US3594946A

US3594946A - Plastic model construction

Info

Publication number: US3594946A
Application number: US797102A
Authority: US
Inventors: Leslie De Witt Jr
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-02-06
Filing date: 1969-02-06
Publication date: 1971-07-27
Anticipated expiration: 1988-07-27

Abstract

A molded plastic model, such as a model airplane, having a molded plastic body consisting of mating body shells which are mutually joined along adhesively bonded seams, and thin molded plastic skin sections which are applied over and secured to the sides of the body in such a way as to obscure the seams and reinforce the body. An improved molded plastic wing construction is provided for the model airplane.

Description

United States Patent [72] Inventor Leslie Dewitt, Jr.

2434 N. Durlee, El Monte, Calif. 9173 [21 Appl. No. 797,102 [22] Filed Feb. 6, 1969 [45] Patented July 27, 1971 [54] PLASTIC MODEL CONSTRUCTION 16 Claims, 8 Drawing Figs.

[52] US. Cl. 46/76 R ...A63h 27/00 [50] Field of Search. 46174, 76, Y 79, 82,162,244/117, 119, 126

[56] References Cited UNlT ED STATES PATENTS f 1,572,166 2/ 1926 Smith 46/76 1,581,980 4/1926 Pearson 46/76 10/1936 'Selley 46/76 UX 2,186,051 1/1940 Walker.. 46/76 X 2,195,695 4/1940 Daniel 46/76 3,395,484 8/ 1968 Smith 46/162 3,438,481 4/1969 Durand 206/4533 Primary Examiner-Louis G. Mancene Assistant ExaminerD. L. Weinhold AttarneyBoniard 1. Brown PATENTEU JUL27 19?: 3, 594846 sum 1 0r 2 //v I/EA/TOR LESL/E 05 1 1/07; JR.

PATENTED JUL27 I97! SHEET 2 OF 2 NT) W n W M Z PLASTIC MODEL CONSTRUCTION BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates generally to models and more particularly to improvements in molded plastic models.

As will appear from the ensuing description, at least some features of the invention may be utilized to advantage in various types of plastic models. However, the invention is concerned primarily with plastic model airplanes which are capable of flight. For this reason, the invention will be disclosed in connection with models of this class.

2. Prior Art A wide variety of plastic model airplanes have been devised. Such airplanes, however, are most frequently scale models which are not designed to fly. This inability of such plastic models to fly constitutes a distinct disadvantage of the prior art in this field and is due, in part, to the weight of the model, and, input, to their poor aerodynamic characteristics.

Another disadvantage of the existing plastic airplane models resides in the fact that such models are made in many separate pieces which must be assembled and adhesively joined. The plastic cement which is used for this purpose is actually a solvent which softens or liquifles the surfaces to be bonded so as to effect fusion of these surfaces when they are placed in contact. Because of this dissolving action of the cement, it is very difficult to join plastic parts without excessive erosion' or melting of the parts. This problem of dissolution of the plastic becomes more acute the thinner the plastic. Accordingly, sheet plastic model airplanes are generally provided with a substantial wall thickness which is much too heavy to permit flight. Moreover, cementing plastic parts, such as plastic body shells, to one another with neat seams between the parts is most difficult to accomplish, particularly for younger children. If the seams are not neatly cemented, of course, the finished model will have a very unprofessional appearance.

SUMMARY OF THE INVENTION The present invention provides an improved sheet plastic model which avoids the above-noted and other disadvantages of the existing models of this class and, in addition, possesses various other beneficial features of construction. As noted earlier, the invention is applicable to a wide variety of plastic models but is concerned primarily with and will be disclosed in connection with a model airplane.

In this regard, one aspect of the invention is concerned with providing a sheet plastic model airplane which is capable of flight when powered with a rubberband motor or the like. According to this aspect, the invention provides a model airplane having a thin-walled molded plastic fuselage body consisting of mating shells which may be assembled and cemented at the factory. Applied over and secured to the sides of this body are thin lightweight molded plastic skin sections. These skin sections serve the multiple function of covering the body seams, providing the body with a finished professional appearance, and reinforcing the body. According to a feature of the invention, the body shells may be provided with abutting seam flanges and/or indentations which cooperate with the skin sections to reinforce the fuselage. This results in a molded plastic fuselage which is relatively light in weight and yet sufficiently rigid for flight. According to another feature of the invention, the skin sections may be arranged to cushion impact of the fuselage with the ground or other object.

Another aspect of the invention is concerned with an improved molded plastic wing construction for the model airplane. According to this aspect, the wing is composed of upper and lower moldedplastic panels having parametrical regions of abutting contact at which the panels are easily joined. One of these wing panels, preferably the lower panel, defines a channel-shaped wing spar formation which is cemented to the opposite panel to reinforce the wing. The open side of this spar formation may be closed by a plastic strip to enhance the appearance of and further reinforce the wing. Theinvention also provides novel registry meansfor accurately locating the wing relative to the fuselageto permit attachment of the wing to the fuselage and the optimum position and attitude for flight.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a model airplane according to the invention with a portion of the fuselage broken away for clarity;

FIG. 2 is a fragmentary bottom view of the airplane model;

FIG. 3 is an enlarged section taken on line 3-3 in FIG. 1;

FIG. 4 is an enlarged section taken along line 4-4 in FIG. 3;

FIG. 5 is a fragmentary exploded view of a portion of the fuselage and wing of the airplane model;

FIG. 6 is an enlarged section taken on line 66 of FIG. 2; FIG. 7 is an enlarged section taken on line 7-7 of FIG. 2;

and

FIG. 8 illustrates a modification of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to these drawings, there is illustrated an airplane model 10 according to the invention including a fuselage 12, a wing 14, and a tail assembly 16. The airplane has a landing gear 18 and a propeller 20 powered by a rubberband 22. One important aspect of the invention is concerned with the construction of the fuselage 12. According to this aspect, the fuselage is composed of an inner thin-walled molded plastic body 24 and an outer lightweight molded plastic skin 26. The skin is cemented to the body in such a way as to reinforce the body and provide the fuselage with a professional appearance. In this latter regard, an important function ofthe skin 26 is to cover and obscure cemented seams and other undesirable surface features of the fuselage body, as hereinafterexplained.

Referring to the fuselage 12 in greater detail, the inner fuselage body 24 is constructed in two

mating sections

28, 30 which comprise thin-walled molded plastic shells. These shells have outwardly directed flanges 32 extending longitudinally along the top and bottom sides of the shells in their parting plane.

Shells

28, 30 are joined to provide the fuselage body 24 by cementing the flanges 32 to one another. In the event that the present model is to be sold in kit form, the

fuselage shells

28, 30 are-preferably assembled and joined at the factory to permit precise alignment of the shells and proper cementing of their abutting flanges 32. Formed in the sides of the shells are reinforcing indentations 34. These indentations may also provide access openings to the interior of the fuselage body 24 to facilitate installation of the landing gear 18 and the rubberband motor 22.

The fuselage skin 26 comprises separate molded

plastic seetions

36, 38, 40, and 42 which are applied over and cemented to the top, bottom, and sides, respectively, of the fuselage body 24 in the manner illustrated. In this regard, it will be observed that the skin sections are shaped to match their respective body sides, such that the adjacent skin sections have abutting edges located along the longitudinal edges of the body. In FIGS. 1 through 4, the upper and lower

fuselage skin sections

36, 38 engage and are cemented along the longitudinal centerlines to the outer edges of the body flanges 32 and along their outer longitudinal edges to the upper and lower body walls. The

side skin sections

40, 42 are cemented to the sidewalls of the fuselage body about the sidewall indentations 34 and along the longitudinal edges of the fuselage body.

It is now evident, therefore, that the fuselage skin 26 serves the dual function of covering the cemented seams, i.e., flanges 32, and other undesirable surface features, i.e., indentations 34, of the fuselage body 24 and reinforcing the body. The fuselage 12 may thus be constructed of relatively light gauge plastic and yet possess sufficiently high strength and rigidity the

body shells

28, 30 and their abutting flanges 32 provide relatively rigid tubular configurations or sectionsextending lengthwise of the fuselage. The sidewalls of the fuselage are similarly reinforced by the sidewall indentations of the body shells and the side skin sections. The several

fuselage skin sections

36, 38, 40, 42 may be embossed to simulate rivets, win-.

dow edging, and other desirable features of the full-scale aircraft.

HO. 8 illustrates a modification of the invention wherein the upper fuselage skin section 36 (as well as the lower fuselage skin section 38 not shown) are spaced from the cemented inner body flanges 32. ln this case, the skin sections provide a cushioning action in the event of impact of the fuselage with the ground or other object. Another aspect of the invention is concerned with the construction of the wing l4. Referring to FIGS. through 7, it will be seen that the wing is constructed in two

sections

14L, 14R which are essentially mirror or images of one another. Each wing section has upper and lower molded plastic panels 44 and 46which are cemented to one another along the edges of the wing sections. The lower wing panel 44 has an upwardly projecting channel-shaped spar formation 48 which seats against and is cemented to the upper wing panel 46. The lower open side of the spar formation is closed by a plastic strip insert 50 which is cemented in place. The

wing sections

14R, 14L thus possess relatively high lateral bending resistance or strength.

As shown in FIG. 5, the lower wing panels 44 extend inwardly beyond the inner edges of the upper wing panels 46 and overlap one another. These overlapping ends of the wing panels have transverse interfitting channel formations 52 which receive the fuselage body flanges 32. The overlapping ends of the lower wing panels have additional longitudinal channel formations 54 which receive projecting rib or lug formations 56 on the fuselage body 12. These interfitting flanges, channel formations, and lugs locate the

wing sections

14R, 14L relative to one another and to the fuselage. The wing sections are secured to one another and to the fuselage by cementing the contacting surfaces of these parts. Wing 14 is completed by an upper center panel 58 which is shaped to bridge the gap between and merge smoothly with the upper wing panels 46. This center wing panel has channel formations 60 along its leading and trailing edges to receive the fuselage body flanges 32. The center panel is secured in position by cementing the contacting surfaces of the panel and the underlying overlapping ends of the upper wing panels 46.

The tail assembly 16 of the airplane includes a rudder 62 and a stabilizer 64. Rudder 62 is formed in two mating molded plastic shells which are cemented to one another about contacting edges. The underside of the rudder has an opening for receiving upstanding lugs 66 integrally molded on the rear ends of the

fuselage body shells

28, 30. These lugs serve to locate the rudder relative to the fuselage. The rudder is cemented in place. Stabilizer 64 is composed of two molded plastic panels of sections 68, 70 (FIG. 7) which are cemented to one another along their contacting surfaces. The upper stabilizing panel 68 has aft planar portions 72 which project rearwardly of the lower stabilizer panel 70 to form simulated control surfaces.

The propeller 20 of the airplane has a central shaft 74 which is journaled in a bearing 76 mounted within the nose of the fuselage 12. The rear end of the propeller shaft is bent to form a hook 78 for connection to the front end of the rubberband 22. The rear end of the rubberband is fixed to a cross-shaft 80 which extends across the interior of the fuselage body 24, adjacent its aft end and through holes in the body sidewalls. Preferably, the underside of the fuselage is provided with openings, as illustrated, through which access may be had to the interior of the fuselage for replacing the rubberband, when necessary. As already noted, initial installation of the rubberband may be accomplished through the sidewall openings in the fuselage body 24 prior to cementing of the

fuselage skin sections

40, 42 to the body sidewalls.

' The airplane landing gear 18 is conventional and includes a pair of wheels 82 which are rotatably mounted on the ends of the U-shaped spring wire carriage 84. The central connecting portion 86 of this wire wheel carriage extends through and is secured to the front end of the fuselage 12 in any convenient way. A tail skid 88 may be provided at the rear end of the fuselage.

While the invention has been disclosed in connection with a specific physical embodiment thereof, it is evident that various modifications of the invention are possible within the spirit and scope of the following claims.

I claim:

l. A model airplane comprising:

a fuselage including a pair of mating molded plastic shells joined to one another along adhesively bonded seams, and

a relatively thin preformed molded plastic skin including separate preformed molded plastic skin sections applied over and adhesively secured to the sides, respectively, of said fuselage, whereby certain of said skin sections cover said seams.

2. A model according to claim 1 wherein:

said seams comprise abutting flanges on said shells which are adhesively bonded to one another.

3. A model according to claim 1 wherein:

portions of said skin sections are spaced from the outer surface of said fuselage to cushion impact of said fuselage with another object.

4. A model according to claim 2 wherein:

said spaced skin portions overlie said flanges and said flanges extend outwardly from said fuselage to said spaced skin portions, and

the-outer edges of said flanges are adhesively bonded to the overlying spaced skin portions to provide said fuselage with relatively rigid tubular sections.

5. A model according to claim 2 wherein:

said flanges extend along said top and bottom sides of said fuselage,

the lateral sides of said fuselage have reinforcing indentations, and

the lateral sections of said skin covering said lateral fuselage sides are adhesively bonded to the latter sides about said indentations to provide said latter sides with substantial rigidity.

6. A wing for a model airplane of the character described comprising:

upper and lower separately preformed molded plastic wing panels having abutting edge regions adhesively bonded another to form a hollow airfoil section, and

one of said wing panels being indented from the outside longitudinally of said wing to define within said airfoil section of channel-shaped spar formation abutting and adhesively bonded to the other wing panel.

7. A wing according to claim 6 wherein:

said spar formation defines a channel in the outer side of said one wing panel, and

an insert secured within said channel to conceal the latter.

8. A model comprising:

a hollow thin-walled molded plastic inner body including mating preformed molded plastic shells adhesively joined along connecting seams,

thin-walled preformed molded plastic skin sections applied to the exterior of and adhesively bonded to said body so as to cover said body seams; and

at least one skin section having a central portion spaced from the exterior body surface and edge portions contacting and adhesively bonded to said body at opposite sides of said central portion to define within said body a hollow reinforcing tubular section.

9. A model according to claim 8 wherein:

said body shells have abutting outwardly directed adhesively bonded flanges forming said seams and extending from to one said body surface to said central portion of said one skin section; and v the outer edges of said flanges are adhesively bonded to said central skin portion to form a reinforcing rib between said 7 central skin portion and body.

10. A model according to claim 8 wherein:

said central portion of said one skin section is devoid ofsupport from said body between said edge portions of said latter skin section, whereby said central skin portion is yieldable to cushion an impact.

1!. A model according to claim 8 wherein:

said body has at least one inducted recess covered by one skin section, and

said latter skin section is adhesively bonded to said body about said recess to form with the latter a reinforcing tubular section.

12. A model airplane comprising:

a hollow thin-walled molded plastic fuselage having upper and lower walls and including mating preformed molded plastic shells with outwardly directed adhesively bonded flanges along the longitudinal centerlines of said walls,

a hollow molded plastic wing extending across one of said fuselage walls having a transverse channel receiving the adjacent fuselage flanges to locate said wing relative to said fuselage in the longitudinal direction of said wing and the lateral direction of said fuselage, and

said wing and one fuselage wall having additional mating formations for locating said wing relative to fuselage in the lateral direction of said wing and the longitudinal direction of said fuselage.

13. A model airplane according to claim 12 wherein:

said mating formations comprise at least one raised rib on said one fuselage wall extending normal to the fuselage flanges and a longitudinal channel in said wing receiving said rib.

M. A model airplane according to claim 13 wherein:

said. wing comprises separate right and left wing sections having overlapping thin-walled panels said panel of one wing section seats at one side against said one fuselage wall and said wing panel channels are indented into said latter panel side and form corresponding raised formations on the opposite side of said latter wing panel, and

said panel of the other wing section has channels receiving said latter raised formations.

15. A model airplane according to claim 14 wherein:

said wing includes a separate cover panel overlying said overlapping wing panels.

16. A model airplane according to claim 12 including:

a relatively thin preformed molded plastic skin including separate preformed molded plastic skin sections applied to the exterior of and adhesively bonded to said fuselage to cover said flanges.

Claims

1. A model airplane comprising: a fuselage including a pair of mating molded plastic shells joined to one another along adhesively bonded seams, and a relatively thin preformed molded plastic skin including separate preformed molded plastic skin sections applied over and adhesively secured to the sides, respectively, of said fuselage, whereby certain of said skin sections cover said seams.

2. A model according to claim 1 wherein: said seams comprise abutting flanges on said shells which are adhesively bonded to one another.

3. A model according to claim 1 wherein: portions of said skin sections are spaced from the outer surface of said fuselage to cushion impact of said fuselage with another object.

4. A model according to claim 2 wherein: said spaced skin portions overlie said flanges and said flanges extend outwardly from said fuselage to said spaced skin portions, and the outer edges of said flanges are adhesively bonded to the overlying spaced skin portions to provide said fuselage with relatively rigid tubular sections.

5. A model according to claim 2 wherein: said flanges extend along said top and bottom sides of said fuselage, the lateral sides of said fuselage have reinforcing indentations, and the lateral sections of said skin covering said lateral fuselage sides are adhesively bonded to the latter sides about said indentations to provide said latter sides with substantial rigidity.

6. A wing for a model airplane of the character described comprising: upper and lower separately preformed molded plastic wing panels having abutting edge regions adhesively bonded to one another to form a hollow airfoil section, and one of said wing panels being indented from the outside longitudinally of said wing to define within said airfoil section of channel-shaped spar formation abutting and adhesively bonded to the other wing panel.

7. A wing according to claim 6 wherein: said spar formation defines a channel In the outer side of said one wing panel, and an insert secured within said channel to conceal the latter.

8. A model comprising: a hollow thin-walled molded plastic inner body including mating preformed molded plastic shells adhesively joined along connecting seams, thin-walled preformed molded plastic skin sections applied to the exterior of and adhesively bonded to said body so as to cover said body seams; and at least one skin section having a central portion spaced from the exterior body surface and edge portions contacting and adhesively bonded to said body at opposite sides of said central portion to define within said body a hollow reinforcing tubular section.

9. A model according to claim 8 wherein: said body shells have abutting outwardly directed adhesively bonded flanges forming said seams and extending from said body surface to said central portion of said one skin section, and the outer edges of said flanges are adhesively bonded to said central skin portion to form a reinforcing rib between said central skin portion and body.

10. A model according to claim 8 wherein: said central portion of said one skin section is devoid of support from said body between said edge portions of said latter skin section, whereby said central skin portion is yieldable to cushion an impact.

11. A model according to claim 8 wherein: said body has at least one inducted recess covered by one skin section, and said latter skin section is adhesively bonded to said body about said recess to form with the latter a reinforcing tubular section.

12. A model airplane comprising: a hollow thin-walled molded plastic fuselage having upper and lower walls and including mating preformed molded plastic shells with outwardly directed adhesively bonded flanges along the longitudinal centerlines of said walls, a hollow molded plastic wing extending across one of said fuselage walls having a transverse channel receiving the adjacent fuselage flanges to locate said wing relative to said fuselage in the longitudinal direction of said wing and the lateral direction of said fuselage, and said wing and one fuselage wall having additional mating formations for locating said wing relative to fuselage in the lateral direction of said wing and the longitudinal direction of said fuselage.

13. A model airplane according to claim 12 wherein: said mating formations comprise at least one raised rib on said one fuselage wall extending normal to the fuselage flanges and a longitudinal channel in said wing receiving said rib.

14. A model airplane according to claim 13 wherein: said wing comprises separate right and left wing sections having overlapping thin-walled panels, said panel of one wing section seats at one side against said one fuselage wall and said wing panel channels are indented into said latter panel side and form corresponding raised formations on the opposite side of said latter wing panel, and said panel of the other wing section has channels receiving said latter raised formations.

15. A model airplane according to claim 14 wherein: said wing includes a separate cover panel overlying said overlapping wing panels.

16. A model airplane according to claim 12 including: a relatively thin preformed molded plastic skin including separate preformed molded plastic skin sections applied to the exterior of and adhesively bonded to said fuselage to cover said flanges.