1. Field of the Invention
The invention generally relates to a horizontal flight control device of a catapult toy glider, more particularly, the invention relates to a lightweight design be installed on existing toy glider to make horizontal tail can move further to allow the toy glider to climb as high as possible and then glide down gently.
2. Description of the Related Art
Fly to high altitude and glide down slowly is people's desire about a glider. Because catapult launch with very fast initial speed, launch toward the sky are the benefits attached to the catapult launch for onlookers and bystanders. In order to make the glider fly high, some use folding wings to reduce launch resistance, some use movable horizontal tail to control the flight locus, both approaches obtained the goal of vertical rise fly.
The existing inventions use folding wings mechanism such as disclosed in the following patents: U.S. Pat. No. 2,078,374A (John Drobniewsky), Arrow glider. U.S. Pat. No. 2,128,747A (Johnson Tool & Engineering Inc), Toy glider. U.S. Pat. No. 2,268,487A (Jacobs James M H), Toy airplane. U.S. Pat. No. 2,538,522A (Jackle Erwin K), Toy glider. U.S. Pat. No. 3,222,817A (Edward Brandstetter), Toy automatic wing folding catapult plane. U.S. Pat. No. 3,369,319A (David A. Brown), Toy glider with automatic wing converging means. U.S. Pat. No. 3,839,818A (Heggedal E), Glider with automatically releasing foldable wings. U.S. Pat. No. 4,759,736A (Off The Ground Models, Inc.), Folding wing glider. U.S. Pat. No. 4,863,413A (Schwarz Charles F), Bird shaped toy glider. U.S. Pat. No. 4,915,664A (Erik Bakker), Toy glider with wing converging mechanism. U.S. Pat. No. 5,423,706A (Chase; George W.), Toy aircraft glider with rotating and folding wings.
U.S. Pat. No. 7,077,359B2 (Uncle Milton Industries), Pneumatically launched folding wing glider toy.
The existing inventions use movable horizontal tail mechanism such as disclosed in the following patents: U.S. Pat. No. 2,597,521A (Pemberton J C), toy glider; U.S. Pat. No. 2,820,322A (White Frank H), Toy airplane glider;
U.S. Pat. No. 2,876,585A (Frank Zaic), Flying devices; U.S. Pat. No. 3,091,889 A (Frank Zaic), Flying devices; U.S. Pat. No. 4,282,675A (Stripling Jr Sheldon A), Automatic horizontal tail control for model glider.
There are so many devices and mechanisms successfully make toy glider fly higher as we have seen from above existing inventions, as we know heavier aircraft cannot fly higher, the maximum height that the glider can reach is depend on its total weight when under the same launch force, the existing mechanism installed for folding wings normally have relatively heavy structures for folding and opening the wings, thus the total weight increase a lot and affect flight performance inevitably. When we make a movable elevator by installing a mechanism on the tail which is a smaller and simple structure than folding wing's structure, however the center of gravity is changed easily because we add weight far from the center of gravity of the toy glider, therefore we have to put some weight ahead of its wings for rebalance, thus the total weight increase is not just the weight of the mechanism for the movable elevator only, the weight added in the front also count, maybe twice the weight increased.
The U.S. Pat. No. 5,383,805A (Tsai; Tzu-Jan J), Toy glider with adjustable flying path. Published in Jan. 24, 1995, is the my previous design, its movable horizontal tail is a self-biasing horizontal tail resiliently attached to a rear bottom portion of a fuselage by a restoring member, the problems are: (1) We have to press the front edge of the movable horizontal tail to make it keep horizontal under the fuselage before launch, its rear edge will shaft and change the horizontal status, that is because the horizontal tail will shake on the soft restoring member. (2) When flatten the horizontal tail in its front edge, tailgers must extend to the front from tail end, it is not comfortable for fingers to grasp, especially for children. Our improvement is arranging a slow restoring member on top of the fuselage, then we can squeeze the rear edge of the movable horizontal tail, it is much easier for children to hold before launch, besides, the present invention will make the movable horizontal tail tilt in a steady way via the connecting to its fixed wings, use the fixed wings as a hinge to make the movable horizontal tail swing up and down only.
So when designing a toy glider with the approach by movable horizontal tail, my goal is to build a lightweight, stable, functional and easy to operate one but not sacrifice the original flight performance of a toy glider.
For vertical climb and slowly glide flight, The fact is the vertical climb travels the first several seconds, then the rest flying time is for downwards glide. To get the vertical climb is to make the horizontal tail parallel to the fuselage axis as much as possible; the later gliding angle of the movable horizontal tail is a very small negative angle relative to the fuselage axis, if the negative gliding angle is too big, the toy glider will stall when gliding, so the angle change of the movable horizontal tail is a very small quantities, changes between small negative angle to horizontal angle. My design is to control the horizontal tail angle change by time schedule and make it only a small angle change between negative angle and near parallel angle relative to the fuselage axis, more clearly, for vertical catapult launch, we only need to make the horizontal tail to stay in nearly zero angle right before launch, release the toy glider for straight up fly for the first several seconds and then make the horizontal tail maintaining at a negative angles relative to the fuselage axis for the rest downward gliding condition.
To obtain above mentioned flight requirements, a slow rebound means is a choice to meet these demands and which is something that will slowly restore after flattened, examples are slow rebound foam, Plastic telescopic tube, rubber squeeze bulb, etc. Here we use slow rebound foam or we call it memory foam as the description name used for slow rebound means. The memory foam has two properties: (1) compressible and slow rebound, (2) sufficiently large restoring force, when it is pressed down, it will take several seconds form flattened state recover to its original unstressed state, we pick the right recovery time to match the catapult launch time schedule, that is, the compressible property allows the horizontal tail to be flattened close to zero angle relative to the fuselage axis within the first few seconds after launch, after that, the memory foam restore with a slow speed but sufficiently large restoring force to prop up the horizontal tail with negative angle relative to fuselage axis for slowly glide condition.
Our basic structure of toy glider has wings and horizontal tail integrated into one single piece of flight control surfaces and sticks it to the top surface of a fuselage, one or more vertical tail fixed on the top surface of the flight control surfaces. As we know with fixed horizontal tail cannot fly both straight line and circle locus in a catapult launch, so it is necessary to have a movable horizontal tail for straight line up and circular down flight. For making the fixed horizontal tail can move, place a wedge shaped memory foam in between the horizontal tail and the fuselage at the back end of the glider so that the horizontal tail is propped up by the memory foam and with negative angle to the wings, that is, its front edge is lower than the rear edge by front view, besides, the horizontal tail can move due to the compressibility of the memory foam. More important, the fixed front wings which on the fuselage works as a hinge for the horizontal tail and allows the horizontal tail tilt up and down stably. Before catapult launch, squeeze the back end of the glider by fingers, thus the horizontal tail is flattened and with zero angle to the fuselage, then launch the glider, it can fly as high as possible for seconds until the horizontal tail restore to its original negative angle by the expansion of the memory foam, then the glider starts to glide in a gentle way. During the catapult launch, the movable horizontal tail has changed from near-zero angles to negative angle by squeezing it and by let it go.
To enable the aircraft to fly higher, a further improvement is to let the horizontal tail to move not just start from near-zero angle to negative angle, but start from positive angle to negative angle. Although keep the positive angle for the horizontal tail will make toy glider a nose down arc locus when fly, but if we launch it vertically toward the sky or over ninety degree, the toy glider will still fly toward the sky with a nose down arc locus, when the horizontal tail moves to zero angle, the toy glider will fly straight up, when the angle reaches its maximum negative angle setting, the toy glider will fly toward the sky with a nose up arc locus, the procedure means the climbing time has increased so can make toy glider fly higher with S-shaped climbing locus.
For making the movable horizontal tail move from positive angle to negative angle, just cut off a wedge block at the back end upper surface of a straight fuselage, an inclined surface is formed on the tail end of the fuselage then, stick a wedge shaped memory foam which is larger than the wedge block be cut from the fuselage on the inclined surface, use the same method to assemble the rest parts of the toy glider and let the horizontal tail maintain at negative angle relative to the fuselage when finished. Now a movable horizontal tail can moves from positive angle to negative angle by squeeze it and by let it go.
The other benefit of the angle change from positive angle to negative angle relative to the angle change from zero angle to negative angle is that for a very small negative angle setting of a toy glider, the former has more space for more slow rebound foam material being stuffed, so the material will not be compressed to its limit therefore to reduce the fatigue of the materials. On the contrary, the latter can only stuff less slow rebound foam material to a very small wedge gap and will be fattened at every launch, the material may fatigue and cause weakening of restoring force.
Use memory foam can easily achieve the function of movable horizontal tail; moreover, it is so light that will cause minimal burden to any toy glider. Furthermore, the glider can also make a circle flight back to its launch point by just grab sides of the fuselage instead of squeeze the movable horizontal tail when launch, with the movable horizontal tail maintained at negative angle position, provides the user another game play.
Besides, by squeezing the memory foam for longer or shorter time, press deeper or shallower, which can change the rebounding time of the angle change of the movable horizontal tail, thus we can control the maximum height reached of each launch, and we can launch it horizontal, sideway or vertical to produce different flight radius for fun.
The structure of the movable horizontal tail is at the back end portion of the glider, completed with memory foam squeezed into the wedge gap of the fuselage and the flight control surfaces, the flight control surfaces which including wings and horizontal tail. The shape of the flight control surfaces is not limited, that is, we can design various shapes of gliders, as long as the gliders' center of gravity are well balanced, we can then put a piece of memory foam inside the wedge gap between the fuselage and the horizontal control surfaces, to produce a glider that can fly high and glide down slowly.
It is an advantage of the present invention to provide a toy glider fly to higher altitude and then gliding down.
Another advantage of the invention is arranging slow rebound foam to make existing toy glider's horizontal tail movable is very easy, as long as the upper surface of the fuselage is flat.
Another advantage of the invention is the movable horizontal tail works stably because control of angle change of the movable horizontal tail is only by the restoring property of slow rebound means and nothing to do with spring, launching speed, air resistance or gravity.
To build a movable horizontal tail glider, we starting from assembling basic aircraft components (see
For a glider fly high and then circling glide down, the flight path is the combination of the above two flying mode, we need a horizontal tail 22 which is able to move form flat condition (see
The shapes of the flight control surfaces 2 are unlimited, could be delta wings 21 as seen in
Another example is a traditional T-shaped tail glider with horizontal tail 22 mounted on a single vertical tail 23 as shown is
The other embodiment is setting a horizontal tail 22 which can move between positive angle to negative angle as shown in