US3889048A

US3889048A - Electrical connector and clip therefor having barbs to ensure proper preassembly

Info

Publication number: US3889048A
Application number: US428137A
Authority: US
Inventors: John Elmer Groth
Original assignee: Erico Products Inc
Current assignee: Erico International Corp
Priority date: 1972-10-04
Filing date: 1973-12-26
Publication date: 1975-06-10
Anticipated expiration: 1992-06-10

Abstract

An electrical connector device of the compression fitting type comprises a body of relatively soft material, which body has at least one slot therein formed with substantially smooth planar side walls, and a resilient omega-shape clip member formed of relatively hard material having a central curved or U-shape portion and outwardly bent, oppositely directed legs with sharp terminal edges. The central portion of the clip is initially constricted and inserted into the slot until the legs overlie the edges of the slot with the constricted curved portion of the clip holding the same in place by exerting spring pressure against the planar side walls of the slot. The clip may be further held in such initial or first position by sharp burrs and/or barbs on the outer surface of the curved portion of the clip, such burrs and/or barbs biting into the slot side walls to resist withdrawal of the clip from the slot. A conductor or cable may then be inserted into the curved portion of the clip in its first position, with inwardly directed pressure on the conductor further constricting the clip to permit inwardly directed movement of the same until the curved portion of the clip bottoms in the slot and partially surrounds the cable with the legs of the clip in such position being received in the slot, the inherent spring pressure created by the constriction of the clip then driving the sharp edges of the clip legs into biting engagement with the slot side walls to retain the clip and partially surrounded cable in the slot in such second, fully inserted position.

Description

United States Patent Groth ELECTRICAL CONNECTOR AND CLIP THEREFOR HAVING BARBS TO ENSURE PROPER PREASSEMBLY [75] inventor: John Elmer Groth, Cleveland Heights, Ohio [73] Assignee: Erico Products, Inc., Cleveland,

Ohio

[22] Filed: Dec. 26, 1973 211 Appl. No.: 428,137

Related US. Application Data [63] Continuation-impart of Scr. No. 298,769, Oct. 4,

i972, abandoned 52 U5. c1 114/94 R; 29/628; 114/90; 339/276R 51 1m. c1 ..H02g 15/08 [58] Field of Search 174/71 R, 90, 94 R, 84 C; 339/276 R; 29/628, 630 F {56] References Cited UNITED STATES PATENTS 2,964,585 l2/l960 Nilsson et al. l74/94 R 3,032,603 5/1962 Whitley l74/94 R Primary Examiner-Darrell L. Clay Attorney, Agent, or Firm-Donnelly, Maky, Renner & Otto [57] ABSTRACT An electrical connector device of the compression fitlll] 3,889,048

[ 1 June 10, 1975 --"initially constricted and inserted into the slot until the legs overlie the edges of the slot with the constricted curved portion of the clip holding the same in place by exerting spring pressure against the planar side walls of the slot. The clip may be further held in such initial or first position by sharp burrs and/or barbs on the outer surface of the curved portion of the clip, such burrs and/or barbs biting into the slot side walls to re sist withdrawal of the clip from the slot. A conductor or cable may then be inserted into the curved portion of the clip in its first position, with inwardly directed pressure on the conductor further constricting the clip to permit inwardly directed movement of the same until the curved portion of the clip bottoms in the slot and partially surrounds the cable with the legs of the clip in such position being received in the slot, the inherent spring pressure created by the constriction of the clip then driving the sharp edges of the clip legs into biting engagement with the slot side walls to retain the clip and partially surrounded cable in the slot in such second, fully inserted position.

3 Claims, 13 Drawing Figures PATENTEUJUH 10 ms ELECTRICAL CONNECTOR AND CLIP THEREFOR HAVING BARBS TO ENSURE PROPER PREASSEMBLY CROSS REFERENCE TO RELATED APPLICATION The present application is a continuation-in-part of my co'pending application Ser. No. 298,769, filed Oct. 4, i972, now abandoned.

BACKGROUND OF THE INVENTION The invention relates to connectors for physically and electrically coupling together electrical conductors, such as wires, cables, or the like, and more specifically relates to such a connector of the compression fitting type.

Prior art electrical connectors for coupling together two or more conductors of the same or different sizes have included H-frame type compression fittings or bodies having slots into which respective conductors are inserted, with the fitting being crimped by a pressure applying tool to maintain the conductors in pennanently connected relation within the connector. Such prior art electrical connectors have been difficult to install because the conductors tend to slip from the connector slots during the coupling or crimping process. The problem arises because the crimping process usually requires both hands of a lineman who is often in a precarious position on a power pole, for example.

Thus, it has been desired to provide a mechanism for temporarily maintaining the respective conductors in position in the slots of the connector before and during crimping to facilitate such installation. One prior art connector has a fold down tab partially blocking the mouth of the slot temporarily to confine the conductor therewithin, but in using this device difficulties have been experienced when the tabs inadvertently break or when the tabs do not sufficiently confine the conductor in the slot. Another prior art connector that maintains the conductors in place during crimping is described in Whitley US. Pat. No. 3,032,603. Such patent discloses a complex spring clip member of generally U-shape configuration having two pairs of wrinkles or crimps in the legs thereof, such clip initially being held in the slot by the first pair of wrinkles interfitting with correspondingly formed grooves in the side walls of the body slot. in such position, a conductor may be inserted into the clip to urge the same further into the slot thereby causing the second pair of wrinkles to seat in the side wall grooves to hold both the clip and the conductor in place. Such device, while useful in the field, will accept only a small range of conductor sizes for a given slot and clip combination. Also, such prior art connectors have been relatively expensive and difficult to manufacture requiring special care to form the respective slot grooves, complex clips and/or associated tabs.

Accordingly, a primary object of the invention is to provide an electrical connector that facilitates the joinder of variously sized conductors.

A further object of the invention is to provide an electrical connector and an associated clip member that are easily manufactured.

Another object of the invention is to provide an electrical connector of the compression fitting type that facilitates coupling two or more conductors by retaining at least one of the same in position in the connector during crimping or other compression operation.

Still another object ofthe present invention is to provide projections on the outer surface of the curved central portion ofthe clip that are operative to bite into the side walls ofthe body slot when the clip legs overlie the edges of such slot, thereby positvely to resist withdrawal of the clip from the slot.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinatter fully described, the following description and the annexed drawings setting forth in detail certain il- Iustrative embodiments of the invention, these being indicative. however, of but several of the various ways in which the principles of the invention may be em ployed.

DESCRIPTION OF THE DRAWNGS In the annexed drawings:

FIG. I is a perspective view of an electrical conncctor according to the present invention crimped together with conductors fixed therein;

FIG. 2 is an end elevation of an electrical connector in accordance with one embodiment of the invention showing the clips preassembled in theirfirst position;

FIG. 3 is an end elevation of the electrical connector of FIG. 2 showing conductors positioned in the clips;

FIG. 4 is an end elevation of the electrical connector of FIG. 3 prior to crimping showing the resilient clip members fully inserted in the slots with the conductors positively retained and the cutting edges of the clip in biting engagement with the slot side walls;

FIG. 5 is an end elevation of an electrical connector showing another embodiment for the resilient clip member of the present invention;

FIG. 6 is an end elevation of an electrical connector with a substantially closed opening at one end and a substantially open slot and resilient clip member in the other end;

FIG. 7 is an end elevation of the resilient top clip of the embodiment Of FIGS. 2-4 in its undeformed condition prior to preassembly;

FIG. 8 is an end elevation of an undeformed resilient clip having burrs on the outer face of the central curved portion of the clip;

FIG. 9 is an enlarged end elevation of an undeformed resilient clip having outwardly directed barbs on the external surface of the central curved portion of the cli extending toward the clip legs;

FIG. 10 is a broken away elevation taken along line 10-10 of FIG. 9 showing the barb or tab;

FIG. 11 is an end elevation showing the clip of FIG. 9 in its initial slightly constricted position in the slot of the connector body with the barbs biting into the planar side walls of the slot to assist in retaining the cli in such position;

FIG. 12 is an end elevation similar to FIG. 11 showing conductors inserted in the curved portion of the clip in the initial position of the latter; and

FIG. I3 is an end elevation of the embodiment disclosed in FIG. 12 with the clip in its fully inserted second position wherein the terminal edges of the clip legs bite into the slot sidewalls.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings wherein like reference numerals refer to like elements and initially to FIG. 1, an electrical connector 10 is shown joining together two conductors II, 12 in permanent electrically c0nductive and physically connected relation. The respective conductors may be single strand wire, or. as shown, multi-strand cables of the same or different sized wires with each connector being capable of receiving conductors over a range of sizes, whereby a limited number of connector sizes is capable ot'joining numerous conductor combinations. As illustrated in FIG. I, the electrical connector is in the fully assembled or crimped condition with the pairs of securing -

end portions

13 and 14 being closed over the conductors 11 and 12, respectively, to hold the same in position in the connec- [01.

Referring now to the embodiment disclosed in FIGS. 24 and 7, an H-frame compression fitting electrical connector indicated generally at 15 has a main body portion 16 formed of relatively soft material, such as aluminum or copper. Such body 16 is formed with opposed, inwardly directed U-shape slots l7, 18. The

side walls

19, 20 of the respective slots are smooth and planar, and the

terminal edges

21, 22 of the respective securing

end portions

23, 24 ofthe body 16 form the Outermost edge of the slot as well as the terminus of the connector. Resilient, generally omega-shaped clips 25 having a central curved or U-shape section 26 and outwardly directed, oppositely

bent legs

27, 28 are opera tively associated with the slots of such connector as described in detail below. Each clip member 25 is formed of relatively hard material, such as spring steel, stainless steel, phosphor copper, or beryllium copper, and the oppositely directed

clip legs

27 and 28 have sharp

terminal biting edges

31 and 32, respectively.

Since the opposed slots and clips of the first embodiment are of the same general configuration and vary only in size, the top slot and clip will be described hereinbelow with the understanding that such description likewise applies to the opposed bottom slot and clip of such embodiment.

The resilient clip member 25 is initially positioned in slot 17 by slightly constricting the central portion 26 of clip 25 from the undeformed FIG. 7 configuration to allow insertion ofthe clip until

legs

27, 28 rest upon the edges 21 of the slot. In such position, the spring clip is retained in the slot by the central curved portion 26 of the spring clip naturally resiliently expanding to bear against the side walls 19 of the slot frictionally to hold such clip in such first position.

Turning now to FIG. 3, the electrical connector previously described with reference to FIG. 2 is shown with conductor inserted in the central curved portion ofthe omega-shape clip member 25. Conductor 35 may then be forced inwardly by the lineman until the clip is fully positioned within the slot 17 as shown in FIG. 4. During the movement between the FIG. 3 and FIG. 4 positions, the

legs

27 and 28 of the clip are drawn within the confines of the slot and, due to their length, the legs bearing against the slot side walls act to further constrict the central curved portion 26 of the clip, thereby partially to encircle and thus retain conductor 35 at the bottom of the slot. In such final FIG. 4 position, the sharp

terminal edge portions

31, 32 of the

clip legs

27, 28 bite into the relatively smooth soft side walls 19 of the slot 17 to maintain the clip 25 firmly in position within such slot.

It will be appreciated that in the embodiment shown in FIGS. 2-4 and 7 the bottom slot 18 is of slightly reduced dimensions to accommodate a conductor 36 that is diametrically smaller than conductor 35. Accord- 4 h1gly,clip37issimilarlysmallerbutfunctionsin exactly the same manner as clip 25, with the final result being the partial encirclement of conductor 36 at the bottom of slot 18 while the terminal edges of the clip legs bite into the planar side walls of the slot.

In operation of the invention as depicted in FIGS. 1 through 4 and 7, the electrical connector 15 is provided with the

resilient clip members

25, 37 positioned in the slots l7, 18 thereof with the legs of such clips overlying the edges of the slots and with the slightly constricted centrally curved portions of such clips applying spring pressure against the slot side walls frictionally to hold such clips in the first position.

Respective conductors

35, 36 are then inserted into the centrally curved portions of the thus positioned ellp members, either one conductor at a time or both simultaneously, and the respective conductors are then pushed or snapped into the respective slots thereby to cause at least a section of the centrally curved portions of the clip members to fold partially around the respective conductors as the sharp edges at the terminal ends of the clip legs bite into the

walls

19, 20 of the slots to maintain the respective conductors in position in the connector. Once the conductors are thus secured, a crimping tool or other pressure applying means may be used to crimp or otherwise deform the connector pennanently to secure the conductors therein.

Referring now to FIG. 5, a second embodiment of the electrical connector 15 has a clip member disclosed wherein the central portion 39 of the clip 40 has two

bends

41, 42 at each side thereby to form a central curved portion 43, two

straight sides

44, 45 and two outwardly bent, oppositely directed

legs

46, 47. The central portion 39 of clip 40 is initially slightly constricted to permit insertion of the same into slot 17 until

legs

46, 47 overlie and rest upon the edges of the slot. In such position, the constricted central portion of the clip naturally resiliently expands to permit bends 41 of the clip frictionally to engage the side walls 19 of the slot to hold the clip in such first position, with the two bends 41, 42 in each clip side wall acting to concentrate the spring pressure retention force while providing partial preclosure of the central portion of the clip.

A conductor may then be placed in clip 40 and pushed inwardly to force such clip further into slot 17 until further movement is restricted. As shown by the fully inserted clip 49 in the bottom slot 18 of connector 15, such pushing or snapping movement results in

legs

46 and 47 being drawn into the slot further to constrict

straight sides

44 and 45 to enfold about the conductor for retention of the same. At the completion of the clip insertion, the central portion of the clip 40 naturally resiliently expands to drive the terminal cutting edges of

legs

46 and 47 into biting engagement with the smooth planar side walls of the slot firmly to hold the clip in position. In addition, the bends 41 of the clip in such inserted position exert spring pressure against the slot side walls 19 to assist in retaining the clip in the second position. When the two conductors have thus been fully inserted, the ends of the connector may be crimped to complete the connection.

Turning now to FIG. 6, an electrical connector 51 is shown having a generally open U-shape top slot 52 with relatively smooth planar side walls 53 and a substantially cylindrical bottom opening 54. A resilient omegasltaped clip member 55 similar to the clip members described above is positioned in the slot 48. The cylindrieai opening 54 in the connector 51 extends the length thereof and is closed by

closure portions

56, 57 formed as an integral part of the connector. In this embodiment, one of the conductors to be connected may be sli ed axially through the opening 50in the connector and thereby held in place by the

closure portions

52, 53 while the other conductor may be snapped into place using the resilient clip member 55 as described above. Of course, once the conductors are in position, the Connector may be crimped closed to secure the conductors therein. This particular embodiment is especially useful when a terminal portion of one conductor is intended to be connected to a central portion of a second conductor, the former being inserted into the opening 50 and the latter being snapped into the slot 48.

Referring now to FlG. 8, a third embodiment ofa resilient omega-shape clip is disclosed. Such clip 58 includes a central curved portion 59 and two outwardly bent, oppositely directed

legs

60, 61 having sharp

terminal edges

62, 63, respectively. At least the laterally external surface of curved central portion 59 adjacent the clip legs is provided with a series of burrs 64, which for clarity of understanding have been enlarged in FIG. 8. Such burrs may be provided, for example, by die cutting the clip and leaving the naturally resulting burrs in the desired area rather than subjecting such area to the normal finishing operation.

When the central section of clip 58 is slightly constricted for insertion into its first position wherein

legs

60 and 61 overlie the edges of the connector slot, burrs 64 will bite into the smooth planar side walls of the slot upon the natural resilient expansion of such clip, thereby to assist in holding the clip in such first position. Such biting engagement between burrs 64 and the smooth planar side walls ofthe slot serves to resist withdrawal of clip 58 from the connector slot and also serves longitudinally to stabilize the Clip Within such slot. When clip 58 is fully inserted into the connector slot, the terminal cutting edges 62 and 63 oflegs 60 and 61 bite into the side walls of the slot to retain the clip in such fully inserted position, with the burrs 64 being removed from engagement with such sidewalls due to the further constriction ofthe centrally curved portion 59.

Referring now to FIG. 9, yet another embodiment of an omega-shaped resilient clip according to the present invention is illustrated. Such clip 66 similarly includes a centrally curved or U-shape portion 67 and oppositely directed, outwardly

bent legs

68 and 69 having sharp

terminal edges

70 and 71, respectively. The sides of the centrally curved portion 67 are provided with outwardly directed projections or

barbs

72 and 73 extending toward

legs

68 and 69 and having sharp tenninal edges 74 and 75, respectively. As shown in FIG. 10, such barbs are formed by making a centrally positioned three-sided incision 76 in the side wall and by then bending the included strip material outwardly to its final FIG. 9 position.

Referring now to FIG. 11, the central portion of clip 66 is initially slightly constricted and inserted into slot 78 of connector 79 until oppositely directed

legs

68 and 69 overlie and rest upon

edges

80 and 81, respectively, of the slot 78. in such position, the centrally curved portion 67 naturally resiliently expands so that such section engages the planar side walls of slot 78

adjacent legs

68 and 69, thereby to exert a spring pressure on such slot side walls frictionally to hold the clip 66 in its initial FIG. ll position. Such natural outwardly directed expansion ofthe resilient clip also results in the sharp terminal edges 74 and 75 of

barbs

72 and 73, respectively, biting into side walls 82 of slot 78. Such biting engagement acts positively to retain the clip 66 in its first position, thereby to resist withdrawal of the clip and further to longitudinally stabilize such clip in slot 78. The barbs or

projections

72 and 73 are inclined toward

legs

68 and 69 so that inwardly directed movement ofthe clips in the slots will not be resisted by such barbs but a positive interlocking will be formed to resist outwardly directed movement.

Referring now to the sequence disclosed in FIGS. 12 and 13, a conductor 84 may be inserted into the concave opening presented by centrally curved portion 67 of clip 66. The lineman may then force conductor 84 inwardly until the bottom of the U-shape central portion 67 seats on the base oi slot 78. Such inwardly directed movement of the clip 66 results in

legs

68 and 69 being drawn within the confines of slot 78, thereby to bear upon the sidewalls of the slot to force the

barbs

72 and 73 out of biting engagement and further to con strict such U-shape central portion to enfold about conductor 84 as disclosed in FIG. 13. When the spring cli 66 is in its innermost position, the clip naturally resiliently expands to drive the sharp terminal ends and 71 into biting engagement with the smooth planar side walls 82 of slot 78, thereby positively to retain the clip in its final position with the conductor at least partially enclosed therewithin.

As illustrated, the second conductor 86 for connector 79 is slightly diametrically smaller than conductor 84 so that the bottom slot 88 in such connector is similarly geometrically reduced. Accordingly, clip 89 is also of reduced dimensions but operates in the same way to result in conductor 87 being partially enclosed for retention by the constricted, central curved portion of the clip 89 while the tenninal edges of the oppositely bent outwardly directed clip legs bite into the side walls of slot 88. Once the conductors have been positively secured by the clips in the slots as shown in FIG. 13, the connection of the conductors is completed by using a crimping tool to close such slots.

lt will be appreciated of course that the burrs 64 shown in FIG. 8 could similarly be used with the barbs or projections of the embodiments disclosed in F IGS. 9 through 13, as illustrated at 40 in FIG. 9. Such an arrangement of parts would permit the clip to be held in the first position by spring pressure exerted by the constricted central portion of the clip, by biting engagement of the barbs 64 with the side walls of the groove, and by further biting engagement by the barbs with such side walls.

Thus, it should now be understood that the body of the electrical connector of the invention may be easily manufactured from a relatively simple extrusion or similar process without requiring more complex dies to provide grooves within the slots as necessitated, for example, in the prior art connectors. The resilient clip members also may be easily formed, for example, by a simple stamping process because the clip members do not require complicated wrinkles or bends therein. Since the clip member is fonned of relatively hard material, the sharp edges occur as a normal result as the member is stamped, or otherwise cut from a larger piece of material further facilitating its manufacture. 'lhe simplicity of the slot and clip design also facilitates the ease of design for extended range of conductor sizes.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An electrical connector comprising a deformable relatively soft body having at least one conductor receiving slot therein, which has smooth planar side walls, an omega-shape resilient clip in said slot having a curved central portion and outwardly bent oppositely directed legs, said legs overlying the edges of said slot while said clip is held in said slot by spring pressure of the constricted curved central portion of said clip, said central portion of said clip having sharp projections biting into said planar side walls of said body resisting withdrawal of said resilient clip from said slot. the legs of said clip terminating in relatively sharp hard edges whereby when said clip is forced into said slot by a conductor, the body of said clip will enfold about the conductor while the sharp hard edges bite into the walls of such slot holding the conductor in such slot. said sharp projections being barbs struck from the sides of the curved central portion of said clip and projecting symmetrically one on each side of the clip outwardly of said slot at an angle to the walls thereof and having sharp terminal ends biting as aforesaid into the planar sidewalls of said body.

2. The electrical connector of claim 1 wherein burrs are provided on the outer face of the central portion of the clip also biting into the sidewalls of the slot.

3. The electrical connector of claim 1 wherein said barbs are struck from the central portion of the sides of the clip by a three-sided incision.

i Q i l

Claims

1. An electrical connector comprising a deformable relatively soft body having at least one conductor receiving slot therein, which has smooth planar side walls, an omega-shape resilient clip in said slot having a curved central portion and outwardly bent oppositely directed legs, said legs overlying the edges of said slot while said clip is held in said slot by spring pressure of the constricted curved central portion of said clip, said central portion of said clip having sharp projections biting into said planar side walls of said body resisting withdrawal of said resilient clip from said slot, the legs of said clip terminating in relatively sharp hard edges whereby when said clip is forced into said slot by a conductor, the body of said clip will enfold about the conductor while the sharp hard edges bite into the walls of such slot holding the conductor in such slot, said sharp projections being bArbs struck from the sides of the curved central portion of said clip and projecting symmetrically one on each side of the clip outwardly of said slot at an angle to the walls thereof and having sharp terminal ends biting as aforesaid into the planar sidewalls of said body.