US2533765A - Selector apparatus for alarm signals - Google Patents

Description

Dec. 12, 1950 CHAUVEAU 2,533,765

SELECTOR APPARATUS FOR ALARM SIGNALS Filed Jan. 13, 1948 I 3 Sheets-Sheet 1 Dec. 12, 1950 CHAUVEAU 2,533,765

SELECTOR APPARATUS FOR ALARM SIGNALS Filed Jan. 15, 1948 3 Sheets-Sheet 2 I N V EN TOR.

6 Affair/vs Y I Dec. 12, 1950 CHAUVE'AU -SELECTOR APPARATUS FOR ALARM SIGNALS Fiied Jan. 15, 1948 5 Sheets-$heet 5 EMT R INVENTOK LOU/5 CHAUVEA u.

M W W Patented Dec. 12, 1950 SELECTOR APPARATUS FOR ALARM SIGNALS Louis (Jhauveau, Paris, France, assignor to Societe Francaise Radio-Electrique, a corporation of France Application January 13, 1948, Serial No. 1,976 In France December 10, 1946 Section 1, Public Law 690, August 8, 1946 Patent expires December 10, 1966 The present invention has for its object the provision of an apparatus for the preselection and transmission of alarm signals, and is intended for installation in ships, and to sound alarm bells when three dashes of 4 seconds dura-- tion separated by intervals of 1 second are received by the radio receiver which is assigned to this purpose. The dashes form part of the international alarm signal which comprises twelve dashes identical to those above, separated one from the other by 1 second intervals.

The alarm pre-selector transmitter constituted by the invention belongs to the class of preselector employing an intermittent contactor to activate relay networks, to step by step systems, or to all similar devices.

The said invention, taking into account the purpose of its applications, relates particularly to improvements whose main object is the provision of- 1. Economical consumption of the ships power supply.

2. The assurance of prompt starting of the intermittent contactor.

3. A greater degree of precision in the timing of signals.

4. Better control over the accuracy of working of the apparatus.

It comprises as well, a novel combination of elements and circuits resulting from the above 1 improvements.

Hereinafter is given by way of non-restrictive example, a description of one method of realizing the invention.

Three diagrams are supplied in connection with this description:

Fig. 1-general diagram of preselector.

Fig. 2-detail of intermittent contactor.

Fig. 3-general diagram of alarm signal transmitter.

When the apparatus Works in the role of an alarm signal preselector it must sound the alarm bells after the correct reception of three consecutive dashes of 4 seconds duration, and 1 second apart; it comprises: the dash timer; the timer of intervals between dashes; and dash recorder.

The dash timer comprises the intermittent contactor l, impulsing approximately every second and controlling the relay network T1-AT1, to T4AT4, in such a way that one group of these relays operates at each impulse. It is completed by a relay T5 responding to the fifth impulse by cutting off themain power supply when the dash is too long.

3 Claims. (Cl. 177-353) The interval timer is comprised by relay SIL which keeps up the main power supply a certain time after the reception of a correct dash, the supply being cut ofi" when the interval becomes too long.

The counter comprises a relay network E1-AE1 to E3-AE3, disposed in such a way that one group of these relays operates every time a correct dash is received, the last relay of this network promoting the action of the alarm bells.

The whole is completed by a control and power supply device whose role and function will be explained by the following.

Formerly, automatic alarm devices were powered by a battery of accumulators, but the modern technique is to power them by the ships power supply of 110 v. The elements composing the automatic alarm, the subject of this invention, are in general, standard telephone components, working on about v. It is therefore necessary to obtain their power supply through the intermediary of a voltage divider.

The voltage dividing circuit constituting one of the objects of the invention possesses the following characteristics. The voltage divider 2 is only in circuit when the signals received are of a certain duration, it is out of circuit for normal signals traflic. The voltage divider is subdivided into two parts 3 and 4, each part supplying a separate group of relays. (Circuit A, and circuit B.) By reason of this arrangement, the power consumption is at a minimum in the absence of alarm signals, and during the reception of these signals, the load is nearly balanced on each branch of the voltage divider. Therefore the voltage at the terminals of the relay circuits is nearly constant.

To this end, the apparatus comprises a starter relay DM normally energized in the absence of signals which, by means of its contact 5, cuts off the power supply to the voltage divider 2. A condenser of high capacity 6, shunts relay DM. The circuit of these elements is opened by contact l of relay RR, which receives all the signals from the communications receiver.

As a result of the presence of condenser 6, the release-timer of the relay DM is slowed by 0.4 second and is not de-energized under the influence of keyed signals. It is only de-energized by signals already possessing a certain length (0.3-0.4 second).

As soon as such a signal is received contact 5 is closed, and the voltage divider and circuits A and B are supplied with power. These circuits 3 are holding lines for the dash timer and the dash recorder, respectively.

The same sequence occurs from the beginning of the reception of the dash of an alarm signal.

The switching on of circuit A promotes the action of the intermittent contactor I by ener? gizing winding l5, which by way of its contact 8 controls the advance step by step of the relay network Ti-A'Tl to T4-AT4.

The synchronously oscillating relay I is constituted in the following manner (Figures 1 and 2) A flywheel 9 mounted on a shaft l8 to which is attached the spiral spring l l constitutes a balance wheel whose period is of the order of I second; that to say it makes two half oscillations per second. The shaft is supported in two bearings l2 and it. In order to promote starting up and to ensure the oscillation of the balance wheel, this wheel carries a magnetic portion It, which is attracted by the solenoid I5, the circuit of the latter being controlled by the contact 15, the latter contact working under the action of an arm I? integral with the shaft. The Whole is contrived in such a way that contact It is not closed by arm l! other than when the balance wheel is displaced in a clockwise direction, contact 15 being open when a movement takes place in the other direction. The wheel carries another arm l3 which controls contact 8 under the same conditions.

The shaft ill carries a flanged collar [9 with a rounded notch which engages the roller 26 carried by lever 21 which rotates about a shaft 25. A spring 22 pulls in this lever so that it maintains the balance wheel in its position of rest. The lever 2i can be displaced by the solenoid 23 so that it frees the balance wheel and allows it to go into action.

To obtain a good performance from such an intermittent contactor it is essential that the magnetic portion M, the solenoid I and contact [6, are in well defined positions in relation with each other.

They must not therefore be displaced from these positions. On the other hand contact 8 can be displaced in a slot 24-. It is therefore possible to obtain an advance or retard in relation to the balance movement by the positioning of the contact which ensures very precise adjustment of the measure of duration of a dash, as will be explained by the following.

This positioning of the moving contact 8 constitutes another feature of the invention.

Normally, in balance wheel devices of this kind, the whole is adjusted so that, when at repose, that is to say at the engagement of roller 20, the arm I! is a little behind contact IS; the spiral spring l i is then lightly Wound up in such a way that when unlocking takes place, the arm'll under the influence of the spiral spring makes contact l6, whence an impulse of current travels to the solenoid l5, and the system starts operating. However, this method of starting-up is precarious, the useful torque of the balance wheel being very small at the moment of starting-up.

Another feature ofthe invention lies in the association of a balance wheel with a torque relay LAN, these two elements being interconnected according to Fig. 1.

The relay LAN is disposed in such a way as to impart a strong current impulse to the solenoid l5 at the moment of unlocking, and up to the time of the establishment of contact I8; at this moment the relay LAN operates so as to include the contact [6 in the circuit of the maintaining solenoid I5. A resistance 25 allows control over the intensity of the impulses to obtain correct and continuous functioning of the oscillating relay.

The functioning of the apparatus in the role of preselector is then as follows: At the moment of the reception of a dash, circuit A is switched on with a lag 0.4 second, the unlocking relay 23 operates freeing the balance wheel of the oscillating relay; at the same time the maintaining solenoid I 5 is fed by way of contact 26 of relay LAN which is not yet energized. A strong impulse drags the balance wheel in a clockwise direction until arm ll closes contact It; this latter then feeds relay LAN which closes and locks on by its contact 21. Contact 26 connects the solenoid circuit 15 to the resistance 25 and contact l6.

It is thus evident that the balance wheel re-- ceives a first and strong impulse, which ensures prompt starting up and that it maintains its oscillation under the action of suitably regulated impulses transmitted by contact 46.

At each oscillation contact 8 is closed. At the first oscillation its closing takes place about 0.1

second after the commencement of oscillation of the balance wheel. It controls the circuit of the relay network T1T4 together with that of the auxiliaries AT1-AT4 in such a way that one'set of relays is energized at each impulse; this constitutes a step by step system of known type.

In practice relay T4 wil be energized by contact 8 during the fourth oscillation of the intermittent contactor.

International regulations in force stipulate that a certain degree of precision be ensured in the measurement of a dash by an automatic alarm preselector.

The correct dash should last between 3.5-4.5 seconds to the nearest /10 second. It is therefore necessary that the closing of contact 28 of T4, which characterizes the end of the correct dash, is effected at the end of an accurately timed period. Now automatic alarm apparatus, mass produced, can present many variables between components such as: the time constant of relay DM and its associated condenser 6, the frequency of intermittent contactor, the make and break times of different relays etc.

The position of contact 8 of the intermittent contactor being moveable, allows of correction of these variables. In practice, with the apparatus in working condition it suiilces to move contact 8 in its slot 24 (Fig. 2) one, way or another, in order to obtain the closing of contact 28 with the required degree Of accuracy exactly 3.5 seconds after the beginning .of the dash. As has been said earlier, this constitutes one of the features of the invention.

Thus, as has been. shown, each dash of correct length is conveyed by the closing of contact 28 of relay T4. This contact controls a network of counter relays, E1TAE1 to. E3.AE3, connected in the known manner by step-by-step circuits.

It therefore follows that at the end of the reception of three consecutive correct dashes of an alarm signal, the contact 29 of relay AE3 is closed. It promotes the action of the alarm bells as will now be explained.

As can be seen by the foregoing explanation, the action of T4. takes place atv the fourth impulse of the intermittent contactor which cor.- responds to a dash of 3.5 seconds, duration. At the fifth impulse of the contactor, the impulse made by contact 8 is diverted by contact 30 of relay AT4 to relay T5 which is an excess time relay. As a result, should this fifth-impulse ocour, relay Ts operates and remains closed; this occurs when the dash lasts 4.5 seconds. T5 by its contact 3| cuts oil the general power supply and maintains this condition during the whole of a dash which exceeds 4.5 seconds. The counter relay group is then put at rest. A dash that is too long is thus without efiect.

During the intervals of time separating the dashes of the signal, the relay DM cuts ofi the power as long as the silence does not exceed a certain time, in practice 1.5 seconds. 7

To this end, the relay SIL is fed by contact 32 of AT; which is closed immediately after the fourth impulse. (That is to say, 3.5 seconds after the reception of the signal.) This relay SIL is shunted by a condenser 33 and a resistance 3 the whole forming a slow-releasing relay. It follows that at the end of a correct dash, the relay DM opens its contacts 35 and 5, the first contact cutting the supply to the network T1T4 and the oscillating relay, which all come to rest; the second contact opens, but the make contact of the slow-releasing relay SIL remains closed (maximum delay 1.5 seconds) so that the voltage divider 2 is still connected to the source during the time of a correct silence. By way oi security, at the beginning of the next dash, the relay ATi by its contact 36, short circuits the condenser 33 to ensure, if necessary, its discharge. In addition, the relay ATs by its contact 3i promotes, arter the third impulse, the de-energizing or" T1AT1, and of TzATz, which will allow a new charge to the condenser at the fourth impulse.

In the event of the reception of a dash that is too short, that is to say or" duration less than 3.5 seconds, relays T4AT4 do not operate; the group SIL with its condenser 33 and resistance 34 is not energized, so that at the end of the dash, DM, by way of its contact 5 cuts the general supply, whence the de-energizing Of the whole apparatus, this dash thus has no effect.

The combination and the disposition of the relays SIL, DM, and the difierent circuits and contacts which have just been described, constitute another main feature of the invention.

By way of safety device the pre-seleotor comprises an alarm bell relay SN disposed in a special manner, constituting another feature or" the invention.

All the elements of the pre-selector described above are powered by a circuit specially suited to the power supply of a ship (circuit SP). The relay SN is powered by another auxiliary circuit AX totally remote from the former power supply.

The circuit of relay SN comprises a resistance 38. When the apparatus is switched on the relay SN is energized by pressing the button B. SN locks on by its contact 39. SN can be short circuited either by the contact 29, after the reception of a correct signal, or by contact All of the no volts relay RMV which is in series with the valve filament circuit of the radio receiver. When SN comes to rest its two contacts each feed an alarm bell, one in the general circuit, the other in the auxiliary circuit. As a result 1. The two circuits being supplied with power, the two bells go into action after the reception of the correct signal, until the button B is again pressed.

2. In the event of failure of the general circuit, the bell in the auxiliary circuit operates.

3. In the event of failure of the auxiliary circuit the bell in the general circuit operates.

While I have described my invention in one of its preferred embodiments I realize that modifications in detail may be made and I desire that it be understood that no limitations upon my invention are intended other than may be imposed by the scope of the appended claims.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

1. In an apparatus for receiving and selecting radiotelegraphic signals composed of a series of dashes which range in duration from a given standard minimum to another standard maximum and are separated from one another by time intervals of a predetermined maximum duration, 2. receiver, a selector connected with said receiver, a direct-current supply feeding the selector, a dash timer fed from said supplyfor a part of each dash, a timer of intervals between dashes cooperating with the dash timer, and a recorder of correct dashes cooperating with the two said timers and actuating at least one warning device at the end of the reception of each correct signal; the dash timer comprising a momentum device with electrically sustained oscillations, a chain of interconnected relay devices, means for the energizing of these relay devices, these means being impulsively controlled by the momentum device at its own rhythm of oscillation during the operation of the dash timer and progressively connecting a holding line to the relays of the chain, at the rate of a further relay per oscillation period, a starting relay controlled by the output circuitof the receiver, means associated with said relay and connecting the said holding line and the momentum device to the supply with a delay less than one second after the reception of each dash, the same means being adapted to deenergize the holding line and momentum device at the end of a dash longer than the above-mentioned operation delay and shorter than the standard maximum, a time excess relay normally deenergized cooperating with the interval timer and controlled by the last relay of the dash timer so as to restore the selector to rest condition when a dash is longer than the standard maximum; the timer of intervals between dashes comprising a relay device connected to the supply through the last relay of the dash timer and having a release time delay greater than the maximum standard length of an interval, this relay device cooperating on the one hand with the starting relay so as to restore to rest condition the whole selector when the duration or" an interval following a correct dash exceeds the fixed maximum, on the other hand with the time excess relay so as to hold it energized aiter a too long dash during the above-mentioned release-time delay; the recorder of correct dashes comprising a chain of interconnected relays, whose number equals the number of correct dashes required to form a correct signal, means for the energizing of these relays, controlled by the last relay of the dash timer and enabling a further relay to be connected to the supply at the end of each correct dash separated from the previous one by a correct interval, and means for the actuation of at least one warning device, controlled by the last relay of the recorder.

2. In an apparatus for receiving and selecting radiotelegraphic signals composed of three dashes which range in duration from 3.5 seconds to 4.5 seconds and are separated from one another by time intervals not exceeding one second, a receiver, a selector connected with the receiver, a direct-current supply feeding the selector, a dash estates 7 timer fed from said simply for a part of each dash, a timer of intervals between dashes cooperating with the dash timer and a recorder of correct dashes cooperating with the two said timers and actuating at least one alarm device at the end of the reception of each correct signal; the dash timer comprising a balance wheel with electrically sustained oscillations, the period of'which is substantially equal to one second, a chain of four interconnected relays cooperating with the balance wheel device by way or energizing means, which are impulsively controlled by this device at its own rhythm of oscillation during the operation of the dash timer, these means progressively connecting a holding line to the said relays at the rate of a further relay per period, a socalled starting relay, controlled by the output circuit of the receiver, means associated with that relay and connecting the said holding line and the balance wheel device to the supply with a delay of about 0.4 second after the reception of each dash, the same means being adapted to deenergize the holding line and balance wheel device at the end of a dash longer than about 0.4 second and shorter than 4.5 seconds, a time excess relay the one hand with the starting relay so as to restore to rest condition therwhole selector when the duration of an interval following a correct dash is substantially greater than one second, on the other hand with the time excess relay so as to hold it energized after a too long dash during the above-mentioned release-time delay; the recorder of correct dashes comprising a chain of three interconnected relays, means for the ener gizing of these relays, controlled by the fourth relay of the dash timer and enabling a further relay to be connected to the supply at the end of each correct dash, separated from the previous oneby a correct interval, and other means for the actuation of at least one alarm device, controlled by the third relay of the recorder.

3. In an apparatus as set forth in claim '1 wherein the momentum device consists of a bal--- ance Wheel, electromechanical means for releas ing the latter, these means being permanently connected to the holding line of the dash timer relays, adjustable means adapted to apply to this wheel an electromagnetic couple at the beginning of every oscillation, these means being con nected to the holding line through a fixed contact periodically closed by the said Wheel and being able to diminish the applied couple adjustably after the first wheel oscillation; the energizing means for the relays oi the dash timer, being connected with said holding line through a con-'- tact periodically closed by the balance wheel for a very short time, the position of this contact being adjustable along a circle coaxial with the balance wheel.

LOUIS CHAUVEAUi REFERENCES CITED The following references are of record'in the file of this patent:

UNITED STATES PATENTS Num er Name Date 1,585,313 Tupper l l.- May 18, 1926 1,655,689 Chauveau Jan. 10, 1928 1,867,209 Chauveau l -l July 12, 1932 1,967,396 Chauveau a r .l July 24, 1934' FOREIGN PATENTS Number Country fiate 7 535,956 Germany May 18, 1936

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