USRE18773E

USRE18773E - Asbighob

Info

Publication number: USRE18773E
Authority: US
Publication date: 1933-03-21

Description

45 the accom anying drawing,

Reisaued Mar. 21, 193:

UNITED STATES PATENT oer-Ice GREG] none, 13., m was, ABBIGNOB 1'0 m not &

nrn'soo. 01mm, A (DBIPORL'l-IOII ormwnmssr cum: cosine-rim Original Io. 1,881,056, dated December 1, ESL-Serial Io. 886.088, "fled January 80, 1928. Application for reissue Med December 83, 1988.. Serial In. 8,491.

- This invention relates to outlet box fittings such as connecters for use with electrical outlet box assemblies and the like, and more particularly relates to cable connecters for securing cable to boxes used in connection with house and building electrical wiring ]obs and installations.

An important object .of this invention is to produce a combination cable connecter and m ground wire connecter in one and the same device.

Another object is to'produoe a novel cable connecter simple in structure .and easy touse and which will positively anchor a cable to anoutlet box, as well as simultaneously anchor itself to the box by actuation of a single operating means; and a further object is to aproduce a connecter provided with groun wire connecting means by which a special ground wire contained in the cable may be attached to the connecter and hence to the outlet box to establish a positive electrical ground connection to render safe the wirin system.

A iirther object of the invention is to produce improvements in cable clamping means forming a part of the connecter, the

I clamping means being actuated by an operating means to fix the cable in the box; and in one form of the invention, the reaction force produced b the operating means simultaneously anc ors the connecter in the box knock-out. Ina modified form of the invention, the operat' means merely functions to actuate the ca le clamp since there is provided a separate and independent anchorage means to fix the connecter in the box. In both forms I provide a ground wire connecting screw to electricallyconnect with a cable ground wire. I 7 Having the foregoing objects and others in view, the invention relates to improvements in construction and use as shown in the examples of the invention portrayed in wherein: V Figure 7 shows a side e evation, F e 2 a longitudinal section, and Figure 3 an'mside end elevation of the cable connecter.

4 shows, respectively, a side and Q and elevation of a novel cable clamp loosely erted on the cable in the direction of the arsection of the box assembly and the tilted back position of the lower end of the clamp and illustrates how its front end or edge di into the cable to more firmly grip the ca le in event a strain or pull is exrow tending to 'erk the cable from or loosen it in the box. ground wire GW contained in the cable C is shown electrically connected with the cable connecter.

Figure 5 shows a box assembly view in longitudinal section with the box, the cable connecter and the cable in finall anchored position, and with the ground wire GW attached to the connecter. blFigure 6 is a plan view of the box assemca le connecter and cable anchored in place; and. Figure 7 is an outside end elevation thereof.

Figures 8 and 9 show a modified form of the invention, Figure 8 being a lon 'tudinal igure 9. be' an outside end elevation thereof. This modified form of combination ground wire and cable connecter diifers from the main form only in the box anchorage means to fix' the connecter in the box, since in this modified form I employ an ordinary lock nut'to anchor the connecter in the box, whereas in the first form: of the invention I employ a with the combination ground wire and single operating means such as a clamp screw to perform all functions of anchoring the connecter in the box, securing the cable in It)l(1 e box, and connecting a ground wire to the x.- In house wiring installations, a box B is anchored to the building in the usual way and a cable C containing electrical wiring W is introduced through the box knock-out or hole H formed in the box. Electrical wire counections are made with the current feed wires W in the box for supplying current to tmfifi'xtures, electrical appliances and the ike an the invention relates to improved I B so as to render the wiring system safe. A

single screw is made to perform the several purposes of anchoring the connecter in a box,

attaching the cable to the box, and securing a ground wire to the box. My improved connecter is especially adapted for use with cable C, whether fiber or metal armored, which includes a special third wire GW adapted for grounding purposes.

The connecter consists of a casting or frame part made in any suitable sha such as a connecter member 12 which 1S here shown as a sleeve and on which the movable parts are mounted. The sleeve 12 may as- 'sume various forms of .construction which are apparent from an inspection of the two examples of the invention- One type of connecter member is shownat 12 in Figures 1 through 7, while another type of connecter member is shown at 30 in Figures 8 and 9. The connecter member may be made with a bushing 13 which acts as a stop against which rests the inner end of the cable C as shown in Figure 6. The other end of the connecter member is cut away at 14 thereby leaving an overhanging extending portion which projects beyond the edge 14 to produce a connecter member having a short and long portion. The cut away end' or face 14 of the member affords the flatabutment end or edge 14 which rests against the box 'wall when the connecter is installed. In this instance the connecter end portion 14 rests against the inside box wall surface.

- The casting 12 includes a box hole edge seat 16 raised on the member 12 and which may to advantage be formed on a radius substantially equal to'the radius of the box hole H so as to fit thereinto. This arcuate box hole edge seat 16 is eccentric to the axis of the mounted in the box hole.

The connecter sleeve -12 also includes box abutments or box anchorage means com risingspaced

cars

18 and 19. There are t ears shown and they areadapted to anchor .the connecter in the box hole against longitudinal displacement. Two of the anchorage ears. say 19, may be formed in circumferenti-al alignment while the other car 18 is spaced from the ears 19 a distance about equal to the thickness of the box wall B and in this way the box wall rests on the seat 16 between the'ear 18 and ears 19. Hence the abutment or anchorage means 1819 are disposed on the outside and inside ofthe box wall and anchor the connecter a ainst longitudinal displacement so long as t e connecter seat 16 en ages the box hole edge.

he overhanging portion of the connecter carries the eccentric box hole edge seat 16 .and

abutment cars

18 and 19 above or opposite the cut away end edge 14 as shown. Furthermore the elongated or overhanging portion includes a screw support lip 21 in which a threaded screw ho 22 is preferably'made at an angle to the axis of the connecter member 12 and the box hole H. Operating means such as a screw 23 is mounted in the threaded hole 22 and the axis of the screw is directed at an angle to the box wall B whereby the force delivered by the screw is ina direction toward the exposed box liole edge portion which is opposite the arcuate seat 16 and screw 23.

The overhanging screwcarrying lip 21 is disposed between the outside box ears 19 and preferably has parallel sides. The parallel sides of the-lip 21 in efiect define slots 10 between the ears 19 and the lip 21. The slots 10 are directed along a plane parallel to the axis of the screw 23 for slidable and guided reception of an improved cable clamp 24 made substantially U-shaped and includes parallel clamp legs 24 which slidabiy straddle the lip 21. The parallel sides of the lip 21,

form a guide on'which the cable clamp 24 slides up and down in relation tothe cable.

A free or unthreaded screw hole 17 is made in the top or head of the clamp for the free reception of the screw 23 which slidabl'y retains the clamp 24 in place. clamp 24 has its lower ends formed at an angle to the axis of the screw and turned inwardly to form fiat pressure feet as indicated at 25 and the clamp legs are pointed at 26 on their front ed i. e., the forward edge 26 The cable lot is made in the orm of a beveled or sharpened edge. The flat ends 25 of the cable clamp are disposed inse arated relation but stand parallel to the ca le C so as to bear against the cable when the clamp is tightened in final fixed position. The cable clamp 24 is loose on the screw 23, the screw hole 17 being large and loose,.so as to adjust itself and tilt to dig the forward edge 26 into the cable should an outward pullingforce be exerted thereon as illustrated in Figure 4. v

The clamp 24 being placed and guided astride the screw carrying lip 21, moves up and down in guided relation in the grooves or slots 10 formed'between each ear 19 andthe clamtp prevents the screw end from engaging cable and crushing it. In other words, the pressure or cable clamp feet 25 of the cable clamp first reach and grip the cable 0 between said feet .25 and the exposed box hole ed e H and accomplishes this purplohse before e screw has reached the cable. e screw is preferably just long enough to be screwed well into or substantially through the overhanging lip 21 atthe time. the cable clamp 24 has reachedfirmly seated engage-.

ment against the cable C.

The parallel flat clamp plates or legs 24" may be disposed in substantially parallel planes and which planes are also about parto bridge over the convolutions of spirally wound metal-armored cable and therefore a positive grip is secured on the cable whether smooth fiber covered or-convoluted. Furthermore, the plates 24 and pressure feet 25 are stamped out of relatively thin stock and their front edges 26 present sharp ortions which burr onto the cable to grip an hold.

. The pressure developed by the screw 23' and imparted to the cable clamp 24 very ositiv'ely seats the cable C against the exposed box hole edge H and the reaction from the force produced by the screw causes the connecter seat 16 to be forced against the box hole edge with the

cars

18 and 19 bearing against the inside and outside box wall surface to thereby anchor the cable connecter 12 against any possible longitudinal displacement. It is the disposition of the box anchorage means 18-19 which anchors the connecter in the box at the same. time the operating means 23 functions to gri the cable. The cable clamp front edges 26 urr, squeeze and press into the cable especially so if there is any tendency for the cable to be pulled from the box because a jerk or force on the cable'i-n the direction of the arrow Figure 4 tilts or levers the clamp 24 rearwardly about the screw as a pivot thereby more deeply embedding the clamp edges 26 into the cable, Inwiring and building construction, it frequentl 118.}?6115 orce ' that a cable is subjected to a jer 'ng inside the by reason of a workman accidentally stepping on or dropping material on a cable, but this connector is found to tighten up when that ha pens.

Anot er feature to be observed is that the clamp biting edges 26 and feet 25 overlie the cut away edge 14 and hence overlie the exposed box hole edge portion left uncovered thereby. In other words the clamp feet extend throu h the box hole H from outside to Imx and this is accomplished by the angular setting of the yoke clamp 24 in respect to the cable axis which laces the head 20 of the clamp yoke outside t e box but disposes the pressure feet 25 inside of the box.

It is noteworthy that the clamp edge 26 1 and pressure feet 25 which are opposite" the headed end 20 of the clamp, afford two spaced '2 parallel cable 'grippin portions which'bear on the cable to each si e of the center thereof. In other words, the two spaced gripping foot portions 2526 bear on each si e of the axis of the cable as distinguished from bear- 'ing directly on the'top or center of the cable a which is common in the art as far as metal,

armored spirally wrapped cable is concerned and which is more li ely to crush the metal armored cable when that is used than when bearing or gripping all the way across the cable as characteristic of this invention. By delivering the grippin force to the side of and fully across the cab e very nearly tangent 'to the circle defining thecable, it follows that there exists less danger of crushingthe cable than "when deliverm the force centrally thereon; and by delivering the clamping force to two sides of the cable in a tan ential manner and bodily across the cable it ollows that one force opposesthe other and there exists no tendency to'rotate the cable because the force of one gripping plate 24 opposes that of the other. T ese features afford advantages in the several ways explained. I

An important feature of this invention resides in ground wire connecting means of a simple and positively working character. In some speclal types of electrical cable 0 which contain the usual circuit wires W, there is also provided a special ground wire GW to safeguard against short circuits and to ground or carry off stray potential. The cable C shown herein is what is known as fiber armored cable and contains a third wire GW which is'usually a bare wire and can be torn out through the cable by forming a slit S in thecable as shown in Figure 6 whereupon the wire GW. is curled around andunder the head of the screw 23. The other end of the ground wire GW is suitably connects ed to any grounded object.

In order to afford a suitable ground wire seat .on the connecter to receive the torn-out ground wire end, the head 20 of thecable clamp 24 is struck u to form wire retaining ears 3, about two 0 which being oppositely disposed in relation to the screw 23, are adequate to hold the ground wire under the screw head as it is tightened. The screw 23 serves ed thereby. v The U-shaped cable clamp therefore has a headed end 20 wa with struck-up em a of the U-s ha against the expose head 23. The ears 3 positively hold the curl of wire formed on the ground wire GW and prevents its displacement when the screw is tightened down on the wire curl or loop placed under the Screw head.- The other end clamp 24 may or may not be formed wit pressure jaws 25, dependin somewhat on thecharacter of cable used an kindof work to be performed.

1 The connecter'is mountedin the box b a tilting action and by angularly introducmg the connecter 12 through the box hole until the inner ear 18 has been inserted, whereupon the connecter is straightened up with the abutment end ed e 14 resting against the box wall surface 81K? with the connecter seat 16 against the box hole edge. The mechanic may now hold the connecter with one hand while he introduces the cable C with the other and thereafter tightens up the screw 23 and thus presses the clamp 24-25 against the cable to complete the box assembly.

The foregoing description discloses a cable connecter of a type wherein the box hole edge H is artly exposed by the connecter when pla in the box hole. This type of connecter dro s out of'place unless held by ones hand unt' the cable C is inserted. To obnate this diflicnlt a connecter support spring 27 may be attac ed to the shorter portion 0 the connecter member and the spring 27 overhangs the end ed 14. Spring 27 rests box hole edge portion and may to' advanta hook around the box wall as shown in Figure 5. This arrangement holds the connecter 12 inplace without the aid of the mechanics hand. The spring 27 yields or bends upwardl sothe connecter may be tilted and pressed ownwardly until the car 18 slips through the box hole, whereupon the spring 27 reacts and snaps the connecter seat 16 up against the box hole edge and holds the connecter in place thereby freeing ones hand for other work. The advantage of the spring 27 is obvious and it is mentioned but not claimed herein.

In both formsofythe invention, the head 20 of the cable clamp is advantageously engaged by the head of the screw 23 which rives the parallel clamp lates 24 and their jaw plates and jaw-like eet 25 against the cable surface, and the proximate surfaces of the screw head and the clamp head 20 are parallel and evenl engaged each other. Although the loose tting screw hole 17 allows the clamp'jaws'25 to wobble or tilt in relation to the screw, the flat screw head en ages the clamp head 20 and straightens up t e clamp lates 24 causingthem to force their jawke pressure members 25 against the surface I of the cable, bridgin over the convolutions of the cable when spiral cable is used due to the reach .or length ofthe jaw-like portions The modified form of connecter comprises I a sleeve having a shoulder 31 and a screw threaded neck 32 with a lock nut 33 which anchors the connecter 30 in the box B. In

all other respects, a cable clamp 34 used on the connecter 30 is similar or the same as that theretofore described and is actuated by a screw 35 so as to drive the inner clampinjaw ends 36 into the cable. The U-shape or yoke clamp 34 straddles a lip 37 and slldes in guide-ways or slots 38 formed in the sleeve at each edge of the Ii 37. The clamp 34' is free and in effect tilta le' on the screw 35 and any force exerted on the cable tending. to dislodge it from the box causes the front edge 36 of the two clamp legs 34 to diginto the cable armor and by a leverage action the front edges 36 increase their digging-in effort and thereby positively secure the cable in the box. v

In this second form of construction just described, the screw 35' rforms two'purw posesonly, that of actuating the cableclamp and that of electricall connecting the ground wire GW to the ca le connecter since the box anchorage means 32-33 is qulte independent of the screw 35. However in the first form of construction, it is clear that the box anchorage means 1819 is dependent on the screw 23 to render efiective said anchor- 1. In a connecter, a member adapted to fit in a .box hole and means to anchor it therein, a yoke-shaped clamp including a head and parallel legs slidabl mounted on the member, a screw assed reely through the head and thread through the member, and

at least one ground wire ear formed on thehead and directed upwardly therefrom in a direction opposite to that of the le" 2. In a connecter, a member an means to anchor it in a box, a clamp includin spaced. parallel plates formed at right ang es on a head and ears struck-up from the head be-'.

tween the plates and projecting in an opposite direction therefrom, a scr'ew loosely mounted through the head between and parallel to the lates and between the ears and said screw in threaded through the member toward a cab e received into the box,

and said lates bein slidably mounted in connecter memberand engaging the clamp openings ormed in t e member and having to force the clamp into the connecter member ends opposite the head which grips the cable. and clamp the cable therein.

3. A connecter comprising a member ada ted to fit into a box hole and meansto am: or it therein, a cable clamp comprising parallel plates to engage a cable received into the box, a ressure foot turned inwardly on the end of eachplate and bearing on the cable, the other ends of the plates being .in-

tegrally formed on a head which is disposed at right angles thereto and the head being disposed in spaced relation from the pressure feet, a 1i formed on the member and mounted withm the cable clamp between the head and ressure feet, and a screw loosely mounted t rough the head and pointed toward the pressure feet and threaded through the lip.

member adapted to receive a cable to be clamped therein, a clamp carried by the. connecter member including, parallel plates disposed parallel to and upon either side of the 26 axis of the cable to be clamped withinthe connecter, a cable clamping foot formed upon the end of each parallel plate and directed inwardly from the plates, and operating means carried by'the connecter member and 30 engaging the clamp to force the clamp into the connecter member and clamp the cable therein. 5. A connecter comprising a connecter sleeve adapted to receive a cable to be 83 clamped therein, a pair of spaced and parallel slots in the connecter sleeve, a clamp carried by the connecter sleeve including, parallel plates having a connecting head with v a hole therethrough, each plate passin a through a slot and disposed parallel to an upon either side of the axis of the cable to be clamped within the connecter, acable clamping foot formed upon the end of each parallel plate and directed inwardly from the plate, and an operating screw passing through the hole in the head of the clamp and threaded into the connecter sleeve between the slots to force the clamp into the connecter sleeve and clamp the cable therein.

I! 6. A connecter comprising a connecter member adapted to receive a cable to be clamped therein, a clamp carried by the connecter member including, parallel plates disposed parallel to and upon either side of the II axis of the cable to be clamped within the connecter member,'the parallel plates being also directed at an angle to the axis of the cable with the ends of the plates directed inwardly within the connecter member, a cable clamping foot formed upon the end of each parallel plate and directed inwardly from the angle to the edge of the plates so that thefoot is parallel with the cable within the connecter member, and operating means carried by the 4. A connecter comprising a connecter plate, each foot being bent at an In testimony whereof I afiix GEORGE C. TH

ature.