Patent Publication Number: US-8109802-B2

Title: Toy helicopter having a stabilizing bumper

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 60/972,777 filed Sep. 15, 2007 entitled “Miniature Toy Helicopter Having Stabilizing Bumper”, incorporated by reference herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to motorized model or miniature toy helicopters. 
     In general, helicopters are flying machines with the ability to hover and fly forwards, backwards, and sideways. Toy helicopters, that replicate the motion of a real helicopter, are well known for providing amusement. However, when full-size helicopters are scaled down to model or miniature proportions, their small rotor systems are typically inefficient at producing lift and the rotor system is often drastically simplified resulting in less stable control. Toy helicopters are particularly unstable during take-off because the rotor blades are not at full speed when the lift generated by the rotor blades is sufficient to lift the lightweight device off of the ground. Having the support legs close to the geometric center of the vehicle, similar to a full scale model, allows the toy helicopter to take off at an angle. As a result, the toy will take off in an unstable or slanted state typically resulting in a crash or unintentional contact with another object. Additionally, because toy helicopters may be used indoors were there are walls and additional objects in close proximity, the rotor blades can hit a wall or other object causing the toy helicopter to crash. 
     What is therefore needed is a toy helicopter having improved stability, especially during take off and protection to the rotor blades during operation. 
     BRIEF SUMMARY OF THE INVENTION 
     Briefly stated, the present invention is directed to a toy helicopter which has a fuselage having a front end a rear end and two lateral sides. A main motor is supported from the fuselage. A main rotor is operably connected to the motor and has at least one rotor blade that rotates about a center axis generally laterally centered with respect to the fuselage. The at least one rotor blade is configured and positioned to provide lift and has a rotational path having a maximum radius. A bumper is fixedly connected to the fuselage, spaced entirely axially downwardly from the at least one rotor blade and extends radially outwardly from and at least partially around the fuselage. At least a portion of the bumper has a maximum radial dimension from the center axis at least as great as the maximum radius of the rotational path of the at least one rotor blade. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The foregoing summary, as well as the following detailed description of a preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings an embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. 
       In the drawings: 
         FIG. 1  is a perspective view of the upper right side of a toy helicopter having a stabilizing bumper in accordance with a first preferred embodiment of the present invention; 
         FIG. 2  is a top plan view of the toy helicopter having a stabilizing bumper shown in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of the left side of the toy helicopter having a stabilizing bumper taken along line  3 - 3  in  FIG. 1 ; 
         FIG. 4  is an exploded view of the toy helicopter having a stabilizing bumper of  FIG. 1 ; 
         FIG. 5  is a perspective view of the upper right side of a toy helicopter having a stabilizing bumper in accordance with a second preferred embodiment of the present invention; and 
         FIG. 6  is a top plan view of the toy helicopter having a stabilizing bumper shown in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Certain terminology is used in the following description for convenience only and is not limiting. The words “right”, “left”, “lower” and “upper” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of a toy helicopter in accordance with the present invention, and designated parts thereof. Unless specifically set forth herein, the terms “a”, “an” and “the” are not limited to one element but instead should be read as meaning “at least one”. The terminology includes the words noted above, derivatives thereof and words of similar import. 
     Referring to the drawings in detail, wherein like reference numerals indicate like elements throughout, there is shown in  FIGS. 1-4  a first preferred embodiment of a miniature toy helicopter having a stabilizing bumper (or simply “toy helicopter”)  10 . Though the toy helicopter  10  may resemble a real life helicopter vehicle, the toy helicopter  10  is not limited to a helicopter vehicle configuration and the toy helicopter  10  may be configured to resemble any flying vehicle capable of performing the functions as described herein. 
     With reference to  FIGS. 1-4 , the toy helicopter  10  comprises a fuselage  12  having a front end  12   a  a rear end  12   b  and two lateral sides  12   c . An imaginary center axis C extends through the fuselage  12  generally laterally centered with respect to the fuselage  12  between the two lateral sides  12   c . The fuselage  12  is preferably shaped as a helicopter cockpit having a decorative cover  52  but the fuselage  12  may be comprised of any shape and include or not include the cover  52  configured as a fuselage or cockpit. The cover  52  is preferably affixed to the fuselage  12  by an adhesive, welding or permanent fasteners such as rivets. However, the cover  52  may be integrally formed with the fuselage  12  or releasably connected to the fuselage  12  using a mechanical fastener or snap or the cover  52  may be otherwise removably mounted to the fuselage  12  to allow for interchange of different decorative covers  52  and/or allow for access to a cockpit (not shown) for placement of an object such as a toy pilot (not shown). The fuselage  12  preferably supports or houses an electric main motor  14  ( FIG. 3 ). The main motor  14  includes a pinion  16 . The pinion  16  is drivingly connected to a larger spur gear  18 . The spur gear  18  is attached to a drive shaft  20 . A chassis  46  holds the main electric motor  14 , the rotor shaft  20 , and a tail rod  34  together. 
     The fuselage  12  is preferably comprised of a lightweight material such as expanded polypropylene or polystyrene. However, the fuselage  12  may be comprised of any lightweight material such as a hollow or foam polymeric material or balsa wood. Alternatively, the fuselage  12  be comprised of a more rigid material or molded around the first electric motor  14 , the rotor shaft  20 , and the tail rod  34  such that the chassis  46  is not necessary. 
     A main rotor assembly  22  is attached to the drive shaft  20 . The drive shaft  20  extends upwardly from the fuselage  12  along the center axis C. The main rotor assembly  22  includes a main rotor  24  having first and second blades  24   a ,  24   b  coupled to the drive shaft  20  so as to rotate about the center axis C. The main rotor  24  has a rotational path P 1  having a maximum radius R 1  (see  FIG. 2 ). The first and second blades  24   a ,  24   b  are preferably identical in shape but are tilted or angled along their longitudinal length in opposite directions from each other such that rotation of the rotor  24  creates lift of the toy helicopter  10 . The first and second blades  24   a ,  24   b  are preferably integrally formed with a central hub  24   c  but may be separately formed and attached to a separate central hub element. The main rotor  24  may comprise more than two blades and may include additional stabilizer blades (not shown). The main rotor  24  is preferably partially pivotal around the longitudinal length of the main rotor  24  in order to work in conjunction with a stabilizing fly bar  26  to stabilize flight of the toy helicopter  10 . The fly bar  26  is shown axially spaced above the main rotor  24  such that the main rotor  24  is between the fuselage  12  and the fly bar  26  but the fly bar  26  may be coplanar with the main rotor  24  or spaced between the main rotor  24  and the fuselage  12 . The fly bar  26  preferably has a rotational path P 2  centered on the center axis C and a maximum radius R 2 . The maximum radius R 2  of the fly bar  26  is preferably less than the maximum radius R 1  of the main rotor  24 , but may be equal to or greater than the maximum radius R 1  of the main rotor  24 . The fly bar  26  is shown in  FIG. 3  to be split into two segments but the fly bar  26  may be a single element. A weight  32  is preferably provided at each end of the fly bar  26 . The weights  32  help to stabilize the toy helicopter  10  because the weighted fly bar  26  spinning about the center axis C will tend to rotate about a horizontal plane due to the centrifugal force created by the weights  32 . The fly bar  26  is attached to the drive shaft  20  by a fly bar head  28  and to the main rotor  24  by a pair of rotor linkages  30 . The fly bar head  28  permits the fly bar  26  to pivot about an axis that is perpendicular to the center axis C and the longitudinal length of the main rotor  24 . To permit the different pivotal movement of the rotor  24  and fly bar  26  to be linked, the central longitudinal axis of the fly bar is preferably angularly offset from the central longitudinal axis of the rotor, for example, about thirty degrees in advance of the leading edges of the rotor  24  (see  FIG. 2 ). The rotor linkages  30  join the fly bar  26  with the main rotor  24  so that they pivot in unison while the fly bar  26  and the main rotor  24  rotate together on the drive shaft  20  about the center axis C. 
     Though the above described rotor assembly  22  is preferred, it is within the spirit and scope of the present invention that any suitable rotor assembly be utilized for providing lift and stabilization of the toy helicopter  10 . For example, additional rotor blades (not shown) may be implemented either on the same plane as the rotor  24  or another rotor assembly (not shown) can be added axially spaced from the main rotor assembly  22 . The additional rotor may also be a short bladed stabilizing rotor substituted for the fly bar  26  to provide stabilization with lift. Alternatively, a stabilization ring (not shown) may be provided around the main rotor  24 , along the rotational path P 1  of the main rotor  24 , or supported independently on the draft shaft  20  above or below the main rotor  24 . It is preferred that the main rotor assembly  22  be constructed of a polymeric material. However, the main rotor assembly  22  may be constructed of nearly any lightweight material. If a short bladed stabilizing rotor is used, it can be made of a light weight material and weights may be added to the outer ends of its blade (not depicted). It is preferred that the drive shaft  20  and fly bar  26  be comprised of a rigid material such as metal, however the rotor shaft  20  and fly bar  26  may be constructed of any suitable material known in the art. 
     The tail  34  extends from the rear end  12   b  of the fuselage  12 . For weight consideration, the tail  34  is preferably comprised of a thin beam  35  such as a lightweight rod or a hollow, carbon fiber tube, but may be comprised of any size and shape and constructed of any lightweight material suitable for use with the power plan provided such as a polymeric material or aluminum. A tail rotor  36  is located proximate the distal end of the tail rod  34  and is operably connected to the rear end  12   b  of the fuselage  12  through the tail rod  35 . The tail rotor  36  includes at least a pair of tail rotor blades  36   a  that rotate about an axis generally perpendicular to the center axis C. The tail rotor  36  is preferably driven by an electric tail motor  38  supported from the tail rod  35 . Rotation of the tail rotor  36  exerts a tangent force on the tail rod  34  and rotates the fuselage  12  about the center axis C. 
     The front end  12   a  of the fuselage  12  is preferably weighted such that the toy vehicle  10  slants slightly toward the front end  12   a  and travels in the direction of the front end  12   a . The degree in which the toy vehicle slants may be controlled by adding a weight  70  (in phantom in  FIG. 1 ) on the toy vehicle  10 . The weight may be a piece of tape or an object attached by means of an adhesive or tape for adjustment. Alternatively or additionally, the weight  70  may be configured to be moved by the user along a track  72  for adjustment. Alternatively, the fuselage  12  could be weighted heavier toward the front end  12   a  and/or the tail rod  34  may include a slidably mounted weight (not shown) such that the weight distribution between the front end  12   a  and the rear end  12   b  can be adjusted by sliding the weight along the tail rod  34 . Preferably, the toy vehicle  10  is generally neutrally balanced for vertical flight and moves in a radial direction only from external forces such as wind or bouncing off objects or being pushed. However, the toy vehicle  10  may include a radial direction propulsion mechanism (not shown) such as an additional rotor or a slanting or slantable drive shaft. 
     The tail motor  38  is preferably reversible such that the tail rotor  36  can be driven in either rotational direction but may be unidirectional. Preferably, the tail  34  includes a vertical fin  40  provided proximate the tail rotor  36  as a rudder to inhibit precession of the fuselage  12  around the center axis C while providing protection to the tail rotor  36  in its radial direction. The fin  40  preferably extends at least partially circumferentially around a rotational path P 3  of the tail rotor  36  such that fin  40  prevents the tail rotor  36  from contacting objects in the radial direction (see  FIG. 3 ). 
     Referring to  FIGS. 3 and 4 , an electric power source  44 , preferably a rechargeable battery or capacitor, is suitably provided, for example on or within the fuselage  12 , to power the main and tail motors  14 ,  38 . A wire  38   a  preferably extends from the tail motor  38  along the tail rod  34  to the power source  44  positioned within the fuselage  12  ( FIG. 3 ). However, the tail motor  36  may include a separate power source (not shown). The fuselage  12  preferably includes an exposed power switch  42  for turning the toy helicopter  10  ON and OFF. 
     Referring to  FIGS. 1-4 , a bumper  48  is fixedly connected to the fuselage  12 . The bumper  48  is entirely spaced axially downwardly from the main rotor  24  such that an uppermost surface  48   a  is below, spaced axially downwardly from the main rotor  24 . The bumper  48  extends radially outwardly from and at least partially around the fuselage  12 . Preferably, the bumper at least partially supports the fuselage  12  from the support surface S prior to take off. At least a portion of the bumper  48  has a maximum radial dimension R 3  measured from the center axis C that is at least as great as the maximum radii R 1  and R 2  of the main rotor  24  and fly bar  26  to provide a wide base for stability during take off and to prevent the main rotor  24  from contacting objects in the radial direction. The bumper  48  acts as a support base that is wider than the typical landing gear of a full scale helicopter (not shown) where the landing gear extends relatively closely to the fuselage. The bumper  48  helps to decrease the slant of the toy vehicle  10  during take-off resulting from an unstable lift that is typical of a lightweight toy helicopter. The bumper  48  is preferably in the form of a ring  44  that extends around the front end  12   a , rear end  12   b  and lateral sides  12   c  of the fuselage  12  and extends at least partially axially downwardly from the fuselage  12  so as to support the fuselage on landing and take-off. The bumper  48  has a diametric dimension R 3  extending circumferentially around the entire bumper  48  that is at least as great as and preferably greater than the maximum diameter of the rotational path R 1  of the main rotor  24 . The outer periphery of the bumper  48  is preferably curved but the bumper  48  may have any suitable cross-sectional shape such as generally crescent, oval, triangular, square or spiked so long as at least a sufficient portion of the radially outermost surface of the bumper  48  extends at least as far as and preferably farther than the maximum radii R 1  and R 2  of the main rotor  24  and flybar  26 . The bumper  48  is preferably positioned on an imaginary plane generally perpendicular to the center axis C. While the depicted bumper  48  forms a closed loop, the bumper  48  may not be completely closed or uniform in radial-vertical cross-section as described further below. The bumper  48  should at least substantially extend radially farther than and at least substantially surround the fuselage  12 , the rotor  24  and fly bar  26  to prevent an object such as a vertical wall (not shown) from contacting the main rotor  24  during use. 
     When the toy vehicle  10  moving horizontally bumps into a vertical object such as a wall, the bumper  48  contacts the object and preferably rebounds the toy vehicle and/or permit the user to spin the toy vehicle around to flay away from the object without the main rotor  22  or fly bar  26  from contacting the object. The bumper  48  is axially spaced from the rotor assembly  22  such that the main rotor  24  is positioned vertically between the fly bar  26  and the bumper  48  and both the rotor  24  and fly bar  26  are located within the outer perimeter of the bumper  48  defined by tangential projection of the bumper  48  in the axial direction (i.e. parallel to the center axis C). The tail rotor  36  and tail fin  40  are preferably positioned radially outside of the bumper  48 . The bumper  48  preferably has an uniform axial thickness T and generally planar, inner and outer opposing, circumferential walls  48   a ,  48   b  such that the air flow A forced downward from the main rotor  24  is channeled down through the center of the bumper  48  to create a cylinder of air A′ pushed downward for creating lift of the toy helicopter  10 . 
     At least one, and preferably a plurality, of support arms or spokes  50  extend at least generally radially between the fuselage  12  and the bumper  48 . Although two support arms  50  are shown and preferred, the toy helicopter  10  may include more or fewer support arms  50 . The support arms  50 , along with the tail rod  34  and the front end  12   a  of the fuselage  12  connect the fuselage  12  with the bumper  48 . However, only one of the tail rod  34 , a support arm  50  or a portion of the fuselage  12  need to connect to the bumper  48 . The support arms  50  help to space, secure and stabilize the bumper  48  to and from the fuselage  12 . The support arms  50  also help to prevent turbulent and horizontal airflow from passing through the bumper  48  and helps to channel the airflow A in the vertical airflow A′ direction. Furthermore, one or more of the support arms  50  is preferably pitched or angled in the same direction as the pitch of the rotor blades  24   a ,  24   b  so that the downward airflow through the support arms  50  is converted into a torque on the fuselage  12  to rotate the bumper  48  in the same direction as the main rotor  22  and oppose the counter-torque developed by the main motor  14  and fuselage  12  in rotating the drive shaft  20 . The bumper  48  preferably includes notches  54  that are preferably decorative but may be shaped to reduce drag, minimize the effect of cross winds, reduce overall weight and/or impact the torque on the fuselage  12 . Additionally, a plurality of feet  58  extend downwardly from the bumper  48  below the bumper  48  and the fuselage  12  (see  FIG. 3 ) so as to raise the bumper  48  from a support surface S to help the airflow A′ from the main rotor  22  be directed through the vertically extending openings between the lateral sides  12   a ,  12   b  of the fuselage  12  and the bumper  48  prior to take off until sufficient force is created by the main rotor  22  to lift the toy helicopter  10  from the support surface S. 
     Referring to  FIG. 3 , the air flow A that is generated by the main rotor  24  projects in a variety of downward directions but once it is pushed through the bumper  48  the air flow A′ is primarily in a vertical or downward position. The bumper  48  and support arms  50  are preferably constructed of similar material as the fuselage  12  such as expanded polypropylene but it is within the spirit and scope of the present invention that the bumper  48  and support arms  50  be comprised of any lightweight material known in the art and that the bumper  48 , support arms  50  and fuselage  12  be separately or integrally formed and comprised of more than one material. 
     During use, a remote control (not shown) is provided at least with a throttle control member such as a button or toggle or slide and preferably a direction control member. The first electric motor  14  rotates in response to the throttle level selected and the second electric motor  38  which is preferably reversible, rotates in response to the direction and/or throttle selected. If desired, an adjustable trim control member can be provided to control the speed of the tail motor  38  at a nominal level which prevents the fuselage  12  from precessing. The toy helicopter  10  moves vertically upward at full throttle, hovers at a hover level throttle and moves vertically downward at a throttle less than the hover level. The toy helicopter  10  preferably is only controllable in the vertical and rotational directions as previously mentioned. Outside forces such as surrounding air flow and forces exerted on the bumper  48  move the toy helicopter  10  in the horizontal or transverse direction but such movement is somewhat inhibited by the inertia of the bumper  48 . The inability to remotely control the transverse direction helps to simplify the toy helicopter  10  and allows the toy helicopter  10  to translate only slightly or not at all making the toy helicopter better suited for indoor use. If horizontal translation is desired, the helicopter can be made slightly nose heavy as indicated previously, for example, by attaching a small weight such as a piece of tape on the bumper  48 , to tilt the toy helicopter slightly downward at the front end  12   a , which will cause translation in the direction of the tilt (i.e. movement in whatever is the forward direction of the toy helicopter  10 ). Though it is preferred that the translational movement be limited, it is also within the spirit and scope of the present invention that conventional translation controls (cyclic/collective) be provided for full movement control. 
     Referring to  FIGS. 4-6 , wherein similar numerals with a leading “2” correspond to similar numbers of the first embodiment  10 , there is shown a second preferred embodiment  210  of the present invention. The second embodiment  210  is similar to the toy helicopter of the first embodiment  10 , except as described below. 
     The toy vehicle  210  includes a bumper  248  comprised of first and second bumper sections  248   a ,  248   b  such that the bumper  248  is partially open toward the front end  212   a  and the rear end  212   b  of the fuselage  212 . The front end  212   a  of the fuselage  212  and the tail  234  each preferably extend radially farther from the center axis C than the rotational paths P 1  and P 2  of the main rotor  224  and the fly bar  226 . The bumper  248 , where present, preferably extends from the lateral sides  212   c  of the fuselage  212  radially outwardly at least as far as and preferably farther than the rotational paths P 1  and P 2  of the main rotor  224  and the fly bar  226 . Tangents T 1 , T 2  from the front end  212   a  of the fuselage  212  to the bumper sections  248   a ,  248   b  and tangents T 3 , T 4  from the bumper sections  248   a ,  248   b  to a portion  240   a  of the tail  234  are preferably also located outside of the rotational paths P 1  and P 2  whereby the rotational paths P 1  and P 2  are surrounded in the horizontal plane by the fuselage  212 , the bumper  248 , the tail assembly  234  and their tangents. The first and second sections  248   a ,  248   b  are preferably each crescent shaped in plan view and extend substantially past the rotational paths P 1  and P 2 . However, the bumper  248  may be any suitable shape and have more or fewer gaps around the fuselage  212 . 
     Additionally, the second embodiment of the toy helicopter  210  differs from the first embodiment of the toy helicopter  10  in that the second embodiment of the toy helicopter  210  has four support arms  250 , two for each bumper section  248   a ,  248   b , that extend from the fuselage  212  both radially and axially to sufficiently support first and second bumper sections  248   a ,  248   b  from the fuselage  212  and the raise the fuselage  212  off of the support surface S prior to take-off. However, the first and second bumper sections  248   a ,  248   b  may be connected with the fuselage  212  by one or more support arms  250  and need not extend in the axial direction. 
     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. The toy helicopter  10 ,  210  is preferably controlled via radio (wireless) signals from a remote control (not shown). However, other types of controllers may be used including other types of wireless controllers (e.g. infrared, ultrasonic and/or voice-activated controllers). Alternatively, the toy helicopter  10 ,  210  may be self-controlled with or without preprogrammed movement. The toy helicopter  10 ,  210  can be constructed of, for example, plastic, polystyrene or any other suitable material such as metal or composite materials. Also, the relative dimensions of the toy helicopter  10 ,  210  shown can be varied, for example making components of the toy helicopter  10 ,  210  smaller or larger relative to the other components. It is understood, therefore, that changes could be made to the preferred embodiments of the toy helicopter  10 ,  210  described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.