US9802A - Improvement in electro-magnetic alarms - Google Patents

Improvement in electro-magnetic alarms Download PDF


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US9802A US9802DA US9802A US 9802 A US9802 A US 9802A US 9802D A US9802D A US 9802DA US 9802 A US9802 A US 9802A
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    • G08B13/00Burglar, theft or intruder alarms
    • G08B13/02Mechanical actuation
    • G08B13/08Mechanical actuation by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind


Patented June 21,1853.
Specification forming part ofLetters Patent No. 9,802. datel June 21, 1853.
Te all whom it may concem:
Beit known that I, AUGUSTUS R. Porn, of Somerville, in the count of Middlesex and State of Massachusetts, have invented a new and useful or In proved Magnetic Alarm, to be applied to either a door or a window, or both, of a dwelling-house or other building,forthe purpose of giving an alarm in case of burglarious or other attempts to enter the same through said door or window by opening said door or window andi do hereby declare that the same is fully described and represented in the following spccification and the acconpanying drawin gs, letters, figures, and references thereof.
Uf the said drawings, Figure l represents an elevation of a door and window and my* apparatus as applied. th'ereto. Fig. 2 is a vertical and tran sverse seetio n taknthrongh the spring circuit-breaker to be hereinafter desoribed. Fig. 3 is a vertical section of the apparatus hereinai'ter termed the key as applied to the door. Fig. 4 is a section of the same as applied to the window.
In the said drawings, A represents a door, of which B is the frame, the same being shown a's fitted into the wall. D E and F are window-sashes of a window-frane, G. 5
H is an electro-magnet, fastened to the side of the wall in a convenient position, and having a bell, I, arranged over or near to it. One of the pole-wires leading from an electric hattery is seen atK. It extends to and winds around the magnet and passes upward over the *bell and window-treme, and thencc downward into the door-france, where itis connected to asmall stationarynetallic plate, L, as seen in the drawings. The plate L is fastened in the door-frame and forms a part of the appara-` tus which I term the key." The said key is otherwise composed of a netallie spring, M, one. end of which is made to bear against the plate L, while the other or, lower end is fastened to the door-frame,`the spring being fixed in a recess, N, made in the door-france.
. In Fig. 5 a transverse section of the doorframe is given, with the door represented as open. The inner edge of the door has a small stud or pin, O, projecting from it, which con stitutes a part of the key, and when the door is closed presses against the spring M. of the key and bears it away from contact with the plate l. As soouas the door is opene(l" avery short distance the stnd will be so moved away froin the spring as to allow the spring to come in contact with the plate L. From the lower part of the spring a wire, P, extends nearly to the lower pole of the magnet and toward and against What I term the spring circuitbreaker, which consists of a netallic spring, Q, eXtended npward from. the other battery-cirenit wire,lt.
To the magnet there is applied a movable pendulous armature, S, which vibrates on a pin, T, and has a hammer, U, extende'd upward from it and toward and within a short distance from the under side of 'the bell. When this hammer is at rest or down to its lowest position it is retained there by a stop-pin, V, against which the lower part of the armature of the magnet rests undersuch circumstances.
The form and shape of the circuit-break'er and its relative position with respect to the armature and the wireP thatleads from thesprn g of the key are in the drawings.
The top of the spring circuit-breaker is ormed with a small projection, n., which ex tends into part of the armature, so that when said armature is moved toward the magnet the projection of the circnit-breakcr will be struek by the arm so as to move the circuit-breaker out of contact with the end of the wire 1 The above constitutes the alarm apparatus as applied to a door. In the application of'it to a window the wire P or another wire, X, leading up fronit, may be 'extended into the window-frame and connected with the lower end of a netallic spring, I), arranged on the inside or pulley' stile of thefrane and made to bear against the edge of a sash, the said edge being so formed or shaped that while the window is in the act of being raised it shall press the spring toward and against the end of another. wire, Y, extended down from the wire KV before named, or is an extension of said wire when the apparatus is to be applied to a window alone. The spring-and contrivance for moving it, as above described, as applied to a window, constitute what Itern the keyfl The operation of the apparatns is as follows: While the door is closed or the window-sash down the magn'etic circuit is broken, because the spring of the key is thrown out of connection with the upper wire of the door or window framc; but as soon asthe door opened 'net becomes charged and draws the armature or the windowsash moved soasto allowthespring of- 'the key to come-into' contact with the npper wire or the metallic plate atthe lower end thereof, the circuit will be closed, the current of electricity being made toflow through the circuit-breaker and around the magnet. As soon as this takes place the mag-V succession of hlows of the hammer on the bell will be produced. I
my apparatus I dispense with the use ofj cIoek-workor an apparatus to ring; the bell through the agency of the falling of a weight or uncoiling of a spring, the hammer being kept in action on the bell whilethe battery contin- -ues to furnish electricity and the door or window is opem V I e1aim.-- For the purpose of rin gin g the bell, the combination of the movable or vibratin g armature and the'spring circuit-breaker with the hammer of the bell, the same to be used in eon'- neetion with the electro-magnet eircuit-wires and a key, as described, appled to a' door or` window, the wholeheng made to operate together substantially in manner and for the purpose as specified.
In 'testimonywhereof 1' have hereto set my signature this 27th dayof October, A. 111852. I AUGUSTUS lt. POPEQ witnesses: I
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3324245A (en) * 1963-04-04 1967-06-06 Harold T Stenhammar Ringing signal responsive, recording and control device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3324245A (en) * 1963-04-04 1967-06-06 Harold T Stenhammar Ringing signal responsive, recording and control device

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