US1873499A - Lightning arrester - Google Patents

Description

23, 1932- A. G. STEINMAYER 1,873,499

LIGHTNING ARRESTER Filed July 5, 1928 K @MWM 0 A1Win Ejtrsmma EL 4! 1 y Patented Aug. 23, 1932 UNITED STATES PATENT OFFICE? PORATION OF DELAWARE Various types of lightning arresters have been designed for this purpose with varying degrees of success in operation but it has always been diflicult to design an arrester for such use which positively precluded the possibility of the are holding on after the surge which invariably destroys the entire device, and this invention, therefore, has as its primary object to provide a lightning arrester of the character described having means for which might positively rupturing any are the line volttend to hold on after a surge in age.

Another object of this invention resides in the provision of an improved lightnin arrester of the character described emb ying resistance units through which the current incident to a lightning discharge or a line voltage surge is conducted to the ground.

The use of resistance units or resistance elements in series with a lightning arrester of the characterdescribed is a known expedient for the reduction of current passing through the device but heretofore such resistance elements have been open to the objeotion that their resistance diminishes with the passage of current therethrough due to the excessive heat generated therein and this invention contemplates the use of resistance elements in connection with means whereby thetotal resistance -of the elements is increased rather than diminished upon the passage of current therethrou h.

And a more specific ob ect of this invention resides in the: provision of a pluralit of resistor discs arranged in pairs with t eir faces abutting and with separator units interposed between the pairs of resistor discs, the units being formed of two dish shaped bimetallic washer members which flatten when subjected to heat produced by the passage of current therethrough, to permit the dlscs to become separated from each other and thereb increase the resistance thereof.

Wit the above and other objects inview which will appear as the description proceeds, my invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the ap pended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

In the accompanying drawing,.I have illustrated one complete example of the physical embodiment of my invention constructed according to the best mode I have so far devised for the practical application of the principles thereof, and in which:

Figure l is a transverse, sectional view taken through a lightning arrester embodyin my invention; and

igure 2 is an enlarged, sectional view taken through one of the washer or separator units.

Referring now more particularly to the accompanying drawing, in which like numerals designate like parts throughout the several views, the numeral 5 designates a tubular housing or body member formed of insulating material preferably porcelain or the like, and having a plurality of petticoats 6. Adjacent the lower end of the body- 5 is an annular'recess 7 about which a supporting member, not shown, is engageable, to mount the structure in any suitable manner.

The body 5 has an aperture 8 extending longitudinally through the major portion of its length, the aperture being reduced at its lower portion to form a shoulder 9 and continuing outwardly therefrom in a taperingly enlarged aperture 10 at a medical part of which an annular recess 11 is formed.

Positioned in the aperture 8 and resting upon the shoulder 9 is a contactor disc 12 having a downward projection 13 with which a ground wire 14 is electrically connected, the projection 13 and a portion of the wire 14 being embedded in an insulating compound or cement '15 partially filling the aperture 10 and being retained against outward movement by the annular recess 11. Also positioned within the bore 8 above the contactor disc 12 is a plurality of resistance discs 16, one being placed directl above the contactor disc 12 and the remain er of the discs being arranged in pairs having their adjacent faces enga mg, and with separator units or washers l interposed between'the pairs of discs.

The washer members 1'? consist of a pair of substantially dish-shaped members 18 each formed of a oi-metallic metal and connected at their center by a rivet 19, as clearly illustrated in Figure 2. The position of the two metals forming the dish-shaped washer units 18 is such that when subjected to heat they cause the members 18 to flatten or approach each other, as illustrated in dotted lines in Figure 2.

Positioned above and in electrical engagement with the uppermost resistor disc 18 a hemispherical member 20 having annular flange 21 directed laterally from its edge. The member 20 is maintained in electrical engagement with the uppermost resistor disc by a tubular insulating member 22 positioned within the outer end of the bore 8 with its lower end engaging the annular flange 21 and held against outward movement by a cap member 23 threaded on a ring 24 secured.

on the adjacent end of the body member by being cemented or otherwise fixed thereto. The cap member 23 being threaded on the ring 24: permits any degree of pressure to be applied on the resistance element.

The hemispherical member 20 forms one terminal of a spark gap the other terminal of which is a second hemispherical member 25 fixed on one end of a threaded stud 26. The stud 26 is threaded in an aperture 27 in the cap member in axial alignment with the bore 8 and has a screw slot 28 in its outer end by which it may be threaded into and out of the cap member to adjust the position of the terminal 25 with respect to the terminal 20. The gap between the terminals 20 and 25 is adjusted to be just great enou h to prevent the normal voltage of the line iom jumping thereacross but permits any abnormal voltage surge to relieve itself to the ground across the gap.

A conductor terminal 29 is mounted on the outer end of the stud 26 and is impinged between the adjacent portion of the cap 23 and a nut 30 threaded on the stud, the terminal 29 having a conductor 31 in electrical connec tion therewith by which the contact 25 may be electrically connected with the line.

Normally, the total resistance of the element is substantially fixed and the resistor discs of each pair are maintained in engagement under pressure imposed by the separator units, but upon a surge in line volta e, the current jumps across the gap from t e terminal 25 to the terminal 20 and is conducted through the series of resistor discs and the bi-metallic separators to the ground through the ground wire 14. The passage of current through the resistor discs produces an excessive temperature rise which causes the bi-metallic members 18 comprising the washers or separators 17 to flatten or to move their l lxaripheries towards each other permitting t e resistor discs to separate, thus appreciably increasing the resistance of the entire device. I

As the separator units flatten the total height of the pile of discs and units decreases allowing the hemispherical member 20 to settle or move away from the other hemispherical member 25, thereb increasing the gap to further add to the resistance of the device.

Should the arc continue the hold on, the resistance of the device increases proportionally, eventually producing a series of gaps between the respective resistor discs thereby introducing an infinite resistance into the circuit.

From the foregoing description, taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the art to which an invention of this character appertains, that I have provided a lightning arrester for conducting a line voltage surge to the ground in which is incorporated a re sistance element, the resistance of which in creases upon passage of current therethrough whereby any abnormal surge in the line may be safely conducted to the ground without danger of the arrester being destroyed.

What I claim as my invention is:

1. In a lightning arrester of the character described, a plurality of resistance units, and means interposed between said units for tem porarily increasing the resistance thereof upon passage of current therethrough.

2. In a lightning arrester of the character described, a plurality of pairs of resistance units, and means interposed between the pairs of resistance units for maintaining the units in engagement under pressure, said means diminishing its pressure to increase the resistance of the units upon passage of current therethrough.

3. In a lightning arrester of the character described, a plurality of resistor discs arranged in pairs and bi-metallic members interposed between said pairs of resistor discs for increasing their resistance upon passage of current therethrough.

4. In a lightning arrester of the character described, a plurality of pairs of resistor discs arranged with their adjacent faces abutting and means interposed between said pairs 0t resistor discs for normally maintaining the same under pressure, said means decreasing the pressure upon passage of current therethrou h.

5. n a lightnin arrester of the character described, a lurality of pairs of resistor discs arranged with their adjacent faces abutting, and separator units interposed between said pairs of resistor discs and normally maintaining the resistor discs in engagement under pressure, said separator units being .formed of bi-metallic metal and substantially dish-shaped whereby the passage of current through the resistor discs and the separators causes the separators to flatten and diminish the pressure imposed on the resistor discs to increase the resistance thereof.

6. In a lightning arrester of the character described, a pair of terminals forming a gap across which a current jumps, a plurality of pairs of resistor discs, and separator units formed of dish-shaped bi-metallic members interposed between the pairs of discs to normally maintain said discs in engagement under pressure and against one terminal of the gap, the separator units flattening upon passage of current through the arrester thereby diminishing the pressure on the discs and increasing the gap between the terminals.

- 7. In a lightning arrester, an electrical resistor comprising a plurality of stacked resistance elements, and temperature responsive elements interposed between certain of the stacked resistance elements normally maintaining the resistance elements in a state of compression and operable to diminish the degree of pressure on the plurality of stacked elements upon the passage of electric current therethrough.

8. In alightning arrester, a plurality of stacked resistance units, and thermo responsive means interposed between certain of the resistance units and operable upon the passage of electric current therethrough to increase the total ohmic resistance of the stack of units.

9. In a lightning arrester, a plurality of electrical resistance units in stacked relation, and bi-metallic elements interposed between certain of the resistance units and operable upon the passage of electrical current therethrough to increase the total ohmic resistance of the stack of units.

10. In a lightning arrester, a plurality of stacked electrical resistance units, and bimetallic pressure members interposed between certain of the resistance units to normally maintain the stack of units in a state of compression and operable upon the passage of electric current therethrough to diminish the degree of compression of the stack of units and thereby increase the total ohmic resistance of the stack of units.

11. In a lightning arrester, the combination of aidielectric housing, and an electric resistor assembly comprising bodies of relatively high,

electrical resistance and thermo responsive means operable upon the passage of electric current therethrough to increase the effective resis ance of the resistor assembly, within the dielectric housing.

12. In a lightning arrester, the combination of a dielectric housing, and an electrical resistor assembly within the housing and comprising bodies of high electrical resistance and bi-metallic elements operable upon the passage of electric current therethrough to increase the total ohmic resistance of the resistor assembly.

13. In a lightning arrester, a pair of ter- .of a dielectric houslng, a pair of terminals ninals forming a gap across which current umps, one of said terminals being movable,

an electric resistor assembly in series with the gap and connected with the movable terminal, said resistor assembly comprising bodies of high electrical resistance in stacked relation and thermo responsive means normally maintaining one of the dimensions of the resistor assembly at a predetermined maximum and operable upon the passage of current therethrough to decrease said dimension and carry the movable terminal away from the other to increase the gap between the terminals.

14. In a lightning arrester a pair of terminals forming a gap across which current jumps, one of said terminals being movable toward and away from the other, an elec- .trical resistor in series with the terminals A and connected with the movable terminal so that one overall dimension of the resistor controls the position of the movable terminal with respect to the other terminal, and means for simultaneously increasing theohmic resistance of the resistor and decreasing its said dimension to carry the movable terminal away from the other upon the passage of current therethrough.

15. In a lightning arrester, the combination within the housing forming a gap across which current jumps, one of said terminals being movable toward and away from the other, an electrical resistor within the housing and supporting the movable tenninal, said resistor comprising a plurality of stacked bodies of high electrical resistance and thermo responsiveelements interposed between certain of the bodies of high resistance to normally maintain a predetermined degree of) contact pressure between the bodies of high resistance and operable upon the passage of electric current therethrough to diminish the degree of contact pressure and the total height of the resistor, whereby the movable terminal moves away from the other terminal to increase the gap.

In testimony whereof. I have hereunto aflixed my signature.

ALWIN G. STEINMAYER. 118

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