Abstract:
An air-cushion vehicle toy [1] includes a first motor [3b] for driving a propeller fan [3a], a second motor [4b] for driving a hovering fan [4a], and a body [1a] detachably mounted on a chassis [1b], on which a power supply [5a] is supported, and covering the upper surface of the chassis [1b] with various components supported thereon. The air-cushion vehicle toy [1] further includes a power cutoff mechanism [5] for breaking a power supply circuit to deenergize the first and second motors when the body [1a] is removed from the chassis [1b].

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an air-cushion vehicle toy. 
     2. Description of the Relevant Art 
     Air-cushion vehicle toys such as Hovercraft toys are supported aloft by a downward air thrust and propelled forward by a rearward air thrust. Such an air-cushion vehicle toy has a base comprising a chassis which supports thereon a propelling fan, a drive motor for the propelling fan, a hovering fan, a drive motor for the hovering fan, a battery as a power supply for the drive motors, and other members. These components mounted on the chassis are covered with a body mounted on the chassis. The body has an air inlet and an air outlet, each in the form of slits or a hole with a grid. To produce efficient propelling forces, the propelling fan generally comprises a large-size propeller fan of the exposed type. The lower surface of the chassis has a skirt extending along the peripheral edge thereof, for guiding the air thrust from the hovering fan downwardly. 
     When the body is removed from the chassis for battery replacement or other servicing, the battery and other components are exposed. If the control switch is turned on by mistake at this time, or if a new battery is connected while the control switch is being turned on, then the propeller fan is energized, causing the toy to move around. When this happens, it not easy to turn off the control switch. 
     The propeller fan and the hovering fan are directly connected to the shafts of their motors, respectively, and the motors are installed on the chassis. Each of the motors is installed on the chassis by an attachment seat on the chassis and an attachment member which holds the motor down on the attachment seat. The attachment member has both ends screwed to the chassis. The motors can be mounted on or dismounted from the chassis when the attachment members are fastened or released by tightening or loosening the screws. 
     The structure by which the motors are installed on the chassis thus includes small elements such as the screws and their washers, and hence is composed of a large number of parts, can only be assembled in a relatively complex process and over a long period of time, and, as a result, is relatively highly costly. If the existing motors are to be replaced with motors of higher power requirements in order to modify the air-cushion vehicle toy, then tools such as screwdrivers are needed to tighten and loosen the screws, and the screws and washers tend to be lost. 
     With the conventional air-cushion vehicle toy, the air thrust which is directed downwardly by the skirt does not produce well-balanced floating or hovering forces. Therefore, when the air-cushion vehicle toy is in operation, it is apt to be tilted, bringing one side of the toy into contact with the surface of water underneath the toy, so that the toy cannot run as desired, or the toy tends to lose stability when lifted aloft. 
     The present invention has been made in an effort to effectively solve the aforesaid problems of the conventional air-cushion vehicle toy. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an air-cushion vehicle toy which has means for preventing motors from being energized by mistake when a body is removed from a chassis for battery replacement or other servicing. 
     Another object of the present invention is to provide an air-cushion vehicle toy which has a motor attachment structure that is constructed of a reduced number of components, can easily be assembled, and is low in cost. 
     Still another object of the present invention is to provide an air-cushion vehicle toy which produces a downward air thrust directed by a skirt, thereby generating well-balanced lifting forces, so that the air-cushion vehicle toy is prevented from being tilted when lifted aloft. 
     According to he present invention, there is provided an air-cushion vehicle toy comprising a chassis, a propeller fan mounted on the chassis, a first motor mounted on the chassis, for driving the propeller fan, a hovering fan mounted on the chassis, a second motor mounted on the chassis, for driving the hovering fan, a power supply mounted on the chassis and selectively connectable to the first motor and the second motor, for energizing the first motor and the second motor, the power supply and the first and second motors constituting a power supply circuit, a body detachably mounted on the chassis in covering relation to the propeller fan, the first motor, the hovering fan, the second motor, and the power supply, and a power cutoff mechanism disposed in the power supply circuit, for breaking the power supply circuit to de-energize the first and second motors, when the body is removed from the chassis, and for making the power supply circuit when the body is attached to the chassis. 
     The air-cushion vehicle toy further includes a first motor attachment structure by which the first motor is installed on the chassis, and a second motor attachment structure by which the second motor is installed on the chassis, the first motor attachment structure comprising a first holder frame mounted on the chassis and accommodating the first motor, the first holder frame having at least one recess, and a first attachment attached to the first holder frame to secure the first motor and having at least one resilient finger which resiliently engages in the recess in the first holder frame, the second motor attachment structure comprising a second holder frame mounted on the chassis and accommodating the second motor, the second holder frame having at least one recess, and a second attachment attached to the second holder frame to secure the second motor and having at least one resilient finger which resiliently engages in the recess in the second holder frame. 
     The air-cushion vehicle toy also has a skirt mounted on a lower surface of the chassis, the skirt defining a pressure space for ejecting downwardly of the toy part of air under pressure delivered by the hovering fan, the skirt having a plurality of holes for ejecting the remainder of the air under pressure delivered by the hovering fan, the holes being defined in a lower surface thereof and arranged in surrounding relation to the pressure space when viewed in plan. 
     The above and further objects, details and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment thereof, when read in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of an air-cushion vehicle toy according to a preferred embodiment of the present invention; 
     FIG. 2 is a perspective view of an attachment for a motor for a propeller fan in the air-cushion vehicle toy shown in FIG. 1; 
     FIG. 3 is a cross-sectional view taken along line III--III of FIG. 2; 
     FIG. 4 is a perspective view of a power cutoff mechanism; 
     FIG. 5 is a plan view of the power cutoff mechanism; 
     FIGS. 6A and 6B are side elevational views of the power cutoff mechanism; 
     FIG. 7 is an exploded perspective view of a skirt of the air-cushion vehicle toy; and 
     FIG. 8 is a vertical cross-sectional view of the air-cushion vehicle toy. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in FIG. 1, an air-cushion vehicle toy, generally designated by the reference numeral 1, according to preferred embodiment of the present invention generally comprises a chassis 1b serving as a toy base, a body 1a covering the upper surface of the chassis 1b, and a skirt 1c attached to the lower surface of the chassis 1b. 
     The body 1a has two downward flexible fingers 2a, 2b on respective front and rear ends thereof. The chassis 1b has holes 2c, 2d defined in respective front and rear ends thereof for receiving the respective fingers 2a, 2b therein. An air inlet hole 2h in the form of slits is defined in upper and opposite side surfaces of a rear portion of the body 1a, and an air outlet hole 2i having grids is defined in a rear surface of the rear portion of the body 1a. A laterally swingable steering rudder 2j is attached to the rear end of the body 1a behind the air outlet hole 2i. 
     A motor 3b with a propeller fan 3a fixed to its rotatable shaft is mounted on a rear portion of the chassis 1b by an attachment structure 3 which comprises a holder frame 3c that accommodates the motor 3b therein and an attachment 3d, the holder frame 3c being installed on the chassis 1b. As shown in FIGS. 2 and 3, the attachment 3d, which is made of a flexible material, has an inverted channel-shaped cross section. The attachment 3d has a central tongue which includes a tooth 3e on its lower surface, which is resiliently held against an upper surface of the motor 3b, holding the motor 3b against the holder frame 3c. The attachment 3d also has a pair of laterally spaced resilient fingers 3f on the lower ends of its laterally spaced legs, the fingers 3f resiliently engaging respectively in recesses 3g that are defined in lateral side walls of the holder frame 3c. 
     A hovering fan 4a for producing a downward air thrust is mounted on the rotational shaft of a motor 4b which is installed on a front portion of the chassis 1b. 
     The motor 4b is installed on the chassis 1b by an attachment structure 4 which comprises a holder frame 4c that accommodates the motor 4b therein and an attachment 4d, the holder frame 3c being installed on the chassis 1b. The attachment 4d is made of a flexible material and has a central tongue which includes a tooth 4e on its lower surface, which is resiliently held against an upper surface of the motor 4b, holding the motor 4b against the holder frame 4c . The attachment 4d also has a pair of laterally spaced fingers 4f on the lower ends of its laterally spaced legs, the fingers 4f engaging respectively in recesses 4g that are defined in lateral side walls of the holder frame 4c. In order not to adversely affect the stability of the toy 1 when it hovers, the hovering fan 4a comprises a multiblade fan whose axis is oriented horizontally. The fan 4a is covered with a casing 4h which is integral with the attachment 4d and fittingly joined to an air duct 4i which is defined in the chassis 1b behind the holder frame 4c and communicates with the space below the chassis 1c. 
     The chassis 1b has a battery holder 5b for holding batteries 5a. A control switch 5c is mounted on one side of the chassis 1b laterally of the battery holder 5b, the control switch 5c having a knob projecting laterally outwardly from the chassis 1b. The control switch 5c can be angularly shifted to one, at a time, of three positions, i.e., &#34;STOP&#34;, &#34;HOVER&#34;, and &#34;HOVER/RUN&#34;. 
     As shown in detail in FIGS. 4, 5, 6A, and 6B, the toy 1 has a power cutoff mechanism 5, which comprises a fixed contact 5e of the battery holder 5b, a movable contact 5d positioned near a side of the battery holder 5b and normally spaced from the fixed contact 5e, and an engaging member end 5f projecting inside the body 1a for engaging the movable contact 5d. The movable contact 5d has an end fastened to the chassis 1b and electrically connected to a power wire 5g. The power wire 5g is connected through the control switch 5c to the motors 3b, 4b, thereby constituting a power supply circuit. As shown in FIG. 6A, when the body 1a is attached to the chassis 1b, bringing the engaging member end 5f into engagement with the movable contact 5d, the movable contact 5d contacts the fixed contact 5e, making the power supply circuit. When the body 1a is removed from the chassis 1b, lifting the engaging member end 5f out of engagement with the movable contact 5d, the movable contact 5d is shifted out of contact with the fixed contact 5e, braking the power supply circuit, as shown in FIG. 6B. 
     As illustrated in FIGS. 7 and 8, a float 6a made of polystyrene foam is fixedly attached to the peripheral edge of the lower surface of the chassis 1b. The float 6a serves to float the toy 1 on water and keep the toy 1 horizontal in the floating position. 
     A skirt 1c is attached to the lower surface of the chassis 1b through a substantially rectangular attachment plate 7a. The skirt 1c is positioned beneath the float 6a, and is in the form of a bag of thin film made of soft resin. 
     The attachment plate 7a has a lower frame 7b on its lower side. The skirt 1c has upper and lower central opening edges which are vertically spaced from each other and hermetically joined respectively to a lower peripheral edge of the attachment plate 7a and a lower peripheral edge of the lower frame 7b, thereby defining a rectangular annular inner opening 7c (FIG. 8). The lower frame 7b has an open lower side, defining an open space 7d below the attachment plate 7a. When viewed in plan, the space 7d contains the battery holder 5b, and hence the center of gravity of the toy 1. The air duct 4i which projects downwardly through the chassis 1b and serves as an air flow guide, extends through the attachment plate 7a into the inner opening 7c within the skirt 1c. 
     The skirt 1c has a number of small holes 7e defined in a lower layer thereof and spaced radially outwardly from the space 7d in surrounding relation thereto when viewed in plan. Air which is delivered into the skirt 1c by the hovering fan 4a is ejected downwardly from the small holes 7e. The skirt 1c, the attachment plate 7c, and the lower frame 7b are constructed as a unitary structure. Therefore, the skirt 1c is affixed to the chassis 1b when fingers 7f of the attachment plate 7a engage in holes 7g in the chassis 1b and the attachment plate 7a is fastened to the chassis 1b by a screw (not shown) threaded into an attachment hole 7h which is defined in the front portion of the chassis 1b. 
     Operation of the air-cushion vehicle toy 1 thus constructed will be described below. 
     When the front and rear fingers 2a, 2b of the body 1a (FIG. 1) are fitted respectively in the front and rear holes 2c, 2d in the chassis 1b, the body 1a is fixed to the chassis 1b, thus covering the upper surface of the chassis 1b. The body 1a can be detached from the chassis 1b when the fingers 2a, 2b are removed from the holes 2c, 2d. 
     When the fingers 3f of the attachment 3d of the attachment structure 3 engage respectively in the recesses 3g in the holder frame 3c, the tooth 3e (FIG. 3) resiliently presses down the motor 3b, which is thus fixed in place. At the time of installing the motor 3b in the holder frame 3c, the motor 3b is oriented with respect to terminals (not shown) on the bottom of the holder frame 3c, and then the attachment 3d is placed over the motor 3b and pressed against the motor 3b. In this manner, the motor 3b is electrically connected to the power supply circuit at the same time that the motor 3b is installed in the holder frame 3c. 
     The motor 3b can subsequently be detached from the holder frame 3c by spreading apart the fingers 3f outwardly and pulling the attachment 3d away from the holder frame 3c. 
     As with the attachment structure 3, the attachment structure 4 allows the motor 4b to be easily attached to and detached from the chassis 1b. 
     The casing 4h, which is integral with the attachment 4d of the attachment structure 4, is securely joined to the air duct 4i, thus guiding an air flow produced by the hovering fan 4a downwardly of the chassis 1b. 
     As shown in FIG. 6A, when the body 1a is mounted on the chassis 1b, the engaging member end 5f of the body 1a engages the movable contact 5d, laterally shifting the movable contact 5d into contact with the fixed contact 5d. As a result, the electric energy of the batteries 5a can be supplied through the power wire 5g to the motors 3b, 4b. 
     As shown in FIG. 6B, when the body 1a is dismounted from the chassis 1b, the engaging member end 5f is spaced from the movable contact 5d, which springs back out of contact with the fixed contact 5e. As a consequence, the motors 3b, 4b are disconnected from the batteries 5a and hence de-energized. 
     The air-cushion vehicle toy 1 is used as follows: 
     When the toy 1 is placed on a surface such as a surface of water and the control switch 5c is shifted to the &#34;HOVER&#34; position, the motor 4b for the hovering fan 4a is energized, and the hovering fan 4a is rotated. Air under pressure is now delivered by the hovering fan 4a through the air duct 48 into the open space 7d below the chassis 1b. Since the space 7d is closed at its lower side by the surface on which the toy 1 is placed, most of the air supplied from the air duct 48 fills up the open space 7d. A portion of the air is also sent through the opening 7c into the skirt 1c itself, inflating the skirt 1c downwardly into a substantially doughnut shape. The space 7d now functions as a pressure chamber or a floating force generating chamber. When the pressure of the air filled in the open space 7d increases in excess of a predetermined pressure, there is developed a floating force which is large enough to float or hover the toy 1. At the same time, the air filled in the skirt 1c itself is ejected through the small holes 7e downwardly toward the surface on which the toy 1 is placed. 
     The air which is ejected downwardly from the small holes 7e is effective either to lift aloft the toy 1 when the skirt 1c is in contact with the surface on which the toy 1 is placed, or to generate an air curtain layer which shields the air flowing downwardly from the space 7d when the toy 1 has already been lifted aloft and the skirt 1c is spaced from the surface over which the toy 1 is hovering. More specifically, when the toy 1 is lifted aloft, the air ejected from the small holes 7e produces an air layer of relatively high pressure between the lower surface of the skirt 1c and the surface over which the toy 1 is hovering. The high-pressure air layer surrounds the open space 7d when viewed in plan. Therefore, the air under pressure in the space 7d, which serves as a floating force generating chamber, is prevented from locally leaking out of the space 7d. As a result, the generated floating force is well balanced, and free of localized intensity variations. The air curtain layer has a certain width in the radially outward direction, which is also effective in preventing the air under pressure in the space 7d from locally leaking out of the space 7d. Since the small holes 7e are disposed closely to the center of the bottom of the skirt 1c, i.e., near the open space 7d, the air ejected from the small holes 7e also serves to effectively increase the air pressure in the space 7d. 
     The rotatable shaft of the motor 4b on which the hovering fan 4a lies horizontally. Therefore, while the toy 1 is floating, no yawing acceleration is produced by the hovering fan 4a, and hence the toy 1 remains directionally stable. 
     When the control switch 5c is shifted to the &#34;HOVER/RUN&#34; position, the motor 3b for the propeller fan 3a is also energized in addition to the motor 4b, so that the propeller fan 3a is also rotated. When the propeller fan 3a is rotated, air is introduced into the cover 1a through the air inlet hole 2h and ejected rearwardly through the air outlet hole 2i, thus propelling the toy 1. The direction in which the toy 1 is propelled is determined by the steering rudder 2j. 
     When the control switch 5c is shifted to the &#34;STOP&#34; position, the motors 3b, 4b are de-energized, and the fans 3a, 4a are stopped. Therefore, the toy 1 is neither hovered nor propelled. If the toy 1 is placed on water, the toy 1 stably floats on the water surface due to the buoyancy of the float 6a. 
     With the air-cushion vehicle toy 1 according to the present invention, when the body 1a is removed from the chassis 1b for battery replacement, motor replacement, or other servicing, the motors 3b, 4b are forcibly de-energized by the power cutoff mechanism 5. Therefore, the motors 3b, 4b are effectively prevented from being energized by mistake during such servicing operation. 
     Since the motor attachment structure 3 is constructed of only the holder frame 3c and the attachment 3d, the number of required parts is small. Because the attachment 3d can easily manually be attached to the holder frame 3c, the motor 3b can easily be installed on the chassis 1b. It is not necessary to use tools such as a screwdriver when the motors are to be replaced for the modification of the toy 1. As a result, the motor attachment structure 3 is low in cost. The attachment 3d is larger than screws and other small-size fastening elements and has a noncircular shape, the attachment 3d is less liable to be lost or roll away when detached from the holder frame 3c. The above advantages hold true for the motor attachment structure 4. In addition, since the casing 4h for the fan 4a is integral with the attachment 4d, the casing 4h can be attached in place at the same time that the motor 4b is installed on the chassis 1b. The motor 4b is therefore also easy to install on the chassis 1b. 
     When the air-cushion vehicle toy 1 is floating, the air pressure in the space 7d is presented from locally leaking out of the space 7d by an air curtain which is established by air ejected from the small holes 7e. Accordingly, the air under pressure which is confined in the space 7d is effective to produce a well-balanced downward air thrust or floating forces. The air-cushion vehicle toy 1 as it floats is thus prevented from being tilted, by a relatively simple construction. 
     The principles of the present invention are also applicable to a remotely controlled air-cushion vehicle toy. 
     Although there has been described what is at present considered to be the preferred embodiment of the present invention, it will be understood that the invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiment is therefore to be considered in all aspects as illustrative, and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description.