US3883866A

US3883866A - Alarm generator

Info

Publication number: US3883866A
Application number: US388225A
Authority: US
Inventors: John K Kneeland
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-08-14
Filing date: 1973-08-14
Publication date: 1975-05-13
Anticipated expiration: 1992-05-13

Abstract

The alarm generator furnishes a coded signal which is repeated in accordance with predetermined events which may occur on the premises at which the generator is located, such as fire, burglary, and equipment failure. After a central station has been apprised of the occurrence of an event by transmitting the requisite number of rounds of the coded signal, the alarm generator is reset by transmitting another round or rounds of the coded signal such that the number of rounds sent to apprise the central station of an event plus the number of rounds sent in resetting the alarm generator is constant.

Description

Kneeland 1451 May 13, 1975 ALARM GENERATOR [76] Inventor: John K. Kneeland, Mill Ln., Old

Lyme, Conn. 06371 22 Filed: Aug. 14,1973

21 Appl. No.: 388,225

Ward 340/293 Lamonaco 340/293 X Primary Examiner-John W. Caldwell Assistant ExaminerWilliam M. Wannisky Attorney, Agent, or Firm-Prangley, Dithmar, Vogel, Sandler & Stotland [57] ABSTRACT The alarm generator furnishes a coded signal which is repeated in accordance with predetermined events which may occur on the premises at which the generator is located, such as fire, burglary, and equipment failure. After a central station has been apprised of the occurrence of an event by transmitting the requisite number of rounds of the coded signal, the alarm generator is reset by transmitting another round or rounds of the coded signal such that the number of rounds sent to apprise the central station of an event plus the number of rounds sent in resetting the alarm generator is constant 11 Claims, 7 Drawing Figures CUSTOM ER CUSTOMER SHEET 10F 2 CUSTOMER FIG. 2

PATENTED RAY I 3 I975 SHEET 2 BF 2 I CENTRAL STATION ALARM GENERATOR BACKGROUND OF THE INVENTION This invention relates generally to the field of security systems wherein alarm generators are respectively located in a number of premises, such as the apartments in an apartment building, all of the premises beings connected to a central station by way of a common line. The system utilizes waht is commonly referred to as the McCullough loop, wherein each alarm generator is assigned a specific code, and when an event occurs at that station, the alarm generator transmits to the central station that code.

In the past, alarm systems of this general type were capable of transmitting to the central station information as to a single event, such as the occurrence of a burglary, of fire or equipment failure, etc. If the customer wished the central station to supervise the occurrence of the other events, he would have to purchase additional equipment.

SUMMARY OF THE INVENTION It is, therefore, an important object of the present invention to provide an alarm generator which is capable of transmitting information regarding the occurrence of one of a plurality of events, such as the occurrence of a burglary, a fire, equipment failure, the existence of general emergency panic," etc.

The invention consists of certain features of construction, and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the structure may be made without departing from the spirit or sacrificing any of the advantages of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the invention, its mode of construction, assembly and operation, and many of its advantages should be readily understood and appreciated.

FIG. 1 illustrates an alarm System in which alarm generators in a plurality of premises are connected in series with the receiver at a central station;

FIG. 2 is a plan view of an alarm generator incorporating the features of the present invention;

FIG. 3 is a view in vertical section taken along the line 33 of FIG. 2;

FIG. 4 is a plan view on an enlarged scale of the code wheel used in the alarm generator, together with a McCollough switch;

FIG. 5 is a view in vertical section taken along the line 55 of FIG. 2;

FIG. 6 is a schematic illustration of the mechanical and electrical connections in the alarm generator of FIG. 2; and

FIG. 7 is a block diagram like FIG. 1 but illustrating some of the other details of the alarm generators in each of the premises.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to the drawings, and more particularly to FIG. 1 thereof, there is illustrated an alarm system 10 in which one of several events occurring at a customers location is to be relayed to a central station 11. The alarm system 10 of FIG. 1 illustrates an example in which three blocks representing three remote points are shown. Each remote point signifies a customer, such as an apartment in a condominium or apartment building. Thus, for example, a block within which is inscribed Customer 233 means a given apartment in the building and the block within which is inscribed Customer 234 represents another apartment in the building. The block within which is inscribed Customer n" represents yet another apartment in the building. A series of dashes is noted between the Customer 234 and Customer n signifying that any desired number of apartments may be hooked up in the alarm system 10. The connections represent electrical connections between the alarm generators in the individual apartments and the central station 11. Thus, the alarm generators in all of the apartments in the building are connected in series with the receiver that is located in the central station 11. It is further noted that such receiver is grounded as is the alarm generator in each apartment. The reasons for this will become more apparent hereinafter.

Basically, the alarm system depicted in FIG. 1 operates on the principle of a McCullough loop wherein all of the alarm generators share a common line. When an event occurs in one of the apartments, a code signal representation of that apartment only is transmitted to the central station 11. Thus, for example, if an event occurred in the apartment labeled Customer 233, the alarm generator therein would produce a signal representing the number 233. The central station 11 would then be apprised that an event has occurred in the corresponding apartment. As will become more clear hereinafter, the number of times the code is repeated represents the kind of event that has occurred, to wit, fire, burglary, equipment failure, etc.

Turning now to FIG. 2, the details of the alarm generator used in one of the apartments will be described. The alarm generator of FIG. 2 is represented generally by the numeral 20. The alarm generator 20 includes a main plate 21 with an opening therein through which the motor 57 (FIG. 6) protrudes. There is also provided a subplate 22 which is secured to the main plate 21 by means of screws 23. Mounted on the main plate 21 is a terminal strip 24 having thirteen terminals 25 connected to the various elements of the alarm generator 20, and are used for making external connections to the power supply, to the telephone line, etc.

The alarm generator 20 includes a McCullough switch 30 including a base 31 secured to the subplate 22. The McCullough switch 30 has a pair of spaced apart

flexible arms

32 and 33 mechanically mounted on the base 31, the arm 32 having a finger 34 at the end thereof remote from the base 31. The arm 33 is biased counterclockwise so that its free end abuts against a post 35. Contacts 36 are respectively caried by the

arms

32 and 33 near the outer ends thereof. The switch 30 also includes a second pair of

arms

37 and 38 carried by the base 31 and located beneath the

arms

32 and 33. A finger 39 is carried by the arm 37. The arm 38 is also biased counterclockwise so that its outer end abuts against a post 40. Contacts 41 are respectively carried by the

arms

37 and 38 near the outer ends thereof. Wiring 42 electrically connects the

arms

32, 33, 37 and 38, to certain of the terminals on the terminal strip 24.

The alarm generator 20 further includes a code wheel which has a plurality of outwardly directed teeth 51 thereon. The code wheel 50 has a central opening therein which nonrotatably receives the neck 53 of a gear (not shown) which gear engages a gear

train including gears

54, 55 and 56. A motor 57 (FIG. 6) is opcratively connected to the gear 55 so that the operation of the motor causes rotation of the code wheel 50. The code is transmitted by opening and closing the contacts 36 and the contacts 41. As the motor 57 rotates the code wheel 50 counterclockwise, the finger 34 travels up the side of a tooth 51 on the wheel 50 and the contacts 36 close. As the wheel 50 continues to rotate, the finger 34 falls between the teeth 51 and the contacts 36 open. The opening and closing of the contacts 36 produces a pulse on the transmission line (not shown) connected to certain terminals 25. One revolution of the wheel 50 generates a round of pulses corresponding to the code for the alarm generator 20. The contacts 41 are similarly opened and closed by virtue of the finger 39 being operated by the wheel 50. However, as can be seen from FIG. 2, the finger 39 is slightly behind the finger 34 so that the pulses produced by opening and closing of the contacts 41 is time delayed with respect to the pulses produced by opening and closing of the contacts 36. Thus, on the transmission line there will appear two sequences ofpulses, one delayed in time with respect to the other. These pulses will be received by the receiving station 11 and may, if desired, be recorded by a suitable double pen register.

The particular sequence of pulses for indicating which station is transmitting is determined by the teeth 51 remaining in the code wheel 50. Certain teeth, such as those shown in dotted lines in FIG. 4, have been removed to provide spaces leaving the rest to provide pulses for transmission. In the example illustrated, the first through third, sixth, tenth, fourteenth and fifteenth teeth have been removed. Thus, the wheel 50 includes two teeth followed by a space, followed by three teeth, followed by a space, followed by three teeth, followed by a space. Accordingly, the code signal generated by the alarm generator corresponds to the number 233. The number 233 indicates the particular generator in the overall alarm system. The number of times that the number 233 is generated, that is, the number of rounds, indicates the type of event which has occurred, as will be explained.

Turning now to FlG. 6, further elements of the alarm generator will be described. There is provided a relay 60 having a winding 61 having one end coupled to ground and the other end coupled to an equipment failure input 62. A bar 63 represents a short which would occur when a piece of monitored equipment fails, causing a B+ supply voltage to be coupled to the relay winding 61 thereby energizing same. The relay 60 includes a pair of latching or holding contacts 64a and 64!), the movable contact 64!) being coupled to the winding 61. The relay includes a further set of contacts 65, including stationary contacts 65a and 65b and a movable contact 650. The equipment failure portion also includes a cam operated switch 67 having fixed

contacts

67a and 67b and a movable contact 670. The fixed contact 67a is connected to the fixed contact 650 of the relay 60, and the contact 67b is connected to the contact 6512.

The alarm generator also has a relay 70 including a winding 71 having one end coupled to ground and the other end coupled to a burglary input 72. A bar 73 represents a short which would occur when a door or window of the premises is opened, causing a 8+ supply voltage to be coupled to the relay winding 71 thereby energizing same. The relay 70 includes a pair of latching or holding contacts 74a and 7417, the movable contact 741) being coupled to the winding 71. The relay 70 also includes a set of contacts 75, including stationary contacts 75a and 75b and a movable contact 750. The relay 70 includes a pair of contacts 76 respectively coupled to 8+ and to burglar-alarm generator. When the contacts 76 are closed, B+ is supplied to the alarm generator to cause an alarm such as a siren. flashing light, etc. to occur. The burglar alarm portion also includes a cam operated switch 77 having fixed contacts 771: and 77b and a movable contact 77c. The fixed contact 77a is connected to the fixed contact 75a of the relay 70, and the contact 77b is connected to the contact 75b.

The alarm generator also has a relay 80 including a winding 81 having one end coupled to ground and the other end coupled to a fire input 82. A bar 83 represents a short which takes when a fire occurs causing a 8+ supply voltage to be coupled to the relay winding 81 thereby energizing same. The relay 80 includes a pair of latching or holding contacts 84a and 8412, the contact 84a being connected to the contacts 64a and 74a. It also includes a set of

stationary contacts

85a and 85b and a movable contact 850, which contact 85c is coupled to the B-lsupply voltage. The relay 80 includes a pair of contacts 86 respectively coupled to B+ and to a fire alarm. When the contacts 86 are closed, 8+ is supplied to a alarm to cause an alarm such as a siren, flashing light, etc. to occur. The fire alarm portion also includes a cam operated switch 87 having fixed contacts 87a and 87b and a movable contact 87c. The fixed contact 87a is connected to the fixed contact 85a of the relay 80, and the contact 8712 is connected to the contact 851).

The alarm generator 20 includes reset circuitry, including a reset relay 90 having a winding 91, one end of the winding 91 being connected to the B+ supply voltage and the other end being connected through a pushbutton switch 93 to ground reference potential. The relay 90 also includes a set of fixed

contacts

94a and 94b and movable contact 94c. The movable contact 94c is coupled to the B+ supply voltage; the fixed contact 94a is coupled to the high end of the relay winding 71. The fixed contact 94b is connected to the fixed contacts 6411,7411 and 84a. There also is provided a cam operated switch 97 having a fixed contact 97a coupled to the B+ supply voltage and a movable contact 97c.

The

movable contacts

67c, 77c, 87c and 97c are respectively coupled together and to one terminal of the motor 57 which is DC operated, the other terminal of the motor being connected to ground reference potential. A B+ voltage on the first mentioned terminal of the motor 57 causes it to operate and, therefore, rotate the code wheel 50 as previously explained.

The alarm generator also includes control mechanisms for the cam operated switches. To operate the cam operated switch 67, there is provided a first cam 100 having a raised portion 101 and a recessed portion 102. The movable contact 670 is biased counterclockwise and has a finger at its outer end which rides on the cam 100. When it is on the portion 101, the

contacts

67b and 67 c are closed, whereas when it enters the portion 102, the contact 67(- engages the contact 67a. To operate the cam operated switch 77, there is provided a cam 110 having a raised portion 111 and a recessed portion 112. The movable contact 770 is biased counterclockwise and has a finger at its outer end which rides on the cam 110. When it is on the portion 111, the contacts 77b and 770 are closed, whereas when it enters the portion 112, the contact 77c engages the contact 77a. To operate the cam operated switch 87, there is provided a cam 120 having a raised portion 121 and a recessed portion 122. The movable contact 870 is biased counterclockwise and has a finger at its outer end which rides on the cam 120. When it is on the portion 121, the

contacts

87b and 87c are closed, whereas when it enters the portion 122, the contact 870 engages the contacts 87a.

There is provided a fourth cam 130 having a raised portion 131 and four notches 132. The movable contact 970 is biased counterclockwise and has a finger at its outer end which rides on the cam 130. When it is on the portion 131, the

contacts

97a and 97c are closed, whereas when it enters any of the notches 132, the contact 970 disengages the contact 97a.

The

cams

100, 110, 120 and 130 are ganged together onto a shaft 145, the cams being separated by spacers 146. A gear 147 mounted on the shaft 145 engages the gear 54. Thus, operation of the motor 57 causes the cam stack consisting of the

cams

110, 120, 130 and 140 to rotate counterclockwise and respectively operate the cam operated switches 67, 77, 87 and 97, respectively. FIGS. 2 and 6 illustrate the positions of the cams in their initial positions prior to the occurrence of any event. The gear ratio of the gears between the motor 57, the code wheel 50 and the cam stack is such as to cause the code wheel 50 to make five revolutions for every revolution of the cam stack, or stated otherwise, every time the cam stack rotates about 72, the code wheel 50 will make a revolution and, therefore, cause transmission of one round of the code signal.

If an equipment failure occurs so that the bar 63 shorts the B+ supply voltage to the equipment failure input 62, the relay winding 61 is energized to close the contacts 64ab, whereby 8+ is supplied to the relay winding 61 through the contacts 9412-0 and the contacts 64ab to maintain the relay 60 energized even if the B+ is removed from the input 62. Energization of the relay winding 61 closes the contact 64b-c to provide a connection from the B+ supply voltage through the contacts 85a-c, 75a-c, 6512-0, 67b-c, to the motor 57 to cause it to rotate the cam stack counterclockwise. Specifically, the cam 100 rotates counterclockwise and as long as the contact 67c rides on the portion 101, power continues to be supplied to the motor 57. When the biasing of the contact 67c causes it to enter the recessed portion 102, which occurs in the illustrated example about 288 after the stack begins to rotate, the contacts 67b-c open to disrupt power to the motor 57. the 288 of rotation of the cam stack causes the code wheel 50 to rotate four revolutions and, therefore,

causes transmission of four rounds of the code signal.

It is to be noted that the relay continues to be energized by virtue of the holding contacts 64ab being closed. The counterclockwise movement of the contact 670 causes it to engage the contact 67a preparatory to resetting the alarm generator 20. Such reset is accomplished by depressing the switch 93 which energizes the winding 91 of the relay 90 causing the contacts 94b-c to open, thereby to disrupt current to the winding 61. The relay 60 is thereby de-energized causing the contacts 65a-c to close. Now B-lis coupled, by way of the contacts 85a-c, 75ac, 65a-c and 67a-c to the motor 57, thereby supplying power thereto. The motor 57 rotates the cam stack and the code wheel 50. When the cam 100 has rotated counterclockwise about 72, the portion 101 will move the contact 670 out of engagement with the contact 67a thereby disrupting power to the motor 57. The contacts 67bc will be engaged preparatory to the occurrence of a subsequent event.

The rotation of the cam stack about 72 caused one revolution of the code wheel 50 thereby sending one round of the code signal. It should be noted that in all, five rounds of the code signal were sent, four to advise the central station of the occurrence of an equipment failure and one to reset the alarm generator 20 back to its initial position, preparatory to occurrence of the next event. The central station 11 recognizes the code signal as that of a specific premises and recognizes four rounds of that code signal as indicative of the occurrence of an equipment failure and acts accordingly.

If a burglary occurs so that the bar 73 shorts the B+ supply voltage to the burglar input 72, the relay winding 71 is energized to close the contacts 74ab, whereby B-lis supplied to the relay winding 61 through the contacts 94b-c and the contacts 74ab to maintain the relay energized even if the B+ is removed from the input 72. Energization of the relay winding 71 also closes the contacts 75bc to provide a connection from the 3-:- supply voltage through the contacts ac, 7Sb-c, 77b-c to the motor 57 to cause it to rotate the cam stack counterclockwise. Specifically, the cam 110 rotates and as long as the contact 770 rides on the portion 111, power continues to be supplied to the motor 57. As soon as the biasing of the contact 770 causes it to enter the recessed portion 112, which occurs in the illustrated example about 216 after the stack began to rotate, the contacts 77b-c open to disrupt power to the motor 57. The 216 of rotation of the cam stack causes the code wheel 50 to make three revolutions and, therefore, causes transmission of three rounds of the code signal.

It is to be noted that the relay 70 continues to be energized by virtue of the holding contacts 74a-b being closed. The counterclockwise movement of the contact 770 causes it to engage the contact 77a preparatory to resetting the alarm generator 20. Such reset is accomplished by depressing the switch 93 which energizes the winding 91 of the relay causing the contacts 94b-c to open thereby to disrupt current to the winding 71. the relay 70 is thereby de-energized causing the contacts 75ac to close. Now B+ is coupled, by way of the contacts 85a-c, 75a-c and 77a-c to the motor 57, thereby supplying power thereto. The motor 57 rotates the cam stack and the code wheel 50. When the cam has rotated counterclockwise about 144, the portion 111 will move the contact 770 out of engagement with the contacts 77a, thereby disrupting power to the motor 57. The contacts 7712- will be engaged preparatory to the occurrence of a subsequent event. The rotation of the cam stack about 144 caused two revolutions of the code wheel 50 thereby sending two rounds of the code signal. It should be noted that in all, five rounds of the code signal were sent, three to advise the central station of the occurrence of a burglary and two to reset the alarm generator back to its initial position preparatory to the occurrence of the next event. The central station recognizes the code signal as that of a specific premises and recognizes three rounds of that code siganl as indicative of the occurrence of a burglary and acts accordingly.

lfa fire occurs so that the bar 83 shorts the B+ supply voltage to the fire input 82, the relay winding 81 is energized to close the contacts 84ab, whereby 13+ is supplied to the relay winding 81 through the contacts 9417-0 and the contacts 8411-19 to maintain the relay 81 energized even if the 8+ is removed from the input 82. Energization of the relay winding 81 also closes the contacts 8517-0 to provide a connection from the B+ supply voltage through the contacts 8512-0, 87bc, to the motor 57 to cause it to rotate the cam stack counterclockwise. Specifically, the cam 120 rotates counterclockwise and as long as the contact 87c rides on the portion 111, power continues to be supplied to the motor 57. When the biasing of the contact 876 causes it to enter the recessed portion 122, which occurs in the illustrated example about 144 after the stack begins to rotate, the contacts 8711-0 open to disrupt power to the motor 57. The 144 of rotation of the cam stack causes the code wheel 50 to make two revolutions and, therefore, causes transmission of two rounds of the code signal.

It is to be noted that the relay 80 continues to be energized by virtue of the holding contacts 84ab being closed. The counterclockwise movement of the contact 870 causes it to engage the contact 870 preparatory to resetting the alarm generator 20. Such reset is accomplished by depressing the switch 93 which energizes the winding 91 of the relay 90 causing the contacts 94b-c to open, thereby to disrupt current to the winding 81. The relay 60 is thereby de-energized causing the contacts 85ac to close. Now B+ is coupled, by way of the contacts 85a-c and 87a-c to the motor 57, thereby supplying power thereto. the motor 57 rotates the cam stack and the code wheel 50. When the cam 120 has rotated counterclockwise about 216, the portion 121 will move the contact 876 out of engagement with the contact 870 thereby disrupting power to the motor 57. the contacts 87b-c will be engaged preparatory to the occurrence of a subsequent event.

The rotation of the cam stack about 216 causes three revolutions of the code wheel 50 thereby sending three rounds of the code signal, It should be noted that in all, five rounds of the code signal were sent, two to advise the central station of the occurrence of a fire and three to reset the alarm generator 20 back to its initial position, preparatory to occurrence of the next event. The central station 11 recognizes the code siganl as that of specific premises and recognizes two rounds of that code signal as indicative of the occurrence of a fire and acts accordingly.

There are also provisions for manual operation of the alarm generator 20 to apprise the central station 11 of, for example, a medical emergency or other panic situation. Also, if a burglar enters the premises when the burglar alarm portion of the system has not been set, the occupant may wish to operate the generator 20 manually.

This is accomplished by depressing the switch 93 thereby completing a path for current flow through the winding 91, to cause closure of the contacts 94a-c. The B-lvoltage is thus connected to the relay winding 71 of the relay to energize same and close the contacts 75b-c. This connects the 13+ supply voltage through the contacts zzc, 75b-c and 7717-0 to the motor 57 to cause it to rotate the cam stack counterclockwise. Upon release of the switch 93, the contacts 94a-c open, preparatory to the occurrence of the next event. This de-energizes the relay winding 71 to open the contacts 74a-b.

As soon as the motor 57 operates, it rotates the cam 130 specifically to move the contact 970 to the portion 131, thereby closing the contacts 97ac. A path is then completed for the B+ supply voltage through the contacts 97ac to the motor 57 to cause it to continue to operate. After the cam stack has traversed about 144, the finger on the contact 97: enters one of the notches 132 thereby disrupting power to the motor 57 via that path. However, at that time the contact 876 has entered the recessed portion 122 of the cam to close the contacts 87a-c. This completes a path to supply the 13+ supply voltage to the motor 57 by way of the contacts 85ac and 87ac. As the cam stack continues to rotate, the finger on the contact 970 will drop out of the notches 132 and again ride on the portion 131 so that 8+ is supplied by way of both the contacts 97a-c and by way of the contacts 87ac. At the next notch 132, the contacts 77a-c will have closed so that 8+ is furnished to the motor via the contacts 85ac, 75a-c and 77a-c. 1n the last notch 132, the ac contacts of the cam operated switches 67, 77 and 87 will have closed to continue to supply power to the motor 57. When the finger on the contact 970 enters the final notch 132, as shown in FIG. 6, to disrupt power by way of the contacts 97a-c, all of the other cam operated switches will have similarly opened so that power to the motor 57 is finally disrupted.

The 360 rotation of the cam stack causes the code wheel 50 to make five revolutions and, therefore, causes transmission of five rounds of the code signal. Since the cam stack has made an entire revolution, it is already effectively reset preparatory to the occurrence of a subsequent event. It is noted that the same switch 93 which is used to reset the alarm generator 20 also functions as the manual operator for medical emergency, panic, etc.

Summarizing, the occurrence of an equipment failure will cause the cam stack to rotate about 288 thereby causing the code wheel 50 to make four revolutions, to transmit four rounds of the code signal. When the alarm generator 20 is thereafter reset, the cam stack will be caused to rotate an additional 72 so that it arrives at its point, which rotation causes one revolution of the code wheel 50 and, therefore, one round of the code signal. A burglary will cause the cam stack to rotate about 216 thereby causing the code wheel 50 to make three revolutions, to transmit three rounds of the code signal. When the alarm generator 20 is thereafter reset, the cam stack will be caused to rotate an additional 144 so that it arrives at its initial starting point, which rotation causes two revolutions of the code wheel 50 and, therefore, two rounds of the code signal. The occurrence of a fire will cause the cam stack to rotate about 144 thereby causing the code wheel 50 to make two revolutions, to transmit two rounds of the code signal. When the alarm generator is thereafter reset, the cam stack will be caused to rotate an additional 216 so that it arrives at its initial starting point, which rotation causes three revolutions of the code wheel 50 and, therefore, three rounds of the code signal, Finally, manual operation of the alarm generator, in the case of a medical emergency or other panic situation, causes the cam stack to rotate 360 thereby causing the code wheel 50 to make five revolutions, to transmit five rounds of the code signal. Thus, in the panic mode, the cam stack makes an entire revolution so that it arrives at its starting position automatically without being reset.

When each event occurs and the alarm generator is thereafter reset, five rounds in all of the code signal have been sent so that in each case the alarm generator automatically arrives at its initial condition preparatory to the occurrence of another event.

It is understood that the number of events, the kind of events, the number of rounds of the code signal, etc. described herein are merely exemplary of an alarm system incorporating the features of the present invention, Thus, for example, more or less cams and associated cam operated switches may be employed depending upon the number of events to be covered. Also the number of rounds of the code signal to be transmitted as to the occurrence of a selected event may be similarly selected.

It is believed that the invention, its mode of construction and assembly, and many of its advantages should be readily understood from the foregoing without further description, and it should also be manifest that, while a preferred embodiment of the invention has been shown and described for illustrative purposes, the structural details are, nevertheless, capable of wide variation within the purview of the invention as defined in the appended claims.

What is claimed is:

1. An alarm generator adapted to be located on a premises to be protected against the occurrence of a plurality of events, and supervised at a point remote from the premises, comprising means for producing at least one code signal for transmission to the remote point, a rotatably mounted code wheel programmed to cause said producing means to produce a predetermined code signal for each revolution of said code wheel, a motor for rotating said code wheel, a plurality of switching means for coupling power to said motor, a plurality of event inputs each providing an enabling voltage in response to occurrence of one of the plurality of events, said switching means being respectively coupled to said plurality of event inputs and each being responsive to the presence of the associated enabling voltage to couple the power to said motor, a plurality of control mechanisms respectively coupled to said plurality of switching means and operatively coupled to said motor, each of said control mechanisms having means responsive to a predetermined rotation of said motor to operate said switching means to stop said motor, whereby said code wheel is caused to rotate a number of revolutions corresponding to the predetermined rotation of said motor, and reset means for causing said switching means to deliver power to said motor, each of said control mechanisms having further means responsive to a further predetermined rotation of said motor to stop said motor, whereby said code wheel is caused to rotate a further number of revolutions corresponding to the further predetermined rotation of said motor.

2. The alarm generator of claim 1, wherein the premises are to be protected against four events, and wherein there are four switching means, four event inputs and four control mechanisms.

3. The alarm generator of claim 1, wherein said producing means includes a McCullough switch.

4. The alarm generator of claim 1, and further comprising a plurality of holding means associated with said switching means for maintaining said switching means operative to couple power to said motor for said predetermined rotation of said motor despite termination of the enabling voltage.

5. the alarm generator of claim 1, wherein said control mechanisms are ganged together.

6. The alarm generator of claim 1, further comprising a further event input to receive an enabling voltage in the presence of a further event, said reset means including means responsive to an enabling voltage at said further event input to operate said switching means and cause power to be supplied to said motor to cause a predetermined number of revolutions of said code wheel.

7. An alarm generator adapted to be located on a premises to be protected against the occurrence of a plurality of events, and supervised ata point remote from the premises, comprising means for producing at least one code signal for transmission to the remote point, a rotatably mounted code wheel programmed to cause said producing means to produce a predetermined code signal for each revolution of said code wheel, a motor for rotating said code wheel, a plurality of first switching means each having an input coupled to a power source and first and second outputs, said first switching means having an initial condition in which said input is coupled to said first output and decoupled from said second output, a plurality of event inputs each providing an enabling voltage in response to occurrence of one of the plurality of events, said plurality of first switching means being respectively coupled to said plurality of event inputs and each being responsive to the presence of the associated enabling voltage to cause said input to be coupled to said second output and decoupled from said first output, a plurality of second switching means respectively associated with said plurality of first switching means and each having an output coupled to said motor and first and second inputs respectively coupled to the outputs of said first switching means, said second switching means having an initial condition in which said output thereof is decoupled from said first input and is coupled to said second input to deliver power to said motor by way of the second output of said first switching means and the second input of said second switching means, a plurality of control mechanisms respectively coupled to said plurality of second switching means and operatively coupled to said motor, each of said control mechanisms having means responsive to a predetermined rotation of said motor to decouple said output of said second switching means from said second input to stop said motor and to couple said output thereof to said first input, whereby said code wheel is caused to rotate a numlll ber of revolutions corresponding to the predetermined rotation of said motor, and reset means for returning said first switching means to the initial condition thereof to deliver power to said motor by way of the first output of said first switching means and the first input of said second switching means, each of said control mechanisms having further means responsive to a further predetermined rotation of said motor to return the associated second switching means to the initial condition thereof and thereby stop said motor, whereby said code wheel is caused to rotate a further number of revolutions corresponding to the further predetermined rotation of said motor.

8. The alarm generator of claim 7, wherein each of said first switching means includes a relay having a movable contact corresponding to said input and two stationary contacts corresponding to said first and second outputs.

9. The alarm generator of claim 7, and further comprising a plurality of further switching means respectively associated with at least some of said first switching means and being responsive to the occurrence of an event to maintain the input and the second output of said first switching means coupled after termination of the associated enabling voltage.

10. An alarm generator adapted to be located on a premises to be protected against the occurrence of a plurality of events, and supervised at a point remote from the premises, comprising means for producing at least one code signal for transmission to the remote point, a rotatably mounted code wheel programmed to cause said producing means to produce a predetermined code signal for each revolution of said code wheel, a motor for rotating said code wheel, a plurality of switching means each having a first contact coupled to a power source and second and third contacts, said switching means having an initial condition in which said first contact is connected to said second contact and is disconnected from said third contact, a plurality of event inputs each providing an enabling voltage in response to occurrence of one of the plurality of events, said plurality of switching means being respectively coupled to said plurality of event inputs and each being responsive to the presence of the associated en abling voltage to cause said first contact to be connected to said third contact and to be disconnected from said second contact, a plurality of cam operated switches respectively associated with said plurality of switching means and each having a fourth contact coupled to said motor and fifth and sixth contacts respeetively coupled to the second and third contacts of said switching means, said cam operated switches having an initial condition in which said fourth contact thereof is disconnected from said fifth contact and is connected to said sixth contact to deliver power to said motor by way of said third and sixth contacts, a stack of a plurality of cams respectively coupled to said plurality of cam operated switches and operatively coupled to said motor, each of said cams having a portion responsive to a predetermined rotation of said motor to disconnect said fourth contact from said sixth contact to stop said motor and to connect said fourth contact to said fifth contact, whereby said code wheel is caused to rotate a number of revolutions corresponding to the predetermined rotation of said motor, and reset means for returning said switch means to the initial condition thereof to couple power to said motor by way of said second and fifth contacts, each of said cam means having a further portion thereon responsive to a further predetermined rotation of said motor to return the associated cam operated switch to the initial condition thereof and thereby stop said motor, whereby said code wheel is caused to rotate a further number of revolutions corresponding to the further predetermined rotation of said motor.

11. The alarm generator of claim 10, wherein said cams are ganged together.

Claims

7. An alarm generator adapted to be located on a premises to be protected against the occurrence of a plurality of events, and supervised at a point remote from the premises, comprising means for producing at least one code signal for transmission to the remote point, a rotatably mounted code wheel programmed to cause said producing means to produce a pre-determined code signal for each revolution of said code wheel, a motor for rotating said code wheel, a plurality of first switching means each having an input coupled to a power source and first and second outputs, said first switching means having an initial condition in which said input is coupled to said first output and decoupled from said second output, a plurality of event inputs each providing an enabling voltage in response to occurrence of one of the plurality of events, said plurality of first switching means being respectively coupled to said plurality of event inputs and each being responsive to the presence oF the associated enabling voltage to cause said input to be coupled to said second output and decoupled from said first output, a plurality of second switching means respectively associated with said plurality of first switching means and each having an output coupled to said motor and first and second inputs respectively coupled to the outputs of said first switching means, said second switching means having an initial condition in which said output thereof is decoupled from said first input and is coupled to said second input to deliver power to said motor by way of the second output of said first switching means and the second input of said second switching means, a plurality of control mechanisms respectively coupled to said plurality of second switching means and operatively coupled to said motor, each of said control mechanisms having means responsive to a predetermined rotation of said motor to decouple said output of said second switching means from said second input to stop said motor and to couple said output thereof to said first input, whereby said code wheel is caused to rotate a number of revolutions corresponding to the predetermined rotation of said motor, and reset means for returning said first switching means to the initial condition thereof to deliver power to said motor by way of the first output of said first switching means and the first input of said second switching means, each of said control mechanisms having further means responsive to a further predetermined rotation of said motor to return the associated second switching means to the initial condition thereof and thereby stop said motor, whereby said code wheel is caused to rotate a further number of revolutions corresponding to the further predetermined rotation of said motor.

10. An alarm generator adapted to be located on a premises to be protected against the occurrence of a plurality of events, and supervised at a point remote from the premises, comprising means for producing at least one code signal for transmission to the remote point, a rotatably mounted code wheel programmed to cause said producing means to produce a predetermined code signal for each revolution of said code wheel, a motor for rotating said code wheel, a plurality of switching means each having a first contact coupled to a power source and second and third contacts, said switching means having an initial condition in which said first contact is connected to said second contact and is disconnected from said third contact, a plurality of event inputs each providing an enabling voltage in response to occurrence of one of the plurality of events, said plurality of switching means being respectively coupled to said plurality of event inputs and each being responsive to the presence of the associated enabling voltage to cause said first contact to be connected to said third contact and to be disconnected from said second contact, a plurality of cam operated switches respectively associated with said plurality of switching means and each having a fourth contact coupled to said motor and fifth and sixth contacts respectively coupled to the second and third contacts of said switching means, said cam operated switches having an initial condition in which said fourth contact thereof is disconnected from said fifth contact and is connected to said sixth contact to deliver power to said motor by way of said third and sixth contacts, a stack of a plurality of Cams respectively coupled to said plurality of cam operated switches and operatively coupled to said motor, each of said cams having a portion responsive to a predetermined rotation of said motor to disconnect said fourth contact from said sixth contact to stop said motor and to connect said fourth contact to said fifth contact, whereby said code wheel is caused to rotate a number of revolutions corresponding to the predetermined rotation of said motor, and reset means for returning said switch means to the initial condition thereof to couple power to said motor by way of said second and fifth contacts, each of said cam means having a further portion thereon responsive to a further predetermined rotation of said motor to return the associated cam operated switch to the initial condition thereof and thereby stop said motor, whereby said code wheel is caused to rotate a further number of revolutions corresponding to the further predetermined rotation of said motor.

11. The alarm generator of claim 10, wherein said cams are ganged together.