Note: Descriptions are shown in the official language in which they were submitted.
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MINIATURE TOY VEHICLE ASSEMBLY
BACKGROUND OF THE INVENTION
The present invention relates to a miniature toy
vehicle assembly. As an e~ample of the size of toy
vehicle assembly to which the invention is applicable it
may comprise a vehicle housing molded of a plastic resin
having an overall length of about 5 cm, and a motor
assembly having a spring-powered prime mover mounted on
the vehicle housing, and which has an overall weight of
about lOg.
Since such a miniature toy car has a large spring
power when compared with the overall weight, the car can
be propelled over a long distance at high speed.
~oreover, by making the best use of its larger power, it
is possible for a child to enjoy a wide variety of games
with the car. For example, if the car is made to collide
with an obstacle, its course will be changed to an
unexpected direction by means of the reaction force of the
collision, or the car can be jumped by means of a jump.
Such a course change by means of the reaction force
of a collision is remarkably effected by the fact that the
car body rebounds from the obstacle by the reaction
applied thereto and the front wheels thereof are lifted
slightly off the support surface,
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i.e., the ground. In other words, it is considered
that the course change is caused by a reduction in
the lateral resistance due to the lift-off of the
front wheels, the unbalance between the right and
left rear wheels, the lateral component of the
reaction force produced by the collision, and so
forth. Accordingly, if the car is smaller in overall
length, is more compact and lightweight, and has a
eonstruction that allows the ront wheels to lift
off more easily, it is possible to enjoy a toy vehiele
with a more varied change of course.
On the other hand, the fact that the car is
lightweight and compact is a disadvantage when
enjoying the amusing running of the car, so much so
that the interest of the play is redueed, since when
the ear is made to collide against an obstacle so
that its course is changed to an unexpeeted direetion
by means of the reaction force as a result of the
collision, the car may undesirably be made to roll
over by the reaction force alone, or since the car
eannot land stably after a jump and moreover the
ear ean easily roll over even during normal running
when it only slightly touches something, or it
encounters unevenness in the support surface while
` 25 running.
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Accordingly, the toy industry demands a continued
infusion of new toy concepts and is still receptive
to new and novel toy vehicle designs to entertain
and elicit the interest of children.
SU~MARY OF THE INVENTION:
The present invention provides a miniature toy
vehicle assembly that comprises a plastic resin housing
member including an upper body shell and a lower frame
member, a front wheel assembly attached to the housing
1~ member and including a front axle and a pair of front
wheels, a rear wheel assembly attached to the housing
member and including a rear axle and a pair of rear
wheels, and a motor assembly attached to the housing
member and having a spring-powered prime mover driving
the rear axle of the rear wheel assembly.
The motor assembly according to the invention
is attached to a substantially central part of the
upper surface of the lower frame member. The ratio (~/L)
of the length (~) of the motor assembly to the length
(L) of the lower frame member is about 0.5.
The front axle is rotatably supported in the
vicinity of the longitudinal front end of the motor
assembly. The distance between the front axle and
the rear axle is within the range of the length [~)
of the motor assembly.
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.
The front axle and the rear axle are attache~ to the
housing member so that when the miniature toy vehicle assembly
is placed on a flat support surface, the plane including ~he
front axle and the rear axle will intersect the flat support
surface in front of the front axle at a predetermined angle (~).
~ he relationship between the total weight (w) of the
front wheel assembly, the rear wheel assembly, and the motor
assembly, and the overall weight (W) of the miniature toy
vehicle assembly is: w/W ~ 0.5.
Also in accordance with the present invention there is
provided a miniature toy vehicle assembly capable of self
propulsion across a support surface and having the ability to
travel at relatively high speeds in a stable manner consisting
of:
a lightweight plastic resin housing assembly including
an upper body member and a lower frame member of approximately
50 mm in length;
a front wheel assembly operatively attached to the
lower frame member including a pair of front wheels;
a rear wheel assembly operatively attached to the lower
frame member includiny a pair of rear wheels o~ a diameter
greater than the diameter of the front wheels of the front wheel
assembly; and
a motor assembly operatively attached to one of the
front and rear wheel assemblies, the ratio of the length of the
housing assembly to the length of the motor assembly being
approximately equal to the ratio of the total weight of the
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0388
front wheel assembly, of the rear wheel assembly and the motor
assembly to the overall weight of the toy assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described,
with reference to the accompanying drawings, wherein:-
Figure 1 is a front elevation of a miniature toyvehicle assembly in accordance with a preferred embodiment of
the present invention;
Figure 2 is a side elevation of the miniature toy
vehicle assembly of Fig. l;
Figure 3 is a sectioned side elevation of
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the vehicle housing of the miniature toy vehicle
assembly of Fig. l;
Figure 4 is a plan view of the miniature toy
vehicle assembly of Fig. 1, with the upper body shell
thereof removed;
Figure 5 is a side elevation of the miniature toy
vehicle assembly of Fig. 1 with the body and wheels
thereof removed;
Figure 6~is an exploded perspective view of an
example of a motor assembly of the miniature toy
vehicle assembly of Fig. l;
Figure 7 is a side elevation of the miniature
toy vehicle assembly of Fig. 1 with the body and the
wheels thereof removed, illustrating the way in
which the front wheels thereof lift off; and
Figure 8 is a front elevation of an airplane to
which the present invention is applied.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
The following description is provided to enable
any person skilled in the toy industry to make and
use the present invention and sets forth the best modes
contemplated by the inventor for carrying out his
invention. Various modifications, however, will remain
readily apparent to those skilled in the art, since
the generic principles of the present invention have
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been defined herein speciflcally to provide a novel
miniature toy vehicle assembly.
A primary object of the present invention is the
provision of a miniature toy vehicle assembly having
a highly stable running performance desplte its
compact and lightweight structure, which is easily
capable of performing a jump, course change and the
like as well as being able to move stably in -these
various manoeuve,rs as well as in normal running,
by~in particular, enabling the front wheels thereof
to be lifted off the support surface and returned
thereto.
Referring now to Figs. 1 thru 4 of the drawings,
a toy vehicle assembly in accordance with a preferred
embodiment of the present invention shown in these
figures comprises a vehicle housing 1 constituted by
an upper body shell 2 and a lower frame member 3, a
self-contained motor assembly mounted on the vehicle
housing 1, a front axle 5 and a rear axle 6 attached
to the lower frame member 3 and the motor assembly 4,
respectively, and front wheels 7 and rear wheels 8
attached to the front axle 5 and the rear axle 6,
respectively. The toy vehicle assembly in accordance
with the embodiment has an total weight of 10.5g.
The vehicle housing 1 is made of a plastic resin,
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has an overall length of about 50 mm, a width of about
30 mm and a height of 30 mm. The weight of the upper
body shell 2 is 3g and that of the lower frame member
is 1.5g, totalling 4.5g. The upper body shell 2
~ 5 and the lower frame member 3 are screwed to each
: other by means of a screw 24.
The upper body shell 2 is designed so that the
external appearance thereof simulates a real racing
carO In this embodiment, a roof 21 is provided with
a sunroof 22, and each of window portions is fitted
with a window member 23 made of a plastic resin to
look like window glass.
The lower frame member 3, having a substantially
L-shaped cross sectional configuration, is formed
so that the self-contained motor assembly 4, described
later r can be mounted onto the central part of its
base surface 30. The lower frame member 3 has a
retaining tab 31 and a retaining hook 32 provided to
the rear and front of the self-contained motor as-
sembly 4, respectively. Moreover, as shown in Fig. 5,
a bearing 33 rotatably supporting -the front axle 5
is provided in the vicinity of the retaining hook 32,
and a notch 34 is provided slightly behind the central
part of the lower frame member 3, corresponding to the
rear axle 6. A bumper 35 is provided at the front end
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of the lower frame member 3, while a bracket 36 is
provided at the rear end, projecting upward and
acting as a number plate. The bracket 36 is arranged
so as to face a vertical member 25 (in this embodi-
ment, a vertical piece 25 is provided) provided atthe rear end of the upper body shell 2 with a pre-
determined distance therebetween so that a weighted
member such as a coin of monetary value, e.g., a
;~ penny or nickel, can be clamped between the bracket
36 and the vertical member 25.
A guide member or portion 13 forms a curvilinear
surface at the bottom of the bracket 36. The guide
member 13 is configured to contact and slide on a
support surface 100 (Figs. 5 and 7) when the front
wheels 7 are lifted off the support surface 100.
The guide member 13 is positioned to support the
miniature toy vehicle when it rotates about the rear
axle 6. Accordingly, the toy, when propelled forward,
provides an impression of high speed acceleration
with its front wheel assembly being lifted off the
support surface 100 as a result of the weight of the
weighted member.
The motor assembly 4 is formed by providing a
spring 42 and a gear train 43 for transmitting power
in a motor housing 41. Referring now to Fig. 6,
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showing an example of the motor assembly 4, the motor
housing 41 comprises side shells 411, 412 and an
intermediate plate 413 clamped therebetween and is
made of a plastic resin. The motor housing 41 accomo-
dates the spring 42 and the gear train 43. The gear
train 43 has a winding system, i.e., a system for
storing energy in the spring 42, and a driving system,
i.e., a system for driving an output shaft, thereby
allowing power 'to be reciprocally transmitted between
the spring 42 and the rear axle 6. The gear train 43
is formed so that it is lightweight by employing a
plastic resin with a modulus of, for example, 0.3.
,~ The thus formed motor assembly 4 of this embodiment isconstructed so as to have a weight of about 3g, ex-
clusive of the rear axle 6.
The winding system of the gear train 43 i.e.,
the system for storing energy in the spring 42, com-
prises a pinion 431 secured to the rear axle 6 attached
to the housing 41, a first spur gear 432 constantly
engaging the pinion 431, a winding pinion 433 engaging
the spur gear 432, and a small gear wheel 434 secured
to a sprins shaft 421 and engaging the pinion 433.
The numbers of teeth of these gears are, for example,
10, 18, 10 and 18, respectively, in the en~agement order.
The winding pinion 433 is movable born so that it en-
gages the spur gear 432 only during the winding-up.
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03E38
The driving system, i.e., the system for driving
an output shaft, comprises a large gear wheel 435
secured to the spring shaft 421, a driving pinion
436 engaging the large gear wheel 435, a second
S spur gear 437 provided integrally with the pinion
~` 436 and engaging a pinion 438 provided integrally
with the first spur gear 432. The numbers of teeth
of these gear wheels are, for example, 42, 9, 21 and
8, respectively, in the engagement order. The driv-
ing pinion 436 is movably born so as to engage with
the large gear wheel 435 only during the driving of
the toy car. It must be noted that the above first spur
gear 432 and the pinion 431 function as gears in the
driving system.
The speed ratio of the rear axle 6 to the spring
shaft 421 of the above gear train 43 is 1.8 for the
winding system and 22.05 for the driving system.
Therefore, a 1.8 revolution of the rear axle 6 winds
the spring 42 one revolution, while unwinding the
spring 42 one revolution rotates the rear axle 6
to be rotated 22.05 times. Accordingly, a suffi-
ciently large power can be stored by a short retreat
distance, and high-speed long-distance running is
made possible by releasing the power little by little.
The ratio fjL of length ~ of the motor assembly 4
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to the length L of the lower frame member 3 is set
to be about 0.5. In this embodiment, L is 48mm, and
I is 25mm, and hence ~/L is 0.52. The motor assembly
4 is mounted in the center of the bottom surface 30
of the lower frame member 3 and is secured by engaging
a retaining projection 414 formed at the rear end of
the motor housing 41, with the retaining tab 31,
as well as engaging a step 415 formed at the front
end of the motor housing 41 by the retaining hook 32.
The front axle 5 has the front wheels 7 attached
to the right and left ends thereof, and is supported
horizontally by the bearing 33 of the lower frame
member 3 before the motor assembly 4 is mounted.
The motor assembly 4 is then attached, covering the
front axle 5 with the fxont end of the motor housing
41, so that the front axle 5 is indirectly rotatably
; supported by the motor assembly 4. Needless to say,
however, the front axle 5 could be attached directly
to the motor housing 41 of the motor assembly 4, or
the front axle 5 could be attached directly to the
lower frame member 3. The distance between the front
wheels 7 attached to the front axle 5 is about 24mm
in this embodiment.
The rear axle 6, as described above, has the
pinion 439 secured to the central part thereof and
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is attached so that it is supported horizontally by
the motor housing 41, and it has the rear wheels 8
attached to both ends thereof. Accordingly, the rear
axle 6 is directly and rotatably supported by the
motor assembly 4 and is attached to the lower frame
member 3 together with the motor assembly 4. It must
be noted that the distance between the rear wheels 8
attached to the rear axle 6 is about 24mm in this
embodiment.
The distance between the front axle 5 and the
rear axle 6 is set to be within the range of the
length ~ of the motor assembly 4. In this embodiment,
the distance between the two axles is 20mm, which is
less than ~ (25mm). Accordingly, the driving system
comprising the front and rear axles 5, 6 with the wheels
7, 8 and the motor assembly 4 is mounted so as to be
concentrated at a substantially central portion of
the lower frame member 3.
The weight w of the driving system is set so
that the ratio of the weight w to the overall weight W
of the car body including the driving system will be
larger than 0.5, i.e., w/W > 0.5. In the embodiment,
the weight w of the driving system is about 6g, which
is the sum of the total weight, 1.2g, of the front
wheels 7 and the front axle 5, the total weight,
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l.9g, of the reax wheels 8 and the rear axle 6, and
the weight, 3g, of the motor assembly 4. On the other
hand, the overall weight W of the car body is about
10.5g, which is the sum of the above 6g and the weight,
4.5g, of the -~ehicle housing 1. Accordingly, the
ratio, w/W, is 0.57, satisfying the above condition.
The front axle 5 and the rear axle 6 are attached
to the housing member 1 so that when the miniature
toy car is placed on a flat support surface 100,
the plane K including the front axle 5 and the rear
axle 6 will intersect the flat support surface 100
in front of the front axle 5 at a predetermined angle
(0), as shown in Fig. 5. In other words, the height
relationship between the mounting positions of the
front axle 5 and the rear axle 6 is set so that the
`, straight line K connecting the front axle 5 and the
; rear axle 6 intersects the flat support surface 100
in front of the front axle 5 at an angle ~. Therefore,
the rear axle 6 is attached at a position further
from the surface 100 than is the front axle 5. On
the other hand, the bottom surface 30 of the lower
frame member 3 is maintained substantially parallel
to the support surface 100. In consequence, the
rear wheels 8 used have a larger diameter than the
front wheels 7. In this embodiment, the diameters of
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the front wheels 7 and the rear wheels 8 are llmm and
: 14mm, respectively.
The angle ~ i5 represented by:
d sin 9 = 2 (a2 - a
3 = sin~l ( 2 al)
where d is the distance between the front axle 5
and the rear axle 6; al the diameter of the front wheels
7; and a2 the diameter of the rear wheels 8.
If the following numerical values are substituted
for d, a2 and a1 in the above formula to obtain ~,
i.e., d = 20mm, a2 = 14mm and al = llmm, the angle ~
is determined to be about 4 degrees in this embodiment.
The operation of the miniature toy car assembly
in accordance with the embodiment described above will
now be e~plained.
To propel the miniature toy car assembly in ac-
cordance with the embodiment, the upper body shell 2
is first held with the fingers, and the car body is
pushed backward in such a manner that the r~ar wheels
8 are rubbed against the support surface thereby
storing energy in the spring 42 of the motor assembly
~ 4. Removing the hand from the upper hody shell 2 allows
`~ the rear wheels 8 to be driven by means of the power
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from the spring 42, so that the car body is propelled
forward. If the car body is allowed to run as it isl
the car body travels in a straight line at high speed.
It is also possible to play with the car by changing
the course of the car body by means of a reaction
force produced by making the car body collide against
a suitable obstacle. Furthermore, it is possible to
jump the car body by making it run over a jump.
In such various ways of running, the miniature
toy car assembly of the invention is able to run
stably due to the fact that the center of gravity
thereof is at the central part of the car body. This
is because the driving system comprising the front and
rear axles 5 r 6 with the wheels 7, 8, and the motor
assembly 4 is concentrated at a substantially central
part of the lower frame member 3 by making the length
of the motor assembly 4 about 1/2 of the overall length
L of the lower frame member 3, and by mounting the motor
assembly 4 in the central part of the lower frame mem-
ber 3 as well as attaching the front axle 5 and therear axle 6 within the range of the length of the
motor assembly 4, and because the weight w of the
driving system is made to be not less than 1/2 of the
overall weight W of the car body. In addition, since
the fact that the distance between the front and rear
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axles is small, as mentioned above, means that the
turning moment about the rear wheels is small, the
car body is able to turn quickly, thereby increasing
the course-change effect.
Moreover, in the present invention, the rear
axle 6 is attached at a position higher than the
front axle 5 so that the plane including the two
axles, i.e., the straight line K connecting the axles,
is inclined down toward the front and intersects
the support surface 100 at the angle 6. The moment N
of the force making the front wheels 7 contact the
support surface 100 is:
N = Fd sin ~ (~ = 2 + ~)
= Fd cos ~
where d is the distance between the rear axle 6
and the front axle 5; and F is the force applied
about the rear axle 6 as a fulcrum. Since the straight
line IC inclines forward, the angle ~ decreases as
the front wheels 7 lift off, and becomes zero when the
straight line K is parallel to the support surface 100.
If the angle 0 is within this range, the action that
causes the front wheels 7 to be lifted off is at a
maximum when they are on the support surface 100 and
decreases with the lift-off thereof. Consequently,
~ 25 the action that makes the front wheels 7 contact the
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support surface 100 increases in accordance with the
lift-off thereof and becomes a maximum when the angle
~ is zero, functioning as a force restraining the
lifting-off action.
These actions permit the miniature toy car
assembly of the present invention to displa~ the
following features. Namely, when the toy car collides
with an obstacle, the front end thereof easily lifts
off, the car ca~ readily effect a rapid turn, and
then the front end drops easily. Accordingly, even
if the car is made to collide at a relatively low
speed, it is possible to change the course the~eof
to an unexpected direction. On the other hand, in
a collision at high speed, since the front wheels
are rapidly brought into contact with the support
surface, there is no possibility of the lateral rolling
of the car, so that it is possible to enjoy watching
the car turn rapidly to a different direction. In
this embodiment, the distance between the right and
left wheels attached to each of the front and rear axles
is made to be larger than the distance between the
axles. This, in cooperation with the above actions,
facilitates the turning of the toy vehicle as well as
increasing the running stability.
The above action that lifts the front wheels off
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the support surface at a collision is mainly caused
by the reaction force as a result of the collision and
the rotational reaction force of the spring.
On the other hand, the action that brings the front
wheels into contact with the support surface is
principally caused by gravity applied to the front
wheels. In the present invention, these actions
function synergically, since at least half of the
overall weight is placed at the center of the lower
frame member, as described above.
It must be noted that if the inclination of
the center line on the side of the upper body shell
is made larger than the above angle 9 as is in this
embodiment, the rolling of the car body can be sup-
pressed more effectively. Moreover, when the car
body is moved backward in order to store energy in
the spring, the fingers can more easily grasp the
upper body shell, so that even infants can readily
operate the toy vehicle.
hs has been described, according to the present
invention it is possible to propel a toy vehicle
highly stably although it is compact and lightweight.
Moreover, when the car collides against an obstacle,
the car will not easily roll laterally. On the con-
trary, such a collision will use its reaction to
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increase the course change ef~ect favorably. According-
ly, the present invention allows children to enjoy a
wide veriety of car-propelling games in addition to
normal play with the toy vehicle.
Persons skilled in the toy field would be capable
of modifying the various embodiments of the present
invention within its generic teachings. In particu-
lar, in the above embodiment, the upper body shell of
the housing member has a configuration which simulates
a racing car. However, it ~ill be readily understood
that the upper body shell could have a configuration
which simulates a airplane as shown in Fig. 8 or
anv other desired configuration. Since in such a case
the constructions of the parts other than the upper
body shell can be the same as those in the above em
bodiment, any detailed description thereof is un-
necessary.
It will thus be seen that the objects set forth
above, among those other objects made apparen~ from
the preceding description, are efficiently attained
and, since certain changes may be made in the above
constructions without departing from the spirit and
scope of the invention, it is intended that all
matters contained in the above description or shown
in the accompanying drawings shall be interpreted
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as illustrative and not in a limiting sense.
It is also to be understood that the followi.ng
claims are intended to cover all of the generic and
specific features of the invention herein described,
and all statements of the scope of the invention,
which, as a matter of language, might be said to
fall therebetween.
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