US2250834A - Radio alarm system - Google Patents

Description

July 29,1941; J. 0. HOWTON 2,250,834

RADIO ALARM SYSTEM Filed Jan. 12, 1938 4 Sheets-Sheet l Q l'l l'm l'l l l l l w I vent J0 .BQwion QMMwA M m Attorneys y 29, 1941- J. o. H-OWTON 2,250,834

RADIO ALARM SYSTEM Filed Jan, 12, 1938 4 Sheets-Sheet 2 I I I I I I I a a N i I I z h R a i I I I I 5: LI.. i I I I I I I I I I I u I 5 Lu? I. l Inventor J ffawfon By 2mm Attorneys Jill 29, 1941. J. o. HOWTON 4 RADIO, ALARM SYSTEM Filed Jan. 12, 1958 4 Sheets-Sheet 3 Attorneys 29,1941- J. o. HOWTON 2,250,834

' RADIO ALARM SYSTEM I Filed Jan. 12, 1938 4 Sheets-Sheet 4 Inventor fizwaofih wamvm Attorneys Patented July 29, 1941 RADIO ALARM SYSTEM James Orllowton, Freewater, reg., asslgnor to Howton Radio Alarm Company, Seattle, Wash.

Application January 12, 1938, Serial No. 184,713

2 Claims.

This invention relates to alarm systems and adjuncts thereof and particularly to radio alarm systems adapted to broadcast automatically on police and fire bands so that these departments will be directly and appropriately advised of emergency conditions.

As illustrative of the invention I have shown two embodiments thereof in the accompanying drawings with reference to which description will be made in order that the principles underlying the invention may be clearly understood. According to the first embodiment, distinguishable code messages may be broadcast for direct receptionby the appropriate department. According to the second embodiment a sound record is utilized for the voice broadcast of fire and/or burglar alarms.

In the drawings: I

Figures 1 and 1a, taken together, constitute a diagrammatic representation of the first embodiment of the invention designed to broadcast in code for either burglary or fire.

Figure 2 is a diagrammatic representation of the second embodiment designed to broadcast voice alarms in case of fire and/or burglary.

Figure 3 is an elevational view of a fire alarm circuit relay which appears diagrammatically in Figure la.

Figure 4 is an elevational view of a burglar alarm circuit relay, also appearing diagrammatically in Figure 1a.

Figure 5 is a side elevation of code keying mechanism and driving motor shown diagrammatically in Figure 1.

Figure 6 is a front face view of the mechanism of Figure 5.

Figure 7 is a rear view of mechanism of Figure 5, and

antenna 56 through tuning condenser 51. In-

' ductance 55 is adjustable.

The above described transmitting circuit receives both filament and plate supply voltage from f alternating current transformerfl, secondary coil from resistor 29 which may be tapped for vari- Figure 8 is a face view of a sound record disc nates a crystal oscillatorwhich drives the grid of a tube 3| of which the plate drives inductance 43, the latter being tuned for resonance by variable condenser 42. Inductance 43 drives grid 48 of a tube 46, the final amplifier, through condenser 44, capacitively coupling tube 46 to the first crystal amplifier tube 3|. The plate circuit, fed by plate 52 of tube 45, drives the variable inductance 53 of a radio frequency transformer, 53, 55, inductance 53 being tuned by a variable condenser 52. The antenna and ground circuits are inductively fed to inductance 55 and receive energy from this inductance which is fed into able voltages. Transformer 9 is driven by a rotary converter or motor generator I which in turn is driven by a direct current battery 6. The function of motor generator I is to convert the energy from direct toalternatlng current. As here shown, the battery 6 is in connection with a trickle charger 6a.

In Figure 1a reference numeral I designates a burglar alarm circuit in connection with a. set of dry cells 6b. The circuit l is adapted to be closed when the various doors, windows and so forth, interposed in series therein are closed. The door and window switches may be-of any standard form and one is indicated by way of example at 60. The coil of a relay 2 is included in circuit I and when the coil is energized, which is the condition contemplatedin Figure 1a, contacts 3a of the relay are closed and contacts 3 are open. The armature of the relay is indicated at 3b. With contacts 311 closed and all other devices of the burglar circuit in protective condition, the burglar circuit is in its normal closed condition.

Contacts 3 are connected by wires 4 and 5 through battery 6 and a normally closed thermal switch 8 with the motor terminals of unit 1. A motor I2 is adapted to be driven from converter 1 through wires l3 and I4. Mounted on the shaft of motor I 2 in insulated relation to the motor, are a pair of conductive discs l5 and I 512 of which the former has a series of peripheral teeth [6 formed at intervals, each series of teeth being designed in accordance with a predetermined code. Disc l5a is formed as an eccentric and both it and disc l5 are in connection through wire [5b with the grid of transmitter tube 3!. A contact I! is disposed for engagement by the teeth It and is connected by a wire Ila and a wire a, to be hereinafter described, with a common conductor lie, so that a circuit is completed between conductor Ho and filament 32 of the tube 3|, oscillations being thus allowed to pass through this tube.

Reference numeral 63, Figure 1a, designates a fire alarm circuit in connection with battery 6b and having interposed therein a normally open thermostat 64. Also included 'inthe fire alarm circuit is a relay 65 which, through an armature 65a, controls the contacts 68 and 69. The fire alarm circuit ordinarily follows the burglar alarm circuit to afford protection coextensive with the latter and, of course, a suitable number of thermostats 64 may be provided in parallel. With the fire circuit open, contacts 68 and B9 are also open, since the coil of relay 65 is not energized.

Contacts 69 are in connection with wires 4 and 5 through wires 4b and 5b. Contacts 68 are in connection through wires 5a and 50 with line He and the contact 61 respectively, Figure 1, contact 61 being arranged to wipe the edge of disc l5a throughout substantially half a revolution of the latter.

The operation is as follows:

Upon breaking the burglar circuit I and consequent de-energization of the winding of relay 2, contacts 3a are broken, making the burglar control circuit inoperative until relay 2 is manually reset. Contacts 3 are closed so that battery 6 is placed in connection with the motor of unit I through wires 4 and 5 and thermal switch 8. The generator of unit I energizes the transformer 9, thus placing the transmitter in operation, and also starts motor i2 through wires l3 and i4 so that the keying members I5 and [5a are totated. Contact i1 is then periodically engaged by the points 16 on the periphery of interrupter I5 so that a code signal, which is a burglar signal, is broadcast.

The heat of tube 45 opensthermalswitchB after a desired time of operation so that operation of the apparatus is arrested.

In case of fire,theclosing ofcircuit 63 by thermal switch 6 causes the coil of relay 65 to be energized, thus closing contacts 68 and 69. Since contacts 59 are in connection with wires 4 and 5, a driving circuit for the motor of unit I is established as before. The closing of contacts 68 causes contact 61 and disc l5a to be connected in parallel with contact I! and disc I5 so that when disc l5a engages contact 61 a long dash is added to or introduced into the signal previously described for burglary, thus changing the character of the signal and denoting fire, thermal switch 8 functioning to stop the apparatus as before described.

From the above it will be evident that intelligible and distinguishable signals are produced by the alarm message producing apparatus in case of burglary and in case of fire.

Referring now to Figure 2, reference numeral 28 designates a crystal oscillator which drives an oscillator tube 41 through a stabilizing resistor 41a. The plate of tube- 4! drives inductance 41b which is tuned to resonance by variable condenser 41.0. This circuit capacitively drives the grid of a tube 45' through a capacity 41d which in turn drives the plate of tube 45' and inductance 45a which is tuned by a variable capacity 45b. This circuit capacitively drives tube l5 through capacity 45c, tube l5 being the final amplifier which is modulated by tube 41 through transformer 39', the secondary of which impinges the audio frequencies through coil 45d onto the grid side of tube 15', thus isolating the circuit from the tube 45' through capacity 45c.

Battery 39a furnishes necessary bias for the tube of grid I 5. Tube 41" is driven through transformer 38' by audio frequency current from tube 56 which in turn is supplied with audio frequency energy through transformer 56a from the message producing means to be hereinafter described.

Rectifier I3 delivers plate supply to the final radio frequency amplifier tube i5 through a filter 50', conductors 50a and 50b. A secondary coil of the transformer [2' also furnishes energy to filament of tube l5.

A rectifier 83 supplies plate current to all other tubes in the transmitter through a filter 83' and the secondary of a transformer 2| supplies the filament current for these tubes.

Transformers [2 and 2! receive alternating current from a rotary converter or motor generator H, and a motor for driving a sound record turntable 33 also receives alternating current from unit ll through wires connected to the leads I9 and 20'. A direct current battery l0 supplies current to the motor of unit II and is in turn kept at full charge by a trickle charger 5|.

The'burglar alarm circuit I includes one or more switches such as indicated at in: which are closed when the circuit is in protective condition and in this circumstance the coil of relay 3' is energized by battery 2' so that contacts 4 are closed and contacts I1, 29' and 28a are open. When circuit I" is broken by an unauthorized person entering the protected premises, contacts 4' are opened and the burglar circuit remains open until relay 3' is reset. Contacts I1, 29' and 29a are closed. Contacts l'l in closing, close a battery circuit through wires 8 and 9 and a stop switch 44' adjacent motor turntable 33', thus starting motor generator Ii and causing the transmitter to function, also starting the turntable motor through wires l9 and 20. Contacts 29' and 29a in closing, close a circuit from a pickup or reproducer head 32' through wires 30', 3|, 34 and 35' so that audio frequency energy is fed into the primary of transformer 56a and a burglar alarm message is thus placed on the air, assuming the sound record disc, to be hereinafter described, is on the turntable 33'.

In case thermostat 4i of fire alarm system 40 closes, as upon the occurrence of fire in the protected premises, the coil of relay 42 receives energization from battery 40a and the relay contacts 43', 41' and 46' are closed. Contact 43' in closing, closes a battery supply circuit through the stop switch 44', thus starting motor generator I l' and placing the transmitter in operation as before. Contacts 48' and 41' feed audio frequency energy from a second reproducer head 48 to the primary of transformer 550., thus causing a fire alarm message to'be transmitted, assuming the sound record to be in place on the table 33'.

The sound record may vary as to form but essentially comprises a sound track or tracks engageable by the needles of the pick-up heads 32 and 48' in such a manner that intelligible and distinguishable signals can be broadcast. The sound record disc 60 shown in Figure 8 comprises inner and outer sound tracks GI and 62, the former carrying the fire alarm message and the latter the b' glar message. With the apparatus set for operat the record 60 is placed on turntable 33' with the head 32 at the beginning of the sound track or band 62 and with the head 48' at the beginning of the sound track or band 6|, so that in case of disturbance of either the fire or burglar circuits or both, the reproducing head or heads will immediately affect transswitch 44 regardless of whether a burglar or fire I alarm or both,'has been broadcast.

Each sound track is made with alternate active and blank track sections. That is to say, in cutting the sound track 62, for example, a fire message giving the location of the premises is impressed, a suitable pause follows, and then the message is repeated, and so on. The same applies to sound track 6|. In case of both fire and burglary on the same premises, both of the pick-up heads will be placed in operative association with the transformer 56a so that both messages will be broadcast. However, due to the intervals between the messages picked up from the two tracks, one message will frequently be broadcast in the interval of the other and vice versa, so that two intelligible and distinguishable messages, one for fire and one for burglary will be alternately broadcast. The embodiment of Figure 2 is particularly important by reason of the fact that it is capable of broadcasting either a burglar alarm or a fire alarm or both.

It will be understood that the described embodiments are illustrative and not restrictive of the invention and that various changes in the form and arrangement of the apparatus are ,possible without departure from the scope of the following'claims.

I claim:

1. An alarm system comprising a, transmitter, an automatic alarm message producing means in connection with said message producing transmitter, a protective circuit in connection with said message producing means, and control means responsive to said circuit between said. circuit and said message producing means to place said message producing means in operation when said circuit is disturbed, said message producing means comprising code signalling means including a conductive wheel having peripherally spaced groups of teeth of which each group is arranged in accordance with a predetermined code and including also a contactor for cooperating with said teeth, means for driving said wheel, the operation of last-named means being governed by said control means, a normally open circuit in parallel with said wheel and contactor, and means for closing said circuit whereby to supersede a portion of the code signal which circuit in connection with said message producing means, and control means responsive to said circuit between said circuit and said message producing means to place said message producing means in operation when said circuit is disturbed, said message producing means comprising code signalling means including a conductive Wheel having peripherally spaced groups of teeth of which each group is arranged in accordance with a predetermined code and including also a'contactor for cooperating with said teeth, means for driving said wheel, the operation of said lastnamed means being governed by said control means, a normally open circuit in parallel with said wheel and contactor, and means for closing said circuit whereby to supersede a portion of the code signal which would otherwise be produced. said normally open circuit being also governed by said control means, said circuit closing means including a rotary member driven concomitantly with the code wheel.

JAMES O. HOWTON.

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