Patent Publication Number: US-2005121553-A1

Title: Toy radio-controlled helicopter

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a toy radio-controlled helicopter for which aeronautical maneuvers, such as forward and reverse flight and turns, can be easily controlled.  
      2. Related Background Art  
      Conventionally, for a common toy radio-controlled helicopter, a motor incorporated in the fuselage of the toy rotates a main rotor, attached to the top of the fuselage, and a tail rotor, which is attached to the end of a boom extending from the rear of the fuselage and which neutralizes reactive torque of the fuselage produced by the rotation of the main rotor. Further, a mechanism for tilting the rotating face of the main rotor of an aircraft to the front or the rear, and to the right or the left, is provided to permit the aircraft to fly forward or in reverse and to perform turns to the right or left. One well known toy radio-controlled helicopter, for which a tail rotor is not required, has a tail unit attached at the rear of the fuselage that generates lift in a direction that neutralizes the reactive torque of the fuselage produced by the main rotor during the flight (see, for example, patent document 1: JP-A-Hei 8-103571 (pp. 1-3 and FIGS. 1 to 5).  
      However, since for a conventional toy radio-controlled helicopter mechanisms for tilting the rotating face of the main rotor to the front or rear and to the right or left are provided that permit a radio controller to be used to control the flight of the aircraft, the structure and the control operation are complicated, and respectively increase the overall costs and render the remote piloting operation too difficult for a beginner to handle easily. Furthermore, although a tail rotor is not required and a simplified mechanism can be provided for a toy radio-controlled helicopter having a tail unit, attached to the rear of its fuselage, that generates lift to neutralize the reactive torque resulting from the rotation of the main rotor, such am aircraft may become unstable when forward flight is resumed while hovering, or when taking off, because lift for neutralizing the reactive torque is not generated at the tail unit.  
     SUMMARY OF THE INVENTION  
      To resolve these problems, it is one objective of the present invention to provide a toy radio-controlled helicopter having a configuration that includes a simplified piloting mechanism, for performing a complicated control operation for stabilizing flight performance, that can be manufactured at a low cost and that can easily be controlled, even by a beginner.  
      To achieve this objective, according to a first aspect of the invention, a toy radio-controlled helicopter comprises: 
          a main rotor, attached to the top of a fuselage and driven by an incorporated motor;     a tail rotor, attached to a tail unit at the end of a horizontal, elongated boom extending from the rear of the fuselage, that is driven by the motor;     a right moveable wing and a left movable wing, so attached to right and left side faces of the fuselage, below the main rotor, as to be movable by an actuator unit incorporated in the fuselage; and     a receiver, incorporated in the fuselage, for controlling the operations of the motor and the actuator. Since the right and left movable wings can be rotated, a simple mechanism can be used to perform a complicated operation, the flight performance can be stabilized, the configuration can be simplified and manufactured at a low cost, and even a beginner can perform the piloting operation.        

      According to a second aspect of the invention, as the actuator unit, a right actuator and a left actuator are incorporated in the fuselage and independently rotate the right movable wing and the left movable wing. Since the right and left actuators independently control the right and left movable wings, movement of the wings can be freely controlled.  
      According to a third aspect of the invention, as the actuator unit, one actuator, incorporated in the fuselage, employs a link mechanism to rotate the right and left movable wings in opposite directions. With this arrangement, only one actuator need be provided to control the rotation of the right and left wings.  
      According to a fourth aspect of the invention, the right and left movable wings are mounted on respectively included horizontally arranged shafts, extending inward from the right and left sides of the fuselage, that are coupled with the actuator unit, so that the right and left wings attached to the shafts are rotated from the vertical and are tilted to the front or to the rear. Since the right and left wings are rotated from the vertical so that they are tilted to the front or rear, a fore or aft displacement force is exerted on the aircraft by an induced flow of air produced by the main rotor, and the airframe can be moved forward or to the rear, or rotated to the right or left.  
      According to a fifth aspect of the invention, a rear wing is formed at the aft end of the tail unit to generate lift in the airflow produced by the rotation of the tail rotor. Since during flight, in the airflow produced by the tail rotor, the rear wing on the tail unit generates lift, the aft end of the tail unit is raised while the front, distal end of the fuselage is lowered, and the aircraft can move forward with the entire rotating face of the main rotor slightly tilted.  
      According to a sixth aspect of the invention, the tail rotor attached to the tail unit is tilted, rather than horizontal, so as to employ a horizontal component of the propulsive force exerted by the rotation of the tail rotor to neutralize, for the fuselage, the reactive torque resulting from the rotation of the main rotor, and so as to employ a vertical component of the same force to raise the aft end of the tail unit and lower the front, distal end of the fuselage. With this arrangement, the aircraft can move forward with the front, distal end of the fuselage lowered and the aft end of the tail unit raised, and the entire rotating face of the main rotor tilted slightly to the front.  
      Through the rotation of right and left movable wings attached to the right and left side faces of the fuselage of a toy radio-controlled helicopter, the configuration can be simplified and can be manufactured at a low cost, an uncomplicated mechanism can be employed to perform a complex control operation, the flight performance can be stabilized, and the piloting operation can be performed easily, even by a beginner. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of a toy helicopter according to a first embodiment of the present invention;  
       FIG. 2  is a plan view for explaining a driving system for the toy helicopter according to the first embodiment of the invention;  
       FIG. 3  is a side view for explaining the driving system of the toy helicopter according to the first embodiment;  
       FIG. 4  is a front view of the driving system of the toy helicopter according to the first embodiment of the invention;  
       FIG. 5  is a block diagram for explaining an operation for controlling the toy helicopter according to the first embodiment of the invention;  
       FIG. 6  is a diagram for explaining the forward flight of the toy helicopter according to the first embodiment of the invention;  
       FIG. 7  is a diagram for explaining the rearward flight of the toy helicopter according to the first embodiment of the invention;  
       FIG. 8  is a diagram for explaining the right rotational movement of the toy helicopter according to the first embodiment of the invention;  
       FIG. 9  is a diagram for explaining the left rotational movement of the toy helicopter according to the first embodiment of the invention;  
       FIG. 10  is a perspective view of a toy helicopter according to a second embodiment of the invention;  
       FIG. 11  is a rear view for explaining an example tail unit for the toy helicopter according to the present invention; and  
       FIG. 12  is a rear view for explaining another example tail unit for the toy helicopter according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      The present invention will now be described more specifically by referring to a first embodiment. FIGS.  1  to  5  are diagrams for explaining a toy radio-controlled helicopter according to the first embodiment.  FIG. 1  is a plan view for explaining the driving system of the toy helicopter,  FIG. 2  is a plan view for explaining the driving system of the toy helicopter,  FIG. 3  is a side view for explaining the driving system of the toy helicopter,  FIG. 4  is a front view for explaining the driving system of the toy helicopter, and  FIG. 5  is a block diagram for explaining an operation performed to control the toy helicopter.  
      For a toy helicopter  10  according to this embodiment, a main rotor  15  is attached to the top of a fuselage  11 ; landing members  12  are attached to the lower portion of the fuselage  11  for landing on the ground, for example; a horizontally elongated boom  13  is extended from the rear of the fuselage  11 ; a tail rotor  25  is attached to a tail unit  14  provided at the end of the boom  13 ; a right moveable wing  30  and a left movable wing  31  are rotatably attached to the right and left side faces of the fuselage  11 , below the main rotor  15 ; a receiver  40  is incorporated in the fuselage  11  to receive control signals from a transmitter  50 ; a motor  18  is incorporated in the fuselage  11  to drive the main rotor  15  and the tail rotor  25 ; and a right actuator  32  and a left actuator  33  are incorporated in the fuselage  11  to respectively drive the right and left movable wings  30  and  31  and permit aeronautical maneuvers to be freely controlled.  
      The fuselage  11 , which is composed of a light-weight material such as plastic, has a hollow, slightly elongated oval shape, and the landing members  12 , which are composed of the same plastic material and which are provided for landing on a plane surface, such as the ground, are attached to the lower right and left sides of the fuselage  11 . The end of a main rotor shaft  16 , which is vertically positioned, substantially in the center of the fuselage  11 , extends upward from the inside of the fuselage  11 . The main rotor  15 , which is made, for example, of plastic and which is used for aeronautical flight, is fitted over the upper end of the main rotor shaft  16 , and within the fuselage  11 , substantially at the center of the main rotor shaft  16 , a gear unit  17  is attached. The gear unit  17  includes a spur gear  17   a , formed around its outer circumference, and a bevel gear  17   b , formed on its upper, horizontal side face. The spur gear  17   a  engages a pinion  19 , which is fitted over the output shaft of the motor  18  incorporated in the fuselage  11 , so that as the output shaft of the motor  18  turns, the spur gear  17   a  turns the main rotor shaft  16  and the main rotor  15  is rotated. It should be noted that the main rotor  15 , when rotated by the motor  18 , provides sufficient lift to raise the fuselage  11 , the entire aircraft, and to perform flight.  
      The boom  13 , which linearly is hollow and is composed, for example, of plastic, is integrally attached to the rear of the fuselage  11 . One end of the boom  13  communicates with the interior of the fuselage  11 , while the other end extends aft, horizontally. The tail unit  14 , which is shaped like a case, is attached to the end of the boom  13 , and a rotatable, elongated tail rotor shaft  20  is inserted into the hollow portion of the boom  13 . One end of the rail rotor shaft  20  is extended into the fuselage  11 , and a bevel gear  21  fitted over that end engages the bevel gear  17   b  provided for the gear unit  17 . The other end of the tail rotor shaft  20  is extended into the tail unit  14 , where a bevel gear  23 , arranged inside the tail unit  14 , is fitted over it. The bevel gear  23  engages a bevel gear  22  in the tail unit  14  and one end of a short, rotary shaft  24 , provided for the bevel gear  22 , is extended outward, horizontally, from the tail unit, and the tail rotor  25  is attached to this extended end. Thus, as the motor  18  is operated and the gear unit  17  and the bevel gear  17   b  are rotated by the spur gear  17   a  that engages the pinion  19 , the tail rotor shaft  20  is turned by the bevel gear  21  that engages the bevel gear  17   b . Then, the shaft  24  is turned by the bevel gear  22  that engages the bevel gear  23  attached to one end of the tail rotor shaft  20 . It should be noted that, as will be described later in detail, the shaft  24  has a function whereby, when driven by the motor  18 , a force is generated to neutralize the reactive torque to which the fuselage  11  is subjected as a result of the rotation of the main rotor  15 .  
      The right moveable wing  30  and the left movable wing  31  are rotatably attached to the right and left sides of the fuselage  11  below the main rotor  15 . The right movable wing  30  and the left movable wing  31  respectively include shafts  34  and  35 , the ends of which are horizontally projected outward from the right and left side faces of the fuselage  11 , and a right wing  36  and a left wing  37 , which are attached to the projected portions of the shafts  34  and  35 . Inside the fuselage  11 , the other ends of the shafts  34  and  35  are connected to the incorporated right and left actuators  32  and  33 . The right and left wings  36  and  37  are, for example, thin, flat rectangular plates formed of plastic, and have sufficient transverse width to receive the airflow produced by the main rotor  15  above, and are small enough that they do not contact the fuselage  11  or the landing members  12  when they are rotated by the shafts  34  and  35 . Further, the right and left wings  36  and  37  are so attached to the fuselage  11  that their surfaces are vertical when they are not driven by the right and left actuators  32  and  33 . Thus, the right and left movable wings  30  and  31  are pivoted by the right and left actuators  32  and  33 , and from the vertical, can be independently tilted to the front or the rear by the shafts  34  and  35  to the front or rear  
      Further, the fuselage  11  also includes the receiver  40  for receiving radio control signals from the transmitter  50 , and a battery  46  for supplying power to the receiver  40 , the motor  18  and the right and left actuators  32  and  33 .  
      The receiver  40  includes: an antenna  41 ; a reception circuit  42 , for receiving radio control signals from the transmitter  50 ; a control circuit  43 , for generating control signals based on the signals received by the reception circuit  42 ; a motor drive circuit  44 , for driving the motor  18  based on the control signals output by the control circuit  43 ; and an actuator drive circuit  45 , for driving the right and left actuators  32  and  33 . With this arrangement, when a power switch  47  that is attached to the fuselage  11  and is used for control is turned on, power is supplied by the battery  46  to the reception circuit  42 , the control circuit  43 , the motor drive circuit  44  and the actuator drive circuit  45 . The transmitter  50  includes: a controller  51 , having control levers for controlling the heading, such as rising or descending, forward or rearward flight, or turns; a signal generation circuit  52 , for generating a control signal in accordance with the manipulation of the controller  51 ; and a transmission circuit  53  for transmitting, as a radio signal, the control signal generated by the signal generation circuit  52 . With this arrangement, when a power switch  55  is turned on, power is supplied by a battery  54  to the signal generation circuit  52  and the transmission circuit  53 .  
      The operation of the thus arranged toy helicopter  10  will now be described. FIGS.  6  to  9  are diagrams for explaining the operation of the toy helicopter  10 .  FIG. 6  is a diagram for explaining the forward flight of the toy helicopter  10 ,  FIG. 7  is a diagram for explaining the rearward flight of the toy helicopter  10 ,  FIG. 8  is a diagram for explaining a right turn performed by the toy helicopter  10 , and  FIG. 9  is a diagram for explaining a left turn performed by the toy helicopter  10 .  
      In order to operate the toy helicopter  10 , first, the power switch  47  provided for the fuselage  11  is turned on, and the lower portions of the landing members  12  are placed on flat ground, for example, to prepare for the takeoff of the fuselage  11 . Then, when the power switch  55  of the transmitter  50  is turned on, and the control lever of the controller  51  is manipulated, the signal generation circuit  52  generates a control signal corresponding to the manipulation, and the transmission circuit  53  transmits a radio control signal through an antenna  56 . The control signal transmitted by the transmitter  50  is received, through the antenna  41 , by the reception circuit  42  of the receiver  40  that is incorporated in the fuselage  11  of the toy helicopter  10 . The control signal, which has been transmitted from the transmitter  50  and received by the reception circuit  42 , is transmitted to and amplified by the control circuit  43 . The control circuit  43  generates a signal obtained by changing the pulse width and the cycle of the resultant signal, and outputs this signal to the motor drive circuit  44 . The motor drive circuit  44  generates a drive signal to drive the motor  18 , and based on this drive signal, the motor  18  starts to rotate. At this time, in accordance with a rising instruction signal, the right and left wings  36  and  37  of the right and left moveable wings  30  and  31  are maintained in the vertical state by the right and left actuators  32  and  33 . The rotation of the motor  18  is transmitted by the pinion  19 , through the spur gear  17   a  and the main rotor shaft  16 , to the main rotor  15 , which then starts rotating. At the same time, the rotation of the motor  18  is also transmitted by the pinion  19 , through the bevel gear  17   b , the bevel gear  21 , the tail rotor shaft  20 , the bevel gear  23  and the shaft  24 , to the tail rotor  25 , which then starts rotating. When the main rotor  15  and the tail rotor  25  are rotated by the motor  18 , the main rotor  15  generates a downward airflow while the tail rotor  25  exerts a force for neutralizing the reactive torque that is generated by the rotation of the main rotor  15 . As a result, the fuselage  11  takes off from the land and begins to rise.  
      When the fuselage  11  has risen to a predetermined height, and when the control lever of the controller  51  is manipulated for forward flight, as is described above, the transmitter  50  transmits a forward flight control signal that the reception circuit  42  receives. Similarly, the actuator drive circuit  45  generates a drive signal, and the right and left actuators  32  and  33  of the right and left moveable wings  30  and  31  are driven in accordance with this drive signal. Then, as is shown in  FIG. 6 , the shafts  34  and  35  are rotated, and accordingly, the right and left wings  36  and  37  are tilted from the vertical toward the front. The airflow produced by the main rotor  15 , exerts a propulsive force on the right and left wings  36  and  37 , which are tilted to the front, and the fuselage  11  begins to fly forward. When, as is shown in  FIG. 6 , the main rotor  15  is rotated in a direction indicated by an arrow A, a reactive torque, generated in the direction indicated by an arrow B, acts on the fuselage  11 , while as the tail rotor  25  is rotated an antitorque is generated, in the direction indicated by an arrow D, to neutralize a an torque that occurs in the tail unit  14  in the direction indicated by an arrow C, which corresponds to the direction indicated by the arrow B. As a result, the fuselage  11  is stably operated without spinning.  
      When the control lever of the controller  51  is manipulated for rearward flight, as is described above, the transmitter  50  transmits a rearward flight control signal that the reception circuit  42  receives. Similarly, the actuator drive circuit  45  generates a drive signal, and the right and left actuators  32  and  33  of the right and left moveable wings  30  and  31  are driven. Then, as is shown in  FIG. 7 , the shafts  34  and  35  are rotated, and accordingly, the right and left wings  36  and  37  are tilted from the vertical to the rear. The airflow produced by the main rotor  15 , exerts a propulsive force on the right and left wings  36  and  37 , which are tilted to the rear, and a rearward movement force is exerted on the right and left wings  36  and  37 . As a result, the fuselage  11  begins to move to the rearward.  
      When the control lever of the controller  51  is manipulated for a right turn, as is described above, the transmitter  50  transmits a right turn control signal that is received by the reception circuit  42 . Similarly, the actuator drive circuit  45  generates a drive signal, and the right and left actuators  32  and  33  of the right and left movable wings  30  and  31  are driven in accordance with this drive signal. Then, as is shown in  FIG. 8 , the shafts  34  and  35  are rotated, and the right wing  36  is to the rear from the vertical position, while the left wing  37  is tilted to the front from the vertical position. The airflow produced by the main rotor  15  exerts a rearward force on the right wing  36  and a propulsive force on the left wing  37 . As a result, the entire fuselage  11  starts a right turn.  
      When the control lever of the controller  51  is manipulated for a left turn, as is described above, the transmitter  50  transmits a left turn control signal that the reception circuit  42  receives. Similarly, the actuator drive circuit  45  generates a drive signal, and the right and left actuators  32  and  33  of the right and left movable wings  30  and  31  are driven in accordance with this drive signal. Then, as is shown in  FIG. 9 , the shafts  34  and  35  are rotated, and the right wing  36  is tilted from the vertical position to the front, while the left wing  37  is tilted from the vertical position to the rear. The airflow produced by the main rotor  15  exerts a propulsive force on the right wing  36  and a rearward force on the left wing  37 . As a result, the entire fuselage  11  starts a left turn.  
      For the toy helicopter  10  with the above described configuration, the main rotor  15  rotated by the motor  18  is provided on the top of the fuselage  11 ; the tail rotor  25  rotated by the motor  18  is provided at the end of the boom  13  extended from the rear of the fuselage  11 ; and the right and left movable wings  30  and  31  are attached on the right and left sides of the fuselage  11  and are be rotated by the right and left actuators  32  and  33  that are incorporated in the fuselage  11 . The receiver  40  incorporated in the fuselage  11  receives a control signal from the transmitter  50 , and the right and left actuators  32  and  33  are independently rotated to control the tilting angles of the right and left wings  36  and  37 . As a result, since the airflow produced by the main rotor  15  acts on the right and left wings  36  and  37 , forward flight, rearward flight and right and left turns can be performed. Since the right and left movable wings  30  and  31  are attached to the right and left sides of the fuselage  11  and are rotated by the right and left actuators  32  and  33 , the structure and the control can be simplified, compared with a mechanism for tilting the rotating face of the main rotor  15 , and the manufacturing costs can be reduced. Furthermore, since the right and left wings  36  and  37  are provided for the right and left sides of the fuselage  11 , stabilized flight can be attained. Further, the remote piloting operation can be even more simplified by using the control lever of the controller  51 , and even beginner can easily control the aircraft. In addition, according to this embodiment, the same main rotor  15  as is conventionally used is attached to the end of the boom  13  extended from the rear of the fuselage  11 , the aircraft can stably resume flight from the hovering state, or can stably take off.  
       FIG. 10  is a perspective view of a toy radio-controlled helicopter according to a second embodiment of the present invention. The same reference numerals as used for the first embodiment are also employed to denote corresponding parts and members, and no further explanation for them will be given.  
      For a toy helicopter  60  for the second embodiment, right and left movable wings  30  and  31 , provided in the same manner as for the first embodiment, are rotated by a single actuator  61  that is incorporated in a fuselage  11 . In the actuator  61 , a lever  63  extended horizontally is fitted in a rotary shaft  62  that is located upright in the center of the fuselage  11 , and the ends of link rods  64  and  65  are connected to the right and left ends of the lever  63 . Shafts  34  and  35  for the right and left movable wings  30  and  31  are extended inward into the fuselage  11 , and their ends are fixed to the ends of connection rods  65  that are extended upward. The other ends of the connection rods  65  are connected to the other ends of the corresponding link rods  64 . That is, the rotation of the rotary shaft  62  of the actuator  61  is transmitted at the same time to the shafts  34  and  35  from the lever  63  to the connection rods  65  and the link rods  64 , which constitute a link mechanism, so that the shafts  34  and  35  are rotated in opposite directions. The other configuration is the same as that for the first embodiment.  
      For the thus arranged toy helicopter  60 , only one actuator  61  need be employed to rotate the right and left movable wings  30  and  31 , which are attached in the same manner as for the first embodiment, in order to perform a right turn or a left turn. According to this embodiment, since one actuator  61  is employed to control the right and left movable wings  30  and  31 , the control operation can be simplified and the weight of the entire fuselage  11  can be reduced. Furthermore, as well as in the first embodiment, the flight maneuvers performed by the helicopter  60  can be stabilized, and the remote piloting operation can be simplified so that even a beginner can easily control the toy helicopter  60 . In this embodiment, forward flight and rearward flight can not be controlled by the rotation of the right and left wings  30  and  31 . However, for example, the rotating face of the main rotor  15  need only be tilted slightly to the front, so that forward flight can be performed.  
       FIGS. 11 and 12  are diagrams for explaining a toy helicopter having an improved tail rotor.  FIG. 11  is a rear view for explaining an example tail unit for the toy helicopter, and  FIG. 12  is a rear view for explaining another example tail unit for the toy helicopter. The same reference numerals as used for the first and second embodiments are also employed to denote corresponding parts and members, and no further explanation for them will be given.  
      As is shown in  FIG. 11 , a rear wing  71  is provided at the end of the tail unit  14  for the first and second embodiments, and generates lift when an airflow is produced by the rotation of a tail rotor  24 . During flight, lift is generated by the airflow produced by the tail rotor  24  as it passes over the rear wing  71  and is exerted on the tail unit  14 . With this lift, the head of the fuselage  11  is lowered, the tail unit  14  is raised, and the rotating face of the main rotor  15  is tilted slightly to the front. As a result, the aircraft can move forward.  
      As is shown in  FIG. 12 , a tail rotor  25 ′ of a tail unit  14 ′, which is formed in the same manner as for the first and second embodiments, is fitted over a shaft  24 ′, and the shaft  24 ′ is tilted at an angle θ from the horizontal. As the tail rotor  25 ′ is rotated, a propulsive force, exerted in the direction indicated by an arrow E at the angle θ, acts on the tail unit  14 ′. Of the propulsion force, a horizontal component force in the direction indicated by an arrow F neutralizes the torque that is generated in the fuselage  11  by the main rotor  15 , while a vertical component force in the direction indicated by an arrow G lowers the head of the fuselage  11  and raises the tail unit  14 ′. As a result, since the entire rotating face of the main rotor  15  is tilted slightly to the front, the aircraft can move forward.  
      The structures of the tail rotor shown in  FIGS. 11 and 12  can be employed for the toy helicopters  10  and  60  in the first and second embodiments. Since either of the structures can be employed for the tail rotor, forward flight can be easily obtained while the head of the fuselage  11  is lowered and the tail unit is raised slightly.  
      For the first and second embodiments, the shapes and sizes of the fuselage  11 , the boom  13 , the tail unit  14  and the right and left wings  36  and  37  can be arbitrarily designated, and are not limited to those for the embodiments.  
      The present invention can be employed for a toy radio-controlled helicopter for which such aeronautical maneuvers as forward flight, rearward flight and turns are controlled.