US3114905A

US3114905A - Alarm system

Info

Publication number: US3114905A
Application number: US216496A
Authority: US
Inventors: Michael T Sliman
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-08-13
Filing date: 1962-08-13
Publication date: 1963-12-17
Anticipated expiration: 1980-12-17

Description

M. T. SLIMAN Dec. 17, 1963 ALARM SYSTEM 2 Sheets-Sheet 1 Filed Aug. 13, 1962 INVENTOR. Mama TJZ/MA/V BY W n m.

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ALARM SYSTEM Filed Aug. 13, 1962 2 Sheets-Sheet 2 17a 6 M P-1w? l2) k1} mmmfu,

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United States Patent 3,114,995 ALARM SYSTEM Michael T. Slimau, 826 W. Capitol Ave, West Sacramento, Calif. Filed Aug. 13, 1962, Ser. No. 216,496 Claims. (Cl. 340-280) This invention relates to an alarm system, and has as its primary object the provision of a means whereby the removal, or attempted removal of an electrical appliance such as a television set, a radio, a lamp, or any other normally connected electrical appliance, will cause a visual, audible, or other alarm to be actuated to indicate the potential removal of the appliance.

An additional object of the invention is the provision of an alarm of this character which may be concealed, or semi-concealed, in such manner as not to attract the attention of the potential thief and cause him to take steps to circumvent the alarm.

A further object of this invention is the provision of such an alarm which is contained within an electrical wallbox, and which is so arranged that tampering therewith to render the alarm inoperative is extremely difiicult.

Other objects reside in the combinations of elements, arrangements of parts, and features of construction.

Still other objects reside in the provision of a device of this character which is sturdy and durable in construc tion, reliable and eflicient in operation, and which is substantially automatic in operation and requires a minimum of moving parts.

In the drawings:

FIGURE 1 is a fragmentary partially schematic view of the wall of a room to be rented furnished showing the wallbox, and its connection with an alarm system.

FIGURE 2 is a vertical cross-sectional view of one form of outlet box embodying features of the instant invention.

FIGURE 3 is a plan view of the face plate of the outlet box taken substantially along the line 3-3 of FIG- URE 2 as viewed in the direction indicated by the arrows.

FIGURE 4 is a plan view of the face of the plug shown in FIGURE 2 taken substantially along the line 22 of FIGURE 2 as viewed in the direction indicated by the arrows.

FIGURE 5 is a fragmentary sectional View taken substantially along the line 5--5 of FIGURE 2 as viewed in the direction indicated by the arrows showing certain of the parts in a different position of adjustment.

FIGURE 6 is a view similar to FIGURE 2 but showing a slightly modified form of construction.

FIGURE 7 is a view similar to- FIGURE 3 taken sub stantially along the line 77 of FIGURE 6 but showing a modified form of construction.

FIGURE 8 is a view similar to FIGURE 4 taken substantially along the line 88 of FIGURE 6 and showing the construction of the plug of FIGURE 6; and

FIGURE 9 is a sectional view taken substantially along the line 9-9 of FIGURE 6 as viewed in the direction indicated by the arrows.

Similar reference characters refer to similar parts throughout the several views of the drawing.

Having reference now to the drawings in detail, and more particularly to FIGURE 1, there is generally indicated at 19 a wall of a room of the type which is rented furnished normally, such as a hotel room, a turnished room, a motel room or the like. The wall includes the usual facing behind which are the studs 1-1, and is provided with an electrical outlet box, generally indicated at 12, which is closed by a face plate 13 having a pair of female plugs therein as indicated at 14, the plugs being of the usual tw-o prong type and having a pair of slots 15, for the reception of the prong 16 of an associated male plug 17.

The face plate is connected to the usual electrical outlet box 18 in the usual manner by a screw 19, except that in accordance with the instant invention the screw 19 extends entirely through the box, and is constructed of magnetic or electrically conductive material, rather than the brass screw which is sometimes used in this connection. A pair of electrical wires 20 extends from suitable junctions 21 exteriorly of the box 18, and provide power for the appliance which is connected through plug 17 and cord 22 to the source of electricity.

The alarm of the instant invention comprises a fixed contact member 25 which is mounted on a supporting bracket 26 and a movable contact member 27 which is mounted on a spring arm 28.

Wires

29 and 30 extend from

contacts

25 and 27, and comprise a part of an electrical alarm circuit which is energized when the contact 27 is moved into engagement with the contact 25 in a manner to be more fully described hereinafiter. The wires 2? and 3t extend interiorly of the wall to an opening 31, and thence along the baseboard 32 and beneath the carpet 33 to a second opening 34, from which they extend to a suitable alarm box 35, which may be the telephone junction box, as described in my co-pending applieation Serial No. 216,495, filed concurrently herewith.

The arrangement is such that as long as the

contacts

27 and 25 are separated no alarm is actuated, but that promptly upon the engagement of contact 27 with contact 25, a suitable audible, visual, or other alarm is sounded either adjacent or in the room carrying the outlet box, or at a remote point such as a switchboard.

Contacts

27 and 25 are normally maintained in spaced relation by the normal resiliency of spring finger 28, unless closed by the dropping of a heavy magnetic metal weight 44 Weight 46 is contained in a vertical sleeve 41 which is secured by means of a strap 4-2 to the rear wall of outlet box I3, and is held in its uppermost position by means of a magnetic charge induced in steel or conductive metal screw 19. The charge in magnetic screw 19 is induced by a permanent magnet 43 which is contained in plug 17, plug 17 being normally of the three prong type, and the magnet 43 being inserted in place of the usual ground prong. In this illustrative embodiment of the invention the plug '17 is of such a shape that the magnet 43 directly engages the head of screw 19, and as long as magnetic force is applied through screw 19 the steel or other magnetic weight is retained in position against the screw 19, as shown in FIGURE 2. Removal of the plug 17, however, will immediately break the magnetic contact permitting weight 40 to drop forcing spring arm 28 downwardly and engaging contact 27 with contact 25 to close the circuit and actuate the alarm.

permanent magnet 45 is positioned so that the wire 46 contacts screw 19, and the force thereof is suflicient to raise weight 40 to its uppermost position.

FIGURES 6 to 9, inclusive, disclose a similar arrangement wherein a wall 10 contains an outlet box 12 having a face plate 13 and a pair of female plugs 14a, which may be, if desired, of the three prong variety, but which in any event are set farther apart than the corresponding plugs 14. Female plugs 14a are adapted to be engaged by a male plug 1711 which is provided with male prongs 16a adapted to be inserted in the slots 15a of the female plugs or sockets 14a. In this modification a magnetic screw 19a serves to hold the plugs in related assembly.

The interior mechanism of the box 12 is identical to that previously described, and in consequence identical reference numerals are employed for similar parts, with the exception of the screw 19a. When the screw 1% is magnetized, in a manner to be more fully described hereinafter, the weight 48) is held in contact therewith, and when the magnetic force is released, weight 4th drops to engage

contacts

27 and 25 exactly as in the previous modification.

However, in this form of the invention, because of the spacing of the female plugs 14a, or alternatively, because of the configuration of the three prong plug 17a, mounted magnet 43a is not aligned with screw 1901. In order, therefore, to achieve magnetization of the screw 19, and consequently, hold the weight 4%) in elevated position, a wire 50 is looped around the head of screw 1% and extended upwardly, as best shown in FIGURES 6 and 7, to a point where it will be readily contacted by the permanent magnet 43a. In this manner the screw 1% is magnetized, and the steel weight 40 is held closely thereagainst until plug 17a is removed for any unauthorized purpose.

From the foregoing it will now be seen that there is herein provided an improved alarm system which accomplishes all the objects of this invention, and others, including many advantages of great practical utility and commercial importance.

As many embodiments may be made of this inventive concept, and as many modifications may be made in the embodiments hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative, and not in a limiting sense.

Iclaim:

1. An alarm system for preventing the unauthorized removal of an electrical appliance, comprising a wall outlet box having a face plate, a magnetic screw securing said face plate to the box and extend therethrough, at least one female socket carried by said box, a fixed contact mounted on said box interiorly of the wall receptacle, a spring arm above said fixed contact, a movable contact on said spring arm, an alarm circuit actuable by engagement of said movable contact with said fixed contact, a

magnetic Weight normally supported above said spring arm, a male plug connected to an electrical appliance engageable in said female socket, magnetic means carried by said male plug, and means contacting said magnetic screw with said magnetic means when said male plug is inserted in said female plug to magnetize said screw, said screw contacting said weight to hold the same above said spring arm, whereby removal of said plug demagnetizes said screw to permit said weight to fall on said spring arm to close said circuit and actuate an alarm.

2. The structure of claim 1 wherein said magnetic means comprises a permanent magnet mounted in a three prong plug after removal of the ground prong thereof.

3. The structure of claim 2 wherein an open ended sleeve is secured to the rear of said outlet box directly above said spring arm and directly below the extending end of said screw, and said weight comprises an elongated cylindrical steel member vertically slidable in said sleeve.

4. The structure of claim 3 wherein said permanent magnet directly contacts the head of said screw to provide said means for contacting said screw with said magnetic means.

5. The structure of claim 3 wherein an extending mag netic wire is secured to the head of said screw exteriorly of said face plate and extends to a point in contact with said permanent magnet when said male plug is,inserted in said female plug to provide said means for contacting said screw with said magnetic means.

References Qited in the file of this patent UNITED STATES PATENTS 1,992,255 Swadener Feb. 26, 1935 2,234,982 Ross Mar. 18, 1941 2,298,313 Ross Oct. 13, 1942 2,573,920 McLeod Nov. 6, 1951 2,591,288 Pitchford Apr. 1, 1952 2,681,443 Caulk June 15, 1954 2,969,445 Mitchell Jan. 24, 1961

Claims

1. AN ALARM SYSTEM FOR PREVENTING THE UNAUTHORIZED REMOVAL OF AN ELECTRICAL APPLIANCE, COMPRISING A WALL OUTLET BOX HAVING A FACE PLATE, A MAGNETIC SCREW SECURING SAID FACE PLATE TO THE BOX AND EXTEND THERETHROUGH, AT LEAST ONE FEMALE SOCKET CARRIED BY SAID BOX, A FIXED CONTACT MOUNTED ON SAID BOX INTERIORLY OF THE WALL RECEPTACLE, A SPRING ARM ABOVE SAID FIXED CONTACT, A MOVABLE CONTACT ON SAID SPRING ARM, AN ALARM CIRCUIT ACTUABLE BY ENGAGEMENT OF SAID MOVABLE CONTACT WITH SAID FIXED CONTACT, A MAGNETIC WEIGHT NORMALLY SUPPORTED ABOVE SAID SPRING ARM, A MALE PLUG CONNECTED TO AN ELECTRICAL APPLIANCE ENGAGEABLE IN SAID FEMALE SOCKET, MAGNETIC MEANS CARRIED BY SAID MALE PLUG, AND MEANS CONTACTING SAID MAGNETIC SCREW WITH SAID MAGNETIC MEANS WHEN SAID MALE PLUG IS INSERTED IN SAID FEMALE PLUG TO MAGNETIZE SAID SCREW, SAID SCREW CONTACTING SAID WEIGHT TO HOLD THE SAME ABOVE SAID SPRING ARM, WHEREBY REMOVAL OF SAID PLUG DEMAGNETIZES SAID SCREW TO PERMIT SAID WEIGHT TO FALL ON SAID SPRING ARM TO CLOSE SAID CIRCUIT AND ACTUATE AN ALARM.