US1948701A - Lightning arrester - Google Patents

Description

Feb. 27, 1934. E. A. EVERETT LIGHTNING ARRESTER Filed Feb. 18. 1929 Patented Feb. 27, 1934 UNITED STATES PATENT OFFICE 9 Claims.

This invention relates to lightning arresters and is a combination of the so-called vacuum tube arrester and the spark-gap arrester. The objects of the invention are to improve the mounting and assembly of arresters of this type whereby they may be assembled and disassembled without changing the characteristic of the arrester. Another object of the invention is to insure that the vital parts will bear a predetermined relation to each other when assembled by making them self adjusting; another object of the invention is to provide a mounting for the vacuum tube which is self centering and which protects the tube by a cushioned support. Other objects of the invention will appear from the following specification and the accompanying drawing, in which, Fig. l is a plan view of the arrester complete, Fig. 2 is a side elevation, partly sectioned, corresponding to Fig. 1, Fig. 3 is atransverse elevation on the line 33 of Fig. 2, Fig. 4 is a detail, partly sectioned showing the tube mounting, Fig. 5 is a plan view of the discharge block holder before assembly, Fig. 6 is an elevation of the discharge block assembly with the holder sectioned on its longitudinal centre; and Fig. '7 is a longitudinal plan view of the spark gap portion of the arrester.

This invention is a continuation of my copending application, Serial No. 328,270, filed December 24., 1928. It comprises a porcelain base upon which is detachably mounted a vacuum tube with discharge electrodes. These tubes are generally referred to as vacuum tubes although the preferred tube for this purpose is filled with an inert gas and the discharge is obtained by the ionization of this gas. In combination with this tube and in multiple circuit therewith is a sparkgap arrester. with the parts loosely mounted and held together by spring pressure. Inoperation the vacuum tube will discharge lightning of comparatively low voltage, while the spark-gap arrester will discharge the higher voltages and larger current. It should be understood that each portion of the arrester functions by itself and the features of the invention applying to each portion may be used by itself without the other portion. If the vacuum tube should become damaged, the spark gap arrester would continue to protect the circuit and the resistance block which is connected in multiple circuit with the vacuum tube arrester would discharge surges of comparatively low voltage.

In the drawing, 11 is the porcelain base on which the binding posts 12 and 13 are mounted by which connections are made to the circuit to be protected. The vacuum tube and its mounting is indicated by 14 and is supported by the clips 15 which are secured to the base by the binding posts 12 and 13. The base is provided with a recess at 17 in which a choke coil may be placed connected to the binding posts 12 and 13. This is not shown in the drawing.

The vacuum tube comprises the sealed glass receptacle 22 having conductors sealed through its ends which connect with the clips 15 when 65 in the mounting and which terminate in discharge plates 34a and 34b as shown. These are rectangular plates, preferably placed at right angles to each other so that their closest point is on the longitudinal centre of the tube and the sparking distance between them gradually tapers from this point. An advantage in construction arises from this arrangement for if these plates were parallel to each other they would have to be located with precision to prevent them getting 7 out of parallelism.

In my previous application the glass tube was loosely mounted between the ends 21--21 which are spaced by the bars 24 and 26. In this case the tube was supported by the connectingwires and was subject to displacement and the wires were liable to be broken and the tube rendered useless. In this invention the tube is provided with soft rubber caps 61 which snugly fit the end of the tube as indicated in section at 62, Fig. 4.

and fit the recess in the ends 21. These rubber caps centre the tube in the ends as these ends are driven onto the spacing bars 24 and 26 and the tube is held rigid on the rubber seating when as? sembled without injury. It is apparent that by 90 42 connecting to binding post 12 and is located in 95 the recess a in the base. This comprises a holder secured by lugs 66 to the spring 41 by bending these lugs around the spring as shown. In this holder a block of resistant material 46 is placed which fits transversely in the recess a. Resting ,9 on its edge on this block and free to slide thereon is the mica spacer secured to the spring 42 by a jaw construction. One side of this jaw terminates in discharge teeth at 4''! the inner members of the jaw being plain as indicated in Fig. 3 and $9 the sides of holder 45 are provided with discharge teeth as indicated in Figs. 3 and 5 which discharge to the jaw of conductor 42 holding the spacer 50.

The discharge takes place through resistant block 46 and ver its surface.

It will be noted that the resistant block 46 is clamped between 41 and 42 by spring pressure and if these springs are not parallel the spacer 50 would engage the block at one corner and form a gap at the opposite corner. In consequence the air gap would be increased and eiiiciency and accuracy of the arrester would be greatly impaired. In order to prevent this condition a transverse ridge is formed in holder 45 at 65 and block 46 centers upon this ridge as indicated in Fig. 6 so that it is free to swing with the spacer 50 and a uniform distance is assured between the discharge teeth at 47 and the surface of 46 which is the controlling discharge gap.

It will be noted that as the blocks 46, or the parts of the spark gap arrester are replaced the conditions of a uniform spark gap are maintained.

The drawing shows a preferred form of my invention, but the claims cover a full range of equivalents.

Having thus described my invention, I claim:

1. In an arrester as described, the combination, a base, a pair of terminals on said base, a flat spring extending from each of said terminals, said springs being in alignment and overlapping each other, a resistant block mounted on one of said springs, spark gap discharge points connected with one of said springs adjacent the sides of said block, a plate of insulation secured to the opposing spring engaging said block by its edge and being free to slide upon said block in line with said springs and spark gap discharge points connected with the other spring adjacent one of the sides of said plate.

2. In an arrester as described, the combination of a base, a pair of opposed and aligned overlapping conducting members supported by said base, one of said members supporting a block of resistant material and having spark gap discharge points connected therewith, the opposing member secured to a plate of insulation by spring pressure and having discharge points in sparking relation with the first mentioned discharge points, said plate of insulation being mounted so that its edge engages said block and being arranged to slide freely on said block in line with said conducting members.

3. In an arrester as described, the combination, a pair of overlapping conducting members placed in alignment, one of said members supporting a block of resistant material, the other member having discharge points and having a flat mica spacer secured thereto, said spacer held in engagement on its edge with said block by spring pressure and being free to slide on said block in line with said conducting members.

4. In a spark-gap arrester as described, the combination, a pair of conducting members placed in alignment biased to approach each other and separated by a block of resistant material and a flat spacer of insulation secured to one of said members resting on its edge on said block and being free to slide transversely on said block in line with said conducting members and at least one of said conducting members provided with discharge points.

5. In a spark-gap arrester as described, the combination, a pair of conducting members placed in alignment and arranged with adjacent ends overlapping each other and having a channel associated with the end of one of said members, a block of resistant material placed in said channel and a plate of insulation secured to the opposite member and separating said members and at least one of said members having a spring bias to apply pressure to said resistant material and said plate being mounted so that its edge engages said block and is free to slide upon said resistant material in a direction transverse to said channel.

6. In a spark gap arrester, the combination, a comparatively rigid, flat conducting member, a channel shaped holder having spark gap discharge points associated therewith secured to said member, a transverse ridge in said channel, a rectangular block of resistant material located in said channel and being free to rock upon said ridge and a second fiat conducting member having spark gap discharge points associated therewith located in sparking relation with the opposite face of said block to the face engaging said ridge whereby a uniform sparking relation is maintained between said second member and said block.

I. In an arrester, the combination of a base, a pair of opposed overlapping conducting members supported by said base, means forming a ridge on one of said members, a resistant block mounted to rock on said ridge, a spacer of insulation mounted to slide on said block and connected with the other member and spark gap discharge points arranged in sparking relation connected with each of said members.

8. In a spark gap arrester, the combination, a pair of conducting spring members having between them spark gap discharge points, a resistant block, means electrically connected with one of said members for holding said block in position and providing a rocking motion for said block and means for clamping said block be tween said members by the spring action of said EDWARD A. EVERETT.

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