Resilient Cover Having A Removable External Support Member

Abstract

This invention pertains to a resilient tubular cover being supported in a stretched condition by an easily removable one piece support member positioned around the outside of the cover. More particularly, the invention resides in a hollow member through which the resilient cover passes and on which the rolled portions of the resilient cover are received and removably retained.

Description

BACKGROUND OF THE INVENTION

The need for an insulated, waterproof cover on electrical cable used in mines and the like led to the present invention. Mine cable, as such electrical cable is called, is subject to considerable amount of abuse in that it is being continuously and routinely passed through pulleys, used on rocky, rough surfaces, tread on by miners and vehicles of various sorts and rolled and unrolled onto and off cable spools or reels. These kinds of abuse cause frequent breaks in the mine cable. Further, it is oftentimes necessary to cut the mine cable to add more to it or to shorten it. The breaks and the intention cuts are repaired by splicing the ends together using a crimpable metal sleeve or other like device and covering the area with a tough insulating and waterproof covering.

In order to achieve a water-tight covering, the cover must fit snugly around the mine cable on either side of the splice. A preferred covering which would meet this requirement is one prepared from a cross-linked polyolefin having heat-responsive dimensional memory and fusion properties such as disclosed in U.S. application Ser. No. 332,479, filed Feb. 14, 1973. However, the application of this kind of material requires heat, generally in the nature of an open flame or heat guns which is prohibited in subsurface mining operations. With this type of limitation workers in the field have developed an elastic cover which is supported in a stretched condition on an easily removable one-piece rigid spiral core. In application this assembly is slipped over one of the cable-ends prior to the joining thereof. After the splice is completed, the assembly is slid into position over the splice area and the core removed by grasping one end thereof and unwinding it, withdrawing the continuous narrow strip from beneath the cover which contracts to its original dimension, such dimension being slightly less than the dimension of the mine cable. Full details of this type of cover are contained in Sievert U.S. Pat. No. 3,515,798 the disclosure of which is incorporated herein by reference. Whereas this cover assembly works well, particularly with respect to insulating the splice area, waterproofing is another matter. Because the linear length of the cover assembly before placing such on a cable is the same as after application, the cable splice area must be pre-coated with a waterproofing coating or a wrapping of adhesive tape which will not stick to the core. Further, the coating or tape must be applied before the cover assembly is slid over the cable splice area. Or alternatively, the inner surface of the cover or elastic tube may carry a thin coating of a pressure-sensitive adhesive; however, the external surface of the supporting spiral core should be coated with a low adhesion backsize composition prior to assembly to prevent the cover from sticking to the core.

Accordingly it is an object of the present invention to provide an assembly utilizing a stretched resilient tubular cover rolled back on itself from both ends and onto a split, annular support member positioned around the outside of the cover's midsection so that as the cover assembly is placed over a cable splice area and unrolled, the cover contracts around the cable to form a closely conforming and tightly retained protective cover and the support member is removed from around the outside of the cover by simply spreading the split sides apart and slipping it off.

Another object of the present invention is to provide a resilient cover assembly where waterproof adhesives may be easily applied to the splice area over which the cover is unrolled.

A further object of this invention is to provide a resilient cover assembly which is easy to use, requires the use of pliers only and which provides insulation and sealing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view, partly in section, showing the preferable embodiment of the present invention;

FIGS. 2 and 3 show the inner and outer support members respectively of the embodiment of FIG. 1;

FIG. 4 shows the detail of the facing sides of the outer support member of FIG. 3;

FIG. 5 illustrates a modified embodiment of the invention of FIG. 1;

FIGS. 6-11 illustrate the assembly of the embodiment of FIG. 1; and

FIGS. 12-17 illustrates the use of the embodiment of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a resilient cover assembly 10 ready for use in insulating and sealing a splice area on mine cable or the like. The assembly consists of a resilient tubular cover member 12, an outer annular support member 14 and an inner sleeve 16. Resilient cover 12 has been longitudinally stretched and while in the stretched condition, rolled back on itself from either end to form two outside rolls 18 and 20.

The stretched and rolled cover member is retained in that condition and shape by rolling rolls 18-20 over annular projections 22 located at either end 24 of outer support member 14.

The inner sleeve 16, also illustrated in FIG. 2, is split lengthwise to receive inbetween the sides removable dividing means which increases the sleeve's diameter. Such dividing means may include an "I-beam" strip 28. The increase in diameter of the sleeve is a function of the width of web portion 30 of the strip. The cross bars 32 of the strip prevent cantilever movement of the sides defined by the split. Inner sleeve 16 and strip 28 may be machined or molded from rigid plastic such as polyvinyl chloride.

Outer support member 14, clearly shown in FIG. 3, is a sleeve-like structure from which in the case of milling, a strip of material of appreciable width has been removed to define a lengthwise clearance 36. In the case of molding the member, the clearance is provided in the mold. The sides 38 of clearance 36 are zagged in mating relation to prevent radial movement when the sleeve is squeezed inwardly under pressure to tubular cover member 12. The zagged sides are shown in an enlarged view in FIG. 4.

The outer surface of support member 14 includes the aforementioned projections 22 at each end 24. The outwardly facing sides 40 of the projections are beveled facilitate rolling rolls 18-20 thereover. The inwardly facing sides 42 are perpendicular to the longitudinal axis of the member to restrain rolls 18-20 from rolling back off.

Adjacent each inwardly facing sides 42 and on the outer surface of the support member are roll-receiving, annular grooves 44. These grooves cooperate with sides 42 to define roll retaining means.

On the inner surface of support member 14 and directly opposite clearance 36 is a shallow inwardly facing groove 48 which extends the length of the member. The groove is the surface representation of reducing the wall thickness of support member 14 at that location to provide a hinge area about which the member opens and closes relative to clearance 36.

In addition to groove 48, the inner surface of support member 14 is serrated or ribbed as indicated at 50. These annular serrations which have a relatively low profile, provide a roughened surface to facilitate assembly of cover member 12 onto support member 14 by reducing the tendency for the cover member to slide.

Tubular cover member 12 is a resilient, elongated sleeve structure which may be molded using butyl rubber or other like insulating material. The inner diameter of the member will be slightly smaller than the diameter of the cable on which the cover member is to be installed.

FIG. 5 shows a modified embodiment 10'. The only change is to outer support member 14, herein designated 14'. The change as can be seen is to one end 24' which is smooth, and to the outer surface wherein only one groove 44' is provided. This groove receives the non-rolled end 52 over which is positioned roll 54, the latter retaining the former with projection 22 retaining the latter.

ASSEMBLY OF THE PREFERRED EMBODIMENT

FIGS. 6 through 11 illustrate the various steps taken and apparatus used in assembling cover member 12, outer support member 14 and inner sleeve 16 into a cover assembly 10 ready for use by a repairman or other workers in those industries likely to use the present invention.

FIG. 6 shows the installing of inner sleeve 16 onto a mandrel 56 consisting of two sections 57-58, the latter having a cone-shaped nose 60 and both having a co-linear air passage 62 therethrough shown by dashed lines. The mandrel may be supported by any conventional holding device, one such being indicated by reference numeral 63. Inner sleeve 16 is placed on sleeve receiving stud 64 on mandrel section 57 after which the two sections are joined via a threaded stud 66 on section 58 and companion threads (not shown) on section 57. Note that the outer diameters of mandrel 56 and inner sleeve 16 are the same (FIG. 7).

After joining the two mandrel sections, a first stretcher subassembly 68, consisting of a sleeve 70 and adjustable clamp 72 is slid onto the assembled mandrel 56. The sleeve has an inner diameter very slightly larger than the outer diameter of the mandrel.

With pressurized air from an air source (not shown) flowing through mandrel passage 62, cover member 12 is worked onto mandrel 56 by shutting off one end of the cover member with one hand and pulling on the other end with the other hand as seen in FIG. 7. This method is necessitated because cover member 12 has a considerably reduced inner diameter relative to inner sleeve 16 and mandrel 56. After a sufficient length of cover member has been worked onto mandrel 56, it is rolled back on itself, subassembly 68 moved into the voided area so that the cover member can be unrolled onto sleeve 70. After the remaining length of cover member 12 has been worked onto the mandrel it too is rolled back on itself, a second stretcher subassembly 68' is slid onto mandrel 56 and the remaining length unrolled onto sleeve 70'.

Cover member 12 is now linearly stretched by first tightening a clamp 72 so as to immobilize the underlying sleeve 70 against mandrel 56 and then sliding the second subassembly 68 away therefrom and stretching cover member 12. Upon stretching the cover member the appropriate length, the second subassembly 68' is immobilized by tightening adjustable claim 72'.

While cover member 12 is in the stretched condition as shown in FIG. 9, the outer support member 14 is placed thereon in overlying registration with inner sleeve 16 and held thereon in an immobile position by means of a plier-like hand tool containing suitable jaw members, such tool being generally designated by reference numeral 74. One end of cover member 12 is rolled back on itself, over projection 22 on support member 14 and into groove 44 to form the aforementioned roll 20 as seen in FIG. 10.

Tool 74 is removed as roll 20 holds support member 14 in a closed position. The other end of cover member 12 is rolled back on itself and onto another end of support member 14 to form roll 18, which also completes the formation of cover assembly 10. The assembly is removed from mandrel 56 by simply unthreading mandrel section 58 and sliding the assembly off stud 64.

UTILITY AND METHOD OF APPLICATION OF THE PRESENT INVENTION

FIGS. 12-17 illustrate the preferable purpose for which the present invention was developed and its method of application.

Two cables 80, comprising stranded conductors 82 and insulating jackets 84, are shwon in FIG. 12, their ends 86 prepared for splicing by removal of a portion of jackets 84. Cover assembly 10 is slipped over one of the cable ends 86 prior to joining the two ends as seen in FIG. 13. The splice may be made using a conventional, crimp-type wire ferrule 88 or the like.

Inner sleeve 16 can be removed before or after cover assembly 10 is slid into position over the spliced area (FIG. 14). This is accomplished by grasping strip 28 with a pair of pliers (not shown) and pulling it out. Sleeve 16 is then squeezed in and freely withdrawn from assembly 10 as shown in FIG. 15. Subsequent to removing sleeve 16, mastic 90 which may be in the form of a coating or pads, is applied to cables 80.

With mastic 90 in place, cover member 12 is unrolled off either end of support member 14 and onto both cables 80 as FIG. 16 shows. As the cover is unrolled it contracts about cables 80 to form a closely conforming and tightly retained protective covering. The mastic forcefully bonds the cover member 12 to cables 80 by the contraction of the cover member as it is unrolled onto the cables. An environmentally insulated, protective cover over the splice area results.

Outer support member 14 is removed from the now single cable 80 by simply spreading and slipping it off. FIG. 17 is a view of the completed covered splice area. As cover member 12 is resilient, flexing of the cable is not impaired thereby.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as some modifications will be obvious to those skilled in the art.

Claims

What is claimed is:

1. A resilient cover assembly useful for covering the spliced area of cables, which comprises, a stretched, elongated, resilient cover member supported by an annular support member, said support member being split longitudinally from end to end, said cover member extending through the support member with the ends of the cover member being rolled up and removably positioned on the outer surface of the support member, said longitudinal split adapted to facilitate removal of the support member from around the cover member after the cover member has been unrolled off the support member.

2. The resilient cover assembly of claim 1 wherein said support member includes annular projections at each end thereof to removably retain said rolled cover member.

3. The resilient cover assembly of claim 1 further including a removable inner sleeve extending through the portion of the rolled cover member which passes through said support member, said sleeve permitting easier installation of the assembly onto one of the cables being spliced together.

4. A method of assembling a resilient cover assembly of the type useful for covering the spliced area of cables, which comprises the steps of:

a. providing a tubular support member;

b. positioning a resilient sleeve-like, cover member through the support member; and

c. rolling up the ends of the cover member toward the center thereof and onto the ends of the support member.

5. A method of assembling a resilient cover assembly of the type useful for covering the spliced area of cables, which comprises the steps of:

a. providing a tubular support member having annular projections at each end thereof;

b. positioning a resilient, sleeve-like cover member through the support member;

c. stretching the cover member axially;

d. rolling up the ends of the stretched cover member toward the center thereof; and

e. positioning the rolled up ends onto the ends of the support member so that said annular projections removably retain them.

6. The method of claim 5 further characterized by the additional step of placing a removable inner sleeve through the portion of the cover member positioned within the support member.