[0001] This invention relates to tracks for electric toy cars, and more particularly, to
a control unit for a toy car track having runways to be connected to an electric power
supply for operating the cars, and a passage detector and lap counter associated with
each runway.
[0002] As is known, in many distance racing events, the cars taking part in the race require
tire replacement at least once during the race, due to the high rate of wear to which
they are subjected.
[0003] The tire type is selected to suit the race track characteristics as well as environmental
conditions (nature of the blanket, temperature, wet weather, etc.). In particular,
an outstanding feature of tires is the quality of the rubber used for their treads.
In general, soft rubber tires have good roadholding properties and allow of higher
speeds, but wear rapidly, whereas hard rubber tires have not so good roadholding properties
and allow of lower speeds, but wear less rapidly.
[0004] Since a tire exchange operation takes significant time, tires should be selected
with a view to minimizing the number of stops for their replacement, without losing
sight of the limitations to the average speed that excessively hard tires would impose.
That is, a compromise must be struck between the number of replacements required and
average speed around the track in the light of the event duration and the track peculiarities.
[0005] It is the object of this invention to provide a control unit of the kind specified
in the preamble which enables the problems connected with the choice of the tires
to be simulated.
[0006] This object is achieved, according to the invention, by the provision of a control
unit as defined and characterized in the appended claims.
[0007] The invention can be more clearly understood by having reference to the following
detailed description of a non-limitative embodiment thereof, to be read in conjunction
with the accompanying drawings, wherein:
Figures 1 and 2 are a plan view and side view, respectively, of a control unit according
to the invention, incorporating a layby for tire replacement linked to a track section;
and
Figure 3 is a block diagram of one of the circuits in the control unit of this invention
serving the logic functions involved by the tire replacement simulation.
[0008] With reference to Figures 1 and 2, generally shown at 1 are the control panel of
the control unit and an attached layby for tire replacement, which panel can be wired
to a DC voltage supply, not shown, through leads and a connector indicated at A in
the drawing, both for energizing the car, not shown, motors and the control unit circuits.
[0009] The control panel 1 is connected electrically through leads and a male connector
indicated at B in the drawing to a female connector K on a car track of which only
a straight section is shown generally at 3, and mechanically to the car track by a
linking plate 5 which serves as a tire replacement layby or pad.
[0010] The car track has two grooves 7 and 9 extending parallel to each other and being
adapted to receive a dowel depending from the car undersides to hold them guided around
the track. Associated with each groove is a runway comprising two rails 7a and 9a
of metal which are connected electrically, in a manner not shown, to the live terminals
of connector K. Each runway constitutes an electric contact pair through which the
car motors can draw power by means of wiping contact shoes conventionally arranged
on the car undersides.
[0011] The control panel 1 has two pairs of female connectors 11 a and 11 for electrically
connecting two potentiometers, not shown because conventional, to be operated manually
by the players. It also includes an on/off switch 13 with light indicator 14, a switch
15 for cutting out the tire replacement simulation function, two switches 17a, 17b
for selecting between soft tires (M) and hard tires (D), and two light indicators
19a, 19b to indicate that the tires require to be replaced and two light indicators
21 a, 21 b to indicate the end of a race.
[0012] Aligned on the adjacent portion of the control panel 1 to the layby 5 are four tires
23A, 23B for installation on the toy cars, two each, to simulate tire replacement.
They are each fitted over a stub shaft 24a, 24b constituting the control member of
a respective switch, not shown, which when closed by application of a slight pressure
on fitting the tire is operative to acknowledge the replacement to the simulation
logic circuits.
[0013] The simulated tire replacement is based on the following principles.
[0014] The choice of hard tires entails lower top speed and increased number of laps using
the same tires.
[0015] The choice of soft tires entails higher top speed and decreased number of laps using
the same tires.
[0016] On completion of the set number of laps for a given tire type, the top speed is lowered
significantly.
[0017] Directly after replacing the tires, the top speed is restored to its set value for
the tire type of choice.
[0018] The number of laps in a complete race is appreciably larger than the allowable number
of laps using the same tires, so that at least two tire replacement stops will be
necessary.
[0019] According to the invention, the above-described simulation logic is implemented by
an electronic circuit mounted inside the control panel 1. That circuit is illustrated
by the block diagram of Figure 3. For simplicity of illustration, the diagram only
covers the circuit associated with one of the two runways; the circuit associated
with the other runway being identical with that shown.
[0020] Indicated at Mo is the motor of a toy car, and at 25 the voltage regulating circuit
for connection, through the on/off switch 13, to a voltage supply 27 external of the
circuit. The regulator 25 is connected to the previously described, manually operated
potentiometer which is connected to the connector 11 a on the control unit.
[0021] The circuit comprises a counter 29 for the total number of laps that have been run,
e.g. 30, and a counter 31 for the partial number of laps run. Both counters are controlled
from a passage detector 33, e.g. a mechanical detector no further illustrated in the
drawings. which is installed at a selected location around the track to issue a signal
each time that a car runs past said selected location. The output terminal of the
total lap counter 29 is connected to the regulator 25 to supply it with a race end
signal whereupon the regulator will cease to supply voltage to the motor M through
the runway.
[0022] The limit number of laps is set on the partial lap counter 31 from the tire selection
switch 17a, already described in connection with Figure 1, and in this embodiment,
is of 10 for the selection of hard tires (setting D of the switch), and 8 for the
selection of soft tires (setting M of the switch). The switch 17a is also connected
to the regulator 25 to activate suitable circuitry means of the regulator to set for
a higher supply voltage with the switch in position M and a lower supply voltage with
the switch in position D, whereby the top speed of the motor M will be correspondingly
higher or lower.
[0023] The partial lap counter 31 has its output terminal connected to circuitry means 35,
in turn connected to the regulator 25 for setting a very low supply voltage, and hence
a very low top speed, upon the counter 31 reaching the preset lap count. Finally,
the block 37 represents the circuitry elements, activated by the switch 23A, which
acknowledge completion of the tire replacement, clearing the partial lap counter 31
and inhibiting operation of the circuitry means 35, that is resetting the top speed
defined by the position of the switch 17a.
[0024] From the foregoing, how the control unit is used and the game played is apparent.
[0025] Once the track has been assembled and the control unit connected thereto by interlock
and interfit connections of customary types, the supply connector A and connector
B for coupling to the track are plugged, as are the two manually controlled potentiometers,
in the connectors 11 a and 11 b. The cars are disposed on the track with the guiding
dowels into the respective grooves 7 and 9. The switch 15 is set to the on position
for the tire replacement simulation function. Each of the two players chooses the
tire type that he will use for the race using switches 17a and 17b; this results in
the circuit associated with each of the two runways being set to define the limit
count in the partial lap counter 31 and the maximum supply voltage, that is the top
limit speed. The on/off switch 13 is set to the on position, and the race can start.
[0026] Upon the partial lap counter 31 of either circuit reaching the set limit count, its
respective tire replacement indicator 19a and 19b goes on and the car associated with
that circuit is slowed down materially. The player shall then take the car to the
pad 5 and physically exchange the tires with the spare ones 23a or 23b stored on the
control unit. On completion of the replacement operation, he shall fit the replaced
tires over their holders pushing them down and in so doing, actuate the replacement
acknowledge switches, whereupon the partial lap counter 31 is cleared and the set
supply voltage restored to maximum. The race can be now resumed. At each stop for
tire replacing, the player can decide in favor of the tire type previously used or
the other type.
[0027] Upon the total lap counter 29 reaching the preset limit count, in this embodiment
30, the regulator 25 will remove the voltage to the runway and the race be terminated.
To re-activate the system and start a new race, it will be sufficient to act on the
on/off switch 13 moving it to the off position, so as to clear the counters, and then
again to the on position.
[0028] While a single embodiment of the invention has been described and illustrated, it
is obviously possible to apply many changes and modifications without departing from
the scope of the invention. As an example, the runways, and hence the racing cars,
could be more than two; in this case, a circuit should be provided like that shown
in Figure 3 for each additional runway, as well as, of course, the necessary additional
connectors and control members; also, more than two positions could be provided for
the tire selection switches; in this case, the circuit would have to be altered to
provide for the setting of other limit counts in the partial lap counter 31 and other
corresponding top speeds.
1. A control unit for a track for electric toy cars, having at least one runway (7a,9a)
to be connected to an electric power supply (27) for operating a car, and a passage
detector (33) associated with each runway at a predetermined location, adapted to
send a signal to the control unit upon a car moving along the runway past the predetermined
location,
said control unit comprising a control panel (1) and, for each runway, a supply voltage
regulator (25) and a total lap counter (29) driven by the signal from the passage
detector (33) and adapted to send a signal to the supply voltage regulator (25) upon
a set lap count being reached to remove supply voltage to the runway, and being characterized
in that it further comprises, for each runway:
a tire selection switch (17a,17b) having at least two setting positions on the control
panel (1
first circuitry means incorporated to the supply voltage regulator (25) and adapted
to set the supply voltage to a first predetermined value according to the switch (17a,17b)
position,
a partial lap counter (31) controlled by the signal from the passage detector (33)
and adapted to output a signal upon a set partial lap count being reached according
to the switch (17a,17b) position,
second circuitry means (35) connected to the supply voltage regulator (25) and the
partial lap counter (31) output and adapted to set a supply voltage of a second value,
substantially lower than the first, upon the signal being output from the partial
lap counter (31), and
means of acknowledging completion of the tire (24a,24b) replacement, connected to
the partial lap counter (31) and the second circuitry means (35) and adapted to clear
said counter and inhibit the action of said second circuitry means.
2. A control unit according to Claim 1, characterized in that the tire replacement
completion acknowledge means are switches whose control members are stub shafts (24a,24b)
standing proud of the control panel (1) and being shaped to receive spare tires (23a,23b)
fitted thereover, and are pressure operable upon fitting the tires.
3. A control unit according to either Claim 1 or 2, characterized in that the control
panel (1) is linked mechanically to the car track (3) by means of a linking plate
(5) which acts as a layby for tire replacement.