CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Chinese Patent Application No. 201310168312.9 filed on May 6, 2013 in the State Intellectual Property Office of China, the whole disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a method to simply and quickly mount a cold shrinkable termination on a joint end of an electric cable, and relates to a cold shrinkable termination assembly capable of simply and quickly mounting the cold shrinkable termination on the joint end of the electric cable.

Description of the Related Art

In prior arts, a process of mounting a cold shrinkable termination on a joint end of an electric cable generally comprises steps of: removing a section of conductive shield layer from the joint end of the electric cable to expose an inner insulation layer, and removing a section of the exposed inner insulation layer to expose a conductive core; coating a layer of grease on the exposed inner insulation layer of the joint end of the electric cable; and mounting the cold shrinkable termination on the joint end of the electric cable on which the layer of grease has been coated. As a result, the grease is filled in a gap between the cold shrinkable termination and the joint end of the electric cable to prevent a local discharge and an electrical breakdown on the joint end of the electric cable.

However, in some cases, for example, in a tunnel, at high altitude, etc., it may be difficult or impossible to perform an operation of coating the grease on the joint end of the electric cable in field. As a result, an operator may take a great deal of time and effort to perform the coating operation in the field, furthermore, the coating effect may be very poor. SUMMARY OF THE INVENTION

The present invention has been made to overcome or alleviate at least one aspect of the above mentioned disadvantages.

Accordingly, it is an object of the present invention to provide a method to simply and quickly mount a cold shrinkable termination on a joint end of an electric cable.

Accordingly, it is another object of the present invention to provide a cold shrinkable termination assembly capable of simply and quickly mounting the cold shrinkable termination on the joint end of the electric cable.

According to an aspect of the present invention, there is provided a method of mounting a cold shrinkable termination on an electric cable, comprising steps of:

S 100: providing a support tube on a section of an outer wall on which a layer of paste is coated;

S200: pre-expanding an insulation body of the cold shrinkable termination on the support tube on which the layer of paste has been coated;

S300: inserting a joint end of the electric cable, from which a section of conductive shield layer and a section of inner insulation layer have been removed, into the support tube; and

S400: dismantling the support tube from the joint end of the electric cable, so that the cold shrinkable termination is contracted on the joint end of the electric cable and that the paste is filled in a gap between the cold shrinkable termination and the joint end of the electric cable to prevent a local discharge on the joint end of the electric cable.

In an exemplary embodiment of the present invention, the paste has a cone penetration of 130-205 per 0.1mm at a temperature of 25 ^° C , and the paste is 4# grease or 5# grease.

In another exemplary embodiment of the present invention, the paste has no swelling effect on the insulation body of the cold shrinkable termination and the inner insulation layer of the electric cable.

In another exemplary embodiment of the present invention, the inner insulation layer of the electric cable is made of rubber or crosslinked polyethylene.

In another exemplary embodiment of the present invention, the paste is silicone grease, fluorine silicone grease or phenyl silicone grease.

In another exemplary embodiment of the present invention, between the step S300 and the step S400, further comprising a step of:

S310: providing a metal termination, inserting one end of the metal termination into the support tube from an end of the support tube opposite to the electric cable, and electrically connecting the one end of the metal termination to an exposed conductive core of the electric cable.

In another exemplary embodiment of the present invention, the metal termination is crimped to the exposed conductive core of the electric cable.

In another exemplary embodiment of the present invention, the metal termination is sealed to the insulation body of the cold shrinkable termination.

In another exemplary embodiment of the present invention, the cold shrinkable termination comprises a stress control tube provided in the insulation body.

In another exemplary embodiment of the present invention, the stress control tube and the insulation body are formed into one piece.

According to another aspect of the present invention, there is provided a cold shrinkable termination assembly, comprising: a support tube on a section of an outer wall of which a layer of paste is coated; and a cold shrinkable termination having an insulation body pre-expanded on the support tube on which the layer of paste has been coated.

According to another aspect of the present invention, there is provided a method of mounting a cold shrinkable termination on an electric cable, comprising steps of:

providing a cold shrinkable termination assembly according to the above embodiment; inserting a joint end of the electric cable, from which a section of conductive shield layer and a section of inner insulation layer have been removed, into the support tube; and dismantling the support tube from the joint end of the electric cable, so that the cold shrinkable termination is contracted on the joint end of the electric cable and that the paste is filled in a gap between the cold shrinkable termination and the joint end of the electric cable to prevent a local discharge on the joint end of the electric cable.

In the above various embodiments of the present invention, the layer of paste is pre-coated on the support tube in factory, and the cold shrinkable termination is

pre-expanded on the support tube, on which the paste has been coated, in factory. Thereby, the cold shrinkable termination can be quickly mounted on the joint end of the electric cable in field by simply inserting the joint end of the electric cable into the support tube and dismantling the support tube in the field. In this way, the present invention avoids the need of coating the paste on the joint end of the electric cable in the field, improving the efficiency and quality of mounting the cold shrinkable termination in the field.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings, in which:

Fig. l is an illustrative view of a cold shrinkable termination to be mounted on a joint end of an electric cable according to an exemplary embodiment of the present invention;

Fig.2 is an illustrative view of a support tube on which a layer of paste is pre-coated according to an exemplary embodiment of the present invention;

Fig.3 is an illustrative view of pre-expanding the cold shrinkable termination of Fig. l on the support tube of Fig.2, on which the layer of paste has been pre-coated, according to an exemplary embodiment of the present invention; and

Fig.4 is an illustrative view of the cold shrinkable termination mounted on the joint end of the electric cable by means of the support tube of Fig.3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE

IVENTION Exemplary embodiments of the present disclosure will be described hereinafter in detail with reference to the attached drawings, wherein the like reference numerals refer to the like elements. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein; rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the concept of the disclosure to those skilled in the art.

Fig.1 is an illustrative view of a cold shrinkable termination 100 to be mounted on a joint end of an electric cable according to an exemplary embodiment of the present invention.

As shown in Fig. l, the cold shrinkable termination 100 mainly comprises a cylindrical insulation body 110. A stress control tube 120 is provided in the insulation body 110 to prevent a local electric field concentration and a local discharge breakdown on the joint end of the electric cable.

In an exemplary embodiment of the present invention, the stress control tube 120 and the insulation body 110 may be formed into one piece.

As shown in Fig. l, a plurality of conical projections 111 are formed on an outer wall of the insulation body 110 to increase the creepage distance of the cold shrinkable termination 100.

Fig.2 is an illustrative view of a support tube 400 on which a layer of paste 300 is pre-coated according to an exemplary embodiment of the present invention.

As shown in Fig.2, the layer of paste 300 is pre-coated on a section of an outer wall of the support tube 400 corresponding to the joint end of the electric cable (see Fig.4) in factory. The layer of paste 300 is uniformly coated on the outer wall of the support tube 400. The coating amount of the layer of paste 300 may be varied according to the size of the joint end of the electric cable, for example, may be in a range of 3-30 grams.

Fig.3 is an illustrative view of pre-expanding the cold shrinkable termination 100 of Fig. l on the support tube 400 of Fig.2, on which the layer of paste 300 has been pre-coated, according to an exemplary embodiment of the present invention.

As shown in Fig.3, the cold shrinkable termination 100 of Fig. l may be pre-expanded on the support tube 400 of Fig.2, on which the layer of paste 300 has been pre-coated, in factory, so as to obtain a cold shrinkable termination assembly comprising the cold shrinkable termination 100 and the support tube 400. Thereby, the cold shrinkable termination 100 can be quickly mounted on the joint end of the electric cable in field by simply inserting the joint end of the electric cable into the support tube 400 and dismantling the support tube 400 in the field. In this way, the present invention avoids the need of coating the paste 300 on the joint end of the electric cable in the field, improving the efficiency and quality of mounting the cold shrinkable termination 100 in the field.

Fig.4 is an illustrative view of the cold shrinkable termination 100 mounted on the joint end of the electric cable 200 by means of the support tube 400 of Fig.3. As shown in Fig.4, after inserting the joint end of the electric cable 200 into the support tube 400 of the cold shrinkable termination assembly of Fig.3 and dismantling the support tube 400 from the joint end of the electric cable 200, the cold shrinkable termination 100 is simply and quickly mounted on the joint end of the electric cable 200.

In an exemplary embodiment of the present invention, the paste 300 has enough flowability so that the paste 300 can be smoothly filled in the gap between the cold shrinkable termination 100 and the joint end of the electric cable 200. In an exemplary embodiment, the paste 300 has a cone penetration of 130-205 per 0.1mm at a temperature of 25 ^° C . In an exemplary embodiment, the paste 300 may be 4# grease or 5# grease.

In an exemplary embodiment of the present invention, the paste 300 has no or low swelling effect on the insulation body 1 10 of the cold shrinkable termination 100 and/or the inner insulation layer 220 of the electric cable 200. In an exemplary embodiment, the paste 300 may be silicone grease, fluorine silicone grease or phenyl silicone grease.

In an exemplary embodiment of the present invention, the inner insulation layer 220 of the electric cable 200 may be made of rubber or crosslinked polyethylene.

As shown in Fig.4, in an exemplary embodiment of the present invention, the cold shrinkable termination 100 may further comprise a metal termination 500. Before dismantling the support tube 400 from the joint end of the electric cable 200, one end of the metal termination 500 is inserted into the support tube 400 from an end of the support tube 400 opposite to the electric cable 200, and is electrically connected to an exposed

conductive core 210 of the electric cable 200. In an exemplary embodiment, the metal termination 500 may be crimped and electrically connected to the exposed conductive core 210 of the electric cable 200.

As shown in Fig.4, the metal termination 500 is sealed to the insulation body 1 10 of the cold shrinkable termination 100. In an exemplary embodiment, a layer of seal paste 600 is pre-placed on the inner wall of the end (right end in Fig.4) of the insulation body 1 10 before the metal termination 500 is inserted into the insulation body 1 10. As a result, after the metal termination 500 is inserted into the insulation body 1 10, the seal paste 600 can seal the fitting interface between the metal termination 500 and the insulation body 1 10. In an exemplary embodiment, the seal paste 600 may be pre-pressed on the inner wall of the insulation body 1 10 by means of the support tube 400 or pre-filled or pre-coated on the inner wall of the insulation body 1 10.

Although it is not shown, before inserting the joint end of the electric cable 200 into the support tube 400, a section of conductive shield layer 230 is removed from the joint end of the electric cable 200 to expose an inner insulation layer 220 there underneath, and an end section of the exposed inner insulation layer 220 is removed to expose the conductive core 210 there underneath.

Hereafter, it will describe in detail the method of mounting a cold shrinkable termination on an electric cable with reference to Figs.1-4. The method may comprise steps of:

S I 00: providing a support tube 400 on a section of an outer wall of which a layer of paste 300 is coated, as shown in Fig.2;

S200: pre-expanding an insulation body 1 10 of the cold shrinkable termination 100 on the support tube 400 on which the layer of paste 300 has been coated, as shown in Fig.3 ;

S300: inserting a joint end of the electric cable 200, from which a section of conductive shield layer 230 and a section of inner insulation layer 220 have been removed, into the support tube 400; and

S400: dismantling the support tube 400 from the joint end of the electric cable 200, so that the cold shrinkable termination 100 is contracted on the joint end of the electric cable 200 and the paste 300 is filled in a gap between the cold shrinkable termination 100 and the joint end of the electric cable 200 to prevent a local discharge on the joint end of the electric cable 200, as shown in Fig.4.

When the cold shrinkable termination 100 comprises the metal termination 500, the above method may further comprise a step of:

S310: before dismantling the support tube 400 from the joint end of the electric cable 200, providing a metal termination 500, inserting one end of the metal termination 500 into the support tube 400 from an end of the support tube 400 opposite to the electric cable 200, and electrically connecting the one end of the metal termination 500 to an exposed conductive core 210 of the electric cable 200.

According to another concept of the present invention, there is provided a method of mounting a cold shrinkable termination on an electric cable, comprising steps of:

providing a cold shrinkable termination assembly as shown in Fig.3;

inserting a joint end of the electric cable 200, from which a section of conductive shield layer 230 and a section of inner insulation layer 220 have been removed, into the support tube 400; and

dismantling the support tube 400 from the joint end of the electric cable 200, so that the cold shrinkable termination 100 is contracted on the joint end of the electric cable 200 and the paste 300 is filled in a gap between the cold shrinkable termination 100 and the joint end of the electric cable 200 to prevent a local discharge on the joint end of the electric cable 200.

It should be appreciated for those skilled in this art that the above embodiments are intended to be illustrated, and not restrictive. For example, many modifications may be made to the above embodiments by those skilled in this art, and various features described in different embodiments may be freely combined with each other without conflicting in configuration or principle.

Although several exemplary embodiments have been shown and described, it would be appreciated by those skilled in the art that various changes or modifications may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

As used herein, an element recited in the singular and proceeded with the word "a" or "an" should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to "one embodiment" of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments "comprising" or "having" an element or a plurality of elements having a particular property may include additional such elements not having that property.