US1494334A - Lightning arrester - Google Patents

Description

May 20. 1924.

. 1,494.334 A. E. BEATTIE LIGI iTNIRG ARI-(ESTER Filed Aug. 14. 1923 ATTY.

line side and bears a block Patented May 2t), 1924.

UNITED STATES PATENT OFFICE.

ARTHUR ELLIOT BEA'ITIE, 0F MANZANILLO, CUBA.

LIGHTNING ARRES'IER.

Application filed August 14, 1923.

5 Islands, have invented new and useful Improvements in Lightning Arresters, of which the following is a specification.

This invention relates to devices for earthing the line of a telephone, telegraph or the like instrument, in the event of lightning or an excessive electric potential occurring in the line.

The invention is illustrated on the accompanying drawing in conjunction with an earthing switch. In this drawing Fig. 1 shows a device with a primary magnet winding on each side of the pro tected instrument.

Fig. 2 shows a device in which both of two primary magnet windings are on the of the instrument, and

Fig. 3 shows a device in which a single primary magnet winding only is provided, on the line side of the instrument.

Fig. 4 is a diagrammatic side elevation ofthe sparking terminals.

Referring more particularly to Fig. 1; a is the telephone line, which is connected to one primary winding 1) of a horse-shoe electro-magnet, and thence to the telephone instrument 0. The other side of the instrument 0 is connected to the other primary winding d of the magnet, the other side of which is connected to an earthed block e.

f is an armature adjacent to the poles of the magnet and to which the line a is connected by a lead 9. This armature f normally tends to assume the position shown. it, which, on attraction of the armature f by the magnet, makes contact with the earthed block e, thus directly earthing the line a in shunt with the instrument 0 and the magnet windings d and b, when the latter are traversed by a current of excessive strength, stronger than the normal working current.

The instrument is shunted by a non-inductive resistance 2', which permits passage of an alternating current such as might not traverse the windings of the instrument 0, thereby maintaining the circuit through the magnet windings b, d for a sufiicient interval of time for the armature f to be attracted and directly earth the line. In addition the Serial No. 657,352.

non-inductive resistance shunt z' tendsalso to 55 protect the instrument 0 by providing an alternative path for the current. v

j is an earthed block so situated that it is contacted by the armature block it, on the rebound from the magnet when the latter becomes de-energized, or, conceivably, should the armature be repelled, instead of attracted by the magnet.

Now as the discharge of an atmospherically electrically charged line is oscillatory,

the inductance of the primary windings, b, d

of the magnet opposes a choking effect 'to the passage of the current and may not develop, even with a high potential, suflicient attraction to displace the armature.

To overcome or reduce such effect, a secondary winding 7:, Z is provided around each primary winding 6, d. These secondary windings k, l absorb energy from the primary windings and permit sufficient current to flow therein to generate a mag netic field of sufiicient intensity to displace the ear-thing armature f.

The arrangement shown in Fig. 2 diflfers from that of Fig. 1 only in both the primary windings Z), (Z of the electro magnet being arranged on the line side of the instrument.

In Fig. 3 there is only one primary winding Z), with its secondary la, and this 1s arranged on the line side of the instrument.

The secondary windings is, Z are connected in series with terminal plates m, a.

These plates m, n are so close together and the secondary windings k, Z are of such step-up ratio relatively to the primary windings b, d that sparking readily occurs across the gap between the plates m, n, when the primary windings b, d are traversed an alternating current of excessive potentlal.

The gap between the plates m, n intersects a spark gap between sparking plates 0, 7) in series in a direct connection (7 of the line a to earth.

Hence on passage of an excessive discharge through the primary windings b, d, a spark will be generated by the secondary windings 70, Z between the plates m, n, and such spark will ionize the gap between the plates 0, p and permit a spark to pass between them at a potential considerably below that necessary to cause a spark normally to pass. The line a will therefore be earthed f acquire such polarity as to choking v by the shunt q simultaneously'with or prior 2t! said earthed spark gap.

st1uments,"an "electro-magnetic earthi-ng E'step-up' secondary winding of said switch,

and, in series with said secondary winding,

spark" terminals in ionizing proximity to said earthed spark-gap.

-2. 'In*af lightningarre'ster for electrical instruments, a primary winding connected to the line of said instrument, a step-up sec- 'ondary winding adjacent to saidprimary winding, a sparking terminal of a spark .gap directly connected tothe line of said instrument, a second sparking terminal of said spark gap directly connected to earth,

and, in series with said secondary winding, spark terminals of a spark gap lnte'rsecting 3.-In a" lightning arrester forelectric inswitch, ja=primary winding'of said switch connected to the line of said instrument, a

a sparking terminal of; a spark gap directly connected-to the line of said instrument, a second sparkingterminal' of said spark'gap directly connected toearth, and, in series with said secondary Winding, spark, terminals in ionizing proximity to said earthed spark gap; 7

4. 1m a lightning arrester for electrical inswitch, a primary winding struments, an electromagnetic earthing switch, a primary winding of said switch connected to the line of said instrument, a step-up secondary winding of said switch, a

sparking terminal of a spark gap directly connected to the line of said instrument, a

second sparking terminal of said spark gap directly connected to earth, and, in series with said secondary winding, spark terminals of a spark gap intersecting said earthed spark gap.

5. In a lightning arrester for electric instruments, an electro-magnetic earthing switch, a primary winding of said switch connected between the line of'said instrum'ent'and said instrument, a step-up secondaryiwinding of said switch, a sparking terminal of a spark gap directly connected to the llne of said instrument, a second sparking terminal of said'sparkgap directly connected to'earth, and, in series with said secondary winding-spark terminals in ionizing proximity tosaid earthedspark gap.

6. In a lightning arrester for electrical instruments, an electro-magnetic earthing of said switch connected between the line of said instrument vand said inst-ri'iment, a step-upsecondary winding of said sw-itch, a s'parln'ng terminal of a sparkgap "directly connected to the line ofsaid instrument, -'a second sparking terminal of said-gapdire'ctly -con-' nected to earth, and inseries with said secondarywinding,'-spark terminals of a spark gap intersecting said earthed spark In testimony whereofl'have' signed my name to this specification.

ARTHUR ELLIOT BEATTI-E.

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