Patented June. 22, 1937. 2,084,866
UNITED STATES PATENT OFFICE.
2,084,866
HIGH VOLTAGE INSULATOR
Bentley A. Plimpton, Victor, N.Y., assignor to Locke Insulator Corporation, Baltimore, Md., a corporation of Maryland
Application July 3, 1935, Serial No. 29,721
2 Claims. (Cl. 173-318)
The
invention relates to high voltage insulators, particularly those of the
one-piece pin type, and has for its principal object the provision of a
novel Insulator characterized by possessing greater leakage distance and
higher flash-over value than those of ordinary design, and capable of
better operation under dirt, dust and fog conditions. Another
object of the invention is to provide an Insulator of this character in
which the exterior is of such design as to provide a long leakage
distance, and in which the interior design is of such character that
certain of the walls will remain dry, there being moreover an annular
pocket which will catch warm air rising from the earth in the daytime
and retain it, thereby preventing the condensation of moisture on the
surface which results In sparking from drop to drop of moisture and
consequent radio interference. Another
object is to provide an insulator having a preliminary cavity therein
which will catch the full force of swirling air currents laden with
moisture or dust and direct them away from the Internal pocket
containing the warm dry air. An
additional object is to provide an insulator having these advantageous
characteristics and which will at the same time be simple and
inexpensive to make by any of the ordinary methods which, being of one
piece, does not involve any assembling and which will moreover be not
only efficient but durable in service. To
the attainment of the foregoing and other objects and advantages, the
invention preferably consists in the details of construction and the
arrangement and combination of parts to be hereinafter more fully
described and claimed, and illustrated in the accompanying drawing in
which: The
figure is a view partly in elevation and partly in section illustrating
the Invention. Referring
more particularly to the drawing, I have shown the Insulator as of
one-piece construction and formed of appropriate dielectric material,
preferably porcelain. The
device is represented as consisting of a generally cylindrical body 10
provided at Its top with an upstanding reduced extension 11 transversely
grooved at 12 for the reception of a line conductor and peripherally
grooved at 13 for the accommodation of the usual tie wire for holding
down a conductor In the well known manner. The top of the body slopes
from the groove 13 downwardly and outwardly as indicated at 14. Formed centrally of the underside of the body is a cavity 15 and also a socket 16 in the latter of which is preferred to provide a metallic thimble 17 cemented in place and of threaded form so as to be screwed upon the usual supporting pin. It is of course conceivable that the thimble might be of some other shape or might even be omitted without departing from the essence of the invention. A very important feature is the formation of an annular groove 18 leading into the cavity 15 and defining a depending portion 19 concentric with the socket 16. The cavity 15 has a substantially vertical wall 20 which is a continuation of the outer wall of the groove 18. Outwardly of the cavity 15 the lower edge of the body is formed with an annular groove 21 defining a main or outer skirt 22 and a petticoat 23 spaced inwardly thereof. In
order to provide a long external leakage path the periphery of the body
is formed with a series of corrugations or alternating ribs and grooves
24 and 25, respectively. The insulator is mounted and used in the same manner as others of the same general type but in service it will perform far more efficiently than those of the conventional designs, this being so for numerous reasons. In the first place, the series of corrugations on the exterior will provide a long leakage path as mentioned above. Moreover these corrugations are freely exposed to wind and rain and will therefore be what might be called self-cleaning or in other words there |
will be no opportunity for the accumulation thereon either of water, dust
or other substances which may be in the air and which are frequently
found particularly in the neighborhood of cement mills and chemical
plants. Water falling upon the insulator or fog condensing upon it will
pass off at the lower edge of the skirt 22. The groove 21 defines what
might be termed a preliminary cavity, the surfaces of which will be dry
because of the substantially vertical walls which will discourage the
creeping of surface moisture along the inner surface of the skirt 22 and
the outer surface of the petticoat 23. Moreover this groove 21 will have
a tendency to catch the full force of swirling air currents laden with
moisture or dust that pass under the bottom of the insulator and will
direct them away from the large or inner cavity 15. The cavity 15 is
large, spacious and deep and it and the groove 18 in particular will
retain a large volume of warm, dry air that will be caught during the
day from warm air rising from the earth. This will keep the practically
vertical wall 20 and also the wall of the depending portion 19 dry and
prevent the
condensation of moisture on these surfaces which would result in causing
sparking of leakage currents from drop to drop of moisture. These wet
and dripping conditions on the interior of insulators of conventional
designs are a productive source of radio interference. For
the foregoing reasons the insulator has proved to be highly satisfactory
in every respect and to be quite superior to those of ordinary design.
From the above it is believed that the construction and benefits will be
readily apparent to one skilled in the art without further explanation. While
I have shown and described the preferred embodiment of the invention and
a certain definite location and relation between the grooves and other
similar features it will be understood that the disclosure is merely
illustrative of the principles involved and that the right is reserved
to make whatever changes constitute no departure from the spirit of the
invention or the scope of the claims hereunto appended. Having
thus described the invention, I claim: 1.
An insulator comprising a dielectric body formed in its underside with a
pin receiving socket and having its bottom provided with a cavity
communicating with said socket, said cavity leading into an annular
groove located outwardly in spaced relation to the socket and defining a
depending portion within which the socket is located, the bottom edge
being further formed with an annular groove extending upwardly and
located between the wall of said cavity and the external periphery,
thereby defining an outer skirt and an inner petticoat in spaced
relation thereto in combination with a series of alternating ribs and
grooves formed on the exterior. 2.
A high voltage insulator comprising a dielectric body having its
underside formed with an upwardly extending cavity, the top of the
insulator having its underside formed with a depending projecting
portion extending into the cavity and defining with the wall thereof an
annular groove, said downwardly projecting portion being formed with a
pin receiving socket, said groove providing a space for the entrapment
of air, said cavity having its outer wall substantially vertical, and
the lower edge of the body being formed with an upwardly extending
annular groove located between the wall of the cavity and the outer
periphery and defining an outer skirt and an inner petticoat spaced
therefrom, said last named groove providing a space within which
swirling air currents may be caught, in combination with a series of
alternating ribs and grooves formed on the periphery of the body and
extending at right angles to the longitudinal axis thereof. BENTLEY A. PLIMPTON. |