US2938069A - Compression type electrical connectors - Google Patents

Description

May 24, 1960 J. A. TOEDTMAN ETAL 2,938,069

COMPRESSION TYPE ELECTRICAL CONNECTORS Filed March 7, 1957 \37 INVENTORS 3 Jmu A. TOJDTMAN,\ Y WILLIAM WILTON 35 ATTORNEYS.

United States Patent 2,938,069 COMPRESSION TYPE ELECTRICAL CONNECTORS John A. Toedtman, Richmond Heights, and William E.

Wilton, Webster Groves, Mo., assignors, to Jasper Blackburn Corporation, St. Louis, Mo., a corporation of Missouri Filed Mar. 7, 1957, Ser. No. 644,594 4 Claims. (Cl. 174-94) This invention relates to improvements in compression type electrical connectors.

The objects of the invention are: To provide 'an improved wire connector of extremely simple and economical construction; to facilitate the operation of connecting a tap-off or branch wire to a through main line; to improve such connections from the standpoints of me chanical strength and conductivity; to reduce galvanic corrosion at the connection, especially where the wires are formed of dissimilar metals, and to provide an improved device of the character described which can be used for connecting wires in a wide range of ditferent sizes.

The invention resides in the novel shape and construction of the connector as set forth in the appended claims.

In the drawing:

Fig. 1 is an end elevational view of our improved connector;

Fig. 2 is a side view showing said connector in assembly with but prior to being compressed on to a pair of conductors;

Fig. 3 is a side view, similar to Fig. 2, showing the assembly thereof after the application of the compression tool;

Fig. 4 is a sectional view taken at line 4-4 of Fig. 3;

Fig. 5 is a side view of a modified form of the connector as installed on a pair of conductors, and

Fig. 6 is an end elevational view of the connector of Fig. 5.

Our improved connector comprises an elongated unitary body of ductile metal, preferably aluminum, formed to provide therein a pair of longitudinal, parallel wire passages. Its transverse or sectional shape is uniform throughout its length so that the devices may be conveniently and economically made from extruded bar stock.

As best appears in Fig. l, the connector has the general shape of numeral 6, in cross section. It may be considered as having a tubular lower portion 5 which defines and completely encircles the lower wire passage 6, and a generally hookor channel-shaped upper portion 7 integrally joined to portion 5. Upper portion 7 defines the upper wire passage 8 and a side entrance opening 9 leading to said upper passage Opening 9 extends the full length of the connector and enables a conductor such as A to be introduced laterally into passage 8, or enables the connector to be hooked on to a span of a through conductor. It will be observed that the lateral entrance opening 9 extends upwardly and inwardly at an angle to the vertical plane through the axis of the wire passages 6 and 8 so that the connector will remain suspended when hooked on to a horizontal span of wire.

Now describing the connector in greater detail, the tubular lower portion 5 includes the arcuate wall 10, underlying passage 6, which wall is of maximum thickness ice at the sides of said passage and decreases to minimum thickness at the lower center. Longitudinal grooves, or recesses 11 and 12 are provided in the outer surface at the sides of lower portion 5, these grooves being desirably located with their lower surfaces 13 situated approximately in the horizontal plane through the axis of passage 6. Accordingly, the grooves 11 and 12 are located above the said plane but within the horizontal projection of passageway 6. Grooves 11 and 12 reduce the thickness of the body or wall portion at the sides of passage 6, defining the relatively short and narrow, deformable neck portions 14 and 15 at the opposite sides of passage 6. The described provisions allow the parts to yield and be formed about the wire and reduce the pressure requirements to accomplish this result, and, importantly, when compression is applied, function to induce an inward collapse of the said neck portion. Such is desirable to eliminate gaps and to produce a strong, full surface contact between the connector and the wire.

The body portion indicated at 17 of the connector above the groove 12, at the base of the hook-shaped upper portion 7, is relatively massive in order to resist deformation in that zone. It will be observed that the wire passages 6 and 8 are separated by the web or partition 18, preventing direct contact between the engaged portions of the conductors.

The upper wire passage 8 has an inner cylindrical surface or conductor seat 19 that extends circumferentially through an arc of approximately 240 degrees, the side entrance opening 9 extending through an arc of approximately degrees. When compressive pressures are applied to the connector the upper portion 7 is caused to bend about the conductor A in passage 8 to reduce the size of the passage and entrance opening, and, in instances of a relatively small conductor, closing said entrance opening entirely. Upper portion 7 is reduced in thickness at 20, immediately above the point of its merger with the lower portion 10, by the provision of a shallow cavity or recess 21 in the outer side surface adjacent the base of upper portion 7. As will be understood, tool pressures exerted inwardly on the top and bottom surfaces of the connector cause the hook-shaped flange to bend, principally about its reduced portion 20, into close embracing engagement with the conductor A. The diameter of passage 8 in its original state is made sufliciently larger than the largest conductor intended to be accommodated therein so that proper bending of portion 7 and the flow of its metal under tool pressure will cause its end surface 22 to approach the surface 23.

In Figs. 5 and 6 there is illustrated a modified form of the connector, which form has special application and usefulness for connecting wires of different metals such as copper and aluminum. This form of the device is desirably made of aluminum and has particular advantage in eliminating or effectively reducing damage to the aluminum conductor caused by galvanic action. It may be used with great advantage for making a T or tap-oft connection between wires of aluminum and copper, such as those designated C and D, in coastal or other areas where the effect of corrosion is especially manifest.

The modified connector of Figs. 5 and 6 differs from the form previously dsecribed in that the hookor channel-shaped upper portion 30, including the part 31 (Fig. 6) of the partition that separates the passages 32 and 33, is extended longitudinally for an appreciable distance beyond the ends 34 of the tubular lower portion 35. The said end prolongations of the upper portion are designated 36.

As will be understood, when a junction of wires of dissimilar metal become moist or wet, especially by an electrolyte such as salt spray, galvanic currents are generated which tend to flow through the wet surfaces and to erode the wire of less noble metal. Such currents and their damaging effects on the wires are minimized with the use of the connector shown in Figs. 5 and 6, first by reason of the substantially increased length of the wet surface flow path between the wires, and secondly, by affording a cover or shield over the emerging ends of the lower wire that sheds moisture therefrom.

An important advantage of both described connectors is their ease of use and application in making a tap connection of a lead-off wire with the through span of an overhead line. Thus, an end of a tap wire B, for example, may be inserted through lower passage 6 and a strand or so bent to retain the wire against accidental withdrawal from the passage during subsequent operations. The connector with tap wire B attached is hooked on to the line conductor A which will then support the assembly. Both hands of the operator will then be free to manipulate the applicator tool. Such tool, of which there are several available to the trade, applies compressive forces to the upper and lower surfaces of the con nector, producing the indentations or grooves which are indicated at 24, Fig. 3 and 40, Fig. 5. The upper portion of the connector is caused to bend and closely embrace the wire A, as has been described, and the lower portion 5 is caused to bend about the wire B in passage 6 and conform closely thereto. Instead of bulging outwardly and producing pockets or gaps at the sides of wire B, the reduced neck portions 14 and 15 collapse and fill the voids between the wire and wire passage in the described manner. Intimate, full perimeter contact be tween the conductors and connector results in a connection having great mechanical strength and low electrical resistance. 7

Whereas our invention has been illustrated and described with reference to two preferred forms of connector devices, it will be understood that various changes and modifications may be made without departing from the spirit and intendment of the invention or from the scope of the claims hereunto appended.

It is desired to claim:

1. An electrical connector adapted to connect dissimilar wires comprising an elongated body having integral upper and lower portions, longitudinal wire passages in said upper and lower portions extending from end to end of said body, an integral partition separating said passages, said upper portion and partition projecting ax ially beyond the ends of said lower portion, at both ends of the body, whereby to provide a cover over both the emerging ends of the wire extending through the lower wire passage and to increase the wet surface flow path between the wires, the body having longitudinal grooves at opposite sides of the lower wire passage and within the horizontal projection of said lower wire passage, said grooves being below said partition,

2. An electrical connector adapted to connect dissimilar wires comprising an elongated unitary body including a substantially tubular circumferentially closed lower portion forming a lower wire passage therethrough having end openings at both ends of said body, and a substantially hook-shaped upper portion forming an upper wire passage having end openings at both ends of said body and a lateral entrance opening extending the full length thereof, an integral partition separating the passages, said upper portion and the partition between said passages projecting longitudinally beyond the ends of said lower portion, at both ends of said body, whereby to provide a cover over both the emerging ends of the wire extending through the lower wire passage and to increase the wet surface flow path between the wires.

3. An electrical connector adapted to connect dissimilar wires comprising an elongated unitary metal body including substantially tubular upper and lower portions providing upper and lower wire passages extending end to end of said body, the upper tubular portion extending axially beyond the ends of the lower tubular portion at both ends of said body and having a longitudinal entrance slot at one side, extending the full length thereof, the extended tubular portion adapted to provide a cover over both the emerging ends of the wire extending through the lower wire passage and to increase the wet surface path flow between the wires. 1

4. An electrical connector adapted to connect a pair of dissimilar wires comprising a metal body having integral upper and lower portions providing upper and lower wire passages extending end to end through said body, an integral partition separating said passages, the partition between the upper and lower wire passages extending beyond the ends of the lower wire passage at both ends of the body so as to provide a cover over the emerging ends of the wire extending through the lower wire passage and to increase the wet surface flow path between the wires.

References Cited in the file of this patent UNITED STATES PATENTS 2,229,758 Metcalf Jan. 28, 194l 2,296,443 Kleinfelder Sept. 22, 1942 2,327,683 Warner et al. Aug. 24, 1943 2,707,775 Hoffman et al. May 3, 1955 2,748,366 Bergan May 29, 1956 2,789,277 Schumacher Apr. 16, 1957 2,884,478 Becker et al. Apr. 28, 1959 FOREIGN PATENTS 602,963 Great Britain June 7, 1948 512,689 Canada May 10, 1955 730,579 Great Britain -a May 25, 1955

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