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To all whom it may concern: Be
it known that we, JAMES PASS and ALBERT P. SEYMOUR, citizens of the
United States, and residents of Syracuse, in the county of Onondaga and
State of New York, have invented certain new and useful Porcelain
Insulators, of which the following is a specification. Our
invention relates to line-insulators for electric wires, and more
particularly to that class comprising a socketed block or piece of
glass, porcelain, or similar vitreous substance adapted to fit upon a
supporting-pin, the socket and pin having each a screw-thread or being
plain, as desired. Our
invention is designed expressly for porcelain insulators in which the
socket has a screw-thread, although applicable to other materials as,
for instance, glass and to plain sockets. The
object of the invention is to provide an efficient and serviceable
insulator; and it consists in the features of construction and details
hereinafter described, and then specified in the claims. In
the accompanying drawings, Figure 1 is a vertical central section
through an insulator constructed in accordance with our invention. Fig.
2 is a similar section through the porcelain or similar shell before the
application of the cement. A
is the body of the insulator, formed of a shell or block of insulating
material closed at one end and open at its other, said shell being,
roughly speaking, of an inverted-cup shape, the interior of which
constitutes the socket into which the supporting-pin enters, while the
edges form a skirt or petticoat adapted to shed water and more fully
insulate the wire from the supporting-pin. The shell or block shown is
made, preferably, of porcelain and of the shape shown in Fig. 2. The
whole surface may be glazed, or the interior from the shoulder a
inward may be, and preferably is in our invention, left unglazed. This
interior surface is also preferably provided with one or more
longitudinal and vertical ribs or grooves in order to more effectively
hold the cement B, which consists of a mass of porous cementing
substance-- like, for instance, plaster-of-paris cast in the shell
after the finishing of the latter The
purpose of leaving the porcelain unglazed is to assist the union of
cement and the shell. In
the mass B is formed the socket which receives the supporting pin.
If the socket be screw-threaded, the screw thread may be formed
or molded in the casting operation. C
is a bushing of metal for the socket. This bushing is of thin metal and
made in any desired way and of any desired material. For
cheapness we use lead and we may make the bushing by casting the lead on
an iron screw, which is dipped into a pot of melted lead and then
withdrawn, the lead adhering being sufficiently thick to make the
bushing and being readily |
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withdrawn from the mold on cooling. The slight irregularities in a bushing thus formed serve to more effectually hold it in the cement which is cast around it. After casting the cement the insulator is baked or heated with paraffine, filling the interior, so as to thoroughly saturate the porous cement with such water-repellant material and the superfluous paraffine afterward removed. Instead of paraffine, any other water repellent substance might be used which would readily be taken up by the porous cement; but we prefer paraffine. The thin metal bushing protects the cement from injury. We do not, however, limit ourselves to the use of the attached metal bushing, as this part might be omitted. We prefer, however, to use the bushing applied and held as described. If the bushing be not used, it is obvious that the screw-thread of the socket would be formed by a mold which would be withdrawn from the cement before the latter hardens. What we claim as our invention is-- 1.
A line-insulator, of porcelain or similar insulating material, having
its socket, which fits upon a supporting-pin, formed in a mass of a
porous cement east within the insulator and saturated with paraffine or
similar water-repellent substance. 2. A line-insulator consisting of a porcelain shell
glazed, excepting at its socketed part, and provided with a mass of
porous cement cast in such unglazed part and saturated with paraffine or
similar material. 3. In a line-insulator, a socketed block of porcelain or
other vitreous insulator having a
socket formed in a mass of cement within the block and provided with a
thin metal bushing around which the cement is cast. 4.
As a new article of manufacture, a porcelain line-insulator having its
socket formed in a mass of porous cement cast in the insulator and
saturated with paraffine or similar water-repellent substance, and a
bushing of thin metal
lining said socket and held fast
by the cement. 5.
A line-insulator consisting of a porcelain cup-shaped shell provided on
its interior with the longitudinal and vertical ribs or grooves, in
combination with a mass of porous cement cast in said shell and
saturated with a water-repellent substance and a socket in said cement
lined with a protective bushing, as and for the purpose described. Signed
at Syracuse, in the county of Onondaga and State of New York this 7th
day of March, A. D l892.
JAMES PASS.
ALBERT P. SEYMOUR. Witnesses:
SOLON H. LANE, CHAS. R. HUBBELL. |