UNITED   STATES   PATENT   OFFICE


HARRY HAMILTON COCHRANE, OF BUTTE, MONTANA.

INSULATOR.


   No. 1,194,957.                     Specification  of Letters Patent.          Patented Aug.  15, 1916.

Application filed April  21, 1915.   Serial No. 22,831.  


To all whom it may concern:

Be it known that I, HARRY H. COCHRANE, a citizen of the United States, and a resident of Butte, in the county of Silver Bow and State of Montana, have invented a new and Improved Insulator, of which the following is a full, clear, and exact description.

My invention relates to insulators and has reference more particularly to insulators for electric currents of high potential.

The object of the invention is to provide a simple, strong, efficient and durable insulator characterized by the provision of a central insulating core of fibrous nature scaled in replaceable, protective, insulating shells so that the core therein is protected from atmospheric influence.

With the above and other objects in view, the nature of which will more fully appear as the description precedes, the invention consists in the novel construction, combination and arrangement of parts as herein fully described, illustrated and claimed.

In the accompanying drawings, forming part of the application, similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a vertical central section through my insulator; Fig. 2 is a horizontal section on line 2-2, Fig 1; and Fig. 3 is a similar section on line 3-3, Fig. 1. 

Referring to the drawings, 4 represents a fibrous rod, preferably of hickory.  This rod constitutes the core of the insulator.  The ends of the rod 4 are reduced and thereon are crimped metallic cups 5.  The cups have threaded portions 6, the diameter of which is substantially the same as the diameter of the rod.   Positioned on the rod is a series of protecting, insulating shells 9 of porcelain or other similar insulating substance.  Each of these tells comprises a tubular portion 10, the bore of which is substantially equal to the diameter of the rod, so that the same fits snugly over the rod.  At one end of the tubular section a concavo-convex flange 11 is provided which depends from the tubular section and which forms the petticoat of the shell.  Located within the petticoat is an annular collar 12 concentric with the tubular portion 10 and of a diameter such as to engage the end of a successive shell 9. The engagement between the collar 12 and the tubular portion 10 of the successive shells is such that sufficient play there between is left to accommodate cement.  In view of the fact that the inner diameter of the collar 19 is greater than the inner diameter of the tubular portion, an annular shoulder 13 is formed within each shell.

The metallic cup 5 at one end of the core receives a metallic cap 14 which is threaded on to the cup 5 and the outer diameter of which cap 14 is substantially equal to the outer diameter of the tubular portion 10 of the shell, so that the same will fit loosely into the collar of a shell 9 placed on to the core to engage the cap. The shoulder 13 of each shell carries a gasket 15, preferably formed of an insulating material, such as paraffin, pitch or bitumen; which seals the contacting ends of

the successive shell as well as the engaging end of the cap 14.  The space between the cap 14 and the collar is closed by cement of insulating character, as is also the space between the successive

tubular portions and the collars in engagement therewith, as shown in Fig. 1.  Secured to the cup 5 at the other end of the rod 4 is a cap 16 which has a central recess 17 of substantially the same diameter as the inner diameter of the collars 12, so that the same will accommodate the tubular portion 10 of the shell adjacent the said end where the cap 16 is provided.  The clearance in the recess is also cemented, so that the core is perfectly sealed within the series of shells and the caps carried by the ends of the core.  Therefore, the same is insulated from the atmosphere and, consequently will not be affected by the changes thereof and will be immune from humidity, which is the cause of many troubles in insulators for currents of high potential.

The caps 14 and 15 are each provided with a staple 18 whereby the entire insulator can be supported and attached to carry the conductor.  The fibrous core is preferably impregnated with an insulating compound, such as oil or paraffin.  The transverse resistance of such a core is very great, as the fibers are disposed longitudinally.  It is substantially inflexible, and, consequently, forms a rigid unit on which the conductor can be flexibly supported, due to the provision of the staples 18.  The shells and caps, as previously described, form the protector for the core.  Due to the fact that the core is a rigid one, any of the broken shells 9 can be easily substituted by removing a cap from the ends of the core, slipping off the shells which are injured and replacing the injured shells, then replacing the uninjured shells and tying them together as previously described.

While I have described the principle of operation, together with the device which I now consider to be the best embodiment thereof, I desire to have it understood that the device shown is merely illustrative and that such changes may be made are within the scope of the appended claims.

I claim:

1.    An insulator comprising an insulator rod, metallic cups crimped to the ends of the rod, tubular insulating sections engaging the rod, metallic caps in threaded engagement with the cups, insulating gaskets intermediate the tubular sections, and means cementing the sections to one another and to the caps, substantially as and for the purpose set forth.

2.    In an insulator, a wooden rod impregnated with an insulating compound and forming the core, tubular insulating sections fitting snugly on to the rod, each of said sections having a petticoat and an annular collar within the petticoat adapted to accommodate the end of the succeeding section, an insulating gasket within the annular collar, metallic caps in threaded engagement with the cups and in engagement with the adjacent tubular sections, and means sealing the connection between the engaging sections and the sections engaging the caps.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

   HARRY HAMILTON COCHRANE.

 

Witnesses:

C. C. TILLOTSON,

JACOB AUTHORIESON.