USRE2717E - Improvement in insulators for telegraph-wires - Google Patents

Description

UNITED STATES p PATENT OFFICE.

IMPROVEMENTIN INSULATORS FOR TELEGRAPH-WIRES.

Specification forming part of Letters Patent No. 45,221, dated November 29, 1864 Reissue No. 2,717, dated August o, 1857.

To all whom it may concern:

Be itknown that I, DAVID BROoKS, of Philadelphia, Pennsylvania, have invented an Imprcvcinent in Insulators for Telegraph-Vires and 1 do hereby declare the following to be a full, clear, and exact description of the same.

My invention consists ofthe improved mode, fully described hereinafter, of constructing insulators for telegraph-wires, whereby the holder to which the wire is attached is efectually insulated, and the inconveniences resulting from the collection of water on and about the insulators during rainy and foggy weather are obviated. f

In order to enable others skilled in the art "to makeand-use my invention, I will now proceed to describe its construction and operation, reference being had to the accompanying drawings, which forms a part of thich specilication, and in which- Figure 1 is an exterior View of an insulator for telegraph-Wires constructed according to my improvement and Fig. 2, a vertical section of the insulator inverted.

A is the exterior cast-iron casing ofthe insulator, the projection a of which serves as a melons oi' attachment to the arm of telegraphpo e.

B is a cylindrical block of glass, between which and the interior of the casing A intervenes a body, D, of sulphur, the glass being considerably shorter than the casing. In this glass block is a circular opening for the reception of the wire-holder G, which is secured by a mass of sulphur, II, the stem'of the holder being made concave at opposite sides, so that .it cannot be withdrawn from the glass by the weight or tension of the wires.

.In preparing my improved insulators, I in the first instance place the glass on a table or sla and pourinto the opening melted sulphur, ca

.G iu the opening of the then deposit the stem of the wire-holder glass, which is perw fectly .secured to the holder when the sulphur has become hard by ce After this Icement :to the upper edg er' the' glass a strip of peper, h, riads in the form of a hollow cy1in der,"vhen the glass with its wire-holder is ready for attachment to the casing A. In order to do this, I in the first instance heat the casmg and then pour into c same asuitable the casin g A are then trimmed olf, after which while the insulator is still in an inverted position, molten paraiiine is poured into the space above the glass within the paper cylinder until the space is full and the paper and sulphur havebecome thoroughly saturated with the paraiine. The insulator is then inverted andthe greater portion of themolten parafne is poured out, the remainder adhering to the paper and to the upper edge of the-casing and sulphur, care being taken that the coating i of parafne extends over the edge of the casing. When the coating' of parane has congealed the in sulator is ready for being attached to the pole in the position seen in Fig. 1.

Although sulphur aords an excellent medium for securing the wire-holder to the glass and the latter to the exterior casin g of the insulator, and although when dry it is a comparatively good non-conductor of electricity,

it has a great affinity for water, with which, during rains or fogs, it soon becomes `charged to such an extent as to neutralize'its non-conducting properties; hence during rainy weather electric currents would pass from the edge of the casing to the wireholder and through the paper were it not for the parane, which penA strates the sulphur and paper, adheres to the surface ot the same, and eftectually prevents these materials from absorbing moisture, while the surface of the parane is much less'liable to become coated with moisture than the surface of glass, sulphur, or other materials. The stem of the wire-holder is also coated with parafluc, and when paratilue of the best quality cannot be obtained, and is consequently liable to melt at a low temperature, it may be protected by a coating of .varnish applied to the surface. y

1 claim as my invention and desire to secure 1. The use, in the manner described, of a ho i low cylinder, h, of paper or its equivalent, iu connecting the glass block B to the casing A by means 'of sulphur.

2. The use of the paraine as an insulating In testimony whereof I have signed my name medium in telegraphimwire insulators, in the to this specification before two subscribing witmauner described, or in any other manner by nesses. Y which the same result is attained, DAVID BROOKS.

3. Theuse,in Connection with telegraph-wire Witnesses: l insulators, of sulphur or other porous cement CHARLES E. FOSTER, saturated with paraine. v 'W. J. R. DELANEY.

Images