It is known in the art to provide electrical connectors for insulated wire and insulated multistranded cable. In some circumstances the connector requires a terminal length of the cable or wire to be stripped of its insulation, while in others the connector can effect a good electrical connection without the stripping of the insulation.
Many connectors, including those provided by the assignee hereof and others, have a component into which a wire or cable end is inserted, typically a bore or other receptacle in a female connector body. Heretofore, the installer has had to guess whether the insulated wire or cable has been inserted into the connector body by the correct depth; it is often the case that the insulated conductor is not inserted into the connector far enough, or is inserted into the connector too far. Either way, and dependent on the particular connector design, the result may be a less than optimum connection in terms of electrical conduction, protection of a stripped end from the environment and physical strain relief.
Similarly there has been heretofore no clear guide, intrinsic to the components themselves, as to how far an end of an insulated conductor should be stripped prior to connection; the installer often has to refer to a separate printed instruction, which might tell him or her to strip off ¼ inch, ½ inch, or some other amount, and other times the installer simply guesses. The resultant variation in stripped lengths causes variability in how good the physical and electrical connections are, and how well the conductor is protected from the environment. If the installer strips the conductor too far, he or she will often have to cut the conductor again and restrip the end, causing waste in materials and time. A need therefore persists for methods and apparatus for cutting, stripping and connecting insulated conductors to connectors and equipment terminals, identically time and time again, so as to minimize installer error.
According to one aspect of the invention, an insulated conductor, of either the solid-wire or multistranded cable type, is provided in kit form with an electrical connector adapted to terminate it. The connector includes a receptacle into which the conductor is inserted. This bore or receptacle defines an optimum length or extent to which the conductor should be inserted into it. The insulation of the conductor has a plurality of cut markings on it, each indicating a place where the user may cut the conductor, and, spaced from respective ones of the cut markings, a plurality of insertion markings. An insertion marking is always spaced from a corresponding cut marking by a predetermined insertion length, chosen as a function of the optimum insertion depth of the connector receptacle. In operation, the user chooses one of the cut markings to cut the conductor to a length suitable for the connection task, and compares the next adjacent insertion marking to a predetermined reference as a guide to determine how far to insert the cut, free end of the conductor into the receptacle.
In one illustrated embodiment, the cut markings are the same as the insertion markings, and are uniformly spaced apart by the predetermined insertion length. In those embodiments in which the connector is of the type which can receive a stripped conductor end, there is further provided a plurality of strip markings, each strip marking spaced from a respective cut marking by a predetermined strip length. It is preferred that the cut markings and the strip markings be distinguishable from each other either visually or by touch.
In a further embodiment, the connector can be of the type which has a separate compression cap which moves relative to a connector body from a first position to a second position, the last position typically forcing the conductor into close contact with the conductive element of the connector. For example, the compression cap may screw on to the connector or may be linearly compressed, without twisting and parallel to the connector axis, from the first position to the second position. Kits according to the invention which have one or more such connectors in them preferably will have a length of insulated conductor which has been manufactured to display initial insertion markings (which preferably are the same as the cut markings) and final insertion markings, each final insertion marking uniformly spaced from a next adjacent initial insertion marking by a cap compression stroke. It is preferred that the initial and final insertion markings be distinguishable from each other by sight or touch. One of the final insertion markings is compared by the user against a predetermined reference (such as an axially outer face of the compression cap) to assure that a firm electrical connection has been obtained.
In certain embodiments, the conductor can have cut markings, initial insertion markings, final insertion markings and strip markings. It is preferred that the cut markings, the final insertion markings and the strip markings be distinguishable from each other by sight or touch.
Some conductor marking schemes permit the conductor to be marked in a uniform marking sequence from one end of the conductor to the other. Other marking schemes disclosed herein require that the conductor have a reflection point which divides the conductor into two parts, with a sequential marking order along the first part being the reverse of a sequential marking order on the second part.
In other forms of the invention, the conductor is furnished with markings as variously described, but not with connectors. Such conductors may be used with predetermined terminals built in to various electrical or electronic equipment or may be used with connectors of a predetermined type. The conductor can be of either the multistranded cable type or the solid core wire type.
The present invention furnishes kits, conductors and methods by which the electrical and physical conditions of termination can be replicated from one particular conductor end to the next, enhancing reliability and uniformity.
Further aspects of the invention and their advantages can be discerned in the following detailed description, in which like characters denote like parts and in which:
An insulation jacket 114 completely surrounds a conductive core of the conductor 106, except for the core's exposed ends. In this embodiment, an elongate, typically flexible cable 106 has a repeating series of three different markings on its insulation jacket 114: cut lines 116A, 116B . . . strip lines 118A, 118B . . . , and final insertion lines 120A, 120B . . . . The placement of these markings on the insulation jacket 114 will be determined by the structure of the connectors 102, 104 which are to terminate conductor 106. It is preferred that the markings 116, 118, 120 be distinguishable by the user from each other—either visually, as is illustrated here, or by touch (see
As will be explained in more detail below, markings 116-120 are at predetermined distances from each other. The distance between a cut line (e.g., 116A) and a next adjacent strip line 118A is always a desired, predetermined strip length, or the length of the end of the conductor from which the insulation 114 is to be stripped. This strip length is preselected to best fit with the particular connector furnished with the kit. After a line 116 is selected for cutting the conductor 106, the user then use the next adjacent strip line 118 as an indicium to determine how far back from the cut end the insulation 114 is to be stripped.
To preserve material it is preferred (but it is not absolutely essential) that the distance between any one cut line (e.g., 116A) and the next adjacent cut line (e.g. 116B) be the same as the length of cable to be inserted into the receptacle of the connector 102, 104. This distance depends on the kind and size of connector furnished with the kit. Here, the distance between cut lines is the same as an initial insertion depth of the cable 106 into one of the connectors 102, 104. The initial insertion depth is composed of all or part of the depth of a bore or receptacle (not shown in this FIGURE) in female connector body 108, plus a distance by which the cap 110 (in a first position thereof) axially extends from an entrance 122 of the bore. In such an embodiment the cut lines 116 have two functions. When a cut line 116x is selected, the next cut line 116x+1 will be used as an initial insertion line: the user lines up the line 116x+1 with an outer end or face 124 of the cap 110 (in its first, uncompressed position, as shown) to assure that the end of conductor 106 has been inserted into the connector 102 far enough. More generally, the user uses initial insertion marking 116x+1 as an indicium which is compared with a convenient reference to determine whether a correct amount of conductor 106 has been inserted into the connector receptacle. This provides a uniform connection and should make the connections so made more reliable in terms of electrical connection, insulation from the environment and strain relief.
The final insertion lines 120 are uniformly separated from respective next adjacent ones of the cut lines 116 (which also act as initial insertion lines) by a distance through which the cap 110 is to move into the bore of the female connector body 108 in completing the connection. When the user has advanced the cap 110 into the connector body bore far enough, such that the cap 110 is correctly and finally assembled to the body 108, the user will see one of the final insertion lines 120. This can be used by the user as a guide to determine whether the cap has been sufficiently advanced to effect a good electrical and physical connection.
In the illustrated kit forms, a user is given at least two connectors and a length of conductor 106 which will be long enough in most circumstances to connect together at least two terminals, electronic components, or the like. The user selects one of the marking sets 116x, 118x, 120x as an end to be connected via connector 102, and another one of the marking sets 116x, 118x, 120x as an end to be connected via connector 104. The user uses one or two of the cut lines 116x to cut the conductor 106 to the desired length. Different marking sets 116x, 118x, 120x are supplied to permit the user to cut conductor 106 to different lengths.
The conductor 106 supplied in the first kit 100 is shown in more detail in
Another kit 200 according to the invention is shown in
The kit 200 includes at least two end connectors 212 and 214, which in this embodiment are identical to each other. Other kits may be provided in which the connectors, and therefore the cable marking sets on opposite ends of the conductor, are intentionally different from each other. Describing connector 212 by way of example, the connector 212 has, as its conductive connector element to further electrical apparatus, a pin connector 216. The connector 216 axially extends in a first direction from a connector body 218 which has a bore 220 therein. A coaxial center pin 222 extends from a floor (not shown) of the bore 220 toward an opening 224 thereof. The connector 212 further includes a collar 226 and a cap 228, through which the conductor 202 is threaded during the process of terminating the conductor 202 with the connector 212.
The connector 212 is of a kind which does not require the insulation 210 to be stripped from an end of the conductor 210 prior to its insertion through components 228 and 226 and into bore 220. The markings on the exterior of the conductor insulation 210 therefore do not include strip lines. In this embodiment, there are cut lines 204B, 204C, . . . , formed by a single circumferential groove; final insertion markings 206A, 206B, . . . , here formed by a double circumferential groove; and initial insertion markings 208A, 208B, . . . , here formed by a single circumferential bump or ridge. These different kinds of touch-perceptible markings are exemplary only.
As before, the distances between different ones of these markings and the markings next adjacent to them are uniform and are predetermined by the dimensions and structure of the connectors 212, 214 provided to terminate the ends of conductor 202. A length 230 between a cut marking 204x and a next adjacent final insertion marking 206x is chosen to be the same as a depth 232 of the bore 220, plus whatever distance the cap 228 extends therebeyond once the cap 228 has begun to be threaded onto the outside threaded cylindrical surface 234 of the connector body 218. A length 240 between any final insertion marking 206x and a next adjacent initial insertion marking 208x may be chosen as equal to the depth of bore 220 plus the length of the cap 228 where it is fitted to the end of the connector body 218 but not yet threaded onto same. This mark would be used by the user to make sure that the conductor 202 is fully impaled on the center pin 222 prior to threading on the cap.
The conductor 202 is illustrated in more detail in
In an alternative embodiment, the cut lines 204x would be merged with the initial insertion markings 208x−1. For example, cut line 204C would take the place of and be in the same position as initial insertion marking 208B, and there would be no length of conductor between these two locations. This embodiment would reduce the number of different markings which needed to be used and would provide a more precise fitting of the cut conductor length to the length needed by the application in question. In a further modification that would permit conductor 202 to be marked left-to-right without any point of reflection 250, the cut markings 204 would also serve as the initial insertion markings 208, and each cut marking 204 would be equidistantly flanked by a pair of final insertion markings 206, only one of which would be used in terminating the conductor.
A cut line 304A has been selected by the user as the place to cut the conductor 300. The conductor 300 has then been inserted through a bore of the cap 310 and into the bore 318 of the connector body 318, until it is impaled and spread on an axial, conically shaped conductive element 320. The user knows that the end of the connector 300 has been fully inserted into bore 318 and impaled onto cone 320 by checking that the initial insertion line 304B lines up with an axially outer surface 322 of the cap 310.
In
The connector 302 shown in
In
In
In this embodiment, the distance between any cut/initial insertion line 414x and a next adjacent cut/initial insertion line 414x+1 is predetermined to be the same as the sum of the length of the conductor 402 to be inserted into the bore 409, plus the distance by which the cap 406 extends axially outwardly from the entrance of bore 409 when the cap 406 is in the first position. The distance between any cut line 414x and a next adjacent strip line 412x is predetermined by the amount of insulation which should be stripped from the conductor end. The distance between any cut/initial insertion line 414x and the next adjacent final insertion line 416x is determined by the “compression stroke” of the cap 406 between its initial position, as seen in
The connector illustrated in
An insulated conductor 600 shown in
In
In the illustrated embodiments of the invention, the visual indicators indicating places to cut, strip limits and insertion limits are formed by thin circumferential lines or thick bands (either solid or interrupted, and either entirely linear or wavy) which are substantially in a plane that is orthogonal to the conductor axis. These indicia are conveniently applied as by paint or ink to a (typically polymeric) insulation jacket. But this is not the only way these visual indicia can manifest themselves. In alternative embodiments, the conductor jacket can be made in alternating bands of colored polymer. Some of these bands may be rendered transparent so that the user can see the conductive core.
While
In an alternative method diagrammed in
A third method for using the invention is diagrammed in
In summary, different schemes for marking the jackets of insulated conductors have been shown and described. The markings provide convenient indicia for cutting, stripping, initial insertion into a connector, and compression using a cap which articulates (screws on, compresses into) the rest of a connector body. The present invention simplifies or obviates the need for separate measuring devices, printed instructions or the like and promotes terminations of conductors which are physically and electrically uniform one to the next.
While illustrated embodiments of the present invention have been described and illustrated in the appended drawings, the present invention is not limited thereto but only by the scope and spirit of the appended claims.
This application is a continuation in part of copending U.S. patent application Ser. No. 11/420,646 filed 26 May 2006, owned by the assignee hereof, and the specification and drawings of which are fully incorporated by reference herein.
Number | Name | Date | Kind |
---|---|---|---|
4288311 | Singleton et al. | Sep 1981 | A |
4763411 | Takeshita | Aug 1988 | A |
5775934 | McCarthy | Jul 1998 | A |
6148130 | Lee et al. | Nov 2000 | A |
6848934 | McCarthy | Feb 2005 | B1 |
Number | Date | Country | |
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20070149033 A1 | Jun 2007 | US |
Number | Date | Country | |
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Parent | 11420646 | May 2006 | US |
Child | 11692856 | US |