US 2161249 A
Description (OCR text may contain errors)
June -6, i939. 2,161,249 AFB. DIBNER, NOW BY JUDICIAL CHANGE OF NAME B. DIBNER TERMINAL SCREW LUG Filed July 9, 1935 INVENTOR ATTORNEYS PnemedJu e-e, less I r j 2,161,249
; umrsn sTA'rss [PATENT OFFICE. annals mammal. scnaw we Abraham Bernard-Dibner, Peekskill, N. YJ, now
by judicial change of name Bern Dlbner, assignor to Burndy Engineering 00., Inc., New York, N. Y., acorporation of'New York Application July 3, 1935, Serial No. 30,429 9 claims. (01.173-269) This invention relates to terminal lugs for of my invention will be described in detail in the electric wires, cables and the like, and refers specification as it proceeds. particularly to the type in'which the end of a In the accompanying drawing forming part wire or cable is gripped in a screw operated hereof:
clamp. r i Fig. 1 is a side elevation of a terminal lug 5 The main object of my invention is to provide made according to the invention and embodying -a simple and eflicient terminal lug of the solderthe main principles thereof, an end of a cable less type which is time saving in use and very beingshown in position in the lug. easy to apply. a Fig. 2 is a top plan view of the same terminal Another object is to provide a terminal lus lug.
' of the characterindicated-which is very easy Fig. 3 is a section of a modification of the and economical to manui'acturejand therefore terminal lug. readily-placed upon the market. f Fig. 4-is another view of the device of Fig. 1 It is a very important object to have ateras seen from the right, the end of a large' solid minal lug of this character provided with a cable being shown in position and in section. 15 clamping screw or bolt which is capable of ex- Fig, 5 is a similar view as in Fig. 4, exceptthat ertlng considerable clamping pressure upon' the' the overlapping top portion is attached together end of an electric wire or cable, even of the as by welding or soldering and wherein the end multiple strand type, so that the end of the wire of a multiple strand cable of relatively smaller m or cable is securely held and the lug thereby fixed size is shown than that in Fig. 4 and .generally upon the same. corresponding with the cable end of Figs. 1 and 2. A further object is to provide such a terminal Fig. 6 is a plan view of a blank of sheet metal lug'with a protective pressure bar which is autofrom which the main body of either of the lugs matically retained in assemblage with the lug of the preceding views may be made. when once placed in position therein-and serves Fig, 7 is a section similar to Fig. 3, illustratf' to protect the end of the wire or cable from muing. modification of the terminal lug as well as tilation by the clamp n screw 0f t e 8- of the pressure bar and set screw. It is also ,an, object to produce 9, lug of this Fig. 8 is a top plan view of the pressure bar the whi h is pted foruse with'a whole range used in conjunction with the set screw or bolt of sizes; of wires or cables, without requiring a] of Fig. 3. diiferent size of lug for each size of wire or par- Fig. 9 is a side elevation of the same pressure ticular thought or precaution but merely relegatbar. ing the matter of cable size -to be fitted to a "Throughout the views the same reference nusimple question of adjustment. merals indicate the same or like parts. Hereto- It is eve an je e e to have -1118 which, fore the great majority of cable lugs were inby virtue of its structural form automatically stalled on the ends of wires and cables by soldercenters the end of a wire in a position wherein ing th same on said wires and cables, necesthe c p Pressure applied e n i qua y sarlly involving the use of cumbersome and nuexerted in a balanced manner was to avoid inmerous tools, as well as hazardous equipment, jury to the wire during the application of the not to mention that often considerable time lug thereto. I would also be consumed in making such soldered 40 Another additional object is to so construct a installation. Naturally the necessity has been te min l ls f this p h w n h lampfelt for a more convenient type of terminal lug ing screw or bolt is screwed down upon a wire installation and as a result certaincable lugs end, its pressure tends to increase the friction have appeared upon'the market which avoid between the threads in the lug proper-and those the use of solder but they usually introduce new of the screw in order to cause, the screw to be problems and are also not simple in construc- .very firmly gripped in the lug so as to remain tion and also sacrifice some desirable feature securely in any attained position of adjustment. which'was actually present in the old type of It may be mentioned '8 n of the objects of soldered lug installation such as direct and rigid this invention that the lug proper embodying the connections and security thereof. main features thereof. may be made from In orderto avoid all the'disadvantages and instamped blanks of sheet metal bent into final conveniences invoived'in the operation of solderform and properly threaded toreceive the clamp in'g terminal lug installations according to the ing bolt or screw. old methods and also the use and even construc- It Further objects and the several advantages tion of the solderless types and particularly with 5 2 the foregoing objects in view the present invention is designed, and primarily consists of a one piece or unitary terminal lug body which may be attached directly to a panel board and to which the end of a cable or wire may be directly secured by means which will presently be described in detail.
Hence, in the practice of my invention a terminal lug body generally indicated at l, oi. metal such as copper or a suitable alloy, has a fiat lug portion 2 having an aperture 9 for a screw or bolt by which to secure the same to a connection on a switchboard or panel, etc., a tubular body portion 3 which is V shaped at the bottom as shown at 4 and has the two upper ends 5 and 6 overlapping each other. Through the overlapping members 5 and 5 a threaded hole extends into which a set screw or bolt 1 is fitted so that turning of the screw will cause the lower end thereof to approach or recede from the lower v shaped bottom 4 of the tubular portion 3 of said lug. If the end l2 of a cable i3 is thrust into the tubular portion of the lug and the screw 7 turned by fitting a screwdriver into its upper slot l I the screw will descend upon the cable end. and clamp the same between said screw and said V shaped bottom 6 in a vise like grip. As will presv ently be described, another means may be used to secure the overlapping ends 5 and 6 together.
' follow the screw whether However, in order to prevent the lower end of the screw from grating or grinding directly upon the wire or the cable, it is preferred to intro duce a pressure bar, one form of which is shown at I as shown in Figs. 8 and 9, so that said pressure bar is interposed between the end of the screw and the bare end of the cable. The
pressure bar in this form is bent doubleso'that the lower portion 22 has the upper bifurcated portions l9-l9 overlying the same with a slot IB between the bifurcations enlarged at it to fit the neck it of the set'screw. When the set screw 1 has been screwed part of the way into the lug and the pressure bar placed with the bifurcations l9-i9 straddling the neck it of the screw 1, it is but necessary to force the pressure bar home and the bifurcations will ride past the neck of the screw and finally seat in the enlarged portion 20, after which the pressure bar will be retained by flange or fiat head it upon said set screw, with the result that the pressure bar will the latter is screwed while the pressure bar the screw upwardly or downwardly, in turn will prevent loss Or removal of from the terminal lug.
An alternative device with integrally connecting overlapping ends, as shown in Fig.- 3, con-= sists in drifting metal downwardly as at a from the upper member 6 through member and then forming the screw thread in said drifted metal 8, the latter metal extending even past the lower surface of overlapped member 5' so that the screw thread is longer than if it merely passed through the two thicknesses of the overlapping members A double gain is thus attained,
- namely, that the length or the screw thread is increased and both overlapped members are as rigidly united. as-though riveted together. The
parts 3', 4', 5', 8 and 9' correspond to parts 3, 4, '5, 6 and 9, respectively of the other views.
'. It is nevertheless possible to omit drifting of the metal from one of the overlapped-members through the other and instead leaving the overlapping members free with the screw passing simply through the threaded thicknesses of each,
upon the screw shown er diameter is similarly gripped, the screw and pressure bar in this case being necessarily in lower positions. However, it is sometimes desirable to provide a clearance in the pressure bar for the head or flange I5 upon the lower end of set 'screw I and in order to afford such clearance,
an aperture 2| as shown in Fig. 8 is punched in the bottom portion 22 of the pressure bar so that even this clearance serves as an additional retaining means for the pressure bar upon the set screw, because the head or flange in Fig. 3, will tend to seat or spring into place in said aperture when assembling the pressure bar upon the screw. Naturally the thickness of the lower portiorrZZ of the pressure bar is at least equal to the thickness of flange l5 of the screw and the latter may even be less than the gauge of said lower portion 22. Manifestly, when a cable or wire is placed in position in the tubular portion 3 of the terminal lug and the pressure bar lowered upon the same by means of the set screw, the V shapedbottom will positively center the end of the cable exactly below said set screw so that all side strainsand unequal pressures with resulting injury to the cable are avoided, but the pressure exerted will nevertheless theoretically tend to resiliently open the -V shaped bottom t and spread the sides of the tubular portion 3 and simultaneously tend to pull .apart overlapping members 5 a and 6 of thedevice illustrated in Figs. 4 and '1,
so as to exert a shearing strain upon the set screw. This will,'of course, not shear the screw but will instead cause the threaded portions of members 5 and 6 to almost lock upon' the screw by a very' great resulting friction so that the screw is held fast without any danger of unscrewing or releasing the pressure bar from the cable. This very great resulting friction is caused by the substantially rigid body, which is but slightly deflected even when the mechanical means used to apply pressure to the conductor is tightened, in the modification where the overlapping portions of sheet metal are not interlocked.
- The blank from which the body of the connector of Figs. 3 and 41s made is shown in Fig. 6. The lug 2 is integrally formed with the bottom section 4, the side walls, and the overlapping ends 5 and 6. The bottom t is shaped to form av V and the sides and overlapping ends form the tubular body 3.
When forming the body portion for the device shown in Fig. 1, a hole shown incircular broken lines in member 6 of Fig. 6 is punched in the ends 5 and 6, which holes are subsequently tappedv for the screw 1.
When theblank is used for the modification shown in Fig. 3, a hole shown in circular broken lines in member 8, of Fig. 6, is punched in end 6 only and a larger hole, shown in circular broken lines in member! is punched so that the metal of the smaller sized hole may be drifted downward, as shown in Fig. 3 to lock the overlapping edges together and provide a longer length of metal, as indicated at 8, which is subsequently threaded for the screw 1, as previously explained.
It is obviously quite possible to grip more than one cable or wire in the lug because two or three the pressure bar is the V shaped flat lug portion 23 corresponds to the previously 1 or even more ends oi cables, wires or similar conductors can be connected to the lug simultanemay conceivably avoid ously, as this sometimes necessity for other connections.
A modification oi the pressure barprimarily is shown in Fig. 7, wherein aihorizontal strip portion" is disposed intermediate overlapping end .portions 28 and 28 oi the tubular portion 24 of the lug, 'while the bent downwardly in arcuate form beneath the set screw 3| and is intended to be constructed of resilient material so that the arcuate portion III will follow. the screw upwardly when the latter is unscrewed in an upward direction and will, of course, be pushed down by the screw into any downwardly projected position when the screw is screwed down toward bottom 26 of the samelug.' The described lug portion 2, whilethe V shaped bottom 26 is serrated or provided with teeth as in- .Qdicated at so as to more firmly grip .an end the lug. vOi course, the serrations of a cable when the latter is to besecured in may ,be the main that'the position due to the fact passes through portion 21 01' omitted if desired as they do not form feature 01' the invention. It is evident pressure bar remains in that set screw 3i the same, although in this form of the mg the so I I other'aperture for compressing 'a cable longi set'screw is 'mushroomed at its lower end 42 to prevent it from being removed from the lug by unscrewing the same. The-mushroomed lower end "thus serves as ameans for retaining the set screw in assembled condition with the lug in this form, nevertheless a set screw 1 of the form shown in Fig. 3 can also be used with a clip or split washer (not shown) forced into position about the neck It in known manner so as to permanently retain the set screw in the lug it so. desired.
In connection with the set screw it is obvious that "any kind oflscrew already known may be used and instead of having a rounded upper end merely provided with a slot II for receiving the screw driver, the screw may be surmounted by a square or hexagonal head, the size of such head being of no great importanceand the shape thereof naturallyi'orming no actual part of the invention.
In view of the foregoing description and the accompanying figures of the drawing which have now been disclosed, it is obvious that further variations may be resorted to and parts may be used without others within the spirit and scope or the invention.
Having now fully described my invention, I
claim .a T-shaped blank of sheet metal, the side wings v bent into a tubular shaped body having a bottom and side walls, and overlapping apertured ends forming the top portion, the leg of the T forming a flat terminal place, and a clamping screw threadedly engaging at least one of the apertures in ends and passing through the tudinally into'the connector body.
2. An-electrical terminal for electric cables comprising-a substantially rigidbody made from a T-shaped blank 01' sheet metal, the side'wings l bent into a tubular shaped body having a tom and side walls, and overlapping, attac ed,
apertured ends-forming the top portion, the leg of the 'T forming a iiat'terminal plate, and a remaining portion 3| of a clamping screw threadedly engaging at least one of the apertures in the attached ends and passing through the other aperture for compressing a cable longitudinally into the connector body 3. electrical terminal for electric cables comprising a substantially rigid body made from a T-shaped blank of sheet metal, the side wings body, said interlock consisting of metal drifted from one overlapping end into the aperture of the other.
4. A terminal lug for electric wires, cables and the like, forming an inseparable assembled'unit and comprising in combinatiom-a U shaped member oi metal having a flat lug portion integrally connected to the bottom portion thereof in parallelism with the axis of said U shaped member and having the upper ends 01' the same bent over each other so as to mutually overlap, and an ad- Justable clamping screw extending through both 01 said overlapping upper ends ofsaid U shaped member toward the member with said lower portion formed into a V shaped bottom merging with said flat lug portion and the sides of said U shaped member terminating at their upper ends in a pair 01' bent mutually overlapping portions, and an adjustable clamping screw extending through both or said overlapping'portions of said U shaped member toward said V shaped bottom in order to cause said bottom to spread or open and said overlapping portions to tend to separate and exert a transverse shearing strain upon said screw when the latter is brought down under pressure upon the end of a cable within said U shaped member and thereby tend to automatically retain the screw by friction in any attained position upon said cable.
' 6. A terminal lug according to claim 4, wherein the lower end of the clamping screw is rotatably connected to a'removable pressure bar disposed and guided between the sides 0! the U shaped member and is movable upwardly and downwardly with the screw when the latter is rotated, one portion or said pressure bar being bifurcated and said bifurcated portion straddling said bottom of the latter in order to cause said bottom to spread or open and saidstraddling said clamping screw above said flange.
9. A terminal lug according to claim 5. wherein the clamping screw has a flange upon the lower end thereof and a removable pressure bar is mounted upon and retained by said flange and is disposed and guided between the sides of the U shaped member so as to be upwardly or downwardly movable between said sides upon rotation oi said screw one portion 01. said pressure bar being bifurcated and said biiurcated'portion straddling said clamping screw above said flange.
ABRAHAM BERNARD DIBNER.