U.S. patent application number 10/583455 was filed with the patent office on 2007-06-07 for electric toy vehicle with improved grip.
Invention is credited to Valerio Accerenzi.
Application Number | 20070128976 10/583455 |
Document ID | / |
Family ID | 34717630 |
Filed Date | 2007-06-07 |
United States Patent
Application |
20070128976 |
Kind Code |
A1 |
Accerenzi; Valerio |
June 7, 2007 |
Electric toy vehicle with improved grip
Abstract
An electric toy vehicle is described, said vehicle comprising:
an electric motor, a speed reducer, a power supply batter for
powering said electric motor and moving the vehicle, and at least
two wheels, at least one of which is the driving wheel, at least
one of the wheels having a coefficient of friction greater than
about 0.35. Conveniently, the wheels of the vehicle comprise a
rubber carcass with at least two cross plies of nylon threads.
Conveniently, the vehicle also comprises an electronic control
system for performing a plurality of functions including that of
regulating the power supply voltage to the motor, regulating the
acceleration independently of the load transported; regulating the
deceleration independently of the load transported; managing the
motor brake; controlling the direct-current flow, preventing peak
currents affecting the motor, disabling the functions of the
vehicle at predefined overload values; limiting complete
discharging of the battery and indicating the charging state of the
battery.
Inventors: |
Accerenzi; Valerio; (Bassano
Bresciano (Brescia), IT) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Family ID: |
34717630 |
Appl. No.: |
10/583455 |
Filed: |
December 21, 2004 |
PCT Filed: |
December 21, 2004 |
PCT NO: |
PCT/EP04/14734 |
371 Date: |
January 5, 2007 |
Current U.S.
Class: |
446/465 |
Current CPC
Class: |
A63H 29/00 20130101;
B60L 58/12 20190201; B60L 3/10 20130101; Y02T 10/64 20130101; Y02T
10/70 20130101; Y02T 10/72 20130101; B60L 15/20 20130101; A63H
17/262 20130101; B60L 2200/20 20130101 |
Class at
Publication: |
446/465 |
International
Class: |
A63H 17/00 20060101
A63H017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 23, 2003 |
IT |
MI2003A 002577 |
Claims
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30. An electric toy vehicle intended for being driven by a child
driver while playing comprising: a seat or saddle for the child
driver; at least two wheels, at least one of which being a driving
wheel; an electric motor; a speed reducer which transmits movement
to said at least one driving wheel; a rechargeable power supply
battery for powering said electric motor and moving the electric
toy vehicle; wherein: a) said at least one driving wheel comprises
a rim and a tire fit on said rim, said tire comprising a rubber
carcass and a tread; b) said electric toy vehicle also comprises an
electronic control system configured to regulate the power supply
voltage to the electric motor; c) said electronic control system
also comprises means for regulating vehicle acceleration in a
manner substantially independently of the load transported by the
vehicle, in accordance with a suitable acceleration ramp.
31. The toy vehicle according to claim 30, wherein said electronic
control system also comprises means for regulating the vehicle
deceleration in a manner substantially independently of the load
transported by the vehicle, in accordance with a suitable
deceleration ramp.
32. The toy vehicle according to claim 30, wherein said electronic
control system is programmed so that said electric motor receives
predetermined fractions of the maximum voltage which can be
supplied by said battery.
33. The toy vehicle according to claim 30, wherein said electronic
control system configured to regulate the power supply voltage to
the motor comprises a potentiometer.
34. The toy vehicle according to claim 30, wherein said electronic
control system also comprises short-circuiting means for managing
the motor braking function.
35. The toy vehicle according to claim 30, wherein said electronic
control system also comprises means for controlling the
direct-current flow and preventing current peaks affecting the
motor, typically when starting and reversing.
36. The toy vehicle according to claim 30, wherein said electronic
control system also comprises means for electronically disabling
the functions of the vehicle during recharging of the power supply
battery.
37. The toy vehicle according to claim 30, wherein said rubber
carcass comprises two cross plies cross plies, each of said cross
plies comprising cords made of nylon.
38. The toy vehicle according to claim 30, wherein said tread
comprises blocks and grooves forming a tread pattern providing a
coefficient of friction greater than about 0.35.
39. The toy vehicle according to claim 30, wherein a thickness of
the carcass in sidewall zone ranges between about 1.0 mm and 4.5
mm, more preferably between about 2.0 mm and 3.8 mm, and even more
preferably between about 2.5 mm and about 3.3 mm.
40. An electronic control system for an electric toy vehicle which
is intended for being driven by a child driver while playing, said
electronic control system being configured to regulate the power
supply voltage to the motor and comprising means for regulating
vehicle acceleration in a manner substantially independently of the
load transported by the vehicle, in accordance with a suitable
acceleration ramp.
41. The electronic control system according to claim 40, further
comprising means for regulating vehicle deceleration in a manner
substantially independently of the load transported by the vehicle,
in accordance with a suitable deceleration ramp.
42. The electronic control system according to claim 40, further
comprising short-circuiting means for managing the motor braking
function.
43. The electronic control system according to claim 40, further
comprising means for controlling-the direct-current flow and
preventing current peaks affecting the motor, typically when
starting and reversing.
44. The electronic control system according to claim 40, further
comprising means configured to disable the functions of the vehicle
at predefined overload values.
45. The electronic control system according to claim 40, further
comprising means for electronically disabling the functions of the
vehicle during recharging of the power supply battery.
Description
[0001] The present invention relates to the sector of electric toy
vehicles which are typically intended for transporting children
while playing. In particular, the present invention concerns an
electric vehicle which has numerous advantages owing to improved
grip of the driving wheels on the rolling surface.
[0002] For some years various electric toy vehicles which
reproduce, on a small scale, cars, motorcycles, scooters or the
like, have been known. These known vehicles comprise at least two
wheels, a seat (or saddle, in the case of scooters and motorcycles)
and a metal or plastic frame.
[0003] The vehicles present on the market essentially consist of
three types. The first type is a single-speed vehicle composed of:
two or more blown high-density polyethylene (HDPE) wheels; an
electric motor; a reducer; a wiring system; and a 6 V power supply
battery. The second type is a vehicle with more than one speed,
composed of two or more blown HDPE wheels; two motors, two
corresponding reducers; a wiring system; a 12 V power supply
battery; and a thermal resistance for reducing the speed and for
preventing possible overloads. The third type is a vehicle with
more than one speed composed of two or more blown HDPE wheels; two
motors; two reducers; a wiring system; two 6 V batteries; a
commutator for connecting the batteries in series or in parallel in
order to control the speed; and a system for controlling the
overload by means of inductance.
[0004] It is known that models with more than two driving wheels,
for which a corresponding number of motors/reducers are used, are
available on the market.
[0005] The Applicant has realized that the electric toy vehicles of
the known type have various drawbacks and limitations.
[0006] As regards two-speed vehicles, it is pointed out that, in
vehicles of the second type, which are equipped with a 12 V
battery, the speed is controlled by a thermal resistance which
results in wastage of power. In vehicles of the third type,
however, the speed is controlled by a commutator which allows the
two batteries to be used, depending on the speed set, at 6 V or 12
V. It follows that the actual power consumption is strictly related
to the operating speed. It must also be pointed out that, if, in
the vehicles of the second type, there is a limited operational
autonomy precisely because of the management system used, in the
vehicles of the third type the solution used to solve the same
problem results in increased costs owing to the use of two
batteries and a more complex wiring system.
[0007] The Applicant has established that the known electric toy
vehicles have poor or even zero grip when the vehicle is placed on
surfaces which are substantially smooth (for example marble floors,
tiled floors, etc.), on moist surfaces (grass lawns) or the like.
As a result, the known vehicles, from the standing position, start
with extreme difficulty and in any case struggle to keep to the
steering path imposed by the driver.
[0008] The Applicant has also noted that the wheels of the known
vehicles, which are made of internally hollow rigid plastic act
like a sound box and amplify the noise during movement of the
vehicle, in particular in closed surroundings. As a result, the use
of the electric toy vehicle is particularly noisy, in particular in
surroundings which are substantially closed or in any case
confined.
[0009] Moreover, the Applicant has found that the wheels of the
vehicle, which are substantially rigid, transmit jerks and jolts
when passing over rough ground and greatly limit the comfort
on-board.
[0010] In addition, the traction obtained with the use of a single
motor and with the wheels currently used results in various
difficulties. Moreover, a high power consumption and rapid and
non-uniform wear of the wheels occurs.
[0011] Any attempt to overcome the abovementioned problems with the
use of several motors, several reducers and several batteries
achieves improvements but at the same time results in a reduction
in the operational autonomy and an increase in the cost of the
product. The problem of grip is amplified if the traction of the
vehicle is obtained by using two motors since, when the vehicle
performs a turning movement, one of the two motors suffers a
braking action due to the friction. As, a result, the vehicle loses
its residual adherence, does not keep to the steering path and the
radius of curvature increases. This results in a limited
possibility of using the vehicle in unsuitable surroundings as well
as a difficulty in reversing the direction of travel. Therefore,
if, as usually occurs, the known vehicles are used in confined
spaces, they are affected not only by premature wear of the wheels,
but in particular of the motors and the batteries which are subject
to the stress resulting from continuous braking and from the need
for continuous changes in direction.
[0012] Paradoxically, when the basic structure of the rolling
surface is able to offer good adherence (for example, soft rubber
surfaces, carpets or the like) the starting up and stopping
operations in the case of a known vehicle are excessively sudden,
violent and "unpredictable". In fact, power is supplied (or
interrupted) suddenly (compared to poor grip situations where the
wheels tend to spin) and the driver is unprepared for these sudden
acceleration or deceleration situations. For this reason, the
driver runs the risk of suffering knocks against parts of the
vehicle, in particular against the dashboard and the steering
wheel, and of suffering bruising.
[0013] The Applicant has noted the abovementioned limitations and
has set themselves the object of providing an improved electric toy
vehicle which is safer and more comfortable compared to the present
vehicles of the same type, while maintaining low costs (even lower
than those of the present vehicles).
[0014] These and other objects are obtained by an electric toy
vehicle having the characteristic features described in claim 1 and
by a system for controlling an electric toy vehicle according to
claim 20. The dependent claims specify further advantageous
characteristic features of the invention. All the claims are
considered to form an integral part of the present description.
[0015] According to a first aspect, the present invention relates
to an electric toy vehicle comprising: an electric motor, a speed
reducer, a power supply battery for powering said electric motor
and moving the vehicle, and at least two wheels, at least one of
which is a driving wheel, characterized in that at least one of the
wheels has a coefficient of friction greater than about 0.35,
preferably greater than about 0.5 and even more preferably ranging
between about 0.5 and about 3.0. Conveniently, said at least one
wheel having a coefficient of friction greater than about 0.35,
preferably greater than about 0.5 and even more preferably ranging
between about 0.5 and about 3.0 is a driving wheel. Preferably,
said at least one wheel having a coefficient of friction greater
than about 0.35, preferably greater than about 0.5 and even more
preferably ranging between about 0.5 and about 3.0 comprises a rim
and a tyre, where said tyre is a tyre comprising a rubber
carcass.
[0016] Conveniently, said rubber carcass comprises two cross
plies.
[0017] Preferably, said cross plies comprise cords made of nylon or
the like,
[0018] Preferably, said tyre comprises a tread with a raised
pattern.
[0019] Preferably, the thickness of the carcass in the sidewall
zone ranges between about 1.0 mm and 4.5 mm, more preferably
between about 2.0 mm and 3.8 mm, and even more preferably between
about 2.5 mm and about 3.3 mm.
[0020] According to an advantageous embodiment, said tyre has a
size, expressed in inches, of 10.00.times.5.00-5''1/2
(corresponding, in mm, to 260.times.120-5''1-2). According to a
further embodiment, said tyre has a size, expressed in inches, of
13.times.6.00-7'' (corresponding, in mm, to 330.times.150-7'').
According to yet another embodiment, said tyre has a size,
expressed in inches, of 15.times.7.00-8''1/2 (corresponding, in mm,
to 380.times.180-8''1/2).
[0021] Preferably, said at least one wheel having a coefficient of
friction greater than about 0.35, preferably greater than about 0.5
and even more preferably ranging between about 0.5 and about 3.0
comprises an inner tube and an associated valve.
[0022] According to one embodiment, said vehicle comprises an
electronic control system, which is typically an electronic board,
designed to regulate the power supply voltage to the motor, for
example by means of a potentiometer or a similar device.
[0023] Conveniently, said electronic control system also comprises
means for regulating the acceleration in a predetermined manner
substantially independently of the load transported by the vehicle,
in accordance with a suitable acceleration ramp.
[0024] Conveniently, said electronic control system also comprises
means for regulating the deceleration in a predetermined manner
substantially independently of the load transported by the vehicle,
in accordance with a suitable deceleration ramp.
[0025] Conveniently, said electronic control system also comprises
short-circuiting means for managing the motor braking function.
[0026] Conveniently, said electronic control also comprises means
for controlling the direct current flow and preventing current
peaks affecting the motor, for example when starting and
reversing.
[0027] Conveniently, said electronic control system also comprises
means able to disable the functions of the vehicle at predefined
overload values, so as to avoid, for example, unsuccessful attempts
by a vehicle to overcome an obstacle, for example a wall.
[0028] Conveniently, said electronic control system also comprises
means for limiting complete discharging of the power supply
battery.
[0029] Conveniently, said electronic control system also comprises
means for electronically disabling the functions of the vehicle
during recharging of the battery.
[0030] Conveniently, said electronic control system also comprises
means for indicating the state of charging of the battery, for
example by means of a display or the like.
[0031] The solution adopted allows the optimum use of the vehicle
resources as well as maximum use in terms of operating autonomy,
such that the wiring system uses, for power functions, wires with a
cross-section of about 2.5 mm.sup.2, while for the signalling
functions the cross-section of the wires is reduced to about 0.5
mm.sup.2.
[0032] The present invention will certainly become clear from the
detailed description which follows, provided by way of a
non-limiting example, to be read with reference to the accompanying
illustrative plates of drawings, in which:
[0033] FIG. 1 shows the layout of the transmission of an electric
toy vehicle of the first known type, having one speed;
[0034] FIG. 2 shows the layout of the transmission of an electric
toy vehicle of the second known type with more than one speed;
[0035] FIG. 3 shows the layout of the transmission of an electric
toy vehicle of the third type with more than one speed;
[0036] FIG. 4 shows a layout of the transmission of an electric toy
vehicle according to the present invention;
[0037] FIGS. 5a and 5b show cross-sections through a tyre according
to the present invention and a known tyre for agricultural use;
[0038] FIG. 6 shows schematically an electronic control system
according to the present invention.
[0039] The same reference numbers will be used to indicate the same
parts or components which are functionally equivalent.
[0040] FIGS. 1, 2 and 3 show three layouts of the transmissions of
respective electric toy vehicle of the known type. The first layout
is generally used in toy vehicles which are recommended for little
children. The second and the third layouts are generally used in
toy vehicles which allow transportation of one or more passengers.
It is useful to clarify henceforth that the term "electric toy
vehicle" (or equivalent terms) shall be understood in this
connection as referring to any vehicle with two, three or four (or
more) wheels, which is powered by direct current at 6 V (or 12 or
24 V), recommended (depending on the models and the drive system)
for children having an age of between about two years and ten
years.
[0041] The layout according to FIG. 1 provides for a motor 1 which
is powered by a (6 V) battery 2 and a speed reducer 3 (shown in an
exploded view) which is connected to a wheel 4 (driving wheel). The
wheels 4 and 5 are both made of HDPE and have a coefficient of
friction, at room temperature, ranging between 0.08 and 0.2
measured in accordance with the Standard ASTM D1894 "Standard Test
Method for Static and Kinetic Coefficients of Friction of Plastic
Film and Sheeting". The layout according to FIG. 1 also shows a
pedal-operated switch P and a device 1 for reversing the direction
of travel.
[0042] The layout according to FIG. 2 provides for two motors 1,
which are powered by a single (12 V) battery 2, and two
corresponding speed reducers 3 (shown in an exploded view) which
are connected to respective wheels 4 and 5. The wheels 4 and 5 are
made of HDPE and have a coefficient of friction, at room
temperature, ranging between 0.08 and 0.2 measured in accordance
with the Standard ASTM D1894. The layout according to FIG. 2 also
shows a pedal-operated switch P, a device I for reversing the
direction of travel and a selector for changing gear.
[0043] The layout according to FIG. 3 provides for two motors 1
which are powered by two respective (6 V) batteries 2 and two
corresponding speed reducers 3 (the right-hand one shown in an
exploded view) connected to respective wheels 4 and 5. The wheels 4
and 5 are made of HDPE and have a coefficient of friction, at room
temperature, ranging between 0.08 and 0.2 measured in accordance
with the Standard ASTM D1894. The layout according to FIG. 2 also
illustrates a pedal-operated switch P, a device I for reversing the
direction of travel and a selector M for changing gear. The
selector M also comprises a commutator for connecting the batteries
in series or parallel in order to control the speed. The layout
according to FIG. 3 also comprises a device 6 for controlling the
overload by means of inductance.
[0044] The layouts according to FIGS. 1, 2 and 3 all have the
problems and the limitations listed in the introductory part of the
present description.
[0045] A layout of the transmission of an electric toy vehicle
according to the present invention is shown in FIG. 4.
[0046] The layout according to the present invention comprises an
electric motor 11, a (12 V) battery 12 for powering the motor 11
and a speed reducer 13 which transmits the movement to a wheel 14.
Unlike the known layouts, at least the wheel 14 connected to the
speed reducer (but preferably also the other wheels 15 of the
vehicle) is substantially soft and has a coefficient of friction
greater than about 0.35, preferably greater than about 0.5 and even
more preferably ranging between about 0.5 and about 3.0. Depending
on the specific use of the vehicle, the coefficient of friction
may, in particular, range between about 0.5 and 1.0, between about
1.0 and 1.5, between about 1.5 and 2.0, between about 2.0 and 2.5
or between 2.5 and 3.0. Tyres with coefficients of friction greater
than 3.0 are also possible, in particular when it is envisaged
using the vehicle on particularly smooth and slippery surfaces.
[0047] FIG. 5a illustrates, by way of example, a cross-section
through an embodiment of a tyre 141 of a wheel 14 according to the
present invention. The tyre 5a has a size 10.times.5.00-5''1/2
(corresponding, in mm, to 260.times.120-5''1/2). The first number
indicated represents the outer diameter, the second number
represents the cross-section and the third number represents the
fitting diameter generally always expressed in inches. FIG. 5b
instead shows a cross-section through a tyre available on the
market for agricultural use. The tyre according to FIG. 5b is
produced under the trade name "DURO" and has a size of
11.times.4.00-5''. The tyre 141 according to the present invention
comprises a carcass and two sidewalls which terminate in respective
beads. Preferably, the tyre also comprises a tread with radially
projecting blocks and grooves for a greater grip of the vehicle.
The carcass is formed by two cord cross plies. Preferably the cords
are textile or nylon cords arranged with a density comparable to
that of a bicycle tyre or the like. FIGS. 5a and 5b shows some
significant dimensions of the two tyres compared. In particular,
the carcass thickness of the tyre according to FIG. 5a along the
sidewalls is about 3 mm, while that of FIG. 5b is about 7 mm.
[0048] The recorded weight of the known tyre (FIG. 5b) is about
1.875 kg, while the weight of the tyre according to the invention
(FIG. 5a) is less than half and equal to about 0.85 kg. Therefore,
the comparison has shown how a tyre which equips a vehicle
according to the present invention is much lighter and more
economical than a similar known tyre for agricultural use. The
characteristic feature of lightness is very important since an
electric toy vehicle must be light in order to have acceptable
performance features and limit the wear of the motor and
consumption of power by the battery. The characteristic feature of
economy is also very important in vehicles of this type and is due
mainly to the saving of rubber material (reduced thickness of
carcass) and to the consequent shorter vulcanization times.
[0049] According to a preferred embodiment, each tyre 141, 151 is
mounted on a rim 143, 153, for example made of plastic, composite
material or metal, with an inner tube (not shown). According to an
alternative embodiment, the tyre 141, 151 is of the tubeless type,
i.e. without an inner tube. This second embodiment requires a
greater precision in machining of the rim and is therefore less
preferred.
[0050] The fact of having equipped the vehicle with a driving wheel
having a coefficient of friction greater than about 0.35,
preferably greater than about 0.5 and even more preferably ranging
between about 0.5 and about 3.0 has enabled substantially all the
problems of the known art indicated above to be overcome. Firstly,
a vehicle according to the invention is easier to start from
standstill and easier to keep along the steering path of the
driver. It has also solved the problems associated with the noise
of the wheels on the rolling surfaces. Moreover, the travel comfort
is much improved owing to the softness of the tyres compared to the
rigid wheels of the known vehicles.
[0051] The wear of the tyres is practically negligible and in any
case substantially uniform also without using two separate
motors.
[0052] According to a particularly advantageous embodiment, the
motor 11 is managed by means of a special control system 17.
[0053] The fact of using a single electronically managed motor,
associated with tyres having a coefficient of friction greater than
about 0.35, preferably greater than about 0.5 and even more
preferably ranging between about 0.5 and about 3.0 greatly improves
the drivability of the vehicle and allows use thereof also in
relatively confined spaces. The Applicant, in fact, has noted a
significant reduction in the minimum steering radius compared to
the known electric toy vehicles, namely from about 2.0-3.0 m (for a
known four-wheel vehicle) to about 0.5-1.5 m (for a similar vehicle
according to the invention).
[0054] According to a first aspect, the control system 17 is able
to regulate the power supply voltage to the motor and therefore the
speed of the vehicle. The electronic control system 17 preferably
consists of an electronic power and signalling board.
[0055] As shown schematically in FIG. 4, the control system 17
co-operates with one or more of the following devices: a pedal-type
switch P, a key-operated switch C, a device I for reverse travel, a
selector M for changing gear M; an acoustic device A (horn or the
like); a display VB for charging the battery; one or more
illumination lamps (front LH "LA_SX", front RH "LA_DX", rear LH
"LP_SX" and rear RH "LP_DX"); and a socket 182 for recharging the
battery. Conveniently, the electronic control system 17 is
programmed so that the motor receives predetermined fractions of
the maximum voltage which can be supplied by the battery. For
example, if the maximum voltage which can be supplied by the
battery is 12V, the electronic control system may be programmed so
as to supply to the motor a first fraction of 3 V, a second
fraction of 6 V, a third fraction of 9 V or the whole voltage of 12
V.
[0056] The supplying of these voltage fractions may be controlled
by the driver (child), may be factory-set, may be determined by an
adult or may be a combination of the abovementioned options. In the
first case, the child will have access to a speed selector and will
be free to choose the speed which is most suited to the
circumstances. In the second case, it will be the manufacturer who
determines the maximum speed for each type or category of vehicle
(this means that, while maintaining the same components, it is
possible to construct electric toy vehicles for children who are
less expert or for older children). Alternatively, the setting is
left to an adult, providing a first selector in a zone which is
inaccessible for the child and, if necessary, a second selector
which can be operated by the child/driver. This solution is
advantageous because it allows an adult to set the maximum
permitted speed of the vehicle depending on the age and the actual
abilities of the child.
[0057] Preferably, said electronic control system 17 is programmed
so as to provide a predetermined acceleration ramp 171 independent
of the load transported by the vehicle. FIG. 6 shows an embodiment
of an acceleration ramp 171 and deceleration ramp 172. FIG. 6 also
shows a reversing travel ramp 173. According to the present
invention, the maximum speed of the electric toy vehicle (of the
order of 8-10 km/h) is reached after a certain time interval (of
the order of 3-4 seconds). According to the ramp shown in FIG. 6,
the acceleration of an electric toy vehicle starting in 4.sup.th
gear (selector in position 4) is the same as a vehicle which starts
in 1.sup.st, 2.sup.nd or 3.sup.rd gear; the difference lies in the
maximum speed which can be reached without making further gear
changes. The same concept applies to the deceleration phase.
[0058] In any case, the acceleration or the deceleration of the
vehicle according to the present invention is independent of the
load transported. This solves a very common problem in the known
electric toy vehicles where the smaller the weight (i.e. a younger
and hence more inexpert child) the greater the acceleration and the
greater the whiplash effect affecting the vehicle and hence the
driver of the vehicle.
[0059] Moreover the motor braking effect provided by the electronic
control system combined with the grip of the tyre according to the
invention favours the stoppage of the vehicle without causing a
sensation of discomfort for the driver which is implicit in known
vehicles since the stoppage occurs in a controlled, predictable and
safe manner.
[0060] Moreover the electronic control system allows control of the
voltage supplied by the battery to the motor during the starting
movement and reversing, preventing the motor being subject to
uncontrolled electric discharges (sparks between brushes and slip
rings which cause motor wear) and the battery having a shorter life
owing to the consequent stress.
[0061] Moreover, the electronic board fixes overload values of the
motor (for examples vehicles against an obstacle), protecting it
from the stress due to unnecessary operation during a standing
start and wear of the wheels which are forced to spin.
[0062] According to a preferred embodiment, the electronic control
system 17 provides a closed-loop speed electronic control which,
irrespective of the payload, keeps constant a pre-established speed
in any travel condition such as on flat ground, during ascents or
descents. According to the present invention, a sensor detects the
number of wheel turns and conveys such a detected number of turns
to the board. The board compares a set speed with the detected
speed and it supplies: a) more energy if the comparison results in
a negative value (ascent); or b) less energy if the comparison
results in a positive value (descent).
[0063] In case the requested energy is less than zero, (the vehicle
is driving along a steep descent), the motor acts as energy
generator and it inverts the flow. This effect is used so that the
motor is electronically bypassed (see connection 19) and it acts as
exhaust brake.
[0064] This results in a safer vehicle (exhaust brake during steep
descents) and in a more effective energy management (the power
consumption becomes strictly dependent on the type of traveled
ground).
[0065] In order to regulate different speeds of the vehicle, an
electronic-type magnetic selector is provided, said selector being
stepwise and it is preferably regulated by a mechanical switch
arrangement. The mechanical switch arrangement is preferably
provided on the gear lever (for toy car vehicles) or hand grip (for
toy motorcycles or scooters) for setting the gear. The speed is
regulated through a magnetic sensor which, once the position of the
gear lever (or hand grip) has been detected, communicates it to the
electronic board. The electronic system regulates the maximum speed
set according to the gear selected by the user.
[0066] Moreover, the electronic control system predefines (174) a
maximum limit of use of the battery in order to prevent complete
discharging thereof. This is not to the detriment of the vehicle's
autonomy, since the vehicle loses only an insignificant part of its
autonomy in this connection. As a result, since the battery cannot
become completely discharged, it may be fully recharged, something
which otherwise would not be possible, and the operating life of
the battery is also increased about three or four times compared to
that which occurs in known vehicles. The above does not increase
the consumption of electric power by the battery which, in the
layout adopted according to the present invention, is relatively
low and allows a greater degree of autonomy to be obtained compared
that which is achieved with the known layouts involving two
motors.
[0067] Moreover, operation of the vehicle during recharging of the
battery may be disabled electronically as a result of the
electronic control system 17 (for example by means of simple
introduction of a jack 181 of a battery charger 18) and not
mechanically (as occurs in the known vehicles), allowing the user
to perform the necessary recharging operations in absolute safety
and very simply. On the other hand, in the known vehicles, it was
required to disconnect the terminals of the battery in order to
prevent a child attempting to use the vehicle during recharging of
the battery. The operation was laborious, awkward and
time-consuming also because it was required to remove the seat or
the saddle in order to gain access to the battery compartment.
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