US2514807A - Portable electric fire alarm device - Google Patents

Description

July 11, 1950 w. M. SHAW PORTABLE ELECTRIC FIRE ALARM DEVICE Filed April 5, 194a I I A?? u 'INVENTOR. W/IL TERM SHAW BY 772- M ATTORNE Y. I

I: vr l is a firealarmdevicen the fire alarm device.

I vie Patented July 11, 1950 Walter MlShaw, Arkansas City,iKans; 7 Application April 5, 1948; Serial No: 191055.

; My invention relates. tota portable electric fire alarm devices The-:object of the invention is to z'oiai s. (01. 177-311 v plate l2 is-provided-withanupwardly extending stud l 4 1 that is centrally positioned thereon and provide a fire: alarm device that can be carried 'inza.travelerssuitcase or the like. v

Another object of the invention is to provide at-fire alarm "device1 of: the, kind mentioned that -can;;'- be'-'movedt fromv place to place so as to be located int-whatwould-be the rrnostadvantageous,

selectedalocation for thefire alarm .to-be located.

nn-further object. oftthe invention is to provide an -alarm device of the kind mentioned; that is l' small and compact so that it will not occupy I much space-in onesaluggage.

v A still further object on the device is to provide a fire alarm-of the kind. mentioned that is,

simple, sturdyin-construction, durable and long lived and, one thatwilllbe operated byincreases in temperature, above normal temperatures.

The

eand. other objects-will be more fully explained as this description progresses..

Nowreferringto the accompanying drawings v finvlhich 'similarnumeralslof reference designate the lsame parts throughoutthe several figures of the drawings,

detail'side elevationall view of the .i 2151a vertical sectional detail view through Fig 3; is a bottomzplanlview offth device, the

;view being as-xseenfrom the line III--III in.Fig., l. and lookingainlthe direction-of the arrows.

Fig Alisa: top plan view-of thedevice, the view being asrseeng from the IineIV- IV in Fig, land loolging in the direction of the arrows Fig.5 visa detail cross sectional-view of the device; the; view being as-seen from; theline V -V Lin.Fig. 2.-andlool;ing in the direction of v the ars-"L m; n1 Y i a r Eig'..6is;a cross sectional view of: the alarm de the views beings as seen fromzthe line VI-Vl.

in:=.Fig .,1 ,and looking in the direction of the ar- 7 In the drawings is shown a hollow cylindrical "shapedhous ngor casing l0, having a series of elongated vertically positioned andclo sely spaced together openings i I. in the: vertical wall l0 thereof, The housing. l0 is.-prefera-bly made of material] thatfisha nonconductor of electricity, 'S1l( )h; 9lSh3tl d\ rubber, fiber, pottery,. plastic material or the'like.

' lythreaded into-theclosure-plate i2. The closure hevupper end ofthecasing. 1-0 is-provided with a -metallictclosure plate 7 t2 that-isrigidly attached thereto by means'of screws I3=that passthrough --..the upper edge of-thecasing wall l0. and are may bema'de ash-an integral part thereof or may be attached thereto by means of screws l5 which a maypass'throughl-theplate l2'and are threaded intovthe: stud l4 to rigidly hold: thevstud M on the plate I2. I

An alarm bell lB-rests onthe upper endof the stud lfi-and is rigidly held bymeans of a screw I that passes-through the center thereof and is threaded into the upper end of the stud M. The bell; is substantially the samediameteri as the casing l0 andthelower edge of the bell is spaced a littleabovethe closure plate i2.on the closure plate] Z-andhoused withinthe ball [6 is astand- ;ard electric bell tapper; device comprising the electromagnetic coils l8 and HL-Vibrator plate 2 .0,;one end of-which is pivotally carried. on, an insulated pin 2| and on the other end of the plate 2Ulis rigidly mounted the belltapper arm :22 and tapper 23. The vibrator plate 20' is pro- 1 videdJwith a spring leaf element 24, one end of WhiCll'iS rigidly attached. to the vibrator plate 20 at agpoint adjacent the vpivotal mounting of the vibrator plate-2B on the pin 2|. Theother end of the leaf spring 24 is provided with an. electrical contact .point 25' that bears against an adjustableascrew contact element 26 that is carried on a bracket. 2.! thatis rigidly carried by the closure plate I2 and-is insulated therefrom. The vibrator plate Zll'i's. provided with a second leaf spring element 2%, one endv of, which is rigidly attached thereto at al pointv adjacent the pivotal mounting 2|, theother end of which bears against a pmza thatisrigidl'y carried on the closure plate '12 and is'insulated therefrom,lthe leaf spring 23 beingso tensioned as to rock the vibrator plate til outwardly, thereby causing the contact point '25 to stand in engagement against the end of the contact screw 26,, one end of the wire of the coil 19 connects with the metallic pin 29, against whichvthe spring 28 bears, the other end of the wire of the coil 19 connects with one end of the wire'of the coil IBand the other end of the wire of the coil 18 isgrounded or connects with the vclosure plate 12. r 7

Within the casing I0 is'a battery case or holder 30 that is preferably integrally formed thereon and. is provided withza pairof parallel andspaoed apart bores 3| and 32in which is slidably and removably positioned a pair of small dry cell electric batteries 33 and 34. The upper end of thecenter carbon element of the dry cell 33 bears "against one. endof a U-shaped spring leaf elementr35 the other end of which is rigidly held by and connected with the contact bracket 21 by means of a screw 36 which passes through the other end of the leaf spring and is threaded into the foot of the contact bracket 21, the leaf spring 35 and screw 36 being insulated from the plate l2.

The upper external metallic end of the second dry cell battery 34 bears against one end of a metallic L shaped leaf spring 31, the other end of which is positioned against the side wall of the battery holder element.

One end of a U-shaped bi-metal thermal element 38 rests against the second said end of the leaf spring element 31 and a screw 33 passes through the two engaging or contacting ends of the element 31 and 38 and is threaded into the body of the battery holder 30. The other leg of provided with an electric contact point 40 that is adapted to engage or contact a second contact point 4| that is carried on a metallic ear like element 42 that is an integral part of the metallic closure plate l2. The bi-metal thermal element 33 is positioned in close relationship to the one or more of the openings I so that it will be readily effected by heat around or in reasonably close proximity to the case ID.

The upper end of the movable leg of the bimetal thermal element 38 is provided with a piece of magnetic material such as soft iron 43 that is rigidly attached thereto and is in attractable relationship to a permanent magnet 44 that is rigidly carried on the lower end of the ear element 42. The magnet 44 is so positioned that when it attracts the magnetic element 43, the electric contact points 40 and 4| will contact each other before the magnetic material 43 will engage the magnet 44.

The casing I0 is provided with a bottom closure plate 45 that has spring clips 46 thereon, the upper ends of which are curved and will slide along the outer surface of the casing ID as the bottom 4-5 is advanced toward the case H! and as the bottom 45 engages the bottom edge of the case H), the upper ends of the spring clips 46 will sink into indentures in the outer face of the case l0 and serve as a means of detachably holding the bottom plate 45 on the case ID.

The upper face of the closure plate 45 is provided with a double ended leaf spring 41 the central portion of which is rigidly attached to the bottom plate 45 and when the bottom plate 45 is in place on the case H1, one end of the leaf spring 41 will engage the lower external metallic end surface of the dry cell battery 33 and the other end of the leaf spring I! will engage the lower end of the carbon center element of the dry cell battery 34.

The operation of the device is as follows. The free end of the bi-metal thermal element 38 normally stands so that the electric contact points 4i! and 4| are in a spaced apart position. Now if a fire occurs, the heat therefrom will pass through the case openings H and heat the bimetal thermal element 38, whereupon the upper end of the free leg 38 will slowly move toward the contact point 4| and as the two contact points come into close relationship with each other, the magnetic material will move into close relationship to the permanent magnet 44 and the attraction of the magnet 44 of the magnetic material 43 will be suiiiciently attracted by the magnet 44 and the contact points 40 and 4| will be brought into contact with each other with a snap action,

whereupon the electric circuit will be completed and the coils l8 and I9 will be magnetized and the vibrator plate 20, toward the cores of the coils l8 and I9, to a point where the contact points 25 and 26 will eventually separate, whereupon the coils I8 and I9 will be demagnetized and the spring 28 will rock the vibrator plate 20 outwardly, whereupon the tapper 23 will strike the bell and. ring it and simultaneously the contact points 25 and 26 will engage each other to again move the vibrator plate toward the cores of the coils l8 and I9, whereupon the foregoing described action will be repeated and the vibrator plate 20 will thereby assume a vibrating motion and the tapper 23 will be set into a vibrating motion to achieve a continual ringing of the alarm bell, While thedevice as shown in the drawings and described in the foregoing specification is probably the preferred form of the device it is to be understood that such modifications of the invention may be employed as lie within the scope of the appended claims without departing from the spirit of the invention. Now having fully shown and described my invention, what I claim is:

1. In a portable fire alarm device of the kind described; said device having in combination a casing, a demountable closure element for both the upper and lower ends of said casing, said closure element for the upper end of said casing having a bell and an electric bell ringing mechanism supported thereon, said casing having a battery holder therein, and carried thereby, said battery holder having a plurality of cylindrically shaped holes therethrough and in parallelism with and immediately adjacent each other, said holes being large enough to loosely receive and hold a dry cell battery, a thermostat for making and breaking an electric circuit, said thermostat being carried on said battery holder and adjacent the wall of the casing, said casing having openings therethrough to admit the passage of heated air through the casing to contact the thermostat for the operation thereof, a pair of battery contact elements, one end of the first of said contact elements being in contact with the stationary end of the thermostat leg and also rigidly supported on the battery holder, the other end of the first of said contact element being positioned over the adjacent battery holder opening and over the center axis of the said opening of the battery holder, the other of said contactelements by the said upper closure element and one end of the second said contact element being positioned over the other of said holes and over the center axis of the hole, a third contact element, said third contact element having two ends, and being carried by the said lower closure element and the ends of the third contact element being yieldably positioned one under each of said holes and over the center longitudinal axis of each hole, said casing having an electric circuit therein in which is included the bell ringing device, batteries carried by said battery holder and the thermostat for the control of said circuit.

2. In a portable electric fire alarm device of the kind described, said device having in combination a hollow casing having openings in the side thereof for the passage of heated air therethrough for operating the device, an upper and a lower closure plate for said casing, said plates being detachably attached one to each end of the casing, means in said casing and rigidly attached thereto for receiving batteries and holding the batteries in parallelism and spaced apart position, and with their ends exposed for contact purposes, said casing also having a thermostat controlled electric switch contained therein, an alarm bell and an electric bell ringing mechanism for ringing said alarm bell, said alarm bell and electric alarm bell ringing mechanism being carried on the said upper casing closure plate and outside the casing, said electric alarm bell ringing jmechanismbeing housed within the hollow of the bell, an electric circuit, said electric circuit fincluding batteries carried in the battery holder, said thermostat operated electric switch, electric alarm bell ringing device, and contact elements for contacting the tops and bottoms of the batteries to form a part of the electric circuit, the contact elements-for contacting the bottoms of the batteries being a yieldable element carried by the bottom closure plate for the casing and hav ing two ends positioned one under and contacting the lower ends of each of said batteries.

' WALTER M. SHAW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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