US3787831A

US3787831A - Alarm system

Info

Publication number: US3787831A
Application number: US00264034A
Authority: US
Inventors: C Gordon
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-06-19
Filing date: 1972-06-19
Publication date: 1974-01-22
Anticipated expiration: 1991-01-22

Abstract

An alarm unit for hotel and motel rooms and the like is mounted on the closed door of the entranceway to the room and has series connected components that include an intruder actuated switch, a DC power source, an audible signaling device and a switching system for disarming the circuit that has an internally located array of switches which are manipulatable to establish a switching combination that can be matched by manipulating the switches of an exteriorly located array in order to gain access to the closed areas without setting off the alarm. The switching system includes parallel branch switching circuits and each circuit includes parallel branch conductors that are connected to one switch in each of the arrays and which are broken in the circuit by manipulating the pair of switches to select the same conductor. The alarm system is housed in a pair of internally and externally located housings and has a self contained power source with connective wiring between the housings extending through a tubular conduit. Provisions are also made for coin actuation and timed use of the unit and the switching arrays permit the occupant to have the sole knowledge of the combination permitting access to the room without energizing the alarm circuit.

Description

United States Patent [191 Gordon Jan. 22, 1974 1 ALARM SYSTEM [5 7 ABSTRACT An alarm unit for hotel and motel rooms and the like is mounted on the closed door of the entranceway to the room and has series connected components that include an intruder actuated switch, a DC power source, an audible signaling device and a switching system for disarming the circuit that has an internally located array of switches which are manipulatable to establish a switching combination that can be matched by manipulating the switches of an exteriorly located array in order to gain access to the closed areas without setting off the alarm. The switching system includes parallel branch switching circuits and each circuit includes parallel branch conductors that are connected to one switch in each of the arrays and which are broken in the circuit by manipulating the pair of switches to select the same conductor. The alarm system is housed in a pair of internally and externally located housings and has a self contained power source with connective wiring between the housings extending through a tubular conduit. Provisions are also made for coin actuation and timed use of the unit and the switching arrays permit the occupant to have the sole knowledge of the combination permitting access to the room without energizing the alarm circuit.

8 Claims, 5 Drawing Figures [76] Inventor: Claude E. Gordon, 4521 Blonigan Ave., Orlando, Fla. 32806 [22] Filed: June 19, 1972 l [21] Appl. No.: 264,034

[52] U.S. C1. 340/274, 317/134 [51] Int. Cl. G08b 13/22 [58] Field of Search 340/274, 276; 317/134 [56] References Cited UNITED STATES PATENTS 3,609,738 9/1971 Marte 340/274 3,553,673 1/1971 Fistell 340/280 3,450,953 6/1969 Gardner .1 317/134 3,544,987 12/1970 McMann..,. 340/274 3,058,092 10/1962 Johnson 340/274 UN X 3,234,516 2/1966 Miller 340/164 2,855,588 10/1958 Allen 3'17/134 X 3,024,452 3/1962 Leonard. 340/274 3,631,444 12/1971 Danie1....'. 340/274 Primary Examiner-John W. Caldwell Assistant Examiner-Scott F. Partridge Attorney, Agent, or Firm-Roger L. Martin '1 a ALARM SYSTEM BACKGROUND OF THE INVENTION This invention relates to alarm units and circuits for guarding closed areas adapted to accommodate people such'as hotel and motel rooms. The invention in particular has to do with alarm units and circuits that require the knowledge of a code or combination in order to disarm the alarm circuit and gain access to the closed area.

The use of key actuated door locks for guarding closed areas is gradually becoming outmoded because the keys can be duplicated and frequently fall into the hands of unscrupulous people who use the keys in the commission of criminal acts of thievery and the like. Because of this, many new living areas are being equipped with modern day locks which are released by the manipulation of devices that require knowledge of a predetermined code or combination. The use of such devices in the guarding of motel and hotel rooms and apartment areas having a frequent turnover of occupants is impractical because the codes and combinations have to be changed with each turnover in occupancy. Thiscreates excessive demands for expensive labor and when thecodes or combinations are known to people other than the occupants, there is the ever present possibility that the information will be used for illegal purposes to gain access to the closed area.

A general object of the invention is to provide improved alarm units and systems; for guarding closed ,areas. One particular object is to provide a practical alarm unit and circuit for guarding hotel and motel rooms having conventional key actuated door locking systems'and wherein thealarm unit can be disarmed with knowledge of a combination or a code which is solely under the control of the room occupant. Yet another object of the invention is to provide an alarm unit which can be readily mounted on a door of an entranceway without the need for major modifications in the structure at the entranceway area. Yet another object of the invention is to provide a simple, relatively inexpensive combination-type disarming circuit for a surveillance system and in which the combination can be readily changed. Other objects of the invention will become apparent from the description and disclosure which follows. I

Alarm circuits which embody the switching system contemplated herein for disarming the circuit have a suitable electrical power source and signaling device that are connected in series with the switching system and are also equipped with an intruder actuated switch that is closed to electrically connect the power source and signaling device when an intrusion is detected. The

- switching system has at least one switching circuit that cooperates in completing a conductive path between the terminals of the intruder actuated switch when the alarm circuit is armed and includes a plurality of parallel conductor circuits and a pair of circuit selector switches which serve to break the conductive path through the switching circuit when the same conductor circuit is selected by both selector switches of the switching circuit. One'of the circuit selector switches is designed to complete a conductive path across the switch with the conductor circuit selected while maintaining an open conductive path across the switch with respect to the other conductor circuits whereas the other circuit selector switch is designed to establish an open circuit across the switch with respect to the selected circuit while completing conductive paths with the other conductor circuits of the switching circuit. Thus, by manipulating one of the switches to select the circuit corresponding to the selection of the other switch, the conductive path through the switching circuit is opened. More than one switching circuit may be used in the switching system to provide branch switching circuits and which, of course, will raise the need for matching circuit selections in each branch switching circuit in order to disarm the alarm circuit.

The alarm unit is mounted on the door in the entranceway of the guarded area and has an audible signaling device which is energized when intrusion is detected by means of a DC battery component of the alarm circuit. This enables the alarm circuit to be packaged for simple installation on the door and without the need for extraneous connective wiring with the electrical power circuit available in the closed area. Such extraneous wiring, if exposed in the area, could of course be readily cut by contemplated intruders to disarm the alarm circuit before the intrusion unless major and expensive modifications in the entranceway areas are made to adequately shield the wiring in anticipation of such contingencies.

In the preferred embodiment of the invention the switching system is equipped with a plurality of parallel branch switching circuits and one of the conductor circuit selector switches of each branch is located at the exteriorsidc of the door while the other is located at the interior side of the door. This enables the room occupant by manipulation of the interiorly located switchesto establish the switching combination which must be matched by manipulation of the exteriorly located switches in order to disarm the alarm circuit and permit access to the closed area without energizing the audible signaling device. The simplicity of the alarm circuit lends itself to simple and effective packaging procedures which also enable the use of timing equipment and coin actuated devices that can be used in conjunction with the alarm circuit to provide an additional source of revenue for the proprietors of the guarded areas.

The novel features which'are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention, itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is an isometric view of a fragment of an entranceway area equipped with an alarm unit embodying the invention; I

FIG. 2 is an end elevational view at the lock or latch end of the door, as seen along the lines 2-2 of FIG. 1, with certain parts removed and other broken away;

FIG. 3 is a diagrammatic illustration of the alarm circuit components used in the unit shown in FIGS. 1 and FIG. 4 is a plan view of one type of switch component diagrammatically illustrated in FIG. 3; and

FIG. 5 is an enlarged sectional view showing along the lines 5-5 of FIG. 4.

' DETAILED DESCRIPTION OF THE INVENTION Reference is now made to the drawings and wherein on a door 11 in an entranceway 12 to a closed area. The unit includes a box-like hollow exterior metal housing 13 and box-like interior metal housing 14. A tubular conduit 15 is fixed to the back plate 16 of housing 13 and this conduit extends through a bore 17 in door 11. The conduit 15 is secured to the back plate 18 of housing 14 in a conventional manner as by means of a nut-type fastener.

Housing 13 provides a mounting for an array 19 of selector switch components of the switching system and which are manipulatable at the exterior side of the door. Housing 14 on the other hand provides a mounting for an array 20 of selector switch components of the switching system that are located and manipulatable at the inside of the door to establish the switching combination which must be matched by the exteriorly located switches in order to gain access to the closed area without actuating the alarm circuit. Conduit 15 serves to house the leads forming the conductor circuit which interconnect the exteriorly and interiorly located switch component of each branch switching circuit. The interiorly located housing 14 additionally serves to house an audible signaling device 21, an indicator light 22, a DC battery23, and the intruder actuated switch component 24 of the alarm circuit. Switch 24 maintains an open circuit condition when the door is closed for reasons of a magnet 25 that is mounted on the door frame 26 in close proximity to the switch location in the housing 14. Unit 10 is also equipped with a timer 27 and coin actuated linkage mechanism 28 and access to housing 14 for recovering the coins from mechanism 28 is gained through an accessway 30 in housing 14 and which is covered by a key locked plate component 31.

Reference is now made to the alarm circuit 32 shown in FIG. 3. The battery which provides the DC power source 23 for the circuit 32 is connected by lead 33 to one terminal of the intruder actuated switch 24. Switch 24 is a single pole, single throw switch and the other terminal 37 of switch 24 is connected to the horn or audible signaling device 21 as by lead 36. The pole piece is biased by a tension spring 38 to the closed circuit position in contact with contact 34. For reasons of the magnet 25, switch '24 is retained in an open circuit condition when the door is closed in the entranceway, as is illustrated in FIG. 3. Switch 24 is also equipped with a dash pot 39 which delays opening of the switch so that when the alarm is set off by opening the door the intruder cannot immediately deactivate the alarm circuit by simply closing the door. Instead, the dash pot delays movement of the pole piece under the influence of the magnet 25 and maintains an energized circuit condition for a predetermined period. The other side of battery 23'is connected by lead 40 in the illustrated embodiment to the wiper blade 41 of a timer switch 27. The arcuate contact 42 of timer 27 is connected by lead 43 through a resistor 44 to one terminal 62 of the switching system 45. The horn 21 on the other hand is connected by lead 46 to the other terminal 78 of the switching system. The indicator light is connected in parallel with resistor 44 by means of

line taps

47 and 48 in lead 43 as seen in FIG. 3.

r The switching system in the illustrated embodiment includes three branch switching circuits which are designated at 55, 56 and 57 and connected in parallel between the

terminals

62 and 78 of the switching system. Circuit includes a selector switch component 49 of the exterior array 19, a selector switch component 52 of the interior array 20 and a plurality of electrical leads designated at 58a and which form conductor circuits connectingswitches 49 and 52.

Branch switching circuits

56 and 57 are similar to circuit 55 and include

switches

50 and 51 of the external array 19, selector switches 53 and 54 of the internal array 20, and leads 58b and 580 that electrically interconnect the switch components of the respective parallel switching circuit.

The switching system depicted contemplates a three digit numerical selection in establishing the circuit combination which must be matched to disarm the alarm circuit and each of the selector switches 49 through 54 is equipped with 10 stationary electrical contacts that are numerically designated in FIG. 3 with digits ranging from zero to nine to represent corresponding referencing indicia viewable by the manipulator of the switching arrays. The numerically matching contacts of the pair of selector switches in each branch switching circuit are electrically connected by leads or conductors that provide the parallel circuit conductor branches 58a, 58b and 58c of the

branch switching circuits

55, 56 and 57.

The wiper blades 59, 60 and 61 of the exterior array of

switches

49, 50 and 51 are connected to one terminal 62 of the switching system by means of leads designated at 63, 64 and 65. Each of the wiper blades of

switches

49, 50 and 51 is manipulatable to conductively connect the selected conductor branch of its switching circuit with terminal 52 while isolating the other circuit branch from this terminal 62.

The structure of the open circuit selector switches 52, 53 and 54 is illustrated by the structure shown for switch 54 in FlGS. 4 and 5. Switch 54 has a stationary plastic disk 68 on which the stationary contacts 69 are fixed. Each of these contacts is electrically connected by one of the leads 58c to the numerically matching switch contacts of switch 51. Switch 54 has another disk 70 made of plastic insulating material and which has a suitable knob 71 that is mounted on top for rotatably manipulating the disk 70 with respect to disk 68. The underside of disk 70 is equipped with an arcuate metal contact 72 which is designed to contact all but one of the contacts 69 on disk 68, and has a cutout 70a with an adjacent arrow to indicate the conductor isolated from the, terminal 78 at the switch position. This arcuate switch contact 72 is electrically connected by a printed circuit lead 73 to a metal pin 74. Pin 74 establishes the axis of rotation for disk 70 and extends through a bore 75 in disk 70 and also through another bore 76 in disk 68. Bore 75 is lined with electrically conductive material that forms an extension of circuit lead 73 and maintains an electrical connection between pin 75 and contact 72 when disk 70 is rotated. Pin 74 is fixed to disk 68 by means of a pair of nuts 77 and is electrically connected to the other terminal 78 of the switching system by means of lead 79a. Switches 52 and 53 are connected by printed circuit leads 81 and 82 to the appropriate pins and from there by

leads

83 and 84 to the terminal 78 of the switching system.

Switches

52, 53 and 54 are manipulatable to isolate the selected conductor circuit of the branch switching circuit associated therewith from terminal 78 while nevertheless maintaining an electrically conductive path between this terminal 78 and the other conductor circuits of the branch. Accordingly, switches 52, 53

and 54 determine the conductor circuits which are open and by manipulating switch components 59, 60 and 61 to select the isolated conductor circuits in each branch switching circuit, the alarm circuit can be broken and disarmed so that closure of switch24 fails to energize the audible signaling device 21.

In the normal process of arming the alarm circuit 32 and selecting the combination which can be matched to gain access without energizing the circuit, the mechanical link between the wiper blade 41 and knob 29 is established by inserting a coin in the coin actuated linkage mechanism 28. Thereafter, knob 29 is rotated in the direction of arrow 87 until wiper blade 41 engages stop 85 and assumes the broken line position designated at 86. The circuit under such circumstances is incomplete and remains so for a predetermined time as the wiperblade 41 moves in the direction of arrow 87a and into contact with contact 42. This open circuit condition permits the occupant to select the combination and leave the closed area without energizing the alarm circuit and enables the alarm circuit to become automatically energized through the normal movement of wiper blade 41 into contact with switch contact 42.

After the timer is actuated the occupant through manipulation of

switches

52,53 and 54 can select an appropriate combination for usein gaining subsequent access to the closed areawithout energizing the alarm circuit. In FIG. 3, switches 52, 53 and 54 are shown in positions establishing the three digit numeral 147, as the combination and switches 49, 50 and 51 are shown in positions matching the combination so that all of the

branch circuits

55, 56 and 57 are broken between the terminals62 and 78. Accordingly, the occupant must manipulate one'or more of the

switches

49, 50 and 51 in order to establish a ready condition so that the alarm circuit will become armed when wiper blade 41 engages contact 42.

Assuming that the door is closed and that the switches of at leastone of the

branch circuits

55, 56 and 57 are mismatched, there is then an electrically conductive path between

terminals

62 and 78 and hence during the period that wiper blade 41 is in contact with switch contact 42 the alarm circuit 32 is armed and ready to detect anintruder. Thereafter if an intruder opens door 11 the pole piece 35 of switch 24 is drawn into contact with switch contact 34 by spring 38 and the alarm circuit is completed to energize the horn 21 and sound an audible signal. Similarly, indicator light 22 is energized under such circumstances to also provide a visual signal. Any attempt by the intruder to disarm the circuit as by quickly closing the door so that the pole piece 35 comes under the influence of magnet 25 is resisted for a predetermined period by dash pot 39.

On the other hand assuming that the door is closed and the alarm circuit is armed, the occupant can thereafter gain access to the closed area by manipulating the

switches

49, 50 and 51 to match the combination indicated by

switches

52, 53 and 54 so as to break the conductive pathsthrough the

branch circuits

55, 56 and 57 and thereby enabling access to the closed area without energizing the alarm circuit.

While only a certain. preferred embodiment of this modifications as fall within the true spirit and scope of this invention.

What is claimed as new and what it is desired to secure by letters Patent of the United States is:

1. An alarm circuit for guarding a closed area having an entranceway closed by a door comprising an audible signaling device, a DC power source, an open switch closed by opening the door in the entranceway and connected in series with said signaling device and said power source, and a switching system having a pair of terminals connected in series with the open switch and a switching circuit that establishes a conductive path between the terminals when the alarm circuit is armed; said switching circuit including a plurality of electrical conductors arranged in parallel, a first conductor circuit selector switch electrically connected to one of the terminals, and a second conductor circuit selector switch electrically connected to the other of the terminals; said first conductor circuit selector switch being manipulatable at one side of said door to simultaneously electrically connect a selected one of the electrical conductors with and isolate the others of the electrical conductors from said one of the terminals, and said second conductor circuit selector switch being manipulatable at the other side of said door to simultaneously isolate a selected one of the electrical conductors from and electrically connect the others of the electrical conductors with said other of the terminals.

2. An alarm circuit in accord with claim 1 where said switching system includes a plurality of such switching circuits connected in parallel branches between said terminals.

3. An alarm circuit in accord with claim 1 comprising means biasing the open switch toward a closed circuit position and magnetic means mounted at the entranceway to overcome the biasing means and retain the open switch in the open condition when the door is closed.

4. The combination of: a closed area having an entranceway and a door closing said entranceway, and an alarm unit mounted on said door; said unit including an alarm circuit comprising an audible signaling device, a DC power source, an open switch closed by opening said door in said entranceway and connected in series with said signaling device and said power source, a first housing mounted on the exterior side of the door, a second housing mounted on the interior side of the door, a conduit extending through the door and communicating with the first and second housings, and a switching system having a pair of terminals connected in series with said open switch and a switching circuit that establishes an electrically conductive path between the terminals when the alarm circuit is armed; said switching circuit including a plurality of electrical conductors extending through said conduit and arranged in parallel circuits, a first conductor circuit selector switch mounted on said first housing and electrically connected to one of the terminals, and a second conductor circuit selector switch mounted on said second housing and electrically connected to the other of the terminals; one of the first and second conductor selector switches being manipulatable on the housing associated therewith to simultaneously electrically connect a selected one of the electrical conductors with and isolate the others of the electrical conductors from the terminal connected thereto, the other of the first and second conductor selector switches being manipulatable on the housing associated therewith to simultaneously isolate a selectedone of the electrical'conductors from and electrically connect the others of the electrical conductors with the terminal connected thereto, and said signaling device and DC power source being mounted on said second housing,

5. The combination in accord with claim 4 where said switching system includes a plurality of such switching circuits connected in parallel branches between said terminals.

6. The combination in accord with claim 4 where said unit includes means biasing the open switch toward a closed circuit position, and magnetic means mounted at the entranceway to overcome the biasing means and retain the open switch in the open condition when the door is closed.

7. The combination in accord with claim 6 where the alarm circuit includes a timer switch connected in seties with the open switch and the terminals of said switching system, and means cooperating with said open switch to delay opening thereof under the influence of said magnetic means.

8. The combination of a closed area having an entranceway and a door closing said entranceway, and an alarm unit mounted on the door and having a first housing located at the exterior side of the door, a second housing located at the interior side of the door, and an alarm circuit that includes an audible signaling device and DC power source connected in series, an open switch closed by opening said door in said entranceway and connected in series with the signaling device, and a switching system having a pair of terminals connected in series with the open switch; said switching system being adapted to establish an electrically conductive path between the terminals when the alarm circuit is armed and including branch switching circuits, a first array of circuit selector switches mounted on the first housing, and a second array of circuit selector switches mounted on the second housing; said first and second array of switches being manipulatable at the exterior of the respective housings to cooperate in breaking said branch switching circuits to disarm said alarm circuit.

Claims

4. The combination of: a closed area having an entranceway and a door closing said entranceway, and an alarm unit mounted on said door; said unit including an alarm circuit comprising an audible signaling device, a DC power source, an open switch closed by opening said door in said entranceway and connected in series with said signaling device and said power source, a first housing mounted on the exterior side of the door, a second housing mounted on the interior side of the door, a conduit extending through the door and communicating with the first and second housings, and a switching system having a pair of terminals connected in series with said open switch and a switching circuit that establishes an electrically conductive path between the terminals when the alarm circuit is armed; said switching circuit including a plurality of electrical conductors extending through said conduit and arranged in parallel circuits, a first conductor circuit selector switch mounted on said first housing and electrically connected to one of the terminals, and a second conductor circuit selector switch mounted on said second housing and electrically connected to the other of the terminals; one of the first and second conductor selector switches being manipulatable on the housing associated therewith to simultaneously electrically connect a selected one of the electrical conductors with and isolate the others of the electrical conductors from the terminal connected thereto, the other of the first and second conductor selector switches being manipulatable on the housing associated therewith to simultaneously isolate a selected one of the electrical conductors from and electrically connect the others of the electrical conductors with the terminal connected thereto, and said signaling device and DC power source being mounted on said second housing.

7. The combination in accord with claim 6 where the alarm circuit includes a timer switch connected in series with the open switch and the terminals of said switching system, and means cooperating with said open switch to delay opening thereof under the influence of said magnetic means.