Improvement in Insulated Pipe Couplings.
Year: 1899

page_text: Date of Application, 20th Mar., 1899-Accepted, 17th Mar., 1900
COMPLETE SPECIFICATION.
Improvement in Insulated Pipe Couplings.
I, SOLOMON ROBERT DRESSER, of Bradford, in the County of McKean, and
State of Pennsylvania, one of the United States of America, Inventor, do
hereby declare the nature of this invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement:-
My invention is an improvement in pipe couplings and consists in the novel
features hereinafter described, reference being had to the accompanying draw-
ings which illustrate one form in which I have contemplated embodying. my
invention and said invention is fully disclosed in the following description and
claims.
Referring to the drawings,
Figure 1 represents a sectional view of the meeting ends of two sections of
wrought iron or other pipe connected by my improved coupling.
Figure 2 is a sectional view showing the parts of the coupling separated.
Figure 3 is an end view of one of the elastic packing and insulating rings.
Figure 4 is a view similar to Fig. 1 showing my invention applied to cast
metal pipe in which one end of each pipe is provided with an integral bell and
clamping plate.
Figure 5 is a plan view of a one piece clamping plate, and
Figure 6 is a similar view of a clamping plate formed in two parts adapted
to be united by the clamping bolts of the coupling.
In cities where electric. railways and underground electric conductors are
employed much expense and annoyance is occasioned by the leakage of electri-
city being taken up by gas, water and other pipes producing by electrolytic
action a disintegration of the pipes affected resulting in a partial destruction
of the pipes and a leakage of the fluids conducted through the same. Owing
to the fact that the sections of pipes are in .electrical connection with each
other through the thimbles or other couplings connecting them. this electrolytic
action may take place at a considerable distance from the point at which the
current enters the pipe and may extend throughout a long section of piping.
In order to prevent as far as possible this electrolytic action. from being set
up and to limit its action as much as possible in case such action takes place,
it is the object of my invention to provide a coupling for such pipes which in
addition to uniting the adjacent ends of the pipe sections will insulate each
section from its adjacent sections. By this means the electrolytic action will
be in a large measure prevented altogether and if the conditions are favorable
to such action it will only take place within a single section of the pipe.
In Figs. 1, 2 and 3 I have shown my invention embodied in a coupling for
the meeting ends of two sections of ordinary wrought iron or other pipe having
plain ends. A A represent the pipe sections, the meeting ends of which are
not threaded. B B represent clamping plates which in this instance are formed
in one piece as shown in Fig. 5. Each of these plates is provided on its face
with a circular recess 6 of greater diameter than the pipe A, the walls of said

page_text: recess being curved or tapered inwardly toward the outer face of the plate as
at b, where a concentric circular aperture 62 is formed of a diameter only
slightly greater than the pipe A. The portion of the plates B B¹ between the
walls of the recess and the outer edges of the plate are cored or recessed to
make them lighter and each plate is provided with bolt holes 63 and strengthen-
ing ribs or webs 64 extending radially and connecting the inner portions and
the outer portions as shown in Fig. 5.
C represents a packing and insulating, ring which is preferably formed of
rubber molded in the desired shape although it may be formed of any other
suitable material which will answer the same purpose. This ring Chas a
⚫ central aperture of substantially the size of the pipes A and is provided with
an enlarged portion e adapted to fit within the recess 6 of one of the clamping
plates B B and having a curved outer face to conform to the shape of said
recess. Said ring is also provided with an elongated sleeve portion which is
adapted to extend through the central aperture of the clamping plate.
If the ring C is inserted within one of the clamping plates and then slipped
over one end of a pipe as in Fig. 1'the pipe will be entirely insulated from
the clamping plate. The ring C at the end opposite the sleeve portion c¹ is pro-
vided with an annular recess preferably V-shaped in cross section to receive
one end of a coupling sleeve D formed of metal, having a central aperture and
having its edges at each end formed in a V-shape in cross section. The central
bore of the sleeve D is preferably increased at one end of the same as shown
at d d to receive an insulating sleeve E having an internal diameter sufficient
to enable it to be slipped over the end of one of the pipe sections and provided
at one end with an inwardly extending annular flange e, which engages the
end of the pipe section as shown in Fig. 1 and thus prevents the adjacent ends
of the pipe sections A A from touching each other. It is obvious that I may
provide each of the meeting ends of the pipe sections with one of these insulat-
ing sleeves E if desired but I have found that it is sufficient to provide one of
said sleeves adjacent to the insulating and packing ring C. C₁ represents a
packing ring in all respects similar to the ring C except that it is not provided
with the sleeve portion, said ring C₁ being formed to fit the recess & in one of
the clamping plates and having the annular groove 3 V-shaped in cross section.
It is obvious however, that instead of employing the rings C and C¹ I might
employ two of the rings C.
In uniting the ends of two pipe sections with this form of device the clamp-
ing plates are slipped over the ends of the pipes and moved in opposite direc-
tions from the ends to enable the other parts to be placed in position. One of
said pipe ends is then provided with the insulating and packing ring C and the
insulating sleeve E and the other pipe end is provided with the ring C (or
another ring C) and the metal coupling sleeve 1) is then slipped over the insulat-
ing sleeve E as before described. The rings C C are then moved toward the
coupling sleeve D until the ends of said sleeve are seated in the annular
grooves of the said rings. The coupling plates are then placed in position
upon the rings C C as shown in Fig. 1 and clamping bolts F F are passed
through the bolt holes 63 of said plates and provided with nuts f by means of
which the plates B B are drawn toward each other thus clamping the parts
together and forming a tight joint. The plates B B¹ are each provided adja-
cent to two or more of the bolt holes (preferably two as shown in Fig. 5) with
parallel projections or webs 65 to engage the heads of the bolts and prevent
them from turning. This construction enables two of the bolts to be inserted
from each end of the coupling, and the clamping plates can thus be cast exactly
alike. It will be observed that the pipe section A which engages the ring C is
entirely insulated from the adjacent pipe section and from the clamping plate
through which it passes, so that the electric current cannot pass through the
coupling from one pipe section to the other.
In Fig. 4 I have shown my invention applied to a bell and spigot coupling

page_text: for cast metal pipe in which each section of pipe has a bell and clamping plate
cast integrally with it. In this figure G represents one of the pipes, one end
of which is plain and the other is provided with the integral clamping plate or
flange having bolt holes extending therethrough and having the annular bell g¹.
the outer edges of which are V-shaped in cross section. The bell g' is of
sufficient size to receive an insulating sleeve H (similar to the sleeve E pre-
viously described) adapted to fit over the plain end of the next adjacent pipe
section and having at one end an inwardly extending flange h to prevent the
end of the pipe from engaging the bottom of the hell. I represents a packing
and insulating ring (similar to the ring C previously described) having the
enlarged portion provided with a curved outer surface to fit within the
clamping plate recess, the sleeve portion 2 and the annular recess 23 V-shaped
in cross section to receive the end of the bell. K represents the clamping
plate (similar to the ring B heretofore described) and connected by bolts L L
to the clamping flange g. In this construction it will be seen that the end of
the pipe which enters the bell g is entirely insulated from the bell and from
the clamping plate K through which the pipe passes. It is obvious that in-
stead of using the insulating sleeves E H hereinbefore described, I may simply
wrap the portion of the pipe adjacent to the end with insulating material but
I prefer to use said sleeves. In this form of my invention the retaining webs
or projections on the clamping plate may be omitted and the clamping flange
provided with shoulders 2 to engage the heads of the bolts and prevent them
from turning as shown in Fig. 4.
In some cases I may prefer to form the clamping plates in two parts as indi-
cated in Fig. 6 for the purpose of enabling them to be more readily placed upon
the pipes and removed therefrom and for the purpose of making quick repairs
without disturbing the adjacent ends of the pipes unnecessarily. In such case
the two parts M M of the plate will be provided with overlapping portions m m
through which the two of the bolt holes pass so that the clamping bolts will
also serve to hold the parts of the plates together.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is:―
1. The herein described combination of a clamping ring provided with an
aperture therethrough, a pipe section having a uniform diameter throughout
its length less than the diameter of the aperture in said ring and passing
through said aperture, a second pipe section, means for insulating the pipe
sections from each other, means for insulating said first mentioned pipe section
from the ring through which it passes and means for compressing the insulating
material by a movement of the clamping ring longitudinally of the pipe sections.
whereby said pipe sections are insulated from each other, said ring is insulated
from the pipe section passing therethrough and provision is made for the move-
ment of the said pipe section through said ring to allow for expansion and con-
traction, substantially as described.
2. The herein described combination with two pipe sections, of a clamping
ring for each pipe section, provided with an aperture through the same for the
passage of its pipe section therethrough, means for insulating the adjacent ends
of said sections from each other, means for insulating each of said rings from
the pine section passing therethrough, clamping means for drawing said rings
toward each other to compress the insulating material, whereby said pipe sec-
tions are insulated from each other, each pipe section is insulated from the ring
through which it passes and provision is made for the free movement of each
of said pipe sections through their respective rings and through the insulating
material to allow for longitudinal expansion and contraction, substantially as
described.
3. A pipe coupling for uniting the adjacent ends of pipe sections and insulating

page_text: them from each other, including among its members, a cylindrical portion,
a clamping plate adapted to surround one of said pipe sections and provided
with clamping bolts, and an insulating and packing ring having a portion inter-
posed between said cylindrical portion and said plate and an insulating sleeve
portion surrounding said pipe section between it and said plate, substantially as
described.
4. A pipe coupling for uniting the adjacent ends of pipe sections and
insulating them from each other including among its members a cylindrical
portion adapted to extend over the end of one of said pipe sections, a clamping
plate adapted to surround said pipe section and provided with a packing recess
on one side, and a packing and insulating ring having a portion adapted to
be interposed between the said cylindrical portion and said plate and to occupy
said packing recess and an insulating sleeve adapted to extend between said
plate and said pipe section, substantially as described.
5. A pipe coupling for uniting the adjacent ends of pipe sections and insu-
lating them from each other including among its members, a cylindrical
portion to receive one end of a pipe section, provided with an annular edge
V-shaped in cross section a clamping ring adapted to surround the pipe section
the end of which is inserted in said cylindrical portion, provided with a packing
recess, and clamping bolts, and a packing and insulating ring adapted to fit
said packing recess, provided on one end with an annular groove V-shaped in
cross section to receive the end of said cylindrical portion and at the other end
with an insulating sleeve portion interposed between the said plate and said
pipe section, substantially as described.
6. A pipe coupling for uniting the adjacent ends of pipe sections and insu-
lating them from each other including among its members a cylindrical
portion to receive one end of a pipe section provided with an annular edge
V-shaped in cross section, a clamping ring adapted to surround the pipe section
the end of which is inserted in said cylindrical portion, provided with a packing
recess, and clamping bolts, and a packing and insulating ring adapted to fit
said packing recess, provided on one end with an annular groove V-shaped- in
cross section to receive the end of said cylindrical portion and at the other end
with an insulating sleeve portion interposed between the said plate and said
pipe section, and insulating material engaging the end of said pipe section, sub-
stantially as described.
7. A pipe coupling for uniting the ends of two pipe sections and insulating
them from each other comprising among its members, two clamping plates
adapted to surround said pipe sections, each provided with a packing recess
and apertures for clamping bolts, a coupling sleeve adapted to extend over the
adjacent end portions of the said pipe sections, packing rings adapted to engage
said packing recesses and to engage the ends of said sleeve, one of said rings
being provided with an insulating sleeve adapted to be interposed between one
of said pipe sections and the clamping ring through which it passes and the
clamping bolts, substantially as described.
8. A coupling for uniting the adjacent ends of pine sections and insulating
them from each other, comprising among its members, two clamping plates
each provided with an aperture for the passage of the pipe therethrough and a
packing recess, a coupling sleeve adapted to cover the adjacent portions of the
pipe sections between said plates, the packing rings engaging said packing
recéssés. and adapted to engage the ends of said sleeve, one of said rings being
provided with an insulating sleeve adapted to lie between one of said plates
and the pipe passing therethrough, insulating material interposed between the
ends of said pipe sections and the clamping bolts for uniting said clamping
plates, substantially as described.
9. A coupling for uniting the adjacent ends of pipe sections and insulating
them from each other, comprising among its members, two clamping plates
each provided with an aperture for the passage of the pipe therethrough and a

page_text: packing recess, a coupling sleeve adapted to cover the adjacent portions of the
pipe sections, between said plates, the packing rings engaging said packing
recesses, and adapted to engage the ends of said sleeve, one of said rings being
provided with an insulating sleeve adapted to lie between one of said plates
and the pipe passing therethrough, an insulating sleeve engaging said pipe
within the coupling sleeve, and having a flange engaging the end of the pipe,
and the clamping bolts for uniting said clamping plates, substantially as
described.