To all whom it may concern:

Be it known that I, WILLIAM I. WALTHER, of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Insulator for Electric Circuits, of which the following is a specification, taken in connection with the accompanying drawings, making a part hereof.

The object of my invention is to provide insulators of glass, porcelain, or the like which while in all respects, considered electrically, are as efficient as others of like size are yet much less easily broken and are far better adapted to resist injury from the blows to which they are subjected in handling and from projectiles often thrown against them when in place; and my invention consists in an insulator with the usual saucer-shaped body and central projecting sleeve, but with ribs extending between the outer surface of the sleeve to the inner surface of the saucer.

In the drawings, Figure 1 is a section, and Fig. 2 an under plan view, of one of my insulators, the section being taken on line 1 1 of Fig. 2.  Fig 3 is a section on line 3 3 of Fig. 2, and Fig. 4 is a partial section on line 4 4 of

Fig. 2.

The saucer A and sleeve B are as usual, except as each is modified by the radial ribs D,

which act to strengthen both and to cause each to sustain the other, and it is this feature which is the distinguishing characteristic of my invention.    

I have shown the under side d of each rib D straight and slightly above the rim of the saucer A, and this is the preferred form, although the under side of the ribs D may be practically flush with the rim of the saucer and slightly curved, so that it joins the sleeve B nearer the lower end of that sleeve than is shown, thereby somewhat strengthening the threaded portion b of the insulator; but the form shown gives very great strength to all parts of the insulator, and it is better that the under side d of each rib shall be well above the rim of the saucer A, as shown.

The knob a on the outer surface of saucer A is as usual and needs no description.

What I claim as my invention is--

The insulator above described with its saucer-shaped body and centrally- projecting sleeve united by ribs integral with the sleeve and saucer.

        WILLIAM J. WALTHER.

Witnesses:

J. E. MAYNADIER,

C. B. MAYNADIER.