US402810A

US402810A - Supporting and cross-connecting electric wires

Info

Publication number: US402810A
Authority: US
Publication date: 1889-05-07
Anticipated expiration: 1906-05-07

Description

(No Model.)

W. J. DENVER.

SUPPORTING AND CROSS CONNECTING ELECTRIC WIRES. No. 402,810. Patented May '7, 1889.,

Maw 2 MWQW, W 32 N PETERS. Phmwblhographer. Wnhmgtm, QC:

UNITED STATES PATENT OEEIcE.

lVILLIAM J. DENVER, OF BOSTON, MASSACHUSET SPECIFICATION forming part Of Letters Patent No. 402,810, dated May '7, 1889.

Application filed November 24, 1888. Serial N01 291,739. (No model.)

T0 aZZ whom it may concern.-

Be it known. that l, \VILLL-mi J. DENVER, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain Improvements in Supporting and Cross-Connecting Electric lVires, of which the following is a specification.

In the construction of telephone-lines it has been found necessary, in order to avoid the effects of induction from other circuits, to cross, transpose, or change the relative position of the several wires. It has been found that such lines as are to be operated as metallic circuits, whilefree from induction due to causes external to the system, are especially liable to sulfer from the effects of mutual or reciprocal induction, whereby messages in course of transmission over any one circuit manifest themselves also on other and parallel circuits, interfering with and disturbing the business of the said other circuits, and also depriving; the system of the secrecy in communication which is essential. It is therefore particularly necessary that the two wires of the several metallic circuits should be crossed with one another or change places with each other on their supports at frequent intervals. This expedient has been adopted and is now in extensive use on long telephone lines. It has nothing in common with a method of obtaining inductive neutrality, which has also been used to some extent, and which consists in causing the several wires traversing the same route to circulate spirally round each other in a species of open twist; but, on the contrary, its use obviates the many disadvantages of the spiral or twist style of construction. 7

In the practical application of the necessary cross-connections referred to they have been made wherever introduced by providing the poles at which they are to be made with double cross-arms, one oneach side of the pole, and each being provided with pins and insulators for each line, the pins on one arm being usually opposite the pins on the other. The lines approaching from either direction have been then terminated and fastened to the insulator on that one of the cross-arms which is nearest, in such a way, for example, that lines running eastwardly from a given pole terminate and are fastened. to the eastern cross-arm, while that part of the line which com cs from the west terminates at and is fastened to the opposite \vestern crossarm insulators. These, then, are virtually parts of the same line, but separated by the space between the pins of the two cross-arms. The wire coming from one direction is now connected by means of a suitably-long piece of insulated wire with a wire leading to the opposite direction, the two, however, not being in line with each, but crossed at the junction, so that of the two wires of a circuit No.1 east will thus be connected to No. 2 west and No. 2 east with No' 1 west. This mode of making the required cross-connections is defective both electrically and mechanically, because in the first place it introduces a great many joints or splices, which are often, either by accident or design, left unsoldered, and because, in the second place, there is a constant tendency in the entire construction to pull itself apart, for, as will be at once seen, each stretch of wire, being terminated at and upon the insulator on the cross-arm on the same side of the pole as that from which it approaches, pulls with a strong strain upon the said cross-arm, and as the two crossarms of a pair are each in this way steadily pulled in opposite directions and away from the pole to which they are attached, it follows that an element of mechanical weakness is always present.

My invention consists in certain arrangements of the several pins, insulators, and wires at crossing-points, whereby the beforedescribed defects are avoided; and it also consists in providing supports for any two wires, which supports shall respectively be on diiierent levels, whereby the said two wires may be crossed without danger of contact with each at the crossing-point, each of the higher supports being next in line with one of the lower ones, so that at any crossing-point both higher and lower supports are placed diagonally with the member of the same level.

It further consists specifically in combining the said high and low supports with the several line-wires, so that a perfect and noninterfering transposition of any two wires can be made, while the introduction of splices is avoided.

In the drawings which illustrate this speci fication, Figure l'is a perspective view of a portion of a pole with a double cross-arm, illustrating two of my forms of cross-connection. Fig. 2 is a similar view showing the plan adopted on the left side of Fig. 1. Fig. 3 is a similar View showing two metallic circuits arranged on the plan adopted on the right side of Fig. 1. Fig. 4 represents a plan whereby a double cross-arm may be dispensed with. Figs. 5 and 6 represent perspective and plan views of methods of cross-connection practiced before my invention, in which the actual crossing of the wires takes place in the middle of the span. Fig. A represents the old and defective mode of cross-connection, which I seek to improve.

Considering, first, the case depicted in Fig. 2, we see a portion of a pole, 1, at which a pair of line-wires, or any number of pairs of line-wires, are to be transposed. The figure shows four wires, or two pairs. The wire w is to chan e laces with w and the wire 10 is to change places with w. A cross-arm, 2, is fastened to the one side of the pole, and a second one, 3,to the other side of the pole,

opposite to the first. In line with each of the wires I affix two pins carrying insulators, one 011 each cross-arm, so that there is pair of insulators at the cross-connection pole for each line. It will be observed that the several wires are not connected with the two i11- sulators in line with one another, but that wire to, coming from a given direction, is supported first on one insulator, 5, of crossarm 2, but from thence is diverted to insulator 6 on cross-aim 3, pursuing its route now on the second line instead of the first. So, also, wire 10 which, coming from the same direction on the second line, is first fastened to the insulator 7 on cross-arm 2, passes 0 liquely to insulator 4: on cross-arm 3, and continues its course on the first line; and the same is true with. respect to

wires

10 and 10, mounted upon and fastened to insulators l0 and 11 and 8 and 0, respectively.

It is evident that a contact would be made at the point where the two wires of any pair cross each other unless some means he adopted to prevent. I provide to this end supports which have provision for the attachment of the wires on different levels or horizontal planes, and I attach one of the wires to the supports which are diagonal to each other on one of the said levels, and cause the other to pass obliquely between and to be affixed to the remaining pair of supports, which of course are also diagonal to one another, on the lower level, whereby a considerable air-space is made to exist between the two wires at the point where they cross each other, and as the oblique stretch of wire between the two diagonally-placed supports is so short and as the said wire is fastenedat both supports it will be seen that it is impossible that sufficient sag should take place to allow the wires to come into contact, and inasmuch as the space is so short between the supports on the'two crossarms it is certain that temperature expansions and contractions maybe disregarded. In the special case illustrated by this figure this difference of level is eifected by placing two wire-supporting and tie-wire grooves, A, on each insulator at the required levels, and by fastening one of the Wires to the higher groove of one diagonal pair and the other wire to the lower groove of the other diagonal pair of insulators.

In Fig. 3 the same designating letters and numerals of reference are used, and the same mode of effecting the transposition of the two wires of any pair is employed, embodying also the same principle of providing supports by means of which the two wires shall cross one another 011 different horizontal planes; but the idea is carried out specifically in another way-namely, by using ordinary single-groove insulators and by making the pins which support them of different heights, as shown. This plan can be adopted where doublegroove insulators are not accessible.

Fig. 1 shows on one side the pole the specific arrangement of Fig. 2, and on the other the arrangement of Fig. 3.

Fig.A needs no special description. Similar wires are shown; but each wire, as herein described, is absolutely terminated at the insulator which at first approaches from either direction, and the two sections of any particular line-circuit, w 10 &c., are united by short links of covered wire, W, which, of course, require a splice at each end and to each of the two sections which it unites. I have pointed out the deficiencies of this plan.

In Figs. 4 and 5 I show plans of cross-connection in which double cross-arms are not essential.

In Fi 4 the cross-arm 2 is fastened in the usual manner upon the pole. It is provided with the same double-grooved insulators which are shown in Fig. 2, mounted on pins of usual. and equal height. Wire 10, approaching insulator 28, is attached to the lower groove thereof, and, passing half round, is extended longitudinally along the cross-arm to the groove on the same level of insulator 29, to which it is then also attached, and then, passing half round the said insulator, continues its course in the line approached by the second wire, 10 The said second wire on its part approaches first insulator 29, and is in the same way attached thereto, but to the higher groove thereof, and, passing to the higher groove, also, of insulator 28, continues its course in the line of the approaching wire 20'.

In Figs. 5 and 6 an older mode of crossconnection is shown, in which one of each pair of insulators is. placed on the upper side and the other on the lower side of the cross-arm. I make no claim to this plan, it being old, and in two respects, in some degree at least, objectionable, in that the actual crossings are made at the middle of the span, and the lines are therefore likely to make contact with-each other, while at the cross-arm the lower support has been found in practice to receive more moisture in wet weather and to tend to undue and unequal leakage.

It will be seen that by my invention the transposition of the wires is accomplished without in any way weakening them, and without introducing splices or joints, and at the same time without any risk of contact between the wires at the point where they cross one another. Not only so, but by the adopt-ion of these plans the transpositions can be made while the wire is originally being strung, not requiring workmen of any par ticularly high degree of expertness.

I clain1 1. In a system of electric pole lines, the combination of two line-wires stretched parallel to each other, and crossed so as to ex change places at suitable intervals, with means at the said crossing-places for effecting the said crossing without breaking the continuity of the wire, said means comprising a double cross-arm, insulating-supports for each wire and to which each wire is fastened 011 both cross-arms, the said supports being constructed, as shown, so that those in the same line of continuity are at different levels, while those diagonal to one another are at the same level, the said line-wires being each respect ively attached to the two supports which are diagonal. to each other, substantially as and for the purposes described.

2. The combination, substantially as hereinbefore described, in a system of electric line-wires mounted on poles, of the two wires of a metallic circuit, w and 10 the cross-arms 2 and 3 opposite one another to a pole, 1, a support consisting of a pin and insulator on each of the said cross-arms for each of the said wires, two of the said supports having long and the remaining two having short pins, and being so disposed that one of the long pins and one of the short pins shall be fixed to each cross-arm and that in each case a long pin on one arm shall be opposite a short pin on the other, but diagonal to the pin of like length with itself, and the two wires being attached one to the two short-pin supports and the other to the two long-pin supports, and being thereby crossed on different horizontal planes and caused to exchange places without impairing their continuity and without danger of contact, for the purposes specified.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 22d day of November, 1888.

\\ ILLIAM J. DENVER.

Witnesses:

GEo. WILLIS PIERCE, FRANK O. LooKwooD.