Toy with a moving body movable on a platform

A toy includes a platform, a moving body, and a balance bar. The moving body has front and rear wheels rotatable about horizontal rotary axes, a turning wheel, and a drive unit coupled to the turning wheel and one of the rear wheels to drive movement of the moving body when the moving body is disposed on the platform. The turning wheel is rotatable about an axis perpendicular to the rotary axes of the front and rear wheels, and prevents the moving body from falling off the platform when the moving body moves to a peripheral edge of the platform. The balance bar has an intermediate fulcrum portion mounted pivotally on the moving body about a horizontal pivot axis, and two arm portions projecting from two opposite lateral sides of the moving body. Each of the arm portions has a distal section provided with a tray plate adapted for placing game tokens thereon such that a moment of force is applied on the balance bar to cause the balance bar to incline about the pivot axis with respect to the moving body according to the weights of the game tokens and the positions of the game tokens on the tray plates.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a toy with a moving body which is movable on a 
platform and which is provided with a balance bar that can be maintained 
in a balanced state during movement of the moving body by selectively 
placing game tokens on two opposite tray plates of the bar. 
2. Description of the Related Art 
A toy which includes a motor-driven moving body that is movable on a 
platform and that can be prevented from falling off the platform is well 
known in the art. However, there is a constant need to develop new toys of 
the aforesaid type that can entice consumers to purchase the same. 
SUMMARY OF THE INVENTION 
Therefore, the object of the present invention is to provide a toy which 
includes a moving body movable on a platform, and a balance bar which is 
mounted on the moving body and which can be maintained in a balanced state 
by selectively placing game tokens on two opposite tray plates of the bar 
during movement of the moving body on the platform. 
Accordingly, the toy of the present invention includes a platform, a moving 
body, and a balance bar. The platform has a top side and a peripheral 
edge. The moving body has a front end portion provided with a front wheel 
unit which is rotatable about a horizontal first rotary axis, a rear end 
portion provided with a horizontal transmission shaft parallel to the 
first rotary axis, a bottom side provided with a turning wheel between the 
front and rear end portions, and two opposite lateral sides. The 
transmission shaft has two opposite ends. The moving body further has a 
first rear wheel mounted securely on one of the ends of the transmission 
shaft, and a second rear wheel mounted rotatably on the other one of the 
ends of the transmission shaft and rotatable about a second rotary axis 
parallel to the first rotary axis. The turning wheel is rotatable about a 
horizontal third rotary axis generally perpendicular to the first and 
second rotary axes. The turning wheel is entirely disposed higher than the 
lowest vertical point of the front wheel unit and the rear wheels. The 
moving body is provided with a drive unit that is coupled to the turning 
wheel and the transmission shaft to drive movement of the moving body on 
the top side of the platform. The turning wheel contacts the top side of 
the platform after the front wheel unit extends beyond the peripheral 
edge, and enables the front wheel unit to roll completely back on top of 
the platform, thereby preventing the moving body from falling off the 
platform while the drive unit drives movement of the moving body on the 
top side of the platform. The balance bar has an intermediate fulcrum 
portion mounted pivotally on the moving body about a horizontal pivot 
axis, and two arm portions on opposite sides of the fulcrum portion and 
projecting from the lateral sides of the moving body. Each of the arm 
portions has a distal section provided with a tray plate adapted for 
placing game tokens thereon such that a moment of force is applied on the 
balance bar to cause the balance bar to incline about the pivot axis with 
respect to the moving body according to the weights of the game tokens and 
the positions of the game tokens on the tray plates.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 and 2, the preferred embodiment of the toy of the 
present invention is shown to include a platform 1, a moving body 3 
covered by a decorative casing 2, and a balance bar 5 mounted on the 
moving body 3. The moving body 3 is movable on a top side 11 of the 
platform 1, and can be prevented from falling off the platform 1 when the 
moving body 3 moves to a peripheral edge 10 of the platform 1. 
Referring to FIGS. 2 to 4, the moving body 3 has a bottom side provided 
with a pair of front wheels 31 at a front end portion thereof, a pair of 
rear wheels 32 at a rear end portion thereof, and a turning wheel 33 
between the front and rear wheels 31, 32. The turning wheel 33 has a 
bottom portion disposed higher than bottom portions of the front and rear 
wheels 31, 32 such that the turning wheel 33 is normally not in contact 
with the top side 11 of the platform 1 when the moving body 3 is disposed 
on the top side 11. The front wheels 31 are mounted securely on two 
opposite ends of a rotary shaft 49 which is mounted rotatably on the front 
end portion of the moving body 3 such that the front wheels 31 are 
rotatable about a horizontal first rotary axis along the rotary shaft 49. 
Movement of the moving body 3 is driven by a drive unit 4 mounted on the 
moving body 3. The drive unit 4 includes a motor 41 (see FIG. 5), and a 
worm shaft 412 driven by the motor 41 to rotate axially. The worm shaft 
412 engages a drive gear 42 that is mounted on a horizontal shaft 421 in 
the moving body 3. The drive gear 42 engages a gear set 45 which includes 
a plurality of speed-reducing gear members 451 to 455 that are mounted on 
parallel and horizontal first and second transmission shafts 43, 44. The 
second transmission shaft 44 is disposed rearwardly of the first 
transmission shaft 43, and has the rear wheels 32 mounted on two opposite 
ends thereof. Driving energy provided by the motor 41 is transmitted to 
the second transmission shaft 44 via the gear set 45 to cause axial 
rotation of the second transmission shaft 44. A first one of the rear 
wheels 32 is mounted securely on the second transmission shaft 44. A 
second one of the rear wheels 32 is mounted rotatably on the second 
transmission shaft 44. Therefore, the first one of the rear wheels 32 is 
co-rotatable with the second transmission shaft 44 about a second rotary 
axis along the second transmission shaft 44. The gear set 45 further 
includes a gear member 456 which is mounted on the first transmission 
shaft 43 and which engages a gear member 332 that is secured to one end of 
a horizontal rotary shaft 331. The rotary shaft 331 has the turning wheel 
33 mounted securely thereon. The driving force of the drive unit 4 is thus 
transmitted to the turning wheel 33 to cause axial rotation of the turning 
wheel 33 about a horizontal third rotary axis along the rotary shaft 331 
which is perpendicular to the rotary shaft 49 and the second transmission 
shaft 44. When the moving body 3 is normally disposed on the top side 11 
of the platform 1, the turning wheel 33 does not contact the top side 11. 
At this time, the direction of movement of the moving body 3 is not 
affected by the turning wheel 33. However, when the moving body 3 moves to 
the peripheral edge 10 such that the front wheels 31 extend beyond the 
peripheral edge 10, the moving body 3 inclines forwardly and the turning 
wheel 33 contacts the top side 11 of the platform 1. At this time, since 
the turning wheel 33 rotates about the third rotary axis which is 
perpendicular to the first and second rotary axes of the front and rear 
wheels 31, 32, the turning wheel 33 causes the moving body 3 to turn away 
from the peripheral edge 10 and enables the front wheels 31 to climb back 
on the top side 11 of the platform 1. The moving body 3 is thus prevented 
from falling off the platform 1, and is kept on the top side 11 of the 
platform 1. The moving body 3 thus performs straight and turning movements 
on the platform 1. A weight member 34 is provided on a lower portion of 
the moving body 3 so as to lower the weight center of the moving body 3 
and to prevent overturning of the moving body 3 during movement of the 
moving body 3 on the top side 11 of the platform 1. The moving body 3 is 
further mounted with a sound generating member 361 and a control circuit 
36 for controlling activation of the sound generating member 361 such that 
a predetermined sound can be generated. 
Referring again to FIGS. 1 and 2, the balance bar 5 has an intermediate 
fulcrum portion 51 and two arm portions 52 on opposite sides of the 
fulcrum portion 51. The fulcrum portion 51 projects upwardly and 
transversely relative to the arm portions 52, and has an upper end formed 
with a pivot hole 512. The arm portions 52 extend from a lower end of the 
fulcrum portion 51. Each of the arm portions 52 has a distal section 
provided with a tray plate 53 which is adapted for placing game tokens 54 
in the form of small bowls and dishes. The balance bar 5 is mounted on an 
upright mounting portion 37 of the moving body 3 by means of a horizontal 
pivot shaft 55 that is mounted securely on the mounting portion 37 and 
that is perpendicular to the second transmission shaft 44 (see FIG. 3). 
The pivot shaft 55 has a front section 551 projecting from a front side of 
the mounting portion 37, and a rear section 552 projecting from a rear 
side of the mounting portion 37 and extending through the pivot hole 512 
in the fulcrum portion 51 of the balance bar 5 to mount the balance bar 5 
pivotally on the moving body 3. The arm portions 52 project relative to 
the lateral sides of the moving body 3. By placing the game tokens 54 on 
the tray plates 53, a torque, or a moment of force is applied on the 
balance bar 5 to cause the balance bar 5 to incline about the pivot shaft 
55 with respect to the moving body 3 according to the weight of the game 
tokens 54 and the positions of the game tokens 54 on the tray plates 
53.Each of the tray plates 53 has a bottom side provided with a weight 
member 531 to reduce the effect of each of the game tokens 54 on the 
weight ratio when the game tokens 54 are added onto the tray plates 53. 
The decorative casing 2 includes a body casing 6 with front and rear casing 
parts 61, 62, and a head casing 7 with front and rear casing parts 71, 72. 
The front and rear casing parts 61, 62 of the body casing 6 engage one 
another, and cooperatively cover the moving body 3 from front and rear 
sides of the moving body 3. The rear casing part 62 is provided with a 
battery housing 621, which houses a battery set (not shown) for providing 
electrical energy to the motor 41 of the drive unit 4. The front and rear 
casing parts 61, 62 of the body casing 6 cooperatively define two openings 
63 on lateral sides thereof to permit extension of the arm portions 52 of 
the balance bar 5 therethrough. The pivot shaft 55 extends through a 
through hole 622 formed in an upper end portion of the rear casing part 
62. 
The front and rear casing parts 71, 72 of the head casing 7 engage one 
another, and are disposed on top of the body casing 6. The front and rear 
casing parts 71, 72 have main casing portions with confronting inner sides 
which are formed with axially aligned pivot tubes 73 that are sleeved 
rotatably and respectively on the front and rear sections 551, 552 of the 
pivot shaft 55 for mounting the main casing portions of the front and rear 
casing parts 71, 72 rotatably on the upright mounting portion 37 of the 
moving body 3. A pivot plate 711 extends downwardly from a lower end of 
the main casing portion of the front casing part 71, and is formed with a 
pivot hole 712. 
Referring to FIGS. 2, 5 and 6, a swing unit 74 is mounted on the moving 
body 3 to cause leftward and rightward swinging of the head casing 7. The 
swing unit 74 includes an upright and elongated swing plate 75 disposed on 
the front side of the mounting portion 37 of the moving body 3 and below 
the front section 551 of the pivot shaft 55. The swing plate 75 has an 
intermediate portion formed with a pivot tube 751 which is sleeved 
rotatably on a pivot shaft 371 formed on the front side of the mounting 
portion 37 and parallel to the pivot shaft 55. The swing plate 75 further 
has an upper end portion formed with a pivot shaft 752 that projects 
forwardly and that is parallel to the pivot shafts 55, 371, and a lower 
end portion formed with an elongated slot 753. The pivot shaft 752 of the 
swing plate 75 extends rotatably through the pivot hole 712 in the pivot 
plate 711 of the head casing 7. The mounting portion 37 of the moving body 
3 further has an axle 372 which projects forwardly and which extends 
through the elongated slot 753. The swing unit 74 further includes a gear 
wheel 76 which has a back side provided with an eccentric cam wheel 762 
that extends into the elongated slot 753 in the swing plate 75. The axle 
372 extends through an axial hole 761 in the gear wheel 76. Preferably, 
the width measured between lateral edges of the elongated slot 753 is 
generally identical to the diameter of the cam wheel 762. The gear wheel 
76 engages a gear member 77 which is mounted securely on the rotary shaft 
331 of the turning wheel 33 so as to be driven by the drive unit 4 to 
rotate axially. When the gear wheel 76 rotates axially, the eccentric cam 
wheel 762 causes the lower end portion of the swing plate 75 to swing 
leftwardly and rightwardly about the pivot shaft 371, thereby resulting in 
corresponding rightward and leftward swinging of the upper end portion of 
the swing plate 75. Simultaneously, the head casing 7 is caused to swing 
leftwardly and rightwardly about the pivot shaft 55, as shown in FIG. 7. 
Referring back to FIGS. 1 to 3, when the moving body 3 is placed on the top 
side 11 of the platform 1 while the drive unit 4 is actuated, the moving 
body 3 is driven by the drive unit 4 to move on the top side 11 of the 
platform 1 without falling off the platform 1. At the same time, the head 
casing 7 swings leftwardly and rightwardly during movement of the moving 
body 3. Preferably, the top side 11 of the platform 1 is divided into four 
differently patterned regions, such as regions 12 printed with different 
colors. The moving body 3 is designed to pass through the regions 12 in 
sequence. To play a game with the use of the toy of the present 
embodiment, the game tokens 54, which are in the form of bowls and dishes, 
are placed on the tray plates 53 sequentially and respectively by several 
game players during movement of the moving body 3 on the top side 11 of 
the platform 1. The game players take turns in placing a selected one of 
the game tokens 54 on a selected tray plate 53 and at a selected position 
on the selected tray plate 53 in order to maintain balance of the balance 
bar 5. To start with, each of the game players is assigned with a selected 
region 12 on the top side 11 of the platform 1. When the moving body 3 
moves to a certain region 12, the game player who was assigned with that 
region 12 places a selected one of the game token 54 based on the 
aforesaid considerations such that the balance bar 5 is applied with a 
torque. The game player who fails to maintain balance of the balance bar 
5, i.e., who causes the game tokens 54 to fall off the tray plates 53, 
loses the game. 
While the present invention has been described in connection with what is 
considered the most practical and preferred embodiment, it is understood 
that this invention is not limited to the disclosed embodiment but is 
intended to cover various arrangements included within the spirit and 
scope of the broadest interpretation so as to encompass all such 
modifications and equivalent arrangements.