US2188135A

US2188135A - Connector with washer cap

Info

Publication number: US2188135A
Application number: US148491A
Authority: US
Inventors: Lee Marvin; Rogoff Julian
Original assignee: Burndy Engineering Co Inc
Current assignee: FCI USA LLC
Priority date: 1937-06-16
Filing date: 1937-06-16
Publication date: 1940-01-23
Anticipated expiration: 1957-01-23

Description

Jan. 23, 1940-. M. LEE ET AL 2,188,135

CONNECTOR WITH WASHER CAP Filed June 16, I937 INVENTORS MARVIN LEE & JULIAN RosoFF BY Patented Jan. 23, 1940 UNITED STATES 2,188,135 comc'ron wrrn WASHER car Marvin Lee, Rye, and Julian Rogoff, New York, N. Y., assignors to Burndy Engineering Co. Inc., a corporation of New York Application June 16, 193'], Serial No. 148,491

4 Claims. (Cl. 173-269) This invention relates to connectors and more particularly to connectors employing caps or pressure transmitting elements between nut and ca 1e.

6 In Patent No. 2,049,409 issued to Bern Dibner, a cap of this nature is disclosed. These caps are either cast or forged. When such a cap is clamped on soft drawn copper cable, it is necessary to provide some means of locking the joint .10 against loosening from vibration. This is usually done by using a lockwasher which is inserted between the nut and the 'cap.

This fourth element addedg to the cost, and.

further made it necessaryfoi the installer to take into consideration an additional piece to handle, which would be burdensome-in inconvenient locations; waste time, and increase the possibility of parts dropping.

Accordingly, a primary object of our inven- 1 tion consists in providing a cap that possesses all the features of a lockwasher in a single unitary construction, thus'eliminating an extra ele-v ment.

We have found that when soft drawn cables are u clamped in these solderless electrical connectors,

they have a tendency to be gradually relieved of the clamping pressure for several reasons.

One reason is that the strands of the cable,

being clamped under high pressure, will gradually 80 distort andmesh intocloser relationship with a resultant smaller diameter.

Another cause is the expansion and contraction of the cable and connector because of tem- 2 perature changes. If there is any difference at Sliall in the thermal coeflicients of expansion-of the cable and the connector, a change in temperature will cause an uneven expansion or contraction. A cycle of expansion and contraction I may cause the cable to loosen. do A third reason is the creep of the cable, which, being preferably of copper possessing a high conductivity, is soft and does not have a yield point. The constant tension or pressure -will permanently deform the cable, loosening the 45 connection, and reducing its electrical emciency. Another object, therefore, is to provide a cap capable of maintaining a constant pressure on the cable to a degree unobtainable byan ordinary cap and lockwasher. 60 In addition, these caps or pressure transmitting elements had'broad pressure applying surfaces, so that the cable would not be deeply indented by point contacts with greati pressure concentrations.

All these features necessitated the use ofa solidly forged or cast connector possessmg considerable weight, increasing the shipping charges, and adding to the cost of the connector.

A further object, therefore, is to provide a cap, weighing a fraction of the average cap, yet possessing suiiicient strength to enable the use of high pressures to insure good electrical joint efilciency and containing sufliciently large pressure areas to avoid point contacts with the cable.

We attain these and other objects, and accom- 10 plish our results by providing a sheet metal combined pressure cap and washer, as will be readily apparent from a consideration of the following description and claims taken together with the accompanying drawing in which:

Fig. 1 is a side view of a connector provided with washer cap.

Fig. 2 is an end view of the same.

Fig. 3 is a top view.

Fig. 4 is a top view of the cap. 20

Fig. 5 is a side view of the same.

Fig. 6 is a front view.

Fig. '7 is a side view of our cap applied to another type of connector.

Fig. 8 is a sectional view through the line 8-8 of Fig. 4. v

Fig. 9 illustrates the cap with outwardlyv extending arms.

Referring more particularly to Fig 1, reference numeral l0 designates the complete connector in which a cable is provided with a terminal block l2.

' The connector is provided with main and auxiliary clamping members [8 and It, with troughs I 5 and I6 forming a socket in members l3 and M respectively. I

The cable ll passes through the eye ll, .of the eyebolt [8, which is'integral with the main socket member and rises normally thereof, terminating in the threaded bolt section IS. A nut 20 threadedly, engages the bolt IQ for applying pressure to the cable. 1 a.

I The auxiliary socket member II is in the form of a sheet metal cap'having an aperture 2| centrally located on the upper surface 22. 5

The sheet metal cap is preferably drawn into a rectangular cup shaped section with two

opposite arms

23 and 24 extending beyond the

sides

25 and 26 and inwardly-drawn or outwardl see Fig. 9) and formed into a trough it, previously described.

While the cap illustrated is rectangular in form, the particular shape is immaterial, the necessary' feature residing ina contact surface for the nut, and two normally extending trough u shaped arms for receiving the cylindrically shaped cable.

The trough shaped

arms

23 and 24 extend inwardly approximately to the sides of the eyebolt l8 and the extreme edges 21 and 2B are downwardly positioned so that they will first engage the cable before the surface of the trough comes in contact with the surface of the cable.

The entire cap H, is made of springy metal, the two

arms

23 and 24, resiliently giving under the applied pressure until there is a surface contact of trough and cable.

The spring effect of the cap may be increased or decreased by raising or lowering the two other side walls, the lowering of these walls reducing the length of the

sides

25 and 26 to' which the trough arms are attached. This will make the trough arms more rigid and tend to prevent their springing action. Thus when the other side walls have been removed, the

sections

25 and 26 remaining provide maximum resiliency to the arms.

The eyebolt l8 may be constructed free of the terminal block l2, and made into an auxiliary socket member, as shown in Fig. 7; the pressure block becomes the current carrying member and its design may be modified accordingly. The terminal block 29 shown in this figure is inserted between the cap and nut, the eyebolt 30, entering an aperture 3| in the extension 32 of the terminal block 29, and the nut tightened as before.

When identical connectors, one with the sheet metal cap and one with the solid forged cap are tightened with identical values of wrench torque,

there is an increase in the pull-out value of the.

sheet metal cap over the forged cap of between 20 to 50%. We attribute this increase in pullout value to the effect of the edges 2!- and 28 biting in the'cable before the pressure areas engage, holding the cable s'ecurely in place.

We have thus described our invention, but we desire it understood that it is not confined to the particular forms or uses shown and described,

the same being merely illustrative, and that the invention may be carried out in other ways without departing from, the spirit of ourinvention, such as the use of a washer cap employing our invention in a. connector joining two cables together, instead of the terminal shown and, therefore, we claim broadly the right to employ all equivalent instrumentalities coming within the-- What we claim and desire to secure by Letters Patent, is as follows:

1. A connector for electric cables comprising a plurality oi cable clamping members forming a socket for receiving a cable, one of which is made of sheet metal having a surface upon which the clamping pressure is applied, and integral therewith, a pair of sections extending transversely to clamping pressure is applied, side walls extending transversely to said surface and terminating in a pair of oppositely positioned resilient arms having cable clamping sections extending longitudinally of the cable receiving socket, and means for applying pressure to the surface of the sheet metal cable engaging member for clamping-the cable between the members.

3. A connector for electric cables comprising a plurality of cable clamping members forming a socket for receiving a cable, one of said cable clamping members having extending threaded means, the other of which is made of sheet metal having an apertured surface upon which the clamping pressure is applied, side walls extending transversely to said surface and terminating in a pair of oppositely positioned resilient arms having cable clamping sections extending longitudinally of the cable receiving socket, and a nut for engaging the threaded means projecting through the apertured sheet metal surface for applying pressure thereto and clamping the cable between the members.

4. A connector for electric cables comprising a plurality of cable clamping members forming asocket for receiving a cable, one of said cable clamping members having extending threaded means, the other of which is made of sheet metal having an apertured surface upon which the clamping pressure is applied, side walls extending transversely to said surface and terminating I clamping members, having a plurality of apertures, one for receiving the threaded means and the other for fixedly attaching said connector.

JULIAN ROGOFF.