US2484144A - Electrical connector - Google Patents

Description

Oct. ll, 1949., c. A. BADEAU l ELECTRICAL CONNECTOR Filed Sept. 17, 1947 F162 INVENTOR. CARROLL AEAUEAU www l wf TIUR'NEY lllllllllllll Patented Oct. 11, 1949 U Nel TED STATES;

ATENT QFFICE ELECTRICAL CONNECTOR Application September 17, 1947, Serial'No. 774,565

4 Claims.

and constructed as to increase the positiveness and durability ot its pressure connection when used to join electrical conductors in line for splicing together two wires as well as when tap connecting them in an vangular or cross relation for leading a branch wire to lighting and other electrical` equipment.

A further purpose is to produce a simple twopiece connector,V as an improvement upon the old U-body type, which loops around a `conductor or conductors runder screw-pressure and which` embodies means to eliminate all shearing Atendency of the clamping screw in `order to prevent damage to conductors when anchored under clamping pressure within the, body of the connector and also to eliminate fatigue in a wiring installation by which to maintain the initial maximum pressure on a wiring connection.

The-accompanying drawings illustrate the simplicity of construction of this electrical connector, as comparedY to know-n U-body types, and demonstrate its utility in ltwo principal applications of electrical wiring installations, as follows:

The first three views of the drawngs show the connector wthout the conductors, while the last four view-s show two applications of the connector to conductors in the make-up of .wiring instalflations. i

Fig. l fis a side view with diagram lines applied thereto for reference -in the description to follow.

Fig. 2 is an end view of the electrical connector.

Fig. 3 is a transverse section taken lon .the line 3 3 through the body of the connector looking into the end of its clamping screw.

Figs. 4 and 5 .are comparison views showing the connector joining or splicing two conductors in line or in parallel.

Fig. 4 shows a longitudinal section before ap.- plying clamping pressure; and Fig. 5 `is a similar view after tightening the clamping screw under pressure.

Fig. Gris a side view, and Fig. 7 is ,a bottom view of the connector with two conductors disposed at an angle, as for example, lapped crosswise o f each other and under clamping pressure in the connector body.

Referring further to the drawings -ior aV description of an example of an embodiment of the invention, it will be seen that a connector of modied U-body type is here characterizedA and. improved by i-nwardly converging arms having angular seats which engage the conductors and secure them together (either in alignment or in cross relation) in a new ymanner with resulting advantages in wiring installations (splicing and tapping) calling for this type of connector.

The connector body may be die-formed from sheet copper and includes a headl portion I0 with two shoulders Il and two integral arm portions l2 made of flat stock. The head' I0 is hole extruded and screw-tapped to receive an operating or clamping screw lwith its inner end extending inward and midway ofl the arms l2; The screw I3l is adapted. to be tightened into clamping pressure -by screwing it inward against the near or uppermost .conductor of the two wires W as shown in the drawings which illustrate insulatedrwires of the solid type. The connector is also well adapted for use on wires and cables of the stranded type.

Of importance is the fact that the two arms l2 converge inward from their shoulders li and toward each other in an angular relation which disposes their outer free ends rather close together and in `a spaced relation much less than that of said shoulders. In fact, the outer free ends of the two arms .l2 are here shown as being spaced a distance less. than the diameter of the clamping screw l2. rIhus` the two arms carried on the head iii! are not parallel (as in `known types of connectors) but .converge toward` `the axis of the screw. This is an important improvement in structure over the art in respect to prior U- shaped connectors', asiurther study ,of my invention will reveal.

Next, it is pointed outr that each arm l2 is provided with an `elongated aperture' which deiines two spaced arcuate wire-receiving seats having two inner edges ylil `disposed comparatively close to the axis of the screw The wire apertures .lli have a .width adapted t0 the 10241- ticular size of the wire -W for which the connectar is manufactured, that is, the width oi the wire-opening seats id is slightly greater than the diameter of the bare or ole-insulated portion of the wire. lThe -lengfth of the two apertures ill extends parallel with the axis of the screw i3 and is slightly greater than Athe total diameter of the ,two wires Wv introduced into -the connector. Also7 lit is seen that the two `apertures l are axially .aligned .perpendicular to the axis of the screw t3'. l

A flange I15 is extruded outwardly .from leach `edges of said flanges are pointed to at I6. The

two arm anges I5, therefore, provide two large- `area wire-contact seats I4, IB at the outer free ends of the arms I2. These large-area seats insure an effective electrical contact and mechanical grip by the connector on the lower or outermost wire W, while the screw I3 establishes a good grip on the innermost wire W.

The illustration in Fig. l aids in explaining the invention. Parallel reference lines P are tangent to the outer margins of the shoulders I I and are `extended beyond the length of the converged arms l2 in order to demonstrate that the shoulder portions II are the widest part of the connector. In other words, the two wire-seat edges I6 are seen to be not wider apart than the two shoulders Il; in fact they are, preferably, well within the reference lines P and hence are spaced apart a distance less than that of the shoulders Il.

Now it is seen that the outer linear edges of the two flanges I5 may be substantially parallel if desired, while the arms I2 converge non-parallel toward each other. It is also observed that the thin or narrow portions of the flanges I5 do not necessarily follow around the edge contours of the wire apertures adjacent the head IU. However, the wide flange portions I5 do rim and follow around the edge contours of the arcuate aperture seats I 4, I6 at the free ends of the two arms I2 to provide large-area bearing-contact seats for the outermost wire W placed therein.

Another feature of the invention resides in the angular relation of the two spaced arcuate wire seats I4, I6 to each other and to the axis of the wire W placed therein. It is seen that the two closely spaced inner edges I4 are located further from the axis of the wire W than the outer edges I 6 and that such arrangement tilts the largearea seats I 4,l I6 at an angle to the wire axis. This novel feature causes the wire W initially to rest only upon the two outer edges I6 (Fig. 4) before the screw I3 is tightened for producing pressure engagement Vfirst at the biting edges I6 and then along the entire area of the wire seats I4, I6 (Fig. 5).

The foregoing novel features of construction eliminate the tendency of the screw I3-when tightened under maximum pressure for compressing the wires W in the connectorto bend, shear or break the wire strands and also prevent the arms I2 from spreading. In old connectors of the U-body type, the arms thereof are parallel and do not have a spacing at their outer free ends'which is less than the screw diameter.

Consequently, in the old type connector, the great pressure of the clamping screw not only may bend and apply a shearing tendency against the outermost wire W in its seat but also may cause the old type parallel arms to spread. In other words, the inner edges of the old type wire seats squeeze and cut into the electrical conductor, thus damaging it, and in addition to the latter fault the old type parallel arms sometimes undergo a creeping-apart action which loosens the grip of the connector on its wires.

The use and operation of mynew modified U- body type of screw-pressure connector herein, with its new form of angular wire seats I4, I 6 in pairs, possesses an advantage in the relation of the diameter of the screw I3 to the spacing of the outer free ends of the converging body arms I2 which loop around and embrace one or both conductor wires W. This new relation to the distance bridged by the wire or wires W, across the short open space between the two angular wirereceiving seats I4, I6 formed in the free ends of the arms, provides new results, as will be appreciated by further study of my new connector. As previously recited, the space or distance between the outer free ends of the arm pair I2 is not greater than-and preferably is less thanthe diameter of the body of the screw I3.

Accordingly, the two spaced inner edges I4 of the wire seats at the free ends of the arms I2 are in alignment with the body of the screw I3 and not in alignment with the circumference thereof as in old connectorsso that the clamping pressure exerted by the screw is not applied critically at the edges I4 of the wire seats but inwardly thereof (in a new manner) on and along and also within the area I4, l5 of said seats. This new structural feature prevents outward distortion ofthe shortened span of the wire or wires W which reach across the minimum open space from one arm I2 to the other arm I2 and, consequently, prevents the two arm seats from cutting into the electrical conductor under the pressure of the clamping screw I3. Such feature also stays the two arms I2 from creeping apart under the clamping pressure of the screw.

When the first wire W is introduced through the apertured arms I2 it rests initially upon the two sharp arcuate edges I6 of the wire-receiving seats (Fig. 4). As clamping pressure is applied by the screw I3, the two seat edges I5 begin to bite through the oxideon the wire and gain a Virgin-metal contact to produce an unusually effective electrical connection. The two seat edges I3 establish a bite on the bare wires which permanently wedges the two arms I2 against spreading. As pressure of the screw I3 increases (Fig. 5), the two inner edges I4 are drawn toward the wire W until surface-area engagement is established between the wire and the entire portion of the arcuate seats I4, I6.

'Ihus in mode of action, my new connector, firstly, bites into the wire W at the two points I6 (Fig. 4) for making positive electrical connection and, secondly, draws and wraps against the wire at the two points or edges I4 (Fig. 5) for positive mechanical connection. It is believed that my new fitting herein is the irst of its typeV in this particular class of connectors to achieve this dual-function connection with a single clamping screw acting in conjunction with a simple looped-type body and leading to the new results herein recited.

The foregoing new mode of pressure connec-v tion-in its freedom from distortion of the wires W and shearing tendency thereagainst-also results in greater positiveness and duration, hence permanency ofV pressure connection. In other words, since distortion of the wires W does not occur, there is no tendencyfor my new connector to loosen gradually due to compression fatigue of the wires after a workman has tightened the screw I3 and left the job. In previous types of U-body parallel arm connectors, the pressure of the screw in its old position eventually fatigues` the conductors, andthe latter gradually recede from the tightened screw, with the result that prior type connectors do not maintain their initial maximum pressure on the conductors over a long period of time.

Now it is understood more clearly that the converging arms I2, which loop around and embrace the wire or wires W and progressively grip at the four spaced edges I4 and I6, do not have a tendency to spread apart under clamping pressure by a gradual creeping action along the bottom or outermost conductor W. In prior connectors having old-type parallel arms, the latter sometimes undergo a gradual creeping action away from the axis of the screw. Such old mode of operation leads eventually to loss of pressure by the connector on its wiring installation.

My new connector, with its converging arms I2, has its two spaced wire-receiving seat inner edges Ill in line with the body of the screw I3, and maximum clamping pressure is constant and permanent in its applied force axially of the screw and perpendicularly to the wires W. Hence, pressure of the connector does not exert a spreading force on its arms, and no loosening tendency develops from that source after a workman has installed the connector under iinal screw pressure. The initial clamping pressure remains constant and the installed connector is permanent and positive.

Accordingly, the converging arms I2, aided by the angular seat I4, I 6 pair, constitute simple features in a new combination which provide against fatigue distortion of the conductors W, as well as providing against fatigue spreading by creeping tendency of the arms II. Both of these conditions pose problems which are inherent in prior art connectors of the old parallel looped-arm U-body type, and either condition operates singly or together to work a gradual loosening-up of the old connectors after they have remained in service for a period sufciently long to fatigue the conductors and/or fatigue the connector itself. My new connector is so designed and constructed as to overcome both of these faults, as will be apparent from the description herein and also as demonstrated by test and use of this connector.

The disclosure herein explains the principles of the invention and the best mode contemplated in applying such principles, so as to distinguish the invention from others; and there is particularly pointed out and distinctly claimed the part, improvement or combination, which constitutes the invention or discovery, as understood by a comparison thereof with the prior art.

This invention is presented to iill the need for a new and useful electrical connector. Since various modications in construction, mode of operation, use and method, may and often do occur to others, after acquaintance with a particular invention, it is to be understood that this disclosure is exemplary of the principles and of equivalent constructions without being limited to the present showing of the invention.

What is claimed is:

1. An electrical connector comprising a body including a head integrally formed with two spaced arms, each arm being provided at its outer free end with an aperture, the two apertures being axially aligned and thereby forming two spaced seats which are adapted to receive and support electrical conductors disposed one upon and in engagement with the other, a clamping screw operatively mounted in the head and being adapted to app-ly pressure against and perpendicular to the conductors midway of the two axially-aligned spaced seats, and the outer free ends of the arms converging toward the longitudinal axis of the screw, with the two seats spaced apart a distance less than the diameter of the clamping screw.

2. An electrical connector as described in claim 1, and wherein the arms and head join on each side of the clamping screw to form spaced shoulders, and also including a flange formed along the edge of each aperture in each arm thus enlarging the areas of the seats supporting the electrical conductor, such connector being characterized by the fact that the outer edges of the iianges are spaced apart a distance less than the distance between the spaced shoulders.

3. An electrical connector as described in claim 1, each of the two spaced seats of which is disposed at an angle to the axis of the two aligned apertures, thereby providing a contact edge on each seat which initially engages the conductor, and the operation of the clamping screw of which rst acts to lbite the contact edges into the conductor and thereafter to draw the angular Seats into final parallel pressure engagement with said conductor.

4. An electrical connector as described in claim 3, but further characterized in that the outer contact edge of each seat is closer to the axis of the two aligned apertures than the inner contact edge of each seat, whereby the initial biting engagement of said two outer contact edges act to increase the resistance against spreading of the seats away from each other.

CARROLL A. BADEAU.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,276,011 Baxter Aug. 20, 1918 2,045,847 Fotsch June 30, 1936 2,339,354 Rubel Jan. 18, 1944 2,430,159 Chenier Nov. 4, 1947

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