US2814907A - Toy aircraft - Google Patents

Description

Dec. 3, 1957 w. B. SEARS 2,814,907

TOY AIRCRAFT I Filed April 2'7, 1956 4 Sheets-Sheet 1 IN V EN TOR.

WILLIAM B. SEARS ATTORNEYS Dec. 3, 1957 w. B. SEARS 2,814,907

TOY AIRCRAFT Filed April 2'7, 1956 4 Sheets-Sheet 2 INVENTOR.

WILLIAM B. SEARS AT TOR NEYS W. B. SEARS Dec. 3, 1957 TOY AIRCRAFT 4 Sheets-Sheet 3 Filed April 27, 1956 v INVENTOR. WlLLiAM B. SEARS ATTORNEYS w. B. SEARS 2,814,907

. TOY AIRCRAFT Dec. 3, 1957 4 Sheqets-Sheet 4 Filed April 27. 1956 lNVENTbR.

I WILLIAM B. SEARS BY B 9 ATTORNEYS TOY AIRCRAFT William B. Sears, Denver, Colo.

Application April 27, 1956, Serial No. 581,104

7 Claims. (Cl. 46-78) The present invention relates to toy flying machines, both of the orthopter and propeller-driven types, and is a continuation-in-part of my copending application, Ser. No. 354,263, filed May 11, 1953, now abandoned.

My invention aims to provide a multipiece main body frame for either of the afore-mentioned types of toy aircraft which receives a respective drive shaft during assembly in such a manner that the shaft is journal supported at spaced points along its length in circumferentially enclosed journals when assembly is complete.

As a further object the invention aims to provide a wing structure of durable and simple construction which can be used on a propeller-driven toy aircraft, and, when used on an orthopter, will forwardly propel the orthopter during both the up and down strokes of the flapping of the wings.

With yet additional objects and advantages in view which, with the foregoing, will appear and be understood in the course of the following description and claims, the invention consists in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

Figure 1 is a perspective view of the orthopter embodiment of my invention with the wings shown at the start of their downward stroke.

an enlarged scale of the three parts comprising the main frame.

Fig. 3 is a perspective view of the orthopter embodiment with part of the left wing broken away and with the wings shown at the start of their upward stroke.

Fig. 2 is an exploded fragmentary perspective view to Fig. 4 is an enlarged perspective view of the drive shaft 3 of the orthopter embodiment.

Fig. 5 is a perspective view of the airplane embodiment. Fig. 6 is an enlarged perspective detail view partly in section illustrating the attachment of the tail to the main frame.

'Fig. 7 is an enlarged perspective detail view illustrating the connection of the left wing spar of the airplane embodiment to the main frame.

Fig. 8 is a perspective View of a modified orthopter embodiment of my invention; and

Fig. 9 is a side elevational-view of the modified orthopter embodiment.

Referring to the drawings, and particularly Fig. 2, it is seen that the main frame of my aircraft has three interfitting parts 1012 which may be bonded together by any suitable bonding agent. Part 10 has two vertically spaced longitudinals 13, 14 which are joined at their rear ends by a rib 15. From this rib the longitudinals 13, 14 diverge slightly as they extend forwardly to a rib 16 which becomes an intermediate rib when the body is assembled. Upper longitudinal 13 terminates at rib 16 whereas the lower longitudinal 14 continues forwardly to an upstanding post 17 which constitutes a major part of a forward rib upon assembly. A generally U-shaped gripping piece 18 depends from the lower longitudinal and makes con- 2,814,907 Patented Dec. 3, 1957 nections therewith at the base of post 17 and somewhat aft of rib 16. The latter has a widened section 20 at its upper end which extends rearwardly with respect to the rib proper and presents a forwardly directed step 21. A laterally centered slot 22 extends vertically completely through the section 20 and part way down into the rib proper to a point about midway between longitudinals 13, 14. From the front the slot 22 is open for its full vertical length whereas at the rear it is open only below the section 20. Post 17 is bifurcated at its upper end by a vertical slot 23 which extends to such a depth that the bases of the slots 22, 23 are alined with the crook of a rearwardly faced hook 24. This hook projects upwardly near the rear rib 15 such that the crook is substantially midway between longitudinals 13, 14.

Frame part 11, as viewed from the top, is generally T-shaped by way of a rearwardly extending leg 25 and a pair of oppositely extending arms 26 at the forward end thereof. Depending from the junction of the leg 25 and arms 26 is a rib component 27 for surmounting the post 17 to complete a forward rib. This rib component is necked to provide a tongue 28 for fitting into the slot 23. At its rear end the leg 25 has a tongue 30 of a generally inverted L-shape for fitting into slot 22 in such a manner that the rear end of the leg proper seats on the step 21. Positioning flanges 31, 32 are located rearwardly and forwardly, respectively, of the tongues 28, 30 and extend laterally beyond both sides thereof to engage the rear face of post 17 and the front face of rib 16.

The tips of tongues 28, 30 are spaced slightly from the floors of the slots 22, 23 to provide journals for a drive shaft, numbered 33 in the case of the orthopter and 34 for the propeller driven embodiment. In both instances the drive shaft is terminated at its rear end by a hook 35 for receiving the forward end of an elastic motor 36. This motor may be one or more rubber bands and it is held near the rear end of the frame by the hook 24.

Arms 26 of part 11 have shot posts 37 at their outer ends and have transverse slots 38 at the base of these posts for receiving wing spars. Part 12 fits over part 11 between the posts 37 and serves to cover slots 38. Positioning of part 12 is aided by dowels 40 which seat in dowel openings 41 in the arms 26.

In the orthopter embodiment the shaft 33 is formed with a pair of oppositely disposed cranks 42, 43 located between the ribs 16, 17 and has a winding crank at its forward end. These cranks thread through one end of pitmans 44, 45 which have their other ends connected to drive arms 46, 47 provided at the inner ends of respective wing spars 48, 49. Each of these spars has an intermediate hinge section 50 bent at approximately right angles to the respective spar and drive arm. These hinge sections are journaled in the slots 38 of arms 26 so that a turning of crank shaft 33 causes an up and down flapping of the wing spars. A thrust bearing is sleeved on the crank shaft between intermediate rib 16 and the rear crank and may take the form of one or more washers 51 and a ball or cylinder 52.

It will be noted that the wing spars 48, 49 gradually curve rearwardly. The wings are completed by a single piece of light sheeting 53 of a suitable material such as thin plastic, silk, tissue, etc. Along its forward edge this wing sheeting is rolled over and cemented to the spars, and the sheeting is also cemented along its center line to the top of the upper longitudinal 13. At the nose of the body frame the sheeting 53 has a relief cutout 54. The trailing-edge of the wing sheeting is purposely curved rearwardly from the tips of the wing spars to its rearmost point of contact 55 with the longitudinal 13, and this point 55 is intentionally substantially rearward of the spars. Of extreme importance is the fact that the wing sheeting is purposely made slack between the tips of the wing spars and the'main body of the orthopter. Accordingly, a line drawn directly from the tip of one of the spars to the point 55 along the surface of the wing sheeting is not straight and is located forwardly of the trailing edge of the respective wing.

The purpose of the slack in the wing'sheeting and the surplusage of sheeting rearwardly of the wing spars is illustrated in Figs. 1 and 3. In the latter the wings are shown at their lowest limit of'travel and just as'they start upwardly'the resulting downward "pressure in the wings causes the wing sheeting to cup downwardly. This downward cupping remains until the wings reach their upper limit oftravel (Fig. l) and start their down-flap at which time the wing sheeting is cupped upwardly and continues thus during the downward travel. The result of this reversing cupping action of the wings is to change the effective angle of attack of the wings during the up-flaps and down-flaps so that the wings substantially continuously propel the orthopter forwardly.

Piano wire is very satisfactory for the working parts and gives a flexibility to the wing spars 48, 49 which tends to increase the cupping of the wings, especially when a wind is encountered. It also reduces breakage from impact of the orthopter withoth'er objects to a minimum.

Flight control of the orthopter is aided by a flat tail 57 having a wire border frame covered with thesame sheeting material as for the wings. The free end portions 58 (Fig. 6) of the border frame wire are secured at the rear of the body as by cement and a thread winding '60. With this arrangement the tail 57 can be selectively tilted with respect to the orthopter body by manually binding the wire portions 58 just rearwardly of the thread 60. A slight upward slope of the tail gives good flight characteristics in that it tends to cause a lifting of the nose ofthe orthopter during flight.

The propeller driven embodiment, hereinafter termed the airplane to distinguish from the orthopter, uses the same body frame and tail as the orthopter, and its wings are of the same general construction in that the spars and wing sheeting of the orthopter and airplane are of the same-shape. However, the airplanes wing spars, denoted 6l, 62, are held stationary with respect to the frame and hence-do not have drive arms at their inner ends. In place of these drive arms the Wing spars have turnedback terminal locking sections 63. The latter'bearagainst the underside of the frame arms 26 beneath respective intermediate sections 64 which fit into the slots 38 in the same manner as the hinge sections 50 of the orthopters wing spars. Desirably, the airplane wing spars are given a slight upward tilt. The airplane is provided with a vertical rudder 65 which has a wire border frame covered with thin sheeting in the same manner as the tail 7. This rudder has the free ends of its border frame secured to the upper longitudinal 13 forwardly of the tail connection in the same way as the latter and namely by glue and thread 67. The drive shaft 3d of the airplane has a propeller 68 secured to its forward end. Sleeved in the shaft between this propeller and the forward rib 17 is a thrust bearing comprising one or more washers 7 0 and a ball or cylinder 71.

In assembling the main body frame. Whether it be for the orthopter or airplane, the hook 55 at the rear end of the respective drive shaft 33 or 34 is inserted endwise through the slot 22 in the intermediate rib 16 to seat the shaft at the bottom of slots 22, 23 before the frame part 11 is interfitted by its tongues 28, 30 with these slots. Similarly the hinge sections 50 of the orthopter spars or the intermediate 64 of the airplane spars are inserted in the slots 38 of arms 26 before frame part 12 is fitted over the arms.

A modified orthopter is illustrated in Figures 8-9 and it will be noted that it differs from the orthopter hereinbefore described in that a single piece of sheeting 1-53 is used for both the wings and the tail. Also, instead of having a wire border frame, the tail is supported by a single central length of wire 158 which extends rearwardly from the main frame, the forward root end of the wire being secured to the frame in any suitable manner. The Wire 158 is bent to give a slight upward slope for flight stability. At its forward end the sheeting 153 is secured to Wing spars 149 which may be straight as shown or curved as are the spars 49. Along its longitudinal center line the sheeting gradually reduces in width and is purposely made slack so that the major portion of the sheeting will cup upwardly and downwardly during flapping of the wing spars.

The advantages of the invention will, it is thought, have been clearly understood from the foregoing detailed description of the embodiment which I have elected to illustrate. Minor changes in the details of construction will suggest themselves and may be resorted to without departing from the spirit of the invention, wherefor it is my intention that no limitations be implied and that the hereto annexed claims be given a scope fully commensurate with the broadest interpretation to which the employed language admits.

What I claim is:

1. In a toy aircraft, a drive shaft, a first frame part providing a longitudinal member having a pair of longitudinally spaced ribs near its forward end, said ribs each having a slot therethrough open front and back for insertion of the drive shaft before assembly of the frame, a second frame part-extending between said ribs and having tongues projecting into said slots with the tips of the tongues spaced from the floors of the slots to provide a pair of circumferentially enclosed journals for the drive shaft, a rearwardly facing hook near the rear end of the first frame part, said shaft presenting a forwardly facing hook at its rear end, and an elastic motor extending between said hooks.

2. In a toy aircraft, a drive shaft, a first frame part providing vertically spaced longitudinal members of dif ferent lengths joined at the front of the shorter said member by a rib and joined at the rear, the longer of said longitudinal members extending forwardly beyond said rib and providing another rib located in forward spaced relation from the first-mentioned rib, said ribs each having a slot therethrough open front and back for insertion of the drive shaft before assembly of the frame, a second frame part extending between said ribs and having tongues projecting into said slots with the tips of the tongues spaced from the floors of the slots to provide a pair of circumferentially enclosed journals for the drive shaft, a rearwardly facing hook near the rear end of the first frame part, said shaft presenting a forwardly facing hook at its rear end, and an elastic ,motor extending between said hooks.

3. In a toy aircraft, a drive shaft, a first frame part providing vertically spaced longitudinal members of different lengths joined at the front of the shorter said member by a rib and joined at the rear, the longer of said longitudinal members extending forwardly beyond said rib and providing another rib located in forward spaced relation from the first-mentioned rib, the latter having a step adjoining the shorter longitudinal member, said ribs each having a slot therethrough open front and back with the slot of the first-mentioned rib extending through said step, the slots permitting insertion of the drive shaft before assembly of the frame, a second frame part seated in said step and on the free end of the second-mentioned rib and having tongues projecting into said slots with the tips of the tongues spaced from the floors of the slots to provide a pair of circumferentially enclosed journals for the drive shaft, a rearwardly facing hook near the rear end of the first frame part, said shaft presenting a forwardly facing hook at its rear end, and an elastic motor extending between said hooks.

4. In a toy aircraft, a drive shaft, a first frame part providing a longitudinal member having a pair of longitudinally spaced ribs near its forward end, said ribs each having a slot therethrough open front and back for insertion of the drive shaft before assembly of the frame, a second frame part extending between said ribs and having tongues projecting into said slots with the tips of the tongues spaced from the floors of the slots toprovide a pair of circumferentially enclosed journals for the drive shaft, said second frame part providing a laterally centered transverse member at its forward end, a pair of wing spars connected to the ends of said transverse member, a piece of thin flexible Wing sheeting connected at its forward end to said spars and held against the top of said first frame part, an elastic motor mounted rearwardly of said ribs and operatively connected to the rear end of said drive shaft, and a tail extending rearwardly from said first frame part.

5. The structure of claim 4 in which said wing spars make rigid connections with said transverse member and in which a propeller is operatively connected to the forward end of said drive shaft.

6. The structure of claim 4 in which said shaft is formed with a pair of oppositely disposed cranks located between said ribs; and said Wing spars are hingedly connected to said transverse member and operatively connected to said cranks for imparting vertical flapping movement to said spars in response to a turning of the drive shaft.

7. In an orthopter, a rigid body including upper and lower vertically spaced longitudinal frame members joined at the front by a pair of longitudinally spaced vertical ribs and joined at the rear, said body having a transverse member at the top and front which is laterally centered with respect to the body, an elastic motor mounted between said longitudinal frame members and rearwardly of said ribs, a crank shaft extending through said pair of ribs and operatively connected at its rear end to said elastic motor and at its front end presenting a winding crank, said shaft having a pair of oppositely disposed drive cranks between said ribs, a thrust bearing sleeved on the shaft between said drive cranks and the rearmost of said pair of ribs, a pair of oppositely directed flexible wing spars extending laterally from the body and hingedly connected to the ends of said transverse member, means operatively interconnecting said spars and said drive cranks for imparting vertical flapping movements to the spars in response to a turning of said drive shaft, and a piece of thin flexible sheeting connected at its forward end to said spars and held against the top of said upper longitudinal frame member, said sheeting being slack and sloping rearwardly from the tips of said spars to the rear extreme of the securement of said sheeting to said upper longitudinal frame member, and a generally flat tail extending rearwardly from the body and so attached thereto as to permit said tail to be yieldingly positioned at selected angularities inclined from the horizontal.

References Cited in the file of this patent UNITED STATES PATENTS 1,758,178 Slinn May 13, 1930 2,321,977 Boatright June 15, 1943 FOREIGN PATENTS 17,154 Great Britain 1910

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