US320229A - Best available cof - Google Patents

Description

UNITED STATES "PATENT OFFICE.

"""'BESTAV ILABLE COPl PATRICK B. DELANY, oF NEW YORK, N. Y.

ELECTRIC CABLE.

SPECIFICATION forming part of Letters Patent No. 320,229, dated .Tune 16, 1885. Application filed December 2,1884. (No model.)

To all whom it may concern:

A Beit known that I, PATRICK B. DELANY, of New York city, New York, have invented an Improved Electric Cable, of which the following is a specification.

My invention relates to that class of cables inl which a lead or other metallic sheath or pipe is formed around the cable. As is Well known, where the lead ingot is heated and then caused to iiow round the ordinary cable under comparatively slight pressure the heat of the pipe is liable to burn the insulation of the wire or wires. It is also true that when a cold ingot is used the great pressure required to form the pipe around the cable not only generates heat at the point offlow, but the friction on the cable is liable to tear,

break, or injure the covering on the wire orY cable, and this liability is increased by the heat generated. For this reason theleadcovered cables of ordinary manufacture are more or less imperfect, and such imperfection -results in a more rapid degeneration of the cable in eontinuedpuse.

The object of the invention is to protect the primary covering on the wire or Wires where insulated wire is used, as well as the insulating compound, which is introduced within the pipe in the immediate neighborhood of the conductors in the process of manufacture, from the heat and destructive friction developed in forming the sheath. 'Io accom plish this endv I employ, in combination with such a sheath or pipe, a series of insulating-buttons, which are strung on the wire or wires, and which not only constitute an insulatingcovering for the wire, but also serve as an armor or shield to protect the wire and the insulation immediately around it during the formation of the sheath.

In Letters Patent of the United States No. 266,353, granted to me October 24, 1882, I have shown a series of abutting, perforated, round-ended, lens-shaped buttons strung on a series of wires. Such buttons may be used under my present invention. In another patent, No. 283,763, grant-ed to me August 28, 1883, I have shown anotherform of button in connection with spacing-block. Obviously,

as presently appears, spacing-blocks may -bewire from the heat of the sheath, for in that casethe block really becomes the equivalent ot the button.

The insulating-buttons employed by me may of course be made of any suitable mat-erial. I prefer, however, to make them of glass, porcelain, `earthenware, or other suitable incombustble insulating material, for the insulation of such a cable would remain intact even if in use a heat internal or external should be generated sufficient to burn off the lead sheath. I also prefer not to use spacingblocks, as above suggested, but-to string the perforated insulating-buttons upon the wire or wires, one against the other, so as to form a continuous button-protection or armor for the conductors. It should be noted, also,

that the particular shape of the insulatingbuttons is immaterial.

In the accompanying drawings, Figure 1 is a sectional view illustrating a portion of a cable having a series of conductors, on which are strung one against the other porcelain insulating-buttons, over which the lead sheath or tube is formed. Fig. 2 is a transverse section of the same. Fig. 3 is a similar view illustrating a cable containing a single conductor, on which perforatedinsul ati n g-b utto ns ofso m ewhat diiierent shape are strung; Fig. 4, a view of another section of cable, showing another form of button; Fig. 5, a similar View of another fornl of cable in which spacing-blocks are used; Fig. 6, a tiansveise section ot' the same; and Fig. 7 shows still another form of button.

In all the views A represent-s a lead or other metallic sheath or pipe which has been form/ed or flowed around the cable according to any of the well-known ways now in general use.

In Figs. 1 and 2 I have shown lens-shaped buttons B, strung one against the other on a series of wires. These wires may have a primary insulation or may be bare. rlhe space within the pipe around and between the buttons and conductors may be iilled with any suitable insulating compound, as illustrated at C in Fig. 4.

In Fig. 3 the buttons B are ol' a somewhat different shape, and are strung upon a single conductor, which passes centrally through the buttons, which conductor may have a primary insulating covering or not, as may be IOL deemed best, and the pi pc may be filled with 'insulating material C, as above mentioned.

It will be perceived that in the cable shown in these tlgures the wire and its primary insulating-covering, as well as that part of the insulating compound which is immediately around the wire in the eyes or perforations of the buttons, will be protected from the heat developed in putting the sheath over the cable, as well as from the damaging frictional contact with the sheath.

In Fig. 4t I have shown buttons having concave depressions on each side and curved peripherics. Under this organization the insulating compound introduced iut-o the pipe will fill the spaces cbctween the opposite coucavefaces of the buttons, but will be thoroughly protected from the heat or friction of the sheath.

In Fig. 5 I have shown buttons similar to those illustrated in Fig. 4; but instead of placing them one against the other I have shown interposed spacing-blocks D. vThese spacingbloclis are formed with radial longitudinal recesses d, within which the conductors are laid. The blocks are preferably of the same diameter as the buttons, and, as will be obvious, the wires will be completely protected. I prefer to employT buttons only, illustrated in the ot-her figures, though so far as theprinciple of the invention is concerned spacing -blocks having recesses of sufficient depth to thoroughly protect the wire constitute buttons.

In Fig. 7 I have shown buttons B, formed on one side with a projecting teat, b, and on the other side with a flat seat, b', against which the teat ofthe adjoining button rests. It will be observed that while the peripheries of such buttons are not in contact or as close together as the peripheries of the other buttons illustrated, still they serve as an etlcctual shield to prevent the sheath from injuringthe insulation of the wires, because they are really so close together that the lead pipe caunot possibly sink or bend down between them to reach the wires. Insulating compound C may also be used in this forni of cable, if desired.

The ordinary lead-pipe machines for form- \ing sheaths around cables are well undersped, and need no illustration or description. So far as the insulating compound is concerned, the cable may be drawn through a bath of it before coming` to the pipe-forining machine, or the compound may be int-roduced within the pipe as it is formed around the cable., or may be forced into the pipe in a liquid condition under pressure afterward. These three operations are, however, conilnon, well known, and generally understood, and therefore need no description nor illustration.

All the forms of cable I have described are capable of bending' or llexing to permit of their ready handlino.

IVhen covered with the lead sheath, the

substantially such as- BESTAVAILABLE coecable may, therefore, be wound upon a reel for transportation, or handled with the rcquired facility.

Another characferistic of my cable is that the buttons, in addition to the functions above described, also serve as armors to resist the bruising, crushing, or mashing of the cable.

A lead sheath is of such softness that an ordinary cable n'iightbc mashed out of shape. In my improved cable, however, the buttons afford a practically continuous support or core for the interior of t-hc cable. The cable is therefore possessed of great strength and durability.

\Vhere several conductors are included in the sheath, the buttons always hold them perfectly separated and at precisely the same distance from each other and from the sheath, no matter how much pressure may be exerted on the buttons, and of course where a single conductor is used, as in Fig. 3, it is always held in the axial line of the tubular sheath. For these reasons, which constitute important features of my invention, my iinproved cable is perfectly uniform in structure.

I am aware that lead coverings have been formed around cables differing in structure from and not possessing the characteristics of my cable. For instance, in the patent of Rogers and Shaw, N o. 220,944, a cable made up of twisted wires, each wire being covered with spun glass or asbestus, is shown as having a lead sheath formed around it by an ordinary lead-pipe machine. I therefore make no claim to such subject-matter.

Iam also aware that the pat-cnt of Manly, No. 231,825, shows conductors passing IOO throughapertures iu contiguous insulating blocks of wood, such blocks being drawn in or loosely inclosed within a pipe, the space being filled wit-h insulating material; and I do not, therefore, claim such subject-matter.

I claim as my inveutionl. The combination of a conductor or series ot' conductors, iiisulating-lmttons strung thereon, and a metallic sheath or pipe formed around the cable, as described.

2. rIhe combination, substantially as set forth, of a conductor or series of conductors, a series of abutting iucombustible insulatingbuttons strung thereon, and a lead sheath formed thereon, as described.

3. The combination, substantially as set forth, of a conductor or series of conductors, a series of abutting incoiubustible insulatingbuttons strungthereon,a metallic sheath :formed thereon, as described, and an insulating compound which occupies the space around and between the cond uetor or conductors and buttous.

In testimony whereof I have hereunto subscribed my naine.

P. B. DELANY.

Witnesses:

\V. XV. TUeKER, EDwD. A. CALAHAN.

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