Self-operative steering for radio-controlled model car

A self-operative steering for radio-controlled model car per se operative corresponding to radio-controlling signals transmitted from a controller of the model car. The steering comprises a housing containing a servomechanism therein, a pair of wheel-shaft receiving means with steering means protruded from the both sides of the housing and a tie rod connecting the steering means with the servomechanism in co-operative position. The servomechanism is operative corresponding to the controlling signals to operate the steering means.

BACKGROUND OF THE INVENTION 
The present invention relates to a steering employed for a radio-controlled 
model or miniature car for steering of driving thereof. More specifically, 
the invention relates to a self-operative steering containing therein a 
servomechanism so as to be self-operative corresponding to 
radio-controlling signals transmitted from controller. 
The radio-controlled model car has employed a plurality of various 
controlling means for controlling the driving speed, changing front and 
back-ward movement, and steering in order to perform variable actions. The 
respective controlling means are co-operated with servomechanisms 
respectively provided for the model car corresponding to the controlling 
means. To control or operate one of the controlling means, it is required 
one servomechanism. There are further employed in the model car a decorder 
for discrimination of the various controlling signals and for input the 
signals to the servomechanism which may operate desired controlling means 
for performing sought operations, and a power supply generally being 
electric batteries. On the chassis of the model car, there are arranged 
the aforementioned elements constituting mechanisms of the model car. 
In the prior arts, there are so many elements on the chassis, particularly 
on the portion within wheel base thereof, that may not easily plan the 
arrangement of respective elements. Especially, on planning the 
arrangement of the steering and servomechanism therefor, has been arisen 
troublesome problems to be solved. One of the problems is that, since the 
dimension between the steering and servomechanism is per se defined in 
relationship of each other for exact co-operation, the arrangement thereof 
should be planned in relationship of each other relative to other 
elements. The other problem is that the steering and servomechanism often 
limit the size or width of the chassis where they are mounted in relation 
one another, thus they interfere employment of them in small-sized model 
cars. 
While, it is desirable to exchange various car bodies mounted on single 
chassis with controlling means. As the various car bodies often have 
different wheel bases, it may frequently necessary to adapt the locations 
of the wheels on the chassis corresponding thereto. But, in the 
conventional construction of the model car, it is practically difficult to 
adapt the location of the wheels to various wheel bases of the car bodies, 
since there are so many elements on the chassis that may not allow freely 
locating the wheels with the steering and servomechanism. Thereby, on the 
single chassis, it can be mounted generally one car body of which the 
wheel base is adapted to dimension of the front and back wheels on the 
chassis. This has been required to change car body to obtain or buy the 
chassis with elements adapting the wheel base to the car body. 
Further, since the conventional steerings are supplied as independent 
members separated to servomechanisms, there are required so many parts 
consisting therefor as to result in high-cost of manufacturing or 
production. And moreover, they have required expense for work on 
assembling respective steering and servomechanism separately. Thereby, the 
model kits are so expensive as not to easily buy. 
The invention is to improve disadvantages of the prior arts by way of 
combining the steering and servomechanism as single element capable of 
self-operation corresponding to radio-controlling signals. 
SUMMARY OF THE INVENTION 
Therefore, it is the object of the invention to provide a self-operative 
steering for radio-controlled model car which can be per se operative 
corresponding to radio-controlling signals. More specified object of the 
invention is to provide a steering have a servomechanism therein. 
Another object of the invention is to provide a radio-controlled model car 
employing the self-operative steering to allow exchange of car bodies on 
the single chassis. 
To achieve the above-mentioned and other objects, the self-operative 
steering according to the invention comprises: 
a housing having a pair of wheel-shaft receiving means with steering means 
to rotate the former means, on both sides thereof; 
a servomechanism contained within the housing and including an electric 
motor driven corresponding to controlling signals; and 
a tie rod connecting the servomechanism with steering means so as to steer 
the model car by operation of former. 
Preferably, the housing may be movably secured on the chassis of the model 
car in order to adapt the location of the wheels with the steering to the 
wheel bases of the car bodies for exchanging various car bodies on the 
chassis. 
The steering according to the invention can be per se operative to steer 
the model car corresponding to controlling signals. The above constructed 
steering can allow adapting the location of the wheels on the chassis to 
the wheel bases of the car bodies. Thus, it is no longer necessary to 
expend for the chassis in order to exchange car bodies. And, the steering 
in accordance with the invention can reduce the cost for manufacturing or 
producing by coupling the steering and servomechanism as single element so 
as to decrease the numbers of parts and expense for work on assembling. 
Other objects and advantages of the invention will be described hereinafter 
.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, particularly to FIG. 1, there is illustrated 
a steering 10 according to the first embodiment of the invention with 
wheels 14, equipped or mounted on a chassis 12 of a model car. The 
steering 10 will be arranged on the chassis as to position the wheels 14 
within dents or cut-outs 13 formed on both sides of the chassis. As may be 
apparent, the portion illustrated herewith is a front-side portion of the 
model car, since the steering is generally provided for steer model car by 
controlling the front wheels thereof. 
The steering has a housing 20 being made of plastic materials. However, the 
housing can be made of either plastic materials or metallic materials, it 
is advantageous to make it of plastic materials for easy processing and 
low cost of the raw materials. The housing 20 is secured on the chassis 12 
by bolts or screws 18 received through apertures 16,29 respectively formed 
on the chassis 12 and a base 27 of the housing 20. The apertures 16 are 
provided on the chassis in aligned position so as to capable of 
selectively adapting the aperture 29 thereto for match the wheel base with 
that of car bodies, as shown in FIG. 5. The bolts 18 engage with nuts 19 
through washer 19'. The nuts 19 are fixed on the inner surface of the base 
27. It will be expected that there are various way to secure the housing 
on the chassis in movable position. In FIG. 8, there is illustrated 
another embodiment for securing the housing on the chassis, for an 
example. The housing 20 is provided with projective portions on four 
corners of the base 27 thereof. Each projective portion 29' is formed 
downwardly opened dent with thread formed on the inner periphery thereof. 
The chassis 12 is formed two pairs of elongated slits 17' aligned one 
another to receive bolts 18 and movably secure the housing on the chassis. 
The bolts 18 engage to the thread of the dents through the slits 17' and 
washer 19' so as to allow the housing adapting the location to the wheel 
base of the car bodies. 
The housing 20 is formed lateral slits 22 on side walls 25 through which 
both ends of a tie rod 24 are extended sidewardly from the housing 20. The 
housing 20 is also provided, on the side walls 25, two pairs of triangular 
plates 26 extended sidewardly from the upper and lower portions thereof. 
Each pair of upper and lower triangular plates 26 are provided with a pair 
of apertures 28 aligned one another. Between each pair of triangular 
plates 26, there are equipped with a shaft 30 with axes 34 protruded upper 
and lower ends thereof to engage with the apertures 28. Thereby, the shaft 
30 is rotatable about the axes 34. On the vertical intermediate portion of 
the shaft 30, there is provided with a wheel-shaft receiving means to 
rotatably receive the wheel-shaft 32. A lateral plate 36 is extended from 
the lower portion of the shaft 30 directed backwardly therefrom. The free 
end of the plate 36 are provided with a shaft 38 protruded upwardly which 
has an axis 40 on the top thereof. 
The axis 40 engages with an aperture 44 formed on each end of the tie rod 
24. The tie rod 24 is received in the housing horizontally movable by 
operation of a servomechanism 50 contained within the housing 20. Thus, 
the tie rod 24 pulls and/or pushes the shaft 38 in order to rotate the 
shaft 30 for steering the model car. 
As shown in FIGS. 2 through 4, the servomechanism 50 contained within the 
housing 20 comprises an electric motor 52 connected with a volume 56, and 
a plurality of reduction gears. The motor 52 is preferred a variable motor 
capable of driving in various speed and/or in different direction. The 
volume controls the driving speeds and/or directions of the motor 52 
corresponding to controlling signals for steering the model car in desired 
speed or direction. The volume 56 is mounted on the ceiling 23 of the 
housing. Terminals 55 are protruded from the volume 56 with which the 
volume 56 is connected with a decorder (not shown) by leads 57. 
The reduction gears of the servomechanism can be embodied in various 
numbers, types and combinations of the gears in accordance with desired 
reducing ratios. However, in this embodiment, there are employed first and 
second reduction gears 58, 64 each of which integrally has stepped two 
gear portions 60,62 and 66,68. The gear portions 60, 66 consist small 
gears of the reduction gears and the other portions 62,68 consist larger 
gears thereof. The small gear 66 of the second reduction gear 64 is 
engaged with an operative gear 70. The large gear 62 of the first 
reduction gear 58 engages with a pinion 72 fixed on the top of a motor 
shaft 74. The small gear 60 and the large gear 68 of the reduction gears 
58,64 are interengageable each other. Respective reduction gears 58,64 are 
fixed on axes 76,80 respectively equipped on the base 27 of the housing 20 
through bosses 78,82. The operative gear 70 is fixed to an axis 84 which 
has a portion 86 where the diameter thereof is larger than that of 
remaining portion, under the operative gear 70. A lateral projection 98 is 
protruded from the portion 86 to contact with a pair of aparted 
projections 100 provided on the base 27 of the housing. Thus, the 
projections 98 and 100 function as stopper to limit rotation of the 
operative gears 70. In the preferred embodiment, the projections 100 are 
respectively positioned to have approximate seventy-five degrees of gaps 
from diametrical line of the axis 84 along the longitudinal center line of 
the housing 20. Thereby, the operative gear 70 fixed on the axis 84 is 
limited the rotation within a range respective approximate seventy-five 
degrees in clockwise and counterclockwise from the neutral position. 
A projection 88 is protruded upwardly from the adjacent circumference of 
the operative gear 70. The tie rod 24 is provided with a generally T-shape 
opening 92 comprising a lateral wide portion 94 through which the axis 84 
extends upwardly, and a vertical narrow portion 96, on the central portion 
thereof. The width and length of the lateral portion 94 is defined so as 
not to be interfered the movement of the tie rod 24 by the axis 84. The 
projection 88 is engaged with the vertical or longitudinal portion of the 
opening and movably secured thereto by an equipment 90. The projection 88 
moves the tie rod 24 in the rotation of the operative gear 70 to move the 
shafts 38 sectorially about the axes 34 for horizontally rotate the wheels 
for steering. 
In preferred construction, the distance between the projection 88 and the 
axis 84 is matched with that of between rods 30 and 38 to adequately 
affect the movement of the projection 88 to the rod 30 for exact steering. 
In operation, the radio-controlling signals is transmitted from the 
controller apart from the model car. The controlling signals are received 
through an antenna of the model car and input to the decorder. 
The radio-controlling signals are discriminated on the decorder and fed 
into the servomechanism operating sought controlling means. The 
controlling signals for steering are input to the volume 56 of the 
servomechanism 50 through the decorder. Then, the electric motor 52 starts 
driving corresponding to desired controlling or operation speeds or 
direction. The control of operation speed and/or direction of the motor 52 
is performed by the volume 56 which supplys various electric charge so as 
to control operation speed of the former. 
Rotation or torque of the motor shaft 74 is transmitted to the operative 
gear 70 through the reduction gears 58, 64. On the transmitting the 
rotation, the reduction gears 58,64 reduce the torque into desired ratios. 
Thereafter, the projection is sectorially moved about the axis 84 of the 
operative gear 70. As apparently shown in FIG. 5, the projection 88 moves 
the tie rod 24 in lateral directions. Corresponding to sectorial movement 
of the projection 88, it moves longitudinal direction along the narrow 
portion 96 of the opening 92 of the tie rod 24. When the tie rod 24 moves 
lateral directions, the portion 94 of the opening 92 functions to allow 
the movement thereof without being interfered or effected the movement by 
the axis 84. 
By the lateral movement of the tie rod 24, the shafts 38 are pulled and/or 
pushed lateral direction to sectorially move about the axes 34. According 
to the sectorial movement of the shafts 38, the tie rod 24 is moved 
longitudinal direction. The slit 22 formed on the housing 20 allow the 
longitudinal movement of the tie rod 24 therealong. Thus, the shafts 30 
are rotated with the wheel-shaft receiving means so as to horizontally 
rotate the wheels 14 for steering. 
In preferred construction, dimension between the projection 88 and the axis 
84 is matched with that of between axes 34,40 to match loci of sectorial 
movement thereof. In matching the loci, the projection 88 can exactly 
rotate the shafts 30 for adequate steering. 
The operative gear 70 is limited the rotation directed clockwise and 
counterclockwise within the range respective approximate seventy-five 
degrees from neutral position by contacting the projection 98 to the 
projections 100. Thereby, the projection 88 moves in the range approximate 
seventy-five degrees in the direction clockwise and counterclockwise from 
the neutral position about the axis 84. 
In FIG. 6, there are illustrated a steering 110 in accordance with the 
second embodiment of the invention. The steering 110 comprises a housing 
112 having pairs of triangular plates 120 on both sides thereof, shafts 
114 with wheel-shaft receiving means rotatably equipped between the upper 
and lower triangular plates 120, shafts 118 connected with the shafts 114 
by plates 116 and a tie rod 126 mounted over the housing 112. An axis 124 
is protruded from the top of each shaft 118 and engaged with an aperture 
formed on the end of the tie rod 126. The tie rod 126 is provided on the 
central portion thereof an elongated longitudinally extended slit 132. To 
the slit 132, a projection 130 mounted on an operative gear of the 
servomechanism which is contained within the housing 112, is engaged to 
operate the tie rod 126 in lateral direction. The servomechanism of this 
embodiment is generally similar to the aforementioned first embodiment of 
the invention. 
The housing 112 is formed a slit 128 of an arc of a circle shape to be 
running through the projection 130. The radius of the circle of the slit 
130 is matched with the dimension between the projection 132 and an axis 
of the operation gear. Both ends of the slit 130 may act as stoppers for 
limiting sectorial movement of the projection 130. Each end of the slit 
128 may not exceed the range of ninety degrees from longitudinal center 
line of the housing. Preferably, the ends of the slit 128 are positioned 
approximate seventy-five degrees in clockwise and counterclockwise from 
the center line of the housing 112. Thus, in operation of the 
servomechanism, the projection 130 is moved clockwise and counterclockwise 
from the neutral portion within the range respective approximate 
seventy-five degrees where it contacts to the ends of the slit 128. 
In operation of the steering 110, corresponding to the controlling signals, 
the servomechanism contained in the housing 112, is operative as mentioned 
on the first embodiment. Thus, the projection 130 moves sectorially to 
move the tie rod 126 laterally. By lateral movement of the tie rod 126, 
the shafts 118 are moved sectorially about the shafts 114. Thereby, the 
shafts 114 are rotated to horizontally rotate the wheels for steering. 
In FIG. 7, there is illustrated a steering 140 in accordance with the third 
embodiment of the invention. The steering 140 has a housing made of 
metallic materials, in various metaric materials, it may be preferred 
aluminiums in light weight thereof. A servomechanism 148 is contained 
within the housing 140 with a tie rod 160. The servomechanism 148 
comprises a plurality of reduction gears, an electric motor, preferably 
being a variable motor, 146, a volume controlling the motor 146 in driving 
speeds and directions thereof, and a rack 154 engaging the final reduction 
gear and movable in lateral directions. A guide rail 156 is protruded from 
the side walls of the housing 140, and engaged with the rack 154 for 
guiding the latter on lateral movement thereof. In preferred embodiment, 
the final gear of the reduction gear 148 integrally has a pinion 152 
engaging to the rack 154 for moving the latter in lateral position. On the 
upper surface of the rack 154, there is provided a projection 158 engaging 
to the tie rod 160 in order to co-operate the tie rod 160 with the 
servomechanism 148. 
The tie rod 160 extends both ends thereof from the housing 140. The 
respective ends of the tie rod 160 are connected with axes provided on the 
top of shafts which are connected with wheel-shaft receiving means by 
plates and act as steering means. Thereby, corresponding to operation of 
the servomechanism 148, the tie rod 160 pulls and/or pushes the steering 
means for rotate wheels horizontally to steer. 
However, this embodiment employs the tie rod 160 connected with the rack 
154 by the projection 158, it may be expected that the rack having both 
ends where extend from the housing and engage with the steering means for 
acting as tie rod, in order to operate the steering means without tie rod. 
Preferably, the tie rod 160 is movable about the projection 158 
corresponding to sectorial movement of the steering means. In preferred 
construction, there are provided a longitudinal slit on the central 
portion of the tie rod in alignment of the center line of the housing to 
receive the projection in laterally movable position. 
In operation, the radio-controlling signals are input to the volume of the 
servomechanism through decorder. Corresponding to controlling signals, the 
electric motor 146 starts driving to operate the servomechanism 148. The 
torque or driving of the motor 146 is reduced by the reduction gears and 
fed to the pinion 152 of the final reduction gear. The pinion 152 is 
rotated to move the rack 154 in lateral directions with the tie rod 160. 
Thereby, the tie rod 160 pulls and/or pushes the steering means to 
horizontally rotate the wheels for steering. 
In FIG. 9, there is illustrated a modified embodiment of a volume 170 
connected with a motor (not shown) of a servomechanism, for controlling 
the motor in driving speeds and/or directions. The volume 170 is received 
into a groove 172 formed on a ceiling 174 of the housing. A cover member 
176 having slits 178 on the periphery thereof, is fitted over the volume 
170, of which terminal 180 exporded outwards through the slits 178. 
The cover member 176 is provided a laterally extended fan-shaped element 
182 having a slit 184 of an arc of a circle shape. Through the slit 184, a 
screw 186 is engaged with a thread formed on the inner periphery of an 
opening 188 on the ceiling 174, in order to fix the cover member 176 onto 
the groove 172 of the ceiling 174. 
Thereby, to seek and/or decide a neutral position of the volume, the cover 
member 176 is rotated about the groove 172 together with the volume 170 by 
engagement of slits 178 and terminal s 180. And, thereafter, the cover 
member 176 with the volume 170 is secured onto the groove 172 by the screw 
186 in exact position on neutral. 
Thus, it is apparent that there has been provided a novel and useful 
steering for radio-controlled model car which fulfills all of the objects 
and advantages sought therefor. 
While, specific embodiments of the invention has been shown and described 
in detail to illustrate the application of the principles of the 
invention, it will be apparent that the invention may be embodied 
otherwise without departing from such principles.