GB2273666A - Toy car. - Google Patents

Abstract

A toy car includes a gear mechanism G1, G2, G3 which drives a front wheel (9b fig. 2) and a rear wheel (10b fig. 2) in a forward direction when a motor 12 rotates in a forward direction and which drives one of a) a right wheel and b) a left wheel in forward direction and the other of the a) right wheel and b) left wheel in a reverse direction when the motor rotates in the reverse direction, to quickly turn the toy car. In a preferred embodiment a radio-controlled toy car is described which includes a controller (2 fig. 1) which transmits a digital control signal, and a toy car (3 fig. 1) which includes a power source, at least one front wheel (9b fig. 2), at least one rear wheel (10b fig. 2), a receiver which receives the transmitted digital control signal controlling the movement of the toy car, and a motor 12 which is rotable in a forward and a reverse direction in accordance with an output signal from the receiver to drive the toy car forward or to make a turn. <IMAGE>

Description

DESCRIPTION "TOY CAR" The present invention relates to a toy car, for example a radio-controlled four-wheel drive toy car capable of making smooth, high-speed turns.

Conventionally, the construction of a radio-controlled toy car enables the driving power of a reversible motor mounted on the toy car to be transmitted to a rear wheel fixed on one end of a rear shaft and to the other rear wheel equipped with a clutch and mounted on the other end of the rear shaft. The radiocontrolled toy car is designed to connect the clutch to drive both rear wheels in the case of forward driving and to disconnect the clutch on turns to free the rear wheel equipped with the clutch and at the same time to drive the other rear wheel in a reverse direction.

However, in the toy car of this type which makes a turn by driving only one rear wheel in a reverse direction with the clutch disconnected, the turn is not precise while the toy car is moving backwards. In this case, the toy car will most likely make an unsmooth turn. Furthermore, since one of the rear wheels is in a free state, the toy car simply cannot make a high-speed turn.

Furthermore, another disadvantage of the two-wheel drive conventional radio-controlled toy is that it is only suitable for playing on a floor. It cannot move on a soft material, such as a carpet or a comforter. Also, in the case of outdoor use, the toy cannot run on a lawn, and cannot obtain driving stability on a surface having even a slight undulation.

According to one preferred aspect of the invention there is provided a radio-controlled toy car including a controller to transmit a control signal and a toy car including a receiver to receive the transmitted control signal for controlling a directional movement of the toy car, a motor driven by a power source to rotate in a forward or reverse direction based on the received control signal, at least one left wheel, at least one right wheel, and a gear mechanism which drives the left wheel and the right wheel to rotate forward when the motor rotates in the forward direction, and which drives one of the left wheel and the right wheel to rotate in reverse when the motor rotates in the reverse direction and the other of the left wheel and the right wheel to rotate forward when the motor rotates in the reverse direction.

According to the radio-controlled toy car of the present invention, when the motor operates in a normal (forward) direction, all of the front and rear wheels turn forwardly, thereby moving the toy car straightforward. On the other hand, when the motor operates in the reverse direction, either both of the left wheels or both of the right wheels turn in the reverse direction, depending on the direction of the turn, while the other set of wheels turn in the opposite, or forward, direction.

The toy car, therefore, turns in the direction of the wheels which are being reversely rotated. Furthermore, due to the fourwheel drive type toy car, the wheels have a high road-gripping power on the whole and can therefore run freely on any surface.

By use of the preferred embodiments of the invention there may be provided: (i) a radio-controleld toy car which can move on any type of surface with high stability; (ii) a radio-controlled toy car which can precisely and smoothly handle a turn; (iii) a radio-controlled toy car which can handle a turn at high-speed.

The invention will now be further described by way of example with reference to the accompanying drawings, in which: FIGURE 1 is a perspective view of the exterior of an embodiment of a radio-controlled toy car according to the present invention.

FIGURE 2 is a bottom view of the toy car according to the present invention.

FIGURE 3 is an exploded perspective view of the tcy car according to the present invention.

FIGURE 4 is a circuit diagram of a controller circuit of the toy car according to the present invention.

FIGURE 5 is an exploded perspective view of a gear mechanism of the toy car according to the present invention.

As shown in FIGURE 1, a preferred embodiment of a radiocontrolled toy car, in accordance with the present invention, is designated generally by the reference character 1. Radiocontrolled toy car 1 includes a controller 2 which transmits a digital control signal, and a toy car 3 which receives the digital control signal and runs in accordance with the received digital control signal. The controller 2 is fitted with a FORWARD button S1 serving also as a CHARGE button, a TURN button S2 serving also as a CHARGE button, a CHARGE lamp LED 5, a TRANSMIT lamp LED 6, and a CHARGE jack 4. As shown in FIGURE 2, under a chassis 5 of the toy car 3 are fitted a CHARGE jack 6 and a POWER switch 7.

In radio-controlled toy car 1, when either one of the FORWARD button S1 of the controller 2 and the TURN button S2 is depressed while lightly pushing together the CHARGE jack 6 under the chassis 5 of the toy car 3 and the CHARGE jack 4 on the controller 2, with the POWER switch 7 under the chassis 5 of the toy car 3 turned off, a battery B (See FIGURE 3) mounted on the toy car 3 will be charged. When battery charge has been completed, the POWER switch 7 under the chassis 5 of the toy car 3 is turned to ON. Then, when the FORWARD button S1 on the controller 2 is depressed, the toy car 3 runs forward. When a light tap is given to the TURN button S2, the toy car 3 turns to the right on the spot. Also, when the TURN button S2 is kept depressed, the toy car 3 starts turning to the right on the spot.

Next, a detailed constitution of the radio-controlled toy car will be explained in the order of the controller 2 and then the toy car 3.

FIGURE 4 shows an internal circuit diagram of the controller 2. The circuit includes a transmission circuit and a charge circuit. First, the transmission circuit will be explained. Q2, Q3, R6, R4, R5, R1, R2, C8 and C7 constitute an astable multivibrator. That is, when the switch S2 is pressed, there is produced a square-wave pulse having an oscillation frequency which is determined by R6, R4 and C7, and by R6, R5 and C8. Also when the switch S1 is pressed, there is produced a square-wave pulse having an oscillation frequency which is determined by R4 and C7, and by R5 and C8. Then, the collector Q3 is connected to the emitter Q1 through R8, for switching Q1.Q1, C1, C2 and L2 make a Hartley oscillator; when this oscillator and the multivibrator are operated for switching, a specific signal will be produced from Q1. That is, a carrier wave produced from Q1 is repetitively outputted at different cycles every time the FORWARD button S1 and the TURN button S2 are alternately depressed. C3, C4 and L1 connected to the output side of Q1 form an antenna matching circuit for matching the antenna ANT with Q1. That is, it functions to cancel the imaginary part (reactance) of impedance of the antenna ANT and Q1, and to send the output of Q1 effectively to the antenna ANT. CS refers to a bypass capacitor; R9 and C5 form a decoupling circuit. Also, in this transmission circuit, when either one of the FORWARD button S1 and the TURN button S2 is depressed, a TRANSMIT lamp D6 comes on to indicate that a signal is being transmitted.

The CHARGE circuit will now be explained. In this CHARGE circuit, when either the FORWARD button S1 or the TURN button S2 is depressed, the voltage (+6V) is differentiated to R15 and C6, and applied to the base of Q4 via D4, instantaneously switching on Q4. Thus the current flows to the base of Q5 via the emitter and base of Q5 and R11, switching on Q5. The emitter current of Q5 flows into a time constant circuit comprising R13, R12 and C9, at the same time becoming the base current of Q4, that is, the base current of Q4 flowing through the emitter of Q5, the collector of Q5, R13, C9, R12, the base of Q4 and the emitter of Q4.The collector current of Q4 forms a current loop flowing for the time of a time constant which is determined by the timeconstant circuit, switching on Q5 for the time of the time constant. At the same time, the emitter current of Q5 flows into the base of Q6 through R14, thereby switching on Q6. Therefore, when the battery B is connected to the CHARGE jack 4 of the controller 2 through the CHARGE jack of the toy car 3, the current of +6V voltage enters Q6 through the battery B, and accordingly the battery B is charged at a high rate for part of the time constant. Even when the TRANSMIT switches S1 and S2 are not depressed, a trickle charge of the battery B is performed through R17.

Then, after the lapse of the time constant, C9 has been almost fully charged. Since, at this time, the base current of Q4 stops flowing, Q4 is not conducted. Simultaneously, the base current of Q5 also stops flowing, Q5 becoming an OFF state; accordingly, Q6 becomes void of the base current caused by the emitter current of Q5. In the meantime, discharge at C9 starts; namely, discharge is effected through the path of C9 (+), R13, R16, D3 and C9 (-) and, at the same time, discharge is done through the path of C9 (+), R14, Q6 (base), Q6 (emitter), D3 and C9 (-), thereby keeping Q6 conducted to continue quick charge.

With the completion of the discharge, the quick charge is finished. Therefor, battery charge is performed for a total period of charge time and discharge time of C9. The CHARGE lamp D5 is lit only for the charge time of C9.

Next, the toy car 3 will be explained. Toy car 3, as shown in FIGURES 2 and 3, include the chassis 5, and a body 8 mounted on the chassis 5. The chassis 5 is fitted with front wheels 9a and 9b and rear wheels i0a and lOb and is mounted, as shown in FIGURE 2, with a chargeable battery (e.g., a nickel-cadmium storage battery) B, a reversible motor 12 operated by power from this battery B, and a gear mechanism G (see FIGURE 5) which transmits the torque of this motor 12 to drive the rear wheels i0a and lOb and the front wheels 9a and 9b. The chassis 5 is mounted with a receiver on a base 30 for controlling the motor 12 in accordance with a digital control signal received from the controller 2.

The wheels 9a, 9b, 10a and 10b are constructed by installing a rubber band around each wheel. Of the wheels 9a, 9b, lOa, and lob, the right front wheel 9b is fixedly mounted on a front shaft 9, and the right rear wheel lOb, on a rear shaft 10 (see FIGURE 5). The left front wheel 9a is mounted on the front shaft 9 in such a manner that it can idle, and the left rear wheel lOa, on the rear shaft 10 in the same manner. These wheels 9a, 9b, i0a and lOb are designed to be driven by the torque of the motor 12 through the gear mechanism G.

The gear mechanism G, as shown in FIGURE 5, basically includes a gear mechanism G1 for driving the right wheels and a gear mechanism G2 for driving the left wheels. In the gear mechanism G2 for driving the left wheels is incorporated a change gear mechanism G3.

The gear mechanism G1 for driving the right wheels comprises a gear 12a mounted on the shaft of the motor 12, gears 32a, 32b, 32c, 32d, 32e and 32f arranged in the left rear part of the chassis 5, and gears 32g, 32h, 32i, 32j, 32k and 321 arranged in the right part of the chassis 5. The torque of the motor 12 is transmitted to the gear 32f through the gears 12a, 32a, 32b, 32c, 32d and 32e. Since gear 32f is fixed on the rear shaft 10, the torque transmitted to the gear 32f is immediately transmitted to the rear shaft 10, and the right rear wheel lOb fixed on this rear shaft 10 rotates normally and reversely in accordance with the direction of rotation of the motor 12.Also, the torque transmitted to the rear shaft 10 is transmitted to the gear 32g fixed on the rear shaft 10, and the torque of this gear 32g is transmitted to the final gear 321 through the gears 32h, 32i, 32j and 32k. The final gear 321 is fixed on the front shaft 9.

Therefore, the torque transmitted to the gear 321 is immediately transmitted to the front shaft 9. As a result, the right front wheel 9b fixed on front shaft 9 rotates normally and reversely in accordance with the direction of rotation of the motor 12.

Furthermore, the direction of rotation of right front wheel 9b is the same as the direction of rotation of the right rear wheel lOb.

The gear mechanism G2 for driving the left wheels include the gear 12a mounted on the motor shaft, and gears 32a, 32b, 32c, 33a, 33b, 33c, 33d, 33e, 33f, 33g, 33h, 33i and 33j are arranged in the left-hand part of the chassis 5. The torque of the motor 12 is transmitted to the gear 33e through the path composed of either the gears 12a, 32a, 32b, 32c, 33a, 33b, 33c and 33d or the gears 12a, 32a, 32b, 32c, 33a, 33c and 33d. That is, in gear mechanism G2 for driving the left wheels, the gear 33a serves as a planetary gear, which is so constructed as to be able to revolve on the center of the axis of the gear (sun gear) 32c by the action of the arm 34. This planetary gear 33a is designed to selectively mesh two gears 33b and 33c located after the planetary gear 33a in accordance with the direction of rotation of the motor 12. That is, the planetary gear 33a constitutes the change gear mechanism G3, moving into mesh with the gear 33b when the motor 12 turns normally and with the gear 33c when the motor 12 turns reversely.

Therefore, the left rear wheel 10a installed on the rear shaft 10 such that it can rotate idle is turned forwardly by the torque transmitted to the gear 33e regardless of the path of transmission of the torque. Furthermore, the torque of gear 33e is transmitted to the final gear 33j through the gears 33f, 33g, 33h and 33i. The left front wheel 9a mounted on the front shaft 9, such that it can idle, is also turned forwardly by the torque thus transmitted to the final gear 33j irrespective of the path of the torque.

Between the wheel-driving gear mechanism G1 and G2 is interposed a clutch C. That is, of the mating faces of the gears 32i and 32j, and the gears 33g and 33h which are coaxially mounted, the mating faces of the gears 32i and 33g have an angle projection, while the mating faces of the gears 32j and 33h are provided with a V-groove in which the angle projection stated above can fit. These angle projections and V-grooves are engaged by means of a spring SP. Accordingly, even if the front or rear wheels are forced to turn while holding the other wheels by hand, it is possible to prevent damaging the wheel-driving gear mechanisms G1 and G2.The location of this clutch C is not limited to the location stated in the present embodiment; the clutch C may be positioned in any place where damage to the wheel-driving gear mechanisms G1 and G2 can be prevented.

The gears 32a, 32b, 32c, 32d, 32e and 32f, constituting the gear mechanism G1 for driving the right wheels, are assembled in a left center frame 5a, see also FIGURE 2, installed at the left rear part of the chassis 5. The gears 32g, 32h, 32i, 32j, 32k and 321, also constituting gear mechanism G1 for driving the right wheels, are assembled within a right outer frame 5c, see also FIGURE 2, installed in the right-side part of the chassis 5.

Furthermore, the gears 33a, 33b, 33c, 33d, 33e, 33f, 33g, 33h, 33i and 33j, constituting the gear mechanism G2 for driving the left wheels, are assembled within a left outer frame 5b mounted in the left-side part of the chassis 5.

The gear mechanism G of the above-described constitution has the following functions. When the motor 12 is turning normally (i.e., in the forward direction), the gear mechanism G1 for driving the right wheels rotates the right wheels 9b and lOb forward. Also, the gear mechanism G2 for driving the left wheels rotates the left rear wheels 9a and 10a forward because the arm 34 swings to move the planetary gear 33a into mesh with the gear 33b. That is, when the motor 12 is normally turning, all of the wheels 9a, 9b, iCa and lOb rotate forwardly. Therefore, the toy car 3 moves forwards.

On the other hand, when the motor 12 turns in the reverse direction, the gear mechanism G1 for driving the right wheels rotates the right wheels 9b and lOb backwards. The gear mechanism G2 for driving the left wheels, however, rotates the left wheels 9a and i0a forward as the arm 34 swings to move the planetary gear 33a into mesh with the gear 33c. That is, with the motor 12 turning reversely, the right wheels 9b and lOb rotate backwards, while the left rear wheels 9a and 10a rotate forward, thus turning the toy car 3 to the right. Of course, to turn the car left, the same principle applies to rotate the right wheels forward and the left wheels backwards.

According to the radio-controlled toy car 1 of the abovedescribed constitution, the following advantages are obtainable.

That is, according to the radio-controlled toy car 1 of the preferred embodiment, the right wheels 9a and lOb rotate backwards, while the left wheels 9a and 10a rotate forwardly so that the toy car 1 can make a quick right turn on the spot.

Furthermore, the toy car 1, being a four-wheel drive toy car, has wheels having a high road-gripping power on the whole, therefore being able to drive freely at any place.

According to the present invention described above, the radio-control toy car has a controller for transmitting a digital control signal, and a toy car mounted with a battery, a receiver for receiving the digital control signal, and a motor capable of normal and reverse revolutions in accordance with an output signal from the receiver to drive forwardly and turn around the car in accordance with the normal and reverse revolutions of the motor. The toy car is provided with a gear mechanism incorporated for forwardly driving all of the front and rear wheels when the motor is running in the normal condition. The gear mechanism includes a change gear mechanism for forwardly driving either right or left wheels while reversely driving the other wheels when the motor is running in the reverse direction.

Therefore the user can easily enjoy radio control of the toy car, which makes quick turns on the spot, on all types of surfaces.

Although a preferred embodiment of the invention has been shown and described, it will be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and the spirit of the invention, the scope of which is defined in the appended claims.

Claims (12)

CLAIMS:

1. A toy car comprising: a motor. to be driven by a power source, to rotate in a forward or reverse direction; at least one left wheel; at least one right wheel; and a gear mechanism which drives said left wheel and said right wheel to rotate forward when said motor rotates in said forward direction, and which drives one of said left wheel and said right wheel to rotate in reverse when said motor rotates in said reverse direction and the other of said left wheel and said right wheel to rotate forward when said motor rotates in said reverse direction.

2. A toy car as claimed in claim 1, wherein said gear mechanism includes a gear change mechanism which drives the other of said left wheel and said right wheel to rotate forward when said motor rotates in either said forward or reverse direction.

3. A toy car as claimed in claim 1 or 2 which is radio controlled and additionally comprises: a controller to transmit a control signal; and the toy car including a receiver to receive said transmitted control signal for controlling a directional movement of said toy car; and said motor being activated to rotate in a forward or reverse direction based on said received control signal.

4. A radio-controlled toy car including a controller, which transmits a digital control signal, and a toy car including a power source, a left front wheel, a right front wheel, a left rear wheel, a right rear wheel, a receiver which receives said transmitted digital control signal from said controller, said digital control signal controlling a movement of said toy car, and a motor rotatable in a forward and a reverse direction in accordance with an output signal from said receiver to drive said toy car forward or to make a turn, said toy car in said radiocontrolled toy car further comprising:: a gear mechanism which drives said front left and right wheels and said rear left and right wheels in a forward direction when said motor rotates in said forward direction, and which drives one of a) said front right wheel and said rear right wheel and said b) said front left wheel and said rear left wheel in a forward direction and the other of a) said front right wheel and said rear right wheel and said b) said front left wheel and said rear left wheel in a reverse direction when said motor rotates in said reverse direction to turn said toy car.

5. A radio-controlled toy car as claimed in claim 4, wherein said gear mechanism includes: a first gear mechanism which drives one of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel; and a second gear mechanism which drives the other of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel, said first gear mechanism driving said one of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel in a forward direction when said motor rotates in said forward direction and said second gear mechanism driving said other of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel in a forward direction when said motor rotates in said forward direction.

6. A radio-controlled toy car as claimed in claim 5, wherein said second gear mechanism includes a gear change mechanism which drives the other of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel in said forward direction when said motor rotates in either said forward or reverse direction, while said first gear mechanism drives said one of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel in said reverse direction when said motor rotates in said reverse direction.

7. A radio-controlled toy car as claimed in claim ci, wherein said gear change mechanism includes: a sun gear connected between said motor and one of said rear wheels, said sun gear rotating in the same direction as said motor; a planetary gear connected between said sun gear and said one rear wheel, said planetary gear being revolvable on a center of an axis of said sun gear and said planetary gear including a swinging arm which moves said planetary gear into mesh with a selected gear; a first gear located between said planetary gear and said one rear wheel; and a second gear located between said planetary gear and said one rear wheel, said planetary gear selectively meshing with said first gear, said first gear thereby rotating in a direction opposite from that of said sun gear, to rotate the other of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel in said forward direction when said motor rotates in said forward direction, and selectively meshing with said second gear, said second gear thereby rotating in a direction opposite from that of said sun gear, to rotate the other of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel in said forward direction when said motor rotates in said reverse direction.

8. A radio-controlled toy car as claimed in claim 6 or 7, wherein when said motor rotates in said reverse direction, said front right wheel and said rear right wheel rotate in a reverse direction and said front left wheel and said rear left wheel rotate in a forward direction, so that said toy car makes a right turn.

9 s-. A radio-controlled toy car as claimed in any one of claims 4 to 8, wherein said toy car is a four wheel drive controlled toy car.

10. A toy-car substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Amendments to the claims have been filed as follows

11. A toy car comprising: a motor driven by a power source to rotate in a forward or reverse direction; at least one left wheel; at least one right wheel; a gear mechanism which drives said left wheel and said right wheel to rotate forward when said motor rotates in said forward direction, and which drives one of said left wheel and said right wheel to rotate in reverse when said motor rotates in said reverse direction and the other of said left wheel and said right wheel to rotate forward when said motor rotates in said reverse direction, said gear mechanism including: : a first gear mechanism which drives said one of said left wheel and said right wheel in a forward direction when said motor rotates in said forward direction, and drives said one of said left wheel and said right wheel in a reverse direction when said motor rotates in said reverse direction; a second gear mechanism including a gear change mechanism which drives the other of said left wheel and said right wheel in said forward direction when said motor rotates in either said forward or reverse direction; and said gear change mechanism including: a sun gear connected between said motor and said one of said left and right wheels, said sun gear rotating in the same direction as said motor; a planetary gear connected between said sun gear and said one wheel, said planetary gear being revolvable on a center of an axis of said sun gear and said planetary gear including a swinging arm which moves said planetary gear into mesh with a selected gear; a first gear located between said planetary gear and said one wheel; and a second gear located between said planetary gear and said one wheel; said planetary gear selectively meshing with said first gear, said first gear thereby rotating in a direction opposite from that of said sun gear, to rotate the other of said left wheel and said right wheel in said forward direction when said motor rotates in said forward direction, and selectively meshing with said second gear, said second gear thereby rotating in a direction opposite from that of said sun gear, to rotate the other of said left wheel and said right wheel in said forward direction when said motor rotates in said reverse direction.

12. A radio-controlled toy car including a controller, which transmits a digital control signal, and a toy car including a power source, a left front wheel, a right front wheel, a left rear wheel, a right rear wheel, a receiver which receives said transmitted digital control signal from said controller, said digital control signal controlling a movement of said toy car, and a motor rotatable in a forward and a reverse direction in accordance with an output signal from said receiver to drive said toy car forward or to make a turn, said toy car in said radio-controlled toy car further comprising:: a gear mechanism which drives said front left and right wheels and said rear left and right wheels in a forward direction when said motor rotates in said forward direction, and which drives one of a) said front right wheel and said rear right wheel and said b) said front left wheel and said rear left wheel in a forward direction and the other of a) said front right wheel and said rear right wheel and said b) said front left wheel and said rear left wheel in a reverse direction when said motor rotates in said reverse direction to turn said toy car; said gear mechanism including:: a first gear mechanism which drives said one of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel in a forward direction when said motor rotates in said forward direction, and drives said one of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel in a reverse direction when said motor rotates in said reverse direction; a second gear mechanism including a gear change mechanism which drives the other of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel in said forward direction when said motor rotates in either said forward or reverse direction; and said gear change mechanism including: a sun gear connected between said motor and one of said rear wheels, said sun gear rotating in the same direction as said motor; a planetary gear connected between said sun gear and said one rear wheel, said planetary gear being revolvable on a center of an axis of said sun gear and said planetary gear including a swinging arm which moves said planetary gear into mesh with a selected gear; a first gear located between said planetary gear and said one rear wheel; and a second gear located between said planetary gear and said one rear wheel, said planetary gear selectively meshing with said first gear, said first gear thereby rotating in a direction opposite from that of said sun gear, to rotate the other of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel in said forward direction when said motor rotates in said forward direction, and selectively meshing with said second gear, said second gear thereby rotating in a direction opposite from that of said sun gear, to rotate the other of said a) front right wheel and rear right wheel and said b) left front wheel and left rear wheel in said forward direction when said motor rotates in said reverse direction.