BACKGROUND OF THE INVENTION
This invention relates to a starting device and, more particularly, to an electronic starting device to permit accurate starting and timing of races.
A continuing search for an improved method for conducting races in athletic competition has resulted in many solutions. Sound generating devices for starting races have been long used, but have met objections in the past in that proper placement of the sound source to permit equality in reception of audible signals by all contestants has been difficult to obtain. A typical example of the prior art is the well-known starting pistol, although in recent times attempts have been made to use other sound sources so as to more accurately measure the elapsed time of a race by means of automatic timers.
Often races are decided by only a fraction of a second; therefore, the seemingly minimal delay between the times the various contestants receive the start signal, occasioned by the length of time required for the sound to travel the width of the racing lanes, has become increasingly important in the athletic field. Already many collegiate rules prohibit timing of races by means of an audible starting cue, for the timing of races is generally done from the finish line and sound travel delays do not permit accurate timing of the event. Therefore, a visual starting cue, for timing purposes, has been necessary.
Athletic organizations presently use starting guns to begin these events, whereby the concentration of the athlete, which is easily fixed on an audible starting cue, is retained, while at the same time, the flash of the gun is used for timing the event. The problem is not completely solved by this method, however, since officials firing the gun must necessarily be stationed closer to one contestant than another when more than one contestant is involved, the official not being permitted to stand behind the contestants.
As an example of this, sound travels at 1,120 feet per second. A typical time for the 50-yard freestyle swimming race is 21 seconds. A contestant's average rate of travel is then (50 yards)(36)/(21 seconds) or 85.68 inches per second. If starter stands in the vicinity of swimmer No. 1, say 8 feet forward, then swimmer No. 6 will be located approximately 40 feet away. Swimmer No. 1 loses (85.68)(8)/1,120 or 0.61 inches, while swimmer No. 6 loses (85.68)(40)/1,120 or 3.06 inches. This results in a maximum loss of 2.45 inches swimmer No. 6 suffers when compared to swimmer No. 1.
A second example might occur in the 100-yard dash in track. A sample time for this event is 10 seconds, resulting in an average running speed of (100)(36)/10 or 360 inches per second. A starter gun once again located 8 feet from contestant No. 1 would be located approximately 25.3 feet from contestant No. 6. Contestant No. 1 then losing (360)(8)/1,120 or 2.57 inches while contestant No. 6 loses 8.15 inches, a maximum difference of 5.58 inches.
SUMMARY OF THE INVENTION
It is, therefore, an object of this invention to provide an electronic starting means which will include an audible as well as visual cue for beginning races.
Another object of this invention is to provide an electronic starting means which will allow proper advantageous positioning of the athlete by permitting him to concentrate on an audible cue, while at the same time, prevent him from suffering a belated starting signal due to a difference in the sound travel interval.
Another object of this invention is to provide a means for accurate timing of these events from a point other than the starting line.
These objects are accomplished in the present invention by incorporating a flash signal with a sound system of special construction. The sound system consists of a sound generator circuit connected to a series of speakers placed between alternate starting blocks, thereby eliminating significant differences in the sound travel interval to various contestants. A flash device, which operates in the same generator circuitry, will be triggered simultaneously with the audible signal from the speakers. The flash device will, therefore, provide the visual cue for timing the event.
The system, as will be described, will also be readily adaptable for electronic timing in the event such timing of races will be permitted in the future.
BRIEF DESCRIPTION OF DRAWINGS
The foregoing and additional objects, features and advantages of the invention will be apparent to those skilled in the art from the following description, taken with the accompanying drawing, in which the FIGURE shown is a schematic diagram of the flash and sound circuitry of the present invention.
DESCRIPTION OF A PREFERRED EMBODIMENT
Referring more particularly to the drawing, the FIGURE illustrates in a schematic manner the sound-flash combination of the present invention in connection with a typical arrangement of loudspeakers adjacent the starting positions of a plurality of racing lanes. The flash circuit consists of a suitable flashbulb and a pulse generating means, the pulse being produced by a storage capacitor interconnected through suitable switches and relays to a battery and to the bulb. The capacitor is first charged and thereafter connected across the flashbulb to produce the desired visible start signal. The capacitor is also connected in a second discharge circuit which includes a transformer primary winding, the secondary of the transformer producing a pulse which is amplified and fed to the loudspeakers to provide the required sound signal for the start. Because the response time of the circuit is very short, no appreciable delay is encountered between the time the flash is seen and the starting sound is produced and, by reason of the spacing of the loudspeakers, all starters will receive the start signal simultaneously.
The flash circuit is controlled by a pair of push button switch contacts 10 and 12 which are interconnected so that one or the other is closed, but not both. Preferably, the switches are conventional mechanically interlocked devices, but it will be apparent that any desired type of switch may be used. The contacts associated with push button 10 are normally closed, while those associated with button 12 are normally open, as illustrated in the drawing. The normally closed contacts of switch 10 connect a suitable source of current such as a battery 14 across a storage capacitor 16, the charging circuit being traced from the positive side of the battery, through line 18, switch 10, line 20, normally closed contact 22 and contact arm 24 of a relay 26, through line 28, capacitor 16 and line 30 back to the negative side of the battery.
Relay 26 is illustrated in its de-energized, or normal condition, with its movable arm 24 touching contact 22. In its energized condition, arm 24 moves away from contact 22 and closes contact 32. Relay 26 also includes a second movable arm 34 which is in its upper position to close contact 36 when the relay 26 is de-energized and is moved downwardly to close contact 38 when the relay is energized.
With relay 26 de-energized, the closed contact 10 maintains a bias voltage for the system amplifier 40. The bias connection is from the positive side of battery 14 through line 18, switch 10, line 20, relay arm 34 and relay contact 36 to line 42 and amplifier 40. The negative bias to the amplifier is provided by way of a line 44 connected between the amplifier and the negative side of battery 14.
With switch 10 closed, capacitor 16 charges to the battery voltage, and the system is then ready for operation to produce a starting flash and sound signal. This is accomplished by closure of switch 12 and the simultaneous opening of push button switch 10. The opening of switch 10 removes battery 14 from the circuit. At the moment of switching, capacitor 16 is connected across a suitable flash lamp 50, the connection being from capacitor 16 through line 30 to the flash lamp 50, thence through line 52, contact 12, line 20, contact 22 and corresponding relay switch arm 24, which, for the moment, remains in the de-energized position. The circuit is completed back to the capacitor 16 by way of line 28. The flashing of lamp 50 causes a partial discharge of capacitor 16. At the same time, capacitor 16 energizes the coil of relay 26 by way of line 28, movable arm 24, contact 22, line 20, switch 12, line 54, the relay coil, and line 56 to the negative side of battery 14 and thence to capacitor 16. The energization of this relay is delayed slightly, to enable the flash lamp to operate; thereafter, movable arms 24 an 34 shift to contacts 32 and 38, opening the first discharge circuit connection between capacitor 16 and flash lamp 50. At the same time, a second discharge circuit is completed between capacitor 16 and the primary winding 60 of a pulse transformer 62. This connection may be traced from one side of capacitor 16 through line 28, movable arm 24, contact point 32 and line 64 to the lower end of winding 60, thence through the primary winding to the other side of the capacitor. The capacitor then completes its discharge through the primary winding, producing an output pulse in the secondary winding 66 which is applied to the input of amplifier 40 for amplification and generation of the desired sound signal, as will be described.
The energization of relay 26 also shifts relay arm 34 to its lower contact 38, thereby removing the bias voltage from amplifier 40. However, the amplifier is capable of operating for a short period after the shifting of relay arm 34 by reason of the capacitive and inductive components in the amplifier, thereby permitting amplification of the output pulse from transformer 62. Closure of contact 38 provides a shunt for contact 12, and insures that relay 26 will remain energized even after release of push button 12. The mechanical interconnection between buttons 10 and 12 causes button 10 to return to its normally closed position upon release of push button 12, and if this is done while relay 26 is still energized, a circuit will be completed from the negative side of battery 14, through line 56 and the coil of relay 26, through line 54, lower contacts 38, movable arm 34, line 20, push button 10 and line 18 to the positive side of the battery. This path will hold the relay in its energized position and will assure a complete discharge of capacitor 16 through primary winding 60 and will hold the capacitor in this connection to prevent its recharge and an accidental second discharge after the start of the race.
If a second "call back" signal is required, depression and release of button 12 will de-energize relay 26 and permit the capacitor to charge. Thereafter, button 12 can again be depressed to produce a second sound if there has been a false start in the race.
Amplifier 40 is a standard pulse amplifier of any desired type, preferably having an output transformer 70. The pulse produced by the discharge of capacitor 16 through primary winding 60 is shaped and amplified by the amplifier, producing a pulse of sufficient amplitude across the secondary of the output transformer 70 to provide the desired starting sound. One side of the secondary winding 72 of the output transformer is connected by way of line 74 to the base of a transistor switch 76 which is connected in an emitter follower configuration. The emitter of transistor 76 is connected through load resistor 78 and volume control potentiometer 80 to a speaker output line 82. The collector of the transistor is connected through line 84 and resistor 86 to the other side of the output winding 72 of transformer 70, the junction between resistor 86 and winding 72 being connected through an isolating diode 88 to the junction of resistor 78 and potentiometer 80. Line 84 is also connected through a speaker switch 90 and through a bias battery 92 to a second output line 94. Speaker switch 90 permits the speakers to be disconnected from the circuit if it is desired to provide a visual signal only.
Output lines 82 and 94 are connected in parallel to a series of loudspeakers 95, 96, 97 which are placed adjacent a plurality of racing lanes 100-105. As illustrated, each speaker is placed between two adjacent lanes whereby the output pulse produced by amplifier 40 produces a simultaneous starting signal at each loudspeaker, whereby all contestants will receive the start signal at the same time, and they will all have an equal opportunity to start at the proper time.
Following the operation of the circuit, with button 10 closed, the battery 14 is charging capacitor 16 and providing a bias voltage for the amplifier 40. When it is desired to start the race, button 12 is pushed, opening button 10 and disconnecting battery 14. At the same instant, capacitor 16 is momentarily connected across flash 50 through button 12, now closed. This partial discharge, serves to energize flash 50 and to provide the visual start signal for use by the race timers, who may be at the far end of the track. The relay coil 26 is also energized by this discharge, and switches arms 24 and 34 from points 22 and 36 to points 32 and 38. The capacitor 16, therefore, continues to discharge through the primary side of transformer 62 and provides a pulse input to amplifier 40. When the output from amplifier 40 is present on the base electrode of transistor 76, the transistor begins to conduct and permits current flow from battery 92 to loudspeakers 95, 96, 97 to provide the necessary audible starting signal.
Although the present invention has been described in terms of a single preferred embodiment, it will be apparent to those skilled in the art that a number of modifications and changes can be made without departing from the true spirit and scope of the invention. For example, the output from amplifier 40 could itself be used to excite speakers 95-97 rather than merely providing a triggering pulse to connect battery 92 into the circuit. Thus, it is desired that the present disclosure be considered as exemplary and limited only by the following claims.