US2443232A

US2443232A - Electric fence

Info

Publication number: US2443232A
Application number: US510310A
Authority: US
Inventors: William F Fagen
Original assignee: Stewart Warner Corp
Current assignee: Stewart Warner Corp
Priority date: 1943-11-15
Filing date: 1943-11-15
Publication date: 1948-06-15
Anticipated expiration: 1965-06-15

Description

June 15, 1948. w. F. FAGEN ELECTRIC FENCE Filed NOV. l5, 1943 Patentecl June 15, 194i;

ELECTRIC. FENCE William F. Fagen, Chicago,- Ill.,-vv assigner-Wo Stewart-Warnerl Corporation,- Chicago, HIll.,.a corporation of Virginia Application November 15, 1943,.Serial No. :510,310

(Giese-10) 3 Claims.

The present invention relates to electric fences,

and particularly to apparatus for` automatically energizing or charging a fence to'produce'a shock Lwhen an animal contacts the' fence.

An `object of the present invention is to prvide .a new and improved electric fence `charging i:

apparatus wherein a voltage is applied tothe fence for a predetermined interval to produce a .shock when an animal contacts pthe fence.

A further object of the present invention `is to providea new and improved apparatus-of the characterv specified wherein a Acontrol voltage,

f preferably of low value, is'normally appliedto the fence and a change in voltage `occurring lwhen an animal conta-cts the fence is utilized to effect the operation of a relay to connect a source Vof provide a new and improved apparatusof the v character specified wherein the voltage Yapplied to the fence is an alternating current'voltagefand .maximum current flow through the fence is limited to a sale value.

Other objects and advantages of thepresent invention will become apparent from the ensuingdescription, in the course of which vreference is had. tothe accompanying drawing, thel single figure of `which vis a diagrammatic illustration of one-embodiment of the invention.

The fence charging apparatus is indicated gen- Y -frallynby reference character I0.

It is lpreferably adapted to be connected to alternating current voltage source through a plug connector I2 anda power switch I4. It has apair of output terminals I 6 and I8 connected to the fence which, inthe illustrated embodiment, comprises a Ybare conductive wire supported by a series of -fence 4posts 22 (only one of which has been shown) having insulators 24 actually supporting the wire.

The posts are placed inthe earth in-conven,

tionalmanner.' Terminal I6 is connected to'wire 2'0Land terminal I8 is connected to `earth'through a conductor 26.` It should be understoodfhoweven-that in some installations it is preferable touse two or more fence wires, onecorrespond-w Afromleaving or entering the premises.-

2 The fence-'charger-Izincludes-means providing a `'control -voltage `which is normally applied -to the fence, and means providing another-voltage adaptedto beA appliedv tothe fence toprovide a shocking impulse -whenanv animal. comes into contact with the fence. The control voltage, whichispreferably a relatively lowdirect current voltage (say-of about 300 volts) ris provided by a ful1=wave rectifier-including a tube 28, the yplates lof which are connected to the terminals of a secondary winding `of a transformer 32, the primary winding 34 of which is connected to the powerswich i4 through a pair of fuses 36. The tube 28- includes -alsoa filament supplied with current `from-another -secondary winding Elfi.A The filamentl ofA the rectifier tube, forming the positive-terminal of the control voltage, is connected throughV a ilterr--resistorito a conductor 42 leading-to the output terminal I6, which itvmay `be remembered isconnected-.to the lfence Wire 20: I The-negative side lof the control voltage is connected to the output terminal I8 and. to ground -througha conductor 441connectedto the Vcentertap-of transformer4 winding 30 anda conwtrolresstor AGI 'A iilte'rcondenser 48 is connected across conductors 42 and 44'and serves, with resistor 40,htovsmooth the direct current acontrol voltage `applied to thel fence.

Whenan animalcontacts the 'fence there is yan increase in 'current flow 4across -the control resistor =46= anda resulting .change in voltage `drop thereacross. This change in voltage is;utilized toeffect theconnectionof the shockfprovding voltage :source across .the fence'. for fa predetermined-length of. time. Theevoltage thus applied tothe -Eence is *suppliedv bya secondary Winding-50,fone-terminal of ywhich is .connected through conductor 42 to the fence Wire 2U and lthel other terminal of. which is Aadapted to be connected togroun'd. terminal I8 byv ,a switch 52 YformingY part ofv a relay-including a winding 54 adapted to be energized in-.a manner to bedescribed shortly." When therswitch v52 is closed, a circuit lis' completed

acrossconductors

56 and 58,!therebytoefect.the connection of secondary windingfdirectly across the..,fence wire and ground. f The :winding 50 .may be` constructed to produce an opencircuit .voltage of the order of several thousand volts. Y

Currentflimiting means arerprovided innorder tol'limit the current. .applied to the fence'to a .safe value.2v In' the .instant embodiment ther cur- Yrent limitingv :means includes a loose magnetic coupling of the vsecondarycwinding v5t tothe `pri- Lkmary winding f341'of. .the transformer. l This construction provides what is essentially a constant current transformer, i. e., the secondary winding EU is the secondary Winding of a constant current transformer. The -coupling is so adjusted as to limit the maximum current to the desired value.

The relay 54 is energized in response to contact between the animal and the fence by means responsive to a change in voltage across the control resistor 45. This means includes preferably a cold cathode gas discharge tube 60 operated just below its breakdown point. Voltage is supplied to the tube from the rectier tube through resistors t2 and S4, and the relay, Winding. When the flow of current through resistor 46 increases, the ground end of resistor 46 becomes more positive and this positive potential is applied to the positive terminal of the tube through a resistor 66 and a condenser E8, the purpose of which is to prevent the breakdown of the tube in response to slow changes in current flow, such as might be caused by rainfall or the like.

,change in voltage across resistor 45. The inductance and resistor 64 aid in preventing the control impulse from being applied elsewhere than across the tube. Resistor 64 serves primarily to govern the time that relay 54 is maintained in its operated condition. y

Once therelay is energized, it remains energized for arti-me that is predetermined by the values of the previously referred to resistor 6,2 and a condenser lll connected between conductor 44 and the junction of

resistors

62 and 64. The time interval during which the relay is energized and the shocking voltage is applied to the fence is preferably adjusted to conform to codes governing the construction and operation of Yapparatus of this character. Y u,

Reviewing briefly the operation of the apparatus, itis assumed first that the switch I4 has been yclosedlto place they apparatus in operation. Un-

der normal conditions, i. e., when there is no contact between the fence and an animal, the relay 54 is deenergized, switch 52 Ais opened so that the only voltage applied to the fence is the relatively Vlow direct current control voltage, and the voltage across tube 6U is just below the breakdown voltage of the tube. v

vWhen an animalcomes .into contact with the fence, the flow of current through resistorA 46 increases to increase the voltage drop ,thereacross The change in voltage drop across resistor-46 is sufciently rapid so that a portion of it is applied across the tube through the condenser 68 and results in the breakdown of tube 60, which, it ymay be remembered, is operated just below its breakdown point. When the tube breaks down the condenser 'l' discharges through the resistor 64, which is a current limiting resistor, the relay winding, and tube 60. The ,relay` remains energized for a length ofv time determined by the val-v -ues of the condenser 10, resistor 62 through which the condenser is charged, resistor 64 and the electrical constants of relay 54. Upon energization of the relay the switch 52 is closed,and upon ldeenergization of the relay the switch is opened.

Whenthe relay 54 is energized the voltage appearing across the secondary winding 50 is applied across the fence to provide the desired shocking impulse.V Once the relay has been operated, i. e., closed and opened, it'cannotbe energized for a definite time interval controlled largely by resistor 62 and condenser l0, and furthermore, no succeeding impulse occurs unless there is a further change in current iiow through resistor 46, as by a second animal coming into contact with the fence or the rst animal again coming into contact with the fence after having disengaged itself therefrom.

While ,the condenser 48 is connected to the fence, it does not produce any substantial shocking effect when the fence is contacted by an animal because of the magnitude of control resistor 46, which may have a value of about .1 megohm.

While a preferred embodiment of the invention has been described in detail, many modications ,may be made without departing from the spirit of the invention, and I do not wish to lbe limited to the details of construction set forth, but desire to avail myself of all changes within the scope ofthe appended claims.

Having thus described rny invention, what I claimas new and desire to secure by `Letters'Patent'of the United States is:

1. Apparatus for energizing afence comprising a conductive wire adapted to complete a circuit through the body of an animal contacting the wire, including in combination, a sourceof voltage normally disconnected from the fence circuit, means including an electron tube and a re-Q lay having a winding in series with said tube controlled in response to contact between an animal and said wire foi-,connecting said voltage source to the fence circuit, and meansincluding a condenser adapted to discharge through said tube and relay winding for maintaining said connection for a predetermined length of time.

2. Apparatus for energizing a fence comprising a conductive wire adapted to complete a circuit through the body of an animal contacting the'wire, including in combination, a high voltage source of voltage normally disconnected from the fence circuit, means supplying said fence with a low control voltage, means' including a low voltage vsource of voltage, an electron tube associated with said second low voltagesource and a relay having a winding inv series with said tube controlled in response to a change in current ow through the fence wire occurring upon `'contact between an animal and said wire' for connecting said high voltage 'source to :the fence circuit, and means including a condenser adapted to discharge through said tube 'and' relay winding for maintaining said connection` for ya predetermined length of time. y Y u Y y 3. Apparatus for energizing a fence comprising a conductive wire adapted to` complete a circuit through the body of an animalcontacting the wire, including in com'binatior1,`al high supplying said `fence with a low control voltage,

`means including a low voltage source of voltage,

a cold cathode gas tube 'connected to saidlow voltage source and normally suppliedjwith a voltage slightly below its breakdown voltage and a relay having a winding in series with said tube controlled in response to'l a change in Acurrent iiow through the fence wireoccurring upon contact between an animal and said wire for connecting 4said high voltage source to `the fence circuit, saidV last mentionedV means including means for effecting breakdown of said tube, and means including a condenser in circuit Vwithvsaid relay and tube and normally chargedby said' low voltage sourceuand adaptedto discharge through said tube and relay winding up'on breakdown of Name Date Pfanstiehl July 15, 1941 Agnew et al Apr. 13, 1943 Roach Mair 11, 1943 Agnew NOV. 2, 1943 Klumb Mar. 7, 1944 FOREIGN PATENTS Country Date Australia Nov. 8, 1939 OTHER REFERENCES Agricultural Engineering, vol. 20, No. 1, January 1939, page '7, paragraphs 1 and 2.

Certificate of Correction Patent No. 2,443,232. June 15, 194s.

WILLIAM F. FAGEN It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Column 1, line 24, forsale read safe; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 31st day of August, A. D. 1948.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

Certificate of Correction Patent No. 2,443,232. June 15, 1948.

WILLIAM F. FAGEN It is hereby certied that error appears in the printed specification of the above numbered patent requiring correction es follows: Column 1, line 24, forsale read safe; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 31st day of August, A. D. 1948.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.