Title of Invention

AN IMPROVED LOCKED COUPLING BETWEEN TWO TUBLAR ELEMENTS

Abstract This invention relates to an improved locked coupling between two tubular elements (1, 1A) one of said elements having a spigot end (2) and the other being a socket (4) said coupling comprising a set of withdrawable bolts (6, 6') capable of being fixed to said socket (4) by operating said bolts (6, 6') from outside. Said bolts (6, 6') are capable of being tightened by screws to an extent, so that the free ends of the bolts (6,6') remain within a cavity (7, 7') provided on the outer surface of said socket (4).
Full Text The present invention relates to pipe coup lings for joints and
more particularly to couplings for pipes having joints of sockets
and spigots. The invention particularly relates to an elastomeric
sealing element and a locking device for preventing a relative
longitudinal displacement of the two-coupled pipes. The invention
is applicable to pipes made of metals, ceramic concrete, plastics
or other compositions.
It is well known in the art to which the invention relates that
the internal pressure in a pipeline will exert forces tending to
separate or break the joints in the line wherever there is a
change of direction, a branch, or a dead end in the pipeline. It
would be desirable if the joints themselves would provide the
necessary resistance to separation or breakage; however, the slip
on or push-on joints in common use today for the joining of pipe
do not provide any appreciable resistance to separation. For
example, Indian Patent No, 60,440 dated March 17, 1958.
Accordingly, it has been necessary to provide external means such
as concrete blocking or clamp and tie rods along a pipeline in
order to prevent relative movement of pipe sections, which would
result in separation of the joints. such commonly used meant
accomplish the desired purpose, but are very expensive and time
consuming.
An object of the present invention is to mitigate the foresaid
drawbacks of the conventional jointing of pipes.
A further object of the present invention is to provide anchoring
or securing of flexible pipe joints and safe guarding them
against relative longitudinal displacement of two coupled pipes.
Another object of the invention is to provide couplings and
fittings when they require fluid tight separation resistant joint
between socket and spigot elements.
Accordingly there is provided an improved locked coupling
between two tubular elements. One of said elements having a
spigot end and the other being a socket . The coupling
comprising a set of withdrawable bolts capable of being fixed
to said socket by operating the bolts from outside. The bolts
are capable of being tightened by screws to an extent so that the
free ends of the bolts remain within a cavity provided on the
outer surface of said socket .
Thus, a fluid tight joint similar to pipe joints and gaskets of
the kind disclosed for socket and spigot type pipe couplings and
fittings, comprising a spigot member having a generally
cylindrical end portion, a socket member receiving said spigot
member and having an axially elongated gasket groove therein
radially opposite the cylindrical end portion of the spigot
member, said gasket groove being defined by the internal wall of
a lip with said lip extending toward the spigot member and a
generally axially extending wall, the diameter of said lip at its
inner extremity being slightly greater than the external diameter
of the spigot member, an........................................
axially elongated annular gasket having a portion thereof in
engagement with the axially extending wall of the gasket groove
and the general cylindrical end portion of the spigot member
under radial compressive force whereby seal is effected between
the socket and spigot members.
It is known that the coupling of pipes having a socket end and a
spigot end is liable to be disconnected under the action of an
internal pressure and/or external forces.
The present invention provides an improved locked coupling
between two tubular elements, one of said elements having a
spigot end and the other being a socket, said coupling
comprising a set of withdrawable bolts capable of being fixed to
said socket by operating said bolts from outside, said bolts
being capable of tightened by screws to an extent, so that the
free ends of the bolts remain well within a cavity or slot
provided on the outer surface of said spigot.
In the above improved locked coupling, the set of bolts is fitted
from within said spigot onto said socket so that free end of said
bolts remain well within a cavity provided in said spigot. The
bolts are preferably made of stainless steel.
The socket of the improved locked coupling is provided with a
inner rim and the spigot is provided with a set of holes so that
when said socket and spigot are assembled for coupling , the
holes are located between said rim and the rear end of said
socket for the entry of said bolts.
Furthermore, a sealing element of resilient material is
placed in the space located between the spigot and the socket.
The said sealing element is preferably made of rubber or like
material.
The improved locked coupling of the present invention may
further comprise a set of holes fitted to said socket so that
free end of said holts remain will within a cavity or slot
provided on the outer side of the spigot.
The present invention further comprises a process of locking
axial displacement between two tubular elements one of which
elements has a spigot end and the other has a socket. The locking
device comprising of withdrawable bolts radially placed screwed
through the spigot and passes through the cavity provided in the
socket. The arrangement being such that the bolts are capable of
preventing the spigot end to withdraw from the socket when the
spigot end is subjected to an axial thrust in a direction to tend
to separate the two tubular elements, wherein the spigot end is;
pushed cut of the socket after the bolts are radially placed
around the spigot,
Several embodiments of this invention will be described below by
way of example with reference to the accompanying drawings,
wherein-
Fig, 1 is a longitudina1 axial radial sectiona1 view of a
coupling according to the invention with bolts in position from
outside the socket through the hole in the spigot.
Fig. 2 is another longitudinal axial radial sectional view of a
coupling when the set of bolts are screwed from outside the
socket through the slot in the spigot.
Fig, 3 is. another longitudinal axial radial sectional view of a
coupling when the set of bolts are screwed from inside the pipe
through the spigot to the hole in the socket such that it passes
through the spigot and passes through the hole provided on the
socket and places itself inside the hole of the socket.
Fig.4 is another longitudinal axial radial sectional view of a
coupling when the set of bolts are screwed from inside the pipe
through the spigot to the cavity provided in the socket adjacent
to the cavity where the gasket is fixed.
Fig.l to Fig.4 describe several embodiments of this invention
related to joints, which are known as Push-on-joint in the trade.
Fig,5 illustrates another longitudinal axial radial sectional
view of a couplng when the set of bolts are screwed from outside
through the outside of socket of the type well known as common
mechanical joint, such that it passes through the mechanical
joint socket and passes through the hole provided on the spigot
and places itself inside the hole of the spigot.
These and other objects of the invention will appear more fully
upon consideration of the detailed description of the illustrated
embodiments of the invention, which follows. In this connection,
although several different embodiments of the invention ere
illustrated and described, it is to he explicitly understood that
these embodiments are intended merely for the purpose of
illustration and are not to construe as defining the limits of
the invention. It will also be understood that, while the
drawings show joints between sections of socket and spigot type
pipe, the invention is equally applicable to couplings and
fittings when they require a fluid tight separation resistant
joint between socket and spigot elements.
In the above drawings., Figs 1 and 2, a restrained jont (5)
comprises a first tubular element (1) having a spigot end (2) and
a second tubular element (1A) provided with a socket (4). A
rubber gasket (3) is placed in an annular space between the first
tubular element (1) and the socket (4) which when assembled seals
the joint (5) against leaking. A first coupling comprises a set
of withdrawable bolts (6,6') capable of being fixed to said
socket (4), the arrangement being such that the bolts (6,6') can
be turned from outside the socket (4) and passes into a hole
(7,7') in the first tubular element (1). The bolts (6,6') are of
such length that they do not protrude inside the tubular spigot
element (1) and there is no obstruction of fluid from inside.
When the set of bolts (6,6') are screwed from outside the socket
into the hole (7,7') provided in the spigot (2) in an assembled
positions When the spigot (2) is subjected to an axial thrust in
a direction tending to separate the two tubular elements (1,1A),
the bolts (6,6') come in the way of pushing out the spigot (2).
The entire thrust force to separate th» two tubular elements
(1,1A) is taken by the shear strength of the set of bolts (6,6'
radially placed in the socket (4) from outside.
In figures 3 and 4, the bolts (6,6') are turned from inside when
the diameter of the tubular spigot element (1) is such that a
man can enter into it after the joint is assembled. The bolts
(6,6') are tightened to such an extent that they do not protrude
inside the tubular element (1) and there is no obstruction of
fluid flow from inside. The other ends (8,8') of the sets of bolts
(6,6') protrude on the other side of the spigot (2)» which
remain in the cavity (7,7') provided in the socket (4).
Due to formation of a compartment (9,9') in the socket (4), the
set of bolts (6,6') do not interfere with the joining of tbe push-
on joint and leak tightness of the joint. But as the (6,6) bolts
protrude inside the socket (4) in the event the spigot (20) is
subjected to an axial thrust tending to separate said two tubular
elements (1, 1A), the bolts (6,6') come in the way of pushing out
the spigot (2) from the socket (4). The entire thrust force to
separte the two tubular elements (1, 1A) is taken by the shear
strenght of the setoff bolts (6,6') radially present in the
spigot (2).
In Figure 3 of the arrangement, when the sets of bolts (6,6') are
screwed into the socket (4) through the holes (2) of the spigot end
(2) but do not protrude inside the spigot end (2), there is no
obstruction of the fluid from the inside. In the avent, the
spigot (2) is subjected to an axial thrust in a direction tending
to separate the two tubular elements (1, 1A), the bolts (6,6)
come in the way of pushing out the spigot (2). The entire thrust
force to separate two tubular elements (1, 1A) is taken by the
shear strength of the set of bolts (6.6') positioned radially in
the socket (4).
As shown in Figure 5, the set of bolts (6,6') are screwed from
outside through the outside of a socket (4,4') and a bolt (10)
with a worm (11) fastened from outside of the socket (4) and
passes through the hole provided on the spigot (2) and places
itself inside the hole of the spigot (2). When the bolts (6,6)
are properly fastened, the socket (4') will occupy the blank
space (12) of the socket (4).
I CLAIM:
1. An improved locked coupling between two tubular
elements (l, 1A),one of said elements having a spigot end (2)
and the other being a sockat (4),said coupling comprising a sat
of withdrawable bolts (6,6') capable of being fixed to said
socket (4) by operating said bolts (6, 6') from outside,
characterized in that said bolts (6, 6') are capable of being
tightened by screws to an extent, so that the free ends of the
bolts (6, 6') remain within a cavity (7, 7') provided on the
outer surface of said socket (4).
2. An improved locked coupling as claimed in claim 1
wherein said set of bolts (6, 6') is fitted from within said
spigot (2) onto said socket (4) so that free ends of said
bolts (6,6') remain within the cavity (7, 7') provided in said
socket (4).
3. An improved locked coupling as claimed in claim 1
wherein said bolts (6, 6') are made of stainless steel.
4. An improved locked coupling as claimed in claim 2
wherein said socket (4) is provided with an inner rim (13) and
said spigot (2) is provided with a set of holes so that when said
socket (4) and the spigot (21) are assembled, the holes are
located between said rim (13) and the rear end of said socket (4)
for the entry of said bolts.
5. An improved locked coupling as claimed in any of the
preceding claims, wherein a sealing element (3) of resilient
material is placed in the space located between said spigot (2)
and said socket (4).
6. An improved locked coupling as claimed in claim 3,
wherein said sealing element (3) is made of rubber or like
materials.
7. An improved locked coupling as claimed in any of the
preceding claims, wherein said joint further comprises a set of
bolts (8, 8') fitted to said socket (4) so that free ends of said
bolts (8, 8') remain within a cavity (7, 7') or slot provided on
the outer side of said spigot (2).
8. An improved locked coupling substantially as herein
described with reference to the drawings accompanying this
specification.

This invention relates to an improved locked coupling
between two tubular elements (1, 1A) one of said elements having
a spigot end (2) and the other being a socket (4) said coupling
comprising a set of withdrawable bolts (6, 6') capable of being
fixed to said socket (4) by operating said bolts (6, 6') from
outside. Said bolts (6, 6') are capable of being tightened by
screws to an extent, so that the free ends of the bolts (6,6')
remain within a cavity (7, 7') provided on the outer surface of
said socket (4).

Documents:

332-kol-2004-abstract.pdf

332-kol-2004-claims.pdf

332-kol-2004-correspondence.pdf

332-kol-2004-description (complete).pdf

332-kol-2004-drawings.pdf

332-kol-2004-examination report.pdf

332-kol-2004-form 1.pdf

332-kol-2004-form 13.pdf

332-kol-2004-form 18.pdf

332-kol-2004-form 2.pdf

332-kol-2004-form 3.pdf

332-kol-2004-form 5.pdf

332-kol-2004-reply to examination report.pdf

332-kol-2004-specification.pdf


Patent Number 237808
Indian Patent Application Number 332/KOL/2004
PG Journal Number 02/2010
Publication Date 08-Jan-2010
Grant Date 07-Jan-2010
Date of Filing 18-Jun-2004
Name of Patentee CHATTERJEE ARABINDA
Applicant Address EC-65, SECTOR-1, SALT LAKE CITY, CALCUTTA
Inventors:
# Inventor's Name Inventor's Address
1 CHATTERJEE ARABINDA EC-65, SECTOR-1, SALT LAKE CITY, CALCUTTA-700 064
PCT International Classification Number F16L
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA