Description:
This invention relates to apparatus for controlling an electrically operated device in response to the firing of a gun remote from the device.
In events such as foot races and swimming races, the firing of a starter gun is used to signal the start of the race. Electronic timers are now used in many such events to time the events. To produce accurate timing of the event the timer should be actuated simultaneously with firing of the gun.
A general object of the invention is to provide novel sound actuated apparatus for operatively interconnecting a starter gun and an electrically operated device remote from the gun in such a manner as to actuate the device simultaneously with firing of the gun.
More specifically, an object is to provide such novel apparatus which includes a microphone which may be detachably secured to a starter gun for detecting the sound of the firing of the gun, an electrical circuit connected to the microphone for producing a signal when the microphone detects the sound of the gun being fired, and an elongated flexible conductor for connecting the circuit to such an electrically operated device for transmitting the signal to the device. With such construction the starter gun may be positioned some distance from an electrically operated device, e.g. an electronic timer, and still produce actuation of the device substantially simultaneously with firing of the gun.
Yet another object is to produce such novel sound actuated apparatus which is easily connected to and disconnected from the gun. This is accomplished by providing a magnet for securing the microphone to the gun.
In long swimming races and other types of races requiring the participants to complete multiple laps of a pool or a track, it is often necessary for the starter to take the starter gun to another art of the pool, or track area, and fire the gun at the beginning of the last, or gun, lap to notify the participants that it is the last lap. Since the starter gun need not actuate the timer at the signalling of the gun lap it need not be connected to the timer.
Another object then is to provide novel sound actuated apparatus for connecting a starter gun to an electrically operated device, which apparatus is easily connected to and disconnected from the gun and device and is portable, whereby it may be carried easily by the starter as he moves from place-to-place in a contest area.
These and other objects and advantages will become more fully apparent as the following description is read in conjunction with the drawings, wherein:
FIG. 1 is a side elevation view of sound actuated apparatus according to the invention secured to a starter gun;
FIG. 2 is a view taken along the line 2--2 in FIG. 1; and
FIG. 3 is a schematic diagram of an electrical circuit in the apparatus.
Referring now to the drawings, and first specifically to FIG. 1, a starter gun 10 having an elongated barrel 12 is illustrated in dot-dash outline. Such gun has conventional firing mechanism, however it is constructed to fire only blank cartridges. Barrel 12 has no bore extending therethrough. At 14 is indicated a portion of an electronic timer, also referred to herein as an electrically operated device, having a jack 16 into which an electrical plug may be inserted.
At 20 is indicated generally apparatus constructed according to the invention. The apparatus includes a housing 22, which may be molded of material such as polyurethane. An elongated aperture 26, which has a substantially keyhole shape as viewed from an end, as seen in FIG. 2, is formed in housing 22. The aperture receives the muzzle of the gun barrel as shown in FIG. 1. Secured within housing 22, at the inner end of aperture 26, is a magnet 30 positioned to contact the barrel of the gun in the aperture. The magnet detachably holds the housing on the gun barrel.
Also secured within housing 22 are a microphone 34 and a circuit mounting board indicated generally at 36. The microphone is positioned in the housing to face generally in the direction of the gun when the housing is mounted on the barrel of he gun. An electric circuit 38 on board 36 is shown schematically in FIG. 3, and will be described in greater detail below.
An elongated, flexible, two-conductor cable 40 is secured adjacent one of its ends to housing 22 and has a plug 42 secured to its other end. Plug 42 has a center stem portion 44 and an outer stem portion 46 which are electrically insulated from each other. One conductor within cable 40 is connected to one of the stem portions and the other conductor within the cable is connected to the other stem portion. The stem portions of plug 42 are adapted to be inserted in jack 16 in the timer for detachably and operatively connecting the cable to the timer.
Referring now to FIG. 3, circuit 38 includes a pair of input terminals 50, 52 and a pair of output terminals 54, 56. Microphone 34, as illustrated schematically in FIG. 3, has output terminals connected to input terminals 50, 52.
The circuit includes three transistors 58, 60, and 62. Referring to transistor 58, its base is connected through a conductor 66 to terminal 50, and its emitter is connected through a conductor 68 to terminal 52. The collector of transistor 58 is connected to a conductor 70, one end of which is connected to the collector of transistor 60. The opposite end of conductor 70 is connected through a resistor 74 to output terminal 54 and through a resistor 76 to the base of transistor 62.
The emitter of transistor 60 is connected, through conductor 66 to terminal 50. The base of transistor 60 is connected through conductor 68, to input terminal 52, and through a conductor 78 and a capacitor 80 to terminal output 54. Conductor 78 is connected to output terminal 56 through a capacitor 82 and a rectifier 84 in parallel with each other.
Referring to transistor 62, its emitter is connected to output terminal 54 and its collector is connected to output terminal 56.
Referring still to FIG. 3, shown at 88, 90 inside of timer 14 are conductors which are connected to the usual two terminals of jack 16. Conductor 88 is connected through a resistor 92 to a suitable source of positive inside the timer, and conductor 90 is grounded. At 98, 100 are illustrated the two conductors of cable 40. The left ends of conductors 98, 100 in FIG. 3 are connected to output terminals 54, 56 of circuit 38, respectively. The right ends of the conductors are connected to the stem portions 44, 46, respectively, of plug 42. With plug 42 inserted in jack 16, conductive connections result between conductors 88, 98, and between conductors 90, 100.
Circuit 38 is so constructed that, with plug 42 inserted in jack 16 and a DC voltage supplied to the circuit, the sound of the firing of a starter gun adjacent microphone 34 will actuate the circuit to produce an electrical signal, or pulse, at terminals 54, 56. Explaining further, the firing of a gun adjacent microphone 34 produces oscillating pulses at the output side of the microphone which alternately turn transistors 58, 60 on and off, with one of the transistors being on while the other is off. Turning either one of these transistors on switches transistor 62 on, which produces a negative pulse, or signal, at the output terminals of the circuit. This pulse is transmitted to and is operable to actuate the timer. The circuit is such that ambient noises generally found in the area of an event to be controlled by the starter gun will be insufficient to produce a signal which will actuate the timer.
Explaining the operation of the apparatus of the invention, housing 22 is detachably connected to the muzzle of a starter gun by inserting the muzzle of the gun in the aperture in the housing. Magnet 30 holds the housing on the barrel of the gun. Plug 42 is inserted in jack 16 of the timer. When it is desired to start a race, the starter gun is fired. The sound of such firing is detected by microphone 34, which, in turn, actuates the electrical circuit connected thereto to produce an electrical signal, or pulse, at terminals 54, 56 of the circuit. This signal is conveyed by cable 40 to the timer, to actuate the timer.
After the timer has been actuated by the firing of the gun the plug may be removed from the timer and the housing disconnected from the barrel of the gun, whereby the gun may be used independently of the attachment. The attachment is small enough to be carried easily in a pocket or bag when it is disconnected from the gun and timer.
With the microphone, electrical circuit, and magnet being encased in polyurethane, or similar material, they are protected against rain, splashes from pools, and from damage due to jarring which might otherwise occur to such apparatus.
While a specific embodiment of the invention has been described herein, it should be apparent to those skilled in the art that variations and modifications are possible without departing from the spirit of the invention.