US 3787948 A
A wrench for forming pigtail splices in wire nuts between electrical conductors. The wrench has a plastic workhead in the form of a relatively narrow block. There is a wire nut socket running from top to bottom through the workhead, near one end. A thin metal handle extends downwardly from the workhead near the end opposite its wire nut socket end. To form a pigtail splice in a wire nut with the wrench, the wire nut is fitted into the socket in the workhead, and the bare ends of a pair of conductors are then inserted as far as they will go into the wire nut. These conductors are next held tightly with one hand near the wire nut, and the workhead is spun rapidly around the axis of the wire nut socket, by means of the wrench handle, with the other hand. This action twists the wire ends into a pigtail splice and tightens the wire nut firmly in place around the splice.
Description (OCR text may contain errors)
United States Patent [191 Runge WIRE NUT WRENCH  Inventor: Charles H. Runge, 25755 Melba Ave., Homeland, Calif. 92348  Filed: Apr. 7, 1972  Appl. No.1 241,909
 U.S. Cl. .l 29/203 H Primary ExaminerThomas H. Eager Attorney, Agent, or FirmPeter H. Firsht et a1.
[ Jan. 29, 1974 [5 7 ABSTRACT There is a wire nut socket running from top to bottom through the workhead, near one end. A thin metal handle extends downwardly from the workhead near the end opposite its wire nut socket end. To form a pigtail splice in a wire nut with the wrench, the wire nut is fitted into the socket in the workhead, and the bare ends of a pair of conductors are then inserted as far as they will go into the wire nut. These conductors are next held tightly with one hand near the wire nut, and the workhead is spun rapidly around the axis of the wire nut socket, by means of the wrench handle, with the other hand. This action twists the wire ends into a pigtail splice and tightens the wire nut firmly in place around the splice.
10 Claims, 6 Drawing Figures 1 WIRE NUT WRENCH BACKGROUND OF THE INVENTION This invention relates generally to means for quickly and easily forming pigtail splices between electrical conductors, and more particularly to a wrench of unique design for use in the rapid installation of wire nuts on the bare ends of the conductors for the formation of such pigtail splices.
In the course of their daily work, electricians have occasion to make thousands of splices between conductor wires. Many of these splices are of the so-called pigtail variety. Typically, a pigtail splice is made by manually twisting a wire nut onto the bare ends of a pair of conductors. As any electrician is aware, a wire nut is a type of screw-on wire connector comprising a generally elongate shell, typically made of plastic, enclosed at one end and having a longitudinal hollow which is divided into two sections by an annular ring or shoulder. The innermost of these sections has a frustoconical wall, converging toward the enclosed end of the wire nut hollow, sized to snugly receive, at its larger end, the stripped ends of two conductors, and fitted with a threaded insert. The outermost of the two sections of the hollow has either a generally cylindrical or flaring wall, and is of large enough cross section to easily accommodate the insulated conductors, so that the bare or stripped ends of these conductors can be inserted into the wire nut far enough for a portion of the wire nut shell to surround the wires adjacent their stripped ends to afford insulation against accidental touching of the bare wire ends, or contact of the latter with metal, or other conductive material, in the vicinity.
Typically, the wire nut shell 'is of nonconductive plastic construction (although it can be formed from any other suitable nonconductive material), and its threaded insert is made of metal. As those skilled in the electrical arts are aware, a wire nut is ordinarily employed by hand screwing it tightly onto the bare ends of a pair of conductor wires until the threads of the wire nut insert bite into the wire ends and sqeeze them together for good electrical contact. Some twisting of the wires is also accomplished by this procedure, which makes for enhanced contact therebetween. Wire nuts are available-in several sizes and shapes, but each is characterized by a pair of diametrically outstanding fins to permit better hand purchase of the nut while it is being tightened onto a pair of conductors.
The conventional method of installing wire nuts described above is slow, tedious, and difficult to perform, and often hard on the fingers. Even an experienced electrician, especially when he is on a big construction job where a tight schedule must be followed, can end up with sore fingers after installing a few wire nuts in this fashion. It is unwise to attempt to eliminate this problem through the use of pliers on the nuts, since this practice can result in cracking of the plastic wire nut shell and a consequent risk of short circuits.
Wire nuts have been in common usage for some time, and, once installed, they serve their purpose well. In spite of their long period of use and acceptability in a vitally important segment of the building industry, however, no one heretofore, to my knowledge, has provided means for alleviating the present difficulties of installing these extremely useful items of hardware. Consequently, wire nuts are still laboriously installed by hand, in spite of the work speed-up, greater ease of installation, and other, advantages which would accrue from'the use of more efficient means to accomplish the same end.
'SUMMARY OF THE INVENTION The wire nut wrench of this invention is a simple and inexpensive hand tool designed to firmly hold a wire nut in position while it is being tightened onto the bare ends of a pair of conductor wires to splice the wires together. Becauseof an inherent mechanical advantage, the tool permits the wire nut tightening procedure to be 'accomplished with great ease and rapidity. In its preferred form, the wire nut wrench consists of a somewhat elongate, relatively narrow, block-like body (generally referred to hereinafter as a workhead) of molded plastic construction, having a socket running from top to bottom therethrough, near one end, and a relatively thin handle secured to the workhead so as to depend from the underside of that body near its other end. The handle is long enough to be easily grasped by hand, and is disposed in parallel relationship to the axis of the socket. The workhead is fixed at such length that the separation between the socket and handle axes yields adequate leverage to permit relatively easy turning, or spinning, of the workhead around the axis of the socket, by a cranking motion of the handle, during usage of the tool.
The socket in the workhead of the wire nut wrench has diametrically opposite grooves in its defining wall and is shaped to receive and hold any of a plurality of wire nuts of various shapes and sizes against rotational movement relative to the workhead, when the latter is turned, or spun, by means of the wrench handle. The wrench is easily employed to tighten a wire nut on the bared ends of a pair of conductors by first fitting the nut into the socket in its workhead; inserting the ends of the conductor wires into the hollow in the wire nut as far as they will go; then, while holding the insulated wires tightly near their stripped ends with one hand,
rapidly spinning said workhead around the axis of said socket, by means of said handle, with the other hand. The spinning is continued until the threads of the threaded insert in the wire nut bite into the bared wire ends and twist them into close enough contact for good electrical connection. This can be quickly and easily accomplished by a skilled electrician with a few deft turns of the wrench handle, as opposed to the slow, tedious, and tiring way of installing wire nuts by the presently conventional installation procedure.
It is thus a principal object of this invention to provide simple hand tool means for the quick and easy preparation of pigtail wire splices in wire nuts.
It is a second object of the invention to provide such means of compact and inexpensive construction.
It is another object of the invention to provide such means usable for long periods of time with substantially no pain or discomfort to the user.
Other objects, features and advantages of the invention will become apparent in the light of subsequent disclosures herein.
BRIEF DESCRIPTION OF THE DRAWING tails being shown in dotted lines, for better illustrative effect; and showing, additionally, a wire nut and fragmentary segments of a pair of conductors with their ends bared for splicing, the wire nut and conductor segments being depicted in positions of approaching proximity to the wire nut wrench to illustrate the manner of usage of the wrench.
FIG. 2 is a bottom view of the FIG. 1 wire nut wrench, certain hidden features of the wrench being shown in dotted lines.
FIG. 3 is a top view of the wire nut wrench.
FIG. 4 is a fragmentary view, mostly in section, showing the main parts of the FIG. 1 wire nut wrench.
FIG. 5 is a side elevation of a wire nut of different shape from the FIG. 1 wire nut.
FIG. 6 is a side elevation of another wire nut of different shape from that shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT Considering now the drawing in greater detail, there is shown generally at 10 a preferred embodiment of a wire nut wrench in accordance with this invention. Wire nut wrench 10 has a relatively narrow, somewhat elongate workhead l2, and a thin, sturdy handle 14. The workhead 12 is of generally block-like form, and molded plexiglass construction, although it could, if desired, be made of any other plastic material having sufficient strength and toughness for the purpose. The workhead of my novel wire nut wrench need not necessarily be made of plastic, in fact, but can be formulated from any other suitable material, such as, for example, a metal (preferably a lightweight metal), within the scope of my invention.
Handle 14 is formed from an elongate bolt 15 and a metallic sleeve 22. Sleeve 22 fits loosely around the bolt for a good portion of its shaft length, as illustrated in FIG. 1. Bolt 15 has a head 18 at one end and is threaded for a relatively short distance from the other end, the threads being shown at 20 in FIG. 4. There is a tapped opening 21 running from top to bottom through workhead 12, near one end, adapted to matingly receive the threaded end of bolt 15 to permit the attachment of handle 14 to the workhead. This attachment is accomplished with the aid of a nut 24, which is screwed down onto the threaded end of bolt 15 as far as it will go, after the metallic sleeve 22 has been slipped down onto said bolt. The sleeve is long enough to occupy most of the space between the head 18 of the bolt and the tightened nut 24. The sleeve fits loosely on bolt 15 to permit the turning of handle 14 with minimal difficulty during usage of the wire nut wrench in the below-described manner.
After sleeve 22 and nut 24 are positioned on bolt 15 as described above, the bolt is screwed tightly onto the tapped opening 21 in workhead 12 as the final step in the installation-of handle 14. Nut 24 serves as a stop for workhead 12 to make it possible to obtain a good tight fit between the workhead and wrench handle. For obvious reasons, the threaded parts of the wrench are designed to cooperate in such a way that handle 14 is inherently self-tightening when the wrench is in service. The component parts of handle 14 can be made of any tough, durable metal or alloy, such as, for example, stainless steel. The handle is not limited to such a material of construction, however, and can be fashioned from any material, or materials, metallic or otherwise, having suitable properties for the purpose.
There is a socket 16 in workhead l2, shaped to receive a wire nut and hold it locked in position against rotational movement, relative to the workhead, while wrench 10 is in use. Wire nuts, as previously indicated, come in various shapes and sizes, but all are characterized by the presence of the pair of diametrically outstanding vanes referred to earlier, which serve to make the wire nuts easier to install manually. A common type of wire nut is shown at 36 in FIG. 1. Wire nut 36 has a pair of outstanding vanes 37 with enlarged outer end segments 39 which merge into smaller segments 41 having outer edges convergent in the direction of the enclosed end of the wire nut. FIGS. 5 and 6 show two other types of wire nuts, at 38 and 40, respectively, with vanes noticeably different in appearance from those of wire nut 36.
To permit socket 16 in workhead 12 to receive any of a variety of wire nuts, as exemplified by wire nuts 36, 38 and 40, the defining wall of the socket is divided into a generally cylindrical upper segment 26, with diametrically opposite slots 34 extending radially outwardly therefrom; and a lower, frusto-conical segment 28 with a wall indented by a pair of relatively shallow slots 44 extending downwardly from slots 34 and having bottoms which converge toward the axis of the socket as they approach its lower end. The lower segment 28 terminates at an annular, inturned lip or flange 30 which defines a constrictive opening 32 in the bottom of socket 16. The lip or flange 30 has a pair of diametrically opposite notches or indentations 46 positioned in alignment with the slots 44, as best seen in FIGS. 2 and 3, for a purpose hereinafter made clear.
As previously indicated, wire nut wrench 10 is employed as a tool for the quick and easy twisting of a wire nut onto the bared ends of a pair of conductors to splice the conductors together. This twisting is accomplished by first inserting the bared ends of the conductors into the receptive hollow in the wire nut as far as they will go, in the direction and manner made clear in FIG. 1 which shows such a pair of conductors 48 in approaching proximity to the hollow opening in wire nut 36. The internal configurations of wire nuts such as those described above, and illustrated in the drawing, are well known to those skilled in the art, hence are not illustrated herein. Suffice it to say that each of the wire nuts has an inner segment containing a threaded insert, that portion of wire nut 36 containing the insert being pin-pointed by the numeral 42 in the drawing.
After the bared ends of the conductors have been inserted into theaforesaid wire nut, the latter is, in turn, inserted into socket 16 of the workhead 12. FIG. 1 shows the wire nut 36 aligned for proper insertion into socket 16, it being noted that vane segments 44 and 39 of vanes 37 are respectively aligned with slots 44 and 34 in that socket, to permit mating interfit between the wire nut and socket. After the wire nut has been fitted into socket 16, the conductor wires (38) are firmly grasped near the wire nut (where they are, of course, insulated) with one hand, and handle 14 is grasped with the other hand and turned so as to cause the rapid rotation of workhead 12 around the axis of socket 16. A few quick turns of the wrench, in this fashion, causes the wire nut to twist itself onto the bared ends of the conductor wires, after which the wires .are retained firmly in the wire nut by the biting threads of its workhead 12 when the tool is being turned as de-- scribed.
It will be evident that wires can be spliced in a wire nut similar to wire nut 38 or 40 by a procedure such as that described above for the splicing of wires in wire nut 36. Thus, the bare wire ends are inserted into the wire nut of either of these types, and the latter is then fitted into socket 16 so that its vanes are accomodated by appropriate slots in the socket wall. Workhead 12 is then spun around the axis of socket 16, by means of handle 14, until the wire nut is twisted onto the wires. It will be apparent from the teachings herein, and the accompanying drawing, that wire nuts of differing sizes, as well as shapes, can be made to fit into socket 115 to permit use of wrench for the forming of wire splices in the above-described manner.
While my novel wire nut wrench has been herein described and illustrated in what I consider to be a preferred embodiment, it will be appreciated by those skilled in the art that my invention is not limited to that particular embodiment, but is broad enough in concept to encompass all modifications thereof incorporative of the structural and functional essence of the invention as taught herein. Certain of these modifications have already been mentioned, and others will occur to those skilled in the art in the light of present teachings. Exemplary of the latter are noncritical variations of the shapes, sizes and relative positions of parts or features of the illustrated wrench; the elimination of certain features of the tool not critically essential to its proper use and functioning; the inclusion of nonillustrated features of a useful character, not essential to proper use and functioning of the tool, in its design; etc. More specific examples of such modifications include wrenches with corresponding slots in their wire nut socket walls offset 90 from slots 34 and 44 in socket 16 of wrench 10; wrenches having no sleeves corresponding to sleeve 22 on their handles; wrenches with permanently attached, rather than removable, handles; etc.
Finally, while I have herein stressed the pigtail splicing utility of my novel wrench, it will be understood that the wrench is not necessarily limited to that particular field of use, and can be employed in any capacity to which its unique capability suits it. It is emphasized, in final summary, that the scope of the present invention extends to all variant forms thereof encompased by the language of the following claims.
l. Wrench means particularly suitable for the twisting of wire nuts onto the ends of electrical conductors to form pigtail splices therebetween, said wrench means comprising, in its operative form: workhead means with structure defining a socket adapted to receive a wire nut and hold it in nonrotatable relationship with respect to said workhead means; and elongate handle means fixedly secured to said workhead means, in spaced apart and axially parallel relationship with said socket, so as to extend from the workhead means in the opposite direction to that in which the receptive opening of said socket faces; said workhead means and said handle means being designed and relatively positioned to cooperate in a way to permit the formation of a pigtail splice between the bare ends of a pair of said electrical conductors in a wire nut when said bar ends are firmly inserted into said wire nut, the wire nut is fitted into said socket in said workhead means, the conductors are held tightly near said wire nut with one hand and said handle means is turned with the other hand so as to cause rotation of said workhead means around the axis of said socket with the wire nut and bare conductor ends positioned therein.
2. Wrench means in accordance with claim 1 in which the structure defining said socket also defines diametrically opposite grooves in the socket wall adapted to receive diametrically opposite vanes of the type found on conventional wire nuts to prevent the relative rotation of such a wire nut with respect to said workhead means when the wire nut is fitted into said socket.
3. Wrench means in accordance with claim 2 in which said workhead means is of molded plastic construction, said plastic being any plastic material of sufficient strength and toughness to permit said socket to hold said wire nut in nonrotatable relationship with respect to said workhead means when said bar conductor ends are being formed into a pigtail splice in the wire nut, and said handle means is made of a metallic material of sufficient toughness and durability to permit it to be turned with enough force so that said pigtail splice is formed between said conductor ends in said wire nut seated in said socket during this turning operation.
4. Wrench means in accordance with claim 3 in which the walls defining said socket and said diametrically opposite grooves are designed to receive any of a plurality of differently sized and shaped wire nuts.
5. Wrench means in accordance with claim 4 in which said handle means comprises an elongate bolt having a loose fitting cylindrical sleeve disposed around its shank to facilitate the turning of said handle means when said wrench means is in use.
6. Wrench means in accordance with claim 5 in which said elongate bolt is threaded at one end and is fixedly secured to said workhead means by threaded engagement with a tapped bore in the latter.
7. Wrench means in accordance with claim 6 in which said workhead means is of plexiglass construction, and the parts of said handle means are made of stainless steel.
8. Wrench means in accordance with claim 7 in which said handle means includes a nut screwed onto the threaded end of said bolt to provide tightening means to aid in a firm connection between said workhead means and said handle means.
9. Wrench means in accordance with claim 8 in which the threads of said bolt, said nut and said tapped bore in said workhead means run in the proper direction to have a tightening effect on said handle means when said wrench means is in use.
10. Wrench means in accordance with claim 9 in which said socket runs from top to bottom through said workhead means.