US1574587A - Protective device - Google Patents

Description

Feb. 23 1926.

N. A. LOUGEE PROTECTIVE DEVICE Original Filed Feb. '7, 1918 .7 Hr e zwwm m to t T A VA \\\\\\\\\\\0 I Q m 1 U4 w b m N WV @L M w v l atented Feb. 23, 1926.

UNITED STATES PATENT OFFICE.

NORMAN A. LOUGEE, OF SOHENECTADY, NEW YORK, ASSIGNOR TO GENEBAL ELECTRIC COMPANY, CORPORATION OF NEW YORK.

PROTECTIVE DEVICE.

Application filed February 7, 1918, Serial No. 215,796. Renewed November 24, 1823. i

T all whom it may concern:

Be it known that I, NORMAN A. Loosen, a citizen of the United States, residing at Schenectady, county of Schenectady, State of N ew York, have invented certain new and. useful Improvements in Protective Devices, of which the following is a specification.

My invention relates to protective devices and especially to lightning arr-esters and similar devices which are .operative to remove abnormal potentials, surges and similar discharges from an electric conductor.

The object of my invention is to provide a simple and durable lightning arrester of the type which is operative to permit a free discharge of electricity as long as the difference of potentialbetween the terminals of the device exceeds a' predetermined. amount but will interrupt the discharge the instant the difference of potential becomes normal.

More particularly the object of my invention is to provide an arrester of this type which is of unit construction, each arrester comprising a plurality of discharge units, any

number of which may be easily and quickly assembled to provide a composite arrester for the protection of a conductor under any operating voltage and in general provide an arrester which is an improvement on that covered by the U. S. Patent 1,238,660, granted to Crosby Field Frank.

The novel features which I believe to be characteristic of my invention will be definitely indicated in the claims appended her-c to, while the features of construction and the method of operation will be understood by reference to the following description taken in connection with the accompanying drawing which shows the preferred embodiment of my invention and in which Figure 1 is a side elevation of a protective device embodyin my invention; Fig. 2 is a sectional View o one of the discharge units comprising my protective device, and Fig. 3 is a perspective view of a discharge unit with one electrode removed.

My protective device is of unitary con struction, as shown in Fig. 1 and comprises a plurality of discharge units or cells 1, assembled one above the other in stack formation, the number of cells depending on the voltage of the conductor to be protected. It is understood that instead of mounting the units one above the other, these units may be mounted side by side if desired. Each discharge unit 1, comprises two conducting plates or electrodes 2 and 3, separated by an insulating spacer or member 4:, which engages the edges of the electrodes to form therebetween a closed chamber or com artment. In the preferred embodiment 0 my invention, the insulating spacer 4 is circular or ring-shaped in configuration and provided with a recessed outer edge 5, as best shown in Fig. 2. This outer edge 5 is preferably glazed to prevent accumulation of .dust or other foreign particles. The electrode members 2 and 3 are also preferably in the form of circular plates or discs, but it is understood that the spacing member and electrodes mayd have any convenient configuration -desire The electrodes 2 and 3 are secured to the insulating spacer member or ring 4 and integrally related therewith, in any suitable manner, but in the preferred construction I provide the integral relation by crimping or spinning the plate electrodes over the recessed edge 5 of the spaci member 4, as best shown in Fig. 2, to fbrm thereby a water-tight and weather-proof unit. In order to insure a tight joint between the plates and the spacing member 4:, I provide a washer or gasket member 6. between the plates 2 and 3 and the spacer 4. This gas ket'member 6 conforms with the configuration of the spacer 4 and in the construction shown, consists of a thin annular ring preferably of paper impregated with varnish or other suitable material. The electrodes 2 and 3 may be made -of brass or other noncoating process known as sherardizing and v set forth in U. S. patent to Collins and* Capp, No. 1,169,529, January 25, 1916.

\Vithin the compartment or chamber formed between the electrodes 2 and 3 is a filler 7 composed wholly or'in part of lead peroxide and preferably in the form of a powder which constitutes the discharge path between the electrodes. In order to concentrate to a restricted area, the energy of a discharge from the electrodes to the filler 7, I provide between the surface of the filler and either or both the electrodes, a thin insulating layer or film 8, which I preferably lead peroxide, and then spinning t means, to uprig t supportin washed, after which they are dipped 1n a solution ,of varnish to provide an insulating film of even thickness on both sides of the plates. The discharge units are then assembled by spinning or suitable crimping on one of the plates or. electrodes to the spacer member 4 with its gasket member 6,

with

e remaining electrode on the spacer 4 with its gasket member. The assembled and integrally related units are finally sand blasted to remove the varnish film from the outer filling thespace within the spacer ring or surface portions of both electrodes 2 and.

As best shown in Fig. 1, a protective device for the protection of a conductor opcrating under any voltage may beobtained by merely assembling the required number of units 1, these units being simply mounted with their electrodes 2 and 3 in surface or contact engagement, preferably one on to of the other to form a stack. If a consi erable number of these units are required, I maintain the stack rigid and enable the building up of the arrester to any height desired, by placing metal or conducting platesv 9 at suitable intervals between the units and securin these plates, bysuitable 10 of wood or other ins ating' material which are, in turn secured to base and to members 11 and 12 respectively. ith this preferred construction, I am 'able to s ace the upright mem bers 10 away from t e cellstack to permit more cooling action. It is understood, however, that in some cases I may do away with the plates 9 and arrange the upright members 10 to engage the outer edges of the units to form a supporting means or rack for the stack.

1 The base and top members are preferably of conducting material and serve as termi-- nals for the arrester, the base -member 11 being adapted to be connected to round. The top plate or terminal 12 may connected directly to the conductor to'be protected, bntin the preferred construction I 7 connect the terminal to the conductor through an adjustable spark gap comprising an arcing electrode 13, which is in conductive relation' with the terminal member and carried therebcy members and a cooperating. arcing electrode 14 a apted to be connected to the conductor and a so supportedby the terminal member 12 but insulated therefrom.

-Mounted upon the upright members 10 are protecting or petticoat members 15 whic serve to protect the cell units from weather conditions. Each petticoat may be of unitar construction, but in the preferred constructlon these petticoats comprise a plurality of similar shaped portions which are secured together and to each pair of upright members 10. There is also provided a hood member 16 supported by the top member 12 whichcooperates with the petrotect the cell units course, it is under ticoat members 15 to from the weather. 0

stood that the petticoat members 15 and protecting hood 16 are used onl on the outdoor type of arrester, the in oor type having these members removed.

Theioperation of my protective device .may be'briefiy described as follows: When abnormal voltage conditions occur on the conductor to be protected sufficient to discharge across the gap comprising arcing electrodes 13-and 14:, a path of low resistance trode l3' tothe top member or terminal 12, and then by electrode 2 of the top unit through its filler 7 to electrode 3 and thence to electrode 2 of .the next adjacent unit which is in contact engagement with the electrode 3 of the unit above and in the same manner through the plurality of units in series comprising the stack and finally to base member or terminal '11 and thence to ground. Due to the insulating film 8 on the electrodes, the. energy of the discharge is concentrated on, a limited .areaof the electrode' and as the'lead peroxide comprising is provided to'ground from the arcing electhe filler and discharge path through each unit is'a poor conductor of heat, a discharge causes, at the point of dischar e, a very local and very intense heating w ich instantly changes a very small amount of the lead peroxide into a. lower oxideo flead having a very high electrical resistance. As a result of this great'change in' the electrical resistance of that art of the filler comprising the ath of d1scharge,-a small mass of substantially non-conducting material instantly forms in the ath of discharge sufii-- cient to prevent furt er flow of current at that point. In this manner the arrester permits a ready and quickdischarge of current from the conductor and automatically cuts off the current after the discharge has passed to ground. The gas liberated by'the reductionof the high leadoxide finds its way out of the units at points between the conducting plates and the spacers-4. A second dis charge may occur at some other point on the electrodes converting the low resistance lead peroxide to a high resistance lower oxide to cut oil. the current. As the area of the dis-.

charge is very small, the electrodes are of suflicient area to permitia great'number of discharges to occur before the units need to be renewed. In view of the fact that the quantity of high resistance oxide formed at the time the arrester cuts off the dynamic current will, in many instances, depend upon the voltage of the dynamic current, the resistancewhich the mass of oxide formed by the discharge will offer to a second dis= charge will also be dependent upon the voltage of the dynamic current. As this resistance may not be sufficient to prevent a second discharge, due to high potential impressed across the unit, such second discharge may follow practically the same path through the unitas the first discharge.

With the units of the arrester of the construction described, such units can be easily and quickly assembled and kept in stock without fear of deterioration and when it is desired to assemble an arrester, it is only i necessary to place therequisite number of units one on top'of the other in the supporting structure, or with equal facility an arrester may be disassembled and old units replaced with new ones.

In accordance withthe provisions of the patent statutes, I have described the princi 1e of operation ofmy invention, together with the apparatus which I now consider to represent the bestembodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and

that the invention can be carried out by other means. 7

.What I claim as new and desire to secure by Letters Patent of the United States, 1s,-

1. A protective unit comprising a pairof conducting plates, aninsulatmg means be-.

.material within said chamber having 'low electrical resistance andadapted to be converted' into a material of high electrical re ,sistanceby the passage of an electric .dis-' charge thercthrough, and an insulating film upon the inner surface-of one of said plates adapted to break down locally to permit a local dischar' e throu h said material, the

' arrangement eing sue that said conductive plates constitute the electrodes which conduct current into the unit whereby a plate may either engage a suitable conductive support or support and make electrical contact with another unit.

2. .A protective. device comprising two electrodes, means for s acing the same apart and insulating them rom one another, one of said electrodes having a conductive 0on tact surface designed to make electrical con- ..tact with a suitable support and the other of spacing the electrodes apart and insulating them from one another, one of said electrodes forming a portion of the walls of said con-- tainer and arranged to constitute means whereby said.- device may rest against and thus be electrically connected to a suitable support, and material between said electrodes of low electrical resistance, said material being adapted to be converted into material of high electrical resistance by the passage of an electric discharge therethrough.

4. A protective device comprising two parallel plate electrodes, an insulating spacer between said electrodes, said electrodes .being interlocked with said spacer,

and a filler containing lead peroxide between V said electrodes.

5. A protective device comprising a receptacle having a side wall of insulating material, electrodes interlocked with said insulating side wall to form ends for said'receptacle, and a filler composed of material having low electrical resistance,-which material is adapted to be locally converted by heat into a material of high resistance.

6. A rotective device comprising a spacer o insulating material, metal plates cooperating with said spacer to form a receptacle 'and mechanically interlocked at their edges with said spacer so as to be insulated rom each other, each of said plateshavin face t erect, and a filler between the plates composed of fluent material having a low resistance and adapted to be changed locally by heat to material of high resistance.

7. A rotective device comprising parallel vmetal p ates each having an insulating film on its inner surface, a spacer of vitreous ma-- terial having a groove in the outer edge. i

lates being crimped into said groove to said plate:

yielding packing between said plates and said spacer, the edges of said tosaid. spacer, and a .filler between said "plates formed of material having low electrical resistance, which material is adapted to be quickly converted locally into a material of high resistance by an electrical discharge therethrough.

8. A protective device comprising a receptacle with aside wall of porcelain havan insulating film on the inner sur- I ing a groove in the outer edge, metal end walls with their edges crim ed into the groove in the porcelain side wa l to interlock the end walls and the porcelain side wall to form a unitary receptacle, each metal end wall having an insulating film on its inner surface only, a gasket between each electrode and said side Walls, and a fillercontaining lead peroxide for said receptacle.

9. A protective device comprising a plurality of disc units, each comprising two parallel disc electrodes separated by an insulating spacer interlocked with said electrodes and a filler containing lead peroxide between said electrodes, each electrode having a conducting outer surface and an in sulating film on an inner surface,-said units being mounted in a cylindrical stack'with their outer surfaces in electrical contact.

10. A protective device comprising a plurality of disc units each comprising two disc electrodes separated by a spacer and having between them a filler containing lead peroxide, said units being mounted to form a cylindrical stack, a metal plate interleaved between two of said units at an intermediate point of the stack to support the units above said plate and an insulating support for said plate.

11. A discharge unit for a protective device comprising an insulating ring having a recessed outer edge, conducting members on each side of said ring crimped overthe edges thereof to form an integral-structure, a filler containing lead peroxide between said mem bers, and an insulating film between said filler and said members.

12. A protective device comprising a plurality of separate discharge units, each unit comprising cooperating plate electrodes, and

' a filling between said electrodes containing lead peroxide, said units being assembled with their electrodes adjacent and in electrical connection, supporting means for said units, and conducting members mounted at intervals between said units operative to hold said units in alignment.

' 13. A protective device comprising a. plurality of separate discharge units, each unit comprising a spacer of insulating material and a pair of conductive plates individually secured to said spacer, and a filling between said electrodes containing lead peroxide, said units being assembled with their electrodes in electrical connection, a supporting structure for said units including members spaced longitudinally from the edges of said units, and conductive means carried by said members for maintaining said units in alignment. 1

14. A protective device comprising a plurality of separate discharge units arranged in alignment, each unit comprising a spacer of insulating material and a pair of conductive plates individually secured to said spacer, and a filling between said electrodes containing lead peroxide, said units being assembled with their electrodes in electrical connection, a supporting structure for said units including supporting members arranged alongside said units and spaced therefrom, conductive means carried by said supporting members for maintaining said units in alignment, and petticoat members spaced along and secured to said supporting members to protect said units from the weather.

15. In a device of the character described, a series of protective units arranged in a pile and means for protecting said units rom the weather comprising a series of spaced overlapping petticoat members surrounding said pile of units.

16. In a device of the character described, a series of protective units arranged one above the other, a plurality of overlapping, spaced petticoat members for shielding said units from the weather, and a plurality of upright members for holding said units and said petticoat members in proper alinement. 17. In a device of the character described, a plurality of similar protective units stacked one above the other in a column, a plurality of upright insulation members for maintaining said column rigid, a plurality of spaced overlapping petticoat members surrounding said column and secured to said upright members and a cap covering the top of said column.

In witness whereof, I have hereunto set my hand this 5th day of February, 1918. NORMAN A. LOUGEE.

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