US2475574A

US2475574A - Conduit connector

Info

Publication number: US2475574A
Application number: US721404A
Authority: US
Inventors: William H Taylor
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-01-10
Filing date: 1947-01-10
Publication date: 1949-07-05
Anticipated expiration: 1966-07-05

Description

July 5, 1949. w. H. TAYLOR 2,475,574

CONDUIT CONNECTOR Filed Jan. 10, 1947 2 Sheets-Sheet 1 July 5, 1949. w. H. TAYLOR CONDUIT CONNECTOR 2 Sheets-Sheet 2 l Filed Jan, 10, {L947 @7'7'07M e g Patented July 5, 1949 a STATES PATENT OFFICE "11 Claims.

"The present invention relates to electric cable connectors and is concerned more particularly with the problemof anchoring flexible jacketed electric cable and its manner of securement to junction-and fixture boxes.

.It is .a principal object of the present inventionitorproduce an electric cable connector com- :prisedofa minimum number of component parts which maybe-employedtoeifectively and securely ,join themetallic jacketing of the so-called B-X type to the. flanges ofjunction, service and fixture boxes andtat the same timefulfill the require- .ments of sound code and engineering practice in safeguarding against inadvertent disconnection, .installationfailures, and other performance con- .siderations.

,;Further objects @of the .present invention are :toyproduce electric .conduit connectors which can be. quickly and conveniently.installed-with a minimum number of tools and without requiring :special skill.

InrB-Xconnectors heretofore known, there was .providedscrew clamping portions which required .preliminary fixation adjustments. and the use of a considerable amount of time by electricians and servicemen in performing-a screw tightening operation; after which andupon being inserted into the .junction -.or service-box, the coupling member required further "screw threading attention :precededby a troublesome application of a lock- .ing nutathat had to'be inserted over flaring termi- ;.nal .wiresoandstarted on the coupling threads .HIIGBIH-COIIGitiOHS frequently adverse and at best inconvenient. Other approaches towards solving this'problem with non-threaded components were I .attended "With eccentric placement of the cable with: respect to the box openings, bodily camming 10f thelconnector -with respect tothe box by eccentric .dislodgement, and numerous other conse- .qruent-eifects deemed tobe less desirable and more :troublesome-than-theconditions incident to the \installation practices required in accordance with -thepresent invention.

For a more comprehensive understanding of thiseinvention reference will now be had to the accompanying-drawings and to the following de- .tailed specification in -which like reference characters-designate corresponding parts throughout, sand-in which Fig. lisa plan view of ajunction box. partially lins'section having a connector coupling according .to the. present invention applied thereto;

..Eig.-2-is a'sectional viewtaken approximately .on line -.2-.2 of Fig. l with the coupling elements and conduit in elevation;

2 Fig. 3*is 'a sectional detail viewtaken approximately *on line 3- -3 ef 'Fig.2;

Fig.- 4 is an enlarged transverse sectional view taken on "line' l- -4 of Fig. 2with-the coupling "elements and conduit insection;

Fig. 5is a correspondingly enlarged transverse sectional viewta'ken approximately on line "5- 5 Fig. 6 is a'perspectiveview of the annular coupling member featuring one side thereof;

Fig. '7 is a corresponding perspective view of the same member illustrated in Fig. 6 featuring features of the;present invention and illustrated as being applied to a junction or service-box "flange, and'as'having a flexible conduit installed therein.

Fig. 10 is a side elevational view of themodifle'd coupling member featured in Fig.9;

'iFig. llis'an enlarged transverse sectional view "takenapproximately on line Il-ll of Fig. '10;

"Fig. l2 is "apl'an view of the modified keyin yoke featured "inthe embodiment illustrated in Fig. 13-is a "plan' view of a'second modified embodiment having incorporated therein certain features 'of' the present invention;

Fig..l4 is a side elevational view with the junction box "partially in section of the second modificationfeatured in Fig.113.

Fig. 15 is an enlarged transverse sectional view taken "approximately on line Iii-l5 of Fig. 14; and

Fig.16 is a perspective view on a reduced scale of the keying yoke featured in the secondmodific'ation ofFigs.'13 11015.

Attention .will now be directed to Figs. 1 to 38 inclusive in which a preferred embodiment of the present invention has been variously illustrated .and in whiChaconventional type of flexible B-X .cable I l isshown which is made of a spiral metallic .jacketing .rolled over, one convolution upon anotherin overlapping manner as best indicated in .Fig. 4,.so "that the overlapping .lip l 2 of one convolution -engages in continuous impingement .theupstandinglipfl of an adjacent convolution. The lip his inwardlyturnedfrom a alargediameterflight .14 .while lip .I3 is conversely outwardly flared frome. smaller diameter flight l5 whereby a .continuous flexible jacketing is ob- .tained. -In.order tosever-the cable at any point in its continuity, the well known practice has been to slash the outer flight M by a transverse cut and to complete the separation by flexing until severance is effected.

Within the metallic jacketing there are usually provided two or more insulated conductors designated it over which is wrapped a fibrous spiral I! that, may be easily torn in order to achieve exposure of the insulated wires |6.

Since the severed end of the metallic jacketing may be rough or irregular it is deemed good practice to insert a fiber thimble I8, Fig. 4, which is provided with a rolled back collar I9, and which because it is open on a vertical element of its cylinder can be quickly and easily inserted, so as to prevent the possible sharpness of the severed edge 2| from coming into contactual engagement directly with the wrapper I1 and thereafter with the insulation on the conductors I6.

The instant problem is one of securing the cable II to the wall or flange 22 of a junction or service box, various types of which are wellknown in electric wiring practice and are provided for encompassing intermediate pieces of equipment, such as, switches, outlets, etc. For effectuating the declared purpose there is provioled herewith various embodiments of coupling elements, all characterized with certain features inherent to the present invention. In Figs. 1 to 7 this coupling element is comprised of a cylindrical and annular principal body designated 25 and a keying yoke generally designated 26.

The principal member 25 may be made of two halves split along a median line as s hown in Fig. 13 or it may be made integral as illustrated. This member consists of a relatively longer portion having a smaller external diameter and a head 21 having a relatively larger diameter, the internal diameter of both being identical as best indicated in Fig. 4 so as to receive the convolutions M of the flexible conduit with sufiicient marginal clearance to allow for moderate variations and to accord with diverse manufacturing practices. In this connection it it to be noted is thereby not critically dependent upon attainment of close chambering or fitting between the flexible conduit jacketing and the internal wall of the connector element.

The inner bore of the principal member 25 is preferably of sufficient depth to admit substantially more than two full convolutions of the conduit as best indicated in Figs. 4 and 11, and in order to secure the conduit longitudinally there may be provided one or two spiral ward segments 28, Fig. 7, proportioned and pitched to conform with the spiral groove 29 of the conduit jacketing i I. Where two such wards 28 are deemed preferable, they may be located in opposition to the approximate point 3i, Fig. 4, where the knife edge 32 of the keying yoke 26 engages the groove 29. This practice may be preferred in order to prevent the conduit H from yelding to an unscrewing torque although it is to be noted that such torque may not be applied once the junction box or corresponding element as well as the B-X conduit section have been anchored or permanently placed. In this regard it is to be noticed that the angle preceding the knife edge 32 may be varied marginally to secure side engagement with the convolution walls and that thereby also disassociation of the parts can be prevented.

The keying yoke 26 may be made of any suitable material consistent with practical requirements and it has been found by test that eve 4 when formed of relatively soft metal such as aluminum, the case hardening formation incident to normal cooling will afford adequate rigidity to prevent distortion in the region of the curvature when the inclined camming edge 32 opposes the normal leg 34 during the efiectuation of the aforedescribed camming action in straddling the jacketing From Fig. 2 it may be observed that the keying yoke 26 is also beveled laterally affording a wedging surface 35 in opposition to its flat surface 36. Accordingly when the key is placed the Wedging surface 35 depending upon its direction of application, will impinge upon one or the other of the inclined surfaces 31 or 38 which define the shallow notching 39, Fig. 6, of the annular member 25.

In order to prevent the conduit II from projecting beyond the coupling element 25, a lip formation ii may be provided, as best indicated in Figs. a and 7, while at opposite sides of the enlarged collar 21, peek-hole notches 42 are formed so that the placement of the insulation piece iii and. its collar l9 can be readily observed for purposes of inspection.

The wedge effect of the two surfaces 35 and 36 impinging as has been said, against the outer wall surface of the box walls 22 and through one of the surfaces 31 and 38 serves to anchor the collar portion 25 securely against the junction box whereby there may be effected more positive grounding for safety and security reasons.

Attention is called to the attainment simultaneously of the anchoring of the collar 26 to the box wall 22 while the knife edge 32 deforms in seatin itself within the spiral groove 29. Variations in manufacturing dimensions may be further accommodated by slight distortion of the yoke 26 during placement. Also, it will be noted that the assembly may be made fast with the yoke 26 and the collar 25 in any preferred angular position with respect to the box wall 22 thus conforming with wide conditions of accessibility such as may be indicated under various accommodations of spacing and surrounding circumthat the success of the instant coupling apparatus stances- In Figs. 9 through 12 there is featured a variation of keying yoke 5| which will afford substantially greater securement tension for holding the coupling collar 25 against the box wall 22. In this modification the yoke 5| may be made of spring metal comparable in physical characteristics to well known lock washer steel and its legs 52 and 53 may be shaped as best indicated in Fig. 10 so that upon insertion, securement is effected by tensioning the legs between the outer surface of the wall 22 and the impingement surfaces 3i and 38 of the

collar notches

39 and 54. By swedging the outer periphery of the yoke 5| as at 55, the element 5| may bite into the surface of wall 22 and thereby resist inadvertent removal effects. The extremities of the legs 52 and '53 turning inwardly as indicated in Fig. 10 also bite into the surface as at 56 serving the same purpose even more effectively.

Since the type of yoke indicated in Fig. 12 may be manufactured by forming methods it is feasible and practical to provide the inner surface of leg 53 as at 51 with anchoring teeth or knurling. The knife edge 58 in this embodiment and particularly where the yoke 5| is formed of steel, may not require the ward formations 28 as in the case of the principal embodiment described above, although it is to be understood that association of these elements may be optionally arranged. I

amma one bent tensioning leg BZ-and a straightleg -GG.

In"th1s 'modificationthe'colla'r 64 mayhave a wide ndtch-"Bt'Flg. 'IL'on' one side and "a "narrow notch"6B,Fig. 13; on its'oth'erside. Both'notches penetrating through to the inner bore 61 whereby by providing knife edges on the inner surfaces of the

yoke legs

62 and 63 there may be efiected a securement with the convolutions of the lacketing ll through the opposed effects of the knife edges on the respective legs. Tensioning against the box wall 22 is attained by the bent leg 62 solely and the offset relationship of the two

legs

62 and 63 may be made to conform with the corresponding ofiset relationship of the spiral recess 29 as best illustrated in Fig. 15.

While the present invention has been explained and described with reference to certain disclosed embodiments, it is to be understood nevertheless, that its scope is thereby not limited and that for an understanding of the range of mechanical equivalency, reference should be had to the hereinafter appended claims.

The invention claimed is:

1. A connector apparatus for securing spiral jacketed. cable to the walls of junction boxes comprising a thimble member having an internal bore for receiving a plurality of convolutions of said spiral jacketed cable, a lip flange for limiting the distance of entry of said cable within said member, a collar for limiting the passage of said member through a hole in the wall of a junction box, said member having at least one segmental opening in its periphery, a camming yoke for strad dling said member and by entering said segmental opening presenting portions for wedging said cable within said member, and portions on said yoke for wedging said member against the wall of a junction box.

2. In an electric conduit connector, a principal member comprised of a cylindrical unit having a concentric bore adapted to receive a jacketed electric cable and provided with a segmental opening, communicating with said bore, protuberance extending within said bore on a side opposite to said segmental opening. a collar flange integral with said member spaced from said opening in correspondance with the wall thickness of junction boxes, and an integral anchoring device to be received within said opening including portions adapted to cam between said principal member and the wall section of a junction box "and other portions adapted to cam a cable within said bore against said protuberances.

3. Connecting means for flexible spirally jacketed conduit cable compr izing, an integral cylindrical member having an external diameter to be received within conventional junction box openings a collar flange for abutting against the adjacent wall section of said openings, and an internal diameter adapted to receive flexible conduit jacketing to a predetermined penetration, said member having a tangential opening, and wedging means for straddling said member and for entering said tangential opening including portions for constricting said cable within said member and portions for wedging between said member and the wall surface of a junction box.

4. A conduit connector comprising a principal member having a cylindrical body and a concentric bore adapted to receive a cable conduit, said body having a tangential opening, lug means formed within said bore on a side opposite said 6 tangential 1: opening, :a rcollar rintegral with :said member predeterminedly :ispace'd them said tangential openin'gysarrd a. keyingidevicei including a portion adapted to cam ibetwe'en 'said lprincipal member: andian object to which said member is secured and another portion adapted to cam a cable conduitwithin"saidbore against said lug 5. Means for connecting flexiblezspirallyjacketed conduit cable to junction boxes or the like, comprising an integral cylindrical main member having an external diameter to be received within conventional junction box openings, a collar diameter for abutting against the wall section adj acent said openings, and an internal bore adapted to receive said. cable to a predetermined penetration, said main member having a tangential opening connecting with said bore, means for straddling said member and for entering said tangential opening including portions for wedging against said cable within said member, and portions for wedging between said member and the wall surface of a junction box.

6. A connector device for B-X cable or the like comprising a thimble portion having a limiting collar and adapted to be received within an opening of a junction box and to in turn receive the terminal portion of a B-X cable, and a keying yoke for straddling said thimble including portions adapted to secure the 3-)! jacketing within said thimble by wedging in one direction between its internal edges said 3-)! jacketing and said thimble portion, and to tension said thimble against a wall section of a junction box by wedging in another direction expansively between said wall section and said thimble portion.

7. The combinations set forth in claim 6 in which at least one leg of said keying yoke is bent or curved longitudinally so as to effect a tension between a surface of said thimble portion and a surface of a junction box into which said thimble is applied.

8. A connector device for securing B-X cable to wall openings of junction boxes or the like comprising a thimble having a predetermined insertion diameter, a limiting collar adapted to abut the wall of a junction box and an internal bore for receiving the terminal portion of a B-X cable, said insection diameter portion including opposed slash openings, and a camming yoke for straddling said slash opening portion of said thimble including angled edges adapted to secure by biting into the B-X jacketing within said thimble and tapering sides to tension said thimble against a Wall section of a junction box.

9. The combinations set forth in claim 8 in which said camming yoke comprises a leg bent so as to effect a tension between a surface of said thimble and a surface of a junction box into which said thimble is applied.

10. In a connector apparatus for securing spirally jacketed cable to junction boxes or the like, a thimble assembly affording an internal cylindrical bore of a predetermined depth for receiving a plurality of convolutions of said spirally jacketed cable, a peripheral flange forabutting the junction box wall whereby to limit the extent of entry therethrough of said thimble assembly, said assembly having at least one opening peripherally thereof, a camming yoke for straddling said assembly and for entering said opening and wedging said cable therewithin and portions on said camming yoke for wedging said assembly against the wall of a junction box.

11. The combination set forth in claim 10 in 7 which said camming yoke includes a. leg member bent so as to effect a retaining tension between a surface of said thimble assembly and a surface of said junction box wall.

H. TAYLOR.

REFERENCES CITED The following referenlces are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Whiton Apr. 8, 1902 Vibb-er Sept. 29, 1908 Kipnis June 18, 1929 Certificate of Correction Patent No. 2,475,574. July 5, 1949. WILLIAM H. TAYLOR It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 3, line 44, for the words connection it it read connection it is; column 5, line 49, claim 2, for correspondence read correspondence; column 6, line 49, claim 8,

for insectlon read insertion;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice. Signed and sealed this 29th day of November, A. D. 1949.

THOMAS F. MURPHY,

Assistant Oommz'ssz'oner of Patents.