US3075038A

US3075038A - Connector assembly

Info

Publication number: US3075038A
Application number: US636096A
Authority: US
Inventors: William G Schinske
Original assignee: Ideal Industries Inc
Current assignee: Ideal Industries Inc
Priority date: 1957-01-24
Filing date: 1957-01-24
Publication date: 1963-01-22
Anticipated expiration: 1980-01-22

Description

Jan. 22, 1963 Filed Jan. 2:1. 195'? w. e. SCHINSKE 3,075,038

CONNECTOR ASSEMBLY 2 Sheets-Sheet 1 Jan. 22, 1963 w. G. SCHINSKE 3,

CONNECTOR ASSEMBLY Fil ed Jan. 24, 1957 2 Sheets-Sheet 2 In 06 71 for 1017mm 6 .flckz'zzfire United States This invention is in the field of connectors and is a new and improved insulating cap with a connecting structure, constructed and arranged to be turned down or screwed over the stripped ends of a plurality of electric wires, for example, two or more, either stranded and/ or solid, of the same or different sizes, or otherwise.

A primary object of the invention is a new and improved electrical connector of the screw-on type.

Another object is a connector of the above type with expanding ears or lobes which provide leverage when the cap is turned down over the wires but which can easily be cut off, for example, by a pair of electricians pliers or the like.

Another object is a cap connector of the above type, preferably made of nylon, polyethylene, or other suitable thermoplastics, which functions both as a wrench and as an insulating shell or cover.

Another object is an insulating cap connector with a coil spring insert arranged so that the resiliency of the cap follows the variations in size and dimensions of the coil spring.

Another object is a connector with a cap and coil spring insert constructed so the spring cannot be vibrated out of the cap.

Another object is a connector arranged to simultaneously connect and insulate wires carrying either high or low voltages.

Another object is a connector which will not work off of the wires, due to vibration or otherwise, after it has been screwed on.

Another object is a connector constructed so that the user can tell when it is fully mounted.

Other objects will appear from time to time in the.

ensuing specification and drawings in which:

FIGURE 1 is a plan View of my connector; FIGURE 2 is an end view of FIGURE 1;

FIGURE 3 is a section along line 33 of FIGURE 2; FIGURE 4 is a section along line 44 of FIGURE 3;"

FIGURE 5 is a plan view of the spring or insert without the cap or shell;

FIGURE 6 is a section similar to FIGURE 3 with the smallest combination of wires; and

FIGURE 7 is similar to FIGURE 6 with the largest combination of Wires.

In FIGURE 3 the connector is shown with a cap or insulation or cover which has been indicated generally at 10 and may include a generally cylindrical body or shell 12 closed at one end by an end wall 14 or the like, which is preferably integral with the cap and general- 1y open at the other end at 16, providing what I shall refer to as a generally open central bore 18. The bore of the cap or shell houses or encloses a generally tapered coil wire spring or the like 20. For purposes of designation this spring has a large end 22 and a small end 24. The large end 22 is disposed generally at the open end of the bore at 16 and terminates at 23 while the small end extends back into the bore toward the end Wall 14.

I' may provide an enlarged or thickened portion 26 in the cap or shell generally at the open end which may be formed with a threaded portion or relief section 28.

on the inner surface, providing at least one full turn and preferably several. The threads may be molded directly into the thickened portion 26 and the large end atent ice coil at the large end so that a force fit or compressive interlock is provided. I prefer to make the cap or shell out of nylon, or polyethylene, or any other suitable thermoplastic material which is tough but somewhat resilient and at the same time a good dielectric and suitable for high temperature use. Also, the material should be sufficiently resilient to follow any variations in spring size. The material might have what is commonly referred to as plastic memory. Thus the thickened portion 26 yields somewhat under the outward expansive bias of the coil but at the same time exerts an inward circumferential tightening or compressive tendency firmly locking the coil in the shell.

The inner surface of the bore may remain somewhat cylindrical but the intermediate or middle turns of the coil decrease in diameter or taper as at 29 so that a clearance or spacing is provided at 30 throughout the majority or a substantial portion of the length of the proximately the same as the large end 22 of the coil butit may vary somewhat. This expanded turn serves as a guide or pilot for the small end of the coil. It should be understood that this turn does not necessarily form an interference or compressive or force fit with the cap but may merely engage it. But it might form an interference or compressive fit. In any event, the important point is that this expanded turn 32 pilots the small end and centers it relative to the axial bore of the cap. Also the spacing 36 is not totally necessary, and the spring could have the same pitch throughout its length.

The end 34 of the wire may be tended slightly or pulled away from the normal turns of the coil as at 36 and an abutment 38 is provided in the shell, preferably but not necessarily integral with the side walls and end wall, to provide a shoulder or anchor for the end of. This abutment or shoulder may be of any. suitable formation but I prefer that it oppose the end of Y the coil.

engage the abutment regardless of its particular size, shape, or disposition.

The open end 16 of the cap is provided with an enlarged, preferably integral, skirt 40 which is preferably cylindrical and well rounded at 42 where it joins the shell or cap to function as a guide or funnel for the entering stripped ends of the wires. The skirt 40 may be considered a part of the cap or shell. The cap and skirt are preferably both formed of nylon or the likef The skirt should be extended sufiiciently axially to shield the wires against arcing to a ground by providing a sufficiently extended dielectric path so that the cap can be used for either high or low voltage installations.

Outstanding from the skirt I may provide one or more cars 44 as in the FIGURE 3 form which are preferably integral and also of nylon or the like. I have only shown two such ears but more could be used. The point is that these ears provide leverage to enable an operator to manually turn the cap down over the wires. I At the same time the cap could be arranged for auto- The end 34 of the coil might be blunt, turned in or back, or otherwise suitably shaped to 1 The end wall 14 forming the closedend of the bore is offset at 48 in all forms to provide a socketor cavity 50 behind the abutment 38 so that the stripped ends of the wires may extend somewhat beyond the abutment. The material of the cap and particularly the material of the end wall 14 may be transparent or relatively translucent so that the operator can tell when the stripped ends of the wires are fully seated by observing. them through the end wall 14. I might also make the coil insert a distinctly different color from the color'of the wires to be connected so that the operator could easily tell the difference. For example, if the wires tobe connected are copper and .have a golden color, the coil spring mighthave a zinc or silver color, and vice versa. If the wires.

to be connected are aluminum, the coil'spring insert might be copper plated.

. In addition, the socket 50 allows the -wire combination to move fully into thebore of the connector. If. the. wires of the combination are misaligned ornot bunched or collected properly so that oneextends outbeyond the;

others, nevertheless, the socket 50.provides sutlicient penetration so that the joint or connection will be tight, and all wires will be fully engaged, the. short as .well as the long. I t a 1 In FIGURE 1, I might also provide a gauge mark 51 or the like which the operator could use to accurately. determine the lengthy of insulation to be stripped from the wires, but this is optional. t The use, operation and function of my invention are as follows; i

,, The cap, or shell is intended both as a cover or insulation/and as a wrench, I prefer that the cap, skirt andears, all beformed integrally or molded as one. piece but they might beotherwise for certain requirements, 'Once the unit is screwed down on the wires and firmlyaseated, the ears are of sucha size, shape and dimension that they can be cut off. For example, I find it practical. to dimen; sion, the cars so that the cutting blade on a. conventional.- pair of electricianspliers can ,be'used to snip themedto,

provide more. room in a conduit box, if such ears fare' se 2 h tion does not necessarily have to be thickened. Also the compressionfit might beprovided, at the rear turn 32, Yand several such enlarged or expanded, turns might be pro-; vided at 3 2. In any event from the front. toward the.

closed end or bottom of the cap, the turns ,of thejfcoil taper and separate: from and move out of contact with the cap. The expanded turn or turns atboth ends centerfthe. coil and. prevents it from flexing. or skewing the cavity thereby breaking the interlock. The abutment at the closed end'ofthe cap serves as an anchor for theeoil.

,{Ihe spring expands when it is turneddown loverfthe wires, particularlyv the taperedportio na29, but ltprefer.

that remain as rigid as possible to make a, low resistance electricjoint. v I

,Asshown in FIGURE '6, the smallest combination of wires willexpand thetapered or conical. portion 29 somewhat, particularly atits small end 24 just before the enlarged turn 32. The largest combination of wires shown in FIGURE 7 will expand practically or substantially the entire length of the tapered or conical portion 29. In fact, the spring will become, substantially cylindrical and may engage, the wall of the housing or shell 18 practically throughout its entirelength. When the spring expands laterally, it contracts in length and'l'preferthat FIGURE 3.form, thethickened portion26 inthe cylindrical capprovides a firm outer seat or. interlock for. the-large end of the coil and the internal screws or. threads compress the last few turns at the-open end. This.,por-..

the compression fit or interlock, whether it be at the front end 22 or the rear end 32, is such that the contraction in length will not disconnect the interlock. In FIG- URE 6 the lesser expansion caused by the smallest com binations has drawn the end 23 backa portion of a turn but in FIGURE 7 the largest combination causes an expansion that may draw the end 23 back as much as a full turn. In either case the large end of the spring decreases somewhat in size when it is screwed down on the wires, but the so-called plastic memory of the cap causes it to follow the spring down. Regardless of the combination of wires used, the wires will extend the same distance into the cap. The large loop or expanded turn 32 may not interlock with the wires but rather may serve merely as a centering means. I have stated that the cap is preferably made" of nylon but it could be otherwise, so long as the material is a suitable insulation, has suitable rigidity to prevent the spring from coming out, and suitable compressive force to provide the interlock with a part of the coil. It is important that the material of the cap compressively hold the spring so that during ship" ment when connectors are normally jostled and vibrated somewhat violently, the coils will not work out of the caps. In this case the resiliency of the cap holds the spring in the cap and it will not come loose, either during shipment or after the connector is in use. Additionally; the connection or joint will not change with the 'heat caused by the flow of electric current. The plastic memory or flexure of the cap will allow it to follow thespring, even with high currents.

While I have shown and described a preferred form and suggested several modifications of my invention, it should be understood that numerous additional modifications, substitutions, alterations and changes may be made without departing from the inventions fundamental theme. For example, I have shown the wire of the coil as having a circular cross section and it could be square or any other suitable shape. The dimensions of the parts are not important except whenindicated. Ihave men-- tioned nylon, but the material of the cap might be otherwise. The abutment orshoulder-64 might be a separate insert but I prefer that it be integral. With these and other modifications in mind, I wish that the invention be unrestricted except as by the appended claims.

1. In an article of manufacture, a connector for joining the stripped ends of electric wires or the like, including a, capwith a generally central bore open at one end and closed by} an endv wall at the other end, the material of the cap being a "stifily flexible plastic having the characteristic of plastic memory, a generallytapered wire coil in the 'bore, thelarger end of the coil being adjacent the open end of the cap, a portion of the coil being held in resilient compression by a corresponding portion of the cap bore in tension, the coil. portion in compression having a normal outside diameter in a free state substantiaL' 1y "greater than the normal inside diameter of the corresponding boieportion in a free state, the coil being ta,- pered toward the closed end wall of the cap and being out of contact with the cap bore for a substantial dis-.

tance so that' when the connector is screwed down on the wires, the coil portion in compression, will be reduced in diameter, and, at the same time, the corresponding b'ore" portion'will contract and willmaintain firmcontac't with the coil portion, and an abutment in the cap engaging thecoil to'prevent thecoilfromturning in the cap when the connector is'screwed down on the wires.

'2." The structure of claim l'in which 'the'smaller end of the coilhas an expanded turn which contacts the surface of'the bore to pilot and center the small end of the coil causing the end of the wire spring to engage the abutment.

3; The structure of claim 1 in which formed integrally withthe cap.

'4. The"sti-ucture' of'claim "1 further characterized by the abutment is and including an integral enlarged skirt on the cap at the open end, and a plurality of integral outstanding ears on the skirt constructed and arranged to be manually grasped when the cap and coil are being turned down over the stripped ends of wires.

5. The structure of claim 1 further characterized by and including a plurality of integral outstanding ears on the cap constructed and arranged to 'be manually grasped and actuated to rotate the cap when it is being turned down over the stripped ends of the wires.

6. The structure of claim 1 in which the material of the cap is nylon, and further including a threaded section in the bore of the cap at the open end in mesh and resilient compression with the turns at the large end of the coil.

7. In an article of manufacture, a connector for joining the stripped ends of electric wires or the like, including a generally cylindrical cap with a generally central bore open at one end and closed by an end wall at the other, the material of the cap being of a plastic having the property of plastic memory, a wire coil in the bore tapered throughout the majority of its length and out of contact with the wall of the bore, the larger end of the coil being adjacent the open end of the cap and held in resilient compression due to a substantial interference fit with the bore so that the large end of the coil is reduced somewhat and is in compression and the corresponding portion of the bore is expanded somewhat and is in tension due to the larger end of the coil having a normal outside diameter in a free state substantially greater than the normal inside diameter of the bore in a free state so that when the connector is screwed down on the wires, the larger end of the coil in compression will be reduced in diameter and, at the same time, the portion of the bore in tension will contract and will maintain firm contact with the larger end of the coil, and means in the cap engaging the coil to prevent the coil from turning in the cap when the connector is screwed down on the wires.

8. The structure of claim 7 further characterized by and including an integral abutment in the shell engaging the end of the wire spring at the small end of the coil to prevent the coil from turning when the shell and coil are turned down over the stripped ends of a plurality of wires.

9. The structure of claim 8 further characterized in that the shell has an integral enlarged skirt at its open end, and further including a plurality of integral outstanding ears on the skirt constructed and arranged to be manually grasped to rotate the cap when it is being turned over the stripped ends of the wires, and a threaded section in the bore of the shell at the open end adjacent the skirt in mesh with the spring at the large end of the coil, the material of the shell being nylon and providing a compressive force fit between the large end of the coil and the shell.

10. In an article of manufacture, a connector for joining the stripped ends of two or more electric wires, including an insulating cap with a generally central bore open at one end and closed by an end wall at the other, the cap being of a stiffiy flexible plastic material having the general plastic memory characteristic of nylon, a generally tapered wire coil in the bore, the larger end of the coil being adjacent the open end of the cap and held in resilient compression, due to a substantial interference fit, by a corresponding portion of the cap bore in tension, the coil portion in compression having a normal outside diameter in a free state substantially greater than the normal inside diameter of the corresponding bore portion in a free state, the coil being tapered toward the closed end wall of the cap and being out of contact with the cap bore for a substantial distance, and means in the cap engaging the coil to prevent the coil from turning in the cap when the connector is turned down on the wires.

References Cited in the file of this patent UNITED STATES PATENTS 704,869 Fischer et al July 15, 1902 1,678,752 Van Gelderen July 31, 1928 2,036,561 Barrett Apr. 7, 1936 2,110,458 Applegate Mar. 8, 1938 2,186,963 Meyer Jan. 16, 1940 2,729,695 Pierce Jan. 3, 1956 2,748,186 Lee May 29, 1956 2,772,323 Smith Nov. 27, 1956 2,792,560 Bollmeier May 14, 1957 FOREIGN PATENTS 654,131 France Nov. 20, 1928 381,501 Great Britain Oct. 6, 1932 678,994 Great Britain Sept. 10, 1952

Claims

1. IN AN ARTICLE OF MANUFACTURE, A CONNECTOR FOR JOINING THE STRIPPED ENDS OF ELECTRIC WIRES OR THE LIKE, INCLUDING A CAP WITH A GENERALLY CENTRAL BORE OPEN AT ONE END AND CLOSED BY AN END WALL AT THE OTHER END, THE MATERIAL OF THE CAP BEING A STIFFLY FLEXIBLE PLASTIC HAVING THE CHARACTERISTIC OF PLASTIC MEMORY, A GENERALLY TAPERED WIRE COIL IN THE BORE, THE LARGER END OF THE COIL BEING ADJACENT THE OPEN END OF THE CAP, A PORTION OF THE COIL BEING HELD IN RESILIENT COMPRESSION BY A CORRESPONDING PORTION OF THE CAP BORE IN TENSION, THE COIL PORTION IN COMPRESSION HAVING A NORMAL OUTSIDE DIAMETER IN A FREE STATE SUBSTANTIALLY GREATER THAN THE NORMAL INSIDE DIAMETER OF THE CORRESPONDING BORE PORTION IN A FREE STATE, THE COIL BEING TAPERED TOWARD THE CLOSED END WALL OF THE CAP AND BEING OUT OF CONTACT WITH THE CAP BORE FOR A SUBSTANTIAL DISTANCE SO THAT WHEN THE CONNECTOR IS SCREWED DOWN ON THE WIRES, THE COIL PORTION IN COMPRESSION WILL BE REDUCED IN DIAMETER, AND, AT THE SAME TIME, THE CORRESPONDING BORE PORTION WILL CONTRACT AND WILL MAINTAIN FIRM CONTACT WITH THE COIL PORTION, AND AN ABUTMENT IN THE CAP ENGAGING THE COIL TO PREVENT THE COIL FROM TURNING IN THE CAP WHEN THE CONNECTOR IS SCREWED DOWN ON THE WIRES.