US3405443A - Method of electrically connecting mobile apparatus - Google Patents

Description

1968 o. E. JORE ETAL 3,

METHOD OF ELECTRICALLY CONNECTING MOBILE APPARATUS Filed Dec. 8, 1965 INVENTORS OLAV E. JORE STEVE BUNiSH United States Patent METHOD OF ELECTRICALLY CONNECTING MOBILE APPARATUS Olav E. Jore and Steve Bunish, Marion, Ind., assignors to Anaconda Wire and Cable Company, a corporation of Delaware Filed Dec. 8, 1965, Ser. No. 512,295 4 Claims. (Cl. 29-628) ABSTRACT OF THE DISCLOSURE Electric cables for use on mobile apparatus such as overhead cranes, are not jacketed but are coiled and shipped with binder tapes that are removed after the cables have been installed.

Our invention relates to mobile electrical apparatus such as overhead cranes and particularly to a method for making the electrical connection to such apparatus.

It has been conventional to make electrical connections between a control panel and an overhead crane by cutting the required length of a jacketed control cable, many types of which are standard articles of commerce, connecting the cable conductors to the crane at one end of the cable and to the panel at the other end, and suspending the cable in free loops between the attached ends. Connections made in this manner have been troublesome and eX- pensive because of the short life of the cables. The cables are short-lived due to the continual flexing necessitated by the movement, back and forth, of the crane. We have discovered that the life of the cables is shortened by the presence of the jackets Which apparently confine the conductors in a manner so as to create sharp bends at local points when the cables flex. Free hanging, uncabled, insulated wires cannot be used as a method of solving this problem, however, since they tend to whip against each other and to tangle with a resulting life span that is even shorter than that for jacketed cables.

We have discovered that a much improved multistrand electrical connection can be made to overhead apparatus by a method where the plurality of necessary conductors of indefinite length are insulated and helically cabled together to form a cable of indefinite length. This will conveniently be done in a cable factory with one of a number of known types of cabling apparatus. A binder ribbon is then wound around the cable in an open wind. This can be done most conveniently during the cabling operation by means of a binder head attached to the cabling apparatus. Without applying any cable jacket the cable is taken up in a coil which may be formed on a shipping reel and shipped to the site of the overhead apparatus. One end of the cable is connected to the apparatus, such as a crane, and the other end is connected to a terminal such as a panel that is variably distant from the apparatus, with the cable hanging in at least one free loop between the apparatus and the terminal. The binder ribbon is then removed, leaving the cable with its conductors helically stranded together but unconfined. We have found that connections so formed last a much longer time without trouble than any connection for mobile overhead apparatus heretofore known.

A more thorough understanding of our invention will be gained from a study of the appended drawing.

The figure of the drawing shows a schematic representation of the method steps of our invention.

In the practice of our method a plurality of conductors 11 are insulated as by extruders 12 which apply a plastic or rubber coating to form strands 13. Other means for applying cable insulation, such as taping, are known and can be used in the method of our invention. It is a feature 3,405,443 Patented Oct. 15, 1968 of our invention that it provides a new and superior method for installing multistrand cables to mobile apparatus and although we have illustrated an embodiment where the strands 13 comprise simple insulated conductors, it will be understood that each strand element may be more complex as by having jackets or braids over the insulation or being of coaxial construction possibly with conduit elements for compressed air or water and the like, as well as simple electrical conductors. The strands 13 are taken up on spools 15 in the customary manner and cabled together to form a cable core 14 by means of a strander 16, many known types of which are suitable. Although the core 14 may, within the scope of our invention, include all the strands of the cable, in the illustrated embodiment there is applied a second layer of strands 17. This may be accomplished by means of the strander 16 in a known manner or this second layer may be applied by a second strander 18 to form a cable 19. It should be noted that the strands 17 are preferably cabled with a lay of the reverse direction to the direction of lay of the strands 13 and if there are additional layers of strands, which may be the case for large cables within the scope of our invention, the lay is reversed alternately.

As it leaves the strander 18 the cable 19 is wrapped with an open helical winding 21 of binder ribbon. This may be a narrow plastic tape, or a fibrous or paper band. It must, however, be strong enough and flexible enough to withstand, without breaking, the bending of the cable into coils and the rigors of shipment. The ribbon winding 21 is applied by a winding head 22 which may be an element of the strander 18 or, if no further layers are applied over the core 14, an element of the strander 16. In any event the winding 21 is applied before the cable 19 is wound into a coil 23. Several types of binding head are known that are suitable for the practice of our invention. In some types a package of ribbon is revolved bodily around the cable while the ribbon is payed off, and in others the cable passes through the center of an annular package of ribbon.

The winding of the cable into a coil is done by a take-up 24 onto a reel 26 in a known manner. The binder winding 21 holds the cable round during the coiling operation and keeps the cable configuration firm during the shipment of the coil, unwinding from the coil, and attachment of the cable to an overhead apparatus.

The reel 26 containing the coil 23 is shipped in a conventional manner which may comprise a truck 27 or other conveyance to the site of an overhead crane 28. It is a feature of the crane 28 that it is mobile and moves back and forth on tracks 29. The crane 28 comprises a motor 31 and control mechanisms that are activated by signals carried through the strands 13 of the cable 19 and these are connected at a panel 32 on the crane 28 by connecting one end of the cable 19 to the said panel. The other end of the cable 19 is connected to a terminal 33 which, as the crane moves back and forth is variably distant therefrom. To provide slack to enable the cable to reach the crane at its furthest extension the cable is festooned in a series of vertical, free hanging loops 34 suspended between the crane and the terminal on a plurality of trolleys 36 supported by a rail 37. As the crane moves back and forth the loops 34 are severely flexed. To provide freedom of movement of individual strands in the cable during this flexing the binder winding 21 is removed from the cable after it has been installed. During installation, however, the presence of the binder has assured each strand of the cable having proper length and has prevented the cut cable from unwinding. To prevent the ends of the cable from unwinding or the premature removal of the binder tape, a few turns of hinder or a pair of clamps are tightly applied to the cable ends during installation. In making the connection of the cable 19 to the apparatus 28 the cable may be left on the reel 26 while one end is fastened to the panel 32 and the proper length of cable payed from the reel as the latter is moved to the terminal 33. Alternatively the calculated length of cable may be unreeled from the reel 26, stretched out loosely on the ground, and both ends fastened at the same time. In either event the binder ribbon serves to maintain the integrity of the cable during its installation.

We have invented a new and useful method of connecting a cable to mobile overhead apparatus of which the present description has been exemplary rather than definitive. Other useful embodiments of our invention are included in the methods defined by the following claims.

We claim:

1. A method of making a multistrand connection to a mobile overhead apparatus comprising the steps of:

(a) forming a plurality of insulated conductor strands of indefinite length,

(b) helically cabling said strands together to form a cable of indefinite length,

(c) helically winding a binder ribbon in an open wind around said cable thereby to hold the configuration of said cable during coiling and shipping,

(d) without applying a cable jacket taking up said cable in the form of a coil,

(e) Shipping said coil to the site of said overhead apparatus,

(f) electrically and mechanically connecting one end of said cable to said apparatus,

(g) electrically and mechanically connecting another end of said cable to a terminal variably distant from said apparatus, said cable hanging in at least one free 4 loop between said apparatus and said terminal, and (h) removing said binder ribbon thereby allowing freedom of movement of individual strands in said cable during operation of said apparatus.

2. The method of claim 1 wherein said strands are cabled in a plurality of layers of alternate directions of lay.

3. The method of claim 1 wherein said shipping coil is formed on a cable reel and said coil is shipped on said reel.

4. The method of claim 1 wherein said binder ribbon is applied during said cabling.

References Cited UNITED STATES PATENTS 3,036,146 5/1962 Kamen 17452 1,961,833 6/1934 Staples 576 2,085,082 6/1937 Delaney 13 2,388,018 10/1945 Stover 57-10 2,516,212 7/1950 Hoifmann et al 57-3 2,571,832 10/1951 Chapin 212-21 3,029,586 4/1962 Walsh et al 573 FOREIGN PATENTS 236,615 10/ 1959 Australia.

OTHER REFERENCES Electronics, Sept. 1, 1957, Cable Wrapping Is Easy With Amp Spirap, page 71.

CHARLIE T. MOON, Primary Examiner.

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