US3638213A

US3638213A - Electrical alarm system

Info

Publication number: US3638213A
Application number: US885733A
Authority: US
Inventors: Glenn C Dagle
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-12-17
Filing date: 1969-12-17
Publication date: 1972-01-25
Anticipated expiration: 1989-01-25

Abstract

The electrical alarm system is particularly adapted for use in connection with banks to sound an alarm during a bank robbery. The alarm system includes a photocell device which is positioned beneath a stack of treasury bills located in a money compartment at a teller''s cage. Removal of the entire stack of bills by a teller in response to the demand of a bank robber exposes the photocell to light rays whereupon the photocell is energized and triggers an alarm system to apprise security forces of the existence of the emergency.

Description

United States Patent Dagle 1451 Jan. 25, 1972 54] ELECTRICAL ALARM SYSTEM 3,076,897 2/1963 ....340/228 5 3,432,842 3/1969 ..340/280 [72] Inventor: Glenn C. Dagle, 29844 Penme Road, 3,467,771 9/1969 340/280 x Dearborh He1ghtS,M1h-48125 3,407,400 10/1968 Lurie ..340/280 22 Filed: Dec. 17, 1969 Przmary ExaminerJohn W. Caldwell PP 885,733 Assistant Examiner-Scott F. Partridge Attorney-Whittemore, Hulbert & Belknap [52] U.S. Cl ..340/280, 250/209, 317/124 51 1111. C1. ..G08b 13/18 [571 ABSTRACT Field of Search 223 The electrical alarm system is particularly adapted for use in 7/12 307/117 connection with banks to sound an alarm during a bank robbery. The alarm system includes a photocell device which is [56] References Cited positioned beneath a stack of treasury bills located in a money compartment at a tellers cage. Removal of the entire stack of UNITED STATES PATENTS bills by a teller in response to the demand of a bank robber ex- 3,300,770 1 1967 Brousseau et al ..340/280 Poses the photocell to light y whereupon the photocell is 3,307,848 3/1967 Bracken et 81"" energized and triggers an alarm system to apprise security 3,089,065 5/1963 Worden ..317/124 x forces of the existence of the emergencyl,494,656 5/1924 Wherland ..200/52 J 9 Cl 8 D 2,964,685 12/1960 Raymond ....317/124 3,428,813 2/1969 Hofmeister et al. ..250/209 P I 62 70 1 L3 .r 5247/0/1 i i I 42 dz 1 64 E i i J{ J 6a 66 /.9c9 6462. LJ&

82 P54 97" 57A r/o/v l W 76 i 78 20 I A doc 73 @JO L 5017/04 2 f l we I V l FIG.2 /Z6 A28 /04 A32 An 7 /0 9 4 4i @& /34 A22 A18 meal/7' 435 PATENTED JAN25 I872 SHEET 2 8f FIG.3

INVENTOR.

4 44 177 ATfiR N EYS ELECTRICAL ALARM SYSTEM BACKGROUND OF THE INVENTION Armed robberies of places of business, particularly banks, have become increasingly severe in recent years. Various alarm systems have been proposed in the past for actuation by a bank teller during a robbery. However, the majority of such systems have required positive action on the part of the teller, such as depression of a switch, in order to actuate the alarm. Bank robbers, who have become increasingly sophisticated, demand that the teller do nothing excepting as instructed. Any movement of the teller which deviates from the robbers instructions, such as movement to depress a switch, seriously endangers the tellers life. As a consequence of this danger, banks have increasingly disapproved of alarm systems which require positive action on the part of the teller.

Various alarm systems have been proposed which do not require positive action on the part of the teller. However, such systems have basically worked with mechanical switching devices. Such mechanical switching devices are somewhat unreliable because it is difficult to provide a mechanical switching system sensitive enough to always respond to the slight pressures resulting from the presence or absence of a lightweight treasury bill. Mechanical systems also tend to become less reliable after being installed for long periods of time because of the accumulation of dust and the like in the mechanical working parts.

In accordance with the present invention, an electrical system is provided in which the basic actuating device is a photocell. A photocell is not subject to inoperativeness as a result of the effects of normal ambient conditions such as dust and the like, and may be triggered by light rays thus obviating the problem of pressure sensitivity. The invention also includes a testing technique whereby the operativeness of the entire alarm system may be assured at thebeginning of each business day.

SUMMARY OF THE INVENTION The electrical alarm system comprises at least one electric photocell which is mounted in a position for normal coverage by an article of value. A source of light is positioned to impinge light rays onto the photocell and energize the photocell to a conducting state when the photocell is uncovered. A first electrical relay is provided. This relay has a coil connected in series with the photocell. A source of electric power is connected across the photocell and relay coil. The first relay has a set of normally open contacts. A second electrical relay has a coil which is connected in series with the contacts of the first relay and across the source of electric power. An electrical alarm circuit is provided. The second relay has a set of normally open contacts connected in said alarm circuit and adapted to energize the alarm circuit upon closure thereof. Uncovering of the photocell will cause energization of the first relay coil with resultant closure of its contacts. Closure of the contacts of the first relay coil will cause energization of the coil of the second relay with resultant closure of its contacts and energization of the alarm circuit.

IN THE DRAWINGS FIG. 1 is an electrical schematic view of one embodiment of the electrical alarm system of the present invention;

FIG. 2 is an electrical schematic view of a circuit associated with the circuit of FIG. 1;

FIG. 3 is a plan view of a plurality of bank tellers cages in which circuitry of the present invention is incorporated;

FIG. 4 is a view in perspective of a photocell assembly utilized in connection with the invention;

FIG. 5 is a sectional view of a cash drawer pocket in which the photocell assembly of FIG. 4 is mounted;

FIG. 6 is a front elevational view with parts broken away of a monitor used in connection with the invention;

FIG. 7 is an exploded view in perspective with portions broken away of the monitor of FIG. 6; and

FIG. 8 is an electrical circuit view illustrating a modified version of the FIG. I circuitry.

FIGS. 1 and 2 illustrate electric circuits 10, I2, portions of which are physically located in the bank tellers cages 14 shown in FIG. 3 and in a distant monitor 16 shown in FIG. 6. The portions of the circuit located in the tellers cages I4 are enclosed in the dotted rectangles I8, 20, 22 of FIG. I. The remaining circuitry is provided in the monitor 16.

Referring to FIG. I, it will be noted that the source of electrical power for the circuit 10 includes a stepdown transformer 24. The primary winding 26 is connected across a source of AC power 28 which may be the usual conventional l 15 volt commercial supply. The secondary winding 30 is connected in main power line 32. The turns ratio may be such as to result in a stepdown voltage of 24 volts. A fuse 34 is provided in power line 32 to safeguard the circuit. The fuse, as will be noted in FIG. 6, is physically located in the monitor 16 and may be replaced at this point. A pair of

leads

36, 38 extend from the lead 32. Individual circuits for each station are connected in parallel between the

leads

36, 38. The number of stations is determined by the need at the particular installation. The number may be increased or decreased as desired. Representatively, FIG. 1 illustrates an installation wherein l4 stations are provided, this number corresponding to the number of tellers cages in a particular bank. Only station No. 1 will be described in detail, it being appreciated that the other stations repeat the circuitry of the first station.

A lead 40 extends from the lead 36 to a junction 42. Three leads, 44, 46, 48 extend from the junction 42 in parallel. A

photocell

50, 52 is provided in each of the

leads

46, 48. In operation of the circuit, whenever one of the

photocells

50, 52 conducts, an alarm system is energized. The

leads

46, 48 are connected in parallel on the other side of

photocells

50, 52 by means of a lead 56. The lead 56 also extends into connection with a lead 58 extending between

leads

36, 38.

The coil 64 of a relay is provided in a lead 60 which extends from the junction 62 into connection with lead 38. One set of contacts 64a of the relay are provided in the lead 58 between a manual reset switch 66 and the connection of lead 56. The relay has a second set of contacts 64b which are provided in the alarm circuit as will be later described. An alarm lamp 68, preferably red, is provided in the lead 58 between the juncture of lead 56 and the lead 38. Another lamp 70, preferably amber, is provided in the lead 44. The function of the lamp 70 is to indicate operability of the circuit. A manually operable on-off switch 72 is provided in lead 40 to permit the teller to energize and deenergize his particular station.

Station No. 2 includes

photocells

74, 76, relay coil 78, contact 78a, red lamp 80, and switch 84 arranged in the same manner as above described. The second set of contacts 78bof coil 78 are arranged in the alarm circuit. Similarly, station No. 14 includes photocells 86, 88, relay coil 90, coil contacts a, red lamp 92, amber lamp 94 and switch 96. The second set of contacts 90b of coil 90 are located in the alarm circuit.

A common lead 98 extends from the lead 58 between reset switch 66 and relay contacts 64a into connection with leads 100, 102 and all intermediate leads so that the single reset switch is operative to control the entire circuit. As will be noted in FIG. 6, the reset switch 66 is conveniently located on the front panel of the monitor 16. Similarly, the

lamps

68, 70, 80, 82, 92, 94 are located on the front face of panel 16, the red lamps being in the upper line and the amber lamps being in the lower line. The proper numbers are provided above each pair of lamps to identify each station.

The power leads 36, 38 also supply power to the circuitry which initiates the alarm signal. A pair of leads I04, 106, extend between the

leads

36, 38. A set of contacts 108, of a double-throw four-pole key-operated switch 1 12 are provided in leads I04, 106. A third set of contacts 114 are provided in a lead 116 which is directly connected by leads I18, 120 to a distant alarm circuit 121. A fourth set of contacts 122 are provided in a lead 124 which is dead ended, the fourth set of contacts not being used in this circuit.

As will be noted, in one position of the switch 112, termed OFF" position, the switch arm 126 closes the contacts 110 while the

other switch arms

128, 130 open the contacts 108, 114. A test lamp 132, preferably green, is provided in lead 104. Another lamp 134, preferably red, indicating that the circuitry is in the energized condition, is provided in lead 106. It will be noted in FIG. 6 that the

lamps

132, 134 are placed in side-by-side relationship on the front panel of the monitor 16 directly above the switch 112. The green lamp is labeled OFF, and the red lamp is labeled ON." The switch 112 is labeled ALARM." As will be noted, the key slot 136 is oriented to point to either the OFF lamp 132 or the ON" lamp 134 to give a visual indication to the operator and tell him what condition the monitor is supposed to be in.

A lead 138 extends from the lead 106 from a point between the switch contacts 108 and the lamp 134. A second lead 140 extends in parallel relationship to the lead 138. Leads 142, 144, 146 extend in parallel between the leads 138, 140. The contacts 64b, 78b and 9012 are provided in leads 142, 144, 146. Parallel leads 148, 150 extend from the lead 140 into connection with the lead 38. The coil 152 of an alarm relay is provided in lead 148. The coil 152 has a set of contacts 152a which are provided in the lead 116. The timing structure 154 of a timer is provided in the lead 150. The timer has a set of normally closed contacts 154a in the lead 116. It will be noted that all of the contacts of the various relays are normally open, the contacts 154a being the only normally closed set of contacts in the circuit. The relay coil 152 has a second set of contacts 15217 which are provided in a lead 156, FIG. 2, which is connected to a local alarm circuit 157 in the building in which the circuitry is installed.

The timer structure 154 may be any conventional timer, such as a timer with a heater 154C and bimetal strip 154b which deforms after the heater is operated a specified length of time to open the contacts 154a.

Before explaining the operation of the electrical circuitry, the physical structure associated therewith should first be understood. Referring to FIGS. 3, 4 and 5, it will be noted that the structures in which the tellers are arranged include the usual

compartmented enclosures

158, 160, 162 which have

windows

164, 166, 168 in the front walls thereof for servicing customers. A

door

170, 172, 174 is provided in the backwall for ingress and egress of the teller, a

shelf structure

176, 178, 179 surrounds the tellers cage. A

cash drawer

180, 182, 184 is positioned on the shelf adjacent the teller for storage of money. Such drawers are normally divided into a number of different compartments of treasury bill size, these compartments being used to store bills of a particular denomination. Two

photocell assemblies

186, 188, 190, 192, 194, 196 are provided in the cash drawers, each assembly occupying one compartments or pocket of the drawer and resting on the bottom thereof as shown in FIG. 5. The denomination of bills stored in the pocket may be as desired, however, preferably the denomination is of the type most frequently called for by bank robbers, such as S-dollar bills and lO-dollar bills, or dollar bills and -dollar bills.

Each photocell assembly, illustratively, the assembly 186, comprises a rectangular block 198 in the general shape of a treasury bill. The block 198 is, however, slightly smaller than a bill, about one-eighth inch all around, to permit ready removal of the last bill of the stack 200, as illustrated in FIG. 5. Additionally, the block is about one-half inch smaller all around than the interior dimensions of the compartment 202 so that the teller can insert his fingers in between the ends of the block and the interior surface of the compartment.

The block 198 may be fabricated of any suitable material, such as plastic. A layer of material 204 may be adhered to the top surface of the block 198 to simulate the appearance of wood so that it will not be obvious to the bank robber that there is an electronic device at the bottom of the compartment 202. The photocell 50 projects through the layer 204 to permit impingement of light thereon. An opening 206 is provided in the block 198 for reception of the body of the photocell 50.

Elongated openings

208, 210 are drilled longitudinally of the block 198 into communication with the opening 206 for reception of a cable 212 which encompasses the photocell leads. The unused opening permits connection to thephotocell from either end of the block. Alternate to the use of plastic material for fabrication of the block 198, wood, metal or any desired material may be used.

The cages which contain the cash drawers are positioned beneath a source of light 214, diagrammatically illustrated in FIG. 5, for energization of the photocell when the last bill has been removed from the money compartment. In practice, the source of light is the normal lighting system provided in the building. The lighting must, of course, generate sufficient candlepower, as for example 30-foot candles or up, to cause energization of a photocell. However, the conventional lighting system is normally sufficient for this purpose.

As previously mentioned, all of the circuit components excepting the photocells and cage switches are provided in the remote monitor 16. The monitor structure is illustrated in I FIGS. 6 and 7. As will be noted, the monitor 16 includes 8. casing 216 with an open bottom which receives a chassis 218. The various lamps and switches 66, 112 are mounted in the front face of the casing. The relays, which assume the usual physical form of a can construction, are received in sockets 220 provided in the chassis. A cable 222 is connected to the chassis to provide the various interconnecting leads necessary.

Operation of the system may now be understood. Every morning, before beginning normal banking operations, the operator of the monitor 16 stations himself at the monitor. In cooperation with the various tellers, he inserts a key into the switch 112 and turns it to the OFF position. In this position, the distant alarm is disconnected by the switch 112 and a circuit is made through the test lamp 132. The monitor operator knows that his monitor has been energized in the right position by energization of the lamp 132. At this time, each of the tellers enters his cage and places treasury bills in the compartments to cover the various photocells. Each teller then closes his energizing switch. All of the

amber lights

70, 82, 94 should be energized upon closure of the

switches

72, 84, 96. The monitor operator checks the row of amber lights against cages which he knows are occupied. If any amber light does not go on, he may then check out the cage to determine what the fault is. None of the

red alarm lamps

68, 80, 92 should be lit at this time. If any of these lamps are lit, the monitor operator may check the matter out.

Once the monitor operator is sure that each occupied cage is properly connected to the alarm system, he may then turn the switch 112 to the ON position. This will result in the arm 130 closing contacts 114 and the arm 128 closing contacts 108 while the arm 126 opens contacts 110. Opening of contacts will cause the lamp 132 to be deenergized while closing of contacts 108 will cause the lamp 134 to be energized. Energization of lamp 134 will be registered on the monitor and the monitor operator will at this time be sure that the system is in the ON condition.

In the event of a bank robbery, any teller in any cage who removes all of the treasury bills from a compartment which has a photocell will cause one of the relay coils 64 et al. being energized as a result of a circuit being completed through the photocell to power, it being appreciated that impingement of light on the photocells causes them to go from a nonconducting state to a conducting state. Energization of one of these coils will cause closing of one set of contacts 64a et al. which will be registered on the monitor circuit and apprise the monitor operator that an emergency exists in one of the cages and will specify at which cage the emergency is.

At the same time, the second set of contacts of the relay coil will close, namely, one of the contacts 6411 et al., will close. This will result in a power circuit completed through the relay coil 152 and the timer structure 154. Completion of the circuit through the relay coil 152 will result in closure of contacts 152a and 152b. The contacts 152a will close the circuit to the distant alarm 121 which may be, for example, located at the nearest police station. Energization of the distant alarm will apprise the police that an emergency, likely a robbery, exists at the bank and the police will then be able to take the necessary action. A short time after energization of the distant alarm, the timer structure 154 will cause the contacts 154a to open, The time period may be, for example, about 5 seconds. The reason for this is that it is undesirable to continuously energize the distant alarm. Such distant alarms are frequently connected to recording devices such as electronic or mechanical tapes. Continuous energization of the distant alarm over a period of time as for example, 30 or 40 minutes, may result in an undesirably long recordation of the fact of the incoming alarm.

At the same time the distant alarm is sounded, the local alarm 157 of the circuit 12 is also energized by closure of the contacts 15%. The local alarm may be any number of devices strategically located in the bank as, for example, a telephone, warning light system, or buzzer system in an isolated room or a camera in the bank which may either be turned or if of the continuous running type, made to run faster. The local alarm may alert security forces within the bank to the existence of the emergency who may then take any action which is necessary or feasible.

At the termination of the emergency situation, treasury bills are replaced over any photocells from which they have been removed and then the reset switch 66 is opened to discontinue the power supply to the relay coils 64 et al. which have been energized as a result of the emergency. As soon as the photocells have been recovered by treasury bills and the contacts 64a et al. in the cage or cages in which the emergency occurred have been reopened as a result of deenergization of the relay coil, the reset switch 66 is closed and the system is again operational. Before beginning operation of the circuit, the monitor operator should make a checkout of the system similar to that normally made prior to beginning of operations in the morning.

FIG. 8 illustrates a modified version of the circuitry provided in the tellers cages. The circuit 224 is basically similar to that illustrated in FIG. 1. A fuse 34, transformer 24, amber lamp 70, relay coils 64, switch 72, alarm lamp 68, reset switch 66 and relay contacts 64a are arranged in circuitry as hereinbefore described. However, the

photocells

226, 228 are arranged in a single lead 230 in series relationship rather than in parallel relationship as described in connection with FIG. 1. As a consequence, in the FIG. 8 embodiment, it is necessary for the teller to remove all the treasury bills from both compartments which have the photocells rather than from a single compartment in order for the alarm to be sounded. The reason for this is to prevent inadvertent alarms from being registered. lt frequently happens that a teller, by mistake or for counting, may remove money from one of the compartments without the existence of an emergency situation. The denominations of the bills are so chosen as to almost invariably result in a robber requesting the bills from both compartments having photocells so that the chance of not registering an alarm when necessary is minimal with the circuit shown in FIG. 8.

The alarm system has been described in connection with bank use. However, it will be readily apparent that this alarm system may be utilized in other environments normally subject to exposure to robbers, such as jewelry stores, large retail stores, and like businesses where valuable articles are carried as a normal function of a business.

What I claim as my invention is:

I. An electrical alarm system comprising a photocell circuit and a monitoring device therefor, said photocell circuit having at least one electric photocell mounted in a position for normal coverage by a stack of treasury bills, said monitoring device being located remotely from said photocell, a source of light positioned to impinge light rays onto the photocell and energize the photocell to a conducting state when the stack of treasury bills is removed, a first electrical relay having a coil connected in series with the photocell, a source of electric power connected across the photocell and relay coil, said first electrical relay having a first set of normally open contacts, a second electrical relay having a coil connected in series with the first set of contacts of the first relay and across said source of electric power, said first and second electrical relays being located in said monitoring device, an electrical alarm circuit, said second relay having a set of normally open contacts connected in said alarm circuit and adapted to energize the alarm circuit upon closure, said first relay having a second set of normally open contacts which are connected in parallel with said photocell to maintain energization of the first relay coil in the event said photocell is deenergized, a normally closed manually operable reset switch in series with said second set of contacts of the first relay, said reset switch being operable to selectively deenergize the coil of the first relay upon deenergization of the photocell, a first indicator lamp mounted on said monitoring device in parallel with said photocell, a manually operable switch mounted on said monitoring device in series with the photocell effective when closed and with the photocell covered by the stack of treasury bills to cause energization of said first indicator lamp and display to a viewer at said monitoring device that the photocell circuit has been energized and that the circuit is in an operative state, and a second indicator lamp mounted on said monitoring device connected in series with the photocell and being energized upon energization of the photocell to a conducting state as a result of the unauthorized removal of the stack of treasury bills to indicate to a viewer at said monitoring device that an. emergency situation has arisen, the energization of said photocell to a conducting state causing energization of the first relay coil, closure of the first set of contacts, energization of the coil of the second relay and the resultant closure of the contacts of said second relay and finally the energization of said alarm circuit.

2. An electrical alarm system as defined in claim 1, and further characterized in the provision of an electrical timer in series with the contacts of the first relay and energized upon closure of said contacts, said timer having a set of normally closed contacts in series with the contacts of said second relay, said timer being operative to cause opening of its contacts and deenergization of the alarm circuit a predetermined time after energization of the timer.

3. An alarm system as defined in claim 1, and further characterized in that said alarm circuit includes a signalling device located at a security station physically. distant from the thus described electrical circuitry, and a second alarm circuit, said second relay having a second set of normally open contacts connected in said second alarm circuit and adapted to energize the alarm circuit upon closure, said second alarm circuit including a triggering device located physically near to the thus described electrical circuitry.

4. An alarm system as defined in claim I, and further characterized in the provision of at least two photocells connected in parallel whereby energization of either photocell to a conducting state will result in energization of the alarm circuit.

5. An alarm system as defined in claim I, and further characterized in the provision of at least two photocells connected in series whereby both photocells must be energized to the conducting state before energization of the alarm circuit.

6. An alarm system as defined in claim I, and further characterized in the provision of a key-operated double-throw on-off switch on said monitor, said key-operated switch having an OFF position including a set of contacts in parallel with the photocell circuitry and closed when the on-off switch is manipulated to the off position, a lamp in series with said contacts, said lamp being mounted on the monitor and being energized upon closure of the OFF position contacts and application of electrical power to the photocell circuit whereby the monitor will indicate to a viewer that the photocell circuit has been energized, said switch having two sets of contacts which are closed in the ON" position, one set of said contacts being in series with the contacts of the second relay, the other set of said contacts being connected in series with the contacts of the first relay whereby the alarm system is made functionally operative by manipulation of said switch to the ON" position.

7. An alarm system as defined in claim 1, and further characterized in the provision of a plurality of photocell circuits which are connected in parallel.

8. An alarm system as defined in claim 1, and further characterized in the provision of a generally rectangular block in the shape of a treasury bill, said photocell being mounted in said block, a compartment for storage of said treasury bills, said block being received in said compartment, the periphery of said block being of smaller dimensions than the size of a treasury bill whereby a treasury bill covering the photocell may be easily removed by insertion of the fingers over the portion of a treasury bill which overhangs the block 9. An electrical alarm system comprising a plurality of photocell circuits and a monitoring device therefor, each circuit including an electrical photocell and a first electrical relay having a first relay coil and normally open first relay coil contacts, said monitoring device being located remotely from said photocell, each photocell mounted in a position for normal coverage by an article of value, a source of light positioned to impinge light rays onto the photocells and energize a photocell to a conducting state when the photocell is uncovered, the first relay coil of each photocell circuit being connected in series with its photocell, said series-connected photocell and first relay coil contacts being connected in parallel in said plurality of photocell circuits, a source of electric power connected across the photocells and associated relay coils of said plurality of photocell circuits, the normally open first relay coil contacts being connected in parallel in said plurality of photocell circuits, a second electrical relay for each photocell circuit having a coil connected in series with the parallel connected contacts of the corresponding first relay coil and across said source of electric power, said first and second electrical relays being located in said monitoring device, and an electrical alarm circuit, said second relay having a set of normally open contacts connected in said alarm circuit and adapted to energize the alarm circuit upon closure, a key-operated double-throw on-off switch mounted on said monitoring device, said key-operated switch having an OFF" position including a set of contacts in parallel with the photocell circuitry and closed when the key-operated switch is manipulated to the OFF position, an electrical signaling device in series with the contacts of said OFF" position, said signaling device being energized upon closure of the OFF position contacts and application of electrical power to the photocell circuits, said key-operated switch having two sets of contacts which are closed in the ON position, one set of said last-mentioned contacts being in series with the contacts of the second relay, the other of said last-mentioned contacts being connected in series with the contacts of the first relays whereby the alarm system is made functionally operative by manipulation of said key-operated switch to the ON" position with the result that uncovering of a photocell will cause energization of its associated first relay coil and closure of the contacts thereof to cause energization of the coil of the second relay with resultant closure of its contacts and energization of the alarm circuit.

Claims

1. An electrical alarm system comprising a photocell circuit and a monitoring device therefor, said photocell circuit having at least one electric photocell mounted in a position for normal coverage by a stack of treasury bills, said monitoring device being located remotely from said photocell, a source of light positioned to impinge light rays onto the photocell and energize the photocell to a conducting state when the stack of treasury bills is removed, a first electrical relay having a coil connected in series with the photocell, a source of electric power connected across the photocell and relay coil, said first electrical relay having a first set of normally open contacts, a second electrical relay having a coil connected in series with the first set of contacts of the first relay and across said source of electric power, said first and second electrical relays being located in said monitoring device, an electrical alarm circuit, said second relay having a set of normally open contacts connected in said alarm circuit and adapted to energize the alarm circuit upon closure, said first relay having a second set of normally open contacts which are connected in parallel with said photocell to maintain energization of the first relay coil in the event said photocell is deenergized, a normally closed manually operable reset switch in series with said second set of contacts of the first relay, said reset switch being operable to selectively deenergize the coil of the first relay upon deenergization of the photocell, a first indicator lamp mounted on said monitoring device in parallel with said photocell, a manually operable switch mounted on said monitoring device in series with the photocell effective when closed and with the photocell covered by the stack of treasury bills to cause energization of said first indicator lamp and display to a viewer at said monitoring device that the photocell circuit has been energized and that the circuit is in an operative state, and a second indicator lamp mounted on said monitoring device connected in series with the photocell and being energized upon energization of the photocell to a conducting state as a result of the unauthorized removal of the stack of treasury bills to indicate to a viewer at said monitoring device that an emergency situation has arisen, the energization of said photocell to a conducting state causing energization of the first relay coil, closure of the first set of contacts, energization of the coil of the second relay and the resultant closure of the contacts of said second relay and finally the energization of said alarm circuit.

3. An alarm system as defined in claim 1, and further characterized in that said alarm circuit includes a signalling device located at a security station physically distant from the thus described electrical circuitry, and a second alarm circuit, said second relay having a second set of normally open contacts connected in said second alarm circuit and adapted to energize the alarm circuit upon closure, said second alarm circuit including a triggering device located physically near to the thus described electrical circuitry.

4. An alarm system as defined in claim 1, and further characterized in the provision of at least two photocells connected in parallel whereby energization of either photocell to a conducting state will result in energization of the alarm circuit.

5. An alarm system as defined in claim 1, and further characterized in the provision of at least two photocells connected in series whereby both photocells must be energized to the conducting state before energization of the alarm circuit.

6. An alarm system as defined in claim 1, and further characterized in the provision of a key-operated double-throw on-off switch on said monitor, said key-operated switch having an ''''OFF'''' position including a set of contacts in parallel with the photocell circuitry and closed when the on-off switch is manipulated to the off position, a lamp in series with said contacts, said lamp being mounted on the monitor and being energized upon closure of the ''''OFF'''' position contacts and application of electrical power to the photocell circuit whereby the monitor will indicate to a viewer that the photocell circuit has been energized, said switch having two sets of contacts which are closed in the ''''ON'''' position, one set of said contacts being in series with the contacts of the second relay, the other set of said contacts being connected in series with the contacts of the first relay whereby the alarm system is made functionally operative by manipulation of said switch to the ''''ON'''' position.

8. An alarm system as defined in claim 1, and further characterized in the provision of a generally rectangular block in the shape of a treasury bill, said photocell being mounted in said block, a compartment for storage of said treasury bills, said block being receivEd in said compartment, the periphery of said block being of smaller dimensions than the size of a treasury bill whereby a treasury bill covering the photocell may be easily removed by insertion of the fingers over the portion of a treasury bill which overhangs the block.

9. An electrical alarm system comprising a plurality of photocell circuits and a monitoring device therefor, each circuit including an electrical photocell and a first electrical relay having a first relay coil and normally open first relay coil contacts, said monitoring device being located remotely from said photocell, each photocell mounted in a position for normal coverage by an article of value, a source of light positioned to impinge light rays onto the photocells and energize a photocell to a conducting state when the photocell is uncovered, the first relay coil of each photocell circuit being connected in series with its photocell, said series-connected photocell and first relay coil contacts being connected in parallel in said plurality of photocell circuits, a source of electric power connected across the photocells and associated relay coils of said plurality of photocell circuits, the normally open first relay coil contacts being connected in parallel in said plurality of photocell circuits, a second electrical relay for each photocell circuit having a coil connected in series with the parallel connected contacts of the corresponding first relay coil and across said source of electric power, said first and second electrical relays being located in said monitoring device, and an electrical alarm circuit, said second relay having a set of normally open contacts connected in said alarm circuit and adapted to energize the alarm circuit upon closure, a key-operated double-throw on-off switch mounted on said monitoring device, said key-operated switch having an ''''OFF'''' position including a set of contacts in parallel with the photocell circuitry and closed when the key-operated switch is manipulated to the ''''OFF'''' position, an electrical signaling device in series with the contacts of said ''''OFF'''' position, said signaling device being energized upon closure of the ''''OFF'''' position contacts and application of electrical power to the photocell circuits, said key-operated switch having two sets of contacts which are closed in the ''''ON'''' position, one set of said last-mentioned contacts being in series with the contacts of the second relay, the other of said last-mentioned contacts being connected in series with the contacts of the first relays whereby the alarm system is made functionally operative by manipulation of said key-operated switch to the ''''ON'''' position with the result that uncovering of a photocell will cause energization of its associated first relay coil and closure of the contacts thereof to cause energization of the coil of the second relay with resultant closure of its contacts and energization of the alarm circuit.