hence the application of the covering to the frame has eliminated the need to paint the airplane. Therefore, by predetermining the airplane color scheme, the various strips of adhesive plastic applied to the frame would correspond accordingly to the desired coloring. Moreover, any dirt and grime that collects on the plastic layer may be wiped clean therefrom and the airplane, even after much use, would have a new glossy appearance. Also, by having the coloring inside the adhesive and the plastic layer thereover, there is no damage or chipping of paint which, heretofore, invariably occurred after even the slightest use.
It is believed that my invention, its mode of construction and assembly, and many of its advantages should be readily understood from the forego-ing without further description and it should also be manifest that while a preferred embodiment of the invention has been shown and described for illustrative purposes, the structural details are nevertheless capable of wide variation within the purview of my invention as defined in the appended claims.
What I claim and desire to secure by Letters Patent of the United States is:
1. In combination with an airplane frame, a covering material applied thereto, said covering material comprising a flexible, clear heat-shrunk film of polyester resin precoated over substantially the entire surface of one side with a layer of adhesive containing coloring material interspersed therewith, said layer of adhesive and interspersed coloring material being bonded to said iilm.
2. The covering for airplane frames of claim 1, wherein said hlm is transparent whereby the color of said coloring material is visible through the lm but the material is insulated and protected from extraneous elements and materials by said film.
3. ln a method for covering an airplane frame with a covering material comprising a flexible, clear, heatshrinkahle film of polyester resin pre-coated on one side with a layer of adhesive containing coloring material, the steps of applying a predetermined length of said covering material to a section of said frame so that the film comprises the outer side thereof and thereafter applying heat to the film to cause the lm to shrink tautly to the contours of the frame and the adhesive to bond the lm to the frame.
d. The method of claim 3 wherein heat is applied to a lirst part of said lm at the perimeters of said frame to cause a first portion of the adhesive layer at the perimeters to bond said first part of the film with the frame, heat is applied to a second part of said lm between the bonded pcrimeters to cause the same to become more pliable and to cause a second portion of the adhesive layer to bond said second part of the film to the frame, and cooling said second part of the film to cause the same to shrink tautly tothe contours ofthe frame.
5. A covering for a model airplane frame comprising: an outer plastic lm; an adhesive layer of material between said plastic film and said frame, said adhesive layer securing said plastic film to the frame; and said frame including at least one movable section, the edge of the movable section being adjacent an edge of another section of the frame, each of said sections having at least two surfaces, the covering on one surface of said sections extending only to the adjacent edges of the sections, the covering on the other surface of said sections extending across said edges to afford a pivot joint means whereby said movable section may be pivoted with respect to the other sectio-n.
References Cited UNITED STATES PATENTS 2,096,750 10/1937 Lawrence 41-34 2,560,742 7/1951 Redor 46-'76 2,767,436 10/1956 Noland 46-76 2,802,764 8/1957 Slayter et al. 181-33 2,920,682 1/1960 Lindberg 46-76 3,273,281 9/1966 Harrison 46-76 OTHER REFERENCES American Modeler, Sketchbook, May 1959, vol. 52, p. 37.
American Modeler, Sketchbook, March 1958, p. 10.
ANTON O. OECHSLE, Primary Examiner.
RCHARD C. PINKHAM, F. BARRY SHAY, Examiners. T. ZACK, Assistant Examiner.