CABLE TERMINAL WITH BODY AND SLEEVE MARKER WITH RECESS FREELY ROTATING WITH RESPECT TO THE METAL PLUG

Abstract: This Patent covers an electric cable terminal with body (3) and transparent recess for marking elements (7), freely rotating with respect to the metal tip (plug) (1). The body (3), provided with recess for the marking elements (7) is in soft, flexible and transparent plastic for easy removal of the body from the metal end of the tip (plug) incorporated in the body by injection molding, the recess housing the marking el­ ements (7) can be freely rotated to facilitate assembly of the marking elements in a boring (8) of the recess (7) so that the codes are easily readable. A large welt (2) at the end of the metal tip (plug) (1) incorporated in the body (3), prevents axial sliding between the body and the tip (plug).

Description: This invention covers an electric cable terminal with recess for marking elements rotating with respect to the metal tip (plug). Terminals for electric cables, used to connect cables to the machines, equipment and electric instruments are well known. They are substantially consisting of an insulating body, usually in plastic material, partially surrounding the insulated end of the cable and a metal tip (plug) receiving the bare conductor, in which this tip acts as a plug penetrating inside a fixed bush of the equipment receiving or transmitting electric current or signals. The terminal assembly is generally obtained by injection molding of the plastic body on the metal plug. As marking of cable, was developed for their better identification during installation, maintenance and inspection, cables are either directly marked or their terminal is provided with a sleeve marker. Several tecniques are known for wire marking, while several techniques are also known for marking of terminals and specific reference is made hereinafter to the latter techniques. It is well known that the French Patent n° 1.468.859 for cable marking, is consisting of a terminal having in its body an extension or bar on which the marking rings are mounted; this extension is provided at one end with a tooth to prevent the marker elements from slipping off. This known terminal has two main drawbacks. The first drawback is that the marking element is not protetcted, it easily becomes dirty and may become illegible after some time. The second drawback is due to the fact that the marking element cannot be rotated with respect to the cable, as after assembly of the terminal and its fastening on the cable, the marking can be on one side or even at the bottom of the cable so that it would be impossible to introduce the marking element or read it after connection. The latter drawback is particularly felt for the connection of large-sized and rigid cables and since there is a direct mechanical connection between the plug, body and sleeves of the terminal, the position of the marker bearing sleeve cannot be changed after its installation unless the cable is twisted. Recently a terminal is also known, according to FR-A-2 477 330 and corresponding DE-C-3 107 083, by which the sleeve marker extension or bar is inserted and mounted inside a hole in the terminal body. According to this known solution the terminal can be used with or without marking elements, but when it is used with the marking elements it has the same drawback as the terminal of the already mentioned French Patent n. 1 468 859. When using the marking elements the cost of the terminal will obviously be higher since it is consisting of several separate components which have to be obtained from individual molds. The above mentioned Patents FR-A2 477 330 and DE-C-3 107 083 present the drawback too that the marking elements cannot be rotated in respect to the cable, the plug presents a curved end incorporated in the body, but this curved end is very little and it is not separable from the body by rotation. It is also known from FR-A-1 321 537 a device for marking the terminals which present a marking support presenting longitudinal openings housing the codified labels and a plug having a pincers-shaped element for fixing the cable. The support and the plug are independent, i.e. the plug is not incorporated by moulding in the support and that creates difficulties in the assembling of the terminal on the cable. The aim of this Invention is to present a terminal with a marker extension protecting the marking elements so that they are always legible and so that the marker sleeve can be rotated with respect to the metal plug fixed to the cable, so that by rotating the extension marking may be performed easily, while allowing for markings to be read after connection. This aim is reached by the fact that the terminal presents the following peculiarities: a) the recessed extension (7) presents an internal longitudinal boring (8) housing the marking elements (9), b) the end of the metal plug (1) which is incorporated in the plastic body (3) has a large 180° curved welt (2), preventing axial movements between the plug and the body, c) the body (3) of the terminal and the related recess (7) are in soft, flexible and transparent plastic easily separable from the metal plug (1) allowing freely reciprocal rotation. Incidentally it should be noted that in the known terminals according to the above mentioned Patents, the extension or bar receiving and bearing the marking elements is thin and narrow and must therefore be in hard rigid material to allow for installation of the marking elements while preventing deformation. Consequently the whole terminal body is in hard, rigid material, generally in hard rigid plastic. The body of the known terminals is generally in non transparent plastic, since the marking elements are located outside the supporting extension. It should also be noted that in the known terminals the portion of the metal plug which is incorporated in the plastic is only slightly flaring to ensure connection between the plug body, only if this body is in hard, rigid and strong plastic. The Invention in question is illustrated in its practical implementation in the enclosed drawings in which: Fig. 1 shows the longitudinal axial section of the terminal subject matter of this Invention, Fig. 2 shows a terminal section x-x illustrated in Fig. 1, Fig. 3 shows a terminal section y-y illustrated in Fig. 1, Fig. 4 shows a lateral view of the terminal complete with the marking elements mounted on a cable, Fig. 5 shows a top view of the terminal illustrated in Fig. 4, Fig. 6 shows a view from the right side of the terminal illustrated in Fig. 4. With reference to the above illustrations, 1 refers to the tubular shaped terminal conducting metal plug of the terminal, the ends of this plug being surrounded by the body 3 of the terminal, featuring a large external 180° curved welt 2. The body 3 surrounding the shaped end of the plug features an axial boring 4 through which the conductor 5 and the cable 6 pass and laterally features a recess 7 provided with a longitudinal boring 8, which receives and protects the marker elements 9 forming the marking, which in this case are plastic marker rings, already generally used for cable marking according to the known installation practice. According to this invention, the material forming the body 3 and the marker recess 7 is in soft, elastic and transparent material and in general in soft, flexible and transparent plastic. Consequently the said body, together with the marker recess, obtained by injection molding around the welt at the tip of the plug 1, can be easily separated from the plug by small reciprocal rotation movements, because of its soft and elastic nature, so that the body and the related recess can rotate with respect to the plug fixed to the cable, so as to reach the best position for marking and reading of the marking. The axial slipping of the plug from the body and vice versa is prevented by the wide welt 2 at the end of the plug. The transparency of the material forming the body and the recess enables reading of the marking elements placed in the recess and protected by it. The soft and flexible nature of plastic is ideal to allow the marking elements to be also introduced in the recess and to keep them in place. Figures 4, 5 and 6 indicate the terminal complete with marking elements and mounted on the cable 5, 6. Obviously the point 1 is fixed to the bare conductor 5, while the body with the recess can be rotated according to the arrow F so as to be conveniently positioned with respect to the plug and the cable. For exemplification purposes the above Figures show the marking 136K consisting of single marker rings close to one another inside the recess 7.

Claims: Electric cable terminal consisting of a tubular metal plug (1) having a slightly curved end and a plastic body (3) obtained by injection molding of the body on the curved end of the plug, in which the body features an extension (7) bearing marking elements, characterized in that a) the recessed extension (7) presents an internal longitudinal boring (8) housing the marking elements (9), b) the end of the metal plug (1) which is incorporated in the plastic body (3) has a large 180° curved welt (2), preventing axial movements between the plug and the body, c) the body (3) of the terminal and the related recess (7) are in soft, flexible and transparent plastic easily separable from the metal plug (1) allowing freely reciprocal rotation.

Inventors: PIANA, IVANA, PIANA, SILVANO
Applicants: GRAFOPLAST S.P.A.
Application year: 1987
Main classification: H01R13
IPC codes: H01R13, H01R11